Electronics Forum | Fri Jul 12 22:15:56 EDT 2013 | ericrr
Sorry to build up your hopes. The latest thing to hit the air ways at work, I was accessed of fiddling with the oven settings, because there were reports of "cracked joints" there was no mention of where the cracks were, cracked at the pcb or cracke
Electronics Forum | Wed Jan 07 17:34:52 EST 2015 | duchoang
Customer puts our board to thermal test. Test cycle is -55c to 85c, repeat cycle in 15-20min. After 600 cycles, lot of TSOP joints are cracked, leads lifted. There are reasons such as thin PCB, mechanical impacts, warped PCB... My question is, how lo
Electronics Forum | Fri May 31 10:15:30 EDT 2019 | davef
Major sources of crack in the solder connection after thermal cycling are: * Thermal heating caused by differences in thermal expansion between the board and the component * Lead-free solder is more rigid and brittle than eutectic solder in simila
Electronics Forum | Sat Jun 01 04:22:24 EDT 2019 | gregoryyork
Depends on lead free alloy choice as well
Electronics Forum | Mon Aug 01 06:59:02 EDT 2005 | Joseph
Dear all, We observed visible micro crack at top side of solder fillet during lead free wave solder process. We did not see any visible micro crack at bottom side, and it always located at joints of transformer. Any input be much appreciated. Best
Electronics Forum | Wed Aug 10 10:41:23 EDT 2005 | patrickbruneel
Bob, Great theory if you're selling SN100C, but I have to disagree that an alloy being 4�C off eutectic will cause cracks. When a solder joint exits the solder wave, there is an immediate drop in temperature of 100�C. so being off 4�C is irrelevant.
Electronics Forum | Mon Aug 01 20:02:20 EDT 2005 | Joseph
We use SAC305 and top side particular joint temp. is 110 deg C, and the terminal finish for that particular lead is pure tin. It look like hot tearing at the primary side of PTH.
Electronics Forum | Wed Aug 03 21:29:59 EDT 2005 | Ken
Yes, lead can promote fillet lift. In order to understand this defect you must begin looking at your lead frame mateials. some lead frames are more susceptable to this disorder. This is most likely a cte mismatch disorder. Lead contamination in
Electronics Forum | Tue Aug 02 22:49:55 EDT 2005 | davef
IPC-A-610D Section 5, shows a variety of photographs of: * Good lead-free solder connections * Lead-free soldering anomalies Hot Tear / Shrink Hole is one such anomaly. This shrinkage effect appears primarily on wave-soldered joints, but can also
Electronics Forum | Wed Aug 10 09:01:15 EDT 2005 | fctassembly
Hello Joseph, Sorry for the bad news but microcracking is a well known potential condition occuring with the SAC305 alloy. Microcracking is a condition being seen with many joints soldered with the SAC305 alloy. It is technically a shrinkage cavity
