Electronic controlling apparatus

1. An electronic controlling apparatus comprising:

a circuit board in which conductor layers and insulating layers are disposed alternately;

a power circuit that comprises a plurality of power elements that are each mounted to a first surface of said circuit board so as to be connected to an upper portion wiring pattern that is formed by an upper portion outer conductor layer that is disposed on said first surface of said circuit board among said conductor layers; and

a control portion that is mounted to a second surface of said circuit board so as to be connected to a lower portion wiring pattern that is formed by a lower portion outer conductor layer that is disposed on said second surface of said circuit board among said conductor layers,

wherein:

said conductor layers lack a central plane in a thickness direction of said circuit board as a plane of symmetry;

a thickness of said upper portion outer conductor layer or of a first outermost position inner conductor layer that is positioned at a position that is nearest to said first surface inside said circuit board among said conductor layers has greatest thickness among said conductor layers; and

a thickness of one insulating layer among said insulating layers is thicker than thicknesses of insulating layers remaining among said insulating layers, where a thickness of each of said insulating layers is a thickness of a portion of an insulating layer between conductive layers that are adjacent to each other in a thickness direction of said circuit board.

2. The electronic controlling apparatus according to claim 1 , wherein said first outermost position inner conductor layer is connected to said upper portion outer conductor layer by a via.

3. The electronic controlling apparatus according to claim 2 , wherein a thermally conductive member fills said via.

4. The electronic controlling apparatus according to claim 1 , further comprising a first heatsink that is disposed near said first surface of said circuit board, and that contacts an upper surface of said plurality of power elements.

5. The electronic controlling apparatus according to claim 4 , wherein said first heatsink contacts said upper portion wiring pattern.

6. The electronic controlling apparatus according to claim 4 , wherein a heat-radiating member in gel form fills between said first heatsink and said upper portion wiring pattern.

7. The electronic controlling apparatus according to claim 1 , further comprising: a through-hole that connects said upper portion wiring pattern and a heat-radiating pattern that is formed by said lower portion outer conductor layer; and

a second heatsink that is disposed near said second surface of said circuit board, and that contacts said heat-radiating pattern.

8. The electronic controlling apparatus according to claim 1 , further comprising a second heatsink that is disposed near said second surface of said circuit board, and that contacts parts that constitute said control portion.

9. The electronic controlling apparatus according to claim 1 , wherein said plurality of power elements are disposed on said first surface of said circuit board so as to be distributed uniformly.

10. The electronic controlling apparatus according to claim 1 , wherein: said power circuit comprises a first power circuit and a second power circuit that are configured identically; and

said power elements that constitute said first power circuit and said power elements that constitute said second power circuit are divided on two opposite sides of a line segment that divides said first surface of said circuit board equally in two, and are disposed symmetrically so as to have said line segment as an axis of symmetry.

11. The electronic controlling apparatus according to claim 10 , wherein said control portion outputs controlling variable commands to said first power circuit and said second power circuit so as to be identical.