Hi Doug, No, a thin silver coating does not improve solderability--it may however give a false indication of good wetting. Solderability will solely depend on the surface and material that you want to solder to; the silver will facilitate the easy spreading of the liquid solder on this surface because of the high solubility of Ag in tin. If the underlying surface is solderable, than Ag may improve wetting because of the somewhat faster spreading of the liquid solder; if the surface is not solderable, the Ag may still facilitate the spreading of the liquid solder without changing the non-solderable nature of the underlying surface. Thus, you may get the appearance of a properly wetted solder joint, but not have good wetting. If you have too much Ag in your solder joints, you can get into real trouble. The effect of Ag-Sn intermetallics was amply demonstrated in 1983 when Ag-plated PLCC-J leads from TI fell off circuit boards made by IBM-Austin as the result of the brittle and weak Ag3Sn intermetallic compounds. This event caused the formation of the IEEE Compliant Lead Task Group with 23 competing companies participating to investigate this occurrence and to gain understanding in the reliability achieved with compliant leads. Werner Engelmaier Engelmaier Associates, Inc. Electronic Packaging, Interconnection and Reliability Consulting 23 Gunther Street Mendham, NJ 07945 USA Phone & Fax: 201-543-2747 E-mail: [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************