We took our 18W CO2 machining laser and tried some selective soldering with it. CO2 is IR and it will preferentially heat the surrounding dielectric. There was some potential, but we figured out another way of solving the problem. For through hole selective soldering, a machine using a tip that aims a small stream of solder at the joint seems to work well, although you don't have the kind of control available to the electric iron style of soldering system, so, particularly with Pb-free, there is a significant risk of over-eroding pads with low thermal mass while under-flowing pads with high thermal mass. I've done a lot of selective soldering of SMT parts with a "hot foot": You machine an aluminum fixture to have a "finger" which contacts the area you want to solder, providing a fairly high pre-heat. Usually we use vacuum to hold our typically thin boards down to this "finger", then use hot air on top to do the job. But that is obviously a re-work mode, and can't be done with components in the way of the "finger". Wayne Thayer -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Ray, Carl (GE Indust, GE Fanuc) Sent: Thursday, December 06, 2007 8:57 AM To: [log in to unmask] Subject: [TN] Laser Soldering vs Selective Soldering Hi All, How many of you "out there" have any experience with laser soldering machines verse selective soldering machines? Currently we have several types of selective soldering equipment but due to our designs we are having significant issues with adjacent components. I have seen some equipment but do not have experience with the venders or process. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------