Electronics Forum | Thu Sep 11 23:50:51 EDT 2003 | Dean
Epoxy is hydroscopic. A cavity will form when the cure furnace reaches the boiling point of water. The steam expansion creates the pocket. It can be large enough to be filled with molten solder from the wave machine and cause a hard short under th
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 | Fri Nov 23 16:32:05 EST 2007 | davef
There a several things you can do to prevent the solder wicking down the hole with the current design, and that's where you should focus. Cost goes up as you go down the list, but in neither case do you need to respin the board, have solder starvatio
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 Oct 12 12:12:13 EDT 2018 | davidsmullins
We have some fairly standard 0.1" pitch, two row, shrouded, through hole headers soldered onto a thick backplane. There are tiny inspection holes along the bottom edge of the plastic body that allow an inspector to observe the top of the through hole
Electronics Forum | Mon Oct 15 14:36:03 EDT 2018 | davef
The methods of verifying PTH hole-fill. 1 Visual inspection 2 x-ray inspection works very well for inspecting such a connector for voiding and hole fill. View the connector off-vertical, at between 30 and 45 degrees. As always, the solder connect
Electronics Forum | Wed Oct 17 12:05:08 EDT 2018 | charliedci
We had a selective solder installation tech raise the connector body off of the PCB slightly with a spacer to allow for a visual inspection to verify the process/profile. A few years back we invested in a large enclosure X-ray with a manipulator arm
Electronics Forum | Fri Oct 12 16:04:10 EDT 2018 | davidsmullins
75%?
Electronics Forum | Fri Oct 12 16:01:23 EDT 2018 | davef
Feature||Class 1||Class 2||Class 3 Circular wetting of solder of the lead and plated hole barrel on the component side.||Not Specified||180 deg||270 deg Plated hole fill.||Not Specified||75%||75% Circular fillet and wetting of solder of the lead a
Electronics Forum | Sat Oct 13 09:26:35 EDT 2018 | davef
So, why do you think that the requirements for accepting a solder connections would change depending on whether the connection is or is NOT visible?
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