Electronics Forum | Mon Jun 05 14:17:18 EDT 2000 | C.K.
Dream: Yes, VIA's are connected to actual SMD pads via traces - roughly .030" from the pad. The VIA is .013" in diameter, and the excess solder bleeds out of the actual VIA barrel after the 1st reflow.... -CK
Electronics Forum | Mon Jan 31 14:21:26 EST 2005 | Chunks
Not to put Heraeus down - but we experienced the same thing from time to time. We finally found out it was the humidity in building. The higher humidity would cause the bleed out of this adhesive. We switched to Loctite and the problem went away.
Electronics Forum | Fri Jun 02 09:31:26 EDT 2000 | C.K.
Okay, there's a debate here at my company. We build a card here that, often times, we get batches where there is excess HASL in the VIA hole barrels. Here is the problem that this causes: During the "1st reflow", the excess HASL bleeds out of the
Electronics Forum | Sun Jun 04 07:37:57 EDT 2000 | Dreamsniper
CK, just curious...is the via located close to a pad or land? if yes, what's the gap between the via pad and the component pad/land edge ? what's the Via hole size? Have you checked where does the solder that bleeds out of the via come from? Please
Electronics Forum | Mon Feb 12 15:57:25 EST 2007 | pr
Anybody out there using this with lead free paste and willing to share the good and bad? I used them a few years back and had some issues (wasted paste, paste bleeding out around the skids). Just curious if DEK has addressed those problems and how cu
Electronics Forum | Fri Nov 05 13:58:23 EDT 2010 | chartrain
I agree that the tines (webs between apertures) can become damaged on fine pitch stencils from a blast of air. If they get bent, the stencil won't seat and gasket properly allowing bleed out of paste. Of course we all know that the air being blasted
Electronics Forum | Fri Apr 08 15:27:05 EDT 2011 | stimpk
A couple more things to look at. ( DEK) Check you wiper blades. This is the rubber blade that holds the paper in contact with your stencil. When these wear down it will not clean properly. Also make sure when you run this product that you verify that
Electronics Forum | Tue Aug 22 12:14:21 EDT 2000 | Tekguy2000
There are concretions that form inside the chamber when using a water soluble paste. They start forming and affecting print as early as 2 days. This is apparent no matter what type of print head you may be using. There has been over 30 water soluble
Electronics Forum | Mon Jun 05 14:10:54 EDT 2000 | C.K.
Dave: Thanks for you Earl-Moonesqe explanations. To answer your 3 questions below: * If there�s no flux in the via, why does the sodder flow? I thought it was the flux that removed corrosion to increase wetting that allowed
Electronics Forum | Tue Jun 06 20:10:28 EDT 2000 | Dave F
You bet. It goes liquidous and tries to flow down hill flux or not. * And wudda wanna bet there�s still flux residues in those vias, anyhoo? Yes, you're right!! There might be excess flux residues in them via barrels....but why
