Electronics Forum | Thu May 24 08:55:25 EDT 2007 | ck_the_flip
Here's some quick things to look for: 1. Does your solder paste feel like concrete, does it roll-up into your squeegee blades, and stick to your stencil? If so, your problem is the solder paste. The mixture of powder and flux, or metal load is ou
Electronics Forum | Thu Nov 10 14:58:16 EST 2005 | Karkanov
Hi, I had a question from our ISO guy asking me how I know that the paste we use is in good condition? The problem is that he saw our operator put some old paste back in a empty jar to reuse it the next day. So his question is how do you know the
Electronics Forum | Fri Dec 01 12:02:15 EST 2000 | blnorman
I have over 10 years experience in aerospace materials, part of which was involved with vacuum casting inert propellant formulations. These propellants are in the range of 80 - 90% solids loaded with viscosities of 15 kP. I'm not sure where I could
Electronics Forum | Wed Apr 20 11:08:05 EDT 2005 | py
usual solder cream has a viscosity above 800 000pas at 25�C for each 1�C the viscosity change about 30 000 pas at 15�C you will have nothing ( 37% of viscosity less)on your board...
Electronics Forum | Wed Apr 27 22:36:47 EDT 2005 | devilhitam
is there any relation between solder paste viscosity and the length of time the solder paste being used in the machine? pls advice....
Electronics Forum | Tue Apr 19 09:09:28 EDT 2005 | russ
Here is one reason- It eliminates the viscosity change during printing operation from the paste warming up and getting thinner. I would contact your paste supplier and have them give you the full list.
Electronics Forum | Wed Apr 27 15:14:12 EDT 2005 | andymackie
The viscosity decrease on warming is one of the main reasons, but you also don't want to get moisture condensing on the surface of the paste. Activators in the paste (that are used to eliminate solderballs and enhance solderability on reflow) become
Electronics Forum | Thu Jul 20 13:01:07 EDT 2000 | qsheng
What is the difference of formulation No-Clean Sn63 with No-Clean lead free paste? Is there techniocal data in detail for performance property of No-Clean lead free paste (for example, viscosity, solderability, tack, print life, reflow profile)? Is
Electronics Forum | Thu Jun 06 15:55:28 EDT 2002 | arzu
I agree with the others and experienced the problem myself this week. Solderballs at the side of the chips. I looked at the board and found that the chip is pressing the paste away too much. This in combination with our quite big pads(and stencilaper
Electronics Forum | Fri Apr 20 16:05:17 EDT 2001 | gcs
We always reduce side to side, EXAMPLE: 12 mil width reduced to .010". Do you guys check viscosity ? Also maybe your guys are appling to much pressure on the sqweegee blades.
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