Electronics Forum | Tue Apr 26 18:23:30 EDT 2005 | russ
How does your machine recognize the part? Does it use vision for ball inspection or a just a body scan? What is the aperture size on the stencil? Have you calculated the area ratio? What is the aperture shape? What type of paste are you using? is
Electronics Forum | Thu Sep 29 19:18:24 EDT 2005 | HLy
Hi, I noticed that the solder joints on my BGAs end up with a lot of wrinkles after reflow. See picture at: http://pstr-r02.ygpweb.aol.com/data/pictures/02/01A/17/DD/E3/9E/n8BhepQLFDs6GMSwaRNxPCTWR5NdpUJZ0300.jpg Does anybody have any ideas what cau
Electronics Forum | Tue Jun 02 21:27:22 EDT 2009 | davef
We've never heard of a situtation where oversized pads caused voiding. Your supplier is correct that the pads on the board should be the same size as the pads on the interposer, but this is to improve reliability issues. Search the fine SMTnet Archi
Electronics Forum | Wed Oct 20 11:32:23 EDT 2004 | pbatten
Has anyone seen a footprint for these new parts? If so where? Thanks http://america.renesas.com/media/products/common_info/package/mitsubishi/j48fhh.pdf
Electronics Forum | Wed Oct 20 11:32:28 EDT 2004 | pbatten
Has anyone seen a footprint for these new parts? If so where? Thanks pbatten http://america.renesas.com/media/products/common_info/package/mitsubishi/j48fhh.pdf
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 | 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?
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