Hi Edwin, You sure have a mish-mash of opinions, half-truths, and facts. It is not the lead finishes that are doing it to you. Depending on the details, it is the solderability--or lack thereof--of the Alloy 42, together with posiible a large thermal expansion mismatch as well as a lead geometry which is not really compliant (and thus does not do anything for you). First, not all Alloy 42 is the same; while all contain about 42% Ni, the rest is Fe; Ni is solderable--sort of, it needs much more thermal energy to go into solution with Sn than does Cu--and Fe is not solderable at all. Manual soldering delivers higher amounts of heat and therefore give typically better results than standard reflow. However, there is some Alloy 42, presumably coming from a south Korean mill, that is not solderable not matter what you do; HP-Boise ran into this some years ago and published their negative experience to their credit. Second, as you recognize this saying "My experience shows has been that tin/lead plating has to be reflowed in order to be a protective film. This type of plating is very porous and the lead oxidizes easily." This is correct. Thirdly, Alloy 42 lead-frame TSOPs have a large CTE-mismatch with FR-4 PWBs; large size die makes things worse yet. Depending of what your product sees in terms of burn-in, testing, and severity of use environments, you may or may not see SJ failures in time frames that matter. Fourthly, solder joint pull forces are not a good indicator of anything. A much better understanding of what goes on can be gotten from looking at the fracture surfaces of this pull test--whether the fracture is interfacial or goes through the solder tells volumes about the quality of the SJs achieved. 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 ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################