Q:

Why do KiCad's library footprints for 0402 resistors and capacitors have different pad sizes?

KiCad's default library footprint for C_0402 is longer than R_0402.  Why?

A:

IPC-7351 specifies wider land patterns for chip capacitors than chip resistors, because capacitors are usually taller, so the solder fillet "wants" to extend further laterally.  Using the slimmer resistor footprint with a capacitor can lead to reduced assembly yield due to tombstoning.

