A complete PCB package is composed of many different elements, and different components require different elements. Generally speaking, the package components include: sink hole size, dimensioning, chamfer size, pad, solder mask, aperture, hot air pad, anti-pad, pin number (Pin Number), pin spacing, Pin span, silk screen line, assembly line, no-wiring area, no-hole area, tag characters, assembly characters, 1-pin identification, installation identification, footprint, device height.
In Cadence allegro software, the following elements are required: pads (including solder mask, aperture, etc.), silk screen lines, assembly lines, tag characters, 1-pin identification, installation identification, footprint, maximum height of the device, Polarity mark (only for polar devices), origin. As shown, the package of QFN48 is shown.