Electronics Forum | Mon Mar 04 17:52:59 EST 2002 | davef
Yes, providing the surface of the via is solderable. * If so, how much paste? => Vias come in various sizes. Boards vary in thickness. So, the amount of paste to fill a via varies. Roughly, you�ll need twice as much paste as the volume of the via
Electronics Forum | Wed Nov 21 15:02:46 EST 2007 | jlawson
From info I have been told from design standpoint, via in pads helps with managing EMC issues with working design, in particular for high speed digital/dense populated type PCB's. We had a manufacturing customer that had very low yield because of th
Electronics Forum | Mon Jul 26 18:01:30 EDT 1999 | Earl Moon
| Presently protos of micro-bgas (80i/o) pitch .030/.031 | 12BGA per assembly | | The board is a (.062, 4 layers) FR-4 using Dry film | Pads .014inch | Vias within footprint .020inch | Vias to be filled by bottom side(solder side) only .030in dia. F
Electronics Forum | Fri Jul 13 18:25:09 EDT 2007 | seankim10
It sounds like more has to do with plating. you may also check out the voiding issue especially if you have new FAB or the supplier. I had problems with a RF chip in QFN package due to insufficient grounding that voiding caused. This ground is often
Electronics Forum | Fri Feb 22 14:22:07 EST 2008 | stevek
Are you using nocleans, especially when you get to SMT? Years ago, I had OA wave flux get into vias that were plugged from the top under parts. It is really difficult to clean small, high aspect ratio vias. Cross sections showed that the copper in
Electronics Forum | Tue Nov 14 18:38:59 EST 2006 | Brandon
Hello all, I am having an issue with some boards on our Wave Solder. It is a Pb free wave and These particular boards are exibiting A LOT of what I call solder bubbles in the larger than usual vias and un-used thru holes. Settings: 4 inch/min 144c to
Electronics Forum | Wed Jul 07 13:41:42 EDT 1999 | Dave F
snip | | If you go for plugging be sure you have a protrusion spec that you can live with. This often results in little bumps of epoxy that can interfere with component placement. For us, tenting .015 vias usually gets us about 80% coverage from
Electronics Forum | Tue Feb 01 21:53:06 EST 2000 | Dave F
Emmanuel: You have choices to prevent the solder paste from flowing to the second side during reflow: 1 Have your board fabricator plug the vias. 2 Put a temporary solder mask on the secondary side vias. 3 Have your designer relay-out the vias unde
Electronics Forum | Fri Jun 11 03:50:39 EDT 2004 | Scott B
We currently have an issue with via's in pads which we have been living with for some time. The problem has now escalated with the need to increase the via hole size to achieve PCB fabricators aspect ratio's. We are now not only experiencing solder d
Electronics Forum | Tue Jul 27 11:32:01 EDT 1999 | M.L.
| | Presently protos of micro-bgas (80i/o) pitch .030/.031 | | 12BGA per assembly | | | | The board is a (.062, 4 layers) FR-4 using Dry film | | Pads .014inch | | Vias within footprint .020inch | | Vias to be filled by bottom side(solder side) only
