Screaming Circuits: CAD Parts Libraries

PROTOTYPE AND SMALL VOLUME
PCB ASSEMBLY MADE EASY

QFN Center Pad revisited

The QFN (quad flat pack, no leads) package can no longer be considered exotic. It was when I first wrote about it a decade ago, but not any more. In fact, with the wafer scale BGA, it's one of the... Read more

Never Take Pin Numbering For Granted

Our all-things-about-electronics manufacturing standards body, the IPC, specifies the proper numbering order for most components. That's a pretty nice thing that they do there, but it's not always enough to prevent layout mishaps. Case in point a line of small... Read more

Let's Talk About HAL - And Another Thing

A few days ago, I wrote about HASL PC board surfaces, explaining that it's not an appropriate choice for small parts. Look at the same PCB image as I used yesterday. You might not recognize it because yesterday, it was... Read more

How Much of that part number is important?

Part numbers are incredibly important, but can also be incredibly annoying and confusing. Obviously, we all need them, but it would be nice if there were some semblance of a standard. Well, there are some standards, like capacitor grades and... Read more

Accursed Diode Marking

Am I a broken record? Pretty much - especially when it comes to confusing diode marketing. For example, everyone knows what the diode symbol looks like, and pretty much everyone knows which side is the anode and which is the... Read more

Fiducials and Odd PC Boards

One of the handy aspects of getting boards assembled at Screaming Circuits is that we don't require fiducial marks for standard process boards. I would say that we build far more boards without fiducials than with. That's cool, but there... Read more

USB Type-C Connectors

It wasn't terribly long ago that pretty much every cell phone came out with its own custom charging cable. It was a major step forward when they all (except Apple) standardized on the USB micro-B connector. However, there are a... Read more

The Common Parts Library

The two most common causes of delay in small volume manufacturing here at Screaming Circuits (and presumably, others like us) are component availability, and footprint mismatches. We don't substitute parts without your approval for a number of reasons. I've written... Read more

Those Danged LEDs again.

I fell into one of my own favorite traps last week: the dreaded LED footprint mess. I designed a board based on the Microchip PIC32 - it's a ChipKIT Arduino-compatible board - that has a number of RGB LEDs. on... Read more

Indicating Polarity On Diodes

Everyone knows which way current flows through a diode. Right? Of course they do. Diodes only allow current to flow in one direction. Well, sort of. In the case of your garden variety rectifier, barrier diode, or LED, that's true.... Read more