pads spacing

Summary: Standard PCB manufacturing guidelines include minimum trace spacing of 4 mils, minimum pad aperture of 0.2 mm for mechanical drilling and 4 mils for laser drilling, minimum pad width of 0.2 mm, minimum pad-to-pad spacing of 0.2 mm, and copper clearance of at least 0.3 mm from board edges, with a recommended 20 mil inward shrinkage to prevent mechanical and electrical issues.