A liquid cooling jacket includes a base portion and a protruding portion protruding from an end surface on a first side in a third direction of the base portion in the third direction. A heat dissipation assembly includes a recessed portion recessed from an end surface on a second side in the third direction. A refrigerant flow path having a width in the second direction is between the end surface on the first side in the third direction of the base portion and the end surface on the second side in the third direction of the heat dissipation assembly. A position of the recessed portion coincides with a position of the protruding portion. An end portion of the protruding portion is farther on the second side in the first direction than an end portion on the first side in the first direction of the recessed portion.