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Date: | Fri, 2 Jul 2010 16:12:27 +0100 |
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I'm wondering about an issue we have with the dimensional stability of a
substrate made of FR4.
We're finding it's deforming during a flex attach operation, not by much
but enough to cause us a problem. We use ACF and a hot bar. The
substrate sees a temperature of 155 deg C for about 10 seconds. Someone
suggested that the movement may be due to incomplete curing of the
substrate.
I'm wondering if a temperature of 150 deg C for 10 seconds is likley to
have any effect at all on the matrix.
If it did, would the volume of the matrix increase, decrease or stay
much the same?
I realise that we'll see deformation due the application of pressure as
well but in some instances the substrate seems to be moving in the wrong
direction.
Thanks,
--
Eric Christison
Consumer& Micro group
Imaging Division
STMicroelectronics (R&D) Ltd
33 Pinkhill
Edinburgh EH12 7BF
United Kingdom
Tel: +44 (0)131 336 6165
Fax: + 44 (0)131 336 6001
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