Low capacitance over-voltage protection part

Disclosed is a low-capacitance overvoltage-protection semiconductor device for a lightning protection system, in particular to a low-capacitance overvoltage-protection semiconductor device with required capacitance less than 30 pF used in high-frequency field. The low-capacitance overvoltage-protection semiconductor device is mainly composed of a emission junction, an electricity-collected junction, a pin and a lead frame; a chip combines a dual-end four-layer bidirectional symmetry structure through three P-N junctions; each group is doped into four layers, N2,P2,N1 and P1; an A aluminum layer is arranged at the external side of the emission junctions; an A copper pin is arranged at the external side of the A aluminum layer; a short-circuit hole is arranged between an N zone and a P zone; the pin of the semiconductor protecting chip is connected with the lead frame through a metal lead wire. The low-capacitance overvoltage-protection semiconductor device has the advantages that the device has the dual-end fo