Intel Xeon Processor with 800 MHz System Bus Thermal/Mechanical Design Guide

26 Intel® Xeon™ Processor with 800 MHz System Bus Thermal/Mechanical Design Guidelines
Thermal/Mechanical Reference Design
2.4.4.2 Assembly Drawing
The CEK reference thermal solution is designed to extend air-cooling capability through the use of
larger heatsinks with minimal airflow blockage and bypass. CEK retention solution can allow the
use of much heavier heatsink masses compared to the legacy limits by using a load path directly
attached to the chassis pan. The hat spring on the secondary side of the baseboard provides the
necessary compressive load for the thermal interface material. The baseboard is intended to be
isolated such that the dynamic loads from the heatsink are transferred to the chassis pan via the stiff
screws and standoffs. This reduces the risk of package pullout and solder-joint failures.
The baseboard mounting holes for the CEK solution are at the same location as the hole locations
used for previous Intel Xeon Processor thermal solution. However, CEK assembly requires 1.016
cm [0.400 in.] large diameter holes to compensate for the hat spring embosses.
The CEK solution is designed and optimized for a baseboard thickness range of 0.157 – 0.231 cm.
[0.062-0.093 in]. While the same hat spring can be used for this board thickness range, the
heatsink standoff height is different for a 0.157 cm [0.062 in] thick board than it is for a 0.231 cm.
[0.093 in] thick board. In the heatsink assembly, the standoff protrusion from the base of the
Figure 2-7. Exploded View of CEK Thermal Solution Components