Patent ID: 8853559

Claim:
An insulation circuit board comprising: a metal base substrate; an insulation layer; a first wiring pattern which is formed onto at least one surface of the metal base substrate through the insulation layer; a second wiring pattern which is formed onto at least one surface of the metal base substrate through the insulation layer, and a third wiring pattern which is in contact with the insulation layer, at least a portion of the third wiring pattern located between the first wiring pattern and the second wiring pattern where the distance between the first wiring pattern and second wiring pattern is closest, and the third wiring pattern configured not to be coupled to an electric ground potential and configured to divide a voltage between the first wiring pattern and the second wiring pattern, wherein an electric potential difference exists between the first wiring pattern and the second wiring pattern, and wherein the third wiring pattern has an electric potential in a range of the electric potential difference between the first wiring pattern and the second wiring pattern.