Intel Core 2 Duo Processor - Figure 26. Step 4 - Backplate Pins

CPU Thermal Solution (Heatsink) Installation
76 Development Kit User’s Manual
4. Place the backplate on the underside of the development board so that the pins
protrude through the holes in the development board around the processor. (See
the figure below.)
Figure 26. Step 4 - Backplate Pins