Electronics Forum | Mon Apr 28 09:53:10 EDT 2003 | kmorris
I've got a set of apertures on a stencil that I would like to "plug" or block off. In the past we've done this with Kapton tape, but since this location is close to a fine pitch component, the thickness of the tape prevents good gasketing at the fin
Electronics Forum | Thu May 01 15:08:52 EDT 2003 | k_h
If Kapton tape doesn't work, I would recommend eating a few hundred bucks and ordering a new stencil. I think your asking for more trouble trying to plug the apertures with dried paste, glue, or anything else. It will dislodge sooner or later and pro
Electronics Forum | Mon Jul 29 15:24:07 EDT 2002 | OhioD
Interesting. From the reaction we got from DEK, I thought we were the only ones with pumpprint woes. We've tried 1 stencil with Bioact SC10, Hydrex SP&WS, Axarel, and Loctite remover on both Heraeus and Loctite glues. Some we spray, some we work-in m
Electronics Forum | Tue Aug 17 10:41:13 EDT 1999 | Steve A
Wayne, Sounds like a gasketing problem. When the horizontal apertures are bleeding but not the vertical apertures. Could be poor underside support, HASL miniscus issues, masking or plugging issues, but what many people do not account for is that t
Electronics Forum | Fri Feb 19 00:32:40 EST 1999 | ZEEK
| We are using .040" diameter fiducials (global and local) on our boards. They are solder covered and HASL. I get batches of boards where the p&p vision system has trouble reading the fiducial. The fiducial looks dark on the screen. The board ven
Electronics Forum | Sat Oct 12 06:43:49 EDT 2002 | davef
Alternatives to consider are: * Opening-up your stencil aperture put-down more paste to compensate for the amount that is being used to fill the via. * Relaying-out the board to plug and plate over the via. * Relaying-out the board to move the via fr
Electronics Forum | Mon Feb 26 20:02:42 EST 2001 | davef
First, I don�t understand why your board fabricator can�t do a good job plugging your vias. Additionally, when you consider that they forgot to plug the first batch of boards, it makes me wonder if they are desirable as a supplier. Generally, we us
Electronics Forum | Fri Apr 19 08:19:26 EDT 2002 | jnunns
If the solder balls are next to your discretes, you should consider a homeplate design on you stencil apertures. THe only other time we have seen soler balls is due to the raw card. If the vias are not plugged by the solder mask, solder and air can g
Electronics Forum | Mon Aug 18 13:37:23 EDT 2008 | realchunks
We do it all the time for air pressure reasons. Use a 6 mil stencil, print right on the via, aperture opening 100% same size as the via, on an 0.063" thick board. Doesn't leave a bulge and plugs the air. You can have your board house do this for y
Electronics Forum | Fri Jun 04 11:31:27 EDT 1999 | Tony
| I'm encountering a new problem at my new company that I haven't encountered before in my past life - and that's Wave Soldering VIA holes. | | We've been getting a rash of defects that we call in this company, "insufficient solder in VIA hole." The
