Electronics Forum | Mon Sep 25 10:18:00 EDT 2000 | Vic Lau
Dear Friends, I am handling a new project, and search for a solder paste stencil printer (automatic or semi-automatic) for lead free solder paste. The one I had looked for is MPM3000 series, however, what I heard from other freinds, those model is
Electronics Forum | Thu Jan 20 14:28:49 EST 2000 | Scott S. Snider
I ran this test back in '92 or '93 when Alpha was first pushing to change from Brookfield to Malcolm readings. The correlation between Malcolm readings to solder paste height is good. I could always look at the viscosity reading and know at least a d
Electronics Forum | Fri Feb 21 19:41:25 EST 2003 | neil
I have had a look at what Bob Willis say's and the answer to my problem is not there. The paste we are using has a very high viscosity and I beleive that if we reduce the metal content to less than 90% it will solve the problem. The problem is parti
Electronics Forum | Wed Feb 14 10:10:55 EST 2007 | rob_thomas
The challenge regarding the stencil was mostly due to the actual board layout and nothing having to do with the voids in the solder. It was my first encounter with 0.5 mm pitch on BGA and dealing with a LF solder paste with higher viscosity than tha
Electronics Forum | Sat May 12 08:58:23 EDT 2012 | davef
On mixing paste: There could be a lot of hand wringing about the need to minimize solvent evaporation, flux separation, and chemical activity. [True alarmists will throw in oxidation of the alloy.] But I think the real concern is a change in viscosit
Electronics Forum | Wed Nov 02 11:01:56 EDT 2022 | tommy_magyar
Ellaborating on Evtimov's answer: - solder paste type, think about solder granulation and viscosity. Both of these will directly affect print quality if wrong print parameters used. You will normally find recommended print parameters on the solder pa
Electronics Forum | Wed Feb 25 21:37:12 EST 2015 | dinhhuunam
Hi Bartel , 1.1 Profile Solution to Cold Soldering Cause for Cold soldering The peak temp of reflow is too low. The preheating temp is too high and it takes too long Solution Lower the preheating temp and increase the peak temp in the reflow zone
Electronics Forum | Wed Mar 14 09:07:34 EST 2001 | blnorman
We just ran a study to try to determine this. We exposed the paste to 85% humidity to simulate worst case manufacturing. At various times we removed the paste from the chamber and tested it for tack, solder balling, wetting (copper coupon), and vis
Electronics Forum | Mon Oct 20 11:48:34 EDT 2003 | blnorman
Who said there was NO evaluation? The paste we chose was evaluated based on a 20 point test score as well as material compatibility. Once we introduced it to manufacturing each line had problems. For one manufacturing treated it as a drop in repla
Electronics Forum | Tue Feb 12 18:48:48 EST 2008 | larryd
Thanks for the spare change. Questions are good and I did miss one item. Process has 100% solder paste inspection with a 3D inspection machine that has very few false calls or accepts. Ramp to peak is less than 1.5C/sec. Profile looks good, solder
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