detection of cold solder

kschoon0129

dear,
appreciate if anyone able to share the best way of preventing or detecting cold solder in PCBA which related to SMT process.

thanks
kschoon0129

dbpage

The best method for a hobbiest (I think) is visual inspection. Look for a grayish, porous appearance. Visual inspection isn't perfect, for example, an inspector might miss non-wetting defects in which the solder is shiny, but did not adhere to a connection. The industry uses expensive milti-axis random vibration, rapid thermal cycling, or both to screen for solder joint and other defects. A Kester employee put this interesting article on SMT process defects on the internet: http://www.smtinfo.net/docs/Smtrecs.html

Post Edited (Dennis) : 9/15/2004 5:37:52 PM GMT

Jim Forkin

You need a good magnifying glass or a camera with a close up lense and lots of light. You must inspect each joint for a smooth appearance. On surface mount, a more common problem is that the solder has not flowed onto the part because it had lifted or shifted during the solder melting. You can spot this also by tipping the board and looking at the leads along the board axis. If you are soldering the smt parts by hand, good luck !
Jim