Electronic control device

An electronic control device comprising:

• a housing that dissipates heat of a heat generation element;
• and
• a board that is in contact with the housing wherein the board includes
• a heat sink on which the heat generation element is mounted,
• a via that penetrates the board in a thickness direction, wherein the via is in thermal contact with the housing via an insulating heat transfer portion that is an insulator,
• a first layer formed on a first surface of the board that includes a first non-ground wiring that is in direct contact with the heat sink, and
• a second layer that is a layer closest to the first layer in the board, wherein the second layer includes a second ground wiring that is in electrical and thermal contact with the housing,
• a fourth layer formed on a second surface of the board, wherein the fourth layer includes a fourth ground wiring that is not in direct contact with the via but is in electrical and thermal contact with the housing and
• a third layer that is an inner layer closest to the fourth layer, wherein the third layer includes a third non-ground wiring that is in direct contact with the via;
• wherein:
• a potential of the housing is a ground,
• a potential of the heat sink is a non-ground,
• the first non-ground wiring and the second ground wiring overlap each other in plan view from the thickness direction of the board, and
• the third non-ground wiring and the fourth ground wiring overlap each other in the plan view from the thickness direction of the board.