Fluid Jetting for Next Generation Packages - Nordson ASYMTEK 首页

higher fluid pressure (inside of the syringe)
helps force liquid down and around the
needle when it is raised. However, greater
pressure causes more fluid to be jetted with
each dot than that fluid which is directly
below the needle tip. Through a redesign on
the seat, the higher pressure could still be
used to force fluid below the needle, but as
the needle slammed down into the seat, there
would be greater backpressure to limit the
amount of additional fluid forced underneath
the needle tip. One of the alterations to the
jet that had the largest impact on dot size was
the switch from a 20-mil seat to a 15-mil
seat. It is proposed that by testing a 10-mil
seat, even smaller dots could be achieved. It
is also proposed that the opening length of
the seat be extended from 20 mils to 25 mils,
to potentially increase the backpressure.
With all other parameters kept constant, dot
size dropped from about 15.5 mil diameter to
about 12.5-13 mil diameter, by switching
seats, an approximately 16 percent reduction
in diameter (which corresponds to about a 40
percent reduction in volume). If this same
percentage decrease in size could be
achieved by switching to a 10-mil seat, then
dots in the 9.8-10.2-mil diameter range might
be produced. A 20 to 15-mil seat switch is a
25% drop, resulting in a 16% drop in
diameter, a 15 to 10 mil switch is a 33%
drop, potentially resulting in a 21% drop in
diameter.
Conclusions
Acknowledgement
The authors would like to thank Mr. A.P.
Babiarz for the experimental work and data
analysis and to Mr. J. Vint for his guidance
during this study.
Reference
Pac Tech, Berlin, April 2002