AMD-K6-2E/400AFR AMD [Advanced Micro Devices], AMD-K6-2E/400AFR Datasheet - Page 306

• Manufacturer Part Number: AMD-K6-2E/400AFR
• Manufacturer: AMD [Advanced Micro Devices]

AMD-K6™-2E Processor Data Sheet
Heat Dissipation Path
16.2
288
Measuring Case Temperature
Thermal grease is recommended as interface material because
it provides the lowest thermal resistance (@ 0.20°C/W). The
required thermal resistance (
example is calculated as follows:
Figure 100 illustrates the heat dissipation path of the processor.
Due to the lower thermal resistance between the processor die
junction and case, most of the heat generated by the processor
is transferred from the top surface of the case. The small
amount of heat generated from the bottom side of the processor
where the processor socket blocks the convection can be safely
ignored.
Figure 100. Processor Heat Dissipation Path
The processor case temperature is measured to ensure that the
t h e r m a l s o l u t i o n m e e t s t h e p ro c e s s o r ’s o p e ra t i o n a l
specification. This temperature should be measured on the top
center of the package, where most of the heat is dissipated.
Figure 101 on page 289 shows the correct location for measuring
the case temperature. The tip of the thermocouple should be
secured to the package surface with a small amount of
thermally conductive epoxy. A second location along the
thermocouple should also be secured to avoid any movement
during testing.
If a heatsink is installed while measuring, the thermocouple
must be installed into the heatsink via a small hole drilled
through the heatsink base (e.g., 1/16 of an inch). Secure the
thermocouple to the base of the heatsink by filling the small
hole with thermal epoxy, allowing the tip of the thermocouple
to protrude the epoxy and touch the top of the processor case.
q
SA
=
q
Preliminary Information
CA
–
Thermal Design
q
IF
= 1.25 – 0.20 = 1.05(°C/W)
Ambient Temperature
Case temperature
q
SA
) of the heatsink in this
22529B/0—January 2000
Thin Lid
Chapter 16