Electronics Forum | Thu Sep 03 10:39:27 EDT 1998 | Rich Weaver
I am in need of possible causes and solutions to capacitors that are failing in the field. Are there issues in our process that need to be checked? Some people said the problems are due to improper storage. Others say it is thermal stress in our
Electronics Forum | Fri Aug 06 07:16:36 EDT 2004 | davef
When moisture outgasses through plating, it continues through the molten solder, causing a meak solder connection. There's another issue with thin plating that we haven't focused on in this thread. If plating is thin, the stress on the barrel of a
Electronics Forum | Fri May 12 12:07:10 EDT 2006 | solderiron
The kester better known as KY'd Sn/Cu has more copper intermetallic growth over time, dissolves copper from the board faster so repairing and touchup can damage board. Bridges more than SN100c. Does not thermal cycle well. Has shrink cracks that can
Electronics Forum | Thu Jul 06 15:55:19 EDT 2006 | Vad
guys pls. comment which is better based on actual experience and not on the selling side of it..thanks a lot..people... one of my supplier said SACX is better but I need proof...living....he claim belo: 1. Better hole fill 2. Higher wetting force 3
Electronics Forum | Sun Dec 02 20:02:23 EST 2007 | chs
Hi, There are QFN 32,40,48 pins with middle pad. Body size are 7x7 and pitch 0.5mm. I means as compared to 2 sided package, QFN are easily damaged by external mechanical / thermal force. Phenomenon observed are mold cap open which further caused wire
Electronics Forum | Fri May 04 11:47:56 EDT 2012 | pctech
Hi, It's not advised to hard-down the re-flow oven.There are two reasons for that ; extreme thermall difference in temp. will cause chain and drive shafts to warp and T/C's to crack.Let your "cooldown" profile do this safely within 45 mins. to an hou
Electronics Forum | Wed Jul 04 12:18:14 EDT 2012 | davef
Phil is correct in his description of proper rework technique. Possible explanations of the reason for popping of your BGA are: * Thermal cycling of components cause them to flex on a different point in the cycle that the board possibly resulting in
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 | Mon Aug 10 12:58:04 EDT 2020 | SMTA-64386637
We have found Acrylic CC under QFNs is a failure mechanism in thermal cycling. The coating acts as a wedge and causes solder joint cracks. We do not coat QFNs. To enhance reliability we have the vias plugged with solder mask. This eliminates some
Electronics Forum | Wed Feb 02 20:53:34 EST 2000 | Dave F
Dennis: Several points: 1 If you're talking AlphaLevel process (?): � Good solderability, as HASL, even no-cleans bite well. � Planarity, uniform deposit, no bridgin� of FP. � Doesn't store as well as NiAu ... LT 6 months sealed � Very sensitive t
