PCB newbie here. I'm using Autodesk Fusion 360 to design a PCB that is a modified version of the Arduino Nano IOT 33.
My questions are about selecting parts before sending to the PCB manufacturer:
For generic parts like SMD resistors, capacitors, etc., can I just specify a generic resistor (see screenshot) with the appropriate resistor value, or is it important to specify an actual part number from a real supplier/vendor (like going on to Digikey or Mouser, etc. and specifying that exact part and serial number)?
If it's necessary to specify exact parts, what if I pick a part that is in short supply with the manufacturer? Is there a way to pick parts that are likely to be in stock with the manufacturer already? I guess I'm not sure how it works- do PCB manufacturers order parts from suppliers, or do they typically have generic parts on hand already?
My goal is to minimize the cost and lead time for my boards, and I'm ordering in a pretty low minimum quantity as I'm still prototyping right now.
Best Answer
When I have boards built "outside" I issue a full BoM (bill of material) and, if the vendor cannot fit a particular part, they call me (or email me) to ask for a replacement part number. They usually have stock of other devices that will be good enough and, they will usually offer up these parts (and where they originally sourced them from) for my consideration.
As an added precaution, I always state what the techy details are on my BoM so typically a resistor will have stated: -
I also codify "generic" components on my circuit diagram and this code also finds its way into the BoM: -
Those component codes also get incorporated into component symbols (which some folk may find a little over-the-top): -
I always get boards built with full traceability back to source so that's something else that you might consider if quality is important (as it should be).
Your goal might be to do this but not at the expense of quality - keep hold of what parts are fitted if different to what you originally asked for. Any potential vendor that says something like "don't worry, we know what you want" would be struck-off any vendor list in my opinion.