Semiconductor device
A semiconductor device 100 has a power transistor N 1 of vertical structure and a temperature detection element 10 a configured to detect abnormal heat generation by the power transistor N 1 . The power transistor N 1 includes a first electrode 208 formed on a first main surface side (front surface side) of a semiconductor substrate 200 , a second electrode 209 formed on a second main surface side (rear surface side) of the semiconductor substrate 200 , and pads 210 a - 210 f positioned unevenly on the first electrode 208 . The temperature detection element 10 a is formed at a location of the highest heat generation by the power transistor N 1 , the location (near the pad 210 b where it is easiest for current to be concentrated) being specified using the uneven positioning of the pads 210 a - 210 f.
1. A semiconductor device comprising:
a power transistor; and
a temperature sensing element configured to detect heat generation in the power transistor,
wherein
the power transistor includes:
a first electrode formed on a first-principle-face side of a semiconductor substrate; and
at least one pad located upon the first electrode in thickness direction of the semiconductor device so as to be connected to the first electrode electrically and arranged in a lopsided manner on the first electrode, and
the temperature sensing element is formed at a most heat-generating spot in the power transistor that is identified by lopsided arrangement of the pad.
2. The semiconductor device according to claim 1 , wherein
the at least one pad comprises a plurality of pads, and
the pads are arranged in a lopsided manner such that one pad on which current tends to concentrate most is uniquely identifiable.
3. The semiconductor device according to claim 1 , wherein
the at least one pad comprises one pad, and
the pad is arranged in a lopsided manner such that a current density distribution around the pad is lopsided in a particular direction.
4. The semiconductor device according to claim 1 , wherein
the second electrode is a substrate electrode for applying a supply voltage to the semiconductor substrate.
5. The semiconductor device according to claim 4 , further comprising:
a power line formed on the first-principle-face side of the semiconductor substrate; and
a via connecting between the substrate electrode and the power line.
6. The semiconductor device according to claim 1 , wherein
the power transistor is configured to function as a high-side switch of which the first electrode is connected to a load and of which the second electrode is connected to a power terminal.
7. The semiconductor device according to claim 1 , wherein
the power transistor is configured to function as a low-side switch of which the first electrode is connected to a ground terminal and of which the second electrode is connected to a load.
8. The semiconductor device according to claim 1 , wherein
the first electrode has formed therein a slit through which a conductor from the temperature sensing element is led up to an edge of the first electrode.
9. The semiconductor device according to claim 8 , wherein
the temperature sensing element is disposed in a vicinity of the at least one pad, and
the slit is formed to extend in a direction opposite to the at least one pad.
10. The semiconductor device according to claim 2 , wherein
the plurality of pads are arranged in a lopsided manner on the first electrode such that current concentrates most at a corner of a pad, among the plurality of pads, that is closest to a temperature protection circuit.
11. The semiconductor device according to claim 10 , wherein
the temperature sensing element is disposed in a vicinity of the corner.
12. The semiconductor device according to claim 10 , wherein
the temperature sensing element is arranged along, of a plurality of directions pointing from the corner to edges of the first electrode, a direction along which a distance from the corner to an edge is longer.
13. The semiconductor device according to claim 10 , wherein
the plurality of pads comprises a main pad and a sub pad, the sub pad being smaller than the main pad.
14. The semiconductor device according to claim 1 , further comprising:
a temperature protection circuit configured to forcibly turn OFF the power transistor when the temperature sensing element detects abnormal heat generation in the power transistor.
15. An electronic appliance comprising:
the semiconductor device according to claim 14 .
16. A vehicle comprising:
a battery; and
the electronic appliance according to claim 15 , the electronic appliance operating by being fed with a supply voltage from the battery.
17. The semiconductor device according to claim 1 , wherein
the temperature sensing element is disposed in a vicinity of one pad among the at least one pad and is arranged near the center of one side of the one pad.