Electronics Forum | Thu Sep 16 18:59:14 EDT 2004 | Carol
Thanks Everyone, the information was very useful. We use 7095 as a bible. A-610 6.5.3 doesn't allow for any solder balls not entrapped/attached etc. so we will look again at plugging/tenting both ends of the via. We ran into the problem of the mask
Electronics Forum | Sun Dec 15 22:31:43 EST 2002 | craigj
Has anyone heard of vias cracking (barrel from pad) when being wave soldered. Was told this was a big problem by contract pcb designer, he always tent vias because of this. The reason was that the solder filling the vias caused stressing and then sep
Electronics Forum | Fri May 28 13:19:31 EDT 2021 | cbart
I can't see the image very well, but from what i see it looks like oxidation. looks like an ENIG finish on the board, possibly a plating issue from the bare board house, thin gold or the nickle is to thick. one other question i would get an answer t
Electronics Forum | Thu Jun 03 18:51:25 EDT 2021 | emeto
It seems like some oxidation that flux is able to fix on the soldered pads. Is it looking like this before you reflow?
Electronics Forum | Mon Dec 16 09:36:54 EST 2002 | russ
I have never had this problem. It sounds like you are right in imagining that there must have been a bad supplier of PCBS or an inadequate design rule being followed, or a very bad wave process to have this cracking over wave solder. Some books requ
Electronics Forum | Mon Dec 16 10:54:48 EST 2002 | davef
Knee of barrel and pad crack: Caused by thermal stress during soldering, because epoxy expands in the "z" 3X more than "x" or "y" which are restricted by the fiber. Related to: * Design of pads too large relative to hole diameter * Temperature at o
Electronics Forum | Tue Feb 23 08:46:11 EST 2021 | dianau
Hello, I have a topic with vias discoloration(that's what supplier said) and I don't know if it's an corrosion problem or something else. I believe that maybe the PCB's are not storage properly. I must mention that aren't any problem at soldering. D
Electronics Forum | Mon Feb 08 20:09:49 EST 2010 | davef
Woody: Consider using test BGA with no chip in, but daisy chains that you can monitor. After soldering, run environmental tests and follow with electrical tests to determine if the product concept is good enough.
Electronics Forum | Thu Sep 16 15:01:13 EDT 2004 | russ
You may want to either open up the bottom of the vias so they will not "volcano". Or you will want to seal both sides. It never works having one side of the vias masked and the other open with HASL. Russ
Electronics Forum | Sat Sep 18 08:26:10 EDT 2004 | davef
Carol: If you would have problems both covering the via and keeping mask from the BGA pads, maybe you via are too close to the pads. Maybe some of the IPC pad design guidelines would help.
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