Electronics Forum | Wed Dec 20 07:54:13 EST 2006 | davef
We pipe a nonfunctional witness mark on every board. We inspect the witness mark. Ours consists of six pairs of dots arranged in a five-pointed star pattern. Again, consider paying attention to the cause of the problem. Your machine is NOT operat
Electronics Forum | Thu May 04 13:35:28 EDT 2017 | jmathis
Hello All, I was given an assembled flex circuit PCB and asked how the board was depanelized as there are no view-able witness marks that I can see. Any ideas? Thanks in advance on any insight to depanelizing without leaving witness marks on the F
Electronics Forum | Mon Jun 04 10:40:37 EDT 2012 | davef
I'm not aware of any such stipulation about witness [probe] marks for assembled boards, per se. Certainly, witness marks should not affect the intended performance of the assembly, you know, like damaging the solder connection or smudging solder mate
Electronics Forum | Mon Jun 04 23:52:57 EDT 2012 | rway
Actually, if you experience lack of witness marks, you probably have a problem. Witness marks are OK and will not affect your assembly. I assume this is an SMT assembly we are talking about, in which case, this is what your test pads are for. You
Electronics Forum | Tue May 15 09:01:41 EDT 2001 | davef
Stephan makes good points. While monitoring the temperature in the plant is good, it might be more appropriate to measure the temperature in the cabinet of your dispensor. A sure indicator of temperature change is process changes over time. Consid
Electronics Forum | Tue Nov 07 11:14:11 EST 2000 | Adam
There is a variation on the pins that come through on the other side. The pins that are deforming are roughly half the size of those which aren't deformed.There are no witness marks on the pins that are deformed, suggesting that the pins aren't fouli
Electronics Forum | Wed Dec 06 08:29:50 EST 2006 | David
Hi Pavel, We regularly use over printing on a multitude of problem parts including fine pitch QFP's. In an Automotive Environment the only thing you can change without a mountain of paperwork is the stencil. best way to work out how much you can get
Electronics Forum | Tue Jul 13 14:36:55 EDT 1999 | JohnW
| I am examining cut & form PTH component prep equipment to help in our manual PTH insertion process. We need the ability to process both axial & radial with snap-in and stand-off capability. Low volume with the ability to feed bulk, T&R, or Stick. |
Electronics Forum | Fri Aug 10 13:52:58 EDT 2001 | davef
When you say that glue viscosity changes for lot to lot, is this LOT TO LOT of your product OR Loctite�s product? And when you say that glue viscosity changes, what do you mean [eg, increase by � , decrease by � , er watt?]. What specifically is th
Electronics Forum | Wed Jan 05 18:25:29 EST 2022 | cyber_wolf
Its kind of nice to be able to put a dirty stencil in the cleaner and get a dry clean one out. That pretty much points to the spray units with a dry cycle. Things to consider, chemistry consumption, how your stencils are bound, maintenance,and of c
