Guidelines

Dual-Core Intel
®
Xeon
®
Processor 7000 Sequence Thermal /Mechanical Guidelines 29
Thermal Mechanical Design
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
10.16 mm [0.400 in.] large diameter holes to compensate for the CEK spring embosses.
The CEK solution is designed and optimized for a baseboard thickness range of 1.57 – 2.31 mm.
[0.062-0.093 in]. While the same CEK spring can be used for this board thickness range, the
heatsink standoff height is different for a 1.57 mm [0.062 in] thick board than it is for a 2.31 mm.
[0.093 in] thick board. In the heatsink assembly, the standoff protrusion from the base of the
heatsink needs to be 0.6 mm. [0.024 in] longer for a 2.31 mm [0.093 in] thick board, compared to a
1.57 mm [0.062 in] thick board. If this solution is intended to be used on baseboards that fall
outside of this range, then some aspects of the design, including but not limited to the CEK spring
design and the standoff heights, may need to change. Therefore, system designers need to evaluate
the thermal performance and mechanical behavior of the CEK design on baseboards with different
thicknesses.
Refer to Appendix A for drawings of the heatsinks and CEK spring. The screws and standoffs are
standard components that are made captive to the heatsink for ease of handling and assembly.
Contact your Intel field sales representative for an electronic version of mechanical and thermal
models of the CEK (Pro Engineer*, IGES and Icepak*, Flotherm* formats). Pro Engineer, Icepak
and Flotherm models are available on Intel Business Link (IBL).
Note: Intel reserves the right to make changes and modifications to the design as necessary.
Note: The thermal mechanical reference design for the Dual-Core Intel Xeon processor 7000 sequence
was verified according to the Intel validation criteria given in Appendix C.1. Any thermal
mechanical design using some of the reference components in combination with any other thermal
mechanical solution needs to be fully validated according to the customer criteria. Also, if
customer thermal mechanical validation criteria differ from the Intel criteria, the reference solution
should be validated against the customer criteria.
2.4.4.3 Structural Consideration of the CEK
As Intel explores methods of keeping thermal solutions within the air-cooling space, the mass of
the thermal solutions is increasing. Due to the flexible nature (and associated large deformation) of
baseboard-only attachments, Intel reference solutions, such as CEK, are now commonly using
direct chassis attach (DCA) as the mechanical retention design. The mass of the new thermal
solutions is large enough to require consideration for structural support and stiffening on the
chassis. Intel has published a best know method (BKM) document that provides specific structural
guidance for designing DCA thermal solutions. The document is titled Chassis Strength and
Stiffness Measurement and Improvement Guidelines for Direct Chassis Attach Solutions.
2.4.5 Thermal Solution Performance Characteristics
Figure 2-11 shows the thermal performance and the pressure drop through fins of the heatsink
versus the airflow provided. The best-fit equations for these curves are also provided to make it
easier for users to determine the desired value without any error associated with reading the graph.