Electronics Forum | Thu Jul 15 14:01:15 EDT 2004 | nanref
WERW HAVING PROBLEM IN OUR PRODUCT SINCE WE STARTED USING A LEADFREE SOLDER PASTE..REJECTS OF TOMBSTONING IS SO ERRATIC...HOPE YOU CAN GIVE SOME INPUTS HOW TO CONTROL THIS..WHAT IS THE POSSIBLE CAUSE?THANKS
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 | Fri Jan 25 19:01:35 EST 2013 | hegemon
My first guess is that the plating in the barrel (via) has failed and allowed laminate/epoxy egress into the barrel and out to the surface of the board. Just a guess based on the picture.... 'hege
Electronics Forum | Fri Feb 22 16:32:56 EST 2013 | davef
Jorge: I took this total posting to several fabs at IPC APEX. None was satisfied with the answers you receive from your supplier or the Forum members. They suggested that you get your board analyzed. They were surprised that your supplier didn't in
Electronics Forum | Sat Jan 26 21:33:39 EST 2013 | sarason
Looks like you have a carbon black process that isn't quite plating to completion, pin prick size holes have remained in the plating. When dipped in an etchant (ie any acid or H2O) the holes grow and they leak carbon. This may be more of a problem th
Electronics Forum | Fri Jan 25 14:20:31 EST 2013 | jorge_quijano
Hi there, I have a new product today, after reflow oven I've seen a black stain coming from various holes, they can be cleaned with a tissue but some of the contaminant remains inside, we are using Sn63Pb37, the stains are far from soldering areas, t
Electronics Forum | Fri Apr 12 15:10:00 EDT 2002 | jsherrow
IMHO it's caused by three things: 1) placement 2) placement 3) placement
Electronics Forum | Thu Apr 11 20:35:22 EDT 2002 | davef
Messy. Messy. Messy. Consider gluing these components, until you control your process. It is unclear to us that a single factor drives these defects, but multiple factors that need to be tuned to work well together. PAD DIMENSIONS * Some SM-782 pa
Electronics Forum | Tue Dec 12 08:44:27 EST 2000 | Wolfgang Busko
Another theory just developed in this very moment is that the glue did for what reason ever become "liquid" to a certain degree allowing gravity to do what gravity normally does but only to a certain point where this bubble-gum-like state stopped ( w
Electronics Forum | Mon Dec 11 03:46:14 EST 2000 | JohnW
I have to say I've never heard of anything tombstoning over wave, I've seen issues where the glue dot is too high or off to one side creating a poorly seated component that has too big a gap between pad and endcap(and hence an open), but never a tomb
