Electronics Forum | Wed May 22 13:51:20 EDT 2002 | Phil
2 suggestions - Get a good scope - at least a 4X, but more like a 6X, 10X is best. You have a choice on used equipment for a substantial savings. A Leica Stereo 4 zoom is it. You can look for BGA scopes that have a 90` angle for looking at the balls
Electronics Forum | Wed May 29 10:11:50 EDT 2002 | wilcoxito
Thanks for your input, Alex. I appreciate it. I'd still like some input on diamond-shaped apertures if anyone has had experience with them.
Electronics Forum | Wed May 29 10:52:56 EDT 2002 | slthomas
Just wondering why you'd use a diamond shaped aperture? Seems like it'll just fill in the corners and be pretty much round anyway, so why not just start out that way and keep the volume you want?
Electronics Forum | Wed May 29 13:16:33 EDT 2002 | jax
The only reason I can see for doing this is: Apply more paste than a one-to-one round can provide. Square, diamond, etc... does not matter. Normally this is done for PTP applications but,... If it gets the job done, who cares.
Electronics Forum | Wed May 29 19:04:39 EDT 2002 | russ
I have heard of using diamond apertures for BGAs to tell you in XRay inspection if you reflowed (diamond means that paste did not reflow) that is the inly thing I coud think of as to why you qould want to do this. Russ
Electronics Forum | Fri Jun 07 15:16:25 EDT 2002 | gdstanton
Ben, Get a copy of IPC 7525 and review it. This will help you understand the relationship of aperture geometry to paste transfer. Good Luck, Greg
Electronics Forum | Tue Jun 25 16:15:20 EDT 2002 | dason_c
Hussman, I know when the oven temp at around 140F and the relative humidity is below 10% and meet the J-STD requirement but I never see any recommendation from the supplier to store @ this temperature. Can U advise where I can get more information?
Electronics Forum | Mon Jun 03 11:51:44 EDT 2002 | Troy
A 50KV machine will allow you to see solder bridges and balls under the BGA. It will also allow you to check placement and can "see" through the metal housing. If you want to inspect for voids, then you what to look at equipment in the 100KV range.
Electronics Forum | Wed Jun 05 21:33:12 EDT 2002 | davef
Tough to say based on what you have told us. Things to Determine are: * Is the heat at the solder connections that are not reflowing properly adequate? * Is the pad surface of the solder connections that are not reflowing properly solderable?
Electronics Forum | Thu Jun 13 20:55:46 EDT 2002 | russ
Having just gine through a similar problem myself (with much less equip.) Here are a few things to consider and/or look at Do you have the proper pad size? It should be the same size as the pad on the BGA. Is the board warping during your operati
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