I believe he is doing a finite element analysis of BGA solder joints and
wants to include the solder mask geometry to improve the accuracy of his
model since it will affect the solder joint shape and therefore the
reliability.

 -----Original Message-----
From:   [log in to unmask] [mailto:[log in to unmask]]
Sent:   Wednesday, March 07, 2001 6:01 AM
To:     [log in to unmask]; Hunter, Brian C
Subject:        Re: [TN] Soldermask geometry

Hi Brian,
All of these parameters can vary substantially. I would suggest either
looking at an number of cross-sections and averaging them, ot simply taking
one cross-section and model it. Question: What is the point of trying to
model SMD SJs? We certainly know their effects on SJ reliability.

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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