DE-112024002485-T5 - Power conversion device

Abstract

A power conversion device comprises: a semiconductor packing containing a semiconductor element; a printed circuit board containing a wiring layer connected to the semiconductor packing and having a pair of surfaces facing each other; a first heat dissipation element which is brought into contact with a heat dissipation surface of the semiconductor packing via a first thermal conductivity element; and a second heat dissipation element which is brought into contact with a surface formed on the same side as the heat dissipation surface of the semiconductor packing under the pair of surfaces of the printed circuit board via a second thermal conductivity element, wherein the first heat dissipation element and the second heat dissipation element are mounted in a state in which they are displaceable relative to each other, and the first thermal conductivity element and the second thermal conductivity element are arranged to partially overlap each other.

Inventors

• CHEN TI
• ARAKI TAKAHIRO
• TOKUYAMA TAKESHI
• KANNO KIYOTAKA
• KUSUKAWA JUNPEI

Assignees

• ASTEMO LTD
• HITACHI LTD

Dates

Publication Date

20260507

Application Date

20241018

Priority Date

20231020

Claims (10)

1. Power conversion device comprising: a semiconductor packing containing a semiconductor element; a printed circuit board containing a wiring layer connected to the semiconductor packing and having a pair of surfaces facing each other; a first heat dissipation element contacting a heat dissipation surface of the semiconductor packing via a first thermal conductivity element; and a second heat dissipation element contacting a surface formed on the same side as the heat dissipation surface of the semiconductor packing beneath the pair of surfaces of the printed circuit board via a second thermal conductivity element, wherein the first heat dissipation element and the second heat dissipation element are mounted in a state in which they are displaceable relative to each other, and the first thermal conductivity element and the second thermal conductivity element are arranged to partially overlap each other.
2. Power conversion device according to Claim 1 , wherein the first heat dissipation element and the second heat dissipation element are arranged such that sections of them overlap and the sections are in contact with each other via a deformable element.
3. Power conversion device according to Claim 1 , wherein a section of the second heat dissipation element, which is in contact with the circuit board via the second thermal conducting element, protrudes more towards the circuit board than the first heat dissipation element.
4. Power conversion device according to Claim 2 , wherein the second heat dissipation element partially overlaps the first heat dissipation element at a position that is closer to the circuit board than the first heat dissipation element.
5. Power conversion device according to Claim 1 , wherein the circuit board has a through hole formed at a position that is in contact with the second heat conducting element via the second heat dissipation element.
6. Power conversion device according to Claim 5 , wherein the circuit board is attached to the second heat dissipation element via the second heat conducting element by means of a fastening element located adjacent to the through-hole.
7. Power conversion device according to Claim 1 , comprising: a capacitor connected to the printed circuit board, the printed circuit board having the wiring layer at a position adjacent to a connection point with the capacitor.
8. Power conversion device according to Claim 1 , wherein the first heat dissipation element is formed by laminating a first layer made of a thermal interface material (TIM), a second layer made of an insulator, and a third layer made of a TIM.
9. Power conversion device according to Claim 8 , wherein the first heat dissipation element is arranged such that the first layer is in contact with the heat dissipation surface of the semiconductor packing and the third layer is in contact with the first heat conducting element, and an area of the first layer is smaller than an area of the third layer.
10. Power conversion device according to Claim 1 , wherein the first heat dissipation element is formed by laminating a first layer made of a thermal interface material (TIM) and a second layer made of an insulator.

Description

Technical field The present invention relates to a power conversion device. State of the art A power conversion device that alternately converts direct current (DC) and alternating current (AC) power through the switching process of a semiconductor element exhibits a high conversion efficiency and is therefore widely used in consumer applications, in-vehicle applications, railway applications, substations, and the like. In this power conversion device, the semiconductor element generates heat during the switching process, and a printed circuit board (PCB) on which the semiconductor element and various components are mounted, and which incorporates a wiring layer, also generates heat when a large current flows through the wiring layer. Therefore, it is necessary to cool both the semiconductor element and the PCB, and a cooling structure capable of achieving this is required. For example, a cooling structure described in PTL 1 was proposed as a cooling structure capable of cooling both the semiconductor element and the printed circuit board. PTL 1 describes a cooling structure for a power conversion device comprising a printed circuit board on which a plurality of circuit bodies, each containing a semiconductor element, are mounted. The AC and DC wiring connecting the plurality of circuit bodies on the printed circuit board are in contact with heat dissipation projections formed in a cooling water channel via an insulating film. Citation list Patent literature PTL 1: JP 2023-7184 A Summary of the invention Technical problem In the cooling structure described in PTL 1, a section that contacts the circuit body within the cooling water channel and a section of the heat dissipation protrusion that contacts the printed circuit board (PCB) containing the AC and DC wiring are integrally formed as a single cooling water channel. To achieve high heat dissipation performance by bringing the cooling water channel, circuit body, and PCB into close contact, while ensuring the necessary insulation distance between the cooling water channel, circuit body, and PCB, it is necessary to precisely match the shape of the cooling water channel to the distance between the circuit body surface and the PCB surface. However, during the manufacturing process, variations occur in the shape of the cooling water channel and the distance between the circuit body surface and the printed circuit board surface, depending on their respective tolerances. Therefore, precise alignment is difficult, and a certain degree of error is introduced. Depending on the magnitude of this error, the cooling water channel may not be able to make close contact with the circuit body and the printed circuit board, and cooling performance can be impaired. Furthermore, attempting to force close contact creates excessive stress in the circuit body, insulating film, or printed circuit board, which can cause fractures or cracks. The present invention was made with regard to the above problems and a main objective is to achieve a power conversion device that can improve reliability while efficiently cooling both a semiconductor element and a printed circuit board. Solution to the problem A power conversion device according to the present invention comprises: a semiconductor packing containing a semiconductor element; a printed circuit board containing a wiring layer connected to the semiconductor packing and having a pair of surfaces facing each other; a first heat dissipation element which is brought into contact with a heat dissipation surface of the semiconductor packing via a first thermal conducting element; and a second heat dissipation element which is brought into contact with a surface formed on the same side as the heat dissipation surface of the semiconductor packing under the pair of surfaces of the printed circuit board via a second thermal conducting element, wherein the first heat dissipation element and the second heat dissipation element are arranged in a state in which they are displaceable relative to each other, and the first thermal conducting element and the second thermal conducting element are arranged such that they partially overlap each other. Advantageous effects of the invention According to the present invention, it is possible to achieve a power conversion device that can improve reliability while efficiently cooling both the semiconductor element and the circuit board. Brief description of the drawings [ 1 ] 1 is a diagram that represents a cross-sectional structure of a power conversion device according to a first embodiment of the present invention.[ 2 ] 2 is a diagram that represents a cross-sectional structure of a power conversion device according to a second embodiment of the present invention.[ 3 ] 3 is a diagram that represents a cross-sectional structure of a power conversion device according to a third embodiment of the present invention.[ 4 ] 4 is a diagram that represents a cross-sectional structure of a power conversion dev