>From: Ron Olinyk <[log in to unmask]> >Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>, Ron >Olinyk <[log in to unmask]> >To: [log in to unmask] >Subject: [TN] Hand soldering fine pitch SMT >Date: Wed, 27 Nov 2002 15:48:30 -0600 > >Can anyone recommend good soldering technique for >hand assembly of 20mil pitch devices and 0603, 0402 >SMT chips? We are looking at doing some protoype >assembly on some fairly dense (and small) pcbs. We >were thinking of using solderpaste and one of those >portable solder pens with a hot air tip ie. Weller >Portasol. Has anyone had success using this >technique? >Thanks >Ron. A commonly used technique that I've used successfully for fine-pitch devices is to apply liquid flux to the pads, tack the device down at the corner leads, then 'flood' the leads with solder, using a soldering iron with a medium tip. You then remove the excess solder with desolder braid, and touch up any suspect joints with a fine tip on the soldering iron. The problem with solder paste is that it is difficult to get the right quantity on the pads. A stencil would probably help with this, but can be quite expensive for a prototype board. I have used solder paste with a Weller Pyropen with 0805 passives, and ICs. Leon -- Leon Heller, G1HSM Tel: +44 1424 14790 Email:[log in to unmask] My web page: http://www.geocities.com/leon_heller _________________________________________________________________ MSN 8 with e-mail virus protection service: 2 months FREE* http://join.msn.com/?page=features/virus --------------------------------------------------- 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 -----------------------------------------------------