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From [log in to unmask] Fri Jun 21 08: |
41:15 1996 |
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I've seen information from capacitor vendors that characterize the
fracture strength of their components. In dealing with chip
capacitors.... there are many different materials and geometries that
are used to fabricate to different component values/specifications.
I have seen reports that include force curves for mechanical stress
(deflection, compression, and elongation) and thermal stress for
capacitors placed on a PCB. With appropriate interpretation these
curves can yield insight into the maximum allowable "twist(warpage)"
that can be tolerated. I've also seen tests that correlate the solder
amount to board bending.
Vendors that I have worked with have supplied these results per
request. I, however, have not seen a "general" reference. Is it
possible to check with your vendor for specific information?
______________________________ Reply Separator _________________________________
Subject: re:PWB flexing and SMT components
Author: [log in to unmask] at Internet
Date: 6/19/96 2:49 PM
Hi Suzanne
The only references found to date is the ANSI/J-STD-001 Joint Industry
Standard. Under section 9.0 Assembly Requirements their is a Bow and
Twist(Warpage) specification 9.2.3.
If you find something else please let me know. Hope this helps..
Does anyone have any good references on flexing of printed wiring boards
and
surface mount component (chip) fracturing?
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