Electronics Forum | Thu Oct 26 08:48:06 EDT 2000 | ptvianc
Of all of the process steps, paste printing is the most critical with respect to minimizing defects. Therefore, paste printing must be tightly controlled, particularly in the case of fine pitch (peripherally leaded) devices and BGAs. I believe that
Electronics Forum | Wed Jun 06 03:12:06 EDT 2001 | ianchan
Any blokes in process/QA, can recommend a solder volume, measurement machine, that has proven reliability, in its data readings, prefer that it comes, similar to "SMT m/c" camera-program-function, to remove operator-user variation. Appreciate any hel
Electronics Forum | Mon Jun 18 16:48:00 EDT 2001 | Gil Zweig
We have found a significant number of PBGA problems associated with physical deformation of the package. Deformations such as dishing (potatoe chipping) and delamination under the die (popcorning). These can be detected by x-ray by the variation patt
Electronics Forum | Tue Dec 22 10:59:20 EST 1998 | John Watt
Folk's, I'm in need of some help / direction. I'm working on my thesis for a masters based on looking at the effect's of the solder resist promoting / reducing the amount of solder ball's during wave. I'm looking at thing's like colour, texture, com
Electronics Forum | Thu Aug 13 12:27:21 EDT 1998 | Steve Arneson
I am looking for information on any Gage R&R studies for the CyberOptics LSM solder paste inspection system. If you are a current user of one of these systems, are you finding any problems with the repeatability due to operator variation? What issu
Electronics Forum | Sun Jan 19 10:25:54 EST 2003 | davef
You shouldn't freak. You want the pads on both sides of the BGA ball the same so that the torgue from changes in dimension due to different CTE [ie, interposer, solder, bare board, etc.] is balanced on the top and the bottom of the ball. So, the ma
Electronics Forum | Mon May 26 04:02:13 EDT 2003 | Franky
Dear sir, I think so with every idea , everyone is correct , paste , pattern of pad design ,profiling or solder mask on PCB ,and one of the cause of tombstone that I found is alignment of machine placing and solder printing , from my experience many
Electronics Forum | Thu Aug 21 15:50:12 EDT 2003 | davef
Couple of points are: * You're technically correct that ball height has the potential to vary by 8 thou, but we never see that much variation. Ball heights within a lot of components vary just about nil. * When we place BGA, we smush them into the p
Electronics Forum | Thu Dec 18 15:48:25 EST 2003 | Subhash Nariani
Hello, Does anyone have experience with the PCB assembly of 0.5mm pitch chip scale packages with HASL finish? Characterization data that you can share? Tribal knowledge has it that the height variations of the solder prevent the use of HASL for fin
Electronics Forum | Thu Dec 18 23:44:53 EST 2003 | Dean
...don't expect high yields with hasl on that device. Yeah, you an do it. But not reliably. Also, factor in board warp, bump tolerance AND HASL variation....recipe for disaster. can your process toleate a selective gold on the one device? How ab
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