Electronics Forum | Thu Feb 18 21:20:13 EST 1999 | Ernie Flamont
During inspection and test we find leads which do not get soldered. Some are because of insufficient paste, but with others everything looks right. This will only happen on 1 to 2 pins, and it is not isolated to a specific type of ic or location on
Electronics Forum | Sat Aug 21 15:07:34 EDT 2010 | jry74
I have a problem with solder bridging between IC leads, especially fine pitch leads. If we lessen the apature ratio and/or decrease stencil thickness, I have more of a chance for unsoldered or insufficent joints. I am looking for any information th
Electronics Forum | Mon Aug 23 13:59:18 EDT 2010 | swag
Under a scope, make sure the PCB has soldermask between pads.
Electronics Forum | Mon Aug 23 17:43:18 EDT 2010 | davef
SAG: Questions on solder mask webbing with fine pitch parts are: * What is the minimum pitch that you can use webbing between fine pitch pads? * What solder mask do you use?
Electronics Forum | Wed Sep 01 08:05:28 EDT 2010 | sachu_70
Solder mask between pads in case of fine-pitched device footprint may not be a practical solution to implement. Cheers !!!
Electronics Forum | Mon Aug 23 03:12:57 EDT 2010 | grahamcooper22
Possible route causes of bridging on fine pitch ICs are; too much paste (stencil aperture wrong), poor print quality (paste smudges during printing), pcb pads not flat depending on the solderable coating, paste has poor cold slump properties, too muc
Electronics Forum | Mon Aug 23 14:09:56 EDT 2010 | davef
Similar to Coop's comments, above ... Bridging: * Mis-placement: misplaced components, high placement force mushrooms paste * Too much paste: HASL thickness, lead finish, poor underside support, poor underside wipe frequency, printing with too lar
Electronics Forum | Fri May 28 07:37:52 EDT 1999 | Steve Cheung
Yes l know this problem keeps cropping up on the forum but l've missed some of the follow-ups. Our problem is that the lifting only occurs on 3% of production so actually detecting an improvement is difficult. We're actually having to inspect 144 p
Electronics Forum | Tue Sep 16 17:03:34 EDT 2014 | rangarajd
We have an issue with solder wicking up the leads/ inside terminations on an SMT connector. The solder coverage is sometimes over 50% of the connectors inside pin length. The terminations are gold plated. Is there an IPC spec for acceptability? Plea
Electronics Forum | Tue Feb 23 09:21:15 EST 1999 | Steve Schrader
| During inspection and test we find leads which do not get soldered. Some are because of insufficient paste, but with others everything looks right. This will only happen on 1 to 2 pins, and it is not isolated to a specific type of ic or location o
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