Electronics Forum | Fri Jun 12 23:52:42 EDT 2015 | armandogomez
Reflow? or Wave solder? or selective wave solder? For what I understand you problems is with the preheaters you have a high temp that dries up the flux, and when hits the wave is doing that, do you have a thermal profiler? what's the temp just befor
Electronics Forum | Fri Jul 29 10:03:02 EDT 2011 | blnorman
At a previous location we used the Semco cartridges. Occasionally the operator would have to scrape down the stencil and knead the paste back in. That would keep the paste on the edges from drying out. It was just standard procedure.
Electronics Forum | Thu Dec 10 12:53:12 EST 2009 | deanm
Bryan, Dyoungquist is correct. You should not need to mix solder paste. Overmixing solder paste can adversely affect it. Follow these guidelines and you should be fine: 1. Keep unopened containers of paste in the refrigerator. 2. Take one container
Electronics Forum | Wed Feb 07 21:56:00 EST 2001 | davef
Every critter out there with large incisors adapted for gnawing and nibbling has a different theory of solder ball formation. [My theory: It�s punishment for using NC fluxes. Stand and deliver. My solder balls end-up in the gross filter connected
Electronics Forum | Wed Jul 27 09:58:05 EDT 2011 | davef
Pressure printing systems Conventional stencil printing techniques have fundamental limitations as regards paste handling: The volume of paste available for printing is limited, so frequent replenishment is necessary Paste is difficult to c
Electronics Forum | Wed Jan 30 15:10:09 EST 2013 | hegemon
Restoration of the fluxing properties? Can't see adding a liquid flux to a solder paste (assumed expired shelf life) in order to "restore" anything. If the volatiles in the original paste are gone, then adding more carriers and volatiles will not pr
Electronics Forum | Fri Dec 17 09:48:50 EST 2004 | grayman
I agree with dave. However, if you can not afford those expensive cartidges, you start putting enough solder paste on the stencil so to minimize waste. I agree you have to dispose of the excess dried up solder but if your process is not very critical
Electronics Forum | Thu Feb 07 05:24:16 EST 2008 | muarty
I would advise that you clean the stencil thoroughly at least every 4 hours, also though it is worth cleaning the stencil top and bottom after any breaktimes. To avoid solder paste drying off in stencil apertures. Best piece of kit I've purchased was
Electronics Forum | Tue Jun 13 12:03:10 EDT 2000 | Chris May
Jason, If 225C is the topside temp of your board just prior to hitting the wave, I would say this is too high. Your flux suppliers data sheet should tell you an ideal topside temp for good flux activation, probably around 190C. According to the Bi
Electronics Forum | Thu Dec 16 18:36:01 EST 2004 | mattkehoe
We use water soluble solder paste. When it gets a little dried out, can we add something to rejuvenate it? Liquid flux? We do not place components, just print and reflow the solderpaste so solderballs, spattering, and other issues like those are of
