Electronics Forum | Thu Dec 19 16:15:26 EST 2002 | Dreamsniper
Hi Grant Petty, I read about your problem, You might have problem with the design. First on the pad. What is the diameter of the BGA pad in your PCB. We have the same size of PCB and we use 0.584mm Pad dia. and a 10% reduction on our aperture. We us
Electronics Forum | Tue Dec 17 18:16:18 EST 2002 | davef
Square apertures can have a larger area within the same space than a round aperture. You can buy IPC 7525 from IPC. The theory you are missing has to do with: * Aspect ratio * Area ratio Search the fine SMTnet Archives for background on these rati
Electronics Forum | Wed Dec 08 04:19:16 EST 1999 | pascal MATHIEU
I am working in electronic automotive industry and today we are facing to a very serious problem : if we want to use a PCBoard with a copper thickness of 90�m + fine pitch circuit (0.65mm, 0.5mm) the supplier(several) of the PCB has some trouble t
Electronics Forum | Mon Dec 16 10:23:42 EST 2002 | Grant Petty
Hi, I have checked the archives, but need some advise. We have a 256 pin 1 mm pitch BGA part of our boards, and we have having problems with paste release our of the holes for the BGA. We just cannot seem to get it right, and we have to keep the st
Electronics Forum | Wed Aug 31 11:02:28 EDT 2005 | Jason Fullerton
We are using one BGA that has 7 mil bumps on a 20 mil pitch. We use the manufacturer's recommended pad and aperature layout, which is an 11.8 mil square overprint on a 6 mil land. At 11.8 square, you need to use a 4 mil laser cut or a 5 mil e-form st
Electronics Forum | Tue Jan 30 15:30:17 EST 2001 | dason_c
Please check what is the actual pitch size. I found some of the designer use 15.7 mil pitch and no accumulate ie 15.7, 15.7 and 15.8...... Also, I recommended the pad width should be 10 - 11 mil for 0.4mm pitch. You can open the 10 - 10.5 mil aper
Electronics Forum | Wed Sep 18 06:53:05 EDT 2002 | CH
1) For solder short, pls check the paste height. Too much vol will cause short. For 15 mils use 5 mils thickness stencil if possible. Check profile preheat time to prevent hot slumpof the paste. 2) type 4 powder will be better for 15 mils pit
Electronics Forum | Thu Oct 02 08:26:41 EDT 2008 | rway
We had similar issues until we went to a 6 mil stencil thickness.
Electronics Forum | Tue Jan 08 09:23:18 EST 2013 | lock_2002
This is a question regarding soldermask between pins of fine pitch devices. The majority of our production designs end up with at least 2-3 mils of copper thickness on the external layers due to blind vias, wrap plating requirements, etc. Our curre
Electronics Forum | Tue Sep 30 14:06:04 EDT 2008 | realchunks
What pitch? You can go 5 mil or even 6 mil stencils depending on your screen printer. Also what do you consider "less solder"? What defect are you having. Remember on a QFP you use the heel filet to determine proper solder joint - not the toe.
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