Electronics Forum | Tue Nov 07 14:34:04 EST 2006 | jeffm
We are using Kester Type R520A, Alloy SN96.5/A63.0/CU.5 paste which is applied using an MPM Accuflex machine. Our plant Humidity is 38 degrees. We are seeing insufficient paste post stencil on fine pitch parts. Could this be an environment issue? In
Electronics Forum | Thu May 24 19:27:50 EDT 2007 | kevinjm
We have a similiar problem with kester em907, a pb free paste. You say that your AOI system picks up blocked apertures, do you mean that the printers own camera looks at the stencil and sees apertures blocked? Or, is it picking up insufficient paste
Electronics Forum | Fri Sep 25 16:38:56 EDT 2009 | esoderberg
empf issued an excellent study of calculated solder volume in the 90's. It used lotus 123 but is easily used in excel. I have used it for over 10 years. The only thing wrong is with leadless components. the amount of paste required generally is insuf
Electronics Forum | Fri Apr 04 01:39:21 EDT 2008 | slthomas
All of what Dave says is spot on. I suspect that the most likely corresponding defects on your assemblies would be poor wetting and insufficient solder.
Electronics Forum | Thu Apr 26 11:21:26 EDT 2007 | slthomas
Question...when the machine said something was wrong, was it reading something wrong (false failure), or was there a true descrepancy but not one that resulted in a bad connection (bridge or insufficient)? Also, did you perform a DOE on the process
Electronics Forum | Fri Mar 29 10:11:02 EDT 2019 | cyber_wolf
“For a number of years now, work has been proceeding in order to bring perfection to the crudely conceived idea of a transmission that would not only supply inverse reactive current for use in unilateral phase detractors, but would also be capable of
Electronics Forum | Thu Apr 29 17:35:17 EDT 2004 | Shinmoto
Hi there, We place FBGA packages on a lot of our memory modules. Our stencils have .013" square apertures and a .005" foil thickness. We are using a type 4 paste from Senju Comtek. The price difference is not that significant and readily available
Electronics Forum | Fri May 21 15:50:41 EDT 1999 | John Thorup
We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendors
Electronics Forum | Sun Mar 26 19:02:05 EST 2006 | ms
Hi We are running automatic stencil printers, open squeegees, stainless stencil, stainless blades, print speed 25-30mm/sec. We have a frustrating consistency issue printing .37x.3mm apertures on a 45pin LGA (11 pads each side, 1 large ground in mid
Electronics Forum | Wed Oct 25 12:38:05 EDT 2000 | Phil
Hi there!! You know what your QA is doing is right, coz by measuring the solder paste height can avoid the following defects: 1.Insufficient solder 2.Short solder or bridging 3.Solder balls SPC monitoring for paste height checking is required
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