Electrical connection unit

Abstract

One embodiment provides an electrical connection unit that can improve heat dissipation. [Solution] An electrical connection unit according to one embodiment includes a first electronic component, a component to be connected, a third electronic component, a first busbar, a second busbar, a heat dissipation member, a first heat transfer member, and a second heat transfer member. The first electronic component has a first terminal and a second terminal. The third electronic component generates more heat than the component to be connected. The first busbar electrically connects the first terminal of the first electronic component to the component to be connected. The second busbar electrically connects the second terminal of the first electronic component to the third electronic component. The heat dissipation member faces the first busbar and the second busbar. The first heat transfer member is positioned between the first busbar and the heat dissipation member. The second heat transfer member is positioned between the second busbar and the heat dissipation member and is larger than the first heat transfer member.

Description

Technical Field

[0001] Embodiments of the present invention relate to an electrical connection unit.

Background Art

[0002] An electrical connection unit having an electronic component and a bus bar connected to the electronic component is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, improvement in heat dissipation is expected for the electrical connection unit.

[0005] One embodiment provides an electrical connection unit capable of improving heat dissipation.

Means for Solving the Problems

[0006] An electrical connection unit according to one embodiment includes a first electronic component, a component to be connected, a third electronic component, a first busbar, a second busbar, a heat dissipation member, a first heat transfer member, and a second heat transfer member. The first electronic component has a first terminal and a second terminal. The component to be connected is the second electronic component or a connection component for external connection. The third electronic component generates more heat than the component to be connected. The first busbar electrically connects the first terminal of the first electronic component to the component to be connected. The second busbar electrically connects the second terminal of the first electronic component to the third electronic component. The heat dissipation member faces the first busbar and the second busbar. The first heat transfer member is positioned between the first busbar and the heat dissipation member. The second heat transfer member is positioned between the second busbar and the heat dissipation member and is larger than the first heat transfer member. [Effects of the Invention]

[0007] According to one embodiment, heat dissipation can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] A cross-sectional view showing the electrical connection unit of the first embodiment. [Figure 2] A perspective view illustrating the main body of the first embodiment. [Figure 3] A perspective view illustrating a subunit of the first embodiment. [Figure 4] A perspective view showing a partially disassembled subunit of the first embodiment. [Figure 5] A perspective view illustrating the electronic components and connecting components of the first embodiment. [Figure 6] A perspective view illustrating the electronic components and connecting components of the first embodiment. [Figure 7] A perspective view showing the connecting components of the first embodiment. [Figure 8] A perspective view showing a wiring substrate of the first embodiment. [Figure 9] A perspective view showing a partially disassembled wiring substrate of the first embodiment. [Figure 10] Plan view showing the wiring substrate of the first embodiment. [Figure 11] Perspective view showing a partial decomposition of the electrical connection unit of the first embodiment. [Figure 12] Bottom view showing the wiring substrate of the first embodiment. [Figure 13] Cross-sectional view taken along line F13 - F13 of the structure shown in FIG. 10. [Figure 14] Cross-sectional view showing a modified example of the first embodiment. [Figure 15] [[ID=十六]]Cross-sectional view showing a modified example of the first embodiment. [Figure 16] Cross-sectional view showing a modified example of the first embodiment. [Figure 17] Cross-sectional view showing a modified example of the first embodiment. [Figure 18] Plan view for explaining the size and arrangement of the heat transfer member of the first embodiment. [Figure 19] Bottom view for explaining the size and arrangement of the heat transfer member of the first embodiment. [Figure 20] Cross-sectional view taken along line F20 - F20 of the structure shown in FIG. 10. [Figure 21] Plan view showing the electrical connection unit of the second embodiment. [Figure 22] Cross-sectional view taken along line F22 - F22 of the electrical connection unit shown in FIG. 21.

Mode for Carrying Out the Invention

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

[0010] In the present disclosure, terms are defined as follows. "Connection" is not limited to mechanical connection and may include electrical connection. That is, "connection" is not limited to the case where two elements to be connected are directly connected, and may include the case where two elements to be connected are connected with another element intervening therebetween. "Accommodation" is not limited to the case where the whole of a component is accommodated, and may include the case where only a part of the component is accommodated (with another part of the component protruding). "Facing" means that the virtual projection images of two objects overlap when viewed from a specific direction. That is, "facing" is not limited to the case where two objects directly face each other, and may include the case where two objects face each other with another member existing between them. "Parallel", "orthogonal", or "the same" may include the cases of "substantially parallel", "substantially orthogonal", or "substantially the same", respectively.

[0011] In the present disclosure, the +X direction, -X direction, +Y direction, -Y direction, +Z direction, and -Z direction are defined as follows. The +X direction is the direction from the first end portion 80e1 to the second end portion 80e2 of a metal plate 80 described later (see FIG. 2). The -X direction is the direction opposite to the +X direction. Hereinafter, when the +X direction and the -X direction are not distinguished, they are simply referred to as the "X direction". The +Y direction and the -Y direction are directions that intersect (for example, are orthogonal) to the X direction. The +Y direction is the direction from the third end portion 80e3 to the fourth end portion 80e4 of the metal plate 80 described later (see FIG. 2). The -Y direction is the direction opposite to the +Y direction. Hereinafter, when the +Y direction and the -Y direction are not distinguished, they are simply referred to as the "Y direction". The +Z direction and the -Z direction are directions that intersect (for example, are orthogonal) 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 the +Z direction and the -Z direction are not distinguished, they are simply referred to as the "Z direction". The Z direction is an example of the "first direction".

[0012] In the following, the X and Y directions may be referred to as the "horizontal direction" if they are not distinguished. In the following, the Z direction may be referred to as the "vertical direction." Also, in the following, the +Z direction may be referred to as "up" and the -Z direction as "down." However, these expressions are for the sake of explanation and do not limit the direction of gravity of the electrical connection unit 1 (the installation orientation of the electrical connection unit 1).

[0013] (First Embodiment) <1. Configuration of the electrical connection unit> Figure 1 is a cross-sectional view showing an electrical connection unit 1 according to an embodiment. The electrical connection unit 1 is an in-vehicle device installed in vehicles such as EVs (Electric Vehicles), HEVs (Hybrid Electric Vehicles), or PHEVs (Plug-in Hybrid Electric Vehicles). The electrical connection unit 1 may also be referred to as an "electrical connection box" or "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 Figure 11), a plurality of heat transfer members 92, and an insulating cover 93.

[0015] <2. Main body> First, let me explain the main unit (MU). Figure 2 is a perspective view illustrating the main body MU. The main body MU is the part of the electrical connection unit 1 that performs the main function (e.g., switching of electrical connection states or overcurrent protection). In this embodiment, the main body MU is divided into a plurality of subunits SU. The main body MU is formed by connecting a plurality of subunits SU. In this embodiment, the main body MU has three subunits SU (subunits SUX, SUY, SUZ). Each subunit SU may be referred to as a "circuit configuration".

[0016] Subunit SUX has a first electrical function. 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] Subunit SUY has a second electrical function, which is different from the first function. 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] Subunit SUZ has a third electrical function, which is distinct from the first and second functions. 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, subunit SUX is positioned on the +X side relative to subunit SUY. Subunits SUX and SUY are electrically connected via a plurality of connecting busbars 75 spanning the first wiring substrate 40X and the second wiring substrate 40Y. On the other hand, subunit SUZ is positioned on the -X side relative to subunit SUY. Subunits SUZ and SUY are electrically connected via a plurality of connecting busbars 75 (only one is shown in Figure 2) spanning the third wiring substrate 40Z and the second wiring substrate 40Y. The connecting busbars 75 are positioned on the opposite side of the metal plate 80 relative to the plurality of subunits SU.

[0020] In this embodiment, the three cable routing substrates 40X, 40Y, and 40Z included in the three subunits SUX, SUY, and SUZ are arranged on the same plane. In other words, the three cable routing substrates 40X, 40Y, and 40Z are positioned at the same height in the Z direction. As a result, the three cable routing substrates 40X, 40Y, and 40Z form one large cable routing substrate 40M.

[0021] In this embodiment, the three subunits SUX, SUY, and SUZ have the same or similar basic structure as each other. For this reason, one subunit SU will be described in detail below as a representative example. Hereafter, when subunits SUX, SUY, and SUZ are not distinguished, they will simply be referred to as "subunit SU". Similarly, when electronic components 10X, 10Y, and 10Z are not distinguished, they will simply be referred to as "electronic component 10". Furthermore, when the first wiring substrate 40X, the second wiring substrate 40Y, and the third wiring substrate 40Z are not distinguished, they will simply be referred to as "wiring substrate 40". One subunit SU included in the three subunits SUX, SUY, and SUZ is an example of a "first subunit". On the other hand, another subunit SU included in the three subunits SUX, SUY, and SUZ is an example of a "second subunit".

[0022] Furthermore, the main body MU does not necessarily have to be divided into multiple subunits SU, as in the example described above. That is, the main body MU may be formed from multiple electronic components 10 and one wiring substrate 40. Also, the two or more subunits SU are not limited to subunits SU having different functions, but may also be subunits SU having the same function.

[0023] <3. Subunit Configuration> Next, we will explain the configuration of the subunit SU. Figure 3 is a perspective view illustrating subunit SU. Figure 4 is a perspective view showing subunit SU partially disassembled. Subunit SU includes, for example, a plurality of electronic components 10, a plurality of connecting components 20 for component connection, a plurality of connecting components 30 for external connection, and a wiring substrate 40. The connecting components 20 and 30 are members that form vertical electrical circuits. The connecting components 20 and 30 may also be referred to as "vertical wiring members".

[0024] <3.1 Electronic components and connectors for connecting components> First, we will describe the electronic component 10 and the connecting component 20 for connecting the component. Electronic component 10 is an electronic component mounted on the subunit SU according to the required functions. Electronic component 10 may be, for example, a connector, fuse, relay (e.g., mechanical relay or semiconductor relay), capacitor, branching component, various sensors (e.g., current sensor or voltage sensor), electronic control unit, or an electronic component unit that combines two or more of these. The type of electronic component 10 is not limited to the above examples. Electronic component 10 may be, for example, a heat-generating component that generates heat when energized. Below, a first type electronic component 10M and a second type electronic component 10N will be described as examples of electronic component 10.

[0025] The connecting component 20 is a component that electrically connects the electronic component 10 and the wiring substrate 40. The connecting component 20 forms part of the current-carrying circuit in the subunit SU. The connecting component 20 is made of metal (for example, copper or a copper alloy). The connecting component 20 may also be referred to as a "metal component". Below, a first type of connecting component 20M and a second type of connecting component 20N will be described as examples of the connecting component 20.

[0026] <3.1.1 Type 1 Electronic Components> Figure 5 is a perspective view showing a first type electronic component 10M and a first type connecting component 20M. The first type electronic component 10M is an electronic component in which a plurality of terminals 13 are arranged in a row at one end of the electronic component 10M. The electronic component 10M has, for example, a case 11, a component body 12, a plurality of terminals 13, and a plurality of mounting parts 14.

[0027] (case) The case 11 is an outer casing that forms most of the external shape of the electronic component 10M. The case 11 is made of, for example, synthetic resin and has insulating properties. The case 11 houses the component body 12. The case 11 and the component body 12 may be formed as a single unit.

[0028] In this embodiment, the case 11 has insulating ribs 11a that protrude horizontally (e.g., in the X direction) and extend in the Z direction. The insulating ribs 11a are, for example, plate-shaped and aligned horizontally (e.g., in the X direction) and in the Z direction. The insulating ribs 11a extend, for example, along the entire length of the case 11 in the Z direction. The insulating ribs 11a are positioned between a plurality of terminals 13 (terminals 13A and 13B, described later). The insulating ribs 11a electrically insulate terminals 13A and 13B. In this embodiment, a portion of the insulating ribs 11a is positioned between the first portions 21 (described later) of two connecting components 20M connected to the electronic component 10M. The insulating ribs 11a electrically insulate between the first portions 21 of the two connecting components 20M connected to the electronic component 10M.

[0029] (Main part of the component) The main body of the component 12 is the part that performs the main function of the electronic component 10M. For example, if the electronic component 10M is a relay, the main body of the component 12 includes a switching part (e.g., a contact part) that switches between a conductive state and a non-conductive state. For example, if the electronic component 10M is a fuse, the main body of the component 12 includes a fuse that melts when an overcurrent flows. For example, if the electronic component 10M is a capacitor, the main body of the component 12 includes a part that stores electric charge.

[0030] (Terminals) Terminal 13 is an electrical connection part exposed to the outside of case 11. Terminal 13 is electrically connected to the component body 12 inside case 11. In this embodiment, the electronic component 10M includes terminals 13A and terminal 13B as a plurality of terminals 13. One of terminals 13A and terminal 13B is the positive terminal. The other of terminals 13A and terminal 13B is the negative terminal. One of terminals 13A and terminal 13B is an example of a "first terminal". The other of terminals 13A and terminal 13B is an example of a "second terminal".

[0031] In this embodiment, terminals 13A and 13B are provided at one end of the electronic component 10M in the horizontal direction (e.g., the X direction). Terminals 13A and 13B are arranged side by side in the horizontal direction (e.g., the Y direction). Each terminal 13 has a mounting hole 13h into which a fastening member 71 (e.g., a screw or bolt), described later, is attached. The mounting hole 13h opens in the horizontal direction (e.g., the X direction). The inner circumferential surface of the mounting hole 13h of the electronic component 10M has a screw groove.

[0032] (Mounting part) The mounting portion 14 is a part for fixing the electronic component 10M. The mounting portion 14 has a mounting hole 14h into which a fastening member 112 (for example, a screw or bolt, see Figure 11) described later is attached. The mounting hole 14h opens in the Z direction. The mounting hole 14h is a through hole through which the fastening member 112 passes. The destination for fixing the mounting portion 14 will be described later.

[0033] <3.1.2 Type 1 Connectors> The first type of connecting component 20M is a component that electrically connects the first type of electronic component 10M to the routing board 40. In this embodiment, the connecting component 20M electrically connects the electronic component 10M to the busbar 42 (see Figure 8) included in the routing board 40. In this embodiment, the width L12 of the connecting component 20M in the longitudinal direction (e.g., X direction) of the electronic component 10M is smaller than the longitudinal width L11 of the electronic component 10M. The connecting component 20M has, for example, a first portion 21 and a second portion 22.

[0034] (Part 1) The first portion 21 of the connecting component 20M is the portion that connects to the terminal 13 of the electronic component 10M. The first portion 21 is a plate-like or rectangular parallelepiped portion that extends in the Z direction. The first portion 21 extends in the Z direction along one end of the electronic component 10M (for example, the end in the X direction). The first portion 21 is an upright portion that stands upright in the Z direction relative to the routing substrate 40 (for example, relative to the bus bar 42 described later). The first portion 21 is adjacent to the electronic component 10M in the horizontal direction (for example, the X direction). For example, the first portion 21 is adjacent to the terminal 13 of the electronic component 10M in the horizontal direction (for example, the X direction) and is connected to the terminal 13 of the electronic component 10M from the horizontal direction (for example, the X direction).

[0035] The first portion 21 of the connecting component 20M has a first mounting hole 21h through which a fastening member 71 (e.g., a screw or bolt) is passed. The first mounting hole 21h opens horizontally (e.g., in the X direction). The first portion 21 also has a recess 25 around the first mounting hole 21h. The recess 25 is a accommodating part that houses the head of the fastening member 71 inserted into the first mounting hole 21h. The first portion 21 is physically and electrically connected to the terminal 13 of the electronic component 10M by the fastening member 71 passed through the first mounting hole 21h engaging with the mounting hole 13h of the terminal 13 of the electronic component 10M. Note that the first portion 21 does not necessarily have a recess 25.

[0036] (Second part) The second portion 22 of the connecting component 20M is the portion that connects to the bus bar 42 (see Figure 8). The second portion 22 protrudes horizontally (e.g., in the X direction) from the -Z direction end of the first portion 21. The second portion 22 is a plate portion that runs horizontally. The second portion 22 is adjacent to the bus bar 42 in the Z direction and connects to the bus bar 42 from the Z direction. The second portion 22 of the connecting component 20M is attached from the Z direction to a fastening member 43 (e.g., a screw or bolt, see Figure 8) that protrudes from the bus bar 42 in the +Z direction, and is physically and electrically connected to the bus bar 42. In this embodiment, the second portion 22 of the connecting component 20M has a second mounting hole 22h through which the fastening member 43 passes. The second mounting hole 22h is open in the Z direction. The second portion 22 has the fastening member 43 passing through the second mounting hole 22h. Then, the second portion 22 is fixed to the busbar 42 by engaging the tip of the fastening member 43, which is passed through the second mounting hole 22h, with the engaging member 44 (for example, a nut, see Figure 3). In this embodiment, the first portion 21 and the second portion 22 form an L-shaped single connecting component 20M.

[0037] <3.1.3 Second Type Electronic Components> Figure 6 is a perspective view showing a second type electronic component 10N and a second type connecting component 20N. The second type electronic component 10N is an electronic component in which two terminals 13 are arranged separately at both horizontal ends of the electronic component 10N. The electronic component 10N has, for example, a case 11, a component body 12, and multiple terminals 13. In the configuration of the electronic component 10N, components that have the same function as the electronic component 10M are denoted by the same reference numerals. In this case, the explanation of the electronic component 10N can be read by replacing "electronic component 10M" with "electronic component 10N" in the explanation of the electronic component 10M described above.

[0038] In the electronic component 10N, terminals 13A and 13B are arranged separately at both ends of the electronic component 10N in the horizontal direction (e.g., the X direction). Each terminal 13 has a mounting hole 13h into which a fastening member 72 (e.g., a screw or bolt), described later, is attached. The mounting hole 13h opens in the Z direction. For example, the mounting hole 13h of the electronic component 10N is a through hole through which the fastening member 72 passes. One of terminals 13A and 13B is an example of a "first terminal". The other of terminals 13A and 13B is an example of a "second terminal".

[0039] <3.1.4 Type 2 Connectors> The second type of connecting component 20N is a component that electrically connects the second type of electronic component 10N to the routing substrate 40. In this embodiment, the connecting component 20N electrically connects the electronic component 10N to the busbar 42 (see Figure 8) included in the routing substrate 40. In this embodiment, the width L12 of the connecting component 20N in the longitudinal direction (e.g., X direction) of the electronic component 10N is smaller than the longitudinal width L11 of the electronic component 10N. The connecting component 20N has, for example, a first part 21, a second part 22, and a third part 23.

[0040] (Part 1) The first portion 21 of the connecting component 20N is the portion that connects to the terminal 13 of the electronic component 10N. The first portion 21 is a rectangular parallelepiped portion that extends in the Z direction. The first portion 21 is an upright portion that stands upright in the Z direction relative to the routing substrate 40 (for example, relative to the bus bar 42). The first portion 21 is adjacent to the terminal 13 of the electronic component 10N in the Z direction and connects to the terminal 13 of the electronic component 10N from the Z direction. The first portion 21 of the connecting component 20N has a first mounting hole 21h into which a fastening member 72 engages. The first mounting hole 21h opens in the Z direction. The inner circumferential surface of the first mounting hole 21h of the connecting component 20N has a screw groove. The first portion 21 is physically and electrically connected to the terminal 13 of the electronic component 10N by the fastening member 72, which is passed through the mounting hole 13h of the terminal 13 of the electronic component 10N, engaging with the mounting hole 21h of the first portion 21.

[0041] (Second part) The second portion 22 of the connecting component 20N is the portion that connects to the bus bar 42 (see Figure 8). The second portion 22 protrudes horizontally (e.g., in the X direction) from the -Z direction end of the first portion 21. The second portion 22 is a plate portion that runs horizontally. The second portion 22 is adjacent to the bus bar 42 in the Z direction and connects to the bus bar 42 from the Z direction. The second portion 22 of the connecting component 20N is attached from the Z direction to a fastening member 43 (e.g., a screw or bolt, see Figure 8) that protrudes from the bus bar 42 in the +Z direction, and is physically and electrically connected to the bus bar 42. In this embodiment, the second portion 22 of the connecting component 20N has a second mounting hole 22h through which the fastening member 43 passes. The second mounting hole 22h is open in the Z direction. The fastening member 43, described later, passes through the second mounting hole 22h of the second portion 22. Then, the second portion 22 is fixed to the busbar 42 by engaging the tip of the fastening member 43, which is passed through the second mounting hole 22h, with the engaging member 44 (for example, a nut, see Figure 3).

[0042] (3rd part) The third part 23 is an upright wall (side wall) that rises in the +Z direction from both horizontal ends of the second part 22. The third part 23 is a wall along the Z direction. The third part 23 is connected to the first part 21 and also to the second part 22. The third part 23 extends with an inclination such that it increases in the X direction as it moves in the -Z direction, for example. The third part 23 may be provided on the connecting component 20M described above. On the other hand, the connecting component 20N does not have to have the third part 23.

[0043] <3.1.5 Structure of connecting components> In this embodiment, the connecting component 20 (for example, connecting component 20M and connecting component 20N) is a heat storage member (heat absorption member) that increases the heat capacity of the current-carrying path of the electrical connection unit 1. The connecting component 20 stores (absorbs) at least a portion of the heat emitted by the electronic component 10, for example. Alternatively / in addition, the connecting component 20 may also store (absorb) at least a portion of the heat emitted by the busbar 42 itself when energized. The connecting component 20 may be referred to as a "heat storage component" or a "heat absorption component".

[0044] In this embodiment, the busbar 42 is positioned at a distance from the terminal 13 of the electronic component 10 (for example, at a distance in the Z direction). The connecting component 20 is positioned between the electronic component 10 and the busbar 42. In this disclosure, "the connecting component is positioned between the electronic component and the busbar" is not limited to cases where a portion of the connecting component is located between the electronic component and the busbar when viewed from the X or Y direction. "The connecting component is positioned between the electronic component and the busbar" may also refer to cases where a portion of the connecting component is located between the electronic component and the busbar when viewed from a direction inclined with respect to the X or Y direction. The connecting component 20 electrically connects the terminal 13 of the electronic component 10 and the busbar 42.

[0045] In this embodiment, the thickness of at least a portion of the connecting component 20 is greater than the thickness (thickness in the Z direction) T3 of the busbar 42 (see Figure 13). For example, the thickness T1 in the X direction of at least a portion of the connecting component 20 is greater than the thickness T3 of the busbar 42. In this embodiment, the thickness T1 in the X direction of the first portion 21 of the connecting component 20 is greater than the thickness T3 of the busbar 42. In this embodiment, the first portion 21 has a thickness T1 in the X direction that is greater than the thickness T3 of the busbar 42 as a thickness over its entire length in the Z direction. The thickness T1 in the X direction of the first portion 21 of the connecting component 20 is, for example, more than twice the thickness T3 of the busbar 42. In another view, the thickness T2 in the Z direction of the second portion 22 of the connecting component 20 may be greater than the thickness T3 of the busbar 42.

[0046] In this embodiment, the thickness T1 in the X direction of the first portion 21 of the connecting component 20 is greater than the thickness T2 in the Z direction of the second portion 22 of the connecting component 20. In this embodiment, the first portion 21 has a thickness T1 in the X direction that is greater than the thickness T2 in the Z direction of the second portion 22, over its entire length in the Z direction.

[0047] <3.2 Connection components for external connections> Next, we will describe the connection component 30 for external connection. Figure 7 is a perspective view showing a connecting component 30 for external connection. The connecting component 30 is a component that electrically connects the external connection bus bar 76 and the wiring board 40. In this embodiment, the connecting component 30 electrically connects the external connection bus bar 76 and the bus bar 42 (see Figure 8) included in the wiring board 40. The external connection bus bar 76 is electrically connected to an external device. In this disclosure, "external device" refers to an electrical device located outside the electrical connection unit 1. The external device is, for example, a battery unit mounted on a vehicle or an inverter for driving the vehicle's motor, but is not limited to these examples. The connecting component 30 has, for example, a first part 31, a second part 32, and a third part 33.

[0048] (Part 1) The first portion 31 is the portion that connects to the external bus bar 76. The first portion 31 is a rectangular parallelepiped portion that extends in the Z direction. The first portion 31 is an upright portion that stands upright in the Z direction relative to the routing base plate 40 (for example, relative to the bus bar 42). The first portion 31 is adjacent to the external bus bar 76 in the Z direction and connects to the external bus bar 76 from the Z direction. The first portion 31 has a first mounting hole 31h through which a fastening member 73 (for example, a screw or bolt) passes. The first mounting hole 31h opens in the Z direction. The inner circumferential surface of the first mounting hole 31h has a screw groove. The first portion 31 is physically and electrically connected to the external bus bar 76 by the fastening member 73, which is passed through the mounting hole 76h of the external bus bar 76, engaging with the mounting hole 31h of the first portion 31.

[0049] (Second part) The second portion 32 is the portion that connects to the busbar 42 (see Figure 8). The second portion 32 protrudes horizontally (e.g., in the X direction) from the -Z direction end of the first portion 31. The second portion 32 is a plate portion that runs horizontally. The second portion 32 is adjacent to the busbar 42 in the Z direction and connects to the busbar 42 from the Z direction. The second portion 32 is attached from the Z direction to a fastening member 43 (e.g., a screw or bolt, see Figure 8) that protrudes from the busbar 42 in the +Z direction, and is physically and electrically connected to the busbar 42. In this embodiment, the second portion 32 has a second mounting hole 32h through which the fastening member 43 passes. The second mounting hole 32h is open in the Z direction. The fastening member 43, described later, passes through the second mounting hole 32h of the second portion 32. Then, the second portion 32 is fixed to the busbar 42 by engaging the tip of the fastening member 43, which is passed through the second mounting hole 32h, with the engaging member 44 (for example, a nut, see Figure 3).

[0050] (3rd part) The third part 33 is an upright wall (side wall) that rises in the +Z direction from both horizontal ends of the second part 32. The third part 33 is a wall that runs along the Z direction. The third part 33 is connected to the first part 31 and also to the second part 32. The third part 33 extends with an inclination such that it increases in the X direction (or Y direction) as it proceeds in the -Z direction, for example. Note that the connecting part 30 does not necessarily have to have the third part 33.

[0051] Furthermore, the dimensional relationships between the connecting component 20 and the busbar 42 described above (for example, the dimensional relationships related to thicknesses T1, T2, and T3) are the same for the connecting component 30 to which the external connecting busbar 76 is connected. For example, the explanation of the connecting component 30 can be given by replacing "connecting component 20" with "connecting component 30", "first part 21" with "first part 31", and "second part 22" with "second part 32" in the explanation of the connecting component 20 described above.

[0052] <3.3 Circuit board for cable routing> Next, the wiring substrate 40 will be described. Figure 8 is a perspective view showing the wiring substrate 40. The wiring substrate 40 is a component that forms at least a portion of the electrical conduction paths between a plurality of electronic components 10, and / or at least a portion of the electrical conduction paths between the electronic components 10 and external equipment. In this disclosure, "wiring substrate" means a substrate-type wiring structure. "Substrate-type" means that, when viewed as a whole, regardless of the fine shape, it is in the shape of a plate along a single plane. In this disclosure, "plate-like," "sheet-like," or "plane" is not limited to cases where it is perfectly flat, but may include cases where there are fixing structures or ribs protruding in the Z direction, or where there are uneven shapes on the surface that follow the thickness of the busbars. In this embodiment, the wiring substrate 40 is in the shape of a plate along the X and Y directions.

[0053] The cable routing substrate 40 includes, for example, a base plate 41, one or more (e.g., multiple) busbars 42, and multiple fastening members 43. In this embodiment, the base plate 41 and the multiple busbars 42 are integrated by insert molding. For example, the cable routing substrate 40 is formed as a single piece by insert molding of the busbars 42 with the base plate 41 after the fastening members 43 have been fixed to the busbars 42. That is, the busbars 42 are integrated with the base plate 41 without using fastening members such as screws or bolts. The cable routing substrate 40 may be formed by a different structure instead of insert molding. Modified examples in which the cable routing substrate 40 is formed by a different structure will be described later.

[0054] Figure 9 is a perspective view showing the cable routing board 40 in a partially disassembled state. For the sake of convenience, the base plate 41, bus bar 42, and fastening member 43 will be described below with reference to the partially disassembled drawing of the cable routing board 40.

[0055] (Base plate) The base plate 41 is a holding member that integrally holds a plurality of busbars 42 arranged horizontally with spacing between them. The base plate 41 is made of, for example, synthetic resin and has insulating properties. The base plate 41 electrically insulates the plurality of busbars 42. The base plate 41 is an example of a "base member". The base plate 41 may also be called an "insulating substrate". The base plate 41 has, for example, a flat portion 51 and a plurality of fixing portions 52. The fixing portions 52 will be described later.

[0056] The flat portion 51 is a plate-shaped part formed within the base plate 41. The flat portion 51 is plate-shaped and oriented horizontally. The flat portion 51 forms the main part of the base plate 41. The flat portion 51 forms the base (insulating base) of the base plate 41. In this embodiment, the flat portion 51 extends across the entire width of the base plate 41 in the X direction, except for the four corners of the base plate 41, and also extends across the entire width of the base plate 41 in the Y direction.

[0057] The planar portion 51 has a first surface 51a and a second surface 51b. The first surface 51a is a surface oriented in the +Z direction. The first surface 51a is a plane that aligns with the horizontal direction. The first surface 51a faces multiple electronic components 10 and also faces the insulating cover 93 (see Figure 1) of the electrical connection unit 1. The second surface 51b is located on the opposite side from the first surface 51a. The second surface 51b is a surface oriented in the -Z direction. The second surface 51b is a plane that aligns with the horizontal direction. The second surface 51b faces the metal plate 80 (see Figure 1). The thickness direction (plate thickness direction) of the planar portion 51 is the Z direction.

[0058] The planar portion 51 has, for example, one or more (e.g., multiple) housing portions 55, each of which accommodates a busbar 42. The multiple housing portions 55 are formed apart from each other in the X or Y direction. Each housing portion 55 is, for example, a through hole that penetrates the planar portion 51 in the Z direction. Alternatively, the housing portion 55 may be a recess provided on the first surface 51a or the second surface 51b of the planar portion 51 and recessed in the Z direction. In this disclosure, "the housing portion penetrates the planar portion in the first direction (Z direction)" may also include cases where a portion of the total length of the housing portion 55 penetrates the planar portion 51 in the Z direction (for example, the remaining portion of the housing portion 55 may be a recess recessed in the Z direction, or it may be provided inside the base plate 41 and not exposed to the outside of the base plate 41). Similarly, in this disclosure, "the housing portion is recessed in the first direction (Z direction)" may also include cases where a portion of the total length of the housing portion 55 is recessed in the Z direction (for example, the remaining portion of the housing portion 55 may be a through hole penetrating the planar portion 51 in the Z direction, or it may be provided inside the base plate 41 and not exposed to the outside of the base plate 41).

[0059] Each housing section 55 has an external shape corresponding to the shape of the bus bar 42 it houses when viewed from the Z direction. In this embodiment, the planar section 51 includes, for example, five housing sections 55A, 55B, 55C, 55D, and 55E as a plurality of housing sections 55. Housing section 55A is provided in correspondence with the bus bar 42A described later and houses the bus bar 42A. Housing section 55B is provided in correspondence with the bus bar 42B described later and houses the bus bar 42B. Housing section 55C is provided in correspondence with the bus bar 42C described later and houses the bus bar 42C. Housing section 55D is provided in correspondence with the bus bar 42D described later and houses the bus bar 42D. Housing section 55E is provided in correspondence with the bus bar 42E described later and houses the bus bar 42E.

[0060] At least the surface of the base plate 41 may have a color that has a higher thermal emissivity than the bus bar 42. For example, at least the surface of the base plate 41 may be colored black. The base plate 41 having a specific color can be achieved by painting the surface of the base plate 41 with the specific color, or the material of the base plate 41 itself may have the specific color. If at least the surface of the base plate 41 has a color that has a higher thermal emissivity than the bus bar 42, heat dissipation from the base plate 41 can be further promoted.

[0061] (Bus bar) The busbar 42 is a routing member (electrical connection member) included in the routing substrate 40. The busbar 42 is, for example, a routing member for electrically connecting a plurality of electronic components 10. Alternatively, the busbar 42 may be a routing member for connecting the electronic components 10 to an external device. The busbar 42 is made of metal (for example, copper or a copper alloy) and is conductive. In this embodiment, the routing substrate 40 has a plurality of busbars 42, for example, five busbars 42A, 42B, 42C, 42D, and 42E. The five busbars 42A, 42B, 42C, 42D, and 42E are arranged horizontally with space between them. The five busbars 42A, 42B, 42C, 42D, and 42E include portions that are arranged on the same plane. The five busbars 42A, 42B, 42C, 42D, and 42E are held in place by the flat portion 51 of the base plate 41.

[0062] At least a portion of each busbar 42 is plate-shaped and oriented horizontally. At least a portion of each busbar 42 is housed in the housing 55 and extends along the planar portion 51. That is, at least a portion of each busbar 42 extends along the first surface 51a of the planar portion 51. At least a portion of each busbar 42 extends horizontally within the housing 55. In this embodiment, each busbar 42 is plate-shaped and oriented horizontally throughout its entire length. Each busbar 42 is housed in the housing 55 and extends along the planar portion 51 throughout its entire length. Hereinafter, the portion of each busbar 42 that is housed in the housing 55 and extends along the planar portion 51 may be referred to as the "plate portion 42p". The busbar 42 is a member that forms a horizontal electrical circuit. The busbar 42 may also be referred to as a "horizontal wiring member".

[0063] Figure 10 is a plan view showing the wiring substrate 40. Each busbar 42 has, for example, a first connecting portion 61, a second connecting portion 62, and an extended portion 63.

[0064] The first connection portion 61 is the part that contacts one connection component 20 (hereinafter referred to as "first connection component 20"). The first connection component 20 is a connection component that connects one electronic component 10 (hereinafter referred to as "first electronic component 10") to the bus bar 42. The first connection portion 61 is the part 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 and is connected to the first connection component 20 from the Z direction.

[0065] The second connection portion 62 is the portion that contacts another connection component 20 (hereinafter referred to as "second connection component 20"). The second connection component 20 is a connection component that connects another electronic component 10 (hereinafter referred to as "second electronic component 10") included in the plurality of electronic components 10 to the bus bar 42. The second connection portion 62 is the portion of the bus bar 42 that overlaps with the second connection component 20 when viewed from the Z direction. The second connection portion 62 is adjacent to the second connection component 20 in the Z direction and is connected to the second connection component 20 from the Z direction.

[0066] Note that the second connection portion 62 may be a portion that contacts another connection component 30 (hereinafter referred to as "second connection component 30") instead of the above example. The connection component 30 is a connection component for connecting an external device to the busbar 42. In this case, the second connection portion 62 is the portion of the busbar 42 that overlaps with the second connection component 30 when viewed from the Z direction. The second connection portion 62 is adjacent to the second connection component 30 in the Z direction and is connected to the second connection component 30 from the Z direction.

[0067] Alternatively, the second connection portion 62 may be a portion that contacts a connecting busbar 75 for connecting to another subunit SU, instead of the connection parts 20 and 30. In this case, the second connection portion 62 is the portion of the busbar 42 that overlaps with the connecting busbar 75 when viewed from the Z direction. The second connection portion 62 is adjacent to the connecting busbar 75 in the Z direction and is connected to the connecting busbar 75 from the Z direction.

[0068] The extension portion 63 extends from the first connecting portion 61 in the X or Y direction. The extension portion 63 is provided between the first connecting portion 61 and the second connecting portion 62. The extension portion 63 extends across the first connecting portion 61 and the second connecting portion 62. The extension portion 63 connects the first connecting portion 61 and the second connecting portion 62.

[0069] In this embodiment, the first connecting portion 61, the second connecting portion 62, and the extension portion 63 are plate-shaped and oriented horizontally. In this embodiment, each busbar 42 is housed in the housing portion 55 over at least the first connecting portion 61 and the second connecting portion 62 and extends along the planar portion 51. For example, the first connecting portion 61, the second connecting portion 62, and the extension portion 63 are housed in the housing portion 55 and extend along the planar portion 51.

[0070] In this embodiment, the extensions 63 of some busbars 42 are housed in the housing 55, so that they extend across both sides of region R, which overlaps with the electronic component 10 when viewed from the Z direction. For example, the extensions 63 extend in a straight line along the X direction. The extensions 63 extend across the region R that overlaps with the electronic component 10 when viewed from the Z direction, so that they extend across the +X and -X sides of region R. In other words, by being housed in the housing 55, the busbars 42 can be routed along a better path (for example, a shorter path) without being obstructed by the presence of the electronic component 10.

[0071] Furthermore, one or more busbars 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 busbar 42 that is extended for the purpose of increasing the heat dissipation area and / or increasing the heat capacity for heat storage (heat absorption). The extension portion 64 is a portion that is 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 is plate-shaped and oriented horizontally. The extension portion 64 is housed in the housing portion 55 and extends along the planar portion 51. The extension portion 64 extends to a region R that overlaps with the electronic component 10 when viewed from the Z direction, and has the end 42e1 of the busbar 42 at a position that overlaps with the electronic component 10 when viewed from the Z direction.

[0072] The following describes some routing examples for the busbar 42. Note that multiple electronic components 10 include three electronic components 10A, 10B, and 10C. Electronic components 10A and 10B are, for example, first-type electronic components 10M. Electronic component 10C is, for example, second-type electronic component 10N. Note that the types of electronic components 10 are not limited to the above examples. Also, multiple connecting components 20 include six connecting components 20A, 20B, 20C, 20D, 20E, and 20F. Multiple connecting components 30 include two connecting components 30A and 30B. Multiple connecting busbars 75 include two connecting busbars 75A and 75B. Multiple external connection busbars 76 include two external connection busbars 76A and 76B.

[0073] (1st wiring example) First, an example of wiring for busbar 42A will be described. Busbar 42A has a first connection part 61, a second connection part 62, and an extension part 63. The first connection part 61 is located on the +X side relative to the electronic component 10A when viewed from the Z direction. The first connection part 61 is electrically connected to terminal 13A of the electronic component 10A via a connection part 20A, which is the first connection part 20. The second connection part 62 is located on the -X side relative to the electronic component 10A when viewed from the Z direction. The second connection part 62 is electrically connected to another subunit SU via a connecting busbar 75A.

[0074] The extension portion 63, housed in the housing portion 55, extends across both sides of region R, which overlaps with the electronic component 10A when viewed from the Z direction. For example, the extension portion 63 extends in a straight line along the X direction. The extension portion 63 extends across the region R, which overlaps with the electronic component 10A when viewed from the Z direction, to both the +X and -X sides of region R. The busbar 42A is, for example, a busbar included in the positive electrode line PL of the electrical connection unit 1.

[0075] (Second wiring example) Next, an example of wiring for the busbar 42B will be described. The busbar 42B has a first connection part 61, a second connection part 62, an extension part 63, and an extension part 64. The first connection part 61 is electrically connected to the terminal 13B of the electronic component 10A via a connection part 20B, which is the first connection part 20. The second connection part 62 is electrically connected to the external connection busbar 76A via a connection part 30A, which is the second connection part 30. The extension part 64 extends to a region R that overlaps with the electronic component 10A when viewed from the Z direction, and has the end 42e1 of the busbar 42 at a position that overlaps with the electronic component 10A. Note that, similar to the busbar 42A, the busbar 42B may have an extension part 63 that extends through the region R that overlaps with the electronic component 10 when viewed from the Z direction, and spans both sides of the region R. The busbar 42B is, for example, a busbar included in the positive electrode line PL of the electrical connection unit 1.

[0076] (3rd wiring example) Next, an example of busbar 42C routing will be described. Busbar 42C has a first connection part 61, a second connection part 62, an extension part 63, and an extension part 64. The first connection part 61 is electrically connected to terminal 13B of electronic component 10B via a connection part 20C, which is a first connection part 20. The second connection part 62 is electrically connected to another subunit SU via a connecting busbar 75B. The extension part 64 extends to a region R that overlaps with electronic component 10B when viewed from the Z direction, and has an end 42e1 of busbar 42 at a position that overlaps with electronic component 10B when viewed from the Z direction. Busbar 42C is, for example, a busbar included in the negative electrode line NL of electrical connection unit 1.

[0077] (4th wiring example) Next, an example of a busbar 42D will be described. The busbar 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 terminal 13A of electronic component 10B via connection portion 20D, which is a first connection component 20. The second connection portion 62 is electrically connected to terminal 13B of electronic component 10C via connection portion 20E, which is a second connection component 20. The busbar 42D is, for example, a busbar included in the negative electrode line NL of the electrical connection unit 1.

[0078] (5th wiring example) Next, an example of wiring for the busbar 42E will be described. The busbar 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 terminal 13A of the electronic component 10C via a connection portion 20F, which is a first connection component 20. The second connection portion 62 is electrically connected to the external connection busbar 76B via a connection portion 30B, which is a second connection component 30. The busbar 42E is, for example, a busbar included in the negative electrode line NL of the electrical connection unit 1.

[0079] (Fastening member) Next, we will return to Figure 9 and explain the fastening member 43. The fastening member 43 is a component for fixing the bus bar 42 to the component to which the bus bar 42 is connected (connecting component 20, connecting component 30, or connecting bus bar 75). The fastening member 43 is, for example, a crimping bolt fixed to the bus bar 42. The fastening member 43 is an example of a "fastening part".

[0080] In this embodiment, each of the first connecting portion 61 and the second connecting portion 62 of the bus bar 42 has a through hole 42h. The through hole 42h penetrates the bus bar 42 in the Z direction. The fastening member 43 is, for example, a bolt having a shaft portion 43a and a head portion 43b. The circumferential surface of the shaft portion 43a has screw grooves. The head portion 43b has a larger diameter than the shaft portion 43a. The fastening member 43 is crimped and fixed to the bus bar 42 with the shaft portion 43a passing through the through hole 42h of the bus bar 42, and the head portion 43b being crimped and fixed to the bus bar 42. With this fixing, the fastening member 43 is electrically and physically connected to the bus bar 42 with the shaft portion 43a protruding from the through hole 42h of the bus bar 42 in the +Z direction. Note that the fastening member 43 is not limited to crimping and may be fixed to the bus bar 42 by welding or other methods.

[0081] In this embodiment, the connecting component 20 is attached to the fastening member 43 from the Z direction, with the connecting component 20 already fixed to the electronic component 10 by the fastening member 71 or fastening member 72. For example, the connecting component 20 is inserted into the mounting hole 22h of the second portion 22 of the fastening member 43 by inserting the shaft portion 43a of the fastening member 43. Then, the engaging member 44 (e.g., a nut) is engaged with the shaft portion 43a of the fastening member 43 that protrudes from the mounting hole 22h of the second portion 22 of the connecting component 20. The engaging member 44 is attached to the shaft portion 43a, for example, along the Z direction. This engagement fixes the second portion 22 of the connecting component 20 to the fastening member 43.

[0082] <4. Metal plate, insulating sheet, heat transfer component, and insulating cover> Next, the metal plate 80, insulating sheet 91, heat transfer member 92, and insulating cover 93 will be described.

[0083] <4.1 Metal Plate> Figure 11 is a perspective view showing a partially disassembled electrical connection unit 1. The metal plate 80 is a component that ensures the rigidity of the electrical connection unit 1 and improves its heat dissipation. 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 component". The metal plate 80 may also be referred to as a "metal component" or a "rigid component".

[0084] The metal plate 80 is rectangular in shape when viewed from the Z direction, oriented 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, separated in the X direction. The third end 80e3 and the fourth end 80e4 are a pair of transverse ends of the metal plate 80, separated in the Y direction. The metal plate 80 includes, for example, a flat portion 81, a plurality of fixing portions 82, and a plurality of fixing portions 83.

[0085] The flat portion 81 is a plate-shaped part within the metal plate 80. The flat portion 81 is plate-shaped and oriented horizontally. The flat portion 81 forms the main part of the metal plate 80. The flat portion 81 forms the base (metal base) of the metal plate 80. In this embodiment, the flat portion 81 is large enough to cover the three subunits SU from below. The flat portion 81 faces, for example, all the electronic components 10 and all the busbars 42 included in the electrical connection unit 1. The flat portion 81 faces the wiring substrate 40 of the three subunits SU. In this embodiment, the metal plate 80 leaves a gap S1 (see Figure 13) between itself and the second surface 51b of the flat portion 51 of each subunit SU, and faces the second surface 51b of the flat portion 51 of each subunit SU.

[0086] The fixing portion 82 is a fixing 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 the base plate 41 of each subunit SU. The fixing portion 82 is a cylindrical or prismatic boss that protrudes in the +Z direction from the flat portion 81 of the metal plate 80. The fixing portion 82 will be described in detail later.

[0087] The fixing portion 83 is a fixing portion for directly fixing the electronic components 10 of each subunit SU to the metal plate 80 without going through 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 components 10 of each subunit SU. The fixing portion 83 is a cylindrical or prismatic boss that protrudes from the planar portion 81 in the +Z direction. The fixing portion 83 will be described in detail later.

[0088] <4.2 Insulating Sheet> The insulating sheet 91 is an insulating member for electrically insulating the metal plate 80 from the busbars 42 of each subunit SU. The insulating sheet 91 is made of a synthetic resin such as polyester or polyimide and has insulating properties. When viewed from the Z direction, the insulating sheet 91 is rectangular. The insulating sheet 91 is a sheet that lies horizontally. The insulating sheet 91 is placed between the flat portion 81 of the metal plate 80 and the routing substrate 40 of each subunit SU. For example, the insulating sheet 91 is placed between the flat portion 81 of the metal plate 80 and a plurality of heat transfer members 92.

[0089] In this embodiment, the insulating sheet 91 is attached to the flat portion 81 of the metal plate 80. The insulating sheet 91 has notches or openings to avoid the fixing portions 82 and 83 of the metal plate 80. Alternatively, the insulating sheet 91 may be provided between the wiring substrate 40 of each subunit SU and the plurality of heat transfer members 92. If the heat transfer members 92 have insulating properties and the necessary insulation is ensured by the heat transfer members 92, the insulating sheet 91 may be omitted.

[0090] <4.3 Heat Transfer Components> The heat transfer member 92 is a member for transferring heat generated by the electronic component 10 when energized, and / or heat generated by the busbar 42 itself (Joule heat) when energized, 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). The heat transfer member 92 is formed of a material with a higher thermal conductivity than, for example, the base plate 41. 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 material.

[0091] Figure 12 is a bottom view showing the wiring substrate 40. In this embodiment, the multiple heat transfer members 92 are partially provided on the wiring substrate 40. For example, the multiple heat transfer members 92 are positioned so as to overlap with a part of the busbar 42 when viewed from the Z direction. More specifically, the multiple heat transfer members 92 are positioned so as to overlap with a part of the busbar 42 near the electronic components 10 (e.g., electronic components 10A, 10B) when viewed from the Z direction. In this embodiment, the multiple heat transfer members 92 are positioned so as to overlap with the connecting components 20 when viewed from the Z direction. Note that the arrangement of the heat transfer members 92 is not limited to the examples described above. For example, the heat transfer members 92 may be positioned so as not to overlap with the connecting components 20 when viewed from the Z direction, or so as not to overlap with the electronic components 10.

[0092] In this embodiment, the multiple heat transfer members 92 include heat transfer members 92S and heat transfer members 92L. Heat transfer member 92L is larger than heat transfer member 92S. Hereinafter, when heat transfer member 92S and heat transfer member 92L are not distinguished, they will simply be referred to as "heat transfer member 92".

[0093] Figure 13 is a cross-sectional view along the line F13-F13 of the structure shown in Figure 10. In this embodiment, the heat transfer member 92 is positioned between the metal plate 80 and the busbar 42. The heat transfer member 92 transfers heat from the electronic component 10 to the busbar 42, and / or heat generated by the busbar 42, from the busbar 42 to the metal plate 80.

[0094] In this embodiment, a portion of the heat transfer member 92 is in contact with the busbar 42 at a position that overlaps with the connecting component 20 when viewed from the Z direction. In this case, the heat transfer member 92 facilitates the transfer of heat from the terminal 13 of the electronic component 10 to the connecting component 20, and from the connecting component 20 to the metal plate 80 via the busbar 42. Alternatively, a portion of the heat transfer member 92 may be in contact with the busbar 42 at a position that overlaps with the connecting component 30 when viewed from the Z direction. In this case, the heat transfer member 92 facilitates the transfer of heat from the external device to the connecting component 30, and from the connecting component 30 to the metal plate 80 via the busbar 42.

[0095] In this embodiment, a portion of the heat transfer member 92 is positioned to overlap with the head 43b of the fastening member 43 when viewed from the Z direction, and is in contact with the head 43b of the fastening member 43. In this case, the heat transfer member 92 can more easily transfer heat from the terminal 13 of the electronic component 10 to the connecting component 20 from the fastening member 43 to the metal plate 80. Also, when a portion of the heat transfer member 92 is in contact with the head 43b of the fastening member 43, the heat transfer member 92 can more easily transfer heat from the external device to the connecting component 30 from the fastening member 43 to the metal plate 80.

[0096] In this embodiment, a portion of the heat transfer member 92 is in contact with the busbar 42 at a position that overlaps with the electronic component 10 when viewed from the Z direction. In this case, the heat transfer member 92 can more easily transfer heat from the electronic component 10 to the busbar 42 and from the busbar 42 to the metal plate 80. In the example shown in Figure 13, the upper surface of the busbar 42 is in contact with the electronic component 10, so the busbar 42 is thermally connected to the electronic component 10. Note that the extension portion 63 or the extended portion 64 may be the part of the busbar 42 that is thermally connected to the electronic component 10.

[0097] (modified version) Figure 14 is a cross-sectional view showing one modified example. In this modified example, an air layer AS, which is a gap, exists between the busbar 42 and the electronic component 10. The busbar 42 is thermally connected to the electronic component 10 via the air layer AS. With this configuration, the heat generated by the electronic component 10 is transferred to the busbar 42 through the air layer AS. The heat transferred to the busbar 42 is then transferred to the metal plate 80 via the heat transfer member 92 and dissipated.

[0098] (modified version) Figure 15 is a cross-sectional view showing another modified example. In this modified example, a heat transfer member 98 is provided between the busbar 42 and the electronic component 10. The heat transfer member 98 is interposed between the busbar 42 and the electronic component 10 in the Z direction. The busbar 42 is thermally connected to the electronic component 10 via the heat transfer member 98. The heat transfer member 98 transfers the heat generated by the electronic component 10 to the busbar 42. The heat transfer member 98 is, for example, an elastic heat transfer sheet (e.g., a thermally conductive silicone sheet). However, the heat transfer member 98 is not limited to the above example and may be a heat transfer member formed from a thermally conductive gel or other material. With this configuration, the heat generated by the electronic component 10 is efficiently transferred to the busbar 42 via the heat transfer member 98. The heat transferred to the busbar 42 is then transferred to the metal plate 80 via the heat transfer member 92 and dissipated.

[0099] <4.4 Insulating Cover> Returning to Figure 1, the insulating cover 93 will be described. The insulating cover 93 is a component for preventing fingers from touching the current-carrying path of the main body 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 the -Z direction side open. The insulating cover 93 has a plurality of ventilation holes 93h. The insulating cover 93 is attached to the metal plate 80 along the Z direction. Note that the insulating cover 93 is not limited to a box-shaped component, but may also be a sheet-like component that covers the current-carrying path of the main body MU.

[0100] <5. Exposed busbar structure> Next, we will describe the exposed structure of the busbar 42.

[0101] <5.1 Exposed structure on the upper side of the busbar> First, with reference to Figure 8, the exposed structure on the upper side of the busbar 42 will be described. In this embodiment, at least a portion of the extended portion 63 of the busbar 42 is exposed to the outside of the base plate 41 on the upper side (the side of the first surface 51a of the planar portion 51). For example, the extended portion 63 of the busbar 42 is exposed to the outside of the base plate 41 on the upper side in at least a portion of the region R (see Figure 10) that overlaps with the electronic component 10 when viewed from the Z direction.

[0102] In this embodiment, the busbar 42 is housed in the housing portion 55 over its entire length, at least between the first connection portion 61 and the second connection portion 62, and extends along the first surface 51a of the planar portion 51. The busbar 42 is exposed to the outside of the base plate 41 on its upper side over its entire length, at least between the first connection portion 61 and the second connection portion 62.

[0103] In this embodiment, the busbar 42 is housed in the housing portion 55 along its entire length and extends along the first surface 51a of the planar portion 51. The busbar 42 is exposed to the outside of the base plate 41 on its upper side along its entire length.

[0104] As shown in Figure 13, at least a portion of the extended portion 63 of the busbar 42 is exposed to the outside of the base plate 41 not only on the upper side but also on the lower side (second surface 51b side). For example, the busbar 42 is exposed to the outside of the base plate 41 on the lower side along its entire length.

[0105] (modified version) Figure 16 is a cross-sectional view showing one modified example. In this modified example, the planar portion 51 of the base plate 41 has a cover portion 51v on the lower side (second surface 51b side) that covers at least a part of the extended portion 63 of the bus bar 42. In the area covered by the cover portion 51v, the bus bar 42 is not exposed on the lower side. The cover portion 51v may be provided along the entire length of the bus bar 42. Note that the cover portion 51v does not have to be provided in areas that overlap with, for example, the heat transfer member 92 when viewed from the Z direction.

[0106] <5.2 Exposed structure on the underside of the busbar> Next, with reference to Figure 13, the exposed structure on the lower side of the busbar 42 will be described. In this embodiment, the plate portion 42p of the busbar 42 includes an exposed portion 42u that is exposed to the outside of the base plate 41 on the lower side (the second surface 51b side of the flat portion 51). In this embodiment, the exposed portion 42u of the busbar 42 extends along the entire length of the busbar 42. In this embodiment, the heat transfer member 92 is positioned between the exposed portion 42u of the busbar 42 and the metal plate 80. For example, the heat transfer member 92 is in contact with the exposed portion 42u of the busbar 42.

[0107] In this embodiment, at least a portion of the exposed portion 42u of the busbar 42 is provided in a region that overlaps with the connecting component 20 when viewed from the Z direction. At least a portion of the heat transfer member 92 overlaps with the exposed portion 42u of the busbar 42 in the region that overlaps with the connecting component 20 when viewed from the Z direction. For example, at least a portion of the heat transfer member 92 is in contact with the exposed portion 42u of the busbar 42 in the region that overlaps with the connecting component 20 when viewed from the Z direction.

[0108] In this embodiment, the exposed portion 42u of the busbar 42 includes a first portion 42ua located in a region that overlaps with the connecting component 20 when viewed from the Z direction, and a second portion 42ub located in a region that overlaps with the electronic component 10 when viewed from the Z direction.

[0109] The heat transfer member 92 includes a first heat transfer section 92a and a second heat transfer section 92b. The first heat transfer section 92a overlaps with the first portion 42ua of the exposed portion 42u of the busbar 42 in the region that overlaps with the connecting component 20 when viewed from the Z direction. For example, the first heat transfer section 92a is in contact with the first portion 42ua of the exposed portion 42u of the busbar 42. On the other hand, the second heat transfer section 92b overlaps with the second portion 42ub of the exposed portion 42u of the busbar 42 in the region that overlaps with the electronic component 10 when viewed from the Z direction. For example, the second heat transfer section 92b is in contact with the second portion 42ub of the exposed portion 42u of the busbar 42.

[0110] As described above, at least a portion of the extended portion 63 of the busbar 42 is exposed to the outside of the base plate 41 not only on the lower side but also on the upper side (first surface 51a side). For example, the busbar 42 is exposed to the outside of the base plate 41 on the upper side along its entire length. For example, the second portion 42ub of the exposed portion 42u of the busbar 42 is exposed to the outside of the base plate 41 on the upper side as well as the lower side and faces the electronic component 10.

[0111] (modified version) Figure 17 is a cross-sectional view showing one modified example. In this modified example, the planar portion 51 of the base plate 41 has a cover portion 51v on the upper side (first surface 51a side) that covers at least a part of the extended portion 63 of the bus bar 42. In the area covered by the cover portion 51v, the bus bar 42 is not exposed on the upper side. The cover portion 51v may be provided along the entire length of the bus bar 42. The cover portion 51v may not be provided in areas that overlap with the first connection portion 61 and the second connection portion 62 when viewed from the Z direction, for example.

[0112] <6. Size and arrangement of heat transfer components> <6.1 Examples of Electronic Component Placement> Figure 18 is a plan view illustrating the size and arrangement of the heat transfer member 92. In this embodiment, the electrical connection unit 1 includes, as the electronic components 10 described above, electronic components 10JA, 10JB, 10JC, 10JD, and 10JE. Each of the electronic components 10JA, 10JB, 10JC, 10JD, and 10JE may be the first type of electronic component 10M described above, or the second type of electronic component 10N described above. In the example shown in Figure 18, the electronic components 10JA, 10JB, 10JC, 10JD, and 10JE are arranged in a plurality of subunits SU. For example, electronic components 10JA and 10JB are provided in subunit SUX. On the other hand, electronic components 10JC, 10JD, and 10JE are provided in subunit SUY.

[0113] In this embodiment, electronic component 10JC generates more heat when energized (when the electrical connection unit 1 is operating) compared to electronic components 10JA, 10JB, 10JD, and 10JE. Electronic components 10JA, 10JB, 10JD, and 10JE are, for example, connectors, fuses, relays (e.g., mechanical relays or semiconductor relays), capacitors, branching components, various sensors (e.g., voltage sensors), electronic control units, or electronic component units that unitize two or more of these. On the other hand, electronic component 10JC is a pyro fuse or a current sensor (e.g., a current sensor with a shunt resistor). However, the types of electronic components 10JA, 10JB, 10JC, 10JD, and 10JE are not limited to the examples described above. Electronic component 10JA is an example of a "first electronic component". Electronic component 10JB is an example of a "second electronic component" and a "component to be connected". Electronic component 10JC is an example of a "third-generation electronic component."

[0114] <6.2 Example of busbar placement> In this embodiment, the electrical connection unit 1 includes the busbars 42 described above: busbar 42JA, busbar 42JB, busbar 42JC, busbar 42JD, busbar 42JE, busbar 42JF, and busbar 42JG. The busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG are arranged horizontally with space between them. The busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG include portions that are arranged on the same plane as each other. The busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG are held by the planar portion 51 of the base plate 41.

[0115] At least a portion of each of the busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG is plate-shaped and oriented horizontally. At least a portion of each of the busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG is housed in the housing 55 and extends along the planar section 51. That is, at least a portion of each of the busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG extends along the first surface 51a of the planar section 51. At least a portion of each of the busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG extends horizontally within the housing 55. In this embodiment, each of the busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG is plate-shaped and extends horizontally along the entire length of the busbar 42. Each of the busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG is housed in the housing section 55 along the entire length of the busbar 42 and extends along the flat section 51. These busbars 42JA, 42JB, 42JC, 42JD, 42JE, 42JF, and 42JG face the metal plate 80 in the Z direction.

[0116] (Bus bar 42JA) The busbar 42JA electrically connects terminal 13A of electronic component 10JA to terminal 13A of electronic component 10JB. In this embodiment, the first connection portion 61 of the busbar 42JA is located on the +X side relative to electronic component 10JA when viewed from the Z direction. The first connection portion 61 of the busbar 42JA is electrically connected to terminal 13A of electronic component 10JA via a connecting component 20 (connecting component 20JA). The second connection portion 62 of the busbar 42JA is electrically connected to terminal 13A of electronic component 10JB via another connecting component 20. Terminal 13A of electronic component 10JA is an example of a "first terminal". The busbar 42JA is an example of a "first busbar". The connecting component 20JA is an example of a "first connecting component".

[0117] (Busbar 42JB) The busbar 42JB electrically connects terminal 13B of electronic component 10JB to another electronic component 10 or connecting component 30. For example, the first connection portion 61 of the busbar 42JB is electrically connected to terminal 13B of electronic component 10JB via connecting component 20. The second connection portion 62 of the busbar 42JB is electrically connected to another electronic component 10 or connecting component 30.

[0118] (Bus bar 42JC) Busbar 42JC electrically connects terminal 13B of electronic component 10JA to terminal 13A of electronic component 10JC. In this embodiment, the first connection portion 61 of busbar 42JC is located on the +X side relative to electronic component 10JA when viewed from the Z direction. The first connection portion 61 of busbar 42JC is electrically connected to terminal 13B of electronic component 10JA via connection component 20 (connection component 20JB). The second connection portion 62 of busbar 42JC is located on the -X side relative to electronic component 10JA when viewed from the Z direction. The second connection portion 62 of busbar 42JC is electrically connected to connecting busbar 75, and is electrically connected to terminal 13A of electronic component 10JC via connecting busbar 75 and busbar 42JD. Terminal 13B of electronic component 10JA is an example of a "second terminal". Busbar 42JC is an example of a "second busbar". The connector part 20JB is an example of a "second connector part".

[0119] (Bus bar 42JD) Busbar 42JD electrically connects busbar 42JC to terminal 13A of electronic component 10JC. In this embodiment, the first connection portion 61 of busbar 42JD is electrically connected to connecting busbar 75. The second connection portion 62 of busbar 42JD is electrically connected to terminal 13A of electronic component 10JC via connecting component 20.

[0120] (Bus bar 42JE) The busbar 42JE electrically connects terminal 13B of electronic component 10JC and terminal 13A of electronic component 10JD. In this embodiment, the first connection portion 61 of the busbar 42JE is electrically connected to terminal 13B of electronic component 10JC via the connection component 20. The second connection portion 62 of the busbar 42JE is electrically connected to terminal 13A of electronic component 10JD via the connection component 20.

[0121] (Bus bar 42JF) The busbar 42JF electrically connects terminal 13B of electronic component 10JD and terminal 13A of electronic component 10JE. In this embodiment, the first connection portion 61 of the busbar 42JF is electrically connected to terminal 13B of electronic component 10JD via the connection component 20. The second connection portion 62 of the busbar 42JF is electrically connected to terminal 13A of electronic component 10JE via the connection component 20.

[0122] (Bus bar 42JG) Busbar 42JG electrically connects terminal 13B of electronic component 10JD to another electronic component 10. In this embodiment, the first connection portion 61 of busbar 42JG is electrically connected to terminal 13B of electronic component 10JD via connection component 20. On the other hand, the second connection portion 62 of busbar 42JF is electrically connected to another electronic component 10 via connection component 20.

[0123] <6.3 Example of heat transfer component arrangement> In this embodiment, the electrical connection unit 1 includes, as described above, a plurality of heat transfer members 92S (heat transfer members 92SA, 92SB, 92SC, 92SD) and a plurality of heat transfer members 92L (heat transfer members 92LA, 92LB).

[0124] (Heat transfer component 92SA) The heat transfer member 92SA is positioned between the busbar 42JA and the flat portion 81 of the metal plate 80, and transfers heat from the busbar 42JA to the metal plate 80. For example, a portion of the heat transfer member 92SA overlaps with the electronic component 10JA when viewed from the Z direction. Another portion of the heat transfer member 92SA overlaps with the connecting component 20JA that connects the electronic component 10JA and the busbar 42JA when viewed from the Z direction. The heat transfer member 92SA is an example of a "first heat transfer member".

[0125] (Heat transfer component 92LA) The heat transfer member 92LA is positioned between the bus bar 42JC and the flat portion 81 of the metal plate 80, and transfers heat from the bus bar 42JC to the metal plate 80. For example, the heat transfer member 92LA A portion of the heat transfer member 92LA overlaps with the electronic component 10JA when viewed from the Z direction. Another portion of the heat transfer member 92LA overlaps with the connecting component 20JB that connects the electronic component 10JA and the busbar 42JC when viewed from the Z direction. The heat transfer member 92LA is an example of a "second heat transfer member".

[0126] (Heat transfer component 92LB) The heat transfer member 92LB is positioned between the busbar 42JE and the flat portion 81 of the metal plate 80, and transfers heat from the busbar 42JE to the metal plate 80. For example, a portion of the heat transfer member 92LB overlaps with the electronic component 10JD when viewed from the Z direction. Another portion of the heat transfer member 92LB overlaps with the connecting component 20 that connects the electronic component 10JD and the busbar 42JE when viewed from the Z direction.

[0127] (Heat transfer component 92SB) The heat transfer member 92SB is positioned between the busbar 42JF and the flat portion 81 of the metal plate 80, and transfers heat from the busbar 42JF to the metal plate 80. For example, a portion of the heat transfer member 92SB overlaps with the electronic component 10JD when viewed from the Z direction. Another portion of the heat transfer member 92SB overlaps with the connecting component 20 that connects the electronic component 10JD and the busbar 42JF when viewed from the Z direction.

[0128] (Heat transfer component 92SC) The heat transfer member 92SC is positioned between the busbar 42JF and the flat portion 81 of the metal plate 80, and transfers heat from the busbar 42JF to the metal plate 80. For example, a portion of the heat transfer member 92SC overlaps with the electronic component 10JE when viewed from the Z direction. Another portion of the heat transfer member 92SB overlaps with the connecting component 20 that connects the electronic component 10JE and the busbar 42JF when viewed from the Z direction.

[0129] (Heat transfer component 92SD) The heat transfer member 92SD is positioned between the busbar 42JG and the flat portion 81 of the metal plate 80, and transfers heat from the busbar 42JG to the metal plate 80. For example, a portion of the heat transfer member 92SD overlaps with the electronic component 10JE when viewed from the Z direction. Another portion of the heat transfer member 92SD overlaps with the connecting component 20 that connects the electronic component 10JE and the busbar 42JG when viewed from the Z direction.

[0130] <6.3 Size of heat transfer components> Figure 19 is a bottom view illustrating the size and arrangement of the heat transfer member 92. For ease of explanation, the heat transfer member 92 is hatched in Figure 19. In this embodiment, the heat transfer member 92L is larger than the heat transfer member 92S. For example, the area of ​​the heat transfer member 92L when viewed from the Z direction is larger than that of the heat transfer member 92S.

[0131] (Dimensional relationship between heat transfer member 92LA and heat transfer member 92SA) In this embodiment, the heat transfer member 92LA is larger than the heat transfer member 92SA. For example, the area of ​​the heat transfer member 92LA when viewed from the Z direction is larger than that of the heat transfer member 92SA. For example, the longitudinal direction of the heat transfer member 92SA coincides with the extension direction (e.g., X direction) of the busbar 42JA. The heat transfer member 92SA is positioned along the busbar 42JA and has a first length L21 in the extension direction (e.g., X direction) of the busbar 42JA. On the other hand, the longitudinal direction of the heat transfer member 92LA coincides with the extension direction (e.g., X direction) of the busbar 42JC. The heat transfer member 92LA is positioned along the busbar 42JC and has a second length L22 in the extension direction (e.g., X direction) of the busbar 42JC. The second length L22 is larger than the first length L21. On the other hand, the width W22 in the Y direction of the heat transfer member 92LA is the same as, for example, the width W21 in the Y direction of the heat transfer member 92SA.

[0132] In this embodiment, the heat transfer member 92LA protrudes from the connecting component 20JB toward the electronic component 10JC with a protrusion amount L32 (see Figure 18). On the other hand, the heat transfer member 92SA does not protrude toward the electronic component 10JB toward the connecting component 20JA, or protrudes with a protrusion amount L31 that is smaller than the protrusion amount L32 (see Figure 18). The protrusion amount L31 is an example of the "first protrusion amount". The protrusion amount L32 is an example of the "second protrusion amount".

[0133] In this embodiment, the busbar 42JC extends from the connecting component 20JB toward the electronic component 10JC through the space between the electronic component 10JA and the metal plate 80. For example, the heat transfer member 92LA includes a portion that extends beyond the +X-side end of the electronic component 10A and a portion that extends beyond the -X-side end of the electronic component 10A. On the other hand, the heat transfer member 92SA has a portion that extends beyond the +X-side end of the electronic component 10A, but does not have a portion that extends beyond the -X-side end of the electronic component 10A.

[0134] In this embodiment, the heat transfer member 92LA includes a first portion 92LAa and a second portion 92LAb. The first portion 92LAa overlaps with the electronic component 10JA when viewed from the Z direction. The second portion 92LAb extends from the first portion 92LAa toward the electronic component 10JC. The second portion 92LAb does not overlap with the electronic component 10JA when viewed from the Z direction.

[0135] (Dimensional relationship between heat transfer member 92LB and heat transfer member 92SB) In this embodiment, the heat transfer member 92LB is larger than the heat transfer member 92SB. For example, the area of ​​the heat transfer member 92LB when viewed from the Z direction is larger than that of the heat transfer member 92SB. For example, the heat transfer member 92SB is arranged along the bus bar 42JF and has a third length L23 in the direction of extension of the bus bar 42JF (e.g., the X direction). The heat transfer member 92LB is arranged along the bus bar 42JE and has a fourth length L24 in the direction of extension of the bus bar 42JE (e.g., the X direction). The fourth length L24 is larger than the third length L23. On the other hand, the width W24 of the heat transfer member 92LB in the Y direction is the same as, for example, the width W23 of the heat transfer member 92SB in the Y direction.

[0136] The above describes an example where the component to be connected is electronic component 10JB (second electronic component). However, the component to be connected may be an external connection component 30 instead of electronic component 10JB. For example, in the example shown in Figure 12, electronic component 10A is an example of a "first electronic component". Busbar 42B is an example of a "first busbar". External connection component 30A (see Figure 10) is an example of a "component to be connected". Busbar 42A is an example of a "second busbar". The second connection portion 62 of busbar 42A is electrically connected to electronic component 10 which generates more heat than electronic component 10A. The electronic component 10 electrically connected to the second connection portion 62 of busbar 42A is an example of a "third electronic component".

[0137] <7. Fixed structure> Next, we will explain the fixing structure of the subunit SU.

[0138] <7.1 Structure of the metal plate> Figure 20 is a cross-sectional view of the structure shown in Figure 10 along the line F20-F20. The metal plate 80 has a fixing portion 82 and a fixing portion 83, as described above.

[0139] The fixing portion 82 is a boss that protrudes in the +Z direction from the flat portion 81 of the metal plate 80. The fixing portion 82 protrudes, for example, beyond the first surface 51a of the flat portion 51 of the base plate 41 in the +Z direction. In this embodiment, the fixing portion 82 protrudes more significantly in the +Z direction than the fixing portion 83 which will be described later. The fixing portion 82 faces the fixing portion 52 of the base plate 41 in the Z direction. The fixing portion 82 has an engagement hole 82h that opens in the +Z direction. The inner circumferential surface of the engagement hole 82h has a screw groove.

[0140] The fixing portion 83 is a boss that protrudes from the flat portion 81 in the +Z direction. The fixing portion 83 is inserted into a through hole 51h (described later) in the flat portion 51 of the base plate 41. The fixing portion 83 protrudes, for example, through the through hole 51h of the flat portion 51 to the same position as the first surface 51a of the flat portion 51, or to a position beyond the first surface 51a of the flat portion 51 (a position on the +Z side of the first surface 51a). In the Z direction, the fixing portion 83 faces the mounting portion 14 of the electronic component 10. The fixing portion 83 has an engagement hole 83h that opens in the +Z direction. The inner circumferential surface of the engagement hole 83h has a screw groove.

[0141] A fastening member 112 (for example, a screw or bolt) is passed through the mounting hole 14h of the mounting portion 14 of the electronic component 10 from the +Z direction side. When the fastening member 112 passed through the mounting hole 14h of the mounting portion 14 of the electronic component 10 engages with the engagement hole 83h of the fixing portion 83 of the metal plate 80, the electronic component 10 is fixed to the metal plate 80 without the base plate 41.

[0142] <7.2 Structure of the wiring substrate> The base plate 41 has a fixing portion 52 which is fixed to the fixing portion 82 of the metal plate 80. The fixing portion 52 has, for example, an upright plate portion 52a and a horizontal plate portion 52b.

[0143] The upright plate portion 52a stands upright from the edge of the flat portion 51 of the base plate 41 in the +Z direction. The upright plate portion 52a is a plate portion that is aligned along the Y and Z directions. The thickness direction of the upright plate portion 52a is the X direction.

[0144] The horizontal plate portion 52b extends horizontally from the +Z end of the upright plate portion 52a. The horizontal plate portion 52b is a plate portion that lies along the horizontal direction. The horizontal plate portion 52b faces the fixing portion 82 of the metal plate 80 in the Z direction. The horizontal plate portion 52b has an insertion hole 52h that faces the engagement hole 82h of the fixing portion 82 of the metal plate 80. A fastening member 111 (e.g., a screw or bolt) is passed through the insertion hole 52h. When the fastening member 111 passed through the insertion hole 52h of the fixing portion 52 of the base plate 41 engages with the engagement hole 82h of the fixing portion 82 of the metal plate 80, the base plate 41 is fixed to the metal plate 80.

[0145] Furthermore, the flat portion 51 of the base plate 41 has the through hole 51h described above. The through hole 51h penetrates the flat portion 51 in the Z direction. When viewed from the Z direction, the through hole 51h is located at a position corresponding to the fixing portion 83 of the metal plate 80. The fixing portion 83 of the metal plate 80 protrudes through the through hole 51h of the base plate 41 to the same position as the first surface 51a of the flat portion 51, or to the +Z direction side of the first surface 51a of the flat portion 51. The mounting portion 14 of the electronic component 10 is fixed to the fixing portion 83 at the same position as the first surface 51a of the flat portion 51, or to the +Z direction side of the first surface 51a of the flat portion 51.

[0146] <8. Advantages> As a comparative example, consider a configuration in which all heat transfer members 92 are the same size. In this comparative example configuration, the size of the heat transfer members 92 is the same in areas with high thermal interference and areas with low thermal interference, so there may be room for improvement in heat dissipation. For example, heat may be transferred to the first electronic component from the connected component via the first busbar, and also from the third electronic component via the second busbar. In this case, if the heat generation of the third electronic component is greater than that of the connected component, a lot of heat will be transferred to the first electronic component from the third electronic component via the second busbar (the thermal interference will increase). If a lot of heat is transferred to the first electronic component from the third electronic component, it may become difficult to improve the heat dissipation of the electrical connection unit 1.

[0147] Therefore, in this embodiment, the electrical connection unit 1 includes a first electronic component (e.g., electronic component 10JA or electronic component 10A), a component to be connected, which is a second electronic component (e.g., electronic component 10JB) or a connection component for external connection (e.g., connection component 30A), a third electronic component (e.g., electronic component 10JC or another electronic component 10), a first busbar (e.g., busbar 42JA or busbar 42B), a second busbar (e.g., busbar 42JC or busbar 42A), a heat dissipation member (e.g., metal plate 80), a first heat transfer member (e.g., heat transfer member 92S), and a second heat transfer member (e.g., heat transfer member 92L). The third electronic component generates more heat than the component to be connected. The first busbar electrically connects the first terminal of the first electronic component to the component to be connected. The second busbar electrically connects the second terminal of the first electronic component to the third electronic component. The heat dissipation member faces the first busbar and the second busbar. The first heat transfer member is positioned between the first busbar and the heat dissipation member. The second heat transfer member is positioned between the second busbar and the heat dissipation member and is larger than the first heat transfer member.

[0148] With this configuration, even if the heat generated by the third electronic component is greater than that of the connected component, some of the heat that would otherwise be transferred from the third electronic component to the first electronic component via the second busbar can be transferred to the heat dissipation member by the second heat transfer member. This heat transfer suppresses the transfer of a large amount of heat from the third electronic component to the first electronic component via the second busbar (which would increase thermal interference). This allows for a balance in heat dissipation between areas with high and low thermal interference, thereby improving the heat dissipation performance of the electrical connection unit 1.

[0149] In this embodiment, the second heat transfer member has a larger area when viewed from the Z direction compared to the first heat transfer member. With this configuration, a portion of the heat moving from the third electronic component to the first electronic component via the second busbar can be more effectively transferred by the second heat transfer member to the heat dissipation member. This makes it possible to further improve the heat dissipation performance of the electrical connection unit 1.

[0150] In this embodiment, the component to be connected is, for example, a second electronic component. The third electronic component generates more heat than the second electronic component. With this configuration, the heat transfer from multiple electronic components (second and third electronic components) to the first electronic component can be balanced in terms of heat dissipation according to the magnitude of thermal interference. This makes it possible to further improve the heat dissipation performance of the electrical connection unit 1.

[0151] In this embodiment, the first heat transfer member is arranged along the first busbar and has a first length L31 in the direction of extension of the first busbar. The second heat transfer member is arranged along the second busbar and has a second length L32 in the direction of extension of the second busbar. The second length L32 is greater than the first length L31. With this configuration, since the first heat transfer member is arranged along the first busbar and the second heat transfer member is arranged along the second busbar, the heat dissipation from the first busbar and the second busbar to the heat dissipation member can be improved. Furthermore, while realizing such a structure, if the second length L32 is greater than the first length L31, it becomes easier for the second heat transfer member to more effectively transfer a portion of the heat moving from the third electronic component to the first electronic component via the second busbar to the heat dissipation member. This makes it possible to further improve the heat dissipation of the electrical connection unit 1.

[0152] In this embodiment, the electrical connection unit 1 further comprises a first connecting component that connects the first terminal of the first electronic component to the first busbar, and a second connecting component that connects the second terminal of the first electronic component to the second busbar. The second heat transfer member protrudes from the second connecting component toward the third electronic component by an amount L32. The first heat transfer member does not protrude toward the second electronic component toward the first connecting component, or protrudes by an amount L31 smaller than the amount L32. With this configuration, it becomes easier to move a portion of the heat moving from the third electronic component toward the first electronic component via the second busbar toward the heat dissipation member at a position in front of the first electronic component (a position toward the third electronic component). This makes it possible to further improve the heat dissipation performance of the electrical connection unit 1.

[0153] In this embodiment, the second busbar extends from the first electronic component to the third electronic component, passing between the first electronic component and the heat dissipation member. The second heat transfer member includes a first portion 92La that overlaps with the first electronic component, and a second portion and 92Lb that extend from the first portion 92La toward the third electronic component. With this configuration, it becomes easier to effectively transfer a portion of the heat moving from the third electronic component to the first electronic component via the second busbar toward the heat dissipation member as early as possible. This further improves the heat dissipation performance of the electrical connection unit 1.

[0154] <9. Variation> Next, we will describe some variations. Note that, apart from the configurations described below, the configurations in each variation are the same as those of the first embodiment.

[0155] (First variation) The routing substrate 40 is not limited to a structure in which the base plate 41 and the busbar 42 are integrated by insert molding. For example, the base plate 41, which is provided with a housing portion 55 for housing the busbar 42, may be molded, and then the busbar 42 may be placed in the housing portion 55. In this case, the busbar 42 may be fixed to the housing portion 55 by fitting, or by adhesive or other fastening means. In these cases, potting may be applied to fill the gap between the busbar 42 and the housing portion 55.

[0156] (Second variation) The base member of the routing substrate 40 is not limited to a base plate 41 having a plate-shaped flat portion 51. The routing substrate 40 may also be a base member having a sheet-shaped flat portion 51 (for example, an insulating sheet). In this case, a portion of the flat portion 51 may conform to the outer shape of the bus bar 42 to form the housing portion 55. In this disclosure, "sheet-shaped" or "sheet" is not limited to a member with a thickness of 1 mm or more, and may also include a member with a thickness of less than 1 mm (so-called film).

[0157] (Third variation) The base plate 41 of the cable routing substrate 40 may include a plurality of members (plate members or sheet members). The plurality of members are provided so as to sandwich a plurality of bus bars 42 arranged in the horizontal direction. For example, the plurality of members may be integrated by sandwiching a plurality of bus bars 42, for example, by lamination molding. The plurality of members form a planar portion 51. In this case, the housing 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 members may be, for example, flexible sheet members. 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.

[0158] (Fourth variation) The connection between the electronic component 10 and the busbar 42 is not limited to a connection via the connecting component 20. The electronic component 10 may be directly connected to the busbar 42 using fastening members (e.g., bolts or screws) or welding.

[0159] (Second Embodiment) Next, a second embodiment will be described. The second embodiment differs from the first embodiment in that it is provided with a holding portion 131 that supports the busbar 42 in contact with the heat transfer member 92L. Other than what is described below, the configuration is the same as that of the first embodiment.

[0160] Figure 21 is a plan view illustrating the electrical connection unit 1 of the second embodiment. In the second embodiment, the base plate 41 has a holding portion 131. When viewed from the Z direction, the holding portion 131 overlaps a part of the bus bar 42 that is in contact with the heat transfer member 92L from the +Z direction side, and supports the bus bar 42 with respect to the Z direction.

[0161] Figure 22 is a cross-sectional view of the electrical connection unit 1 shown in Figure 21 along the line F22-F22. The holding portion 131 is, for example, positioned adjacent to the first surface 51a of the planar portion 51 and above the busbar 42, supporting the busbar 42 from above. The holding portion 131 holds the busbar 42, for example, to prevent it from falling upward. The holding portion 131 may be positioned to overlap with the heat transfer member 92L when viewed from the Z direction, or it may be positioned away from the heat transfer member 92L.

[0162] With this configuration, even if the elastic force of the large heat transfer member 92L acts on the busbar 42 in an upward direction that causes it to detach, the busbar 42 is less likely to detach from the base plate 41.

[0163] The retaining portion 131 may be formed, for example, by insert molding, similar to the other parts of the flat portion 51. Alternatively, the retaining portion 131 may be formed by a separate component that is provided separately from the base plate 41 and then attached to the base plate 41.

[0164] Several embodiments and modifications have been described above. However, the embodiments and modifications are not limited to the examples described above. For example, multiple embodiments may be implemented in combination with each other. [Explanation of symbols]

[0165] 1…Electrical connection unit SU... Subunit 10…Electronic components 10A…Electronic component (First electronic component) 10JA…Electronic components (First Electronic Components) 10JB…Electronic component (second electronic component, component to be connected) 10JC…Electronic components (Third-class electronic components) Terminals 13, 13A, 13B… 20…Connecting parts 20JA…First connecting component 20JB…Second connecting part 21…Part 1 22…Second part 30…Connecting parts (parts to be connected) 31…Part 1 32…Second part 40… Circuit board for cable routing 41…Base plate 42... Bus bar 42A…Bus bar (second bus bar) 42B... Bus bar (1st bus bar) 42JA... Bus bar (1st bus bar) 42JC... Bus bar (2nd bus bar) 55...Detention Unit 80…Metal plate (heat dissipation component) 81...Plane part 82…Fixed part 83…Fixed part 92… Heat transfer components 92S, 92SA… Heat transfer component (first heat transfer component) 92L, 92LA… Heat transfer components (second heat transfer component) 92La…Part 1 92Lb…Second part

Claims

1. A first electronic component having a first terminal and a second terminal, The component to be connected is a second electronic component or an external connection component, A third electronic component that generates more heat than the aforementioned connected component, A first busbar electrically connects the first terminal of the first electronic component to the component to be connected, A second busbar electrically connects the second terminal of the first electronic component and the third electronic component, A heat dissipation member facing the first busbar and the second busbar, A first heat transfer member is disposed between the first busbar and the heat dissipation member, A second heat transfer member is positioned between the second busbar and the heat dissipation member and is larger than the first heat transfer member, An electrical connection unit equipped with [a specific feature].

2. When the direction from the first busbar and the second busbar toward the heat dissipation member is defined as the first direction, the second heat transfer member has a larger area when viewed from the first direction compared to the first heat transfer member. The electrical connection unit according to claim 1.

3. The component to be connected is the second electronic component, The third electronic component generates more heat than the second electronic component. The electrical connection unit according to claim 1 or claim 2.

4. The first heat transfer member is arranged along the first busbar and has a first length in the direction of extension of the first busbar. The second heat transfer member is arranged along the second busbar and has a second length in the direction of extension of the second busbar. The second length is greater than the first length. The electrical connection unit according to claim 1 or claim 2.

5. A first connecting component that connects the first terminal of the first electronic component to the first busbar, A second connecting component that connects the second terminal of the first electronic component and the second busbar, Furthermore, The second heat transfer member protrudes from the second connecting component toward the third electronic component by a second amount. The first heat transfer member does not protrude toward the second electronic component relative to the first connecting component, or protrudes by a first protrusion amount smaller than the second protrusion amount. The electrical connection unit according to claim 1 or claim 2.

6. The second busbar extends from the first electronic component to the third electronic component, passing between the first electronic component and the heat dissipation member. When the direction from the first busbar and the second busbar toward the heat dissipation member is defined as the first direction, the second heat transfer member includes a first portion that overlaps with the first electronic component and a second portion that extends from the first portion toward the third electronic component. The electrical connection unit according to claim 1 or claim 2.

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