Intel® Thermal/Mechanical Reference Design Information
R
48 Thermal/Mechanical Design Guide
5.7 Reference Attach Mechanism
5.7.1 Structural Design Strategy
Structural design strategy for the Intel RCBFH-3 Reference Solution is to minimize upward board
deflection during shock to help protect the LGA775 socket.
The reference design uses a high clip stiffness that resists local board curvature under the
heatsink, and minimizes, in particular, upward board deflection (
Figure 12). In addition, a
moderate preload provides initial downward deflection.
Figure 12. Upward Board Deflection during Shock
The reference metal clip nominal stiffness is 540 N/mm [3100 lb/in]. The combined reference clip
and fasteners nominal stiffness is 380 N/mm [2180 lb/in]. The nominal preload provided by the
Intel RCBFH-3 reference design is 191.3 N +/- 44.5 N [43 lb ± 10 lb].
Note: Intel reserves the right to make changes and modifications to the design as necessary to the Intel
RCBFH-3 reference design, in particular the clip and fastener.
Less curvature in region
under stiff clip
Shock Load