Electronics Forum | Fri Jun 25 11:52:30 EDT 2004 | waveroom
What are the specifications on the solder that you use? IE: Water soluble,RA,RMA, N/C? Also do you clean the boards and if so how and what detergent if any are you using?
Electronics Forum | Fri Jun 25 12:10:34 EDT 2004 | tcp
We use water soluble paste, Kester R560. These units are wave soldered and cleaned in an Electrovert Aquastorm water wash with a 3% Kester saponifier solution in the first stage.
Electronics Forum | Fri Jun 25 16:18:26 EDT 2004 | waveroom
For what its worth. Even though you are potting the boards. If for whatever reason flux residue (OA) was left on the board prior to potting this flux could migrate and cause embrittlement problems with the solder joint. I would definately inspect for
Electronics Forum | Fri Nov 12 10:00:42 EST 1999 | Dave F
Edmund, following-on from Wolfy: Back in the old days, anyone who could spell "sodder" considered "bright and shiny connections" GOOD and "dull and grainy connections" BAD. Now, "dull and grainy" connections can be either GOOD or BAD, depending on
Electronics Forum | Fri Jun 25 11:29:43 EDT 2004 | tcp
We have had some field returns of a double sided SMT board manufactured in the February timeframe. The boards are encapsulated in an epoxy potting. When removing the potting some SSOP devices came off in the potting. The leads had pulled out of th
Electronics Forum | Thu May 10 08:09:52 EDT 2007 | davef
There is no standard for time above liquidus. It is described rather broadly by the solder paste supplier. Reflow Zone: If the temperature is too high, boards may char or burn. If the temperature is too low, cold and grainy solder joints will resul
Electronics Forum | Tue Apr 10 13:43:13 EDT 2001 | mparker
since you did not define what visual process you are inspecting with I will ask is this "grainy" appearance being detected with the naked eye only? Are you using magnification? if so, what power? Is this a SMT solder or through hole solder problem?
Electronics Forum | Mon Dec 06 09:16:22 EST 1999 | Dave F
Russ: Three things: 1 Wolfgang is 100% correctamundo about the slow dissolution rate of gold 2 Shear stength of the gold 63/37 solder connection decreases rapidly, as the gold content of the solder connection increases above 2%. 3 There are many
Electronics Forum | Fri Jun 25 13:25:04 EDT 2004 | russ
Sounds like the wrong reflow profile was possibly used on this batch, Or you have a lead solderability problem. Usually you will pull a pad off of the board instead of the lead out of the solder joint. When a lead is torn from the joint it will ha
Electronics Forum | Fri Jun 25 14:39:59 EDT 2004 | Hoss
Any chance your potting compound was changed in the timeframe mentioned or the unit(s) were used under high heat stress conditions? If significant thermal expansion of your potting material happened and it is a hard durometer, it could shear at your
