Electronics Forum | Thu May 10 15:32:45 EDT 2012 | 14367
We are having a lot of tomb stoning with this no clean solder paste. It's limited to larger, complex boards, affecting 0603 ferrite beads, capacitors and SOT23s. It was suggested that paste removed from a stencil should not be put back in it's origin
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 | Thu May 10 22:16:51 EDT 2012 | davef
It's bad practice to remix used solder paste with new solder paste in the jar. Further, some would argue that it's bad practice to reuse solder paste period. If economics force you to reuse solder paste, store it for reuse in an empty jar. When rea
Electronics Forum | Fri May 11 10:59:39 EDT 2012 | 14367
Thank very much for the feedback. I was asked why mixing the paste was not a good idea. Could you provide the answer please? It's always better to hear from an outside expert:) The SOT23 - some of them have actually flipped upside down ; plus we hav
Electronics Forum | Sun May 13 02:08:26 EDT 2012 | isd_jwendell
In testing 63/37 SnPb NC paste I have seen HUGE differences in performance. Have you tried a different paste? I prefer AIM (NC257-2), they have performed well in each round of testing. My observations regarding mixing old and new paste: The paste ha
Electronics Forum | Fri May 11 09:56:58 EDT 2012 | cyber_wolf
Paste control is a subject that has a lot of unfounded claims surrounding it. What is the difference in having a "working paste jar" and a "new paste jar" Either way new and old are getting mixed at some point. We just don't buy onto the whole thing
Electronics Forum | Tue Nov 30 18:02:45 EST 2010 | flipit
62/36/2 is used often in thickfilm hybrid circuits where Pd/Ag conductors are used. The idea is that you saturate the joint with the 2% silver and thus help eliminate the leaching of the silver from the hybrid circuit pads or the component. We mix
Electronics Forum | Fri Jan 16 16:36:07 EST 2009 | boardhouse
i would not try to chemically clean the finish, you would just be asking for other problems. 1) I would ask your supplier their Hasl mix. Standard Lead hasl is 63/37 - it almost sounds like your boards have a higher content of Tin and your experien
Electronics Forum | Wed Sep 10 17:21:08 EDT 2008 | gregoryyork
Strange we use the 179~C eutectic 62/36/2 solder paste as standard in Europe. It is indeed 2% Ag in fact we dont sell 63/37 paste or very rarely. I think if you mix a little 60/40 powder with the 2% Ag alloy this overcomes the tombstoning problem.
Electronics Forum | Wed Oct 15 08:55:59 EDT 2003 | John
I'm looking at an application that would require 62/36/2 solder paste. We currently run 63/37. I'd like to change across the board to prevent a mix up, but I don't know what concerns/issues that might create. The PCB's we currently run are HASL fi
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