Yousef 2 possibilities, both assuming the leads are a ferrous alloy and that what you are seeing is really rust: 1. The cut edge of the leads is not tinning during the soldering because a) the lead alloy is not solderable (e.g. containing nickel) and/or the flux used is insufficiently active. 2. You are using a rotary trimming knife after soldering (many systems in the past used solder-trim-solder) In both cases, you have a bare alloy exposed to the aqueous process, with an active DI water followed by a slow drying process: rusting is therefore inevitable until you manage to ensure that the cut ends are tinned correctly. This is a known problem. Brian MOTLAQY wrote: > Dears, > > Below is a short description of a problem we have faced recently at our > plant with the Through/Hole assemblies. > > Problem: Unacceptable formation of rust (brown to red color) on the CCA just > after cleaning (before and after wave solder) > Location: Exactly at the cutting edge of the T/H components leads (most of > the T/H components) > Process used: Semi-Aqueous cleaning (Prozone wash 45?C, Prozone/tap water > rinse 45?C, DI water rinse 50?C, then hot air forced drying 110?C) > > What could be the reasons for this problem and what do you recommend to > solve it and to prevent re-occurrence. > > Your expected useful response is highly appreciated in advance. > > Best regards, > > Yousef Almotlaq > Manufacturing Engineer > > Advanced Electronics Company - Saudi Arabia > > Email [log in to unmask] <mailto:[log in to unmask]> > Tel + 966 1 220 1350 X 3215 > Fax + 966 1 220 1355 > > ############################################################## > 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 > ############################################################## ############################################################## 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 ##############################################################