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Date: | Tue, 2 Jul 2013 10:27:20 -0400 |
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Hi Rigo,
I have been out due to medical problems and only found your email on
TechNet today.
What we do is have IST coupons fabricated on the production panel with
DELAM circuits built in that can find material damage by measuring
changes in capacitance. What we do is to flood those planes in the
coupon that correspond to ground planes in the PWB and then we have one
or two coupons fabricated per production panel. We measure the
capacitance "as received" and compare it to the capacitance after reflow
and rework simulation and at end of test. A -4% change in the
capacitance suggests that there is significant material damage. What we
do is to microsection one or two of the failed coupons. We do failure
analysis on the coupons that fail our capacitance measurements. We find
that 95% of the time the coupons that exhibit -4% or greater reduction
in capacitance had material damage. What we find is adhesive
delamination, cohesive failure, material decomposition and crazing using
this method. After you do the failure analysis you can remove those
corresponding PWBs from the production lot.
This method only works on representative IST coupons however not on
finished boards.
Let me know if you would like more information on this method.
Sincerely,
Paul Reid
Program Coordinator
PWB Interconnect Solutions Inc.
235 Stafford Rd., West, Unit 103
Nepean, Ontario Canada, K2H 9C1
613 596 4244 ext. 229
Skype paul_reid_pwb
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-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Garcia, Rigo
(GSFC-300.0)[ARES CORP]
Sent: June 19, 2013 9:24 AM
To: [log in to unmask]
Subject: [TN] Non-destructive delamination inspection?
Hi everybody,
Does anybody know if there is a non-destructive delamination inspection
method around? Other than plain visual inspection I mean.
Best regards,
Rigo Garcia
Principal Flight Hardware Technology Assurance Engineer
NASA, Goddard Space Flight Center
Workmanship Standards, Code 300
Phone. (301) 286-6129
Fax. (301) 286-6576
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