I understand that components can report that their package is the same as some standard, but that's not always true and there is some deviation. Most datasheets have a recommended footprint pattern. When the PCB fab house reviews a footprint, it is the recommended footprint from the datasheet that is used as the correct footprint. So deviating from the recommended footprint causes delays in rechecking, confirming and acknowledging they don't match the datasheet, as well as potentially not even working at all, depending on how wrong the footprints are.
For the component BLM15PD121SN1D, I see the following dimensions which don’t match the datasheet. Why is that?
Added 2 years, 5 months ago.
Thanks so much for this feedback. We followed the IPC industry standards to generate this footprint. We typically use IPC-7351B for surface mount components, such as this one. You can see that here: https://imgur.com/a/gPOnmeB
If they are not standard IC or chip packages (ex: connectors) we use the recommended footprints like you mentioned. The reason we use IPC as a general rule is that it provides a standard we can apply across all manufacturers consistently
By the way, Mike, it's a great idea that you allude to to have *both* the IPC version and the datasheet recommended footprint. Actually, this is why we show the different parts in the dropdown, so we can show variants of that same PN.
I will communicate this idea to our team to see what we can do to get there faster. It's definitely something we'd love to have in the long run. That way we can satisfy both options!
What IPC-7351B document are you following? I just googled, and the first hit from the standard in 2009 revision brought up naming conventions. I see:
Ferrite Beads should use "FB_Mfr.’s Part Number"
There are no hits for prefixes starting with "BEAD".
Answered 2 years, 5 months ago.