Has anyone here seen an actual copy of [IPC-2221 or [IPC-2222? Do you think a hobbyist would see enough benefit from these documents to warrant purchasing either of them? I have viewed their respective tables of contents, and it seems like there might be some good reference material in both of these, but I would like to know what others think. Are there better resources for learning some of the nitty-gritty details and standard practices of PCB design?](IPC Store | IPC Store)](IPC Store | IPC Store)
If you are designing with the latest SMD parts and are getting your boards assembled professionally they would be useful. Most of the parts in the libraries supplied with the Pulsonix software I use conform to IPC. If that is the case with your software you might not need it, unless you are designing a lot of your own parts. If you are assembling your own boards manually proper solder fillets aren’t so necessary and you can easily adjust for any small errors in pad size, and so on.
Leon
I’m not paying for professional assembly at this point. I find that my software (gEDA) often lacks, or has incorrect, footprints that I need, but usually I can get specs from datasheets and draw my own. Someday I might try BGA in a toaster oven. So I’ll consider the answer as far as footprints are concerned to be “not yet.”
What about other parts of the specs? There seems to be a lot more there than just footprints. Do they just deal with tolerances that are beyond the concern of most hobbyists?
I think I’ve found that while the IPC documents can be generally handy for figuring out the rough sizes and pitches of things, nothing is a substitute for your part manufacterer’s datasheet with their specific tolerances, and, most importantly, having a physical part on your desk that you can print out a 1:1 footprint and compare the fit with.
A lot of places are helpful with samples and such, so if you plan ahead a week or two and order your samples, by the time you’re ready to start creating footprints you’ll have a bunch of samples you can compare with.
The PCB Matrix software is very useful for designing footprints that conform to the IPC standards. They have a free calculator.
Leon
I often come across datasheets that only have the drawings and specs of the pins but no recommended footprint.
I also had to make a pcb with a very fine BGA footprint and had to have it assembled by a professional. Only then I learned about fiducials when the assembler told me the machine required them. That was a pretty pricy and time consuming mistake. I’m thinking of getting the IPC manual just to make sure I don’t forget something like that again.
Is the document available online or do you have to order a printed copy?
@Leon: Thanks for the tip about the land pattern calculator.
@silic0or: I agree completely. I already make use of samples when appropriate.
@oliver_p: As far as I know, you have to purchase the IPC specs that I’m talking about. I don’t know if they are provided in an electronic format.