Screaming Circuits: CAD Parts Libraries

PROTOTYPE AND SMALL VOLUME
PCB ASSEMBLY MADE EASY

VLV - Very Large Vias

I recently received a question over on Twitter. Tomaž Šolc, AKA avian2 asked: "@pcbassembly What is your opinion on the "one big plated drill in QFN ground pad" pattern? pic.twitter.com/M9ZLftpuo0" I answered back: "Bad for machine assembly, okay for hand... Read more

Pads on Ground Plane

Generally, small pads for passive parts are connected with a single PCB trace of equal size to each pad. That's the right way to do it. However, sometimes, circumstances dictate a little different approach. The illustration on the upper right... 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

CAD Data Files

I've spent a fair amount of time researching and writing about the centroid file and about CAD library footprints. One of the challenges in this industry is that somethings that are "standard" really aren't all that standard. That's why we... Read more

Push-me Pull-you LEDs

I may never get tired of talking about LED and diode polarities. It's so much fun. Not long ago, I wrote about two LEDs from the same manufacturer, marked with opposite polarities. I recently ran into another one, but at... Read more

LEDs - Seeing Double

Like I do so often, I'm being a bit redundant. While I'm all for stamping out and eliminating redundancy, this is redundancy with a purpose (not a porpoise). Not long ago, in a galaxy not far away, I blogged about... 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 cautionary tails

I recently wrote about the horrors of LED marking variations. Unfortunately, LEDs aren't the only place to find inconsistencies in our world. Another part to keep a close eye on is the ubiquitous three-terminal voltage regulator. For just short of... Read more

How NOT to mark a diode

A while back, I wrote about ambiguity in the markings on electrolytic capacitors. In doing that, I cobbled together a little image to illustrate how surface mount electrolytics are marked. Take a look at the image below: Note how I... 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