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 | Thu Jul 17 10:56:50 EDT 2003 | James
COULD SOMEONE PLEASE TELL ME OF A WAY TO CLEAN THE OXIDIZATION OF OF WHITE TIN PADS, I AM GETTING ALOT OF DEWETTING PROBLEMS. AND I CONCLUDED THAT ALL THE BOARDS WITH WHITE TIN ARE HAVING THE SAME PROBLEMS. THANKS FOR THE INPUT.
Electronics Forum | Thu Apr 15 17:48:15 EDT 2004 | davef
When we see dewetted solder on pads, we sprint to get sections done, in order to determine if over-exuberant pumice scrubbing by the fabricator has buried material in the copper.
Electronics Forum | Fri May 14 11:17:42 EDT 2004 | Ashok Dhawan
I am having coating adhesion problem with flex circuits. The cover plate material is KAPTON or Poly imide. The conformal coating material used is humiseal 2A64. The boards are cleaned, measuring less than 4 microgram Nacl per sq in. against acceptabl
Electronics Forum | Tue Jun 07 16:19:58 EDT 2005 | davef
Q1) How to identify on good or bad ICs lead that could contribute to dewetting? A1) Distinguish between good or bad IC that could contribute to dewetting by testing for solderability, according to J-STD-002. Q2) What actions that must be taken in fa
Electronics Forum | Fri Jun 10 13:15:17 EDT 2005 | chunks
Hard to tell, but it looks as if this LED has no side termination, so it may only look like dewetting. If everything around this part is reflowing, I'd bet that's all this is.
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 | Tue Oct 31 13:22:51 EST 2006 | realchunks
Are you using Houdini brand paste? It really depends on the part and pad size, but I kinda doubt that you�re paste is disappearing during the 2nd reflow. Do a side by side comparison of first pass versus second pass reflow and show your operator.
Electronics Forum | Tue Oct 31 13:32:16 EST 2006 | bobsavenger
yeah, that's what I've explained to them is that it is not going to disappear. Currently they are in the process of running this PCB again and I'm going to do the side by side comparison. Thanks for the input.
Electronics Forum | Tue Oct 31 22:56:23 EST 2006 | davef
So at incoming inspection, what are the results for your "dip & look" solderability testing [IPC/JEDEC J-STD-002A] of the specific problem component?
