Electronics Forum | Mon Nov 05 02:51:48 EST 2007 | omidjuve
our boards have many smd pads that has vias under them so when the screen printer wants to print the solder paste on it , it will penetrate through the via to the bottom side of the board and cause many problem for us . i want to know that is it sta
Electronics Forum | Fri Nov 23 15:46:06 EST 2007 | mika
Question: We have an issue right know on a prototype batch with via in the pad on an very small pcb 50x50mm (in a panel of course). The designer has no room to move the vias as they said. The pcb is to packed with components also 8-layers. It is also
Electronics Forum | Mon Dec 07 14:55:41 EST 2015 | clydestrum
So I have an issue coming up that I'm not too sure how to handle. A board was designed with the wrong footprint for a 3-lead transistor in which the single-lead side has a much larger (think thermal pad for qfn) copper land than what is meant for the
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 | Sat Nov 24 15:44:28 EST 2007 | mika
Hi DaveF, I had a short look into the Nr1. IMPACT OF MICROVIA-IN-PAD DESIGN ON VOID FORMATION Most interesting reading, but one thing though, I could not find any information about the oven profile. Just a picture of it. My question is of about the
Electronics Forum | Tue Jun 02 21:27:22 EDT 2009 | davef
We've never heard of a situtation where oversized pads caused voiding. Your supplier is correct that the pads on the board should be the same size as the pads on the interposer, but this is to improve reliability issues. Search the fine SMTnet Archi
Electronics Forum | Tue Sep 25 14:08:59 EDT 2001 | davef
Oooo, the solder on the pad and PGA ball is flowing during reflow down the via to the secondary side? Why didn�t you say so?? ;-) Why would you expect that gravity and capillary action wouldn�t force solder to flow down the solder plated via to the
Electronics Forum | Thu Nov 15 08:25:08 EST 2007 | rgduval
I do think that the designer goofed, and used too large vias. I believe he only used on size via on the entire board, regardless of whether it was in a pad, or out on the board. I have seen vias in pad work, though. From a manufacturing standpoint
Electronics Forum | Fri Jan 14 12:59:07 EST 2005 | Dan Mendoza
I have used the rectangle shapes and round shapes with no noticible difference. The idea is to design the pads to accept the same solder volume per component. Components over two size pads will favor the higher solder volume side during reflow.
Electronics Forum | Fri Aug 23 12:33:37 EDT 2019 | ameenullakhan
Hi , Its CCGA part . with normal PCB pad opening similar to other BGA pad . Yes its very surprising and we are not able to analyze. What exactly went wrong. We have new stencil design for this now. Will run it tomorrow. Will update the results.
