Electronics Forum | Tue Mar 12 11:20:08 EST 2002 | BTaylor
I agree with davef on most subjects including this one , we have used a microscope and an experienced inspector for years and done just fine. Recently due to customer demands we an acquired an ASC 3-D inspection station, and it works great it told us
Electronics Forum | Wed Mar 20 11:55:19 EST 2002 | slthomas
Interesting. Ours failed miserably. Of course we toss everything on the stencil at the end of a shift (they are instructed to let it run down to minimal volume on the stencil as they approach quitting time) so it's not an issue. We are more concer
Electronics Forum | Wed Mar 20 00:55:01 EST 2002 | ianchan
Heyz...at this rate i'am losing my mind too! We have been doing the "looks good; look bad" approach, and backed it all up with Z-height paste measurements. Only thing there's this customer QA asking how we established those USL & LSL utilized in our
Electronics Forum | Wed Mar 20 19:53:11 EST 2002 | davef
Your customer's question is reasonable. Before you can establish your control limits, you need to take 25 to 30 data samples of 4 to 5 measurements. This says you need a 100 or more measurements before you can start charting. And even this much
Electronics Forum | Thu Apr 18 17:17:20 EDT 2002 | Eric Wolf
I have found a consistency in certain package types which hold a very close tolerance. We use a six mil laser with electropolish. BGA's are tight. Some IC's drift. I think the range and Cp is more important than the Cpk for today. The reason bei
Electronics Forum | Thu Aug 08 16:41:18 EDT 2002 | davef
On our last thing like that [5X5, 32, er 28?], we printed bumps on the QFN, but you can't do that, so there's no sense in tormenting you. Ideas that come to mind are: * Search around SMTnet for a paper by Chrys Shea on controlling dispense shots as
Electronics Forum | Fri Apr 19 08:01:40 EDT 2002 | jnunns
We have been doing BGAs for about 3 years in house. We started off with an outside contractor and then brought it in. We are doing a variety of sizes from .05 to .03 pitch. We have 2D capability at print, but do not use it on any but the .03 pitch. T
Electronics Forum | Fri Apr 12 15:43:25 EDT 2002 | Fuji Spares
Screening adhesive can be messy but is alot quicker than using a glue machine as long as you setupyour stencil machine either manual or machine, we also use steel stencils with a stainless squeegee but you can use a rubber squeegee not sure about pre
Electronics Forum | Thu May 09 10:00:19 EDT 2002 | brianockert
I'd tend to agree with what the others have said. Check the basics, board supports, setup, wiper paper working correctly. If it's a humidity issue, try taking some paste, place it on a chem wipe, and roll it around a bit, which removes some of the mo
Electronics Forum | Tue Apr 23 03:48:00 EDT 2002 | mitchell
The metioned process will work, but I do have 1 Question, How are the PTH comp. being inserted? If automated insertion is going to be used the process may have to change. Topside SMD - then Auto insert PTH, the reason for this, is depending on the p