Hans: If you have pure Tin plated pins, electrically in contact with solder, this is VERY prone to corrosion, as you will be getting galvanically (does that word exist?) corrosion. Tin is much more electropositive than solder, and therefore will corrode readily when in contact with solder. Does this help? Rudy Sedlak RD Chemical Company ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################