Intel
®
945G Express Chipset GMCH Thermal Design Guide
Reference Thermal Solution
4.3.2
Thermal Interface Material (TIM)
A thermal interface material provides improved conductivity between the die and heat sink. It is
important to understand and consider the impact of the interface between the die and heat sink
base on the overall thermal solution. Specifically, the bond line thickness, interface material area,
and interface material thermal conductivity must be selected to optimize the thermal solution.
It is important to minimize the thickness of the TIM, commonly referred to as the bond line
thickness. A large gap between the heat sink base and the die yields a greater thermal resistance.
The thickness of the gap is determined by the flatness of both the heat sink base and the die, plus
the thickness of the TIM, and the clamping force applied by the heat sink attachment method. To
ensure proper and consistent thermal performance, the TIM and application process must be
properly designed.
The 945G GMCH reference thermal solution uses Honeywell* PCM45F. Alternative materials
can be used at the user’s discretion. Regardless, the entire heat sink assembly, including the heat
sink, TIM, attach method must be validated for specific applications.
4.4
Board-Level Component Keep-outs
The locations of the hole patterns and motherboard component keep-outs for the GMCH can be
seen in Figure 8 and Figure 9. Dimensions are in inches.
Figure 8
GMCH Torsional Clip Heat Sink Motherboard Component Keep-out
Parallel Mean
Airflow Direction
2.218
2.398
2x 1.199
MCH
2x 1.109
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