Electronics Forum | Tue Nov 13 09:32:28 EST 2007 | kpm135
For the simple fact that the via in the middle of the pad causes the solder to wick into the hole instead of flowing out across the pad and part. Thus cause insufficient solder issues.
Electronics Forum | Tue Nov 13 09:36:18 EST 2007 | rgduval
From a manufacturing standpoint, this isn't very nice. Vias will tend to wick solder away from the pad, resulting in insuficient solder joints, which require touch-up. The amount of times any solder joint is reheated should be minimized, as extra h
Electronics Forum | Fri Apr 12 17:22:47 EDT 2002 | davef
First, splitting hairs on parlance. * Conformal Coating. A thin electrically nonconductive protective coating that conforms to the configuration of the covered assembly to provide environmental and mechanical protection. * Solder Mask. Coating mate
Electronics Forum | Fri Jun 07 09:50:13 EDT 2019 | teejsd
Closer pics at angle would seem to support soldermask delam. And I am now wondering if our no clean flux is getting properly inactivated where it is sitting under the mask.
Electronics Forum | Fri Jun 07 11:10:08 EDT 2019 | teejsd
We also have a Foresite C3 for spot testing for ionic contamination. I didn't use it at this spot, but used it some other spots around the PCB that showed this color change and with our C3 we were passing IPC standard for ionics. But I was wonderin
Electronics Forum | Mon Feb 06 10:02:14 EST 2006 | Yash Sutariya
Sorry. I actually should clarify those slides. Black pad is not associated with tented vias. Also, you can tent vias with soldermask, but this requires the immersion gold process to be completed prior to soldermask. As such, all copper features (
Electronics Forum | Wed Sep 15 22:52:58 EDT 2004 | pdeuel
We had same problem. Solder balls appeared on top side of board and led to damaged second side stencles. We worked around problem by running blank boards thru oven and inspecting and removing solder before processing boards with parts.
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 | Thu Sep 01 11:25:21 EDT 2005 | chunks
Unless it is peppered with via holes. Then it depends on the size of the pad and via holes.
Electronics Forum | Wed Aug 09 16:30:43 EDT 2000 | MarkS
Has anyone had (successful) experience placing testpoint vias under BGAs? We already have conventional vias, but we're contemplating converting them into testpoints (probably by enlarging the bottom-side copper diameter to .036" and opening the bott
