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 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 | Sat Dec 02 10:23:47 EST 2017 | tomh
Have you ever heard of "Solder Mask Defined Thermal Pads"? I wrote a short blurb on this here - https://www.pcblibraries.com/forum/ipc7093a-btc-qfn-solder-mask-defined-thermal-pad_topic2154.html This technology saves fabrication costs by not havi
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
Electronics Forum | Thu Oct 01 11:40:17 EDT 1998 | Justin Medernach
Are there anyone who can give me the answer about solder ball problem? | We have 12 layer PCB and double sided PCB. After one side reflow soldering We found lots of solder ball under the PCB. The solder ball was coming out from via hole. | So
Electronics Forum | Tue Sep 22 09:07:02 EDT 1998 | Steve Gregory
Hi Jacqueline! Do these joints that you're having problems with happen to be on fine pitch solder joints? Are the fillets staying attached to the foot and separating from the pads cleanly? If that is true, are there many vias concentrated aroun
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 | Sat Aug 21 02:16:42 EDT 2010 | isd_jwendell
I do not have a QSP-2, but build boards where others have done the layout. Some have not included fiducials, and I am left finding other things. Some boards have complete tenting over the vias, so not all PTH pads will work. Drill holes are not as ac
Electronics Forum | Fri Nov 22 16:19:45 EST 2019 | davef
I'd guess ... + Pads have no solder mask, clear or otherwise. + Pads won't take solder, because you're trying to solder to nickel. + Nickel on the pads is oxidized and is sticking out its tongue at the flux you're using. + Something went south
Electronics Forum | Thu Dec 15 11:06:05 EST 2005 | Samir Nagaheenanajar
You might wanna try a small reduction in your stencil aperture. For example, for a 30-mil pad go 26-mil square aperture with 8 to 10-mil radius on your corners. Also, look at your designs. Is there enough resist between your pad and ball? Another
