Jerry, Check out this article http://www.aimsolder.com/techarticles/reflow.htm ,which describes "step soldering" and may answer some of what you are inquiring about. Howard Watson Manufacturing Engineer AMETEK/Dixson Jerry Mosur <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 02/13/02 08:08 AM Please respond to "TechNet E-Mail Forum."; Please respond to Jerry Mosur To: [log in to unmask] cc: Subject: [TN] Reflow Process Hello, As a part of our preparations to set up an internal SMD line, I would like to get your opinion on the following topic. What are the problems, if any, associated with reflowing the double sided SMT board using solder paste with different melting points for top and bottom. Is this a fairly common process? If not what would you recommend as a best assembly process for double sided SMT boards? Thanks in advance, Jerry --------------------------------------------------------------------------------- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest 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 ---------------------------------------------------------------------------------