Kontron COMe Starterkit Eval T2 - Manual (Page 196)

Mechanical Considerations
7.2.1. Top mounting
For top mounting heatspreaders with non-threaded standoffs (bore hole) are used.
This variant of the heatspreader was designed to be used in a system where the heatspreader
screws need to be inserted from the top side of the complete assembly. In this case the threads
for securing the screws are in the Carrier Board's standoffs. This is the reason why the
heatspreader must have non-threaded (bore hole) standoffs.
Figure 76: Complete assembly using non-threaded (bore hole) heatspreader
Note The torque specification for heatspreader screws is 0.5 Nm.
Caution Do not use a threaded heatspreader together with threaded Carrier Board
standoffs. The combination of the two threads may be staggered, which could
lead to stripping or cross-threading of the threads in either the standoffs of the
heatspreader or Carrier Board.
PICMG ® COM Express ® Carrier Board Design Guide Rev. 2.0 / December 6, 2013
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HSP stand-off
(Ø2.7mm bore hole)
Baseboard stand-off
(M2.5 thread)
Carrier board
COM Express Module
Heatspreader (HSP)
M2.5 Screw
and Washer