Screaming Circuits: QFN and DFN


Choose Your Package Wisely

As I mentioned in my prior blog, there are reasons to consider different packages than just physical size. Sometimes it is just space available on the PC board, but there may be other considerations as well. One of the first... Read more

QFN? QFP? QFwhat?

The QFN (quad flat pack, no leads) has become my favorite integrated circuit package. It's very compact, yet is easier to use than a micro BGA. Micro BGAs of 0.5mm and smaller pitch become a bit more difficult and costly... Read more

Super Small Via In Pad

Via in pad is an old issue that still pops up now and then. Our standard answer hasn't changed: No open vias in pads. But one of the questions we get related to the subject is: "What if we make... Read more

Creating a QFN Footprint - the center pad

I've written bits and pieces about creating footprints in Eagle and a lot about what the QFN solder paste layer should look like, so maybe it's time to connect the two dots. I'm using Eagle CAD here, so your process... Read more

More Beagle CAD Paws

Continuing on from my last post... As I said, I do everything I can to avoid re-using the package footprint when adding the the parts library in Eagle CAD. The schematic symbol can be a different story though. It still... Read more

Beagle CAD paw prints

Unfortunately, I can't generically hand out Eagle CAD QFN footprints without knowing the specific part, but I can illustrate the areas I initially had difficulty with. All of the traps that used to get me seem blindingly obvious now, but... Read more

More CAD footprint woes

AT this point, I really shouldn't call them "woes." More like business as usual. I'm talking about the need to make custom footprints, or at leas modify footprints. Back in the old days, the only thing needed to make footprints... Read more

"Shrinky Dink"

I had some "Shrinky Dinks" when I was a kid. Amazingly you can still buy them. You can also use that concept in your prototyping. I did that recently. I have a robot board design that I'd like to shrink... Read more


In the land of protorypes, sometimes "close enough" is good enough. That can save money on PC boards and assembly when a particular package version of your part is out of stock. But, it's not universal. Sometimes you can't go... Read more

QFN Stencil Gerber

In the previous epside, Wally’s attack on Dilbert’s kingdom prompts Ratbert to perfect an “N”-Ray, to be discharged from a powerful Nullitrion, to neutralize and render useless Wally’s power plant. Dilbert tells Dogbert the Nullitrion can best be directed against... Read more