Electronics Forum | Fri Jun 11 08:38:55 EDT 2004 | davef
We figured you were going to say that. Pay me now, or pay me later, you call it. As an alternative: * Cover the backside of the via with masking tape that will take soldering temperature, like Kapon, or a temporary solder mask * Enlarge the apertur
Electronics Forum | Tue Oct 15 15:16:34 EDT 2002 | Abelardo Rodriguez Santana
We run into that issue all the time. If a corrective action must be done right away. Place Kapton tape on the bottom side of the board to cap off the via. If you have room to place tape if not use pink lady or something to plug the via. And weathe
Electronics Forum | Mon Aug 18 15:18:08 EDT 2008 | realchunks
Open the same size as the via's anular ring. Any slight off print will wet its way back into the via hole.
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 | Mon Aug 18 10:42:04 EDT 2008 | floydf
We are in the process of preparing for a new board that requires paste in hole processing. The hole is a .020" via, and our customer wants it filled with solder, but not bulging past flush. For printers,we use a DEK 249 with a squeegee, and a DEK 260
Electronics Forum | Mon Jan 10 19:13:46 EST 2000 | TNT
HELLO MIKE, THE PROBLEM WITH THE VIA BEING IN THE MIDDLE OF THE PAD CAN BE HANDLED. IF YOU ARE HAVING PROBLEMS WITH SOLDER FLOWING THROUGH AT REFLOW YOU MIGHT WANT TO CHECK YOUR VACUUM AT YOU SCREEN PRINTER. SOMETIMES THE VACUUM THAT HOLDS THE PCB
Electronics Forum | Wed Dec 08 11:26:04 EST 2010 | davef
3 Printer Area Conditions * As stated earlier, heat and humidity are damaging to solder paste. Ideally, the printing area should be maintained at 40% - 50% relative humidity and 72°- 80°F (22-26°C). In addition, no air (cool or warm) should blow dire
Electronics Forum | Tue May 12 04:15:48 EDT 1998 | Chris Sargent
Help! We have been doing some trials on Paste Through Hole and have encountered a problem. The screen is designed (as is suggested in technical info re PTH) to give double the paste volume required to fill the void between the pin and via. The pro
Electronics Forum | Fri May 15 18:18:51 EDT 1998 | Earl Moon
| Help! | We have been doing some trials on Paste Through Hole and have encountered a problem. The screen is designed (as is suggested in technical info re PTH) to give double the paste volume required to fill the void between the pin and via. The
Electronics Forum | Tue Mar 24 11:20:18 EST 1998 | Earl Moon
| Anyone have an idea how small a via must be to inhibit significant solder volume escaping into the via? Typically, micro vias are drilled and plated to about .003" diameter. To avoid significant solder "drain off," they should be drilled as shallow
