Electronics Forum | Sun Aug 16 16:01:06 EDT 2009 | davef
White, lead free * Taiyo America PSR-4000 LEW1 * Huntsman (formerly Vantico, formerly Ciba Geigy) Probimer 77 white solder mask Also, search around LEDs Magazine [ http://www.ledsmagazine.com/ ]. White solder masks are often used as a reflective ba
Electronics Forum | Fri Sep 18 09:25:16 EDT 2009 | ysutariya
There's not really a good answer except that I think that the industry wasn't really prepared for such an increased use of white soldermask combined with the importance of using the white as a reflecting surface. Essentially, the resins commonly u
Electronics Forum | Thu Apr 15 14:09:48 EDT 2010 | richardli
We found stains on the boards come out of reflow oven. The board itself color changed to yellowish from white . We understand discolor soldermask due to high temperature. This can be acceptable by our customer not the stains. The stains look like wa
Electronics Forum | Fri Jan 04 06:28:27 EST 2019 | ameenullakhan
Hi, We are observing solder joint discoloration ( yellow color appearance ) in one of assembly after secondary reflow run. Please provide your valuable feedback. Solder paste : water soluble lead free Alloy : SAC305 Flux : ORM1. Please provide v
Electronics Forum | Mon Apr 19 20:49:13 EDT 1999 | Dave F
| Netters, | | When I reflow a PCB there is a discoloration of silkscreen and mask. It appears if Profile is too hot! But I dont think so, maybe I'm wrong? | | 1. Kester 293 no clean | 2. 2.1 C/s for 30s to 150 C | 3. .5 - .7 C/s for 60s to 185
Electronics Forum | Tue Aug 22 16:13:08 EDT 2000 | Dr. Ning-Cheng Lee
FR-4 will be OK for small products such as cellular phones. Here the temperature gradient across the board may be 3-4C only, and the board temperature can be well controlled. At temperature above around 245C, the discoloration and delamination may be
Electronics Forum | Mon Jun 18 19:57:40 EDT 2001 | Gil Zweig
Dave: You pose a very good question. We have been in the electronics x-ray inspection business for 18-1/2 years and, to date, we have not received a single report of damage associated with x-ray exposure. However... we do see signs of long term x-ra
Electronics Forum | Fri Oct 29 10:02:28 EDT 1999 | John Thorup
Chris A lot of people have reported sudden, fab lot related problems with Ni/Au pads. These are usually characterized by a discoloration of the gold and called cheerful names like "black pad disease". This can be a process problem at your fab house
Electronics Forum | Mon Dec 18 04:03:30 EST 2006 | greg york
Good solvent wipe will normally show some discoloration of the same colour as resist, but not scientific enough as you cant gauge the amount coming off, ideally none. But is an indicator of the issue. I have been meaning to do a swab with an indicato
Electronics Forum | Fri Jan 19 10:43:28 EST 2007 | jimmyjames
You guys are all joking right?! There aren't any contaminates in your solder, the different colors on the surface are completely normal and even expected. The top layer of solder oxidizes and the structure of the surface resembles crystals, refract
