3 Heatspreader
An important factor for each system integration is the thermal design. The heatspreader
acts as a thermal coupling device to the module. It is a 2mm thick aluminum plate.
The heatspreader is thermally coupled to the CPU via a thermal gap filler and on some
modules it may also be thermally coupled to other heat generating components with the
use of additional thermal gap fillers.
Although the heatspreader is the thermal interface where most of the heat generated by
the module is dissipated, it is not to be considered as a heatsink. It has been designed
to be used as a thermal interface between the module and the application specific
thermal solution. The application specific thermal solution may use heatsinks with fans,
and/or heat pipes, which can be attached to the heatspreader. Some thermal solutions
may also require that the heatspreader is attached directly to the systems chassis
therefore using the whole chassis as a heat dissipater.
Caution
The center mounting hole on the heatspreader must be used to ensure that all
components that are required to make contact with heatspreader do so. Failure to utilize
the center mounting hole will result in improper contact between these components and
heatspreader thereby reducing heat dissipation efficiency.
Attention must be given to the mounting solution used to mount the heatspreader and
module into the system chassis. 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.
For more information about this subject refer to Application Note
AN14_ETX_XTX_Mounting_Solutions.pdf that can be found on the congatec website.
Copyright © 2006 congatec AG
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