The pattern of pads that matches a specific chip package.glossary, Core concepts
The physical pad pattern on the PCB that matches a chip's package. Stored as .kicad_mod files in libraries like Package_DFN_QFN.pretty/. Lib references look like Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.6x2.6mm.glossary, Physical / electrical concepts
How it looks
Real geometry: CORE3588 copper, drawn from our board file (2D plan view)
The footprint of U10, a level-shifter chip on CORE3588, drawn from our board file with everything else hidden: just its pads (amber).
112 pads in a row, 0.65 mm apart...
2...and 12 more facing them: the footprint of this chip's package (TSSOP-24).
Real image: CORE3588, rendered by KiCad from our board file
The same spot rendered with the part on it.
1The chip itself, sitting on that footprint. Its legs land exactly on the pads.
How it works
Where it fits
Each package (QFN, SOIC, SOT-23, BGA) has its own footprint. The layout is a set of placed footprints joined by tracks.