Electronics Forum | Mon Mar 05 16:16:08 EST 2007 | Mark
Hello, We are having issue with one of the customer board. This is 10 layer PCB FR4 with black solder mask. Coating Ni/Au. Soldering leadfree. We are using 7 zones air reflow oven (zones top&bottom). We have bed solder flowing for this boards. T
Electronics Forum | Wed Dec 06 07:24:22 EST 2006 | davef
Successful solder paste overprint is a function of the solder paste rheology, solder mask and through hole component stand off. * Solder mask with a high surface energy will permit a larger overprint than a solder mask with a lower surface energy. In
Electronics Forum | Tue Dec 05 03:39:39 EST 2006 | pavel_murtishev
Good afternoon, Due to problems with power connector soldering I have to overprint paste on pads for this connector. Stencil thickness is 125um and I cannot make it thicker. Area ratio of chip resistor assemblies limits stencil thickness to 125um. R
Electronics Forum | Wed Dec 06 06:09:02 EST 2006 | Loco
Would say about the same as above, 8mm according to a cookson presentation we had, of course it would depend a bit on the paste you are using.
Electronics Forum | Wed Dec 06 16:17:31 EST 2006 | Mario Scalzo, CSMTPE
Normally, we try to limit the over print of the paste to the width of the pad on both sides. If you are using 500um pad, then I wouldn't try over a 1500um aperture. Mario Scalzo, CSMTPE, Dartmouth 6 Sigma Green Belt Technical Support Engineer - Ind
Electronics Forum | Wed Dec 06 08:29:50 EST 2006 | David
Hi Pavel, We regularly use over printing on a multitude of problem parts including fine pitch QFP's. In an Automotive Environment the only thing you can change without a mountain of paperwork is the stencil. best way to work out how much you can get
Electronics Forum | Fri Oct 29 13:45:03 EDT 1999 | David Vulcano
We are placing several axial components that have STEEL leads. Have noticed that the steel components do not get good flow thru(we manufacture to IPC-A-610 Class II Standards which reqires 75% flow thru) We are using Seho Wave Machines with Nitroge
Electronics Forum | Thu Nov 16 23:34:56 EST 2006 | mds33200
Hi, I am new in this industry and have purchased a beguinner unut, a 3-in-1 solder, desolder, hot air station. Currently I work on cellphone mainboards. At the moment I only replace single large chips on the mainboard. I would like to be able to repl
Electronics Forum | Fri Nov 17 15:12:26 EST 2006 | mds33200
Hi, I am located in Auburn Mass (USA) right near Worcester. Now I noticed you talked about micro stencil for a populated PCB, would I need one? Or could I use a syringe to lay a tiny dot of paste since im only replacing a chip or 2 (at the moment)? I
Electronics Forum | Fri Nov 17 16:24:18 EST 2006 | billwestiet
I'm in North Attleboro, small world. To answer your question, you can deposit small dots of paste with a syringe. Kind of tricky work, and there are small stencil soluions out there fairly inexpensively. See http://www.minimicrostencil.com/ (I do
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