Electronics Forum | Tue Jul 17 15:13:53 EDT 2001 | mparker
Dave - I agree that the U shape for QFP's sounds a bit whacked, for the reasons you state. It may work OK for larger pitchs but then again there are a myriad of fixes that work before resorting to U shapes. With the U shape removing paste from under
Electronics Forum | Mon Jul 16 21:25:26 EDT 2001 | davef
Sure, use of U-shape apertures is another way to reduce the amount of paste that you apply. That and similar schemes mentioned in the article are not a function of the flux used. We have used U-shaped apertures for MELF and mini-MELF. They are sug
Electronics Forum | Mon Oct 27 14:15:47 EDT 2008 | hussman
So you passed a BARE board thru the oven and got solder balls?
Electronics Forum | Tue Feb 29 10:14:02 EST 2000 | Robert Hartmann
My company is just getting into the flip chip packaging arena. We are putting in a prototype/small volume wire bond PBGA line. We have some questions with regard to choosing solder balls and cleaning of flux. 1) Is there a formula for the shrink
Electronics Forum | Tue Feb 29 10:14:02 EST 2000 | Robert Hartmann
My company is just getting into the flip chip packaging arena. We are putting in a prototype/small volume wire bond PBGA line. We have some questions with regard to choosing solder balls and cleaning of flux. 1) Is there a formula for the shrink
Electronics Forum | Thu Oct 23 23:38:48 EDT 2008 | pathakvj
We have 8 layer HASL PCB. We saw molten solder blobs / balls on op side of assembled PCB. (to check, if this was a bare board problem), We passed bare board as received thru, SMT reflow oven and saw solder balls on top side of board. What could be th
Electronics Forum | Sat Oct 31 10:56:16 EST 1998 | Dennis Barry
| I finally got my problem figured out on the bridging, the | only thing I'm finding is that I notice some litlte solder balls on the bottom of the board. Is that normal? Is that why I'm getting bridges? Has anyone came across this problem and pass t
Electronics Forum | Fri Oct 24 06:55:48 EDT 2008 | clampron
Good Morning WS, If you experieced the solder balls after reflow of a bare board through the oven, then the source of the solder is either the oven or the board. I have had boards with untented via's that were HASL'd that had entrapped solder and fl
Electronics Forum | Fri Oct 30 18:08:59 EST 1998 | Dave F
| I finally got my problem figured out on the bridging, the | only thing I'm finding is that I notice some litlte solder balls on the bottom of the board. Is that normal? Is that why I'm getting bridges? Has anyone came across this problem and pass t
Electronics Forum | Mon Nov 02 17:45:46 EST 1998 | ChrisK
In my experience, solder balls are normally caused by only a few things. In order of likelyhood: 1) Water based fluxes (VOC-Free)not having the water carrier completely dried from the board before going into the solder. I.E, too fast conveyor spee
