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Columns & Departments 

COLUMNS 

4 Front Page 

Don Nelson, 

Publisher 

The buzz surrounding MEMS. 

12 Micromachining 

Alan Richter, 

Senior Editor 

Strategies for effectively boring 

microholes. 

15 Laser Points 

Ronald D. Schaeffer, 

PhotoMachining Inc. 

Factors to weigh before 

purchasing a laser. 

17 Down Sizing 

Dennis Spaeth, 

Electronic Media Editor 

Microturbine research 

recharged. 

19 Measurement Matters 

Susan Woods, 

Contributing Editor 

Gaging surface roughness 

with scanning white light 

interferometry. 

22 About Tooling 

Hugh McAllister, 

Chardon Tool 

Conventional machines can 

run single-crystal-diamond 

tools. 

52 Last Word 

Phillip M. Leopold, 

Medical Murray Inc. 

Thoughts from a medical 

manufacturing pioneer. 

DEPARTMENTS 

6 Tech News 

48 Products/Services 

50 Research Roundup 

51 Advertisers Index 

On MICROmanufacturing.com 

From μTube: 

5-axis micromilling 

Microlution’s new 5100-S 5-axis CNC micromilling machine is a 

vertical bridge-style machining center with a trunnion-style confi 

guration. Visit our Web site for a video overview of the machine. 

Grinding machine 

Highlights of Rollomatic USA’s new GrindSmart Nano6, designed 

to manufacture cutting tools with diameters from 0.01mm to 

2.0mm. 

Robot router 

A video from Micromagic Systems, a U.K. animatronics and robotics 

company, shows a hexapod CNC router that could potentially 

put a whole new face on micromachining. 

3-D microfabrication 

Researchers at the École Polytechnique de Montréal, Canada, 

have developed a 3-D microfabrication technique that uses ultraviolet 

light to cure a liquid polymer material as it is dispensed. 

6 

17 

12 

micromanufacturing.com | 1

Features 

36 

WINTER 2009 • Volume 2 • Issue 4 2 | WINTER 2009 | MICROmanufacturing 

COVER STORY: 

25 New Directions 

William Leventon 

New design strategies facilitate 

MEMS production. 

30 Taking Form 

Lowell Thomas and 

Luke Volpe, 

Dynamics Research Corp., 

Metrigraphics Div. 

Electroforming use grows as 

complex electronic devices 

shrink. 

36 Clean Machining 

Joel Cassola 

Clean rooms being used more 

for micromachining. 

40 Good Vibration 

(Control) 

Bill Kennedy, 


Countering vibration in small 

and large machine tools for 

micromachining. 

30 

40 

ON THE COVER 

Microvision Inc.’s MEMS scanning 

mirror is used in the 

company’s new hand-held laser 

bar-code scanner. Additional 

information can be found at 

www.microvisin.com. 

Cover design: Tom Wright. 

www.micromanufacturing.com 

Main Offi ce 

40 Skokie Blvd. 

Ste. 450 

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(847) 714-0048 

micromanufacturing@jwr.com 

Staff 

Publisher 

Don Nelson 

(847) 714-0173 

dnelson@jwr.com 

Editorial Director 

Alan Rooks 

(847) 714-0174 

arooks@jwr.com 

Senior Editors 

Alan Richter Daniel McCann 

(847) 714-0175 (847) 714-0177 

alanr@jwr.com dmccann@jwr.com 


Dennis Spaeth 

(847) 714-0176 

dspaeth@jwr.com 

Contributing Editors 

Bill Kennedy 

(724) 537-6182 

billk@jwr.com 

Ad Production Manager 

Julie Distenfi eld 

(847) 714-0179 

julied@jwr.com 

Art Director 

Gina Moore 

(847) 714-0178 

ginam@jwr.com 

Administrative Assistant 

Pat Jones 

patj@jwr.com 

Circulation 

Synergy Direct Inc. 

(866) 207-1448 

andrea@sdicirc.com 

Advertising Sales 

Scott Beller (East) 

(847) 714-0183 

scottb@jwr.com 

Bob West (South, West) 

(770) 730-9763 

microm_bobwest@msn.com 

Jody Nelson (Midwest, Int’l) 

(847) 714-0170 

jodyn@jwr.com 

® 

Susan Woods 

susanw@jwr.com

IMTS.com

FRONTpage Don Nelson 

Publisher 

MEMS devices: widely used, little known 

4 | WINTER 2009 | MICROmanufacturing 

Amicroelectromechanical-system device 

probably saved my life 15 years ago. At 

the very least, MEMS technology prevented 

me from sustaining massive injuries. 

I was driving an automobile involved in 

a head-on collision with a car heading the 

wrong way on an exit ramp. Both vehicles 

were traveling at 45 mph. My car had an airbag 

system that incorporated a MEMS accelerometer, 

a type of sensor. When these 

sensors experience rapid deceleration, they 

signal a control unit to deploy the airbag—a 

sequence that lasts less than 60 milliseconds. 

My airbag worked perfectly. 

Th e upshot of the story is that I spent 6 

hours in the hospital, for observation, was 

discharged and home in time for dinner. Th e 

other driver, whose car wasn’t equipped with 

an airbag, spent 4 days in the hospital’s intensive 

care unit followed by 6 weeks recovering 

from extensive external and internal injuries. 

Many people have had their lives saved 

by airbags, which became standard equipment 

on vehicles because relatively low-cost 

MEMS accelerometers made them aff ordable. 

And many, many more people have benefi 

ted from and had their lives enriched by 

MEMS devices without realizing they exist. 

Few know that the technology underlies 

the operation of inkjet printer heads; bar 

code scanners; smart phones, such as Apple’s 

iPhone (an accelerometer transforms the 

screen from portrait to landscape view when 

the user turns the phone sideways); microphones; 

televisions; laptop computers; GPS 

navigation systems; and Nintendo’s Wii. 

Experts predict MEMS applications will 

grow signifi cantly in the coming years. 

An industry analyst from Yole Développement 

SARL who spoke at a recent conference 

sponsored by the MEMS Industry Group 

projected that worldwide sales of MEMS devices 

would rise from $6.9 billion in 2009 to 

$13.2 billion in 2013. 

Before an uptick can occur, though, the 

companies that buy MEMS devices will need 

relief from current economic conditions. A 

representative from the market research fi rm 

Gartner Inc. told conference attendees that, 

in 2009, he expects revenues for the automotive 

and consumer product sectors—two 

major industries served by MEMS suppliers—to 

be down 30.1 percent and 19.9 percent, 

respectively. 

To fulfi ll its potential, the MEMS industry 

will also have to change some of the ways 

it conducts business and brings product to 

market. For one, it will need to improve design 

processes, which is the subject of this issue’s 

cover story. It will also have to develop 

mass-fabrication processes for MEMS. And, 

according to the Yole analyst, suppliers must 

decrease the time and expense of commercializing 

MEMS devices. On average, it takes 

4 years to bring a MEMS product to market—at 

a cost of $45 million. 

Th e ongoing “microsizing” of consumer 

products and medical devices will be a prime 

driver of MEMS growth. Maximizing profi tability 

will necessitate fi nding new applications 

for existing technologies. 

“We are experiencing a technology convergence 

in MEMS,” said MEMS Industry 

Group Managing Director Karen Lightman. 

“Sensors made for automobiles—extremely 

complex systems requiring the highest levels 

of safety and reliability—are being used for 

health-care devices, such as heart monitors, 

and 3-D motion tracking. MEMS-based energy 

harvesters (clean, renewable alternatives 

to batteries for powering small systems) are 

being utilized in consumer and industrial 

systems, and they may one day be used in 

more energy-effi cient, or even all-electric, 

automobiles.” 

Assuming that day comes, the general 

public may come to understand—and appreciate—the 

benefi ts of MEMS technology as 

much as I do. µ 

Publisher 

MICROmanufacturing 

Telephone: (847) 714-0173 

E-mail: dnelson@jwr.com

TECHnews 

Laser technique 

promises improved 

artifi cial implants 

Purdue University researchers are developing 

technologies to make artifi cial 

implants that can be manufactured 10 

times faster, last three times longer and 

cost less than those made with current 

technologies. 

Conventional manufacturing of orthopedic 

implants typically involves coating 

the surface of milled or molded titanium 

parts with a polymer material that adjoins 

the patient’s natural bone or tissue cells, 

said Dr. Yung Shin, professor of mechanical 

engineering and director of Purdue’s 

Center for Laser-Based Manufacturing. 

The polymer’s life expectancy of about 

10 years requires some patients to undergo 

several implant procedures during 

their lives. 

Shin and his team of researchers are 

working to improve implant longevity by 

using continuous fi ber lasers to melt and 

combine titanium and ceramic (trical- 


cium phosphate or hydroxyapatite) powders, 

which are then deposited in layers 

to form the implants. The highest proportion 

of TCP is present in the implant’s 

porous, outermost layer, which makes 

direct contact with the patient’s bones. 

“Titanium and other metals do not 

match either the stiffness or the nature of 

bones, so you have to coat it with something 

that does,” Shin said. “However, 

Purdue University 

Purdue researchers are using continuous fiber lasers to make hip implants via layer 

deposition of melted titanium and ceramic powders. 

if you deposit TCP on metal, you don’t 

want an abrupt change of materials because 

that causes differences in thermal 

expansion and chemical composition, 

which results in cracks. One way to correct 

this is to change the composition 

gradually, so you don’t have a sharp 

boundary.” 

Since TCP degrades at a much slower 

rate than polymer materials, Shin estimates 

the TCP-coated devices can last at 

least 30 years, or three times longer than 

current implants. 

The laser deposition process also enables 

the researchers to make custom 

parts with complex shapes. “Medical im- 

aging scans could just be sent to the laboratory, 

where the laser deposition would 

create the part from images,” Shin said. 

“Instead of taking 30 days like it does 

now, because you have to make a mold 

fi rst, we could do it in 3 days. You reduce 

both the cost and production time.” 

Though Shin and his team of researchers 

are still refi ning their laser-based 

technology, he said it should be ready for 

commercialization in 2 years. 

Researchers devise 

microreactor from 

fused silica 

Cornell University researchers used 

high-purity fused silica to fabricate a 

microreactor capable of withstanding 

temperatures of 1, 100° C. An initial application 

for the device, which has an area 

of less than 3 sq. cm, is detecting athletes’ 

use of performance-enhancing drugs. 

While such testing today is widely 

conducted with larger-scale technology, 

shrinking its size to microdimensions 

can cut testing time by three times (down 

to 10 minutes) and reduce the amount of 

chemical preparation needed for analysis, 

said Tom Brenna, Ph.D., a professor 

in Cornell’s Division of Nutritional Sciences, 

who coordinated the project. 

“Th e reactor that is currently used 

commercially is a fi xed ceramic tube 

with an internal diameter of 500μm and 

a length of about 12", ” Brenna said. To 

conduct steroid doping tests, the tube 

(containing steroid molecules) is placed 

in a 6"-long furnace, which subjects the 

steroid to temperatures of about 1,000° 

C. Th e combustion reaction prepares 

the steroids for stable isotope analysis, 

allowing testers to distinguish between 

naturally occurring and synthetic 

testosterone. 

As Brenna and his team of researchers 

set out to minimize the size of the 

microreactors to reduce cycle time, they 

realized the conventional ceramic composition 

wouldn’t work. “As we reduced 

dimensions, the materials and components 

we had available became very 

fragile and were not suited for routine 

use,” Brenna said. “Th at’s why we went

to microfabrication.” 

Th ey decided to make the microreactor 

from split, 1mm-thick wafers of 

high-purity fused silica, which can accommodate 

the required temperatures. 

“Fused silica is glass—silicon dioxide,” 

said Herbert J. Tobias, Ph.D., technical 

lead for microfabricating the device. 

“Usually glass is doped with materials 

that make its melting point low, so the 

more pure it is the higher temperature it 

can withstand.” 

Th e Cornell researchers designed 

each half of the wafer with an input 

channel leading to a series of high-temperature 

coiled channels (10μm wide), 

where combustion takes place, and an 

output channel. Th ey used photolithography 

to create a pattern for the reactor 

channels, which were wet-etched into 

the wafers. 

Th e researchers have successfully 

Cornell University 

Fabricated with high-purity fused silica, the 

microreactor is capable of withstanding 

temperatures of 1,100° C. 

tested the microreactor and are fi netuning 

the device to further reduce testing 

time. Th ey’re also talking with manufacturers 

interested in mass producing 

the device. 

“Th e big innovation for us was not 

simply designing it the way we did, 

because many people have made tortuous 

[channel] paths like we did for various 

applications,” Brenna said. “Th e key 

was to make it in a material that will 

happily withstand 1,000° C for an extended 

time. And this fused silica really 

does the job.” 

Mobile surface 

analysis system 

for micromachining 

Microdynamics Inc. recently added 

the μQC inspection microscope to its 

line of surface analysis products. 

Measuring 8.5" wide × 4.5" long × 

3.7" high, the 4.8-lb. device is a noncontact, 

vertical scanning interferometer 

adaptable to a variety of applications, 

including micromachining, said John 

Beardon, president and chief technical 

offi cer of Woodstock, Ga.-based 

Microdynamics. 

Parts to be measured are usually 


TECHnews 

placed inside stationary interferometer 

systems. But the mobile, computer-controlled 

μQC [Quality Control] is designed 

for added fl exibility. 

“Th e μQC can be mounted on an X, 

Y or Z axis, on translational stages, on a 

CMM or attached to a robot,” Beardon 

said. “It can be oriented in any three-dimensional 

space. Because of its unique 

counterbalance system, we can use it 

upside down or sideways. And with the 

borescope interferometer attachment, 

we can measure the wall surface roughness 

in a bore as small as 6mm in diameter 

and 50mm deep.” 

Th e modular μQC consists of an interferometer 

attached to a vertical scanning 

axis with 20mm of travel. Th e μQC 

houses the linear motor drive, the encoder, 

servo controller, camera and an 

USB interface. 

“We’ve built a shutter into the interferometer 

and that allows you to close 

off the reference surface, giving you a 

higher contrast image,” Beardon said. 

Th e μQC can present images in 2-D or 

3-D graphics, with magnifi cations of 2×, 

4×, 10×, 20× and 40×. 

“Th e μQC can resolve better than 

20nm and return data in roughly 30 to 

40 seconds,” Beardon said. “If you’re using 

a 4× interferometer module, that image 

is roughly 1.5mm wide × 1mm high.” 

Th e μQC is capable of analyzing 

the surfaces of large engine blocks and 

MEMs with equal ease. Th e device costs 

about $25,000. For more information, go 

to www.microdynamics.net. 


New green laser 

for miniature projectors 

In mid-2010, Tokyo-based QD Laser 

Inc. plans to commercialize a green laser 

for use in mobile projectors that can be 

mounted on mobile phones and laptop 

computers. 

Developed in collaboration with Prof. 

Yasuhiko Arakawa of the University of 

Tokyo’s Institute for Nano Quantum 

Information Electronics, the laser mea- 

sures 5.6mm in diameter and consumes 

little power, since it can operate at up to 

60°C without the need for cooling. 

According to QD Laser, its green laser 

is the world’s fi rst to incorporate 

quantum dot semiconductor crystals. 

Th e company grows the quantum 

dot crystals by directing atom beams 

of indium and arsenic onto a gallium 

arsenide substrate in a vacuum. 

After a two-dimensional InAs crystal 

forms on the substrate, strain en- 

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The µQC can be affixed 

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both low and high 

resolutions, presented 

in 2-D or 3-D graphics, 

with magnifications of 

2×, 4×, 10×, 20× and 

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TECHnews 

ergy from the lattice mismatch between InAs and GaAs 

causes tiny islands of 3-D crystals to form. Th e crystals, 

20nm in diameter and 5nm in height, are quantum dots. 

Key to the production of the green laser is the application of 

distributed feedback (DFB) laser technology, which is used in 

high-reliability optical 

communications 

to create a quantum 

dot semiconductor 

crystal laser 

with a wavelength 

of 1064nm. DFB lasers 

oscillate in a 

single mode as the 

active region of the 

QD Laser 

QD Laser Inc.’s quantum dot laser can be 

used in mobile projectors. 

semiconductor laser 

is structured using 

diff raction gratings, 

where only wave- 

lengths in the interval of the diff raction gratings are amplifi ed. 

Th e photon stream is subsequently fi ltered through a nonlinear 

crystal via a process called second-harmonic generation, 

which is a nonlinear optical procedure that transforms 

two photons into one—with twice the frequency and half the 

wavelength of the original photons. In the case of the green 

laser, the photons have a wavelength of 532nm. 

QD laser noted that the conversion of the 1064nm quantum 

dot laser from electricity to light is effi cient and results in 

reduced power consumption. 

Cimatron issues white paper 

on micromilling 

Cimatron Technologies Inc., a provider of integrated CAD/ 

CAM solutions for mold, tool and die makers as well as part 

manufacturers, has issued a white paper for moldmakers seeking 

practical tips to overcome the challenges of micromilling. 

“With submicron tolerances and tool tips that can hardly 

be seen by the naked eye, micromilling presents moldmakers 

with numerous challenges,” said the Novi, Mich.-based 

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company. 

The white paper, titled “Capitalizing on the Growing Demand 

for Micro-Milling,” offers tips to help moldmakers. 

Topics include: 

■ Micromilling machining requirements—machine geometry, 

machine construction, guide-way system, drive and motion 

technology, spindle, tool holder and spindle interface, CNC 

technology, auxiliary components, machine requirements. 

■ Micromilling CAD/CAM requirements—data translation, 

tight tolerances, machining strategies, tool motion, multi-axis. 

To download a copy of the white paper, visit: http://toolingtimes.com/MMGuide_Register.htm. 

µ 

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MICROmanufacturing? 

Fill out and return the card on page 9 or 43. 

Or, subcribe online at www.micromanufacturing.com 


MICROmachining 

Avoiding bad breaks when boring 


There’s a basic misconception about applying 

micro boring bars to fi nish small 

holes: the tools won’t work. 

“Yes, they will,” said Duane Drape, national 

sales manager for HORN USA Inc. Th e 

Franklin, Tenn., toolmaker off ers tools in its 

Supermini line as small as 0.17mm (0.0067") 

for boring a hole with a 0.2mm (0.0079") 

minimum bore diameter at a maximum 

DOC of 0.02mm (0.0008"). 

“Th e maximum DOC doesn’t necessarily 

mean you remove that much stock. It just 

1 2 

4 

HORN 

A microboring sequence (clockwise from upper 

left): HORN’s Supermini boring bars are for 

finishing holes with a minimum bore diameter 

down to 0.2mm. 

means that’s the maximum clearance of the 

tool,” Drape noted, adding that a larger DOC 

can be taken when boring various softer materials, 

including plastics, aluminum and even 

titanium. 

Th ese micro boring bars are typically for 

Swiss-style machines, where the tool remains 

stationary and the workpiece rotates, but 

they can also be applied as rotating tools in 

machining centers. Either way, the machine 

must be stable. 

Th e tools must also be positioned on cen- 

3 

terline. Setting a boring bar above centerline 

creates more cutting force and, therefore, 

puts more pressure on the delicate microtool, 

reducing tool life and potentially causing it 

to break. A tool set above centerline can also 

hinder chip evacuation. When set below centerline, 

the noncutting portion of the tool 

may rub, causing the tool to break. (See diagram 

on page 46.) 

HORN designs and grinds a micro boring 

tool’s primary and secondary relief angles 

based on it being on centerline. Th erefore, 

altering a tool’s centerline placement diminishes 

its eff ectiveness. “It completely changes 

how the tool was designed to be cutting,” 

Drape said. 

Th ese problems are also evident when a 

boring bar is positioned above or below centerline 

and then manually rotated down or 

up into the centerline position. As the fi gures 

on page 46 show, a boring tool with a positive 

chip rake cuts more effi ciently than one with 

a neutral rake. “It must be a very positive, 

free-cutting geometry,” Drape said, “which 

means the top rake angle will not be zero.” He 

added that a sharp cutting edge also provides 

free cutting because the tool experiences less 

pressure. However, a sharp edge is more susceptible 

to chipping when bouncing occurs. 

Fortunately, toolmakers generally design 

the holders that accept the boring bar, or insert, 

to automatically position the tool on centerline. 

“Our toolholder completely takes care 

of it, ” Drape said. “It’s built into the polygon 

shape of our clamp.” According to Drape, an 

insert that’s removed from a HORN holder 

and placed back in the holder will have less 

than a 5μm (0.0002") variation on centerline. 

If adjustments are needed for microhole applications, 

HORN off ers microadjustment 

cartridges to adjust the center height within 

tenths when a boring tool is running on the 

back tool block of a Swiss-style machine. 

When the tool is running in the main tool 

slide, the programmer can position the slide 

at any point to allow microadjustment of the 

centerline because the main tool slide moves 

up and down linearly unlike a turret, which rotates. 

Normally, this slide is used for OD work, 

but if the end user performs microboring, this

Prevent tool snapping through chip control 

EFFECTIVE CHIP EVACUATION is critical when boring 

microholes because chips clogging a bore can cause the tiny 

boring bars to snap. Pacifi c Precision Inc. experienced that 

when boring a 1mm-dia., 5mm-deep hole in a titanium part. 

The San Dimas, Calif., parts manufacturer produces medical 

and dental implants and performs general machining. 

Pacifi c Precision uses micro boring bars on its Citizen Swissstyle 

machines and previously applied fl ood coolant to clear 

chips. “We 

were breaking 

and snapping tools in 

small, deep bores because of 

The Utilis Multidec Microbore tool from 

Genevieve Swiss has a multifaceted neck to 

reduce vibration and is secured by hand with a finepitch 

threaded nut. 

slide allows him to position the tool closer to the part for a 

more stable application. 

Genevieve Swiss Industries Inc., Westfi eld, Mass., also offers 

a holder that automatically aligns a boring bar’s cutting 

edge on center, including its smallest one—a 0.42mm-dia. 

(0.016") tool for a 0.5mm (0.02") minimum bore diameter. 

Manufactured by Utilis, the 

Multidec Microbore boring 

bars from Genevieve 

Swiss have an angled back 

end that locates within 5μm 

(0.0002") against a positive 

location pin in the Microbore 

holder. A fi ne-pitch 

threaded and knurled nut 

Genevieve Swiss Industries Inc. 

A multifaceted neck helps 

prevent micro boring tools from 

chattering. 

Genevieve Swiss 

applies suffi cient force 

against the snap ring collar 

on the boring bar, and the 

system provides an axial and 

radial location repeatability of ±10μm (0.0004"), according to 

the company. 

“You don’t have to worry about snapping the microtool 

when tightening the nut, ” said Scott Laprade, marketing manager 

for Genevieve Swiss. “Finger tightening is all it requires.” 

To minimize harmful harmonic vibration, the Microbore 

tools have a multifaceted neck, where every facet is a different 

thickness. “Th at prevents the bar from chattering,” 

Laprade said. In addition to front boring tools, the line includes 

tools for back boring, drilling and boring, internal 

By Alan Richter, 

Senior Editor 

chip control,” said Jouni Levanen, the company’s plant manager. 

He added that vibration and the resulting chatter were also 

causing tool breakage. 

A boring bar no larger than 0.8mm is required for the 1mm 

hole to provide clearance for the chips and oil. “An oil-based 

coolant seems to work best with titanium,” Levanen said. “Also, 

we need to use oil because of the revolving bushings on the 

machines.” 

The company tried various boring tools and found that Utilis 

Multidec Microbore through-coolant tools from Genevieve 

Swiss Industries Inc. worked from the get-go. 

The machines can provide a through-coolant pressure 

up to 2,000 psi, but the typical range is from 800 to 1,200 

psi. “That’s effective for evacuating chips,” Levanen said. In 

addition, the boring bars’ multifaceted neck cut the chatter. “We 

have not had any vibration issues with Utilis.” 

—A. Richter 



Micro boring tools 

usually are used 

on Swiss-type 

machines. 



grooving, boring and undercutting, profi ling, chamfering 

and threading. 

Another critical boring bar geometry is the lead off the 

front cutting edge, which reduces cutting pressure. HORN 

provides an 8° lead to enable free cutting, Drape explained. A 

smaller angle, such as 5°, provides a slightly stronger cutting 

edge but also creates more pressure, whereas one that’s 15° 

provides freer cutting but exerts more pressure on the tool’s 

corner radius. 

Th e corner radius for HORN’s 0.17mm boring bar is 

0.02mm (0.0008"), which Drape called a true radius with a 

controllable dimension rather than a chamfer. To achieve the 

required surface requirements on that radius without having 

excessive peaks and valleys, Drape said micrograin carbide 

is required for the tool’s substrate, which isn’t coated for the 

company’s smallest boring bars. 

On the other hand, Genevieve Swiss typically off ers micro 

boring bars coated with Utilis’ HX coating, which is similar 

to titanium aluminum nitrite but in a submicron-layer form. 

“Because the coating layer is so thin, it doesn’t increase the 

corner radii on the tools,” Laprade said. He noted that 

uncoated tools are also available. 

Sometimes a boring tool begins its life coated and fi nishes 

it without one on the cutting edge. For instance, Doug 

Day, CNC specialist at Tomak Precision, Lebanon, Ohio, applies 

coated tools to bore stainless steel, cobalt and titanium, 

among other materials, and then manually regrinds them for 

an aluminum or brass job. “A coating is not necessary then,” 

continued on page 46

LASERpoints By Ronald D. Schaeffer, 

PhotoMachining Inc. 

Cost considerations when buying a laser 

Over the past few years, the federal government 

has off ered companies purchasing 

capital equipment some pretty good 

incentives—like accelerated depreciation. 

Now may be the time to buy that laser micromachining 

system you’ve always wanted! 

Before giving a thumbs up or down to acquiring 

a laser, though, there are some important 

cost factors to consider. Among 

them is operating cost. Th e informa- 

tion that follows will give you an idea 

of the annual costs of operating a laser. 

Capitalization. At minimum, a typical 

precision laser will cost $250,000 and may 

run over $500,000. Expect to pay, on average, 

about $350,000 for a good machine. Of 

course, much depends on the system chosen 

and its level of automation. 

In order to determine the average annual 

operating cost for a laser, let’s choose a 

$350,000 model. We will combine this fi gure 

with the expenditures discussed below. 

Facilities preparation. Th is cost can vary 

widely, depending on where in the facility you 

locate the laser. 

I know of one company that bought a laser 

and installed it in an area that experienced intense 

fl oor vibrations caused by a big motor 

running nearby. Instead of moving the laser, 

the owner tried to isolate it from the rest of 

the building. He removed a section of the existing 

fl oor, placed the laser in it and built a 

room around it. Th is cost tens of thousands 

of dollars, and the laser could not be used for 

several months. 

Local ordinances may also come into play. 

For instance, California has much more stringent 

requirements than good old “Live Free 

or Die” New Hampshire (where this writer 

lives). At minimum, there must be electrical 

preparations and, perhaps, some arrangements 

made for cooling water. 

Be prepared to address safety issues. Everyone 

thinks of eye safety when considering 

lasers, but there are other matters to think 

about. For instance, most lasers require a 

high-voltage power supply, which can be extremely 

dangerous for someone unfamiliar 

with using such equipment. Th ere also are 

material-handling issues and the need to remove 

debris, smoke and effl uent. Waste removal, 

depending on the type and how much 

is generated, can be a major issue. 

Here’s another consideration—one I always 

emphasize: If you want the laser tool 

to perform optimally, house it in a temperature- 

and humidity-controlled environment. 

Failure to do so is asking for trouble. Temperature 

and humidity can infl uence processing 

results. It’s also important to ensure the 

work environment is clean. It can cost lots of 

money to replace optics and other sensitive 

components damaged by dirt. 

Facility-preparation costs can run anywhere 

from $10,000 to $100,000. Let’s pick a 

conservative fi gure: $20,000. 

Operating expenses. Th ese normally include 

electricity, water, consumables (optics, 

fi lters, etc.), maintenance fees and service expenses 

for after-warranty work. Most laser 

micromachining work can be done with a 

sealed CO 2 , diode-pumped solid-state or 

fi ber laser. Operating expenses for these lasers 

are fairly low compared to excimer lasers, 

for instance. 


LASERpoints 

Th e hourly operating cost varies according 

to usage level. For example, the 

more the laser tool runs, the more electricity 

is consumed and the higher the 

utility cost. Some usage-related operating 

expenses are amortized over time, such 

as maintenance and refurbishment costs. 

Th e operating cost for a laser running 

one shift per day, 5 days a week, will 

probably be $20 to $30 per hour. If used 

more—i.e., to make more parts—the 

cost can drop to $10 per hour. (Note: 

Lasers can run about 20, 000 hours before 

they require major servicing.) 

Let’s fi gure operating costs at $10 

per hour and assume the laser runs 40 

hours per week. Th e yearly cost would 

be $20,800 ($400 × 52). 

Salaries. Th is expense also depends 

on the laser tool’s usage. At minimum, 

an engineer needs to oversee the laser, 

whether he runs it or not. An engineer 

typically is responsible for programming 

and maintenance, while an operator 

runs most of the jobs. 

Figure on minimal annual salaries of 

$50,000 for the engineer and $30,000 

for the operator. When you add insurance, 

taxes, benefi ts, supplies and so 

forth, the real costs for the engineer 

and operator are $65,000 and $38,000, 

Find It Online 

For advice on choosing a shop to perform 

laser work, read Ron’s column in the Fall 

issue of MICROmanufacturing or online 

at www.micromanufacturing.com (under 

“Articles”).—Ed. 




respectively. Add 30 percent to those 

numbers if your company is located in a 

major metropolitan area. 

Let’s assume the engineer devotes 

25 percent of his time to laser operations 

and the operator 80 percent. Th e 

costs would be $16,250 for the engineer 

($65,000 × 0.25) and $30,400 for the 

operator ($38,000 × 0.80), for a total of 

$46,650. 

If you want the laser 

tool to perform 

optimally, house it in 

a temperature- and 

humidity-controlled 

environment. 

To that amount, you need to add 

overhead and indirect expenditures 

such as managers’ salaries, common 

corporate areas and a host of other expenses. 

Th is fi gure varies from one 

company to the next, of course, but 50 

percent is a good rule of thumb. To fi nd 

the yearly labor expense for one-shift 

operation of a laser, multiply $46,650 × 

1.50, which comes to $69,975. 

If you amortize your capitalization 

and facility-preparation costs ($350,000 

+ $20,000 = $370,000) over a 5-year depreciation 

schedule, the cost per year is 

$74,000 ($370,000 ÷ 5). If you add salaries 

($69,975) and operating expenses 

($20,800), the total cost to own and operate 

a laser tool for a year is approximately 

$164,775 ($74,000 + $69,975 + 



$20,800). Th at breaks down to about 

$13,700 monthly. 

Worth the cost? 

If a company consistently needs laser 

work done in volume, it often will buy 

a machine. Th is is not always the case, 

though. Many large companies contract 

work to small laser shops. Th ey outsource 

the job because a smaller company 

often can perform the work more 

cheaply, due to having lower overhead 

and specialized expertise that would be 

expensive for a large company to acquire. 

Having said that, I know of many 

companies that must own a laser because 

their customers—usually in the 

defense sector—dictate that all processing 

be done in-house. In these cases, 

the numbers are skewed by the value of 

the total job. 

Another reason to acquire a laser 

tool is turnaround time. Quick-turn 

shops can charge higher prices, and 

they make bigger profi ts. 

Yet another reason to buy is if the user 

needs to integrate a laser into a production 

line so that a process can run uninterrupted 

from start to fi nish. 

In cases where there’s no requirement 

to buy a laser, however, the question 

usually comes down to, “Do I have 

enough business to warrant a monthly 

outlay of nearly $14,000?” µ 

About the author: Ron Schaeffer is CEO 

of PhotoMachining Inc., a high-precision 

laser job shop and systems integrator 

in Pelham, N.H. E-mail: rschaeffer@ 

photomachining.com. 

Subscribe 

now

Downsizing By Dennis Spaeth, 


Microturbines headed back to the future 

Nobody’s talking about generating 1.21 

gigawatts of power as was required in 

the “Back to the Future” movie, but microturbine 

research is headed back to where it 

was in early 2007. Dr. Alan Epstein, one of the 

prime movers behind the micro-engine project 

at the Massachusetts Institute of Technology, 

expected to have a micro-engine 

producing power by the late spring of that 

year, and a fully integrated device ready for 

commercialization within 5 years. 

In the interim, however, the research hit 

a wall at MIT and has moved to the University 

of Maryland in College Park, Md. Dr. 

Reza Ghodssi, a member of the MIT team 

from 1997 to 2000 and now the Herbert 

Rabin Distinguished Professor and Director 

of the Institute for Systems Research with the 

A. James Clark School of Engineering at the 

University of Maryland, continued to work 

on such a device—though with one major 

diff erence: Ghodssi is using stainless steel ball 

bearings to support the rotor as opposed to 

air bearings. 

And Ghodssi seems confi dent a fully integrated 

microturbine will be ready to demonstrate 

within 4 to 5 years. 

To truly appreciate this feat, we need to 

go back to 1995. Th at’s when it occurred to 

Epstein, now retired, that if a large turbine 

could power a city, then a tiny turbine should 

be able to supply enough electrical power 

for one person’s needs. It was, if you will, his 

“fl ux capacitor” moment. 

Main photo courtesy of Siemens AG; inset photos courtesy Reza Ghodssi, Matthew McCarthy, C. Mike Waits, Mustafa Beyaz, Brendan Hanrahan, University of Maryland 

In 1995, while pondering how a large turbine could power an entire city, such as the one above, produced by Siemens AG, Dr. Alan Epstein 

first thought about creating a microturbine to meet one person’s needs. A cross section of the microturbine (left inset) created at the 

University of Maryland reveals the location of the micro ball bearings, which are contained in a notch in the edge of the turbine below the 

rotors (right inset). 


Downsizing 

With a team of researchers, the professor 

in MIT’s Department of Aeronautics 

and Astronautics set out to 

develop a tiny turbine, which Epstein 

theorized could have a thrust-to-weight 

ratio of 100:1. Perhaps with his own 

nod to the “Back to the Future” movie 

franchise, he playfully observed in a 

May 23, 1997, issue of Science that it 

would be theoretically possible to use 

some 1,400 microturbines to levitate a 

skateboard. 

By early 2007, there were no levitating 

skateboards, but the MIT team had 

used silicon wafer technology to construct 

a prototype microturbine one 

layer at a time. 

“We showed that we could run this 

[device] at high temperatures,” said 

Stuart Jacobson, the former deputy 

director of the MIT micro-engine 

project. “We burned inside the combustion 

chamber, [and] the device sped 

up as you would expect when you’re 

putting a high-temperature gas through 

the turbine. And that basically showed 

the next step—that we could integrate 

the turbine machinery, the bearings 

and the combustion chamber in a 

single device. And that’s where things 

sort of closed out.” Funding from the 

U.S. Army Research Laboratory came 

to an end. 

While the team didn’t run into any 

“show stoppers,” noted Jacobson, the 

vital question that remained unanswered 

was whether the device could 

be manufactured at yield levels that 

would allow it to be sold at a reasonable 

price. 




Ghodssi credits the MIT project 

for sparking the creation of the annual 

Power MEMS Conference and generating 

a body of knowledge, technology 

and basic science that benefi ts similar 

research elsewhere—including his own. 

“When I went to Maryland,” Ghodssi 

recalled, “I realized that from my past 

work [at MIT and during his master’s 

research at the University of Wisconsin- 

Madison] that a lot of the diffi culties of 

developing the microturbine really lie 

in the complexity of the fabrication because 

the scales are so rigid. To meet 

the specs, you need a perfect fabrication 

process that by itself is very complex 

because you have multilayer fi lms 

coming together. 

“So I decided to take an in-between 

approach,” Ghodssi continued. 

“I thought about using stainless steel 

ball bearings on a small scale.” Th ough 

doing so produces a slower device, the 

simplicity appears to have paid off . In 

the University of Maryland MEMS Sensors 

and Actuators Lab, Ghodssi said 

the microturbine has reached speeds up 

to 95,000 rpm. 

“If you can reach 150,000 rpm,” he 

added, “you can start generating electricity.” 

And Ghodssi said he expects to 

do that very soon. 

Using 285μm-dia. stainless steel ball 

bearings eases fabrication because the 

spinning plates sit on ball bearings. 

“You don’t have to fi t them in place and 

hold them with pressurized air,” as with 

the MIT device, he noted. 

A critical breakthrough for the use of 

ball bearings, said Ghodssi, came from 



Dr. C. Mike Waits (currently at the 

Army Research Lab in Adelphi, Md.), 

who introduced the idea of supporting 

the microturbine with a planar-contact 

encapsulated ball bearing. 

With this encapsulated approach, 

the University of Maryland team no 

longer had to worry about handling 

the ball bearings one by one using tweezers. 

Ghodssi said encapsulating them 

made the fabrication process much 

more robust from a manufacturing 

standpoint. 

Ghodssi said he hopes to have a microgenerator 

ready to add to the microturbine 

within the next year. Th e goal in 

the next 2 to 3 years is to integrate the 

microgenerator with an off -the-shelf 

micro-engine. 

“So once the device is working,” observed 

Ghodssi, “it will be robust and 

reproducible.” 

And once that moment arrives, the 

microturbine could power anything 

from unmanned aerial vehicles to any 

number of digital devices used by U.S. 

troops, who could then do away with 

about 20 lbs. of lithium-ion and other 

batteries that they now must carry into 

battle. 

Asked whether the current microturbine 

device, which measures 23mm 

× 23mm × 1.5mm, could get smaller, 

Ghodssi noted that there are 150μmdia. 

ball bearings available. But fi rst he 

wants to prove the existing device can 

work. 

Now, if only we could hop in the 

DeLorean, we could fi nd out what 

happens! µ 

Subscribe 

now

MEASUREMENT matters By Susan Woods, 


Understanding scanning white 

light interferometry 

Scanning white light interferometry 

(SWLI) is a versatile technology 

that provides a noncontact, 3-D 

method of measuring surface roughness. 

Th e interference microscopy 

technology combines an interferometer 

and microscope into one instrument. 

Illumination from a white light 

beam passes through a fi lter and then a 

microscope objective lens to the sample 

surface. Th e objective lens is coupled 

with a beam splitter so some of 

the light is refl ected from a reference 

mirror. Th e light refl ecting back from 

the surface recombines with the reference 

beam. Th e recombined beams 

create bright and dark bands called 

“fringes,” which make up the interferogram. 

Fringes represent the object’s 

topography. 

Th e pattern of these fringes is captured 

on a CCD camera array for software 

analysis. By obtaining several 

frames of intensity information for 

each point, the system can recreate the 

sample surface. Th e frames are passed 

through an algorithm to convert those 

intensity signals into height information. 

Microscope-based white light optical 

profi lers are capable of measuring 

a variety of surface types, including 

ground and polished surfaces, steps 

and fi lms. Th ey do this by mapping 

surface heights that range from subnanometers 

to microns across areas 

that range from microns to millimeters 

in a single measurement. Th is rapidly 

provides surface roughness, shape and 

waviness data. 

When the required measurement 

areas are larger than the fi eld of view, a 

stitching procedure can be employed 

that involves a number of partially 

overlapping measurements being combined 

into one surface profi le. Stitching, 

however, requires that regions 

overlap, with the overlapping data 

aligning adjacent measurements. Be- 

cause overlap regions are measured 

more than once, overall measurement 

time increases. 

Th e primary applications for SWLI 

are surface measurement of MEMS 

(microelectromechanical systems) and

MEASUREMENT matters 

semiconductors. Other applications include 

measuring machined surfaces, 

microfl uidic devices, optics and fi bers, 

ceramics, glass, paper, thin fi lms and 

polymers. 

“Anywhere where it is important 

to understand vertical features over 

a small lateral scale is where it has a 

great application,” said Eric Felkel, product 

manager, Zygo Corp., Middlefi eld, 

Conn., a manufacturer of 3-D noncontact 

optical measuring instruments. 

SWLI optical profi lers are used in 

development and production environments. 

“It is an instrument that works 

well in the research lab, the failure analysis 

lab [and] in production manufacturing,” 

Felkel added. 

While other metrology solutions 

provide either high resolution or 

high speed, SWLI off ers both. It combines 

noncontact measurement, repeatable 

3-D surface measurement, high 

speeds and subnanometer resolution. 

SWLI is employed for surfaces with 

average roughness down to 0.1nm R a 

and peak-to-valley heights up to several 

millimeters, and repeatability can be 

0.1nm or better. (While the upper 

peak-to-valley height limit would most 

often be applicable to macro applications, 

it can be useful in certain micro 

applications.) 

Pros and cons 

SWLI off ers many advantages over 

other methods, such as stylus profi 

lometry and atomic force microscopy 

(AFM). Two principle advantages are 

SWLI’s high-speed and noncontact capabilities. 

Th e user can rapidly acquire a 

3-D rendered surface to make measurements 

immediately. 

On the other hand, “AFM is a very 

high-resolution technique, but it takes 

a lot of time to perform. It requires a 

very knowledgeable user,” said Patrick 

O’Hara, president and CEO of Ambios 

Technology Inc., Santa Cruz, Calif., 

a supplier of surface metrology 

instruments. 

And stylus profi lometry is a contact 

technique, which may not be desired. 

“When you drag a stylus across the sur- 


Zygo 

Shown measuring a MEMS device, the NewView 7300 white light optical profiler from Zygo 

characterizes and quantifies surface roughness, critical dimensions and other topographical 

features without sample preparation. 

Light source 

Filter 

Field of view multiplier (FOV) 

Aperture 

stop 

Field 

stop 

Interferometer objective 

(Mirau type) 

Reference mirror 

A schematic showing how SWLI works. 

face and it touches the part, it has the 

potential to damage or even destroy the 

surface you are interested in characterizing,” 

Felkel said. 

Another benefi t of SWLI is that it is 

an area-based technique, wherein the 

sensor images the interference signal 

from an area of the part and communicates 

that signal to the camera. Other 

Camera 

Beam 

splitter 

Translator 

Veeco Metrology 

topography techniques 

only sense the surface at 

a single point or along 

a single line. “You are 

looking at an area fi eld 

of view that is determined 

by the magnifi cation 

of the microscope 

objective being used,” 

Felkel said. “You can 

look at low-frequency 

structures, such as surface 

form, waviness 

and steps, with a lowmagnifi 

cation lens and 

then switch to higher 

magnifi cation and look 

at high-frequency features 

that contribute to 

roughness. Other ways 

of performing this type 

of surface characterization 

are not area-based, 

such as a triangulation sensor or a line 

scanner.” 

When compared to techniques such 

as video microscopy, SWLI is advantageous 

because it does not depend on 

part color to obtain high-quality data. 

Even if the surface being measured refl 

ects a small amount of light, that refl 

ected light interferes with the light

that refl ects off of the reference surface. 

Th is interference signal is what defi nes 

the surface measurement data. Because 

SWLI uses the interference signal to 

measure the height of the surface—and 

not simply a raw camera image like a 

video system—it is possible to measure 

structures that visibly have little color 

contrast, but are easy to see by their 

topography. 

Lastly, SWLI is an easy-to-learn technique 

and does not require sample 

preparation. “It is as simple as putting 

the sample under the microscope, focusing 

and measuring,” said Greg Maksinchuk, 

marketing product manager, 

Veeco Metrology Group, Tucson, Ariz., 

a provider of metrology and process 

equipment. 

Th e principle disadvantage of SWLI, 

or any optical technique, is that it depends 

on the optical properties of the 

medium through which it is looking, 

whether it’s glass, air or, for semiconductor 

manufacturing, thin fi lms. 

“Each of those dielectric thin fi lms 

has it own optical properties,” O’Hara 

said. “Th is can produce anomalous results, 

such as inaccurate fi lm thickness 

or step measurements, due to the diff erent 

optical properties of the fi lms. Most 

instrument manufacturers have proprietary 

methods of overcoming these 

anomalies, but the ambiguity remains. 

However, AFM or stylus profi lometry 

provides an unambiguous measure of 

the top surface or the step.” 

Also, SWLI is typically focused on 

the part’s vertical resolution, or topography, 

and less on lateral resolution, 

such as the part’s geometric dimensions. 

SWLI tools do focus on high 

lateral resolution, but if the user is primarily 

interested in lateral information, 

other less-expensive measurement 

methods are available. 

New developments 

While measuring thin fi lms can be 

a challenge, one of the most important 

improvements to SWLI technology is 

its ability to measure surface topography 

in the presence of an optical fi lm. 

“If the surface you are measuring has a 

transparent fi lm on it, you have two interference 

signals because you see the 

top and bottom of the fi lm,” Felkel said, 

adding that now SWLI can be used to 

measure the top and bottom of the fi lm 

and its thickness. 

And manufacturers are improving 

this process to work with thinner and 

Will your parts 

fit into this box? 

Parts that small need to be of the highest quality for reliability, 

yet they present significant challenges to achieving accurate 

3D measurements. We have solutions which can produce 

the results needed to minimize bottlenecks in your 

design chain and production processes, from our 

x-ray CT systems to our multisensor CMMs with 

nanometer accuracy all running CALYPSO 3D 

CAD-based metrology software. 

www.zeiss.com/imt 

Carl Zeiss 

IMT Corporation 

(800) 327-9735 

www.zeiss.com/imt 

thinner fi lms. “We work along two different 

paths,” Felkel said. “We develop 

software that can identify these interference 

signals as they get closer and 

closer together, and we design imaging 

systems to resolve these interference 

signals with higher fi delity.” 

continued on page 47 

Styli & Accessories 

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METROTOM 800 

O-INSPECT 


ABOUTtooling 

SCD tools: not just for specialized machines 


Single-crystal-diamond tools are routinely 

used to cut optical-quality components 

on special turning machines. But they also 

can run on conventional machine tools— 

often to great advantage. 

Th e main reasons are that many of today’s 

CNC machining centers and lathes incorporate 

ultraprecision ball bearing spindles, 

which couple with high-speed servodrives. 

And, control of axes motion has improved, 

thanks to linear motors and submicron-positioning 

feedback systems. Augmenting these 

improvements are ongoing CAD/CAM software 

developments that help the end user 

take full advantage of a machine’s enhanced 

capabilities. 

Cutting tools have evolved, too. Th ere are 

literally thousands of ways geometries, wearresistant 

coatings, substrates and other tool 

elements can be combined to optimize performance. 

Most of these tools eff ectively remove 

material, have acceptable wear life and 

meet the user’s surface-fi nish requirements. 

But there are applications where no other 

cutting tool material can duplicate the results 

achievable with single-crystal diamond. 

Like the name suggests, SCD is a solid 

crystal made from tightly packed carbon 

atoms. Using special equipment and techniques, 

SCDs are shaped into tools whose 

cutting edges have no apparent chips at mag- 

Single-crystal diamond vs. other cutting tool materials 

Surface fi nish Mirror fi nish: R a 

0.5µin. or better 

All images: Chardon Tool 

Prior to milling this copper, high-pressure manifold 

with a diamond-tipped carbide insert, shop 

personnel hand-lapped the sealing surfaces with 

a series of fine abrasives. One SCD tool can cut 

hundreds of parts, saving many hours of laborintensive 

processing. 

nifi cation up to 1,200× and exhibit extremely 

good wear resistance. Additionally, an SCD 

can be vacuum-brazed to almost any carbide 

insert. 

To use or not 

Choosing whether or not to apply SCD 

tools depends on a number of factors. Th e 

following questions and answers are intended 

SCD 1 PCD 2 PCD Coating WC 3 PCBN 4 

Depends on PCD 

grade: R a 2µin to 

32µin. 

R a 16 to 32 µin. R a 16 to 32 µin. Depends on PCBN 

grade: R a 1µin to 32 

µin. 

Accuracy Submicron 2µm to 5µm 2µm to 5µm 2µm to 10µm 2µm to 5µm 

Wear resistance 

(compared to WC) 

50× to 1000× 10× to 100× 5× to 50× 1× 10× to 50× 

Workpiece materials Aluminum, brass, 

bronze, copper, 

crystalline materials 

(including silicon, zinc 

selenide and germanium), 

graphite, metalmatrix 

composites, 

nickel and polymers 

Aluminum, brass, 


fi berboard, fi berglass, 

graphite, graphite 

composites, Kevlar, 

metal-matrix composites 

and polymers 

1 Single-crystal diamond. 2 Polycrystalline diamond. 3 Tungsten carbide. 4 Polycrystalline cubic boron nitride. 



graphite, graphite 

composites, metalmatrix 

composites, 

and polymers 


bronze, copper, cast 

iron, fi berboard, 

fi berglass, graphite, 

Kevlar, polymers, steel, 

titanium and wood 

Chilled cast iron, 

hardened tool and 

mold steels

to help you decide if an SCD tool is 

right for your application. 

When should I use SCD tools? 

When superior surface fi nish, part precision 

and long tool life are required. 

Depending on the machine tool, it’s 

possible to achieve a surface fi nish of 

R a 0.5μin. or better with an SCD. Th e 

structure of diamond is such that it can 

be sharpened to an almost perfect cutting 

edge. Th is unique property lets it 

produce mirror-like fi nishes. Diamond 

is also the hardest and most abrasionresistant 

substance known, allowing 

it to outlast carbide tools by 1,000:1 in 

certain applications. 

How do I know if my machine tool 

is rigid enough for SCD tools? Spindles 

should run quietly and be free from 

vibration. Slideways and lead screws 

must have minimal slop and backlash. 

Most modern CNC machines meet 

these requirements, making them suitable 

to run SCD tools. Styles are available 

for turning, facing, grooving, 

milling, spot facing, fl ycutting, boring 

and trepanning. 

What kind of materials can I ma- 

The shop that made this aluminum airframe 

casting was hand lapping the part’s difficultto-reach 

locating pads. Each surface had 

to be inspected. The company installed 

a diamond-tipped insert into its existing 

tooling and facemilled the part. This 

eliminated all hand work, and the process 

is now so repeatable that quality-control 

requirements are met with batch checks. 

chine? Just about any nonferrous 

metal—including aluminum, copper 

and brass—as well as plastics and many 

kinds of crystals. SCD is not suitable for 

By Hugh McAllister, 

Chardon Tool 

metals that contain iron. 

What kind of feeds and speeds 

should I use? In general, SCD tools are 

for fi ne fi nishing, so light cuts are the 



ABOUTtooling 

rule. Depths of cut range from 0.0001" to 0.001". Feed rates 

depend on the tool tip radius and desired surface fi nish. A 

good starting point for the feed is 0.400 ipm. Due to the cutting 

edge’s sharpness, cutting speed is not overly important. 

However, 1,000 sfm is a good initial speed. 

What about coolant? Users can opt for spray mist or 

microdrop lubrication. If fl ood coolant is used, it should 

be fi ne-fi ltered to remove swarf and fi nes that can become 

trapped between the cutting edge and workpiece surface. 

Th ese particles can chip the cutting edge or degrade the 

surface fi nish. 

Is an SCD tool expensive? Th e initial cost is signifi cantly 

higher than for a normal cutting tool. A typical diamondtipped 

insert sells for approximately $300. However, utilizing 

SCD tools can often eliminate costly, time-consuming lapping, 

polishing, honing and buffi ng of parts that have stringent 

requirements for 

geometric-form accuracy 

and surface fi nish. 

Moreover, SCD tools 

can be resharpened 

many times, and at a 

relatively low cost. 

What else do I need 

to know before cutting 

with SCD? Because of 

its extreme hardness, 

SCD is brittle. Care 

must be taken when 

handling tools. Don’t 

touch the cutting edge 

with fi ngers, dirty chip 

brushes or rags. When 

not in use, the tools 

should be kept in their 

protective packaging. 

Workholding and 

An end user was machining this 

housing for an underwater camera on 

a conventional CNC lathe. The domes 

were hand-polished to make them 

optically clear. The end user installed 

a diamond tool to make several fine 

finishing cuts, a move that eliminated 

the labor-intensive polishing process. 

toolholding devices should be rigid and tight. Vibration is one 

of the main causes of excessive SCD wear and poor cutting 

performance. 

When possible, use a noncontact tool-presetting system. If 

that’s not possible, place a plastic shim between the diamond 

and the surface of the preset device to avoid hard contact. 

SCD isn’t for everyone or every job, of course. Th e machine 

tool must be in good condition, the workpiece material 

must be of good quality and the operator needs to be 

trained on tool usage. But when mirror-like fi nishes and submicron 

accuracies are required, an SCD might be the tool to 

turn to. µ 

About the author: Hugh McAllister is sales engineer at Chardon 

(Ohio) Tool, a producer of diamond tools for ultraprecision 

machining applications. Telephone: (440) 286-6440. E-mail: 

hmcallister@chardontool.com. Web site: www.chardontool.com.

New Directions 

MEMS suppliers adopt new design strategies 

Cover Story 

Microelectromechanical systems are very 

small, which is one reason they’re a big 

challenge to design. Designers are meeting the 

challenge in a variety of ways, including application 

of new engineered materials, software tools 

and testing techniques. 

What’s more, designers are employing strategies 

to expedite the process of producing new 

MEMS devices, such as minimizing component 

By William Leventon 

interactions, making use of generic designs and 

modifying existing MEMS designs to improve 

manufacturability. 

Some MEMS designers are also benefi ting 

from a broader view of what can be a narrowly 

focused process. Th ese designers are paying attention 

to critical areas like assembly and packaging, 

as well as reaching out for important input 

from colleagues outside the design offi ce. 

Microvision Inc. 


New Directions continued 

Material advances 

Perhaps nothing affecting MEMS 

design is experiencing more rapid 

and profound change than materials. 

New engineered silicon-on-insulator 

materials include through-silicon vias 

(TSVs) to significantly reduce device 

footprints. TSVs connect to external 

devices via solder bumps, eliminating 

the need to make electrical connections 

with wires and bond pads that can clutter 

chips, explained David Buckley, vice 

president of sales and marketing for Micralyne 

Inc., a MEMS foundry in Edmonton, 

Alberta. 

Micralyne also works with proprietary 

engineered materials known as Glancing 

Angle Deposition fi lms. GLAD is a 

patented, thin-fi lm fabrication process 

developed by Micralyne and the GLAD 

Laboratory at the University of Alberta. 

GLAD diff ers from traditional thin fi lm 

deposition techniques by using highly 

oblique deposition angles that produce 

tilted-column nanostructures on substrates. 

By creating millions of these 

columns on a substrate, GLAD greatly 

increases the active surface area, making 

it more sensitive and, thereby, increasing 

its ability to detect various substances. 

Th is can be an advantage in life sciences 


and other applications, Buckley noted. 

MEMS material options have also expanded 

to include silicon carbide and 

diamond, which can withstand higher 

temperatures than regular silicon, according 

to Keith Ortiz, manager of MEMS 

technologies for Sandia National Laboratories 

in Albuquerque, N.M. Th is makes 

them suitable for devices such as sensors 

that measure temperatures in the hot 

compartments of jet engines. 

On the downside, Ortiz added, sili- 

HT Micro Analytical Inc. 

HT Micro impact switch device, a passive omnidirectional acceleration switch that measures 

2mm × 2mm × 1mm, was developed in conjunction with the U.S. Army for fuzing 

applications. 

No software task is more 

important to the MEMS 

design process than 

simulation. 

con carbide and diamond are less reactive 

than silicon, making them diffi cult to 

etch during a MEMS-fabrication process. 

As for metals, MEMS designers are 

moving away from traditional monolithic 

materials and toward alloys, noted Paul 

Rubel, vice president of design and product 

development for Innovative Micro 

Technology (IMT), which off ers contract 

MEMS manufacturing and design 

services in Santa Barbara, Calif. Unlike 

monolithic materials, gold, copper and 

nickel alloys off er long-term resistance 

to creep, as well as greater conductivity 

and hardness, added Rubel. 

At HT MicroAnalytical Inc., Albuquerque, 

an electrodeposition process is 

used to produce metal alloys for MEMS 

devices. Research has shown that electrodeposition 

can alter the microstructures 

of materials in order to change mechanical 

characteristics such as yield strength 

and fatigue resistance, said Todd Christenson, 

HT Micro’s vice president and 

chief technology offi cer. 

Christenson said that one metal alloy 

produced in this manner offers yield 

strength of more than 1GPa and can handle 

more than 10 million cycles at a stress 

of more than 1,000 MPa. HT Micro uses 

the alloy to make microminiature fl exures 

for impact switches. 

In addition to metals and silicon, 

MEMS designers are taking advantage of 

the special properties of polymers. For example, 

Rubel said designers are beginning 

to use polyimides for structural components 

of complex 3-D MEMS devices that 

would be more diffi cult to make using silicon 

or metal. In addition, he said, SU-8 is 

becoming more common in the fabrication 

of MEMS parts. Th is photo-imageable 

polymer becomes a hard, glass-like 

structure once cured, making it an eff ective 

structural material. 

Other polymers have what it takes to 

be good actuator materials. 

Electro-active polymers can undergo 

large amounts of deformation, making 

them suitable for artifi cial muscle actuators, 

according to Dan Popa, an assistant 

professor of electrical engineering at Th e 

University of Texas at Arlington. 

Another new actuator material is PZT, 

or lead zirconate titanate. A piezoelectric 

material, PZT changes shape when an external 

electric fi eld is applied. For microactuator 

use, PZT off ers high precision 

and force output but very small displacement, 

Popa said. It also allows conversion 

of displacement into voltage for energyharvesting 

applications. 

Software and MEMS design 

Like their counterparts in other fi elds, 

MEMS designers rely heavily on software 

for a variety of crucial tasks. Among 

other things, the latest MEMS software 

can help engineers optimize designs to 

achieve their goals. 

“If you have a device that heats something, 

[software] can help you fi gure out

where to place the heater to get maximum 

effi ciency,” said Mary Ann Maher, CEO 

of SoftMEMS LLC, a MEMS software 

developer in Santa Clara, Calif. 

No software task is more important to 

the MEMS design process than simulation, 

which is complicated by the fact that 

even relatively simple MEMS designs can 

involve a number of diff erent physical domains. 

MEMS designers deal with these 

situations by using so-called “multiphysics” 

simulation software from companies 

such as ANSYS, Comsol, Coventor and 

IntelliSense. 

SoftMEMS LLC 

MEMS Xplorer from SoftMEMS is said to 

have an intuitive user interface and provides 

MEMS-specific capabilities that reduce mask 

layout time. 

If you start by trying to 

do everything at once, 

you’ll get really confused, 

so start with a simple 

model. 

Even with this special software, however, 

it can be diffi cult to perform a multiphysics 

simulation. In some cases, “you 

would need a Cray computer to do all the 

calculations,” IMT’s Rubel said. To simplify 

the process, designers sometimes 

break up the job into smaller tasks. When 

designing some electromagnetic devices, 

for example, IMT does separate magnetic 

simulations and then inputs that data into 

actuator simulations. 

“If you start by trying to do everything 

at once, you’ll get really confused. 

Start with a simple model,” advised Micralynes’ 

Buckley, who defi nes a simple 

model as one that takes into account just 

one aspect of the design. MEMS devices 

are essentially “big mechanical structures 

made very small,” he added, so one way 

to start is by performing a relatively sim- 

ple mechanical analysis of the structure 

using fi nite element analysis (FEA). Th e 

mechanical analysis can be followed by 

separately modeling other physical aspects 

of the design. Finally, all the separate 

models can be combined into the 

multiphysics model. 

To simplify matters further, MEMS designers 

may choose not to start with FEA, 

which can involve complex meshing and 

yield detailed simulation results. Instead, 

University of Texas’ Popa said, designers 

can make “lumped model approximations” 

that don’t involve FEA. Lumped 

models break complex systems into discrete 

components and approximate the 

behavior of the components. Th ese approximations 

can then be tied together 

to show how the entire system will work. 

The important difference between 

lumped model approximations and FEA 

is the number of nodes in the models. 

For example, an FEA model of a cantilever 

might have 100 or even 1,000 nodes, 


New Directions continued 

Popa said. In such cases, “if you wanted 

to look at 1,000 cantilevers with FEA, it 

would be prohibitively complicated and 

time consuming.” By contrast, he noted, 

a lumped model can approximate a cantilever 

with just one node, greatly simplifying 

the task of studying the behavior of 

1,000 cantilevers at the same time. 

Physical testing 

Whatever method is employed, 

the key to a good simulation 

is using accurate material 

properties. But in many cases, 

obtaining these properties is not 

simply a matter of looking them 

up somewhere. 

“In the MEMS industry, there 

are a lot of thin fi lms and other 

materials being used that may 

not be well characterized,” Soft- 

MEMS’ Maher said. “So designers 

need good test structures to 

make sure they’re putting accurate 

material information into 

their simulations.” 

Test structures help designers evaluate 

both the structural behavior and the reliability 

of new materials. Th ese test structures 

are much simpler than the MEMS 

devices being designed. For example, 

Rubel said, a designer might make a cantilever 

beam out of a certain material and 

then subject it to electrostatic force to see 

how much the beam deforms. Creating a 

simple beam to obtain this information 

is much easier and faster than building a 

prototype of the entire device in order to 

run the test. 

Testing also can be the best way to ob- 


tain other types of information critical to 

MEMS design. Consider a designer who 

must determine the damping eff ects in 

an impact switch in order to produce a 

certain response time. One way to get the 

information is to use a computer simulation. 

But modeling an entire complex 

device structure “can take a long time,” 

Christenson said. 

So instead of going through a lengthy 

simulation process, he and his colleagues 

Micralyne Inc. 

Shown is a MEMS optical mirror produced by Micralyne using 

Micragem, which is a four-mask lithography MEMS process. The 

starting point is a 500µm-thick glass wafer. 

at HT Micro create cells where they use 

tests to obtain empirical information 

about damping behavior. If the fabrication 

process is relatively short and simple, test 

cells can yield key design data faster than 

simulation, he said. 



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page 9 or 43. 

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In addition to proximity 

effects, the MEMS 

designer may fail to 

account for the impact of 

assembly and packaging. 

Similarly, Micralyne uses simple “short 

loop” experiments to help eliminate 

uncertainties. For example, suppose a 

MEMS design calls for an embedded 

structure 1.5μm wide, with an accuracy 

of ±50nm. To see if this design is manufacturable, 

Buckley said, “you can run the 

full fab process, which may take 8 weeks. 

Or you can just do one layer to see if you 

can hit those tolerances, which may take 

2 days and allows you to provide rapid 

feedback to the designer.” 

Simplifying the process 

Just as MEMS devices can be 

complex, so can the processes 

used to design and manufacture 

them. But there are steps 

designers can take to simplify 

these processes, thereby saving 

time and money—not to 

mention trouble. For instance, 

they can minimize or eliminate 

component interactions such as 

pneumatic cross-talk so that the 

components can be considered 

independent of each other, which simplifi 

es design. 

At IMT, complications result when 

customers insist on the use of materials 

and processes that are unfamiliar to 

the company. Th ese customers would be 

better off opting for one of IMT’s many 

“platforms,” which are generic or base 

MEMS designs, suggested Rubel. “Even 

though we may not have designed a particular 

product for a customer before, we 

can use one of our platforms as a basis 

for creating the product, taking a general 

architecture and adapting it to what 

the customer wants,” he said. “To adapt 

Subscribe 

now

The tiny swimmer 

A “MICROSWIMMER” RESEMBLING a tiny fi sh was this year’s 

winner in the novel design category of the 5th annual MEMS 

University Alliance Design Competition, sponsored by Sandia 

National Laboratories. About the diameter of a human hair, the 

microswimmer has an aluminum tail that moves back and forth 

when heated and cooled by bursts of microwave radiation. 

In the future, a medical device like the microswimmer could 

be used to travel in the human bloodstream, according to Tom 

Zipperian, Sandia senior microfabrication manager. 

The novel design category is for innovative designs that take 

advantage of the strengths of the Sandia Ultra-planar Multi-level 

MEMS Technology 5 (SUMMiT V) fabrication process, which 

that platform makes the design simpler, 

increases the probability of success and 

signifi cantly reduces costs.” 

By choosing a platform, MEMS designers 

also can make their devices easier 

to fabricate, because platforms are based 

on products that have already been successfully 

manufactured. Th is allows IMT 

to take advantage of previously acquired 

manufacturing knowledge, Rubel noted. 

A broader view 

MEMS devices are aff ected by many 

external factors, both in production and 

in use, so designers must be sure not to 

focus on a device operating in isolation. 

Such an approach fails to account for factors 

like electrostatic eff ects or energy 

loss, which can be caused by wiring or 

other devices that are in close proximity 

to a MEMS device. 

Designers “have to simulate the environment 

of the device in addition to the 

device itself,” Maher said, adding that 

new software tools allow designers to 

evaluate so-called “proximity eff ects” on 

MEMS devices. 

In addition to proximity eff ects, the 

MEMS designer may fail to account for 

the impact of assembly and packaging. 

According to some estimates, assembly 

and packaging can account for up to 90 

percent of the cost of a MEMS device. 

Th ey also can have a signifi cant eff ect on 

the behavior of a device. “You may have 

a product that works great when it’s not 

packaged, but won’t work when it is packaged,” 

Popa said. 

Still, he added, the traditional approach 

is to deal with assembly and packaging 

after the prototype is created. But he said 

these two processes should be considered 

early in the design phase. 

New software can help designers do 

just that. In the past, separate software 

tools were used to design the MEMS device, 

the device packaging and the accompanying 

electronics. While this allowed 

designers to optimize their particular 

parts of the system, “they couldn’t really 

see how to optimize the whole system,” 

Maher said. 

So SoftMEMS developed software that 

brings simulation up to the system level, 

linking FEA with electronics and packaging 

design. Th is allows people in diff erent 

areas to work together on a co-design, 

which can reduce design time and overall 

system costs, Maher said. 

Collaborative software tools may be 

helpful, but they can’t take the place of 

an old-fashioned meeting, according to 

one industry observer. 

“Early in the design process, it’s imperative 

that you bring the whole team together,” 

said Roger Grace, a Florida-based 

MEMS marketing consultant. In addition 

to the designers, the MEMS team 

includes those responsible for packaging, 

testing and manufacturing the device. 

During the meeting, all the attendees 

should provide their own special design 

input. For example, Grace said, “the 

testing people might tell the designers, 

‘If we’re going to test this thing, we need 

these kinds of pads on these devices.’ Or 

the packaging people might provide practical 

footprints for the design.” 

Of course, communication should be a 

continuing process throughout the design 

phase. But according to Grace, “the kickoff 

meeting is important, so everybody is 

on notice at the outset that this project is 

a team eff ort.” µ 

manufactures MEMS devices with fi ve levels of polysilicon. 

SUMMiT V was used to make parts for the contest entrants. 

Sandia’s MEMS experts and university professors reviewed the 

designs and picked the winner. 

Contestants must come from schools that are members 

of the MEMS University Alliance, which is open to all U.S. 

institutions of higher learning. The alliance provides classroom 

teaching materials and reasonably priced licenses for the use of 

Sandia’s SUMMiT V tools. This makes it possible for universities 

lacking their own microfabrication facilities to offer a MEMS 

curriculum. 

—W. Leventon 

Contributors 

Roger Grace Associates 

(239) 596-8738 

www.rgrace.com 

HT MicroAnalytical Inc. 

(505) 341-0466 

www.htmicro.com 

Innovative Micro Technology (IMT) 

(805) 681-2800 

www.imtmems.com 

Micralyne Inc. 

(780) 431-4400 

www.micralyne.com 

Sandia National Laboratories 

(505) 845-0011 

www.sandia.gov 

SoftMEMS LLC 

(408) 426-4301 

www.softmems.com 

University of Texas, Arlington 

Automation & Robotics 

Research Institute 

(817) 272-5900 

www.arri.uta.edu 

About the author: 

William Leventon is 

a New Jersey-based 

freelance writer. 

Telephone: (609) 

926-6447. E-mail: 

wleventon@verizon.net. 


Taking Form 

Electroforming use grows as complex electronic devices shrink 


By Lowell Thomas and Luke Volpe, Dynamics Research Corp., Metrigraphics Division 

As the drive to build smaller and more complex 

electromechanical devices (microdevices) 

continues, design engineers struggle 

to bridge the gap between traditional micromachining 

techniques, such as milling, laser 

cutting and EDMing, and MEMS (microelectromechanical 

systems) technology. 

Specifi cally, design engineers are discovering 

that many products now in the design stage 

are too small to be machined with traditional 

All images provided by Metrigraphics 

Four-layer micro induction coil with 12.5µm lines 

and spaces, 7µm-thick gold traces and 10µm-thick 

polyimide dielectric between traces. 

techniques and are not candidates for MEMS 

technology because of size, cost or material 

limitations. 

A combination of two mature technologies—electrochemical 

metal deposition and 

micron-level photolithography—have enabled 

the manufacture of 3-D microstructures that 

bridge the gap between traditional machining 

techniques and MEMS technology. 

Th e term “electroforming,” as used in this article, 

refers to the electrochemical deposition of 

a variety of conductive metals, including gold, 

copper, nickel and nickel/cobalt, into a prefabricated 

mold, usually an ultraviolet-imagable 

photoresist. Th e technology forms freestanding 

or linked multilevel microstructures, sometimes 

referred to as 3-D micros, with microsized 

features. 

With its ability to create ultrafi ne features, 

electroforming has replaced EDMing and conventional 

machining in some applications. However, 

the strength of this new technology is not 

in replacing other techniques but in enabling 

new part designs. 

Th is article discusses electroforming technology 

and limitations, specifi c application areas 

and development trends. 

Technology’s foundation 

As stated, electroforming creates 3-D structures 

by electrochemically depositing a metal 

into a photoresist mold. Basic process steps are 

as follows (see illustration on page 32): 

1. A carrier plate is prepared by sputter 

depositing a thin (less than 5,000 angstroms) 

adhesive/conductive seed metal 

layer onto a glass blank, or other suitable 

base material. 

2. A photoresist mold of the intended structure 

is created. Th e mold is formed by depositing 

and imaging the X- and Y-plane 

features of the intended structure into 

a UV-sensitive photoresist on the seed 

metal coated glass carrier. 

3. Th e desired metal is electrochemically 

deposited into the photoresist mold prepared 

in step 2 above. 

4. Th e photoresist mold is removed from 

the glass carrier plate. 

5. Finally, the completed electroformed 

microstructure is removed from the carrier 

plate. 

Multilayer structures are formed by repeating 

the above steps. Th is process is capable of creating 

3-D microstructures with features—posts, 

channels and grooves—as small as 0.005mm. 

Funnel-shaped through-holes as small as 

0.001mm in diameter are possible. 

Th e X- and Y-plane dimensions are controlled 

by the photoresist process. Th e Z-axis dimensions, 

such as post and wall heights, channel 

depths and wall profi les, are controlled and 

restricted by the photoresist aspect ratio. Th e

aspect ratio is equal to the maximum 

height (Z dimension) divided by the minimum 

feature width (X or Y dimension). 

For example, a 0.010mm-dia. × 

0.030mm-high post would have an aspect 

ratio of 3:1. Maximum X and Y dimensions 

can be 25mm, and generally are 

less than 1mm or 2mm. 

Th e current generation of 3-D microstructures 

made by microforming fall into 

the dimensional realm described above 

and are used for a variety of applications, 

including medical devices, magnetic induction 

coils for RF coupling, data transfer, 

microfl uidic molds and integrated 

circuit manufacturing. 

To date, electroforming has been successfully 

implemented in many applications, 

enabling the development of 

diverse structures not possible with other 

micromanufacturing technologies. (See 

Figures 1, 2 and 3 for examples of electroformed 

devices and features.) 

However, current electroforming technology 

faces challenges in terms of minimum 

structure size, maximum structural 

aspect ratio, number of possible layers, 

fl exibility issues related to multilayer devices 

and manufacturing cost. Future 

applications could also require dielectric 

coatings or interlayers not currently available. 

(Note: Dielectric isolation has always 

been required for 3-D microstructures 

used in electrical applications. Current 

challenges in applying dielectric coatings 

on microstructures include coating uniformity 

and the inability to coat the structure’s 

carrier side. As structures become 

smaller, it will be essential to uniformly 

overcoat the entire 3-D structure.) 

Photoresist 

Several photoresist materials exist that 

are capable of resolving 0.010mm structural 

features with aspect ratios of 3:1 (5:1 

aspect ratio structures are possible with 

some restrictions). Photoresist materials 

that allow higher aspect ratios for smaller 

feature sizes could improve the functionality 

of existing devices and enable new 

applications. 

Figure 1: RF coupling device. Figure 2: Funnel-shaped orifice hole. 

Future device-design engineers will 

be looking to build structures with minimum 

feature sizes in the 0.002mm to 

0.005mm range with 5:1 to 10:1 aspect 

ratios. 

Once the electroformed metal deposition 

has been completed, the photoresist 

mold must be chemically removed, 

a process known as stripping, or dissolving. 

Removability has a signifi cant eff ect 


Taking Form continued 

on minimum aperture, or blind-hole size, 

as well as on isolated cavities in multilevel 

structures. As blind-holes and isolated 

cavities become smaller, the ability 

of solvent chemistry to penetrate holes 

and cavities becomes an issue. 

Some photoresists are available that 

can resolve higher aspect ratios, but, to 

date, these materials are limited by solubility 

characteristics, or stripping issues. 

However, most manufacturers of photoresists 

are developing solutions to these 

challenges. 

Imaging method 

Th e imaging method (UV) also has a 

signifi cant eff ect on aspect ratio and feature 

characteristics, such as wall angle 

and uniformity. Th ere are two traditional 

imaging methods. 

Th e predominant method is contact 

printing. With this approach, a photographic 

mask containing multiple, reverse-polarity 

images of the structure to 

be built is placed in intimate contact with 

the photoresist-coated carrier plate. Th e 

carrier plate/photoresist/mask stack is 

exposed to a collimated UV light source. 

Depending on the type of resist used, the 

UV-exposed photoresist will either be 

cross linked or made soluble so the retained 

photoresist will form the desired 

mold cavity. 

Th is system is economical, relatively 

easy to use and can create a full sheet of 

hundreds—possibly thousands—of mold 

cavities with a single exposure. However, 

UV intensity variation over the mask area 

and defects caused by mask contact with 

the photoresist can reduce product yield. 

Th e second method is projection-imaging 

stepping (repeating). Devices made 

with this method are used extensively 

in the integrated-circuit and fl at-panel 

display industries. Th ese systems use 

a single-structure image mask at some 

magnifi cation that is projected through 

a reduction lens onto and into the photoresist 

plane (base carrier plate coated 

with photoresist). 

Th e UV source is positioned behind 

the single-image mask with a shutter 

mechanism between them. Every time 

the shutter opens, a single unit structure 

is exposed. When the shutter is closed, an 

interferometer-controlled, movable stage 

repositions the base carrier plate. 


2.a 

2.b 

2.c 

Second-level mask 

2.d 

Second-level 

photoresist mold 

2.e 

2.f 

Precision electroforming process 

Glass Carrier 

Th e advantages of this system are that 

higher-resolution, concentrated UV 

power permits deeper exposure, result- 

Unexposed photoresist 

Seed metal 

UV expose First-level photo mask 

Imaged photoresist 


First-level 

electroplated metal 



Seed metal 

Second-level seed metal 

Photoresist mold 

UV expose Second-level imaged 

photoresist 

Second-level seed metal 

Second-level electroplated metal 



Completed second-level electroformed microstucture 

before being removed from glass carrier 

Figure 3: Monofilament/microlens holder. 

ing in a higher aspect-ratio capability 

and greater image-to-image consistency 

for UV exposures. Th e system is also

The quest for smaller microelectronic devices 

ONE OF THE CRITICAL ISSUES in the 

quest for smaller, more complex medical 

and telecommunication devices is the 

integrated circuit chip interconnect system. 

Because of size, biocompatibility and 

fl exibility requirements, traditional 

fl ex circuit and PC board technologies 

are typically not suitable for these devices. 

The current generation of 

medically implantable telemetric and 

telecommunication microdevices 

are based on extreme-resolution, 

microfl exible-interconnect (ERMF) 

circuits. This technology depends on 

microphotolithography, thin-fi lm sputterdeposited 

base metals, electrochemically 

deposited metal (usually noble) traces, 

biocompatible polyimide substrates and 

dielectric interlayers. 

Minimum signal trace and space 

dimensions are 3µm to 5µm. For 

applications requiring signifi cant current 

density, high-aspect ratio trace cross 

sections allow higher current-carrying 

capacity and minimize overall circuit area. 

ERMF circuits may have a single 

conductor level or as many as six 

conductor levels, depending on device 

complexity. 

To date, ERMF circuits have been 

successfully used in several intrusive 

and implantable medical applications, 

such as ultrasonic angioplasty probes, 

blood glucose monitoring systems and 

developmental retinal implants. 

Other, more complex ERMF circuitbased 

medical devices are being 

developed, such as permanently 

implanted RF coupling (data transfer) 

monitoring systems and more complex 

cardiac monitoring probes. 

The success of these and other 

still unidentifi ed medical and 

telecommunication applications may 

depend on yet unresolved or identifi ed 

ERMF manufacturing issues. These issues 

relate to materials and manufacturing 

technology. 

Liquid-state polyimide is generally 

considered the material of choice for 

ERMF circuits. This material, when 

cast and completely cured, typically 

has adequate dielectric strength in 

thicknesses above 0.015mm. As the 

circuits become more complex and 

require more trace layers, the fl exibility 

of the stack can become an issue. One 

possible solution includes improving the 

intrinsic dielectric properties of the cured 

polyimide, allowing for thinner dielectric 

interlayers. Thinner dielectric layers 

will improve the fl exibility of the cured 

material. 

One method of manufacturing utilizes 

UV photo-imagable polyimide to create 

via holes. This process can create an 

entire sheet of hundreds, possibly 

thousands, of holes with a one-photo 

process. Using this process, however, 

imaged via hole wall angles may be 

diffi cult to control and the process can 

produce random, poor or nonexistent 

continuity interlayer interconnects. 

Current ERMF manufacturing processes 

specify laser drilling to create via holes. 

This process creates clean, slag-free holes 

as small as 0.015mm in diameter with 

cured and planarized deposited polyimide 

predrilling. Laser-drilled holes also have 

positively tapered wall angles that ensure 

complete metal coverage and reliable 

continuity. However, this process may not 

be cost effective without semi-automated 

or fully automated equipment. 

Investments in manufacturing 

development are being evaluated that 

could help ERMF technology reach its 

full potential. The following issues are 

currently under evaluation: 

■ The standard 6-sq.-in. panel size 

restricts high-volume production; 12-sq.in. 

or round panels will be required. 

■ Chemical mechanical planarization 

will be required to guarantee fl atness 

and planarity on each layer of multilayer 

structures. This process is only suitable 

with laser via drilling. 

■ I/O bonding pads must 

accommodate processes such as pickand-place 

assembly and fl ip chip/solder 

refl ow. 

■ The circuit-manufacturing process 

must be automated to reduce the cost 

per circuit for high-volume manufacturing 

operations. 

— L. Thomas and L. Volpe 


Taking Form continued from page 32 

suitable for high-volume manufacturing. 

Its main disadvantage is that it requires 

a major capital investment. State-of-theart 

projection steppers cost $1 million 

and up, but some used equipment may 

be available now, or in the future, at signifi 

cantly lower cost. 

Any discussion relating to high-aspect-ratio 

imaging systems would be incomplete 

without mention of LIGA, a 

process named for the German acronym 

for lithographie, galvanoformung and abformung 

(lithography, electroplating and 

molding). LIGA is based on synchrotron, 

hard X-ray exposure of polymethyl methacrylate 

(PMMA). Although this system 

can resolve extremely high-aspect-ratio 

images (50:1 and greater), there are a limited 

number of synchrotron beam lines 

available and these are extremely costly 

to operate. (Synchrotron radiation is 

electromagnetic radiation accelerated to 

speeds approaching that of light.) 

Such systems cost hundreds of millions 

of dollars, depending on the total 

size and number of beam lines. Th ere are 

only four synchrotrons in the U.S., and 

they are all associated with large institutions, 

such as national laboratories and 

large universities. 

On a more practical level, continuing 

laboratory testing of newly developed 

photoresist materials will enable higher 

aspect ratios using more conventional exposure 

and developing techniques. 

Multilevel stacking 

Based on recent trends, future 3-D 

microstructures will become more complex, 

requiring multilayer structures. Th e 

current multilevel stack limit is between 

three and fi ve levels, depending on the 

criticality of individual stack thickness 

and fl atness specifi cations, minimum 

feature size and aspect ratio. (See Figures 

4 and 5 for examples of multilayer 

structures.) 

Th e critical issues in the stacking process 

are previous-layer uniformity, photoresist 

coating uniformity and precision 

of mask alignment to the previously electroformed 

layer. 

Plating uniformity is a key part of this 

process. Plating uniformity is a function 

of the anode and cathode positional relationship 

(in this system, the cathode is 

the sheet of 3-D structures being built) 


Figure 4: Two-level, magnetically activated switching device. The cross-section of the three 

serpentine springs is 0.050mm × 0.050 mm. 

Figure 5: Positive-locking, two-level contact interconnect. 

Figure 6: Two-level solid gold implantable 

capillary device. 

and current density uniformity. 

Th e geometry of the structure being 

plated determines current density uniformity. 

Practically all 3-D microstructures 

have varying geometric (X- and 

Y-plane) shapes and sizes. Th is X- and 

Y-plane variation is unique to each particular 

microstructure pattern. 

Unfortunately, one of the 

significant causes of nonuniform 

plating is pattern 

geometry variation. All microstructure-plating 

layers and 

thicknesses have some nonuniformity, 

the overriding 

multiple-level structure limitation. 

Nonuniform electrodeposited 

thicknesses cause 

imprecise alignment, and 

nonuniform plating in subsequent 

layers exaggerates 

the problem. As the number 

of required structural layers 

increases, structural geometries 

become distorted and 

overall thickness tolerances cannot be 

maintained. 

A planarizing technology called chemical 

mechanical planarization (CMP) 

combines chemical etching and abrasive 

polishing. It allows dissimilar materials, 

such as an electrochemically deposited 

metal and photoresist, to be planarized, 

or polished, to microfl atness. Th is planarization 

process addresses the multilevel 

limiting issues stated above. CMP is 

a mature technology but is used sparingly 

in multilevel microstructure manufacturing 

because of cost. 

As the demand for higher volume 

and more complex multilevel devices increases, 

chemical mechanical planarization 

will be required. In-house CMP 


ICOMM 

5 th INTERNATIONAL CONFERENCE ON 

2010 

MICROMANUFACTURING

Clean Machining 

Clean room use growing to optimize specialized processes 


By Joel Cassola 

Clean Air Products 

Various types of clean rooms are available, including soft-sided, hard-walled and modular styles. Shown is the Series 591 portable clean 

room from Clean Air Products. The free-standing, modular, prefabricated clean rooms are available from Class 100,000 to Class 10 and 

feature open spans from 6’ to 34’. 

With increasing frequency, access to controlled 

environments for attenuating 

temperature, humidity, dust, dirt, particulates 

and microorganisms is essential for shops competing 

for high-end micromanufacturing jobs. 

Historically, clean rooms were used primarily for 

cleaning, assembly and packaging operations. 

Today, they are also being used to control potential 

contamination and improve accuracy within 

molding, machining and inspection operations. 

Th e following “crash course” on clean rooms 

is based on interviews with two clean room suppliers 

and three micromanufacturers that have 

installed them. 

When and why are clean rooms used for 

micromachining? Th e naïveté of this question 

made some of our respondents laugh. Clean 

rooms are typically used to keep the controlled 

environments cleaner than surrounding areas, 

and temperature and humidity within acceptable 

ranges. Th e room or enclosure may protect parts 

from the incursion of dust being blown from 

other parts with an air hose at nearby machining 

operations. As a result, most clean rooms 

are under positive pressure. 

However, the question is actually not as naïve 

as it sounds, because sometimes clean rooms 

and equipment enclosures are designed to keep

things in—such as dust from exotic work 

materials, chemical fumes and the like. 

Th ese rooms rely on negative pressure. 

Ambient temperature may be controlled 

because it aff ects dimensional control 

of molded and machined parts. For 

example, a 7° C shift in temperature can 

cause a tool to grow or shrink by 0.01mm. 

Th at’s not much by conventional standards 

but poses real problems for parts 

manufactured to micron tolerances. 

Humidity can promote bacterial 

growth, cause parts to corrode or impede 

subsequent bonding operations. 

One manufacturer interviewed strives 

to control humidity around his milling 

equipment to within 10 to 15 percent and 

may even put off some sensitive manufacturing 

operations during hot and humid 

summer days. 

Some clean rooms control electrostatic 

discharge, which can zap electronics by 

overloading tiny circuits with heavy transient 

charges, burning them out. 

Th e driver behind all of these considerations 

is the need to meet increasingly 

stringent cleanliness and precision requirements 

for a growing list of industries. 

All of the respondents agreed that 

most OEMs producing pristine or sterile 

products demand exceptionally clean 

parts, even though these OEMs may be 

cleaning, assembling, fi lling and packaging 

the end product in their own clean 

room. Th ey appreciate, if not insist on, 

their suppliers having clean rooms so 

they don’t have to be as concerned about 

extraneous contamination entering their 

own processes. 

What types of manufacturers require 

clean rooms? Our respondents 

were happy to inform us that clean 

rooms are a growth business. Medical 

device, electronics, defense and aerospace 

component manufacturers are all 

big users. Th e trend toward marrying a 

wide range of electromechanical devices 

(for instance, tiny windshield wiper motors) 

with computer chips is currently 

driving a lively interest in clean rooms for 

both parts manufacturing and assembly 

operations to ensure that the electronics 

are not compromised by the incursion 

of particles created during conventional 

manufacturing. 

Can clean rooms make a contribution 

to micromachining operations? 

Defi nitely. For example, the need to con- 

Keeping clean 

THE PART MANUFACTURERS interviewed 

for this article offered the following 

perspectives on keeping their operations 

clean and under control. 

Made in a Class 10,000 clean 

room. Albright Technologies, Leominster, 

Mass., built a Class 10,000 clean room 

primarily to control particulates and 

temperature during proprietary silicone 

molding and inspection processes for 

implantable microscale drug-delivery 

devices. A half-million devices can be 

manufactured from just one pound of 

material. 

David Comeau, Albright’s president, 

said designing and building his fi xedwall 

clean room cost about $150,000. 

The company decided to build the 

Class 10,000 clean room instead of 

a Class 100,000 room, which would 

have been adequate, because the cost 

difference was not substantial. While the 

company was designing and installing 

its clean room, it also obtained ISO 

13485 certifi cation for medical device 


Micromachining in clean rooms. 

ARC Technologies, White Bear Lake, 

Minn., machines microparts for the 

aerospace and scientifi c instruments 

industries in a class 10,000 clean room. 

Advanced Research Corp. Vice 

trol thermal growth of the part or tooling 

is a critical factor when microparts 

have dimensions that must be held within 

microns. MicroEDMs and conventional 

machine tools may have special enclosures 

that do a good job of controlling 

President Marlow Roberts said the biggest 

issue is temperature consistency. “If you 

are holding 2µm tolerances or ultrahighprecision 

pitching accuracies, you need 

temperature consistency throughout. If 

you use long cutting processes at varying 

temperatures, [the workpiece] grows 

or shrinks, so how do you know where 

you’re at?” 

The company operates a small hole 

popper (Sodick AE05 microEDM). Even 

though the system has its own enclosure 

with environmental controls, external 

temperature control is important to 

ensure that parts can be measured away 

from the machine under comparable 

thermal conditions. 

Near-clean room controls. Micro 

Precision Parts Manufacturing of 

Vancouver, British Columbia, does not 

have a certifi ed clean room, but many 

systems are in place to control dust 

and dirt (air fi ltration and sticky mats), 

humidity and temperature. 

Company president Steve Cotton said 

that since a single speck of dust can ruin 

the fi nish on medical microparts, the 

parts are vacuum cleaned using a 30µm 

fi lter and wrapped in a lint-free material 

prior to shipping. 

Albright Technologies 

—Joel Cassola 

Albright 

Technologies built a 

Class 10,000 clean 

room to control 

particulates and 

temperature during 

silicone molding 

and inspection 

processes. 

temperature. However, this equipment— 

enclosure and all—may also be housed 

in a clean room that maintains temperature 

within ±1° C so that inspection 

equipment will measure the parts under 

thermal conditions comparable to those 


Clean Machining continued 

under which they were manufactured. 

Even builders of conventional products 

like motorcycles are insisting that critical 

components for their fuel-injection systems 

be machined and packaged in clean 

rooms so that there is no danger that a 

particle of dust will plug a critical orifi ce. 

How are clean rooms classifi ed? 

Clean rooms are typically classifi ed according 

to the number and size of particles 

within a given volume of air. Th e two most 

common standards are the now-defunct 

U.S. Federal Standard 209E and 

ISO14644-1, which replaced it. Th e 209E 

standard was cancelled by the General 

Services Administration of the U.S. Department 

of Commerce on Nov. 29, 2001, 

but is still widely used. 

The old Federal standard had six 

classes for clean rooms: 100,000, 10,000, 

1,000, 100, 10 and 1, with one being the 

cleanest. Th e ISO Classes 8 through 3 

correspond to these, with classes 2 and 1 

being even cleaner. 

Th e lower-number classes are typically 

found in industries like silicon chip and 

pharmaceutical manufacturing. Clean 

rooms used by micromanufacturers are 

most frequently Class 8 or Class 7. Th e 

classifi cation only tells part of the story, 

however, because there are many other 

features of a clean room’s design that 

have little if anything to do with its class. 

What are the key components of 

clean room and temperature control 

systems? Th e key component of a clean 

room is the fi ltration system (otherwise 

called a fan/fi lter, OPA fi lter or HEPA 

fi lter). Th is primary system may be used 

in conjunction with a wide range of additional 

systems, such as dehumidifi ers, 

air conditioning and bag-in/bag-out fi lters 

that make it easy to remove dangerous 

contaminants and incinerate them. 

Soft-sided clean rooms are like tents 

with open bottoms. Positive pressure prevents 

particles from entering the room. 

Th ey can be purchased for about $40 per 

square foot. Hard-walled clean rooms 

range from $120 to $200-plus per square 

foot, depending on the room’s class and 

the complexity of its particle fi ltration 

system and other environmental controls. 

Modular clean rooms cost less and 

can be disassembled and moved. Th ey are 

treated as equipment, not construction, 

so they depreciate faster. Conventionally 


Advanced Research Corp. machines aerospace and scientific instrument microparts 

in a class 10,000 clean room. The company operates an enclosed small hole popper 

(microEDM) with its own environmental controls. Still, external temperature control is 

important to ensure that parts measured away from the machine are under comparable 

thermal conditions. 

Albright Technologies 

Albright Technologies' shop supervisor, 

Jim Smith, "gowns up" before entering the 

company's Class 10,000 clean room. 

ARC 

constructed clean rooms typically cost 

more, but they allow for the greatest degree 

of design fl exibility. 

Operating costs include such things 

as power for various electromechanical 

systems, materials (fi ltration, cleaning, 

gowns, mats, etc.), maintenance and 

staff training. 

Clean rooms frequently require certifi - 

cation. Some clean room manufacturers 

off er this service; however, independent 

consultants, such as those who perform 

ISO certification audits, are a better 

choice for those who wish to avoid the 

appearance of a confl ict of interest. Monitoring 

devices may be installed in clean 

rooms to provide ongoing verifi cation 

that the desired standards are being met. 

Does having a clean room help solicit 

micromachining jobs? Maybe. 

It stands to reason that having a clean 

room could open the door to new jobs. 

However, the manufacturers consulted 

said that their decision to install a clean 

room had little to do with impressing 

prospective customers and more to do

with optimizing specialized processes 

the companies had developed for making 

high-value-added products. To them 

it was an essential ingredient, so they did 

not hesitate to build what they needed. 

In other cases, OEMs that want to 

minimize sources of contamination often 

drive the micromanufacturer’s decision to 

build a clean room. Manufacturers that 

adopt a “build it and they will come” attitude 

may have a hard time justifying the 

expense if they don’t come. 

How to avoid grief 

All of our respondents agreed that the 

three most important factors in developing 

a successful clean room operation for 

micromanufacturing are: 

1. Know the requirements. Understand 

completely the requirements of 

your customers and your processes and 

design and operate your clean room accordingly. 

Find out exactly which environmental 

factors need to be controlled 

and to what degree. Some manufacturers 


MICROMANUFACTURERS 

Albright Technologies Inc. 

(978) 466-5870 

www.albright1.com 

ARC Technologies 

(651) 789-9000 

www.arcnano.com 

Micro Precision Parts 

Manufacturing Ltd. 

(250) 752-5401 

www.precisionmicromachining.com 

CLEAN ROOM SUPPLIERS 

Clean Air Products 

(763) 425-9122 

www.cleanairproducts.com 

Starrco 

(800) 325-4259, x305 

www.starrco.com 

interview their customer’s customer to 

get a more accurate idea of the requirements. 

One manufacturer estimated the 

cost of change orders at $1,500 each. So, 

getting the specs right the fi rst time can 

be a real money saver. 

2. Develop a mindset. Th e people 

who work in clean rooms are themselves 

a major source of contamination. Workers 

must develop a mindset embracing 

the strict disciplines governing dress, behavior 

and part handling. Th is requires 

thorough training at the outset and con- 

tinual reinforcement of correct practices. 

3. Fill it. Have a realistic plan for acquiring 

a suffi cient amount of work to 

keep your clean room operating profi tably. 

An unused room—regardless of how 

clean it is—is a money waster. µ 

About the author: Joel Cassola is a 

freelance journalist and Web content 

consultant with more than 25 years of 

experience reporting on manufacturing 

systems and software. E-mail: joel. 

cassola@gmail.com. 

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Good vibration 

(control) 

Small vs. large machines: different approaches to countering vibration 


Machine tool builders off er a growing selection 

of machining centers that make parts 

with microscale features and to submicron accuracies. 

Th e machines come in a variety of sizes, 

from half-ton and smaller units with 4"×4"×4" 

work volumes to 5-ton and larger machines 

with work capacities of 20"×20"×20" and greater. 

All the machine confi gurations are seen to be 

eff ective in making very small parts. Th e level at 

which that production is achieved, however, differs 

somewhat in relation to machine size. While 

the smaller machines typically are less costly and 

more energy-effi cient than the larger units, the 

greater table capacity of the larger, more expensive 

machines enables them to create microfeatures 

on larger parts. 

One of the key diff erences among the machines 

is the type of operations they perform 

and how they counter negative machining infl 

uences, such as vibration and heat. Th e more 

massive components of the bigger machines 

permit operations such as hard milling and 

rigid tapping, but require additional features to 

control machining forces. Th e small machines’ 

more compact constituents, as well as the min- 

By Bill Kennedy, Contributing Editor 

imal cutting forces generated by the small cutting 

tools they employ, serve to signifi cantly 

reduce the need to quell vibration with sheer 

structural mass. 

Critical mass? 

Microlution Inc., Chicago, off ers two smallscale 

micro machine tools. Its 3-axis, 363-S 

vertical machining center has a 2"×2"×2" work 

envelope, a 2-sq.-ft. footprint and weighs about 

1,000 lbs.; the work volume of its new 4,600lb., 

3.4'×5.4' footprint, 5-axis 5100s VMC is 

4"×4"×4". 

According to Andrew Honegger, vice president 

of Microlution, there is nothing inherently 

wrong with the traditional idea that greater 

mass improves the vibration characteristics of 

a machine tool. “Mass does a good job of eliminating 

vibration,” he said. Th e diff erence really 

is in the application. A larger machine tool 

may be able to handle larger tools and workpieces, 

but “the diff erence in our line of thinking 

is that we are designing machine tools that 

are specifi cally geared toward only the small 

tools and small parts. Th at is where the design 

Atometric Kern Precision 

Small machines, like the 900-lb. G-4 Utra from Atomectric, rely on their compact design and low cutting forces to prevent vibration. Large 

machines, such as Kern’s 17, 600-lb. Nano VMC, rely on their massive bases.

constraints change a bit.” All Microlution 

machines are designed for cutters 

¼" (6.35mm) in diameter and smaller. 

Gary Zurek, president of Kern Precision 

Inc., Webster, Mass., agreed that the 

miniscule-part focus of the smaller machines 

may minimize the need for a massive 

machine base. “On the other hand,” 

he said, “I would argue that [with any machine] 

traveling at 1 to 2 Gs over 2" there 

will be vibration, and somehow these vibrations 

must be addressed.” 

As result, some of Kern’s machines for 

medium- to small-part machining are 

far from small. Th e company’s 17,600-lb. 

Pyramid Nano VMC has a 9.3'×10.5' footprint, 

has travels of 19.6"×19.6"×15.7" in 

the X, Y and Z axes, and can handle tools 

from 50μm to 18mm in diameter. Th e 

machine’s polymer-concrete-fi lled base 

and frame absorb up to 10 times more vibration 

than cast iron, improving tool life 

and imparting surface fi nishes fi ner than 

0.05μm R a, according to the company. 

Th e machine’s size also facilitates the use 

of hydrostatic drives, which also dampen 

vibration. Kern’s two smaller machines, 

the Micro and EVO, incorporate similar 

polymer-concrete bases but are targeted 

toward small and micro part production. 

Conversely, builders of small machines 

say their equipment is designed to be 

proportional to the size of the parts they 

are making. 

“We took a lot of eff ort to make our 

machines squat and stout, a structure that 

is as reasonably compact as possible,” said 

Th omas N. Lindem, president of Atometric 

Inc., Rockford, Ill. “We thought if 

we scaled it appropriately to the parts, it 

didn’t have to be an extremely heavy machine 

to be stiff .” Atometric’s G-4 Ultra 

I would argue that with 

any machine traveling 

at 1 to 2 Gs over 2" 

there will be vibration, 

and somehow these 

vibrations must be 

addressed. 

micromachining centers have a work 

area of 4"×4"×4" (with an 8" stroke available), 

a 2.3-sq.-ft. footprint and weigh 

about 900 lbs. 

Structural elements 

Regarding the role structural materials 

play in vibration damping, Lindem said he 

and his father, Atometric founder Th omas 

J. Lindem, previously designed large machine 

tools at Ingersoll Milling Machine 

Co., where they utilized cast iron, welded 

steel, granite and synthetic-granite bases. 

Th e diff erent materials, he said, “all have 

their advantages and disadvantages. I’m 

not advocating one over the other; they 

all make excellent systems, but for all of 

Kern Precision 

Although they may be less 

space- and energy-efficient 

than small machine tools, 

larger multiplatform machining 

centers have the torque to 

perform operations like rigid 

tapping and microdrilling, as 

illustrated in this 10mm-thick 

cutaway titanium part. The 

angled holes are tapped 

with a M3×0.5 thread, and 

taper from a maximum OD 

of 2.5mm to a section just 

0.9mm long and 0.1mm in 

diameter near the part’s base. 

them you have to look at all their characteristics. 

Granite is a great natural dampener, 

but thick steel also has some very 

well known stiff ness and frequencies, and 

we are using a heavy steel base.” 

According to Lindem, a key consideration 

in controlling vibration and maintaining 

machining accuracy is keeping 

what he calls the “force loop” as small as 

possible. Th e force loop, he explained, 

consists of a circle or square drawn 

through the workpiece, fixture, table 

and machine base, around the structure 

of the axes and through the spindle and 

the tool. “Th e goal is to make those distances 

as short as possible,” he said. If the 

same part is machined in a larger force 

loop, any element of defl ection will tend 

to increase vibration exponentially. Th at 

increase in vibration can be estimated 

by cubing the distances within the force 

loop. Lindem added that in many granitebase 

machines, the force loop is actually 

contained in the unit’s steel structure; in 

that case, a larger steel structure mounted 

on granite can develop more vibration 

than an all-steel structure that is smaller 

and more compact. 



Microlution 

The Microlution 5100s 5-axis 

micromachining center has a 3.4'×5.4' 

footprint and a work volume of 4"×4"×4". 

Makino 

A small V-22 VMC from Makino machined 

a mold for 5mm×5mm medical staples in 

hardened 420 stainless steel (50 to 52 HRC). 

Each staple required 0.10mm corner radii. 

Good vibration (control) continued 

Mark Jackson, associate professor in 

the Department of Mechanical Engineering 

Technology at the Purdue University 

College of Technology, agreed that 

the small-machine concept makes sense 

with respect to controlling vibration. For 

example, he said there is a signifi cant 

amount of work being done with Swissstyle 

lathes to machine medical parts, 

such as bone screws, from metal workpieces. 

“But they are still using existing 

techniques, which may not be appropriate 

for machining certain geometries,” he 

said. “Th ere is a need for dedicated machine 

tools that not only consistently produce 

those features but don’t suff er from 

vibration or thermal changes that [lessen] 

the ability to consistently control the size 

of very small parts.” 

When small parts are produced on 

large machines, he said, “chatter occurs 

because the machine tool is far too big; 

the size of the machine is disproportionate 

to the size of the components. You 

have a huge mass moving around, and the 

vibrations have to go somewhere. Th ey 

are regenerated and actually replicated 

on the surface of the part.” 

Scaling down machine tools may require 

an approach very diff erent from 

simply downsizing the equipment, Jackson 

said. “We came up with a prototype 

tetrahedral machine tool that had three 

Atometric 

The rotary axes of the 

G-4 Ultra micromachining 

center from Atometric are 

shown machining a 0.35"- 

cubed demonstration part 

from ½"-dia. bar stock. 

machined balls on the surface, connected 

via hollow columns to a fourth ball at 

the top of the vertex. Th e tetrapod, actually 

a truncated pyramid, is the most 

stable shape in nature. We fi ll those columns 

with oil, water or solids to tune the 

machine tool and damp out certain frequencies 

of vibration. All the vibrations 

attenuate towards the center of each circular 

ball.” 

Not exciting 

Another important step in controlling 

vibration, said Bill Howard, VMC product 

manager for Makino USA Inc., Mason, 

Ohio, is minimizing self-excitation between 

adjacent machine components. 

For example, although Makino’s Hyper 

2J micromachining center is the company’s 

smallest VMC, the machine has an 

8"×6"×6" work volume, a 6'×8' footprint 

and weighs 11,000 lbs. To minimize selfgenerated 

vibration, it is essential to ensure 

tight alignment and fi t between the 

machine’s drive elements and its basic 

structure. “Two metal surfaces rubbing 

against each other, even if they are 

ground, are still going to have potential 

to vibrate or oscillate against each other,” 

Howard said. 

To control that tendency, the ways of 

the Hyper 2J, the V-22 VMC (slightly 

larger and more production-oriented 


Good vibration (control) 

continued from page 42 Contributors 

than the Hyper 2J) and other of the company’s 

machines feature guideways lined 

with Tercite, a self-lubricating, thermoplastic 

bearing material. According to 

Howard, the stiff , rigid material is handscraped 

to maximize accuracy and create 

pockets that evenly distribute lubrication 

between machine components. Th e lining 

also provides a cushion between the 

diff erent elements of the machine tool. 

Th e cutting process itself can excite vibration. 

Microlution’s Honegger pointed 

out that when machines use micro cutting 

tools, “typically the cutting forces are 

a lot smaller, so the input that is causing 

the vibration has a much lower magnitude.” 

In addition, small-diameter tools 

generally are applied at much higher 

spindle speeds than larger tools. Th e 

higher-frequency vibrations the small 

tools produce are easier to control because 

vibration-damping mechanisms are 

correlated to the frequencies, according 

to Honegger. 

“Th e higher the frequency, the easier 

it is to damp, as long as you are careful 

Makino 

A small V-22 VMC from Makino equipped 

with a 0.050mm-dia. drill machined 61 

individual 0.002"-dia. microholes into a flat, 

0.020"-thick, 303 stainless steel workpiece. 

about structural resonances. Mass is definitely 

an eff ective vibration-elimination 

mechanism, but based on the type of 

input that we have from small tools, you 

don’t need as much of it.” 

It appears that both small and large 

machine tools for micromachining 

can effectively control vibration and 

other machining forces. What users 

have to decide, then, is what will the machine 

be used for, how fl exible it needs 

to be and if the added fl exibility is worth 

the added cost. µ 

Atometric Inc. 

(815) 986-7352 

www.atometric.com 

Mark Jackson 

Purdue University 

jacksomj@purdue.edu 

Kern Precision Inc. 

(508) 943-7202 

www.kernprecision.com 

Makino Inc. 

(513) 573-7200 

www.makino.com 

Microlution Inc. 

(773) 282-6495 

www.microlution-inc.com 

About the author: Bill Kennedy is a 

contributing editor to MICROmanufacturing 

and Cutting Tool Engineering magazines. 

Telephone: (724) 537-6182; E-mail: 

billk@jwr.com. 



continued from page 14 

he said. “I push them as much as I can 

by reusing them.” 

Th e chips a boring bar produces 

need to be evacuated from the hole, 

which is typically a blind-hole in Swissstyle 

machining. Th at’s because parts 

are produced from a continuous piece 

of bar stock unless work is being performed 

on the subspindle. Flood coolant 

is one method of chip removal, but 

through-the-tool coolant is generally 

preferred, which is available on even the 

smallest tools. “Th e 0.42mm tool has a 

coolant delivery port that is EDMed,” 

Laprade said. “It doesn’t actually go 

The chips a boring bar 

produces need to be 

evacuated from the hole, 

which is typically a 

blind-hole in Swiss-style 

machining. 

through the bar itself but comes out at 

the base of the neck and coolant easily 

penetrates the hole.” 

Th rough-coolant pressure ranges 

from about 100 to 2,000 psi. Th at’s the 

case at Tomak Precision, where Day 

prefers through-coolant but normally 

applies fl ood coolant for the fi rst piece. 

When Tomak Precision expanded 

by purchasing a small machine shop a 

few years ago, it acquired two Citizen 

Swiss-style machines. It also acquired 

a need for new tools. “Swiss machining 

was new to us, so small tooling was 

needed,” Day said, noting that he needs 

tools as small as 0.039" for boring a 

0.050" hole. 

He came across information about 

the Utilis Multidec boring bars from 

Genevieve Swiss at a machine show 

and decided to try them. Today, Tomak 

uses four diff erent styles of the boring 

tools. 

Day found tool life to be good, even 

when boring titanium. “I ran a 1,600piece 

titanium job, and I used two 


The importance of proper center height for a boring bar 

inserts for the whole run,” he said. Th at 

required boring a hole at an angle 

with a slight counterbore before the diameter 

stepped down to 0.088". Tolerance 

was 0.002". “We held a 31-rms 

fi nish,” Day said. “Th e part requirement 

was 63 rms.” 

Day noted that the feeds for microboring 

range from 0.0004 to 0.005 ipr 

with a DOC from 0.002" to 0.025". 

Taking a single boring pass is preferred. 

“I normally try to drill as close 

to nominal as I can,” he said. “With 

though-coolant, I can drill a lot faster 

than I can bore.” µ 

About the author: Alan Richter is senior 

editor of MICROmanufacturing. Telephone: 

(847) 714-0175. E-mail: alanr@jwr.com. 

Force 

Force 

A positive chip rake boring bar set 

on centerline provides the most 

efficient cutting. The positive rake 

reduces cutting force and heat. 

Chips are pulled from the inner 

wall for the best evacuation, and 

tool life is optimal. 

A neutral rake boring bar set on 

centerline requires more cutting 

force. Chips are moderately 

controlled but may poorly 

evacuate. Tool life is slightly 

reduced because of increased 

heat. 

Force 

Force 

A positive rake boring bar set 

above centerline and rotated down 

to achieve centerline. The effective 

rake is neutral, requiring more 

cutting force. Chips are moderately 

controlled but could have 

evacuation trouble. The increased 

heat slightly reduces tool life. 

A neutral rake boring bar set 

above centerline and rotated 

down to achieve centerline. The 

effective rake is negative, requiring 

increased force to shear the 

material. The chip is pushed back 

in the part’s wall, causing poor chip 

evacuation. The increased heat 

shortens tool life. 

Force 

A positive rake boring bar set 

below centerline and rotated up to 

achieve centerline. The effective 

positive rake improves chip flow 

except clearance is sacrificed, 

causing the tool to rub and 

bounce. The result is excessive 

chatter, heat and premature tool 

failure. 

Force 

A neutral rake boring bar set 

below centerline and rotated up to 

achieve centerline. The effective 

positive rake improves chip flow 

except clearance is sacrificed, 

causing the tool to rub and 

bounce. The result is excessive 

chatter, heat and premature tool 

failure. 



Genevieve Swiss Industries Inc. 

(413) 562-4800 

www.genswiss.com 

HORN USA Inc. 

(888) 818-HORN 

www.hornusa.com 

Pacifi c Precision Inc. 

(909) 599-8471 

www.pacifi cprecisioninc.com 

Tomak Precision 

(513) 932-7941 

www.tomak.com

MEASUREMENT matters 

continued from page 21 30.0 

A specifi c example of a recent development 

in SWLI is the TTM (transmissive 

media module) from Veeco 

0 

Metrology for measuring through 

microdevice packaging and other trans- 20μm 

parent media. “We have added the 

capability to look through transpar- 40μm 

ent materials, like glass in environmental 

chambers, to measure a part that is 60μm 

under temperature control or humidity 

changes,” Maksinchuk said. “You can 80μm 

do measurements in real time while the 

device is being exposed to a harsh envi- 

0 

ronment.” Applications include corrosion 

studies and MEMS devices used in extreme 

environments. 

As for future developments, Felkel mentioned energy applications, 

such as solar panels. SWLI would be used to help 

control the manufacturing process. “Th e solar panel itself can 

be as big as your desk, but [SWLI would measure] the busbars 

and fi ngers; those are things that you want to know the 

profi le of to understand how much material you are putting 

down and to control the process,” he said. 

In the area of MEMS applications, there is interest in effi - 

ciently making very bright LEDs. “A lot of that comes down 

to topography-based features,” Felkel added. “Th ese include 

roughness and the height of various layers as you stack the 

LEDs.” µ 

About the author: Susan Woods is a regular contributor to 

MICROmanufacturing and Cutting Tool Engineering magazines. 

E-mail: susanw@jwr.com. 

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terraces represent single 

atomic steps in the HOPG 

(Highly Ordered Pyrolytic 

Graphite) crystal lattice. 

The atomic terraces, or 

plateaus, are only a few 

angstroms high. 


PRODUCTS/services 

MICROEDM. Sarix SA’s MACHline micro 

electrical discharge machines feature 

the Twin Axis system, which allows 

multiple operations to be performed on 

one machine. These operations include 

electrical discharge drilling, sinker EDMing, 

wire electrode grinding, 3-D electrical 

discharge milling, laser ablation and 3-D 

scope measuring. The machine’s large 

work envelope permits microscale features 

to be produced on large parts. All X-, Y- 

and Z-axis travels are 100mm. Accuracy is 

±2µm. 

+41 91 785 81 71 

www.sarix.com 

MICROBELLOWS. Custom-designed 

microbellows from Servometer Precision 

Manufacturing Group LLC can be as 

small as 0.5mm in diameter. Composed 

of electrodeposited nickel, the devices 

can be used as metallic hermetic seals, 

volume compensators, pressure and 

temperature sensors and connectors. 

Pressure-responsive applications include 

use as precision springs, electrical contacts 

and flexible microcouplings. The devices 

can operate in temperatures from -423° 

to 350° F. 

(973) 785-4630 

www.servometer.com 


LINEAR STAGES. Aerotech Inc. offers 

ANT130-L long-travel, direct-drive 

linear stages for alignment, inspection, 

positioning and measurement stations. 

The low-profile stages employ a centerdriven, 

noncogging, noncontact linear 

motor and encoder as the driving element. 

Peak unloaded acceleration is 1G and 

maximum velocity is 350 mm/sec. The 

stages provide 1nm resolution, 50nm 

repeatability, 250nm accuracy and 3nm 

in-position stability. Eight models are 

available, with travels ranging from 35mm 

to 160mm. 

(412) 963-7470 

www.aerotech.com 

SWISS-STYLE MACHINING. American 

Swiss Products Co. Inc. turns parts 

with diameters down to 0.0025" and 

tolerances as tight as 0.0001" on Swissstyle 

machines. The ISO-certified company 

offers small-run, complex parts as well as 

long-run, less-complex parts. Secondary 

and finishing operations include broaching, 

drilling, grinding, knurling, laser etching, 

milling and threading. Industries served 

include aerospace, automotive, electronics 

and medical. 

(800) 805-9855 

www.americanswiss.com 

MEASUREMENT CENTER. Micro-Vu 

Corp.’s Vertex 120 measurement center 

features servo-staging, high-resolution 

encoders, 12:1 programmable zoom 

and programmable lighting. Systems 

include InSpec metrology software with 

point-and-click programming, proprietary 

edge-learning algorithms, instant reports 

and geometric dimensioning and 

tolerancing (GD&T). With vision and touch 

technologies, the machine can be used 

in medical, watchmaking, electronics, 

microEDM and laser applications. The 

company reports the Vertex 120 provides 

results in seconds. 

(707) 838-6272 

www.microvu.com 

MICRODRILLS. Atom Precision of 

America Inc.’s Neo-Pro-series solid-carbide 

microdrills are for multiple-hole drilling in 

a range of steels. The tools are available 

in short-, standard- and long-flute lengths. 

Diameters range from 0.03mm to 3mm, 

in 0.01mm increments. The drills feature 

wide chip pockets to enhance chip 

evacuation when high-speed and highfeed 

drilling. According to the company, 

the slight hones on drills larger than 

1.6mm in diameter extend tool life. 

(317) 889-1072 

www.atomprecision.com

ULTRASHORT-PULSE LASER. Norman 

Noble Inc. introduces the Noble 

UltraLight athermal, ultrashort-pulse 

laser for machining intricate features 

without producing a heat-affected zone 

in materials ranging from bioabsorbable 

polymers to shape-memory metals and 

exotic alloys. With its ability to machine 

athermally, the laser can reduce or 

eliminate the need for deburring and other 

post-processing procedures, according 

to the company. Applications include the 

manufacture of drug delivery systems, 

catheters, valves and needles. 

(800) 474-4322 

www.nnoble.com 

PROTOTYPING SERVICES. FineLine 

Prototyping offers an array of prototyping 

services, including stereolithography of 

large and small 3-D objects. The parts are 

as small as the head of a pin. A range of 

material and finish options are available. 

Other services include SLArmor, which 

involves finishing a ceramic-filled epoxy 

material with a metal coating, microfluidic 

device fabrication and selective laser 

sintering for production of limited-volume 

end use parts. 

(919) 781-7702 

www.finelineprototyping.com 

MICROMACHINING SERVICES. Johnson 

Matthey Medical provides products 

for orthopedic, endoscopy, cardiology, 

neurology and implant applications. The 

company machines, draws, rolls and forms 

platinum, Nitinol and specialty metals. 

Micromachining capabilities include wire 

EDMing, grinding, milling, turning, coating 

and electroplating. The company can CNC 

mill and turn parts as small as 0.1" and 

drill holes as small as 0.012" to tolerances 

of ±0.0005". Grinding is used for tube 

and wire components, with diameters to 

0.005" and tolerances to ±0.0002". 

(800) 442-1405 

www.jmmedical.com 

MACHINING CENTER. Mori Seiki USA 

Inc.’s NN1000 is a 5-axis machine tool for 

specialty mold production. The machine 

utilizes diamond milling or scribing tools 

and can machine features in the micron 

range with nanometer-level surface 

finishes. The maximum standard spindle 

speed is 56,000 rpm; higher speeds 

are optional. Symmetric DCG (Driven 

at the Center of Gravity) construction 

enables feeds of up to 4,500 mm/min. 

and minimizes thermal deformation. The 

machine features 1nm control resolution. 

(847) 593-5400 

www.moriseikius.com 

WATERJET MACHINES. Finecut AB, along 

with Sweden AB, offers Fine Abrasive 

Waterjet (FAW) machines for micro 

applications. With a kerf width of 0.3mm, 

the waterjets deliver the abrasive via water 

or air and provide cutting jet diameters 

from 50µm to 300µm. The machines 

provide a standard feed rate of 20 m/min. 

(double that in fast-feed mode). The basic 

machine features an encased stand-alone 

unit with a dedicated CNC operating panel 

and display screen. 

+46 70 6763355 

www.finecut.se 

LASER SHUTTERS. nmLaser Products 

Inc.’s FlexSorb laser shutters feature a highdamage 

threshold, quick switching speed 

and small size. The only moving part is a 

low-mass, flexible, ferromagnetic cantilever 

membrane that is moved in and out of 

the beam by noncontact electromagnetic 

techniques, which reduce shock, vibration 

and wear. The noncontact flexure closes 

at a position slightly away from the pole, 

essentially floating in air to eliminate any 

potential vibration or bounce. The units can 

be used in clean rooms. 

(408) 227-8299 

www.nmlaser.com 


RESEARCHroundup 

Geometry and Surface Damage in 

MicroEDMing of Microholes 

Bülent Ekmekci, Atakan Sayar, Tahsin Tecelli Öpöz and 

Abdulkadir Erden 

Scientists investigated the link between 

microEDM pulse energy and its effect on 

the geometry and subsurface damage to 

blind microholes. They used a tungstencarbide 

electrode at various pulses and 

a hydrocarbon-based dielectric liquid to 

machine microholes in plastic mold steel 

samples. Researchers found that the heatdamaged 

segments were composed of 

three distinct layers, each “relatively thick” 

and each at a different drilling depth. Even 

low-pulse energies caused crack formation 

in some sections of the microholes. They 

also observed that during machining, an 

electrically conductive bridge between the 

workpiece material and debris particles can 

form at the end tip; this leads to electric 

discharges between piled segments of 

debris particles and the electrode during 

discharging. The researchers concluded that 

the cracking mechanism when microEDMing 

microholes differs from the surface cracks 

caused by conventional EDMing. 

Journal of Micromechanics and 

Microengineering, 2009. The full study is 

available for purchase at www.journals.iop.org. 

Analyzing the Performance of 

Diamond-Coated Microendmills 

C.D. Torres, P.J. Heaney, A.V. Sumant, M.A. Hamilton, 

R.W. Carpick and F.E. Pfefferkorn 

Scientists detailed a new method to 

improve tool life and cutting performance 

of 300µm-dia., tungsten-carbide 

microendmills by applying thin (less than 

30nm), fine-grained diamond (FGD) and 

nanocrystalline diamond (NCD) coatings 

using the hot-filament chemical vapor 

deposition process. They evaluated the 

diamond-coated tools by comparing their 

performance in dry slot milling of 6061-T6 

aluminum against uncoated tungstencarbide 

microendmills. Overall, diamondcoated 

tools showed improvement in 

tool integrity (corners remained intact), a 

lower wear rate, no observable adhesion 

of aluminum to the diamond and a 

reduction in cutting forces (greater than 50 

percent). While about 80 percent of the 

tools coated with the larger FGD coatings 

failed during testing due to delamination, 

only 40 percent of the NCD tools had 


delamination problems. Also, the NCD 

films proved more robust; they were able 

to continue tool operations even after the 

coating had been compromised. 

International Journal of Machine Tool and 

Manufacture, 2009. The full study is available 

for purchase at www.sciencedirect.com. 

Surface Emitting Microlaser Based on 

2-D Photonic Crystal Rod Lattices 

Lydie Ferrier, Ounsi El Daif, Xavier Letartre, Pedro Rojo 

Romeo, Christian Seassal, Radoslaw Mazurczyk and 

Pierre Viktorovitch 

Researchers investigated optical properties 

of a 2-D photonic crystal (2-D PC) 

rod lattice under stimulated emission. 

They reported that, for the first time, 

stimulated emission around 1.5µm was 

demonstrated in the structures. They 

also showed that the use of rods allows 

for the control of the emitting area of a 

Bloch mode laser, through carrier-induced 

refractive index change. According to 

the researchers, the laser wavelength is 

sensitive to the device’s environment, 

“opening the way to a new type of 

integrated optofluidic device where liquid 

can flow through the resonator itself, 

reinforcing the sensitivity of the sensors.” 

Optics Express, 2009. The full study is available 

to download at www.opticsinfobase.org. 

Microstructuring of Glass with 

Features Less than 100µm by 

ECDMing 

Xuan Doan Cao, Bo Hyun Kim and Chong Nam Chu 

Researchers investigated the feasibility of 

using electrochemical discharge machining 

(ECDMing) to improve the machining of 

3-D microstructures of glass. In ECDMing, 

voltage is applied to generate a gas film 

and sparks on an electrode; however, a 

high voltage produces poor machining 

resolution. To obtain a stable gas film over 

the entire tool surface at a low voltage, 

scientists used a new mechanical contact 

detector, which is based on a load cell. 

Also, the immersion depth of the electrode 

in the electrolyte was reduced as much 

as possible. The researchers were able 

to fabricate various microstructures less 

than 100µm in size, such as 60µm-dia. 

microholes and a 10µm-thin wall. 

Precision Engineering, 2009. The full study is 

available for purchase at www.sciencedirect. 

com. 

The Microchannel of Microfluidic 

Chip Fabrication by Micropowder 

Blasting 

Chiung Fang Huang, Yung Kang Shen, Yi Lin, Chi Wei Wu 

Micropowder blasting involves high-speed 

gas flow combined with microparticles 

delivered to the substrate via a specialized 

nozzle. A study used various-sized 

aluminum-oxide powders (Al203 ) with 

a novel masking technique to make 

channels in a microfluidic chip made 

from soda glass 2,000µm wide and 

1,631µm deep. The masking technology 

involved two combined polymers: the 

elastic and thermal-curable polydimethyl 

siloxane, for its erosion resistance; 

and the brittle epoxy resin SU-8, for its 

photosensitivity. In evaluating the process, 

the scientists discussed a number of 

parameters, including micropowder 

impact pressure, the distance between 

nozzle and substrate, micropowder size 

and micropowder impact time. Results 

showed that micropowder size was the 

most important factor for achieving the 

desired depth of channel in the chip. The 

microchannel’s surface roughness was 

5µm Ra to 6µm Ra . 

Advanced Materials Research, 2009. The full 

study is available for purchase www.scientifi c. 

net/orderpaper/70645. 

3-D Microfabrication of Materials by 

Femtosecond Lasers for Photonics 

Applications 

Saulius Juodkazis, Vygantas Mizeikis and Hiroaki 

Misawa 

Researchers reviewed femtosecond 

laser fabrication of 3-D structures for 

photonics. In particular, they discuss: the 

production of photonic crystal structures 

by direct laser writing and holographic 

recording by multiple-beam interference 

techniques, the physical mechanisms 

associated with structure formation and 

post fabrication, and the advantages 

and limitations of various femtosecond 

laser microfabrication techniques for 

the preparation of photonic crystals and 

elements of microelectromechanical and 

micro-optofluidic systems. 

Journal of Applied Physics, 2009. The full study 

is available for purchase at www.commerce. 

aip.org/cart.do. 

µ

Taking Form continued from page 34 

capability may become a necessity for 

companies involved in 3-D microstructure 


Material variation 

Th e most common electrochemically 

deposited metals are gold, nickel, nickel/ 

cobalt and copper. Some combinations 

of these metals work well, such as copper 

and gold or nickel/cobalt and gold. 

Overplating the entire 3-D structure is 

problematic but possible, depending on 

the overcoat material. Gold over copper 

or nickel is possible. Platinum, palladium 

and rhodium are desirable overplating 

materials but can present plating issues 

related to the specifi c plating bath. 

Magnetic metal deposition baths are 

available and may be considered for those 

applications requiring magnetic proper- 

ADindex 

ties. However, complex and exotic solutions 

like this make the plating process 

more diffi cult. 

Future 3-D microstructure applications 

will likely require at least one of 

the above metal or coating options. For 

example, pure gold overplatings may be 

essential on copper-based RF coupling 

devices where biocompatibility is an issue. 

Similarly, dielectric overplating will be essential 

in applications where controlled 

dielectric characteristics are critical. (See 

Figure 6 on page 34 for an example of a 

device that has been overplated.) 

Th e enabling technologies mentioned 

previously are expected to make electroforming 

an even more commercially viable 

process. For example, projection imaging 

will enable the creation of electroformed 

features with resolutions of less than 1μm 

and aspect ratios of 10:1 or higher. Chem- 

ADVERTISER NAME PAGE # CONTACT NAME CONTACT PHONE CONTACT E-MAIL / WEB SITE 

Accumold 5 Aaron Johnson 515-964-5741 ajohnson@accu-mold.com / www.accu-mold.com 

Brush Research Mfg. Co. Inc. 7 Michael Miller 323-261-2193 sales@brushresearch.com / www.brushresearch.com 

Chardon Tool 13 Hugh McAllister 440-286-6440 hmcallister@chardontool.com / www.chardontool.com 

Excalibur Tool Inc. 39 Dan Wayman 541-862-2939 dansonly@earthlink.net / www.excalibur-tool.com 

FineLine Prototyping 27 Rob Connelly 919 781-7702 rob@finelineprototyping.com / www.finelineprototyping.com 

Harvey Tool Co. LLC Cover 4 Peter P. Jenkins 800-645-5609 pjenkins@harveytool.com / www.harveytool.com 

HORN USA Cover 2 Sebrina Carter 888-818-HORN sales@hornusa.com / www.hornusa.com 

ICOMM/4M 2010 35 Frank Pfefferkorn 608-263-2668 pfefferk@engr.wisc.edu 

ical mechanical polishing will support 

smaller multilayer structures and enable 

precision alignments of less than 1μm. 

Electroforming has already had a 

positive impact in several critical applications, 

such as semi-intrusive and 

permanent medical implants, telemetry 

and telecommunication devices and military 

devices. As the technology is developed 

further, it will enhance the use of 

3-D microstructures in existing applications 

and enable penetration into new 

applications. µ 

About the authors: Lowell Thomas 

is senior staff engineer and Luke Volpe 

is director of engineering (retired) for 

Dynamics Research Corp., Metrigraphics 

Division, Wilmington, Mass. Telephone: 

(978) 658-6100. Web site: www.drc.com/ 

metrigraphics. 

IMTS 2010 - Intl. Mfg. Technology Show 3 Jessica Aybar 703-827-5288 jaybar@amtonline.org / www.imts.com 

MachineTools.com Inc. 39 785-965-2659 info@machinetools.com / www.machinetools.com 

Micro Waterjet LLC 11 Coni Chamley 704-948-1223 cchamley@daetwyler.com / www.microwaterjet.com 

Microcut 8 Joe Dennehy 781-582-8090 info@microcutusa.com / www.microcutusa.com 

Performance Micro Tool 23 David Burton 866-PERFORM info@pmtnow.com / www.pmtnow.com 

Sandvik Coromant Co. Cover 3 Björn Roodzant 800-SANDVIK bjorn.roodzant@sandvik.com / www.sandvik.coromant.com/us 

Schütte TGM LLC 14 David Brigham 517-782-2938 davidtgm@acd.net / www.schuttetgm.com 

Society of Manufacturing Engineers 47 Marci Shannon 313-271-1500 mshannon@sme.org / www.sme.org 

Tungsten Toolworks 41 John Forrest 800-564-5832 john@toolalliance.com / www.tungstentoolworks.com 

U.S. Photonics Inc. 31 Kevin Whitworth 417-863-9027 info@usphotonics.net / www.usphotonics.net 

U.S. Union Tool Inc. 24 Jonathon Hay 714-521-6242 jon.hay@usuniontool.com / www.usuniontool.com 

VIEW Micro-Metrology 19 Tim Sladden 585-544-0450 ext. 460 tsladden@viewmm.com / www.viewmm.com 

Virtual Industries Inc. 33 Tom Mealey 719-572-5566 tmealey@virtual-ii.com / www.virtual-ii.com 

Xact Wire EDM 45 Michael Raasch 262-549-9005 mraasch@xactedm.com / www.xactedm.com 

Carl Zeiss IMT Corp. 21 Customer Service 800-327-9735 imt@zeiss.com / www.zeiss.com/imt 

The Advertisers Index is provided as a courtesy to advertisers. Every effort is made to avoid errors, but should one occur, MICROmanufacturing is not responsible. 

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IL 60062 and additional mailing offi ces. Circulated in the U.S.A. to qualifi ed individuals involved with micromanufacturing. For others, subscriptions are $35 per year in the U.S.A.; $45 in Canada. Other foreign 

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LASTword By Phillip M. Leopold, 

Medical Murray Inc. 

Thoughts from a medical 

micromanufacturing pioneer 


My son, Andy, and I bought Medical 

Murray Inc. in 1996. We design, 

develop and manufacture molded medical 

devices especially for minimally invasive 

treatments in three major areas—vascular, 

surgical and urological. 

Medical Murray, headquartered in Barrington, 

Ill., began as a mechanical consulting 

engineering company, with maybe a fourth of 

its business in the medical arena. We knew 

from the start that we were going to go 100 

percent into medical devices. We both recognized 

that there was a growing emphasis 

[in the medical arena] to make things smaller 

and saw the potential for using molding to do 

that. We specialize in making custom catheter 

systems and components, complex disposables 

and implantable devices. 

Th e biggest challenge in working at the 

microlevel is to get the molds to the needed 

precision, because the devices are so tiny. 

One of the fi rst things we did was to build an 

injection molding machine that incorporates 

a linear motor, which was fairly new at that 

time. We designed the machine so that a very 

small volume of plastic would melt, which we 

could precisely control as it was injected into 

the mold. In fact, the machine can be fi lled 

with 3 grams of material, so high-cost materials 

can be molded with minimal loss. 

Another important feature of the machine 

is its ability to inject plastic very fast. Th is allows 

thin areas of the mold to fi ll before the 

melted plastic solidifi es. Th e linear motor 

moves the injection ram at the rate of 1 meter 

per second. By comparison, typical hydraulic 

presses move at 0.2 m/sec. and ballscrewdriven 

electric presses move at 0.4 m/sec. 

When making devices that go into people’s 

bodies, you avoid rigid materials; you want 

something soft. For the most part, the materials 

used are polyurethane or silicone rubber. 

Th e primary ticket to the medical device 

game is the ISO 13485 medical quality certifi - 

cation. We don’t distribute products to the end 

user, so we don’t have to be registered by the 

U.S. Food and Drug Administration. 

Many manufacturers interested in entering 

the medical device industry ask how much 

volume there is and how much money they 

can make. Th ey see that the fi eld is growing 

and the work is remaining in the country—at 

least for high-end products like complex catheters 

that cost from $100 to $1,000 or more. 

Getting those types of products made off - 

shore can’t be justifi ed because of the high 

transfer and training cost, and because their 

volume is fairly small—maybe a few thousand 

a month. And while traditionally there have 

been pretty high margins in the fi eld, some of 

those margins are needed to help cover quality 

systems and associated liability issues. 

Many of the companies interested in the 

medical device industry don’t realize how 

long it takes to get a job from concept to production. 

We have several products now in 

production that we fi rst started working on 8 

years ago. We have as many as 30 to 40 diff erent 

projects in varying stages of development 

going on at any one time. Some might be on 

hold because we’re waiting for FDA approval 

or for some testing to come back; others are 

active because we’re making parts for a project’s 

next round of testing, and so on. About 

10 percent of product concepts make it to 

fi nal production, so it’s important to have different 

projects in diff erent stages of development 

in order to stay busy. 

It can be diffi cult to get on a big medical 

company’s approved-vendor list. As in any 

other industry, the larger companies don’t 

want 500 vendors for a part. Th ey want one 

or two that are qualifi ed and that they can 

work with. It’s rare that an OEM will switch 

vendors because of all that’s involved in getting 

the vendor qualifi ed, the parts certifi ed 

and conducting the requisite biocompatibility 

testing. 

Th e best strategy for getting on OEMs’ 

vendor lists is to be available and help them 

solve a problem that had been insurmountable. 

You make contact with people there so 

they know you and come to you when they 

need help. And then—as one of their “goto” 

sources—they’ll call on you again to help 

them on other projects. µ

Harvey Tool Company, LLC 

319 Newburyport Turnpike 

Rowley, MA 01969-1729 

800-645-5609 

978-948-8555 

978-948-8558 Fax 

Request your FREE catalog at: 

www.harveytool.com 

sales@harveytool.com 

All tools in the Harvey catalog (including 

tools featured here) are stocked as standards. 

No more machining headaches. 

The fine details are critical in your micro machining processes. With that in mind, 

we offer a broad range of specialty miniature tooling to help you make those 

difficult cuts. Miniature dovetails, miniature corner rounding end mills, miniature 

keyseats to name a few. Small tools, all in stock when you need them to prevent 

those machining headaches. 

All our tools are built to the highest quality standards in the industry. Our selection 

of miniature end mills includes standard flute, stub flute, and long flute mills; 

all are also available in long reach design. You can also choose from 2, 3, 4 or 5 

flutes and standard or high helix. When you need to go small, we’ve got the tool 

you need. Contact your local distributor for more details. 

Harvey Tool. Best selection in miniature tools. In stock when you need them.

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