Semiconductor device, power converter, method for manufacturing semiconductor device, and method for manufacturing power converter

A semiconductor device comprising:

• a metal plate;
• a semiconductor element disposed on an upper surface of the metal plate via a bonding material;
• and
• an external terminal bonded to the upper surface of the metal plate,
• wherein
• the upper surface of the metal plate and a lower surface of the external terminal are in contact with each other via a conductive material,
• in at least a part of a portion where the upper surface of the metal plate and the lower surface of the external terminal are in contact with each other, a melted portion of the metal plate, the external terminal, and the conductive material is formed, and
• the metal plate and the external terminal are each made of copper or copper alloy.

A method for manufacturing a semiconductor device, the method comprising the steps of:

• preparing an insulating substrate provided on at least its upper surface with a circuit surface;
• disposing a semiconductor element on an upper surface of the circuit surface via a bonding material;
• and
• disposing an external terminal on the upper surface of the circuit surface, and irradiating an upper surface of the external terminal with a fiber laser to bond a lower surface of the external terminal to the upper surface of the circuit surface, wherein
• the upper surface of the circuit surface is in contact with and bonded to a part of the lower surface of the external terminal,
• a melted portion of the circuit surface and the external terminal is formed in at least a part of a portion where the upper surface of the circuit surface and the lower surface of the external terminal are in contact with each other, and
• a gap between the upper surface of the circuit surface and the lower surface of the external terminal has a size of 20 μm or less.

A method for manufacturing a semiconductor device, the method comprising the steps of:

• preparing a metal plate;
• disposing a semiconductor element on an upper surface of the metal plate via a bonding material;
• and
• disposing an external terminal on the upper surface of the metal plate via a conductive material and irradiating an upper surface of the external terminal with a fiber laser to bond a lower surface of the external terminal to the upper surface of the metal plate via the conductive material, wherein
• the upper surface of the metal plate and the lower surface of the external terminal is in contact with each other via the conductive material;
• and
• a melted portion of the metal plate, the external terminal, and the conductive material is formed in at least a portion where the upper surface of the metal plate and the lower surface of the external terminal are in contact with each other.