I did not give any details as I wanted to understand all the possibility
which could contribute to via cracking. Does anyone have white papers on the
subject?

Assuming the boards were made correctly, what in the manufacturing process
could contribute to this defect. From the report it is mainly occuring near
ICs (QFPS, SOICs).


-----Original Message-----
From: Werner Engelmaier [mailto:[log in to unmask]]
Sent: Tuesday, December 03, 2002 2:42 PM
To: [log in to unmask]
Subject: Re: [TN] via cracking


Hi Dennis,
Via barrel cracking typically--you do not give any details--occurs as the
result of the much larger thermal expansion of the resin surrounding the via
than the copper of the barrel during soldering processes. There are
contributing factors, i.e. PWB design, hole quality, barrel copper quality,
resin content, etc.
I give a one-day workshop on this [see outline at website].

Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL  32174  USA
Phone: 904-437-8747, Fax: 904-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com

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