US Patent 7557302 Printed circuit board with electrostatic discharge damage prevention

A printed circuit board for preventing electrostatic discharge damage includes several electronic components thereon. The printed circuit board defines a number of through holes therein. The printed circuit board includes a signal layer. The signal layer defines a first copper foil and second copper foil thereon. The first copper foils are disposed around the corresponding through holes and connect with the through holes. The second copper foils are disposed around the first copper foils and extend to two adjacent edges of the printed circuit board. The first copper foil and the second copper foil have a number of saw teeth. A gap between the first copper foil and the second foil is in the range from 0.1-0.125 mm.