If immersion tin does whisker, wouldn't exposed traces (not solder pads) be a concern even after assembly? Is whisker growth a function of the environment or just time? Could the tin in the immersion tin process be alloyed (with a small percent of something else) to prevent whisker growth? BTW, my interest is to get away from HASL. It seems that two good alternatives are immersion tin and OSP. My applications are airborne military and space, though. Jim Marsico Senior Engineer Production Engineering AIL/Electronics Systems Group An EDO Company [log in to unmask] <mailto:[log in to unmask]> --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------