Electronics Forum | Mon Apr 16 12:31:27 EDT 2001 | mparker
If, after all the good advice already given, the engineer insists on following his wacky design, you may still be able to influence some success. First you have the fab house plug the via holes with solder then you make sure that the bottom side of
Electronics Forum | Fri Nov 22 05:04:07 EST 2019 | SMTA-Matthew
We have some circuit boards where the solder mask seems clear instead of green on top of some of the tented via pads. No gold deposited during the ENiG process and no solder sticks to it but why is it clear and does it have any correlation to the thi
Electronics Forum | Wed Aug 24 21:57:45 EDT 2005 | adeline_ko
The blistering is around the plugging via. I can forward you the pic. For the plugging process, I'm not too sure how they plug. What is the correct practise for the plugging via. Now, what they did is. They will do a tenting process for both side.
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 Jul 15 16:12:23 EDT 2008 | boardhouse
Hi Armynski, I sell for an offshore board house, yes, it is common for offshore board shops to fill vias. The bubble is caused by air entrampment within the hole it self, when heat is applied during Hot air and the via is covered on both sides the e
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 | 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 | 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
Electronics Forum | Thu Jan 06 08:03:47 EST 2005 | davef
On solder in vias: It looks like the via are not solder masked well and pick-up solder either: * Solder coating ... OR * During leveling It's possible that the design specifies openings in the solder mask for these via. On solder in the unsupporte
Electronics Forum | Fri Jul 09 16:32:35 EDT 1999 | John
Thanks everyone. I appreciate the help. John | Q #1) Is it more reliable to have the mask tent over the vias or risk getting vias half filled with solder? These are vias with an .020" hole and .040" or .050" pad. | | Q #2) When speaking of annular
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