Hi Tom,
Your TSOPs most likely have an Alloy 42 lead frame. Under the best of
circumstances, Alloy 42 does not get solder joints of the same quality as you
get with Cu. However, there is some Alloy 42 that appears in components
occasionally that is not wettable. If that is the case, the only solution is
part replacement.

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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