Screaming Circuits: Via in Pad


More Thoughts on Via Near Pad

The other day, I wrote about vias near pads. The post got a couple of interesting comments on the Circuit's Assembly blog, where it was also published. Some very interesting thoughts there. One of the things Mich said was: "When... Read more

Via Near Pad

Vias don't go well in pads, of course. In fact, I think it's fair to say that vias go as well in pads as large igneous rocks go in peanut butter and jelly sandwiches. But it's not just vias in... Read more

What's Wrong With This Picture?

What's wrong with this picture? I forgot to warn you that there'd be a pop-quiz. It's only worth 10% of your final grade though, so not to worry. We're fully into the rainy season here in Oregon now. It's dumping... Read more

Parts Substitution Gone Big

I've mentioned some cautions with parts substitutions before; wrong V values on barrier or flyback diodes, counterfeit parts and things like that. Here's another example of something to watch out for if your supply is tight and choices are limited.... Read more

Via in Pad with Passive Components

Most of the via-in-pad writing I do concerns BGAs and QFNs. I do cover other parts from time to time, but the subject seems to come up most often with those packages. It is an important subject with passives too... Read more

Tented QFN/QFP Via in pad

Here's a pretty decent example of mask-tented vias in the thermal pad of a QFP. Most manufacturers recommend no more then 100 - 125 um wider than the via to minimize voiding and thermal insulation in cases like this. This... Read more

Via-In-Pad - Let It Slide???

No. Sometimes, you can get by with vias in your pads. Sometimes, but not very often. I wrote about this a while back here. The thing is, I was talking about big pads - like QFN or QFP thermal pads... Read more

Getting on My Via-In-Pad Soapbox Again

There's never enough time. There's never enough money. There's never enough room. I certainly say those things often enough, and sometimes it's actually true. But other times, I'm just not looking in the right places. Here's a board that is... Read more

Layout 101 in 1989

I just noticed a twitter tweet about my most recent via-in-pad post: "I could understand this if it was 1989, but egads, thats layout 101 @pcbassembly A Few More Via In Pad No-no's", from mnphysicist. I tend to agree... Read more

A Few More Via In Pad No-no's

This first footprint will result in a minimal connection at best on the pad on the left. The via takes up nearly the whole thing so the pad barely has any metal and the open via will suck the solder... Read more