PCB bonding pad size design method, PCB bonding pad and PCB

The invention belongs to the field of PCB design, and provides a PCB bonding pad size design method, a PCB bonding pad and a PCB, and the method comprises the steps: obtaining the solid pin width and pin tinning length of a to-be-packaged device; the width of a target bonding pad is determined according to the fact that the two sides of a solid pin of the to-be-packaged device are evenly expanded outwards by a certain threshold size; determining the length of a target bonding pad according to the extension of different sizes in the inner and outer directions of the entity pin of the to-be-packaged device; and repositioning the center of the target bonding pad based on the deviation between the center line of the length direction of the target bonding pad and the center line of the entity pin. By limiting the width of the target bonding pad and positioning the pins through the bonding pad, the welding defect caused by insufficient or excessive soldering tin of a device in PCB welding is effectively prevented,