I write a fair amount about component footprints/land patterns/CAD library components — whatever you call them. What are you supposed to call them anyway? I’ve heard them called all three of those things and a few other names as well. Seems like a good case for some terminology standardization. Or maybe I just need to do some more research on that specific subject.
I’m curious as to how common it is that a designer needs to create a custom footprint for a part. I seem to have to create at least one for every project I do and I rarely use new parts or complex packages. Of course, I don’t use CAD packages that cost gobs of money, either. Just Sunstone’s PCB123 and Cadsoft Eagle. PCB123 has all of the NXP parts so that’s good, but it’s not just the big components that get you.
In a board I ‘m just finishing up – 22 BOM line items, I had to make a custom library part for a crystal and modify a library part for my microcontroller. I had to create some custom footprints for a couple of connectors too, but half way through the layout, I upgraded Eagle and discovered that someone else had just done the same thing I needed for the same connector, and uploaded it to the Eagle site, so I used their work. Hopefully I haven’t made any of the mistakes I always write about.
I really am curious as to how many designs typically require at least one custom footprint and how many custom footprints per design would be a typical rule of thumb.