Electronics Forum | Wed Aug 24 12:37:38 EDT 2011 | hussman
Hello all, We just got some board back from thermal shock and we found that several of the 2512 resistors opened up. Actaully the solder joint cracked away from the board. All other coponents look great. Boards were good before test. 10 layer bo
Electronics Forum | Thu Aug 20 07:11:25 EDT 2020 | sssamw
What your said looks like a acrylic coating thermal expansion causes small solder joint crack. Do you cure coating with heating, or heating after curing? Solder joint crack while you see resistor and QFN trouble? Clear and detail description of your
Electronics Forum | Tue Feb 23 10:33:40 EST 2010 | andrzej
To prevent cracking SMD components near the edge of PCB you should use guillotine for V-cut groove. Other solution is redesign panel of PCBs and in critical areas you should mill along the outline instead of V-cut, but if you choose this way probabl
Electronics Forum | Thu Mar 14 09:07:26 EST 2002 | cfraser
I can not tell you what the actual stress limits are. I can tell you that de-paneling PCB's by hand is a very poor choice. I have seen numerous accounts of cracked caps, resistors, and LED�s due to incorrect de-paneling procedures. I would recommend
Electronics Forum | Mon Nov 23 19:20:18 EST 1998 | Kevin
A buddy of mine has problems after depaneling double sided pre-scored PCB's. Resistors near the edge, after put into the slice and dice machine contain micro cracks. He's checked for them before and after depaneling. We figure it is the sectioning
Electronics Forum | Mon Nov 18 20:30:39 EST 2019 | alanyang
The chip resistors are placed on the edge of the board, but the board has no or enough waste tabs. When de-panelizing, the bits may contact and break them. You can use a smt carrier, or add waste tabs in your next assembly manufacturing.
Electronics Forum | Tue Feb 16 20:35:53 EST 2010 | davef
While you're waiting for others to reply, search the fine SMTnet Archives to find threads like: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=29040
Electronics Forum | Fri Apr 11 11:26:09 EDT 2003 | Brian W.
Cracked capacitors usually are not found at ICT. Unless the cap is completely cracked, the capacitance may not change much, and the usual failure mode is a leakage current. This is usually only seen in ESS type testing, when temperature and humidit
Electronics Forum | Thu Jan 21 18:11:24 EST 2010 | colormaker
I have a strange problem with 1208 resistors flipping off placed position. I have the same reflow settings that I have used for years with the same solder paste. PAste is only a few months old and it was used just 1 week ago without problems. Some re
