Semiconductor module, semiconductor device, and vehicle

A semiconductor module, comprising:

• a circuit board having a plurality of conductive patterns;
• a base on which the circuit board is mounted;
• a case that covers the circuit board mounted on the base, the case having a sidewall surrounding an outer periphery of the circuit board and a lid positioned above the circuit board;
• a plurality of conductive plates each of which is electrically connected to a respective one of the plurality of conductive patterns of the circuit board and extends to an outside of the case through a corresponding slit provided in the case, the plurality of conductive plates each being parallel to a predetermined plane;
• and
• a sealing material that seals the circuit board, wherein
• the lid of the case has a partition that protrudes in a direction parallel to the predetermined plane from an inner surface of the lid toward the base, and is disposed in an area of the inner surface of the lid above the circuit board, between two of the plurality of conductive plates to insulate the two of the plurality of conductive plates from each other, and
• the partition has a first portion and a second portion, in a side view of the semiconductor module that is viewed in a direction perpendicular to the predetermined plane, the first portion being located at a position at which the partition and the plurality of conductive plates overlap each other, the second portion the being located at a position at which the partition and the plurality of conductive plates do not overlap each other, and
• the second portion of the partition has a cutout section that is disposed such that in a depth direction perpendicular to a surface of the base, a distance from the surface of the base to an end of the second portion is greater than a distance from the surface of the base to an end of the first portion.