Electronic circuit board and power conversion device

An electronic circuit board, comprising:

• a multi-layer printed circuit board having mounted thereon a magnetic part and semiconductor elements, the magnetic part being formed by a magnetic core and a coil pattern formed by a circuit pattern, and the semiconductor elements being connected to the circuit pattern;
• a cooler placed on an opposite side from a mounting surface of the multi-layer printed circuit board;
• an insulating member, which has heat conductance, and is placed between the multi-layer printed circuit board and the cooler;
• a plurality of screw fixing portions placed in surroundings of the coil pattern and the semiconductor elements to fix the multi-layer printed circuit board and the cooler together;
• and
• a heat radiation pattern placed between at least two out of the coil pattern and the semiconductor elements when viewed from a direction perpendicular to a principal surface of the multi-layer printed circuit board,
• wherein, when viewed from the direction perpendicular to the principal surface of the multi-layer printed circuit board, the semiconductor elements are each placed on a line segment that connects two screw fixing portions out of the plurality of screw fixing portions,
• wherein the heat radiation pattern, the screw fixing portion, and the cooler are directly connected in a manner that gives heat conductance and electrical conductance to the heat radiation pattern, the screw fixing portion, and the cooler.

An electronic circuit board, comprising:

• a multi-layer printed circuit board having mounted thereon a magnetic part and semiconductor elements, the magnetic part being formed by a magnetic core and a coil pattern formed by a circuit pattern, and the semiconductor elements being connected to the circuit pattern;
• a cooler placed on an opposite side from a mounting surface of the multi-layer printed circuit board;
• an insulating member, which has heat conductance, and is placed between the multi-layer printed circuit board and the cooler;
• a screw fixing portion placed in surroundings of the coil pattern and the semiconductor elements to fix the multi-layer printed circuit board and the cooler together;
• and
• a heat radiation pattern placed between at least two out of the coil pattern and the semiconductor elements when viewed from a direction perpendicular to a principal surface of the multi-layer printed circuit board, and disconnected to the coil pattern and the circuit pattern connected to the semiconductor elements,
• wherein the heat radiation pattern, the screw fixing portion, and the cooler are directly connected in a manner that gives heat conductance and electrical conductance to the heat radiation pattern, the screw fixing portion, and the cooler.