PWB flexing and 1812 ceramic capacitors
We build boards for space and they must be bonded and riveted to rigid aluminum frames to withstand the environments. We currently specify the IPC-6012 requirements which are 0.75% bow and twist.
There is a concern that we may need to specify 0.5% bow and twist to prevent 1812 and possibly 1206 ceramic capacitors from developing cracks after the boards are attached to the frames.
With our boards, .75% translates to a maximum of 45 mils of bow and twist. Any thoughts on problem areas?
The boards are normally .090 thick, 8-12 layers and polyimide.
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