Electronics Forum | Tue Apr 26 03:28:26 EDT 2005 | Just mee
What test is applicable to check for QFN package with NiPdAu leadframe if leads/pad are solderable? what are the options other than dip and look solderability testing? Thanks,
Electronics Forum | Tue Apr 26 04:00:13 EDT 2005 | dj_jago
You could use a meniscograph to test for wetability. It will give you a tangible measure of the solderability of the component. Just do a net search for 'meniscograph'.
Electronics Forum | Tue May 03 09:30:50 EDT 2005 | BK
Go to Google Type Nanostar Select Logic Packaging-Nanostar In middle of page select SMT&2nd Level Relability of Nanostar You should find a 35 page PDF file that tells u everything. If not post your e-mail and I'll sent it to u
Electronics Forum | Tue May 03 15:15:33 EDT 2005 | dphilbrick
The biggest problem is getting paste on the board. We ran a board that had 8 per and would get an occasional insufficient solder joint. I would look into doing the boards with something like a SiPad process (www.sipad.net) My $0.02
Electronics Forum | Wed Apr 27 12:26:49 EDT 2005 | jdumont
Square you say? Wouldnt this give less paste deposition than a circle and basically reduce the standoff height the same as making the pad bigger? Would using a type 4 paste for this size stencil aperture (.013") be a good idea? Thanks JD
Electronics Forum | Wed Apr 27 13:50:01 EDT 2005 | russ
You will want the square in this case to be .013" with rounded corners (slight overprint). I do not see why you would need a type 4 paste for this. the aperture as it sits should release well but obviously there is something wrong.
Electronics Forum | Wed Apr 27 15:13:24 EDT 2005 | jdumont
If square apertures are supposedly better than round why arnt we using them for all BGA locations, even the larger ones?
Electronics Forum | Thu Apr 28 07:07:59 EDT 2005 | jdumont
Good point about the paste. We are using Kester 256 anyone have any experiences, good or bad, with this stuff? We have had pretty good luck thus far with it. Thanks JD
Electronics Forum | Fri Apr 29 07:09:10 EDT 2005 | jdumont
Really you think the 256 is the issue eh? I have some a sample of the type 4 powder size coming in hopefully today. Hopefully that will help, if not its back to the old solder eval drawing board. I love my job...
Electronics Forum | Sun May 01 00:42:02 EDT 2005 | KEN
What is your price difference between the #3 and the #4 powder. ....see where I'm taking this?
