Electronics Forum | Fri Aug 22 09:41:49 EDT 2003 | davef
Mantis: Kenny reflows paste on [wave solders] all via, not just the test via, to plug the via and provide for a pressure seal between the board and the test fixture. Beyond that, since solder is softer than copper [and fills the hole better], solde
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 | 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
Electronics Forum | Mon Jul 26 18:05:18 EDT 1999 | ScottM
| 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 Aug 22 09:44:45 EDT 2003 | davef
Kenny: Since you need to use water soluable flux and can't use no-clean, consider asking your board fabricator to plug the via.
Electronics Forum | Thu Jul 26 22:52:56 EDT 2007 | davef
Choices are: * Respin the board to move the via so that it is no longer under the pad. * Have the board fabricator plug and plate over the via. Search the fine SMTnet Archives for background.
Electronics Forum | Fri Jun 09 17:34:08 EDT 2000 | Melanie Mulcahy
I need some information regarding the acceptability/unacceptability of using tented vias with LPI soldermask. Long story on all involved, but basically I have a board that I have had manufactured with no problems which has BGA/uBGA parts, tented via
Electronics Forum | Mon Apr 22 15:05:47 EDT 2002 | tim_easterling
Depending on the volume of boards you are manufacturing, the most cost effective solution would be to epoxy plug the vias prior to LPI soldermask application. The technique is common practice and most suppliers can provide it will little or no cost a
Electronics Forum | Tue Aug 06 22:20:32 EDT 2002 | Computer
Hi , I am currently faced with a problem with the via hole on the component pad. The customer does not allow plugging of the hole and enlarging the stencil pad hole size or thicker stencil size may cause bridging to the component next to it.
