Electronics Forum | Mon Sep 20 16:27:58 EDT 2004 | blnorman
Besides the processing tests (different print speeds, print delay times, etc.) one test we've had to use is humidity exposure. Solderballing due to high outside humidity is a problem in our plant. So we expose paste to 85% humidity for various time
Electronics Forum | Tue Nov 09 14:21:00 EST 2004 | Dreamsniper
Thanks Russ. When solder paste is applied, you can't see the pads. Because my aperture reduction is 5% - 10% of the pads. Pads are reduced by almost and up to 20% by the PWB Fab and the paste covers the pad. We cal align and inspect but very hard as
Electronics Forum | Fri Mar 04 10:04:14 EST 2005 | jbrower
We use Alpha UP-78 (Older paste formula) and it works well for what we do. We standardized our stencils at 5mil with a 10% reduction on IC apetures and a home plate design on passive components. Additionally we use laser cut electro-polished stenci
Electronics Forum | Thu Mar 17 13:03:21 EST 2005 | Slow Ride
When it comes to solder paste, you should worry about volume. Granted height is a part of the equation, but you could have perfect height and still get defects. I wouldn't get too wrapped up in volume either, unless you're evaluating stencil height
Electronics Forum | Mon May 16 06:36:51 EDT 2005 | steve
I see what you mean. Personally I would try a bit of the paste and see what you think prior to production run. If I were you I would get another brand in there. something that offers a "slightly" longer life? I have used "out of date" solder paste ma
Electronics Forum | Mon Jun 13 01:31:36 EDT 2005 | buchi79
Devef, The stand off height is 75micron. We only clean the product after underfill process. Dispense epoxy under the FC & cure it before aqueous wash. Samples are sent for LPC (liquid particle count) Test to ensure cleaniness. By the way, our plant
Electronics Forum | Fri Aug 26 22:12:27 EDT 2005 | iwan
Folks, I have been trying to get information about Malcom SP2 Solder Paste Softener spin speed from Internet and still waiting from supplier. Does anybody know about that one spin speed info? Also how to determine spin time to get a good paste base
Electronics Forum | Mon Oct 24 11:00:11 EDT 2005 | rlackey
You can't really use a pasted board to troubleshoot the program as any components not on target simply slide off with machine vibration and movement as they won't be held by the solder paste. Whereas on double sided sticky tape they remain in place
Electronics Forum | Tue Nov 01 09:21:39 EST 2005 | jdengler
I've never heard of this before. If your solder paste is at the correct temperature, and your process is under control you should have an acceptable print the first time. This sounds like a terrible waste on time and paste. Set up a DOE to prove tha
Electronics Forum | Fri Dec 16 06:46:12 EST 2005 | Rob
How about keeping a fridge near the line and only putting on the stencil what is needed, then topping up from the jar as & when? As soon as the paste hits the stencil flux will evapourate, and all of that time spent by people in labs developing comp
