Electronics Forum | Fri Nov 22 08:57:56 EST 2002 | davef
Q1: What do you mean by "if the board is manufactured properly"? A2: If the epoxy is noy cured prooperly, for instance, the copper will not be well attached to the glass. So, peel strength will be lower. Q2: I don't believe that the peel off/or lif
Electronics Forum | Thu Nov 17 20:23:55 EST 2005 | davef
We're with your customer. We believe inner layer separation is not linked to a heating excursion. What you are seeing is separation between the hole wall and the copper plating in the barrel of the hole on an unstressed PTH. Although, it's possibl
Electronics Forum | Wed May 21 04:50:51 EDT 2008 | aj
Hi all, We had similar problems a while back. Boards would fail at test but if you applied pressure to the BGA they would pass. Turned out that during the PTH assembly process the Operators were flexing the cards during the insertion of an Oupin C
Electronics Forum | Mon Jun 16 12:06:52 EDT 2008 | realchunks
Seen this with our old board house. The uncured board is causing your problem. Hard to catch, but looks like you have all your ducks in a row. We presented the exact same thing to our board house, and naturally they blamed our process, handling, a
Electronics Forum | Tue Aug 01 09:42:07 EDT 2000 | Gary
The Technical Services Group at Alpha Metals has spent a fair amount of time looking at wave soldered Pb-free connections. We too have observed fillet tearing, fillet lifting, and pad lifting. I have concluded that without major changes in the mate
Electronics Forum | Fri Jun 18 20:29:39 EDT 2004 | Ken
The problem is lead enrichment regions forming in the hottest part of the joint. The lead pool is the weakest part of the (SMT) joint. In TH interconnects hot tear or pad lift can result. I have recently seen this first hand.
Electronics Forum | Wed Feb 10 10:25:24 EST 2016 | capse
Akrometrix is a company here in Atlanta that measures surface topography at reflow temperatures for the PCB and component. They have software that overlays the two sets of data to look for warpage problems. They offers this as a service as well as se
Electronics Forum | Fri May 09 08:27:35 EDT 2014 | emeto
REduction of center pad is the key as well as the stencil thickness. Having too big opening on your stencil will sometimes lift the part from the pads. Always try to make windowpane and shoot for about 60% of the thermal pad to be covered as start p
Electronics Forum | Tue Nov 01 09:00:07 EST 2005 | russ
Is an RQFP a Qfp with the center pad for heat dissipation? If so, you may be shifting when this center pad reflows and lifts the part.
Electronics Forum | Tue May 20 17:09:13 EDT 2008 | davef
Sorry, we didn't do a good job of understanding your question. For more on delamination, look here: http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=54655 ... but we're not so sure that this is a straight delamination issue, because: * One
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