Electronics Forum | Thu Feb 15 07:04:59 EST 2001 | CRAIGS
Antonio, one possibility I have seen before on BGA shorts was due to chain slippage on the reflow oven due to worn gearing, the slippage was not severe enough to move other SMT devices but was enough to disturb the molten solder under the BGA
Electronics Forum | Wed Feb 14 16:03:54 EST 2001 | lileubie
Do you have a stencil wipe step after every six boards? If so, the wipe either automatic or manual needs to be optimized. Either less solvent or more time for the solvent to evaporate off.
Electronics Forum | Wed Feb 14 16:45:01 EST 2001 | Antonio
I'm sorry, I should clarify. The average is one out of six boards. It's not consistant as to how many are good before a really bad one. Sometimes two in a row, sometimes ten. Right now we are wiping every 2 boards. Antonio
Electronics Forum | Wed Feb 14 15:55:31 EST 2001 | Antonio
Fellas, Here's the deal. We're getting shorts on a limited number of boards under the BGAs; about 1 out of 6 boards. The thing is that these boards have about 10 BGAs on them. On the one out of six boards with shorts, the shorts are everywhere and
Electronics Forum | Wed Feb 14 21:14:45 EST 2001 | davef
BGA Shorting 1 Damaged mask in between the BGA pad and via on the substrate. 2 Poor print registration. 3 Poor via segregation from the pads? Are they tented or is there just a dam in between? 4 Review the profile. You can run into a number of p
Electronics Forum | Thu May 15 07:37:49 EDT 2003 | pteerink
Have seen similar circumstances a couple times. Possible causes: 1) PCB defect - remove the BGA and inspect/test the PCB for shorts. ( trace short, layer short etc ) 2) PCB defect that only shows up when the BGA is populated - a short somewhere o
Electronics Forum | Fri May 16 09:37:43 EDT 2003 | russ
Could we be seeing trapped water or flux underneath the BGAs? Russ
Electronics Forum | Thu May 15 11:50:19 EDT 2003 | mantis
we have seen something similar,at the edge,sof the Bga the tracks were shorted with some burr and excess gold. It was very hard to find but it was root caused back to the BGA manufacturing process.
Electronics Forum | Thu May 15 03:14:33 EDT 2003 | Hon Choi
Dear all, Not sure if you have this experience, but we've been seeing shorts on the BGA's from a widely known supplier "i". These shorts can not be found on the X-Ray, and when we remove the BGA, the component is ok. We peeled a few BGA's off, and
Electronics Forum | Sat May 17 02:13:43 EDT 2003 | Hon Choi
Thanks all. We are using no clean, so the boards are not washed. That would eliminate the trapped water issue. We would check the PCB after dismounting the BGA, and the short would not be found. When we place another BGA on the board, the board w
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