Electronics Forum | Tue Mar 11 12:20:13 EST 2003 | Jim
Look at "Dave's Book Shelf" here: http://www.smtinfocus.com/bookshelf/bookshelf.html
Electronics Forum | Mon Sep 26 16:48:32 EDT 2005 | PWH
Are you using masking? Conformal coat will de-wet (no pin holes usually, though) due to masking tape adjacent to affected areas if the tape glue chemistry isn't compatible with the conformal coat.
Electronics Forum | Mon Apr 28 11:13:21 EDT 2008 | ck_the_flip
Here's a crude wettability test. Take a PCB - both types of finish - print them, and reflow with no components using your standard profile. Observe the wetting spread and flow of the solder paste. This rules in/out that it's PCB solderability.
Electronics Forum | Mon Jul 28 10:58:34 EDT 2008 | davef
Search the fine SMTnet Achives for background discussion on dewetting, like: http://www.smtnet.com//forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=12840&#Message54734
Electronics Forum | Wed Aug 27 15:48:05 EDT 2008 | grics
Again, our paste manufacturer specifies TAL to be 30-60 seconds. Out of curiousity, how would part placement cause de-wetting? I am fairly new to SMT so elaboration would be helpful... Thanks
Electronics Forum | Mon Mar 01 09:17:56 EST 2010 | duso02
Hey....I think it might be the silicone adhesive! LOL Yeah, that'll do it. We use simple Shercon paper dots. Work like a charm. No evidence of "de-wetting".
Electronics Forum | Fri Jul 28 12:16:34 EDT 2017 | dontfeedphils
I'm pretty sure that in the job description of each QA related position it lists "Ensure Process Engineering is always being hassled because you inspect to target and not acceptable."
Electronics Forum | Thu Aug 19 19:04:55 EDT 1999 | Brian Wycoff
| | Can anyone help on the subject of de-wetting during the spray coating process. We use PC29M Parts A+B spray coating material, Humiseal tapes and masking dots, Marigold supertouch V70N gloves and Concoat CM533 liquid masking material. We also use
Electronics Forum | Mon Mar 30 03:10:44 EST 1998 | Patrick Ng
Hi, We have encountered de-wetting issues with gold plated components( SMT LEDs ). The problem comes and go and we yet to locate the root cause ( process, component or solder paste etc ). The rest of the components on the boards are not having this
Electronics Forum | Fri Mar 07 21:10:31 EST 2003 | neil
Remember the gold is only deposited to provide an air barrier so that the nickel does not oxidise. Normally the gold is absorbed into the solder joint so that the solder forms a joint with the nickle. It is not unusual to see gold remaining on pads i
