Kontron COMe Starterkit Eval T2 - Manual (Page 172)

COM Express Module Connectors
peg location holes in the PCB connector pattern are in the correct positions (as shown in the land
pattern of the COM Express Specification) and if the holes are drilled to the proper size and
tolerance by the PCB fabricator.
5.3. Connector and Module CAD Symbol Recommendations
The 440-pin COM Express connector should be shown in the Carrier Board CAD system as a
single schematic symbol and a single PCB symbol, rather than as a pair of 220-pin symbols.
This ensures that the relative position of the two 220-pin connectors remains correct as PCB
placement for the Carrier Board is done.
It also is very advantageous to extend this concept to include the COM Express Module outline
and the Module mounting holes in the same PCB land pattern. This allows PCB designers to
easily move the entire Module around to try placement options without losing the relative
positions and orientations of the Module connectors, mounting holes, and Module outline.
PICMG ® COM Express ® Carrier Board Design Guide Rev. 2.0 / December 6, 2013
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