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Date: | Wed, 27 Jul 2005 19:53:33 EDT |
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Hi Steve,
These BGAs with heatsinks, sometimes called Super-BGAs (SBGAs) are devices
that are unbalanced in terms of their thermal expansion/contraction
caracteristics. Depending on how stiff the heatsinks are attached to the BGA, you will get
component warping--remember the bi-metallic strip effect--that can get high
enough to rip attachment pads out of the PCB matrix. In any case, it is the
weakest link that fails--in your case the attachment of heatsink/BGA.
Regards,
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904
E-mail: [log in to unmask], Website: www.engelmaier.com
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