Semiconductor device, and alternator and power conversion device which use same

A semiconductor device comprising:

• a first external electrode to be attached to an alternator, the first external electrode having an outer peripheral section, which has a circular shape in top plan view;
• a MOSFET chip;
• a second external electrode disposed on one side of the MOSFET chip, on the other side of which the first external electrode is disposed;
• a control circuitry to which a voltage at a drain electrode of the MOSFET chip and a voltage at a source electrode of the MOSFET chip are inputted or a current flowing between the drain electrode of the MOSFET chip and the source electrode of the MOSFET chip is inputted, the control circuitry generating a control signal provided to a gate of the MOSFET chip on the basis of the voltages or the current;
• and
• a capacitor that supplies electric power to the control circuitry,
• wherein the second external electrode has a pedestal having an extent within the circular outer peripheral section of the first external electrode,
• wherein the MOSFET chip and the control circuitry are mounted on the pedestal of the second external electrode,
• wherein the second external electrode, the drain electrode of the MOSFET chip, the source electrode of the MOSFET chip, and the first external electrode are disposed so as to be stacked in this order in an upward direction,
• wherein the drain electrode of the MOSFET chip and the second external electrode are electrically connected with each other,
• wherein the source electrode of the MOSFET chip and the first external electrode are electrically connected with each other, and
• wherein the capacitor is mounted on the pedestal of the second external electrode via an isolation substrate.

An alternator comprising a rectification circuit, the rectification circuit comprising:

• a high-side circuit in which a first semiconductor device is incorporated as a rectification device;
• and
• a low-side circuit in which a second semiconductor device is incorporated as a rectification device,
• wherein both of the first semiconductor device and the second semiconductor device comprise:
• a first external electrode to be attached to an alternator, the first external electrode having an outer peripheral section, which has a circular shape in top plan view;
• a MOSFET chip;
• a second external electrode disposed on one side of the MOSFET chip, on the other side of which the first external electrode is disposed;
• a control circuitry to which a voltage at a drain electrode of the MOSFET chip and a voltage at a source electrode of the MOSFET chip are inputted or a current flowing between the drain electrode of the MOSFET chip and the source electrode of the MOSFET chip is inputted, the control circuitry generating a control signal provided to a gate of the MOSFET chip on the basis of the voltages or the current;
• and
• a capacitor that supplies electric power to the control circuitry,
• wherein the MOSFET chip of the first semiconductor device and the control circuitry of the first semiconductor device are mounted on the first external electrode of the first semiconductor device,
• wherein the first external electrode of the first semiconductor device, the drain electrode of the MOSFET chip of the first semiconductor device, the source electrode of the MOSFET chip of the first semiconductor device, and the second external electrode of the first semiconductor device are disposed so as to be stacked in this order in an upward direction,
• wherein the drain electrode of the MOSFET chip of the first semiconductor device and the first external electrode of the first semiconductor device are electrically connected with each other,
• wherein the source electrode of the MOSFET chip of the first semiconductor device and the second external electrode of the first semiconductor device are electrically connected with each other,
• wherein the capacitor of the first semiconductor device is mounted on the first external electrode of the first semiconductor device via a first isolation substrate,
• wherein the second external electrode of the second semiconductor device has a pedestal having an extent within the circular outer peripheral section of the first external electrode of the second semiconductor device,
• wherein the MOSFET chip of the second semiconductor device and the control circuitry of the second semiconductor device are mounted on the pedestal of the second external electrode of the second semiconductor device,
• wherein the second external electrode of the second semiconductor device, the drain electrode of the MOSFET chip of the second semiconductor device, the source electrode of the MOSFET chip of the second semiconductor device, and the first external electrode of the second semiconductor device are disposed so as to be stacked in this order in an upward direction,
• wherein the drain electrode of the MOSFET chip of the second semiconductor device and the second external electrode of the second semiconductor device are electrically connected with each other,
• wherein the source electrode of the MOSFET chip of the second semiconductor device and the first external electrode of the second semiconductor device are electrically connected with each other, and
• wherein the capacitor of the second semiconductor device is mounted on the pedestal of the second external electrode of the second semiconductor device via a second isolation substrate.