Electronics Forum | Tue Aug 25 13:30:35 EDT 2009 | rossi
It appears that the crack is between the paste and the ball. We physically pulled off the BGA by force and almost all the balls broke at the PCB. There was a thin layer of solder left on the pad. Maybe 1% of the balls stuck to the pad. I have attac
Electronics Forum | Fri Jun 23 14:10:01 EDT 2000 | Chrys Shea
Sounds like the mask to me. Had a similar situation a couple years ago. The mask wasn't fully cured, so it absorbed water that the preheaters couldn't dry out. When it outgassed at the wave, it caused a lot of micro turbulence that broke the surfa
Electronics Forum | Mon Mar 30 16:02:44 EST 1998 | Michael Allen
| We have successfully put .016" vias in .030" pads. | There is no issue with .030" solder balls, since | the actual volume of the .002" via in pad is small | compared to the ball+solder paste volume. | We did notice random bubbles where, apparentl
Electronics Forum | Wed Sep 08 17:49:19 EDT 2004 | gregoryyork
Knock off some balls and you may find it has a flat bottom to it were it has mechanically stuck to the solder resist usually seen under 60X magnification. Common with Liquid photoimageable resist (I know again) Best way to check resist cure is to pay
Electronics Forum | Tue May 18 15:36:18 EDT 1999 | Tony
| | | What is the best way to re-ball a BGA? Who has the best system for doing it? | | | | | I'm using our SRT rework stuff to reball in house - when necessary. Of course, we only do this for protos and test boards. We use a standard micro-stencil,
Electronics Forum | Tue Mar 17 07:32:10 EDT 2009 | davef
Solder ball acceptance: IPC-A-610, 6.5.3.1 & 12.4.10. Solder balls: 5 ball system: * No more than 5 balls per square inch (100mm2) allowed * Solder balls can not be greater than 5 mil (0.005in) (100um) * Solder balls cannot be less than 5 mil (100um)
Electronics Forum | Fri Aug 05 14:38:50 EDT 2011 | bandjwet
Does anyone know of a vendor able to perform ball shear testing services per JES stds? Thanks! BWET
Electronics Forum | Tue May 18 14:15:59 EDT 1999 | Scott McKee
| | What is the best way to re-ball a BGA? Who has the best system for doing it? | | | I'm using our SRT rework stuff to reball in house - when necessary. Of course, we only do this for protos and test boards. We use a standard micro-stencil, after
Electronics Forum | Tue Dec 29 11:40:24 EST 1998 | Michael Allen
I don't have answers...just comments. We're just starting to assemble CSPs on protos, and I've got the same concerns you have. The MicroBGA package I'm working with has a ball diameter of 0.325mm (0.0128") and a standoff of just 0.010" BEFORE solde
Electronics Forum | Wed Nov 14 20:28:24 EST 2001 | davef
Not to worry. Just run the boards through the cleaner. It will remove all the solder balls. The gross filter on your washer will collect all the solder balls. Coo eh? ;-) How to cure SM? Is your mask UV, er thermal? After learning the type, you
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