Electric connection unit

Abstract

To provide an electric connection unit which enables improvement of heat radiation performance.SOLUTION: An electric connection unit according to one embodiment includes: a base part; bus bars; electronic components; and one or more heat conduction parts. The base part has a plate or sheet-like plane part. The plane part is formed with one or more first housing parts which are recessed in a thickness direction of the plane part or penetrates through the plane part in the thickness direction. The bus bars are held by the plane part. The electronic components face the base member and are electrically connected to the bus bars. The heat conduction parts are electrically separated from the bus bars and the electronic components and are held by the base member, respectively housed in the first housing parts. The heat conduction parts are more excellent in heat conductivity than the base member.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to an electrical connection unit. [Background technology]

[0002] Electrical connection units comprising a plurality of electronic components are known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-037492 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, electrical connection units are expected to have improved heat dissipation properties.

[0005] One embodiment provides an electrical connection unit that allows for improved heat dissipation. [Means for solving the problem]

[0006] An electrical connection unit according to one embodiment includes a base portion, a bus bar, an electronic component, and a heat conductive portion. The base portion has a plate- or sheet-shaped flat portion. A first housing portion is formed in the flat portion, the first housing portion being recessed in the thickness direction of the flat portion or penetrating the thickness direction of the flat portion. The bus bar is held in the flat portion. The electronic component faces the base member and is electrically connected to the bus bar. The heat conductive portion is electrically isolated from the bus bar and the electronic component, and is held by the base member while being housed in the first housing portion. The heat conductive portion has superior thermal conductivity to the base member. [Effects of the Invention]

[0007] According to one embodiment, an electrical connection unit capable of improving heat dissipation can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view showing the electrical connection unit of the first embodiment. [Figure 2] FIG. 2 is a perspective view illustrating a main body of the first embodiment. [Figure 3] FIG. 2 is a perspective view illustrating a subunit according to the first embodiment. [Figure 4] FIG. 2 is a partially exploded perspective view of the subunit of the first embodiment. [Figure 5] FIG. 2 is a perspective view showing the wiring board of the first embodiment. [Figure 6] FIG. 2 is a partially exploded perspective view of the wiring board according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view corresponding to line F7-F7 in FIG. [Figure 8] FIG. 2 is a plan view showing the wiring board of the first embodiment. [Figure 9] FIG. 2 is a partially exploded perspective view of the electrical connection unit according to the first embodiment. [Figure 10] FIG. 2 is a bottom view showing the wiring board of the first embodiment. [Figure 11] 9 is a cross-sectional view of the structure shown in FIG. 8 taken along line F11-F11. [Figure 12] 12 is a cross-sectional view of the electrical connection unit according to the second embodiment, corresponding to FIG. 11. FIG. [Figure 13] FIG. 11 is a bottom view of the wiring board according to the third embodiment. [Figure 14] 14 is a cross-sectional view corresponding to F14-F14 in FIG. [Figure 15] FIG. 15 is a cross-sectional view of a modified example of the third embodiment, corresponding to FIG. [Figure 16] FIG. 15 is a cross-sectional view of a modified example of the third embodiment, corresponding to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components having the same or similar functions will be assigned the same reference numerals. Duplicate descriptions of those components may be omitted. Note that the specific configurations described below do not limit the applicable scope of the embodiments.

[0010] In this disclosure, terms are defined as follows: "Connection" is not limited to mechanical connection and may include electrical connection. In other words, "connection" is not limited to direct connection between two elements to be connected, but may include connection between two elements via another element interposed therebetween. "Containment" is not limited to containment of the entire component, but may include containment of only a portion of the component. "Facing" means that virtual projection images of two objects overlap when viewed from a specific direction. In other words, "facing" is not limited to two objects directly facing each other, but may include cases where two objects face each other with another component interposed between them. "Parallel," "orthogonal," or "same" may include cases where "substantially parallel," "substantially perpendicular," or "substantially the same," respectively.

[0011] In the present disclosure, the +X direction, the −X direction, the +Y direction, the −Y direction, the +Z direction, and the −Z direction are defined as follows: The +X direction is the direction from the first end 80e1 to the second end 80e2 of the metal plate 80 (described later) (see FIG. 9 ). The −X direction is the direction opposite to the +X direction. Hereinafter, when there is no need to distinguish between the +X direction and the −X direction, they will simply be referred to as the “X direction.” The +Y direction and the −Y direction are directions that intersect (e.g., are perpendicular to) the X direction. The +Y direction is the direction from the third end 80e3 to the fourth end 80e4 of the metal plate 80 (described later) (see FIG. 9 ). The −Y direction is the direction opposite to the +Y direction. Hereinafter, when there is no need to distinguish between the +Y direction and the −Y direction, they will simply be referred to as the “Y direction.” The +Z direction and the −Z direction are directions that intersect (e.g., are perpendicular to) the X direction and the Y direction. The +Z direction is the direction from the metal plate 80 described later toward the main body portion MU (see FIG. 1). The -Z direction is the direction opposite to the +Z direction. Hereinafter, when there is no need to distinguish between the +Z direction and the -Z direction, they will simply be referred to as the "Z direction." The Z direction is an example of the "thickness direction."

[0012] In the following, when there is no distinction between the X direction and the Y direction, they may be referred to as the "horizontal direction." In the following, the Z direction may be referred to as the "vertical direction." In addition, in the following, the +Z direction side may be referred to as "up" and the -Z direction side may be referred to as "down." However, these expressions are used for the convenience of explanation and do not limit the direction of gravity of the electrical connection unit 1 (the installation posture of the electrical connection unit 1).

[0013] <1. Configuration of Electrical Connection Unit 1> FIG. 1 is a cross-sectional view showing an electrical connection unit 1 according to an embodiment. 1 is an in-vehicle device mounted on a vehicle such as an EV (Electric Vehicle), an HEV (Hybrid Electric Vehicle), or a PHEV (Plug-in Hybrid Electric Vehicle). The electrical connection unit 1 may also be referred to as an "electrical connection box" or a "junction box." However, the electrical connection unit 1 is not limited to a box-shaped device.

[0014] The electrical connection unit 1 includes, for example, a main body MU, a metal plate 80, an insulating sheet 91 (see FIG. 11), a plurality of heat transfer members 92, and an insulating cover 93.

[0015] <2. Main body MU> First, the main body MU will be described. FIG. 2 is a perspective view for explaining the main body MU. The main body MU shown in FIG. 2 is a part that performs the main function of the electrical connection unit 1 (for example, switching the electrical connection state or overcurrent protection). The main body MU is divided into, for example, multiple subunits SU. The main body MU is formed, for example, by connecting multiple subunits SU. In this embodiment, the main body MU has three subunits SU (first to third subunits SUX, SUY, SUZ). Each subunit SU may be referred to as a "circuit assembly."

[0016] The first subunit SUX has a first electrical function. The first subunit SUX includes, for example, a plurality of electronic components 10X and a first wiring board 40X. The plurality of electronic components 10X are electrically connected to the first wiring board 40X.

[0017] The second subunit SUY has a second electrical function. The second function is different from the first function. The second subunit SUY includes, for example, a plurality of electronic components 10Y and a second wiring board 40Y. The plurality of electronic components 10Y are electrically connected to the second wiring board 40Y.

[0018] The third subunit SUZ has a third electrical function. The third function is different from the first and second functions. The third subunit SUZ includes, for example, a plurality of electronic components 10Z and a third wiring board 40Z. The plurality of electronic components 10Z are electrically connected to the third wiring board 40Z.

[0019] In this embodiment, the three subunits SUX, SUY, and SUZ are arranged side by side in the X direction. For example, the first subunit SUX is arranged on the +X direction side of the second subunit SUY. The first subunit SUX and the second subunit SUY are electrically connected via a coupling bus bar 75 that extends between the first routing board 40X and the second routing board 40Y. On the other hand, the third subunit SUZ is arranged on the -X direction side of the second subunit SUY. The third subunit SUZ and the second subunit SUY are electrically connected via a coupling bus bar 75 that extends between the third routing board 40Z and the second routing board 40Y. The coupling bus bar 75 is arranged on the opposite side of the metal plate 80 from the multiple subunits SU.

[0020] In this embodiment, the three wiring boards 40X, 40Y, and 40Z included in the three subunits SUX, SUY, and SUZ are arranged on the same plane. In other words, the three wiring boards 40X, 40Y, and 40Z are arranged at the same height in the Z direction. The three wiring boards 40X, 40Y, and 40Z form one large wiring board 40M.

[0021] In this embodiment, the three subunits SUX, SUY, and SUZ have the same or similar basic structures. Therefore, the following detailed description will focus on one subunit SU. Hereinafter, when there is no need to distinguish between the first subunit SUX, the second subunit SUY, and the third subunit SUZ, they will simply be referred to as "subunits SU." Furthermore, when there is no need to distinguish between the electronic component 10X, the electronic component 10Y, and the electronic component 10Z, they will simply be referred to as "electronic component 10." Furthermore, when there is no need to distinguish between the first routing board 40X, the second routing board 40Y, and the third routing board 40Z, they will simply be referred to as "routing board 40."

[0022] <3. Structure of the subunit SU> Next, the configuration of the subunit SU will be described. Fig. 3 is a perspective view for explaining the subunit SU, and Fig. 4 is a perspective view showing a part of the subunit SU in an exploded state. As shown in Figures 3 and 4, the subunit SU includes, for example, a plurality of electronic components 10, a plurality of connection components 20 for component connection, a plurality of connection components 30 for external connection, a wiring board 40, a plurality of fastening members 71, 72, 73, and a connection component 100 for unit connection (see Figure 2).

[0023] <3.1 Electronic component 10 and connecting component 20> First, the electronic component 10 and the connection component 20 will be described. The electronic component 10 is an electronic component that is mounted on the subunit SU according to the functions required of the subunit. The electronic component 10 is, for example, a connector, a fuse, a relay (e.g., a mechanical relay or a semiconductor relay), a capacitor, a branching component, various sensors (e.g., a current sensor or a voltage sensor), an electronic control unit, or an electronic component unit that combines two or more of these. Note that the type of electronic component 10 is not limited to the above examples. The electronic component 10 is, for example, a heat-generating component that generates heat when powered on.

[0024] The connection part 20 is a part that electrically connects the electronic component 10 and the wiring board 40. The connection part 20 forms part of the current path in the subunit SU. The connection part 20 is made of metal (e.g., copper or a copper alloy). The connection part 20 is provided standing upright on the +Z direction side from the wiring board 40. A first end (the end on the -Z direction side) of the connection part 20 is connected to the bus bar 42 by a fastening member 43 (e.g., a bolt). A second end (the end on the +Z direction side) of the connection part 20 is connected to the electronic component 10 by a fastening member 71 (e.g., a screw or a bolt).

[0025] <3.2 External connection parts 30> Next, the connecting part 30 for external connection will be described. The connection component 30 is a component that electrically connects the external connection bus bar 76 and the wiring board 40. In this embodiment, the connection component 30 electrically connects the external connection bus bar 76 and the bus bar 42 included in the wiring board 40. The external connection bus bar 76 is electrically connected to an external device. In this disclosure, the term "external device" refers to an electrical device that exists outside the electrical connection unit 1. The external device is, for example, a battery unit mounted on a vehicle or an inverter for driving a motor of the vehicle. However, the external device is not limited to a battery unit or an inverter.

[0026] Like the connection component 20, the connection component 30 is made of metal (for example, copper or a copper alloy). As shown in FIG. 2, the connection component 30 is provided in an upright state on the +Z direction side at the outer periphery (X direction end) of the wiring board 40M. A first end (-Z direction end) of the connection component 30 is connected to the bus bar 42 by a fastening member 43 (for example, a bolt). A second end (+Z direction end) of the connection component 20 is connected to the external connection bus bar 76 by a fastening member 73 (for example, a screw or a bolt).

[0027] <3.3 Connection parts 100 for unit connection> Next, the connecting part 100 for connecting units will be described. 2, the connection part 100 electrically connects adjacent subunits SU to each other. In this embodiment, the connection part 100 connects between the bus bar 42 included in one of the adjacent subunits SU (for example, the second subunit SUY) and the bus bar 42 included in the other subunit SU (for example, the third subunit SUZ).

[0028] <3.4 Wiring board 40> First, the wiring board 40 will be described. FIG. 5 is a perspective view showing the wiring board 40. As shown in FIG. As shown in FIG. 5 , the wiring board 40 is a member that forms at least a portion of the electrical paths between multiple electronic components 10 and / or at least a portion of the electrical paths between the electronic components 10 and an external device. In this disclosure, the term "wiring board" refers to a board-type wiring structure. "Board-type" refers to a plate-like structure that is flat when viewed as a whole, regardless of its detailed shape. In this disclosure, "plate-like," "sheet-like," or "flat" does not necessarily mean a completely flat structure, but may also include a surface that has a fixing structure or rib protruding in the Z direction or an uneven surface that conforms to the thickness of the bus bar. In this embodiment, the wiring board 40 is a plate-like structure that is flat along the X and Y directions.

[0029] The wiring board 40 includes, for example, a base plate 41, one or more (e.g., a plurality of) bus bars 42, a plurality of fastening members 43, and one or more (e.g., a plurality of) heat conductive portions 45. In this embodiment, the base plate 41, the plurality of bus bars 42, and the plurality of heat conductive portions 45 are integrated by insert molding. For example, the wiring board 40 is formed as a single member by insert molding the bus bars 42 and the heat conductive portions 45 with the base plate 41 after the fastening members 43 are fixed to the bus bars 42. That is, the bus bars 42 and the heat conductive portions 45 are integrated with the base plate 41 without using fastening members such as screws or bolts. Note that the wiring board 40 may be formed using a structure other than insert molding. Alternatively, one of the bus bars 42 and the heat conductive portions 45 may be integrated with the base plate 41 by insert molding, and the other may be provided on the base plate 41 by a method other than insert molding. The base plate 41 is an example of a "base member."

[0030] 6 is a partially exploded perspective view of the wiring board 40. For ease of explanation, the base plate 41, the bus bar 42, and the fastening member 43 will be described below with reference to the partially exploded view of the wiring board 40.

[0031] (Base plate 41) As shown in FIG. 6 , the base plate 41 is a holding member that integrally holds a plurality of bus bars 42 that are arranged horizontally at intervals from one another. The base plate 41 is made of, for example, a synthetic resin and has insulating properties. The base plate 41 is formed, for example, in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the lateral direction. The base plate 41 electrically insulates the plurality of bus bars 42 from one another. The base plate 41 has, for example, a flat portion 51 and a plurality of fixing portions 52.

[0032] The flat surface portion 51 is a plate-shaped portion of the base plate 41. The flat surface portion 51 forms the main portion of the base plate 41. The flat surface portion 51 extends in the horizontal direction. In this embodiment, the flat surface portion 51 extends across the entire width of the base plate 41 in the X direction and across the entire width of the base plate 41 in the Y direction, excluding the four corners of the base plate 41.

[0033] The flat portion 51 has a first surface 51a and a second surface 51b. The first surface 51a is a surface facing the +Z direction. The first surface 51a is a flat surface extending along the horizontal direction. The first surface 51a faces the multiple electronic components 10 and also faces the insulating cover 93 (see FIG. 1) of the electrical connection unit 1. The second surface 51b is located on the opposite side to the first surface 51a. The second surface 51b is a surface facing the -Z direction. The second surface 51b is a flat surface extending along the horizontal direction. The second surface 51b faces the metal plate 80 (see FIG. 1). The thickness direction (plate thickness direction) of the flat portion 51 is the Z direction.

[0034] The flat portion 51 is formed with one or more (e.g., multiple) accommodating portions 55, each accommodating a bus bar 42, for example. The multiple accommodating portions 55 are formed spaced apart from one another in the X direction or the Y direction. Each accommodating portion 55 is, for example, a through-hole penetrating the flat portion 51 in the Z direction. That is, each accommodating portion 55 is open in the Z direction on both the first surface 51a and the second surface 51b. Note that instead of a through-hole, the accommodating portion 55 may be a recess provided on the first surface 51a or the second surface 51b of the flat portion 51 and recessed in the Z direction. Note that in the present disclosure, the phrase "the accommodating portion penetrates the flat portion in the first direction (Z direction)" may also include a case where only a portion of the entire length of the accommodating portion 55 penetrates the flat portion 51 in the Z direction (for example, the remaining portion of the accommodating portion 55 may be a recess recessed in the Z direction, or may be provided inside the base plate 41 and not exposed to the outside of the base plate 41). Similarly, in the present disclosure, "the storage section is recessed in the first direction (Z direction)" may also include a case where a portion of the entire length of storage section 55 is recessed in the Z direction (for example, the remaining portion of storage section 55 may be a through-hole that penetrates flat section 51 in the Z direction, or may be provided inside base plate 41 and not exposed to the outside of base plate 41). Storage section 55 is an example of a "second storage section."

[0035] 6, when viewed from the Z direction, each accommodating portion 55 is formed to have an outer shape corresponding to the shape of the bus bar 42 to be accommodated. In the present embodiment, the planar portion 51 includes, as the plurality of accommodating portions 55, for example, five accommodating portions 55A, 55B, 55C, 55D, and 55E.

[0036] A through hole 51h is formed in the flat portion 51 at a position offset in the X direction or Y direction from the accommodation portion 55. As shown in FIG. 4 , the through hole 51h is formed at a position overlapping, for example, the mounting portion 14 of the electronic component 10 when viewed from the Z direction. The mounting portion 14 is a portion for mounting the electronic component 10 to the metal plate 80. The mounting portion 14 protrudes in the X direction or Y direction from the end of the case of the electronic component 10 on the −Z direction side.

[0037] The flat surface portion 51 is formed with one or more (e.g., multiple) accommodation portions 56 that each accommodate a heat conduction portion 45. The multiple accommodation portions 56 are formed at positions on the flat surface portion 51 that are offset in the X direction or Y direction with respect to the accommodation portion 55 of the bus bar 42 and the through hole 51h. Each accommodation portion 56 is, for example, a through hole that penetrates the flat surface portion 51 in the Z direction. That is, each accommodation portion 56 is open in the Z direction on both the first surface 51a and the second surface 51b. Note that instead of through holes, the accommodation portions 56 may be recesses that are provided on the first surface 51a or the second surface 51b of the flat surface portion 51 and recessed in the Z direction.

[0038] When viewed from the Z direction, each of the accommodating portions 56 is formed to have an outer shape corresponding to the shape of the heat conducting portion 45 to be accommodated. In the present embodiment, the planar portion 51 includes, as the plurality of accommodating portions 56, for example, five accommodating portions 56A, 56B, 56C, and 56D.

[0039] FIG. 7 is a cross-sectional view taken along line F7-F7 in FIG. 4 and 7, the fixing portion 52 is a portion used to fix the metal plate 80 to the base plate 41. The fixing portion 52 is provided at a corner of the base plate 41. The fixing portion 52 includes, for example, an upright plate portion 52a and a horizontal plate portion 52b.

[0040] The standing plate portion 52a stands upright in the +Z direction from an end of the flat portion 51 of the base plate 41. When viewed from the Z direction, the standing plate portion 52a is formed, for example, in an L shape. That is, the standing plate portion 52a extends in the Z direction with a portion of the horizontal direction open. The horizontal plate portion 52b extends horizontally from the end of the upright plate portion 52a on the +Z direction side. The horizontal plate portion 52b is a plate portion that extends horizontally. The horizontal plate portion 52b extends like an eave so as to cover the area surrounded by the upright plate portion 52a from the +Z direction side.

[0041] (Busbar 42) As shown in FIGS. 5 and 6 , busbars 42 are routing members (electrical connection members) included in routing board 40. Busbars 42 are, for example, routing members for electrically connecting multiple electronic components 10 together. Busbars 42 may also be routing members for connecting one electronic component 10 to an external device. Busbars 42 are made of metal (for example, copper or a copper alloy) and are electrically conductive. In this embodiment, routing board 40 has multiple busbars 42, for example, five busbars 42A, 42B, 42C, 42D, and 42E. The five busbars 42A, 42B, 42C, 42D, and 42E are arranged horizontally at intervals from one another. The five busbars 42A, 42B, 42C, 42D, and 42E are held by flat portion 51 of base plate 41.

[0042] At least a portion of each bus bar 42 is a plate-like shape extending in the horizontal direction. At least a portion of each bus bar 42 extends along the flat portion 51 while housed in the housing portion 55. At least a portion of each bus bar 42 extends along the first surface 51a of the flat portion 51. At least a portion of each bus bar 42 extends in the horizontal direction within the housing portion 55. In the present embodiment, each bus bar 42 is a plate-like shape extending in the horizontal direction over the entire bus bar 42. Each bus bar 42 extends along the flat portion 51 while housed in the housing portion 55 over the entire length of the bus bar 42. Hereinafter, the portion of each bus bar 42 housed in the housing portion 55 (the portion extending along the flat portion 51) may be referred to as the "plate portion 42p."

[0043] FIG. 8 is a plan view showing the wiring board 40. As shown in FIG. As shown in FIG. 8, the plate portion 42p of each bus bar 42 has, for example, a first connection portion 61, a second connection portion 62, and an extension portion 63.

[0044] The first connection portion 61 is a portion that contacts one of the multiple connection components 20 (hereinafter referred to as the "first connection component 20"). The first connection component 20 is a connection component that connects one of the multiple electronic components 10 (hereinafter referred to as the "first electronic component 10") to the bus bar 42. The first connection portion 61 is a portion of the bus bar 42 that overlaps with the first connection component 20 when viewed from the Z direction. The first connection portion 61 is adjacent to the first connection component 20 in the Z direction. The first connection portion 61 is connected to the first connection component 20 from the Z direction.

[0045] The second connection portion 62 is a portion that comes into contact with a connection portion 20 (hereinafter referred to as the "second connection portion 20") different from the first connection portion 20 among the multiple connection portions 20. The second connection portion 20 is a connection portion that connects an electronic component 10 (hereinafter referred to as the "second electronic component 10") different from the first electronic component 10 among the multiple electronic components 10 to the bus bar 42. The second connection portion 62 is a portion of the bus bar 42 that overlaps with the second connection portion 20 when viewed from the Z direction. The second connection portion 62 is adjacent to the second connection portion 20 in the Z direction. The second connection portion 62 is connected to the second connection portion 20 from the Z direction.

[0046] The second connection portion 62 may be a portion that comes into contact with the connection component 30. The connection component 30 is a connection component for connecting an external device and the bus bar 42. In this case, the second connection portion 62 is a portion of the bus bar 42 that overlaps with the connection component 30 when viewed from the Z direction. The second connection portion 62 is adjacent to the connection component 30 in the Z direction. The second connection portion 62 is connected to the connection component 30 from the Z direction.

[0047] The second connection portion 62 may be a portion that contacts the coupling bus bar 75 for connecting to another subunit SU, instead of the connection parts 20, 30. In this case, the second connection portion 62 is a portion of the bus bar 42 that overlaps with the coupling bus bar 75 when viewed from the Z direction. The second connection portion 62 is adjacent to the coupling bus bar 75 in the Z direction. The second connection portion 62 is connected to the coupling bus bar 75 from the Z direction.

[0048] The extending portion 63 extends in the X direction or the Y direction from the first connecting portion 61. The extending portion 63 is provided between the first connecting portion 61 and the second connecting portion 62. The extending portion 63 extends across the first connecting portion 61 and the second connecting portion 62. The extending portion 63 connects the first connecting portion 61 and the second connecting portion 62.

[0049] In this embodiment, the first connection portion 61, the second connection portion 62, and the extension portion 63 are plate-shaped and extend horizontally. In this embodiment, each busbar 42 extends along the flat portion 51 while being housed in the housing portion 55, spanning at least the first connection portion 61 and the second connection portion 62. For example, the first connection portion 61, the second connection portion 62, and the extension portion 63 extend along the flat portion 51 while being housed in the housing portion 55. The portion of each busbar 42 housed in the housing portion 55 is exposed on the first surface 51a and the second surface 51b of the flat portion 51. That is, the surface of each busbar 42 facing the Z direction is exposed to the outside of the base plate 41 (e.g., in the +Z direction and the −Z direction) through the opening of the housing portion 55. However, a portion of the busbar 42 may be buried in the base plate 41.

[0050] In this embodiment, the extension portions 63 of some bus bars 42 are accommodated in the accommodation portion 55, and extend through the region R that overlaps with the electronic component 10 when viewed from the Z direction, so as to span both sides of the region R. For example, the extension portions 63 extend linearly in the X direction. The extension portions 63 extend through the region R that overlaps with the electronic component 10 when viewed from the Z direction, so as to span both the +X direction side and the −X direction side of the region R.

[0051] Furthermore, one or more bus bars 42 may have an extension portion 64 in addition to the first connection portion 61, the second connection portion 62, and the extension portion 63. The extension portion 64 is a portion of the bus bar 42 extended for the purpose of increasing the heat dissipation area and / or the heat capacity for heat storage (heat absorption). The extension portion 64 is a portion not used for electrical connection. For example, the extension portion 64 is located on the opposite side of the extension portion 63 from the first connection portion 61 (or the second connection portion 62). The extension portion 64 has a plate shape extending horizontally. The extension portion 64 extends along the flat portion 51 when housed in the housing portion 55. When housed in the housing portion 55, the extension portion 64 extends to a region R that overlaps with the electronic component 10 when viewed from the Z direction. The extension portion 64 has an end 42e1 of the bus bar 42 at a position that overlaps with the region R when viewed from the Z direction.

[0052] The following describes several examples of wiring the bus bars 42. The plurality of electronic components 10 includes three electronic components 10A, 10B, and 10C. The plurality of connection components 20 includes six connection components 20A, 20B, 20C, 20D, 20E, and 20F. The plurality of connection components 30 includes two connection components 30A and 30B.

[0053] (1st wiring example) First, an example of wiring of the bus bar 42A will be described. The bus bar 42A has a first connection portion 61, a second connection portion 62, and an extension portion 63. When viewed from the Z direction, the first connection portion 61 is located on the +X direction side of the electronic component 10A. The first connection portion 61 is electrically connected to, for example, a positive electrode terminal of the electronic component 10A via a connection part 20A. The second connection portion 62 is located on the −X direction side of the electronic component 10A when viewed from the Z direction. The second connection portion 62 is electrically connected to another subunit SU via a coupling bus bar 75.

[0054] By being accommodated in accommodation portion 55, extension portion 63 passes through region R that overlaps with electronic component 10A when viewed from the Z direction, and extends to both sides of region R. For example, extension portion 63 extends linearly in the X direction. Extension portion 63 extends through region R that overlaps with electronic component 10A when viewed from the Z direction, so as to span both the +X direction side and the −X direction side of region R. Bus bar 42A is, for example, a bus bar included in positive electrode line PL of electrical connection unit 1.

[0055] (Second wiring example) Next, an example of wiring of the bus bar 42B will be described. The busbar 42B has a first connection portion 61, a second connection portion 62, an extension portion 63, and an extension portion 64. The first connection portion 61 is electrically connected to, for example, the negative terminal of the electronic component 10A via a connection part 20B that is different from the first connection part 20. The second connection portion 62 is electrically connected to an external connection busbar 76 via a connection part 30A. The extension portion 64 extends to a region R that overlaps with the electronic component 10A when viewed from the Z direction. The extension portion 64 has an end 42e1 of the busbar 42 at a position that overlaps with the region R when viewed from the Z direction. Note that, like the extension portion 63 of the busbar 42A, the extension portion 63 of the busbar 42B may extend through the region R that overlaps with the electronic component 10A when viewed from the Z direction, extending to both sides of the region R. The busbar 42B is, for example, a busbar included in a positive line PL of the electrical connection unit 1.

[0056] (3rd wiring example) Next, an example of wiring of the bus bar 42C will be described. The busbar 42C has a first connection portion 61, a second connection portion 62, an extension portion 63, and an extension portion 64. The first connection portion 61 is electrically connected to, for example, the negative electrode terminal of the electronic component 10B via the connection part 20C. The second connection portion 62 is electrically connected to another subunit SU via a coupling busbar 75. The extension portion 64 extends to a region R that overlaps with the electronic component 10B when viewed from the Z direction. The extension portion 64 has an end 42e1 of the busbar 42 at a position that overlaps with the region R when viewed from the Z direction. The busbar 42C is, for example, a busbar included in the negative electrode line NL of the electrical connection unit 1.

[0057] (4th wiring example) Next, an example of wiring of the bus bar 42D will be described. The bus bar 42D has a first connection portion 61, a second connection portion 62, and an extension portion 63. The first connection portion 61 is electrically connected to, for example, a positive terminal of the electronic component 10B via a connection part 20D. The second connection portion 62 is electrically connected to, for example, a negative terminal of the electronic component 10C via a connection part 20E. The bus bar 42D is, for example, a bus bar included in the negative line NL of the electrical connection unit 1.

[0058] (5th wiring example) Next, an example of wiring of the bus bar 42E will be described. The bus bar 42E has a first connection portion 61, a second connection portion 62, and an extension portion 63. The first connection portion 61 is electrically connected to, for example, the negative electrode terminal of the electronic component 10C via a connection part 20F. The second connection portion 62 is electrically connected to an external connection bus bar 76 via a connection part 30B. The bus bar 42E is, for example, a bus bar included in the negative electrode line NL of the electrical connection unit 1.

[0059] (Fastening member 43) Next, returning to FIG. 6, the fastening member 43 will be described. The fastening member 43 is a component for fastening the bus bar 42 to a component to which the bus bar 42 is connected (connection component 20, connection component 30, or coupling bus bar 75). The fastening member 43 is, for example, a crimp bolt fixed to the bus bar 42. The fastening member 43 penetrates the bus bar 42 in the Z direction. The fastening member 43 is electrically and physically connected to the bus bar 42 while protruding in the +Z direction relative to the bus bar 42. Note that the fastening member 43 is not limited to being fixed by crimping, and may be fixed to the bus bar 42 by welding or other methods.

[0060] The connection component 20 is first fixed to the electronic component 10 by the fastening member 71 or the fastening member 72, and then fixed to the fastening member 43. For example, the fastening member 43 penetrates a first end of the connection component 20. As shown in FIG. 3 , an engaging member 44 (e.g., a nut) is attached to a portion of the fastening member 43 that protrudes in the +Z direction relative to the connection component 20. This attachment mounts the connection component 20 to the wiring board 40. Note that in this disclosure, "an electronic component is mounted on a board" is not limited to a case where the electronic component is directly connected to the board, but also includes a case where the electronic component is connected to the board via another component (e.g., the connection component 20). Also, in this disclosure, "an electronic component is mounted on a board" means that at least the electronic component is electrically connected to the board, and also includes a case where the electronic component is fixed to a member (e.g., a metal plate 80) different from the board instead of or in addition to the board.

[0061] (Heat conduction part 45) As shown in FIGS. 5 and 6 , the heat conductive portion 45 is a member for dissipating and / or storing heat from the base plate 41 by heat transfer from the base plate 41. The heat conductive portion 45 is held on the flat portion 51 while being electrically insulated from the bus bar 42. In the present embodiment, the heat conductive portion 45 is adjacent to the bus bar 42 while ensuring electrical insulation between the heat conductive portion 45 and the bus bar 42. The heat conductive portion 45 is made of a material having better thermal conductivity than the base plate 41. In the present embodiment, the heat conductive portion 45 is made of metal (for example, copper or a copper alloy) like the bus bar 42. The heat conductive portion 45 may overlap the electronic component 10 when viewed from the Z direction, as long as the heat conductive portion 45 is electrically insulated from the electronic component 10.

[0062] The heat conductive portion 45 is formed in a plate shape extending in the horizontal direction. At least a portion of the heat conductive portion 45 extends along the flat portion 51 while being accommodated in the accommodation portion 56. At least a portion of each heat conductive portion 45 extends along the first surface 51a of the flat portion 51. At least a portion of each heat conductive portion 45 extends horizontally within the accommodation portion 56. In the present embodiment, each heat conductive portion 45 extends along the flat portion 51 while being accommodated in the accommodation portion 56 over the entire heat conductive portion 45. However, it is sufficient that at least a portion of the heat conductive portion 45 is accommodated within the accommodation portion 56. The heat conductive portion 45 may extend horizontally along the extension direction of the bus bar 42 or in a direction intersecting the extension direction of the bus bar 42. The heat conductive portion 45 may be formed in a block shape. In the present disclosure, the term "block shape" refers to a shape in which the dimensions in the X and Y directions are equal to the dimension in the Z direction.

[0063] The heat conducting portion 45 is disposed on the same plane as the bus bar 42. That is, at least a portion of the heat conducting portion 45 is disposed within the dimensional range of the bus bar 42 in the Z direction. However, the heat conducting portion 45 and the bus bar 42 may be disposed at positions shifted from each other in the Z direction. The width of the heat conducting portion 45 (the dimension in the direction perpendicular to the extension direction) is narrower than the width of the bus bar 42. However, the width of the heat conducting portion 45 may be wider than the width of the bus bar 42.

[0064] The heat conducting portion 45 includes, for example, heat conducting portions 45A, 45B, 45C, and 45D. The heat conducting portions 45A, 45B, 45C, and 45D are arranged at intervals in the horizontal direction. The heat conductive portion 45A is accommodated in the accommodation portion 56A. The heat conductive portion 45A extends linearly in the X direction along the extension portion 63 on the +Y direction side of the bus bar 42A. In the illustrated example, the heat conductive portion 45A overlaps with at least a portion of the first connection portion 61 and the second connection portion 62 when viewed from the X direction.

[0065] Heat conductive portion 45B is accommodated in accommodation portion 56B. Heat conductive portion 45B extends linearly in the X direction in a portion of planar portion 51 that is located between bus bar 42B and bus bar 42C. In the illustrated example, the width of heat conductive portion 45B is wider than the width of heat conductive portion 45A. Heat conduction portion 45C is accommodated in accommodation portion 56C. Heat conduction portion 45C extends linearly in the X direction in a portion of flat portion 51 that is located between bus bar 42D and bus bar 42E. Heat conductive portion 45D extends linearly in the X direction on the +Y direction side of bus bar 42D. That is, heat conductive portion 45A is provided on the outermost periphery of flat portion 51 on the +Y direction side. In this case, heat conductive portion 45A may be exposed on the outer periphery of flat portion 51. Note that heat conductive portion 45 can be installed at any position on base plate 41 as long as it is electrically insulated from bus bar 42.

[0066] <4. Connection structure> Next, the connection structure of the subunits SU will be described. 2, the first subunit SUX, the second subunit SUY, and the third subunit SUZ are arranged in order from the +X direction side to the -X direction side. The first subunit SUX and the second subunit SUY are electrically connected via a connecting bus bar 75A. The second subunit SUY and the third subunit SUZ are electrically and physically connected via a connecting bus bar 75B.

[0067] Adjacent subunits SU are arranged with their ends facing each other in the X direction overlapping in the Z direction. Specifically, the fixed portion 52 (horizontal plate portion 52b) located on the -X direction side of the first subunit SUX is overlapped from the +Z direction by the fixed portion 52 (horizontal plate portion 52b) located on the +X direction side of the second subunit SUY. The fixed portion 52 (horizontal plate portion 52b) located on the +X direction side of the third subunit SUX is overlapped from the +Z direction by the fixed portion 52 (horizontal plate portion 52b) located on the -X direction side of the second subunit SUY.

[0068] <5. Metal Plate 80, Insulating Sheet 91, Heat Transfer Member 92, and Insulating Cover 93> Next, the metal plate 80, the insulating sheet 91, the heat transfer member 92, and the insulating cover 93 will be described.

[0069] <5.1 Metal Plate 80> FIG. 9 is a perspective view showing the electrical connection unit 1 in a partially exploded state. As shown in Fig. 9, the metal plate 80 is a member that ensures the rigidity of the electrical connection unit 1 and also enhances the heat dissipation of the electrical connection unit 1. The metal plate 80 is made of metal (for example, aluminum or an aluminum alloy). The metal plate 80 is an example of a "heat dissipation plate." The heat dissipation plate is not limited to metal, and various materials can be used as long as they have superior thermal conductivity compared to the base plate 41, for example.

[0070] When viewed from the Z direction, the metal plate 80 has a rectangular shape extending along the X direction. The metal plate 80 has a first end 80e1, a second end 80e2, a third end 80e3, and a fourth end 80e4. The first end 80e1 and the second end 80e2 are a pair of longitudinal ends of the metal plate 80 and are spaced apart in the X direction. The third end 80e3 and the fourth end 80e4 are a pair of lateral ends of the metal plate 80 and are spaced apart in the Y direction. In this embodiment, the metal plate 80 is large enough to cover the entire three subunits SU (main body portions MU) from below. Specifically, the length of the metal plate 80 in the X direction is greater than the length of the main body portion MU in the X direction. The length of the metal plate 80 in the Y direction is greater than the length of the main body portion MU in the Y direction. Therefore, when viewed from the Z direction, the area of ​​the metal plate 80 is greater than the area of ​​the main body portion MU.

[0071] The metal plate 80 includes, for example, a flat portion 81, a plurality of fixing portions 82, a plurality of fixing portions 83, and a peripheral wall portion 84.

[0072] The flat surface portion 81 is a plate-shaped portion of the metal plate 80. The flat surface portion 81 is a plate-shaped portion that extends horizontally. The flat surface portion 81 forms the main portion of the metal plate 80. The flat surface portion 81 forms the base (metal base) of the metal plate 80. In this embodiment, the flat surface portion 81 is large enough to cover the entire three subunits SU (main body portions MU) from below. The flat surface portion 81 faces the wiring board 40 for the three subunits SU. In this embodiment, the metal plate 80 faces the second surface 51b of each subunit SU with a gap S1 (see FIG. 7) between the metal plate 80 and the flat surface portion 51 (second surface 51b) of each subunit SU.

[0073] 7 and 9, the fixing portion 82 is a portion for fixing the base plate 41 of each subunit SU to the metal plate 80. When viewed from the Z direction, the fixing portion 82 is provided at a position corresponding to the fixing portion 52 of each subunit SU. The fixing portion 82 is a cylindrical or prismatic boss that protrudes from the flat portion 81 of the metal plate 80 in the +Z direction.

[0074] The fixing portion 83 is a portion for fixing the electronic component 10 of each subunit SU directly to the metal plate 80 without using the base plate 41. When viewed from the Z direction, the fixing portion 83 is provided at a position corresponding to the mounting portion 14 of the electronic component 10 of each subunit SU. The fixing portion 83 is a cylindrical or prismatic boss that protrudes in the +Z direction from the flat portion 81. The amount of protrusion of the fixing portion 83 in the Z direction is smaller than the amount of protrusion of the fixing portion 82 in the Z direction.

[0075] 2, the peripheral wall portion 84 extends in the +Z direction from the outer peripheral edge of the flat portion 81. The peripheral wall portion 84 extends around the entire periphery of the flat portion 81. The length of the peripheral wall portion 84 in the Z direction is shorter than the length of the fixing portions 82, 83 in the Z direction.

[0076] <5.2 Insulation sheet 91> The insulating sheet 91 is an insulating member for electrically insulating the metal plate 80 from the bus bars 42 of each subunit SU. The insulating sheet 91 is made of a synthetic resin such as polyester or polyimide, and has insulating properties. The insulating sheet 91 has a rectangular shape when viewed from the Z direction. The insulating sheet 91 is provided so as to cover the entire flat portion 81 of the metal plate 80 from the +Z direction side. Therefore, the main body portion MU faces the metal plate 80 with the insulating sheet 91 sandwiched therebetween.

[0077] The insulating sheet 91 is attached to the flat portion 81 of the metal plate 80. The insulating sheet 91 has cutouts or openings formed therein to avoid the fixing portions 82 and 83 of the metal plate 80. In this embodiment, the thickness of the insulating sheet 91 in the Z direction is thinner than the thickness of the peripheral wall portion 84 in the Z direction. Therefore, the insulating sheet 91 is positioned horizontally relative to the metal plate 80 by being surrounded by the peripheral wall portion 84.

[0078] <5.3 Heat Transfer Material 92> 9, the heat transfer member 92 is a member for transferring heat generated by the electronic component 10 when current is applied and / or heat generated by the bus bar 42 itself when current is applied to the metal plate 80. The heat transfer member 92 is, for example, an elastic heat transfer sheet (for example, a thermally conductive silicone sheet). However, the heat transfer member 92 is not limited to the above example, and may be a heat transfer member formed of a thermally conductive gel or other materials.

[0079] The multiple heat transfer members 92 include, for example, one or more (e.g., multiple) heat transfer members 92 corresponding to the first subunit SUX, one or more (e.g., multiple) heat transfer members 92 corresponding to the second subunit SUY, and one or more (e.g., multiple) heat transfer members 92 corresponding to the third subunit SUZ. The heat transfer member 92 corresponding to the first subunit SUX is arranged at a position overlapping the first subunit SUX when viewed from the Z direction, and transfers heat generated by the first subunit SUX to the metal plate 80. The heat transfer member 92 corresponding to the second subunit SUY is arranged at a position overlapping the second subunit SUY when viewed from the Z direction, and transfers heat generated by the second subunit SUX to the metal plate 80. The heat transfer member 92 corresponding to the third subunit SUZ is arranged at a position overlapping the third subunit SUZ when viewed from the Z direction, and transfers heat generated by the third subunit SUZ to the metal plate 80.

[0080] FIG. 10 is a bottom view showing the wiring board 40. As shown in FIG. 10 , the heat transfer members 92 transfer heat transferred from the electronic component 10 to the bus bar 42 and / or heat generated in the bus bar 42 from the bus bar 42 to the metal plate 80. The heat transfer members 92 are provided partially on the wiring board 40 in the horizontal direction. For example, the heat transfer members 92 are arranged in positions on the wiring board 40 that overlap with portions of the bus bar 42 when viewed from the Z direction. The heat transfer members 92 are arranged in positions that overlap with portions of the bus bar 42 near the electronic component 10 (e.g., electronic components 10A and 10B) when viewed from the Z direction. In this embodiment, the heat transfer members 92 are arranged in positions that overlap with the connecting part 20 (the connection portion between the bus bar 42 and the electronic component 10) when viewed from the Z direction.

[0081] FIG. 11 is a cross-sectional view of the structure shown in FIG. 8 taken along line F11-F11. 11 , the heat transfer member 92 is disposed in a crushed state between the main body MU and the insulating sheet 91 in the Z direction. A portion of the heat transfer member 92 located on the −Z direction side is in contact with the metal plate 80 via the insulating sheet 91. The heat transfer member 92 may be disposed between the insulating sheet 91 and the metal plate 80.

[0082] A portion of the heat transfer member 92 located on the +Z direction side is in contact with the bus bar 42. In the present embodiment, the heat transfer member 92 is in contact with the bus bar 42 at a position overlapping with the connection part 20 when viewed from the Z direction. In this case, the heat transfer member 92 facilitates the transfer of heat from the electronic component 10 to the connection part 20 from the connection part 20 to the metal plate 80 via the bus bar 42. A portion of the heat transfer member 92 is disposed in a position overlapping with the fastening member 43 when viewed from the Z direction, and is in contact with the fastening member 43. In this case, the heat transfer member 92 facilitates the transfer of heat from the electronic component 10 to the connection part 20 from the fastening member 43 to the metal plate 80.

[0083] In this embodiment, a portion of the heat transfer member 92 contacts the bus bar 42 at a position that overlaps the electronic component 10 when viewed from the Z direction. In this case, the heat transfer member 92 makes it easier to transfer heat transferred from the electronic component 10 to the bus bar 42, from the bus bar 42 to the metal plate 80. In the example shown in FIG. 11 , the upper surface of the bus bar 42 contacts the electronic component 10, so that the bus bar 42 is thermally connected to the electronic component 10. Note that the portion of the bus bar 42 that is thermally connected to the electronic component 10 may be the extension portion 63 or the extension portion 64.

[0084] <5.4 Insulation cover 93> Returning to FIG. 1, the insulating cover 93 will be described. The insulating cover 93 is a member for ensuring the safety of the electrical paths of the main body unit MU. The insulating cover 93 is made of, for example, synthetic resin and has insulating properties. The insulating cover 93 is, for example, box-shaped with an open -Z side. The insulating cover 93 is attached to the metal plate 80 so as to cover the main body unit MU from the +Z side. In this embodiment, a plurality of ventilation holes 93h are formed in the top wall of the insulating cover 93. Note that the insulating cover 93 is not limited to a box-shaped member, and may be a sheet-shaped member that covers the electrical paths of the main body unit MU.

[0085] <6. Fixed structure> Next, the anchoring structure of the subunit SU will be described. 7, the main body MU is stacked in the Z direction on the metal plate 80 with the fixing portions 52 of adjacent subunits SU overlapping with the fixing portions 82 of the metal plate 80. The fixing portions 52, 82 overlapping in the Z direction are fixed to each other by fastening members 111 (e.g., screws or bolts). The fastening members 111 pass through the fixing portions 52 of the subunits SU and are then fastened to the fixing portions 82 of the metal plate 80.

[0086] With the main body portion MU and the metal plate 80 stacked together, the fixing portion 83 of the metal plate 80 passes through the through hole 51h of the subunit SU. The mounting portion 14 of the electronic component 10 is overlapped in the Z direction on the fixing portion 83. The mounting portion 14 and the fixing portion 83 that overlap in the Z direction are fixed to each other by a fastening member 112 (e.g., a screw or a bolt). The fastening member 112 passes through the mounting portion 14 and is then fastened to the fixing portion 83 of the metal plate 80. A gap is provided between the inner circumferential surface of the through hole 51h and the fixing portion 83 to allow air to pass through.

[0087] 7. Heat Transfer 11 , the subunit SU generates heat, for example, when current is applied to the electronic component 10 or the bus bar 42. Of the heat generated in the subunit SU, part of the heat from the base plate 41 is transferred to the metal plate 80 (flat portion 81) via the heat transfer member 92 and the insulating sheet 91. Part of the heat from the base plate 41 is transferred to the fixing portion 82 of the metal plate 80 via the fixing portion 52. Part of the heat from the electronic component 10 is transferred to the fixing portion 83 of the metal plate 80 via the mounting portion 14. In this way, the heat generated in the subunit SU is transferred to the metal plate 80 and then released from the metal plate 80 to the outside.

[0088] Here, a portion of the heat transferred to the base plate 41 is transferred to the heat conductive portion 45. The heat transferred to the heat conductive portion 45 is released to the outside from the heat conductive portion 45. In this manner, in this embodiment, the heat transferred to the base plate 41 is transferred to the bus bar 42 and the heat conductive portion 45, and is thereby easily diffused throughout the wiring board 40. The heat diffused in the wiring board 40 is directly released to the outside, or indirectly released to the outside via the heat transfer member 92 or the metal plate 80.

[0089] The electrical connection unit 1 of this embodiment includes a base plate 41 having a flat portion 51 and a storage portion 56 formed therein that penetrates the flat portion 51 in the Z direction, a bus bar 42 held on the flat portion 51, an electronic component 10 facing the base plate 41 and electrically connected to the bus bar 42, and a heat conductive portion 45 that is electrically isolated from the bus bar 42 and the electronic component 10, is held on the base plate 41 while being stored in the storage portion 56, and has better thermal conductivity than the base plate 41. According to this configuration, heat transferred from current-carrying parts such as the bus bar 42 and the electronic component 10 to the base plate 41 can be effectively dissipated and / or stored in the heat conductive portion 45. This configuration improves the heat dissipation performance of the electrical connection unit 1. Furthermore, by accommodating the heat conductive portion 45 in the accommodating portion 56, the electrical connection unit 1 can be made lower in height (thinner) than when the heat conductive portion 45 is provided separately from the base plate 41, for example, on the first surface 51a or the second surface 51b of the flat portion 51. Furthermore, by accommodating the heat conductive portion 45 in the accommodating portion 56, the base plate 41 and the heat conductive portion 45 can be easily handled as a single unit. This configuration improves the ease of handling during the manufacture of the electrical connection unit 1.

[0090] In the electrical connection unit 1 of this embodiment, the heat conductive portion 45 extends in a direction intersecting the Z direction. This configuration allows the heat transferred to the heat conducting portion 45 to be diffused in the horizontal direction, thereby improving the heat dissipation performance.

[0091] In the electrical connection unit 1 of this embodiment, the bus bar 42 is held by the base plate 41 in a state where it is housed in the housing portion 55 . According to this configuration, by accommodating the bus bar 42 in the accommodating portion 55, the electrical connection unit 1 can be made lower in height (thinner) than when the bus bar 42 is provided separately from the base plate 41, for example, on the first surface 51a or the second surface 51b of the flat portion 51. Furthermore, by accommodating the bus bar 42 in the accommodating portion 55, the base plate 41 and the bus bar 42 can be easily handled as a unit. This configuration improves the ease of handling during the manufacture of the electrical connection unit 1.

[0092] In the electrical connection unit 1 of this embodiment, the bus bar 42 and the heat conductive portion 45 are insert-molded into the base plate 41. This configuration can eliminate or reduce the work of manually attaching the bus bar 42 and the heat conductive portion 45 to the base plate 41. This configuration can further improve the ease of assembly of the electrical connection unit 1.

[0093] In the electrical connection unit 1 of this embodiment, at least a portion of the heat conducting portion 45 is exposed to the outside of the base plate 41 through the opening of the accommodation portion 56. This configuration allows the heat transferred to the heat conducting portion 45 to be easily released to the outside. This configuration can improve the heat dissipation performance.

[0094] 7. Second Embodiment FIG. 12 is a cross-sectional view corresponding to FIG. 11 according to the second embodiment. In the first embodiment described above, the heat transfer member 92 is arranged at a position overlapping the bus bar 42 when viewed from the Z direction. However, as shown in Fig. 12 , the heat transfer member 200 may be arranged at a position overlapping the heat conduction portion 45 when viewed from the Z direction. In this case, the heat transfer member 200 may overlap the entire heat conduction portion 45, or may overlap only a portion of the heat conduction portion 45.

[0095] According to this embodiment, the heat transferred to the heat conducting portion 45 is efficiently transferred to the metal plate 80 via the heat conducting member 200. This further improves the heat dissipation performance. The heat conducting member 200 can be made of the same material as the heat conducting member 92 connected to the bus bar 42. However, since the heat conducting portion 45 does not function as a current-carrying portion, the heat conducting member 200 may be made of an electrically conductive material. The heat conducting members 92 and 200 may also be integrally formed.

[0096] 8. Third Embodiment Fig. 13 is a bottom view of the wiring board 40 according to the third embodiment. Fig. 14 is a cross-sectional view corresponding to F14-F14 in Fig. 13. This embodiment differs from the above-described embodiments in that the base plate 41 has a two-layer structure. 13 and 14, the base plate 300 includes a first plate 301, an insulating sheet 302, and a second plate 303. The first plate, the insulating sheet 302, and the second plate 303 are stacked in this order from the +Z direction side to the −Z direction side. The first plate 301, the insulating sheet 302, and the second plate 303 are formed to have the same outer shape as one another when viewed from the Z direction. That is, the base plate 300 (flat portion 51 and fixed portion 52) is configured by stacking the first plate 301, the insulating sheet 302, and the second plate 303, respectively. However, at least the portion of the base plate 300 located on the flat portion 51 may be formed by the first plate 301, the insulating sheet 302, and the second plate 303.

[0097] First plate 301 is a plate that holds busbars 42. First plate 301 and busbars 42 are integrated by insert molding. A plurality of accommodating portions 55 are formed in a portion of first plate 301 that forms flat portion 51. Each accommodating portion 55 penetrates first plate 301 in the Z direction. A busbar 42 is accommodated in each accommodating portion 55.

[0098] The insulating sheet 302 provides electrical insulation between the first plate 301 and the second plate 303. The insulating sheet 302 is interposed between the first plate 301 and the second plate 303. The insulating sheet 302 is fixed, for example, by adhesive to the surface of the first plate 301 facing the -Z direction and the surface of the second plate 303 facing the +Z direction. The insulating sheet 302 is made of a synthetic resin such as polyester or polyimide and has insulating properties. The insulating sheet 302 covers the opening of the housing portion 55 on the -Z direction side, thereby covering the bus bar 42 from the -Z direction side.

[0099] The second plate 303 is a plate that holds the heat conductive portion 45. The second plate 303 is fixed to the insulating sheet 302 by adhesive or the like. The second plate 303 and the heat conductive portion 45 are integrated by insert molding. A plurality of accommodating portions 310 are formed in the portion of the second plate 303 that forms the flat portion 51. Each accommodating portion 310 penetrates the second plate 303 in the Z direction. A heat conductive portion 45 is accommodated in each accommodating portion 310. The heat conductive portion 45 is, for example, heat conductive portions 45A and 45B.

[0100] 13, the heat conductive portion 45A is provided on the second plate 303 at a position overlapping both of the first connection portions 61 of the bus bars 42A and 42B when viewed from the Z direction. In this embodiment, the heat conductive portion 45A is formed in a rectangular shape with its longitudinal direction being a direction (Y direction) that intersects with the extension direction (X direction) of the first connection portions 61 of the bus bars 42A and 42B when viewed from the Z direction. The heat conductive portion 45A is provided so as to straddle the first connection portions 61 of the bus bars 42A and 42B when viewed from the Z direction.

[0101] The heat conductive portion 45A is exposed through the accommodation portion 310 on both surfaces of the second plate 303 facing the Z direction. The surface of the heat conductive portion 45A facing the +Z direction faces the bus bars 42A and 42B in the Z direction via the insulating sheet 302. The heat conductive portion 45A and the bus bars 42A and 42B are electrically insulated from each other via the insulating sheet 302. The surface of the heat conductive portion 45A facing the -Z direction faces the metal plate 80 in the Z direction via the heat transfer member 92. The heat conductive portion 45A is thermally connected to the metal plate 80 via the heat transfer member 92.

[0102] The heat conductive portion 45B is provided on the second plate 303 at a position overlapping both of the first connection portions 61 of the bus bars 42C, 42D as viewed from the Z direction. In this embodiment, the heat conductive portion 45B is formed in a rectangular shape with its longitudinal direction being a direction (Y direction) that intersects with the extension direction (X direction) of the first connection portions 61 of the bus bars 42C, 42D as viewed from the Z direction. The heat conductive portion 45B is provided so as to straddle the first connection portions 61 of the bus bars 42C, 42D as viewed from the Z direction.

[0103] Similar to heat conduction unit 45A, heat conduction unit 45B is exposed through accommodation unit 310 on both surfaces of second plate 303 facing the Z direction. In this case, the surface of heat conduction unit 45B facing the +Z direction faces bus bars 42C and 42D in the Z direction via insulating sheet 302. Heat conduction unit 45B and bus bars 42C and 42D are electrically insulated from each other via insulating sheet 302. The surface of heat conduction unit 45B facing the -Z direction faces metal plate 80 in the Z direction via heat transfer member 92. Heat conduction unit 45B is thermally connected to metal plate 80 via heat transfer member 92.

[0104] According to this embodiment, base plate 300 has a laminated structure of first plate 301 that holds bus bar 42 and second plate 303 that holds heat conductive portion 45, so bus bar 42 and heat conductive portion 45 are arranged with a deviation in the Z direction. This configuration allows bus bar 42 and heat conductive portion 45 to be arranged overlapping each other when viewed in the Z direction, improving the layout flexibility of bus bar 42 and heat conductive portion 45.

[0105] In this embodiment, when viewed from the Z direction, the bus bar 42 and the heat conducting portion 45 at least partially overlap with each other, thereby enabling efficient heat transfer between the bus bar 42 and the heat conducting portion 45.

[0106] In this embodiment, the bus bar 42 (first connection portion 61) and the heat conduction portion 45 extend in directions that intersect with each other when viewed from the Z direction, which improves the degree of freedom of the heat transfer path.

[0107] In the third embodiment described above, the bus bar 42 and the heat conductive portion 45 are configured such that at least a portion of them overlap when viewed from the Z direction, but the present invention is not limited to this configuration. For example, as shown in Fig. 15 , the bus bar 42 and the heat conductive portion 45 may be disposed at positions that are shifted horizontally when viewed from the Z direction. In the third embodiment described above, a configuration in which the insulating sheet 302 is interposed between the first plate 301 and the second plate 303 has been described. However, as long as insulation is achieved between the bus bar 42 and the heat conductive portion 45, the insulating sheet 302 is not an essential component, as shown in FIG. 16 . Insulation between the bus bar 42 and the heat conductive portion 45 can be achieved, for example, by forming a recess in at least one of the accommodation portions 55, 310 that does not penetrate the plates 301, 303. Alternatively, insulation between the bus bar 42 and the heat conductive portion 45 can be achieved by arranging the bus bar 42 and the heat conductive portion 45 at positions that are offset horizontally when viewed from the Z direction.

[0108] <9. Other Modifications> Next, several modified examples will be described. Note that the configuration of each modified example is the same as that of the above embodiment except for the configuration described below.

[0109] (First Modification) The wiring board 40 is not limited to a structure in which the base plate 41 and the bus bar 42 are integrated by insert molding. For example, the base plate 41 may be molded with a housing portion 55 for housing the bus bar 42, and then the bus bar 42 may be placed in the housing portion 55. In this case, the bus bar 42 may be fixed to the housing portion 55 by fitting, or may be fixed to the housing portion 55 by adhesive or other fixing means. In these cases, potting may be applied to fill the gap between the bus bar 42 and the housing portion 55.

[0110] (Second Modification) The base member of the wiring board 40 is not limited to the base plate 41 having the plate-shaped flat portion 51. The wiring board 40 may be a base member (for example, an insulating sheet) having a sheet-shaped flat portion 51. In this case, the accommodation portion 55 may be formed by a portion of the flat portion 51 conforming to the outer shape of the bus bar 42. In this disclosure, the term "sheet-shaped" or "sheet" is not limited to a member having a thickness of 1 mm or more, and may also refer to a member having a thickness of less than 1 mm (so-called film).

[0111] (Third Modification) The base plate 41 of the wiring board 40 may include a plurality of members (plate members or sheet members). The plurality of members are arranged to sandwich the plurality of bus bars 42 arranged horizontally, for example, from both sides in the Z direction. For example, the plurality of members are integrated by sandwiching the plurality of bus bars 42, for example, by lamination molding. The plurality of members form a planar portion 51. In this case, the accommodating portion 55 may be formed hollow inside the base plate 41 (between the plurality of members). The plurality of members may be a plurality of plate members, a plurality of sheet members, or a combination of plate members and sheet members. The sheet member may be, for example, a flexible sheet member. The planar portion 51 formed by the plurality of members has openings that expose at least the first connection portion 61 and the second connection portion 62 of the bus bars 42. For example, in this case, the accommodating portion 55 formed between the plurality of members corresponds to an example of an "accommodating portion recessed in the first direction (Z direction)."

[0112] (Fourth Modification) The connection between the electronic component 10 and the bus bar 42 is not limited to the connection via the connection component 20. The electronic component 10 may be directly connected to the bus bar 42 using a fastening member (for example, a bolt or a screw), welding, or the like.

[0113] Several embodiments and modifications have been described above. However, the embodiments and modifications are not limited to the above examples. For example, multiple embodiments may be realized in combination with each other. The present invention is not limited by the above description, but is limited only by the scope of the accompanying claims. In the above embodiment, the electrical connection unit 1 for a vehicle has been described, but the present invention is not limited to this configuration. In the above-described embodiment, a configuration in which the main body unit MU uses the metal plate 80 as part of the housing has been described, but this configuration is not limited thereto. The housing of the main body unit MU may be made of a resin material or the like. Even in this case, by using the heat conductive portion 45 having heat dissipation / heat storage functions in the base plate 41 as in this embodiment, heat can be more easily diffused throughout the base plate 41, and heat buildup in the electrical connection unit 1 can be prevented.

[0114] In the above-described embodiment, the wiring board 40 and the busbars 42 are integrally formed, but the present invention is not limited to this configuration. The busbars 42 may be formed separately from the wiring board 40. In the above-described embodiment, the bus bar 42 and the heat conductive portion 45 are formed from the same material, but the present invention is not limited to this configuration. The bus bar 42 and the heat conductive portion 45 may be formed from different materials. In the above-described embodiment, the busbar 42 and the heat conductive portion 45 are configured to be flush with the base plate, but the present invention is not limited to this configuration. The busbar 42 and the heat conductive portion 45 may protrude in the Z direction from the base plate while being accommodated in the corresponding accommodation portion.

[0115] In the above-described embodiment, the entire surface of the heat conductive portion 45 is exposed to the outside of the base plate through the housing portion, but the present invention is not limited to this configuration. It is sufficient that at least a portion of the heat conductive portion 45 is exposed to the outside of the base plate. In the above-described embodiment, an example in which the main body MU is configured by a plurality of subunits SUX, SUY, and SUZ has been described, but this configuration is not limiting. The electrical connection unit 1 may also be configured by a single circuit structure. In the above-described embodiment, the heat conducting portion 45 is connected to the metal plate 80 via a heat transfer member, but the present invention is not limited to this configuration. The heat conducting portion 45 may be directly connected to the metal plate 80. In the above-described embodiment, a configuration in which a plurality of bus bars 42 and a plurality of heat conductive portions 45 are provided has been described, but the present invention is not limited to this configuration. A single bus bar 42 and a single heat conductive portion 45 may also be provided.

[0116] In addition, the components in the above-described embodiments can be replaced with well-known components as appropriate, without departing from the spirit of the present invention. [Explanation of symbols]

[0117] 1: Electrical connection unit 10, 10A, 10B, 10C, 10X, 10Y, 10Z: Electronic components 41: Base plate (base member) 42, 42A, 42B, 42C, 42D, 42E: Busbar 45, 45A, 45B, 45C, 45D: Heat conduction section 51: Flat part 55, 55A, 55B, 55C, 55D, 55E: Storage section (second storage section) 56, 56A, 56B, 56C, 56D: Storage section (first storage section) 80: Metal plate (heat dissipation plate) 92,200: Heat transfer material 300: Base plate (base material) 301: First Plate 303: Second Plate 310: Storage unit

Claims

1. a base member having a plate-like or sheet-like planar portion, the planar portion having a first housing portion formed thereon that is recessed in a thickness direction of the planar portion or that penetrates through the thickness direction; a bus bar held by the planar portion; an electronic component facing the base member and electrically connected to the bus bar; an electrical connection unit comprising: a heat conductive portion that is electrically isolated from the bus bar and the electronic component, is held by the base member while being accommodated in the first accommodating portion, and has better thermal conductivity than the base member.

2. 2. The electrical connection unit according to claim 1, wherein the heat conducting portion extends in a direction intersecting the thickness direction.

3. a second housing portion recessed in the thickness direction or penetrating through the thickness direction is formed at a position of the planar portion away from the first housing portion, 3. The electrical connection unit according to claim 1, wherein the bus bar is held by the base member while being housed in the second housing portion.

4. 3. The electrical connection unit according to claim 1, wherein the bus bar and the heat conductive portion are insert-molded into the base member.

5. 3. The electrical connection unit according to claim 1, wherein at least a portion of the heat conducting portion is exposed to the outside of the base member through an opening in the first housing portion.

6. a heat dissipation plate provided so as to overlap the base member and thermally connected to the base member; a heat transfer member provided between the heat dissipation plate and the base member, 3. The electrical connection unit according to claim 1, wherein the heat transfer member is provided at a position overlapping the heat conducting portion when viewed in the thickness direction.

7. The base member is a first plate in which the first accommodation portion is formed and in which the heat conduction portion is held; 3. The electrical connection unit according to claim 1, further comprising: a second plate that is stacked on the first plate in the thickness direction and that holds the bus bars.

8. The electrical connection unit according to claim 7 , wherein the heat conducting portion is provided at a position overlapping at least a portion of the bus bar when viewed in the thickness direction.

9. The electrical connection unit according to claim 7 , wherein the bus bar and the heat conductive portion extend in directions that intersect with each other when viewed in the thickness direction.

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