Electronics Forum | Fri Oct 31 09:26:08 EDT 2014 | rgduval
I do not recommend ever leaving the top of a via-in-pad open. Cap the via in the pad. Leaving it open for "solder to stuff the hole" causes issues in assembly, notably insufficient solder due to vampirism (the solder wicks into the via, rather than
Electronics Forum | Thu Mar 02 15:20:13 EST 2000 | Glenn Robertson
Dave - You certainly have a good point regarding the multiple part numbers and board suppliers, but a rework process for black pad has been reported. See the SMTAI 1999 Proceedings article by Zequn Mei (page 407). It involves flux and solder wi
Electronics Forum | Tue Oct 17 14:40:04 EDT 2000 | Glenn Robertson
Jason - I have only one thing to add to Dave's excellent (as usual) information. Some time back we had a similar problem and we removed the dross bits with a soldering iron and solder wick. Yes, it's tedious and you have to look closely to be
Electronics Forum | Thu Mar 02 15:20:13 EST 2000 | Glenn Robertson
Dave - You certainly have a good point regarding the multiple part numbers and board suppliers, but a rework process for black pad has been reported. See the SMTAI 1999 Proceedings article by Zequn Mei (page 407). It involves flux and solder wi
Electronics Forum | Thu Apr 10 11:57:19 EDT 2003 | stepheno
We recently had to replace some BGA's. The replacement ones did not work, and when removed there was residue. Unfortuneatly I didn't get a chance to see the residue. It was described as "fuzzy and grungy". The pads had been cleaned with solder wi
Electronics Forum | Mon Sep 22 16:00:43 EDT 2003 | Joe
Two BGA replacements (same location) and throw the card away is the rule we are following. Experience has taught us that anything beyond this and you'd be pushing it - specifically when your new PBGA's price is above $20.00. The biggest concern is
Electronics Forum | Fri Mar 04 11:30:46 EST 2005 | Steve
Is anybody using via-in-pad under a BGA successfully? Is this a specialized capability, or do most board houses have the capability to do micro-via's? How small does the via need to be in order to avoid solder wicking? I understand that in order for
Electronics Forum | Wed Apr 19 09:07:44 EDT 2006 | russ
Many times a pad that has no signal trace going to it will come off. It does happen from heat and time as noted before. Somtimes even the best rework person will remove them. If this can not happen in your situation I would recommend that you use
Electronics Forum | Fri Oct 03 16:22:38 EDT 2008 | alien
For plain old QFPs in small quantities, a temperature controlled heat gun + a decent soldering station can do the trick. In my case, Steinel HL 2010 E heat gun (handheld, but with a digital readout) to desolder. Clean up pads with solder wick. Solder
Electronics Forum | Tue Nov 13 09:32:28 EST 2007 | kpm135
For the simple fact that the via in the middle of the pad causes the solder to wick into the hole instead of flowing out across the pad and part. Thus cause insufficient solder issues.
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