Electronics Forum | Wed Sep 26 12:16:44 EDT 2012 | bwjm
Hi Guys,recently i am facing an issue. Refer to the attached photo. This PCB is high RF speed, gold immersion single layer. After reflow, my solder seems to have black stains on it. I tried with SAC305 paste water soluble and no-clean, both results a
Electronics Forum | Fri Feb 01 03:03:08 EST 2002 | madreindeer
Hi, That is very common in WS pastes.It is white residue (Salt) Usually it�s not dangerous it only looking bad. I think best way would be contact your paste supplier and they should know what would take a stain off if not, change supplier. There i
Electronics Forum | Sat Jan 19 02:25:37 EST 2002 | ianchan
Hi, Have a board run, using 63/37 Water Souble (WS) process. during the reflow setup time, we had unsolder issues on a leadless bump chip carrier (BCC) IC level package. To rectify the unsolder rejects, we adjusted the reflow time from 25-55sec into
Electronics Forum | Sun Jun 10 23:49:17 EDT 2001 | Robert Sykoh
No-clean is definitely a cheaper process. It will eliminte cleaning. Some issues associated with no-clean are: -- the flux stain left behind on the PCB will create a cosmetic issue. You may want to seek advice from your customers. -- next, the flux
Electronics Forum | Wed Dec 19 01:17:13 EST 2001 | ianchan
Hi Experts, I need help here, advice appreciated from all... Production is running a Lot of flex-circuit PCB, through the SMT line, with 0402 components. The flex-PCB is taped to FR4 support "pallets" when processing thru' the SMT P&P m/c. We use
Electronics Forum | Wed Dec 19 02:24:40 EST 2001 | ianchan
Did I mention, we tried to use the same WS flux formulae to brush-cover the affected flex-PCB pads, and subject it to another round of water-wash, followed by oven-baking, and it still doesn't help abit? Oven bake : 100 deg-C, approx 15~30mins (manu
Electronics Forum | Thu Dec 20 19:45:41 EST 2001 | ianchan
Hi M.Parker, thanks for the suggestion, and tips shared from you... Merry Christmas!
Electronics Forum | Wed Dec 19 11:52:24 EST 2001 | mparker
Have you tried to polish the flex with an ESD camel hair brush? The residual films - are they organic, left over from the water? Maybe try some TSP - tri-sodium phosphate, it's a mildly caustic detergent. A thorough rinse would be needed after using
Electronics Forum | Wed Jan 02 12:00:44 EST 2002 | mparker
Thanx and the same wish for you as well. and I did think of the toothpaste angle after my last posting, glad you found something that worked.
Electronics Forum | Tue Jun 07 10:24:59 EDT 2016 | davef
wlsmt: You’ve got to help us out here: * Why did you apply solder paste to capacitors prior to water washing the PCBA [where the caps were attached?]? * Did you reflow the Alpha WS-609? * How is the Alpha WS-820 involved in this? * Talk about the