Electronics Forum | Fri May 16 15:45:00 EDT 2003 | swagner
If the only difference between the two products is the board supplier I believe thats where I would start, we had a similar problem like this two months ago and it turned out to be a faulty (thin) HASL layer which did not meet our print tolerance. T
Electronics Forum | Fri May 30 04:20:59 EDT 2003 | Ben
Hi all I am facing the problem with reoworking CSP component for high frequency application boards. Our customer do not allow us to use tacky fluxes due to high frequency application and component has low standoff ,and the ball pad and ball size is
Electronics Forum | Thu Jul 17 09:26:28 EDT 2003 | Mike J
Mike: We have provided many carriers for flex circuit applications to facilitate processing through screen print, pick-and-place and reflow and, in many cases, eliminating the need for taping the flex circuit to the carrier. Please contact me and w
Electronics Forum | Tue Jul 22 09:05:14 EDT 2003 | davef
Any-Layer Interstitial [Inner] Via Hole (ALIVH). In printed circuit board fabrication, a registered mark of Matsushita Electric for a filled microvia structure in all layers for applications requiring small-size, lightweight build-up PWB to achieve
Electronics Forum | Thu Aug 21 09:34:57 EDT 2003 | davef
Woa. The more paste that you put a a BGA ball, the more likely that you'll bridge between balls. Why do you need to compensate for the size variance in BGA balls? How does using a 8 thou thick stencil to compensate for ball size variance? Fine pi
Electronics Forum | Thu Aug 21 15:10:59 EDT 2003 | paulm
Such balls (=/- 0.004)size variance can occur in a single part. If I have a ball in a part that could be (according to vendor specs) 0.008 larger than another ball the only way I can insure that the smaller ball makes contact with the paste is to hav
Electronics Forum | Thu Aug 21 16:58:25 EDT 2003 | justin
With a eutectic ball, you'll see about a 50% collapse. This negates that .008" issue you're referring to. With a high temp ball, you don't enjoy the same freedom regarding ball collapse. Dave is correct, though. We recently got IBM to sign up to
Electronics Forum | Fri Aug 22 10:20:26 EDT 2003 | Stephen
I hate being persnickity, I just am sometimes. You are not being told you "should expect" that variance. You are being told you can't sue them for manufacturing defects if the balls are within that range. That range is way bigger than what they wil
Electronics Forum | Fri Aug 22 15:49:40 EDT 2003 | paulm
Thanks Steve for your rather colorful and sarcastic input. If I correlate your asteroid assessment with what our QA Departments data(that tells us we are experiencing this problem about 5% of the time and I am guessing higher when we are forced or re
Electronics Forum | Tue Aug 26 14:13:46 EDT 2003 | robd
We have seen "coplanar problems" on BGAs supplied by some suppliers. We have seen large enough spere variation to cause opens with our standard .006" paste process (paste and profile work fine "most" of the time) . Although not an extremely technic
