warp and twist

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I have been asked a very good question but have not been abl... - Feb 13, 2017 by Scott W

Assuming the traces run parallel and perpendicular to each o... - Feb 14, 2017 by davef

Hi Dave, Thank you for your inputs as they were good sugg... - Feb 14, 2017 by Scott W

Scott W

#77098

warp and twist | 13 February, 2017

I have been asked a very good question but have not been able to find a good answer. IPC for both PCB and PCBA refer to the X & Y dimensions to measure warp and twist but how would you determine the warp and twist for a round PCB or PCBA?

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davef

#77101

warp and twist | 14 February, 2017

Assuming the traces run parallel and perpendicular to each other, I'd choose one direction the traces run as "x" and the other direction for "y." Then I'd pick a unique identifier on the board to insure proper orientation. Next, I'd measure warp and twist according to IPC TM650. Then, I'd write a work method describing the procedure.

If traces don't run perpendicular and parallel, I'd pick a unique identifier on the board to insure proper orientation. Next, I'd measure warp and twist according to IPC TM650. Then, I'd write a work method describing the procedure.

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Scott W

#77104

warp and twist | 14 February, 2017

Hi Dave,

Thank you for your inputs as they were good suggestions. I however let out one important detail and that this is IMS material and not glass reinforced so I think that there is more bending going on during processing than warping and twisting

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