Electronics Forum | Fri Nov 09 10:15:27 EST 2007 | devajj
Of course if you are an OEM you could go back to your design engineers and tell them via's in SMD pads is unacceptable. Put that in your DFM design guidelines. If you are an EMS provider you can also influence your customer by explaining the impa
Electronics Forum | Wed Nov 14 13:05:40 EST 2007 | rgduval
I had one project with micro-vias in 0805 and larger pads, with no issues. But my most recent project had vias that were larger than the 0402 pads that the via was in. To the point that for a number of the lands, there was no visible pads (a couple
Electronics Forum | Tue Sep 25 12:49:58 EDT 2001 | Hussman
Been there - done that. Makes a mess on that 2nd reflow process- doesn't it!?!?!? This is caused by design. If the open via is located in the land area, it will flow thru the via and cause pumps on the opposite side. You can have your vias filled
Electronics Forum | Tue Nov 13 08:11:16 EST 2007 | grantp
Hi, What is this unacceptable? Designed the PCB is much easer if this is possible, so it would be really good to know why via in pad is a problem in production. Grant
Electronics Forum | Fri May 06 08:47:05 EDT 2016 | davef
You're correct. This design will have a record amount of 0402 rework for tombstoning and misalignments. Suggest that the pads on each end of all components be the same size in order to balance wetting forces during reflow.
Electronics Forum | Mon Sep 24 18:00:58 EDT 2001 | jagman
Does anyone know the cause(s) of solder flowing through a via to the other side of board during reflow causing solder bumps on opposite side? Is this mainly a design issue or could it be process related? Any help is appreciated.
Electronics Forum | Mon Sep 24 20:49:59 EDT 2001 | jagman
I'm not seeing this during the wave solder process, rather the REFLOW (convection) process. The board was design with the vias located "in" the land area.
Electronics Forum | Mon May 09 09:23:45 EDT 2016 | markhoch
I agree with the previous two replies. This is a perfect design....if you're trying to create a graveyard full of tombstones.
Electronics Forum | Tue Nov 13 09:36:18 EST 2007 | rgduval
From a manufacturing standpoint, this isn't very nice. Vias will tend to wick solder away from the pad, resulting in insuficient solder joints, which require touch-up. The amount of times any solder joint is reheated should be minimized, as extra h
Electronics Forum | Tue Jan 04 07:22:12 EST 2000 | Michael Selva
One of the boards has a via designed right in the middle of a pad for a 1206 cap, one side only. This causes the solder paste to run into the via during reflow. We run No-Clean paste. One alternative is to increase the aperture on the stencil for tha
