Electronics Forum | Fri Sep 11 15:27:50 EDT 2015 | u4bga
Hi! We're noticing white spots on 2 PCBAs after the selective soldering & DI Wash processes. ----Facts---- 1) The marking is on all boards, irrespective of date code 2) It only happens on leads that have been selective soldered 3) The pattern of w
Electronics Forum | Wed Jan 25 07:24:31 EST 2017 | emeto
Hi, I used black marker before and it will works for a while, but it is not a permanent solution. Ask stencil house what kind of material and process they use to apply the black material. I think this operation might be done manually after the stenc
Electronics Forum | Tue Sep 27 08:22:27 EDT 2005 | Amol
I am using masking tape, the 3M high temp blue masking tape. the problem though doesnt seem to be related to the masking tap as i am seeing pin holes and eventual dewets over entire ckt board (its almost as if the board has chickenpox under black lig
Electronics Forum | Tue Oct 14 10:33:27 EDT 2008 | martinouk
We use masking tape - cheap as chips although you do have to replace it after washing. I have in the past used BLACK TAK from loctite. It was extremely expensive, and was supposed to be permenant. But after two/three washers through the cleaner it ne
Electronics Forum | Thu Feb 14 17:40:34 EST 2013 | jorge_quijano
PCB Supplier made an EDX anaysis, the found a chemical trapped in the holes, and some burnt burrs, according to what they say this stains are over the solder mask & silk, so they do not affect functionality.
Electronics Forum | Thu Jan 30 15:41:52 EST 2003 | MikeF
The easy part is to determine which parts should be coated. The harder part is making sure the parts that should not be coated do not get coated. I don't even want to think about the amount of labor and materials I've lost due to conformal coat get
Electronics Forum | Wed Sep 20 14:19:26 EDT 2000 | Jason Wraight
I am sure that this is a problem that will never be solved, but something that I am seeing in increased numbers. Often refered to as "Black Pads". After production, returns from the field coming back with contaminated pads under various components.
Electronics Forum | Wed Jun 19 15:13:56 EDT 2002 | dougt
I worked for a place that built flight boxes for the military and some comercial. As Russ stated, wrist straps were used where they could be used. In areas where they were in the way, i.e. room where they masked and sprayed the boards, they had the
Electronics Forum | Fri Oct 12 09:00:31 EDT 2007 | vargas_s
We've been using a series of relatively high durometer rubber molds to protect male headers from conformal coating here in our facility for quite a while now. They are black in color and are sold in strips that can be cut to desired lengths. Unfortun
Electronics Forum | Wed Jul 26 11:56:40 EDT 2017 | rgduval
Ah...the joys of subjective analysis! At a glance, these pictures look fine to me. Other than the IC's, which you've indicated were masked, and, maybe R12 in the last picture and CC1384 in the first image, coating looks uniform and well distributed
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