niconiconi20h ago
One of the most annoying things in #electronics: you can run a trace under a 0603 resistor, but you can't do that under a 0603 capacitor. The IPC footprints are slightly different, taking the height of the capacitor body into account.
Show threadGraham Sutherland / Polynomial19h ago

@niconiconi this is one of the reasons I don't include footprints with my auto-generated Altium & KiCad libraries for JLC's parts.

however, I *am* working on a thing that lets you turn their EasyEDA footprints into Altium/KiCad footprints, to get around this annoyance.

Show threadniconiconi18h ago
@gsuberland "to get around this annoyance." But it's incorrect to get around this annoyance, IPC says no because capacitors are not resistors with a different aspect ratio, mixed footprints degrade yield during reflow, perhaps by creating more tombstones. I also don't understand what does JLC have anything to do with it. This is the industry standard.
Show threadGraham Sutherland / Polynomial18h ago

@niconiconi no no, I don't mean the standard is annoying!

I have a tool that generates parameterised parts for Altium and KiCad from the JLC parts DB. people often asked why I don't include a footprints library to go with it, and this is one of the reasons - I don't have the height data to generate correct IPC footprints for the parts, so I don't. it's an annoyance in the sense that it'd be nice if I could include footprints.

Show threadniconiconi
@gsuberland Interesting. But how useful would that be? What are examples of parts that are both useful and parameterizable? Most ICs follow JEDEC and use IPC footprints, so no need to auto-gen those. Most connectors have strange vendor-specific footprints, and you can't auto-gen those, and most two-terminal devices are also in standard packages. The only non-standard 2-terminal parts that I remember that I used are gas tubes and transient suppressors, with footprints taken from the datasheets, none of which is particularly autogen-able.
Jun 15 at 3:07pmWeb
Show threadGraham Sutherland / Polynomial17h ago

@niconiconi the parameters are stuff like resistance, power rating, voltage rating, etc. so you can search them easily in your libraries.

the footprint is a convenience thing. drag drop a part into your schematic, and the footprint is already assigned.

the way I do it right now is I just give each component entry a generic footprint name ref, so as long as you have a footprint called "R0402" or whatever it'll use that. but you're responsible for making that to your needs.

Show threadGraham Sutherland / Polynomial17h ago
@niconiconi but I explain it a bunch in the readme. there's stuff like density class to consider, for example. makes it a big pain if you wanted to have a convenient drag-drop solution for all passives (which is generally why people seek my libraries!) - there are quite a few variables on 2-pin passive footprints even with just the IPC standards.