I recommend you thermocouple the ceramic, and also have it checked for moisture
content.  Something seems wrong.

I'd expect the solder joints to fail before the ceramic if its a thermal
expansion stress problem.

You could have a bad batch of ceramics.  Also, you may want to look at columns
instead of balls.

Jim Herard
IBM Microelectronics
Quality Engineering

---------------------- Forwarded by Jim Herard/Endicott/IBM on 06-12-97 05:38 PM
 ---------------------------

        ssmith @ ael.com
        06-11-97 05:22 PM
Please respond to [log in to unmask] @ internet


To: TechNet @ ipc.org @ internet
cc:
Subject: FEB:  ceramic BGA cracking after wave solder

We are experiencing cracking of large (1.8" on a side) ceramic BGA cracking
(like in half) following wave solder.  The devices are on polyimide boards.
This is a new program -- any advice on things we might do better or
different ... bake the boards before we stuff them?  fixture boards during
wave solder? go back to our board supplier for resolution?  Thanks for any
help...

Sheila Smith, Tracor AES

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