Solid-state relay

The utility model relates to a solid-state relay, which comprises a shell, a circuit board, a metal oxide semiconductor (MOS) tube, a heat dissipation block and a heat conduction column are arranged in the shell, the MOS tube is arranged on the front face of the circuit board, the heat dissipation block and the heat conduction column are arranged on the back face of the circuit board, and the end portion of the heat conduction column is inserted in the heat dissipation block. A positioning hole is formed in the circuit board, a heat-conducting gasket is welded in the positioning hole through reflow soldering, the heat-conducting gasket is in contact with the MOS tube, the MOS tube is welded on the circuit board through reflow soldering, and the heat-conducting column is welded on the heat-conducting gasket through reflow soldering. By adopting the technical scheme, the utility model provides the solid-state relay, the heat-conducting gasket is welded on the back surface of the circuit board by utilizing reflo