Electronics Forum | Thu Sep 02 15:51:15 EDT 2004 | cburress
All: IPC does not directly state any criteria for physical characteristics of what a filled via should look like when embedded within a surface mount component's pad. I am using several of these in my design, and have received PCBs that exhibi
Electronics Forum | Thu Sep 16 10:11:58 EDT 2004 | cburress
davef, Thanks for the reply. I've talked with IPC and they are currently reviewing this and attempting to compose some criteria. They "informally" recommend no greater than .002" also.
Electronics Forum | Thu Sep 02 22:23:44 EDT 2004 | davef
Dunno about something formal. After you specify your hole size and fill material, why not say something like: " Surface to be planar prior to final plating and metallization. Boards must be suitable for via in pad technology." We do not allow plati
Electronics Forum | Thu Mar 24 16:06:34 EDT 2011 | nkinar
Thanks for the reply, davef. Due to prototyping time constraints, I've been asked by the engineers if I could do something on the SMT line to salvage this prototype PCB. Could I do anything to connect the pad or fill the via? Much of the board h
Electronics Forum | Wed Jul 07 09:47:41 EDT 1999 | Peter Brant
| | 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. WIth regards to this question, and scott's follow up, I have used the "epoxy me
Electronics Forum | Thu Mar 24 15:58:52 EDT 2011 | davef
Just build-up the boards and ship them. Be sure to inform your customer about the problem that you have with their design and ask that the via be filled and plated over to prevent the problem in the production runs.
Electronics Forum | Tue Jul 06 19:38:01 EDT 1999 | 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 rings, I have always thought of them as minimums. Su
Electronics Forum | Tue Aug 03 14:46:25 EDT 2004 | russ
We recommend to the designers "the smallest diameter that you can get away with", that will help reduce the solder scavenging into via diring reflow. unless you are planning on having them filled as Dave F mentioned. Russ
Electronics Forum | Fri Aug 16 10:00:03 EDT 2002 | davef
You have a very bad situation. It�s tough for the gas, flux material, er whatever to escape when the BGA is sitting on top of it and the blind via is blocking it from the other side. Obviously the vias should have been: * Placed on the edge of the
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
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