Electronics Forum | Tue Dec 31 10:06:37 EST 2019 | emeto
This one is easy. Go to 5mil stencil and reduce apertures in width. try to have 10mil aperture width and 10 mil distance in between. If you give us numbers we will be more precise.
Electronics Forum | Mon Jun 21 01:32:20 EDT 2021 | yaxindatech
We can reproduce a prototype for you, if the defect can not be repaired. We are a PCB manufacturer in shenzhen China. It can be manufactured as a sample order in 2-3 working days.
Electronics Forum | Thu Jun 06 15:55:28 EDT 2002 | arzu
I agree with the others and experienced the problem myself this week. Solderballs at the side of the chips. I looked at the board and found that the chip is pressing the paste away too much. This in combination with our quite big pads(and stencilaper
Electronics Forum | Tue Jun 04 17:21:22 EDT 2002 | jasonfang
I found solderballs are around chip components (on one side of middle area), I checked gerber data, solder paste of aperture on the stencil for these chip components have 5% reduction to solder land on PCB, shape of solder land are square, not home p
Electronics Forum | Tue Jun 04 20:34:28 EDT 2002 | russ
Jason, Excessive thermal ramp rates, misprints, improper pad design, paste type, placement pressure, all can cause solderballs. Do the pads on this board meet IPC 782 criterias? I have found that too much pad underneath component can cause this. A
Electronics Forum | Thu Jan 02 10:31:48 EST 2020 | slthomas
It is strange that you're having issues while using the same process parameters (including stencil) that worked successfully before. It doesn't guarantee that it's not one of those parameters changing in a manner that's not apparent, but it does sugg
Electronics Forum | Thu Jan 02 11:35:30 EST 2003 | Richard
Cleanliness test � �Area Grid Arrays�. Evaluation of residues� resistivity in a specific location on the board. (As compared to �Solvent Extract� evaluation.) We are: SMT assembly, using standard �water soluble� process with micro BGAs (example: C
Electronics Forum | Tue Oct 26 08:41:56 EDT 2004 | Bob R.
When we first got into BGAs on ENIG we were getting joint cracking at in-circuit test. The joints were breaking in the Sn-Ni intermetallic. We did a lot of pull testing while working with our board suppliers and our conclusion was that pull testing
Electronics Forum | Mon Nov 15 15:27:48 EST 2004 | davef
In creating your solder balls, consider printing or dispensing solder paste on the pads of the LGA and then reflowing the paste.
Electronics Forum | Mon Nov 19 05:49:44 EST 2001 | Cheng
The BGA solder ball composition is 62/36/2 Sn/Pb/Ag, does any problem exist for the solder joint reliability? And what is the difference on SMTA process between this and the normal 63/37 ball?
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