Electronics Forum | Wed Jul 07 10:25:13 EDT 1999 | John Thorup
| | 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. | | John, | It depends......mainly on the via size. Tenting works on smaller vi
Electronics Forum | Tue Feb 03 13:39:08 EST 2009 | grics
Good morning Jamie. I work at a CM and can offer some input on process flexability. I do not have any data on how reliable the coating is but I can say that they are both very difficult to control. Will you be selective coating or full coating? Ho
Electronics Forum | Thu Oct 01 08:34:50 EDT 2009 | davef
First, the reflow thermal recipe provided by your paste supplier is only a ball park guess. Beyond that, the temperature measured by thermocouples on your oven heaters are only loosely related the temperature of solder paste on your board. You need t
Electronics Forum | Tue Jul 27 16:44:31 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(sol
Electronics Forum | Tue Jul 27 17:23:45 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 b
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 Apr 19 08:19:26 EDT 2002 | jnunns
If the solder balls are next to your discretes, you should consider a homeplate design on you stencil apertures. THe only other time we have seen soler balls is due to the raw card. If the vias are not plugged by the solder mask, solder and air can g
Electronics Forum | Mon Nov 11 11:28:32 EST 2002 | davef
Sand is not a great conductor, compared to copper. Never heard of using the stuff on RF boards. Our board fabricator uses Dupont CP100, now CP101, [or something like that cuse who's going to check?] when plugging via on cheap boards. Your board fa
Electronics Forum | Mon Aug 18 13:37:23 EDT 2008 | realchunks
We do it all the time for air pressure reasons. Use a 6 mil stencil, print right on the via, aperture opening 100% same size as the via, on an 0.063" thick board. Doesn't leave a bulge and plugs the air. You can have your board house do this for y
Electronics Forum | Thu Apr 11 00:54:49 EDT 2019 | SMTA-Vikram
Yes, we have try different Flux, probes. etc... also not to paste vs Paste Via, but still we have ~3% NDF due to contact issue. I am looking for selective pasting with less flux dispenser.Any idea or anyone has used? What about plug via before pas
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