A historical note: What ever happened to step soldering using different vapor phase fluids of precise boiling points? As I recall there was a paper on this by NT (?) about such a process run very successfully at their West Palm Beach facility at one of the NEPCON technical proceedings some years ago. Proper selection of the alloys used and the K-Fluids (which boiled about 30 degrees apart, as I recall) allowed this step soldering to be done with ease. In some cases, mixed K-Fluids were used to 'tailor' the vapor phase to the alloys in use. The entire range went from K-6 (typical for eutectic tin-lead) up to K-10, which could melt pure tin. Bill Kenyon Global Centre Consulting P.O. Box 553, Montchanin, DE 19710 USA Tel: 302.652.4272 Fax: 302.652.5701 Cell: 302.377.4272 email: [log in to unmask] --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 -----------------------------------------------------