WO2017110540A1

WO2017110540A1 - Circuit structure

Info

Publication number: WO2017110540A1
Application number: PCT/JP2016/086848
Authority: WO
Inventors: 有室野井; 陳　登
Original assignee: 株式会社オートネットワーク技術研究所; 住友電装株式会社; 住友電気工業株式会社
Priority date: 2015-12-24
Filing date: 2016-12-12
Publication date: 2017-06-29
Also published as: JP2017117903A

Abstract

Provided is a circuit structure that exhibits excellent heat dissipation properties. The circuit structure 1 is equipped with: a substrate 10 having a conductive pattern 101 formed on one surface 10a thereof; a conductive member 20 affixed to the other surface 10b of the substrate 10; an electronic component 30 that has terminals 32, 33 that are electrically connected to the conductive member 20, also has a terminal 34 electrically connected to the conductive pattern 101 formed on the substrate 10, and is mounted onto the conductive member 20 via a first opening 11 formed in the substrate 10; and a first sealing member 40 that is provided between the electronic component 30 and the inner wall surface of the first opening 11.

Description

Circuit structure

The present invention relates to a circuit structure including a substrate and a conductive member.

A circuit configuration in which a conductive member (also called a bus bar or the like) constituting a circuit for conducting a relatively large current is fixed to a substrate on which a conductive pattern constituting a circuit for conducting a relatively small current is formed. The body is known (see, for example, Patent Document 1 below). The circuit structure includes an electronic component having a terminal connected to the conductive pattern and a terminal connected to the conductive member.

JP2015-99834A

This type of circuit structure is required to improve heat dissipation from the electronic components that generate heat in order to reduce the risk of failure of the electronic components.

The problem to be solved by the present invention is to provide a circuit structure that exhibits excellent heat dissipation.

In order to solve the above problems, a circuit structure according to the present invention includes a substrate having a conductive pattern formed on one surface, a conductive member fixed on the other surface side of the substrate, and an electrical connection to the conductive member. And an electronic component mounted on the conductive member through a first opening formed in the substrate, and a terminal electrically connected to a conductive pattern formed on the substrate, A first sealing member provided between the inner wall surface of the first opening and the electronic component.

In the circuit structure according to the present invention, when the electronic component is placed on the conductive member through the first opening formed in the substrate, the first sealing is provided between the inner wall surface of the first opening and the electronic component. A member is provided. In other words, since at least a part of the air layer in the first opening existing around the electronic component in the conventional circuit structure is replaced with the first sealing member, heat dissipation from the electronic component is dissipated. Can be improved.

A lead member disposed in the second opening formed in the conductive member and electrically connecting a part of the terminals of the electronic component and the conductive pattern formed in the substrate; A second sealing member that is provided between the wall surface and the lead member and covers at least one of a part of the terminal of the electronic component and the connection part of the lead member and the connection part of the substrate and the lead member It is good to provide.

With such a configuration, heat generated in the electronic component is transmitted to the conductive member via the lead member and the second sealing member, so that the heat dissipation can be further improved. In addition, the second sealing member may cause damage to the connection portion between the terminal and the lead member and the connection portion between the substrate and the lead member due to stress caused by heat, or a short circuit due to migration of a connection material such as solder. The fear can be reduced.

According to the present invention, a circuit structure excellent in heat dissipation can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is the figure (figure which showed the sealing member by cross-hatching) which showed typically the cross section (except an electronic component) of the part in which the electronic component in the circuit structure concerning 1st embodiment of this invention was mounted. It is an external view (figure which showed the sealing member by cross hatching) of the portion in which the electronic component in the circuit composition object concerning a first embodiment of the present invention was mounted. It is the figure (figure which showed the sealing member by cross hatching) which showed typically the section (except for electronic parts) of the portion in which the electronic parts in the circuit composition object concerning a second embodiment of the present invention were mounted. It is a top view (figure which showed the sealing member by cross hatching) of the portion in which the electronic component in the circuit composition object concerning a second embodiment of the present invention was mounted. It is a bottom view (figure which showed a sealing member by cross hatching) of a portion in which an electronic component was mounted in a circuit composition object (state which removed a heat dissipation member) concerning a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Unless otherwise specified, the plane direction in the following description refers to the plane direction of the substrate 10 and the conductive member 20, and the height direction (vertical direction) is a direction perpendicular to the plane direction (electrons on the substrate 10). The surface on which the component 30 is mounted is the upper side). These directions do not limit the installation direction of the circuit structure 1.

1 and 2 includes a circuit board 1, a conductive member 20, an electronic component 30, and a sealing (filling) member (hereinafter, a second sealing member 60 described later). To be distinguished from the first sealing member 40). The substrate 10 has a conductive pattern 101 formed on one surface 10a (upper surface). The conductive path formed by the conductive pattern 101 is a control conductive path (a part of the circuit), and the current flowing is smaller than the conductive path (a part of the circuit) formed by the conductive member 20.

The conductive member 20 has a portion along the plane direction fixed to the other surface 10 b (lower surface) of the substrate 10. A terminal portion (not shown) for connecting to an external electrical element may be provided. Below, the part along a plane direction is demonstrated as the electrically-conductive member 20. FIG. The conductive member 20 is formed by forming a conductive plate material into a predetermined shape by pressing or the like. The conductive member 20 constitutes a conductive path for power, which is a portion through which a relatively large current (larger than the conductive path constituted by the conductive pattern 101) flows. In addition, although detailed description and illustration are abbreviate | omitted about the specific shape of a conductive path, etc., the conductive member 20 is divided | segmented into the several conductor 21 which comprises each conductive path. The respective conductors 21 are individually independent so as not to be short-circuited, and are integrated by being fixed to the substrate 10. The conductors 21 are connected by the extra length before being fixed to the substrate 10, and after being fixed to the substrate 10, the extra length is cut off so that they are separated and independent from each other (not in direct contact). ) The conductive member 20 (conductor 21) is also referred to as a bus bar (bus bar plate) or the like. The conductive member 20 (conductor 21) is fixed to the other surface 10b of the substrate 10 through, for example, an insulating adhesive or an adhesive sheet. Thereby, the board | substrate 10 and the electrically-conductive member 20 are integrated, and 20 sets of board | substrates 10 and an electrically-conductive member are obtained.

The electronic component 30 is an element mounted on the substrate 10 and the conductive member 20 set, and has an element body 31 and a terminal. A plurality of electronic components 30 are mounted on the set of the substrate 10 and the conductive member 20. The specific electronic component 30 has a plurality of types of terminals, a part of which is electrically and physically connected to the conductive pattern 101 formed on the substrate 10 and the other part to the conductive member 20 (conductor 21). Is done. In the present embodiment, the electronic component 30 (element main body 31) is supported on the conductive member 20 through an opening formed in the substrate 10 (hereinafter referred to as the first opening 11 to be distinguished from a second opening 22 described later). . The first terminal 32 located on one side of the element body 31 and the second terminal 33 located on the other side are connected to the conductive member 20, and the third terminal 34 located on the other side is connected to the conductive pattern 101 ( Land). Since the conductor 21 to which the first terminal 32 is connected and the conductor 21 to which the second terminal 33 is connected are separated, both terminals are not short-circuited. The electronic component 30 may have a plurality of at least one of the first terminal 32 to the third terminal 34. An example of such an electronic component 30 is a transistor (FET). The first terminal 32 corresponds to a drain terminal, the second terminal 33 corresponds to a source terminal, and the third terminal 34 corresponds to a gate terminal.

Note that there may be another electronic component in which all terminals are directly electrically connected to the conductive pattern 101 formed on the substrate 10 or electrically connected to the conductive member 20.

The first sealing member 40 is provided between the inner wall surface of the first opening 11 and the electronic component 30 accommodated in the first opening 11. The first sealing member 40 may be provided so as to connect at least the inner wall surface of the first opening 11 and the element main body 31 of the electronic component 30. The first sealing member 40 in the present embodiment is provided so as to fill the entire first opening 11 (except for the place where the electronic component 30 is located). Accordingly, the first sealing member 40 covers the connection portion of the first terminal 32 or the second terminal 32 and the conductive member 20 (each conductor 21).

In order to prevent a short circuit, the first sealing member 40 is made of an insulating material. In the present embodiment, a base material 401 made of a resin material (for example, a thermoplastic resin material such as PBT or PPS) is filled with a filler 402 (for example, ceramic or aluminum oxide) made of an insulating material having high thermal conductivity. It becomes. As the filler 402, a material having a higher thermal conductivity than at least the material constituting the base material 401 is selected. Thereby, it is possible to improve thermal conductivity as compared with the case where the entire first sealing member 40 is formed of a material constituting the base material 401. Moreover, the linear expansion coefficient, rigidity, etc. of the 1st sealing member 40 can be adjusted by changing the kind and quantity of the filler 402. FIG.

Further, in the circuit structure 1 according to the present embodiment, the heat radiating member 50 is joined to the lower surface of the conductive member 20 (the surface on the opposite side to the substrate 10 side). The conductive member 20 and the heat radiating member 50 are joined through, for example, an insulating adhesive sheet. Any form (such as the presence or absence of fins) of the heat radiating member 50 may be used. When such a heat radiating member 50 is joined, the heat radiating member 50 constitutes the bottom surface of the first opening 11. Thus, if the lower surface of the first opening 11 is sealed, the operation of filling the first sealing member 40 into the first opening 11 becomes easy. That is, the heat radiating member 50 serves not only to improve the heat radiating property but also to facilitate the filling operation of the first sealing member 40.

In the present embodiment, the first sealing member 40 is also filled in the gaps 23 between the plurality of conductors 21 constituting the conductive member 20. In this way, since the insulation between the conductors 21 is enhanced by the insulating second sealing member 60, the gap 23 between the conductors 21 can be reduced.

As described above, in the circuit structure 1 according to the present embodiment, the electronic component 30 is placed on the conductive member 20 through the first opening 11 formed in the substrate 10. A first sealing member 40 is provided between the wall surface and the electronic component 30. In other words, since at least a part of the air layer in the first opening 11 existing around the electronic component 30 in the conventional circuit structure is replaced with the first sealing member 40, it is generated from the electronic component 30. The heat dissipation of the heat to be performed can be improved (the heat buildup on the electronic component 30 is suppressed by the air layer). The configuration in which the first sealing member 40 is embedded in the entire first opening 11 as in the present embodiment is a preferable aspect in terms of heat dissipation (since there is no air layer in the first opening 11). It can be said that there is.

Moreover, in this embodiment, since the connection part of the 1st terminal 32 or the 2nd terminal 32, and the electrically-conductive member 20 (each conductor 21) is also covered by the 1st sealing member 40, the said heat | fever generate | occur | produces with the heat | fever generate | occur | produced from the electronic component 30 The risk of damage to the connecting portion is reduced.

The circuit structure 2 according to the second embodiment will be described focusing on differences from the circuit structure 1 according to the first embodiment. The circuit structure 2 according to this embodiment is different from the first embodiment in the structure for electrically connecting the third terminal 34 of the electronic component 30 and the conductive pattern 101 formed on the substrate 10. Specifically, it is as follows.

3 to FIG. 5 includes a lead member 70 for electrically connecting the third terminal 34 and the conductive pattern 101 formed on the substrate 10. The conductive member 20 is formed with an opening for arranging the lead member 70 (referred to as the second opening 22 to distinguish from the first opening 11). The second opening 22 in the present embodiment is a notch formed in at least a part of the conductor 21 constituting the conductive member 20. It can also be said that this is a portion in which a part of the space between the two conductors 21 is enlarged.

When the electronic component 30 (element body 31) is placed on the conductive member 20 in the same manner as in the first embodiment, the third terminal 34 is provided so as to overlap the second opening 22 in the vertical direction. That is, the second opening 22 is provided below the third terminal 34. Therefore, the conductive member 20 does not exist below the third terminal 34, and the third terminal 34 is exposed. One end side of the lead member 70 is connected to the exposed third terminal 34. The lead member 70 is located in the second opening 22 and is not in contact with the conductive member 20.

In addition, the other surface 10b (lower surface) of the substrate 10 is provided with a connecting portion 12 (land) electrically connected to the conductive pattern 101 formed on the one surface 10a (upper surface). The connection portion 12 and the conductive pattern 101 are electrically connected through a through hole 121 formed so as to penetrate the substrate 10. The connecting portion 12 formed on the substrate 10 overlaps with the second opening 22 of the conductive member 20 in the vertical direction. That is, the conductive member 20 does not exist below the connection portion 12 and the connection portion 12 is exposed. The other end side of the lead member 70 is connected to the exposed connection portion 12.

Thus, the third terminal 34 of the electronic component 30 is electrically connected to the conductive pattern 101 formed on the substrate 10 via the lead member 70 disposed in the second opening 22 formed in the conductive member 20. Has been. In the first embodiment, the third terminal of the electronic component 30 is directly connected to the conductive pattern 101. In the present embodiment, the third terminal 34 of the electronic component 30 is indirectly connected via the lead member 70. They differ in that they are connected.

In the present embodiment, the second opening 22, which is a space where the lead member 70 is disposed (a space for preventing the third terminal 34 and the connecting portion 12 from contacting the conductive member 20), is sealed with an insulating material. A stop (filling) member is filled (hereinafter referred to as the second sealing member 60 in order to distinguish from the first sealing member 40). The material of the second sealing member 60 is preferably excellent in thermal conductivity, and may be the same as or different from the first sealing member 40. If the first sealing member 40 and the second sealing member 60 are made of the same material, the first opening 11 and the second opening 22 are connected spaces. A member can be formed.

In the second opening 22, a connection portion between the third terminal 34 and the lead member 70 and a connection portion between the lead member 70 and the connection portion 12 are located. It is provided so as to cover at least one of them. The second sealing member 60 is provided between the inner wall surface of the second opening 22 and the lead member 70 (so as to connect the inner wall surface of the second opening 22 and the lead member 70). The 2nd sealing member 60 in this embodiment is provided so that both connection parts may be covered. More specifically, the second sealing member 60 in the present embodiment is provided so as to fill the entire second opening 22. If the heat dissipation member 50 as described in the first embodiment is provided on the lower surface of the conductive member 20 (the surface opposite to the substrate 10), the lower surface of the second opening 22 is blocked by the heat dissipation member 50. There is also an advantage that the operation of filling the second sealing member 60 into the second opening 22 is facilitated.

Also in this embodiment, the sealing member (the first sealing member 40 or the second sealing member 60) is also filled in the gaps 23 between the plurality of conductors 21 constituting the conductive member 20. In this way, since the insulation between the conductors 21 is enhanced by the insulating second sealing member 60, the gap 23 between the conductors 21 can be reduced.

According to the circuit configuration body 2 according to the second embodiment described above, the heat generated in the electronic component 30 is transmitted to the conductive member 20 via the lead member 70 and the second sealing member 60 ( Since the air layer between the lead member 70 and the inner wall surface of the second opening 22 is replaced with the second seal member 60), heat dissipation can be improved. The configuration in which the second sealing member 60 is embedded in the entire second opening 22 as in the present embodiment is a preferable aspect in terms of heat dissipation (since there is no air layer in the second opening 22). It can be said that there is. Further, the second sealing member 60 may damage the connection portion between the third terminal 34 and the lead member 70 or the connection portion between the substrate 10 (connection portion 12) and the lead member 70 due to heat generated stress, or soldering. The possibility that a short circuit or the like due to migration of the connection material such as the above will occur can be reduced.

As mentioned above, although embodiment (and its modification) of this invention was described in detail, this invention is not limited to the said embodiment (and its modification) at all, and in the range which does not deviate from the summary of this invention. Various modifications are possible.

DESCRIPTION OF

SYMBOLS

1, 2 Circuit structure 10 Board | substrate 10a One surface 10b The other surface 11 First opening 12 Connection part 101 Conductive pattern 20 Conductive member 21 Conductor 22 Second opening 30 Electronic component 31 Element main body 32 First terminal 33 Second terminal 34 Third terminal 40 First sealing member 60 Second sealing member 70 Lead member

Claims

A substrate having a conductive pattern formed on one surface;
A conductive member fixed to the other surface side of the substrate;
A terminal electrically connected to the conductive member and a terminal electrically connected to a conductive pattern formed on the substrate, and placed on the conductive member through a first opening formed in the substrate Electronic components,
A first sealing member provided between the inner wall surface of the first opening and the electronic component;
A circuit structure comprising:
A lead member that is disposed in a second opening formed in the conductive member and electrically connects a part of the terminals of the electronic component and the conductive pattern formed on the substrate;
At least one of a part of the terminal of the electronic component and the connection part of the lead member, and a connection part of the substrate and the lead member provided between the inner wall surface of the second opening and the lead member A second sealing member covering;
The circuit structure according to claim 1, comprising: