MIPS R10000 Microprocessor User's Manual - SGI TechPubs Library

222 Chapter 13.
Thermal Characteristics
Errata
The 599CLGA incorporates a copper-tungsten slug to provide an efficient thermal
path from the processor to the heatsink.
The thermal analysis listed in Table 13-2 gives a preliminary indication of heatsink
requirements for the 599CLGA.
Table 13-2 R10000 599CLGA Thermal Characteristics - Preliminary
Revised Table 13-2.
Assembly Drawings and Pinout List
Parameter Description Value
Tc Maximum case temperature 85˚ C
T ‡
a Maximum ambient temperature 40˚ C
PR10000 Maximum power dissipation 30 watts
Tja Minimum temperature differential 45˚ C
Θ ‡
ca Required case to ambient thermal resistance 1.5˚ C/W
‡ Θ ca is used as an example to calculate the ambient temperature, T c , needed.
System designers must take care, especially in desktop applications, to ensure
sufficient airflow and heat-dissipation surface area to meet the required case-toambient
thermal resistance, Θ ca .
The thermal interface between the package and heatsink is very important.
Typically, grease or compliant material is inserted between the package and
heatsink to increase the contact area between their surfaces.
The following pages contain a pinout list (Table 13-3), and drawings of an example
R10000 LGA-PWB assembly, including details of the PWB, heatsink, and bolster
plate. Actual hardware specifications are dependent on the user.
An assembly drawing of the 599LGA is also shown in Figure 13-2. Note that
hardware specifications given in this drawing will require modifications to
accommodate the actual dimensions of the socket, PWB, heatsink, bolster, etc.
Version 2.0 of January 29, 1997 MIPS R10000 Microprocessor User's Manual