Neil Maloney of Contemporary Control Systems asks, Solid Solder Deposit(SSD) technology 1. Does it work? 2. Is it cost effective? 3. Is there a "no-clean" sticky flux? I have used the Precision Pads Technology (PPT) solid solder deposit method for attachment of miniBGAs (10-mil dia. pads on 20-mil pitch and 15-mil dia. pads on 30-mil pitch). In my case I used a liquid RMA flux and cleaned it off after assembly. However, the sticky flux you refer to is merely solder- paste flux so I don't see why you shouldn't be able to get no-clean. Talk to your solder-paste supplier. Our mBGAs were bumped with 7-mil bumps of 63-37 eutectic solder. I had NO bridging and NO opens in any of the samples I soldered. I supplied the boards for application of the PPT solid-solder deposits with electroless nickel, gold flash pad finish but OSP would probably work too. Our volumes are small, prototype lots so I can't speak to the issue of cost effectiveness as compared to stencil printing in volume production. The stuff worked GREAT! In fact, if you want to convince yourself how good it is, try soldering J-leaded devices in a vapor-phase machine. You get virtually NO wicking of the solder up the leads and a great joint. If you want further details, contact me off-line. Gary P. --- Gary D. Peterson _/_/_/ _/ _/ _/ SANDIA NATIONAL LABORATORIES _/_/_/ _/ _/_/ _/ _/ P.O. Box 5800, M/S 0503 _/_/ _/_/_/ _/ _/ _/ _/ Albuquerque, NM 87185-0503 _/_/_/_/_/_/ _/ _/ _/_/ _/ Phone: (505)844-6980 _/ _/_/ _/ _/_/_/ _/ _/ _/_/_/_/ FAX: (505)844-2925 _/ _/_/ _/ E-Mail: [log in to unmask] _/_/_/ *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************