BACKGROUND

1. Technical Field

The present invention relates to a semiconductor module, and a vehicle.

2. Related Art

There are conventional, known semiconductor modules including a semiconductor element such as a power semiconductor chip (see Patent Literatures 1 to 5, for example).

Patent Literature 1: Japanese Patent Application Publication No. 2014-67902

Patent Literature 2: Japanese Patent Application Publication No. 2010-103222

Patent Literature 3: Japanese Patent Application Publication No. 2017-17195

Patent Literature 4: Japanese Patent Application Publication No. 2011-160519

Patent Literature 5: WO2016/204257

The total cooling efficiency was low since a capacitor generates heat if an input terminal of a semiconductor module is connected with the capacitor.

SUMMARY

In order to overcome drawbacks explained above, a first aspect of the present invention provides a semiconductor module including a semiconductor device, and a cooling device. The semiconductor device may have an input terminal. The semiconductor device may have a wiring portion that includes a first end portion, and a second end portion, and extends in one direction, the first end portion being connected to the input terminal. The semiconductor device may have a circuit substrate that includes a top surface, and a bottom surface, the top surface being provided with a first circuit board and a second circuit board along the one direction, the bottom surface being arranged on a top surface of the cooling device. The semiconductor device may have a metal body connected between the wiring portion, and a top surface of the first circuit board. The semiconductor device may have a semiconductor chip that includes a top surface electrode, and a bottom surface electrode, the top surface electrode being connected to the second end portion, the bottom surface electrode being connected to a top surface of the second circuit board.

The metal body may be connected to a portion of the wiring portion, the portion being closer to the input terminal than the semiconductor chip is.

The first circuit board may have an area larger than an area of contact with the metal body when seen in a plan view.

The input terminal may be an N terminal. The circuit substrate may further be provided with a third circuit board. The semiconductor device may have a P terminal. The semiconductor device may have a second wiring portion that includes a third end portion, and a fourth end portion, and extends in the one direction, the third end portion being connected to the P terminal. The semiconductor device may have a second metal body connected between the second wiring portion and a top surface of the third circuit board. The semiconductor device may have a second semiconductor chip that includes a top surface electrode, and a bottom surface electrode, the bottom surface electrode being connected to the top surface of the third circuit board.

The second circuit board, and the third circuit board may each have an L-shaped pattern including a longer portion and a shorter portion when seen in a plan view. The longer portions may each extend in the one direction. The longer portion of the second circuit board, and the shorter portion of the third circuit board may face each other, and be arranged with a gap therebetween, the gap extending in the one direction, and the shorter portion of the second circuit board, and the longer portion of the third circuit board may face each other, and be arranged with a gap therebetween, the gap extending in the one direction. The semiconductor chip, and the second semiconductor chip may be connected to the shorter portion of the second circuit board, and the shorter portion of the third circuit board, respectively, and overlap with each other only partially when seen in the one direction.

The second metal body may be positioned on the longer portion of the third circuit board, and be positioned closer to the P terminal than the second semiconductor chip is.

When seen in the plan view, the second circuit board may have an area larger than an area of contact with the semiconductor chip. The third circuit board may have an area larger than an area of contact with the second semiconductor chip and the second metal body.

The metal body and the second metal body may each be substantially a rectangular parallelepiped. A bottom surface area of the metal body may be smaller than a bottom surface area of the second metal body.

A longer side of a bottom surface of the metal body may be shorter than a longer side of a bottom surface of the second metal body. The longer side of the bottom surface of the metal body may be orthogonal to the one direction, and the longer side of the bottom surface of the second metal body may be parallel to the one direction.

The cooling device may have a top plate including a front surface, and a back surface. The cooling device may have a refrigerant circulation portion arranged on the back surface of the top plate. The cooling device may have a cooling fin provided to extend from the back surface toward the refrigerant circulation portion. The cooling device may have an inlet that is for letting in a refrigerant, and communicates with the refrigerant circulation portion. The cooling device may have an outlet that is for letting out a refrigerant, and communicates with the refrigerant circulation portion. When seen in a plan view, the metal body may be arranged at a position corresponding to a finned area where the cooling fin is provided.

The cooling device may have a top plate including a front surface, and a back surface. The cooling device may have a refrigerant circulation portion arranged on the back surface of the top plate. The cooling device may have a cooling fin provided to extend from the back surface toward the refrigerant circulation portion. The cooling device may have an inlet that is for letting in a refrigerant, and communicates with the refrigerant circulation portion. The cooling device may have an outlet that is for letting out a refrigerant, and communicates with the refrigerant circulation portion. When seen in a plan view, the metal body and the second metal body may be arranged at a position corresponding to a finned area where the cooling fin is provided.

When seen in the plan view, the circuit substrate may have a first end closer to the input terminal, and a second end opposite to the first end. When seen in the plan view, the finned area may have a first boundary closer to the input terminal, and a second boundary opposite to the first boundary. When seen in the plan view, a distance between the first end and the first boundary may be longer than a distance between the second end and the second boundary.

A second aspect of the present invention provides a vehicle including the semiconductor module according to the first aspect.

The summary clause does not necessarily describe all necessary features of the embodiments of the present invention. The present invention may also be a sub-combination of the features described above.

