ELECTRICAL CONNECTION UNIT

An electrical connection unit includes a first electronic component, an insulating base member, and a first bus bar. The base member includes a plate-shaped or sheet-shaped flat surface portion having a first surface facing the first electronic component. In a case where a thickness direction of the flat surface portion is a first direction, the flat surface portion includes a first accommodation portion that is recessed in the first direction or penetrates the flat surface portion in the first direction. The first bus bar has a first connection portion electrically connected to the first electronic component, and at least part of the first bus bar is accommodated in the first accommodation portion and extends along the flat surface portion. At least the first connection portion of the first bus bar protrudes from the first surface to outside of the first accommodation portion in the first direction.

BACKGROUND OF THE INVENTION

Field of the Invention

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

Priority is claimed on Japanese Patent Application No. 2024-087285 filed in Japan on May 29, 2024, the content of which is incorporated herein by reference.

Description of the Related Art

An electrical connection unit having a housing that accommodates electronic components and a bus bar attached to the housing in a standing posture is known.

SUMMARY OF THE INVENTION

Incidentally, a height of an electrical connection unit is expected to be further reduced.

An embodiment provides an electrical connection unit capable of achieving height reduction.

An electrical connection unit according to an embodiment includes a first electronic component, an insulating base member, and a first bus bar. The base member includes a plate-shaped or sheet-shaped flat surface portion having a first surface facing the first electronic component. In a case where a thickness direction of the flat surface portion is a first direction, the flat surface portion includes a first accommodation portion that is recessed in the first direction or penetrates the flat surface portion in the first direction. The first bus bar has a first connection portion electrically connected to the first electronic component, and at least part of the first bus bar is accommodated in the first accommodation portion and extends along the flat surface portion. At least the first connection portion of the first bus bar protrudes from the first surface to outside of the first accommodation portion in the first direction.

According to one embodiment, a height of an electrical connection unit can be reduced.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments will be described with reference to the drawings. In the following description, constitutions having the same or similar functions are denoted by the same reference numbers. Redundant descriptions of these constitutions may be omitted. Note that the constitution described below does not limit the scope of the embodiment.

In the present disclosure, the terms are defined as follows. The term “connection” is not limited to a mechanical connection, and may include an electrical connection. That is, the term “connection” is not limited to a case where two elements that are connection targets are directly connected, and may include a case where two elements that are connection targets are connected with another element interposed therebetween. The term “accommodation” is not limited to a case where the entire component is accommodated, and may include a case where only part of the component is accommodated (a state in which the remaining part of the component protrudes). The term “facing” indicates that virtual projection images of two target objects overlap each other when viewed from a specific direction. That is, the term “facing” is not limited to a case where two target objects directly face each other, and may include a case where two target objects face each other in a state in which another member exists between the two target objects. “Parallel”, “orthogonal”, or “the same” may include “substantially parallel”, “substantially orthogonal”, or “substantially the same”, respectively.

In the present disclosure, a +X direction, a −X direction, a +Y direction, a −Y direction, a +Z direction, and a −Z direction are defined as follows. The +X direction is a direction from a first end 801e to a second end 80e2 of a metal plate 80 that will be described later (see FIG. 11). The −X direction is a direction opposite to the +X direction. Hereinafter, in a case where the +X direction and the −X direction are not distinguished, the directions will be simply referred to as “X direction”. The +Y direction and the −Y direction are directions intersecting (for example, orthogonal to) the X direction. The +Y direction is a direction from a third end 80e3 to a fourth end 80e4 of the metal plate 80 that will be described later (see FIG. 11). The −Y direction is a direction opposite to the +Y direction. Hereinafter, in a case where the +Y direction and the −Y direction are not distinguished, the directions will be simply referred to as “Y direction”. The +Z direction and the −Z direction are directions intersecting (for example, orthogonal to) the X direction and the Y direction. The +Z direction is a direction from the metal plate 80 that will be described later toward a main body MU (see FIG. 1). The −Z direction is a direction opposite to the +Z direction. Hereinafter, in a case where the +Z direction and the −Z direction are not distinguished, the directions will be simply referred to as “Z direction”. The Z direction is an example of a “first direction”. The X direction is an example of a “second direction”. The “second direction” is not limited to the X direction, and may be the Y direction or other directions.

Hereinafter, in a case where the X direction and the Y direction are not distinguished, the directions may be referred to as “horizontal direction”. Hereinafter, the Z direction may be referred to as “vertical direction”. Hereinafter, the +Z direction side may be referred to as “upper”, and the −Z direction side may be referred to as “lower”. However, these expressions are expressions for convenience of description, and do not limit a gravity direction of an electrical connection unit 1 (an installation posture of the electrical connection unit 1).

First Embodiment

1. Constitution of Electrical Connection Unit

FIG. 1 is a cross-sectional view illustrating an electrical connection unit 1 of a first embodiment. The electrical connection unit 1 is, for example, an in-vehicle device mounted on a vehicle such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV). The electrical connection unit 1 may be referred to as an “electrical connection box” or a “junction box”, for example. However, the electrical connection unit 1 is not limited to a box-shaped device.

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

2. Main Body

First, the main body MU will be described.

FIG. 2 is a perspective view for describing the main body MU. The main body MU is a portion that performs a main function (for example, switching of electrical connection states or overcurrent protection) of the electrical connection unit 1. In the present 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 the present embodiment, the main body MU includes three subunits SU (SUX, SUY, SUZ). Each subunit SU may be referred to as a “circuit constitution body”.

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

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

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

In the present embodiment, the three subunits SUX, SUY, and SUZ are disposed to be arranged in the X direction. For example, the subunit SUX is disposed on the +X direction side with respect to the subunit SUY. The subunit SUX and the subunit SUY are electrically connected via a plurality of coupling bus bars 75 extending between the first routing board 40X and the second routing board 40Y. On the other hand, the subunit SUZ is disposed on the −X direction side with respect to the subunit SUY. The subunit SUZ and the subunit SUY are electrically connected via a plurality of coupling bus bars 75 (only one is illustrated in FIG. 2) extending between the third routing board 40Z and the second routing board 40Y. The coupling bus bar 75 is disposed on the side opposite to the metal plate 80 with respect to the plurality of subunits SU.

In the present embodiment, the three routing boards 40X, 40Y, and 40Z included in the three subunits SUX, SUY, and SUZ are disposed on the same plane. In other words, the three routing boards 40X, 40Y, and 40Z are disposed at the same height position in the Z direction. As a result, one large routing board 40M is formed by the three routing boards 40X, 40Y, and 40Z.

In the present embodiment, the three subunits SUX, SUY, and SUZ have the same or similar basic structure. Therefore, one subunit SU will be described in detail below as a representative. Hereinafter, in a case where the subunit SUX, the subunit SUY, and the subunit SUZ are not distinguished, the subunits are simply referred to as “subunit SU”. In addition, in a case where the electronic component 10X, the electronic component 10Y, and the electronic component 10Z are not distinguished, the electronic components are simply referred to as “electronic component 10”. In a case where the first routing board 40X, the second routing board 40Y, and the third routing board 40Z are not distinguished, the routing boards are simply referred to as “routing board 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”.

Note that the main body MU need not be divided into a plurality of subunits SU instead of the example described above. That is, the main body MU may be formed by the plurality of electronic components 10 and one routing board 40. In addition, the two or more subunits SU are not limited to the subunits SU having different functions, and may be the subunits SU having the same function.

3. Constitution of Subunit

Next, a constitution of the subunit SU will be described.

FIG. 3 is a perspective view for describing the subunit SU. FIG. 4 is a partially exploded perspective view of the subunit SU. The subunit SU includes, for example, a plurality of electronic components 10, a plurality of connection components 20 for component connection, a plurality of connection components 30 for external connection, and a routing board 40. The connection components 20 and 30 are members forming an energization path in the vertical direction. The connection components 20 and 30 may be referred to as “vertical routing members”.

<3.1 Electronic Component and Connection Component for Component Connection>

First, the electronic component 10 and the connection component 20 for component connection will be described.

The electronic component 10 is an electronic component mounted according to a function required for the subunit SU. The electronic component 10 is, for example, a connector, a fuse, a relay (for example, a mechanical relay or a semiconductor relay), a capacitor, a branch component, any of various sensors (for example, a current sensor or a voltage sensor), an electronic control unit, or an electronic component unit in which two or more of these are unitized. Note that the type of the electronic component 10 is not limited to the above example. The electronic component 10 is, for example, a heat generating component that generates heat at the time of energization. Hereinafter, a first-type electronic component 10M and a second-type electronic component 10N will be described as examples of the electronic component 10.

The connection component 20 is a component that electrically connects the electronic component 10 to the routing board 40. The connection component 20 forms part of an energization path in the subunit SU. The connection component 20 is made of a metal (for example, copper or a copper alloy). The connection component 20 may be referred to as a “metal component”. Hereinafter, a first-type connection component 20M and a second-type connection component 20N will be described as examples of the connection component 20.

FIG. 5 is a perspective view illustrating the first-type electronic component 10M and the first-type connection component 20M. The first-type electronic component 10M is an electronic component in which a plurality of terminals 13 are disposed to be arranged at one end of the electronic component 10M. The electronic component 10M includes, for example, a case 11, a component body 12, a plurality of terminals 13, and a plurality of attachment portions 14.

The case 11 is an outer member that forms most of the outer shape of the electronic component 10M. The case 11 is made of, for example, synthetic resin and has an insulating property. The case 11 accommodates the component body 12. The case 11 and the component body 12 may be integrally formed.

In the present embodiment, the case 11 has an insulating rib 11a that protrudes in the horizontal direction (for example, the X direction) and extends in the Z direction. The insulating rib 11a has, for example, a plate shape formed in the horizontal direction (for example, the X direction) and the Z direction. The insulating rib 11a extends over the entire length of the case 11 in the Z direction, for example. The insulating rib 11a is disposed between the plurality of terminals 13 (a terminal 13A and a terminal 13B that will be described later). The insulating rib 11a electrically insulates the terminal 13A from the terminal 13B. In the present embodiment, part of the insulating rib 11a is disposed between first portions 21 (that will be described later) of two connection components 20M connected to the electronic component 10M. The insulating rib 11a electrically insulates the first portions 21 of the two connection components 20M connected to the electronic component 10M from each other.

The component body 12 is a portion that performs a main function of the electronic component 10M. For example, in a case where the electronic component 10M is a relay, the component body 12 includes a switch (for example, a contact) that switches between a conductive state and a non-conductive state. For example, in a case where the electronic component 10M is a fuse, the component body 12 includes a fusion portion that is fused when an overcurrent flows. For example, in a case where the electronic component 10M is a capacitor, the component body 12 includes a portion that stores electric charge.

The terminal 13 is an electrical connection portion exposed to the outside of the case 11. The terminal 13 is electrically connected to the component body 12 inside the case 11. In the present embodiment, the electronic component 10M includes a terminal 13A and a terminal 13B as the plurality of terminals 13. One of the terminal 13A and the terminal 13B is a terminal on the positive electrode side. The other of the terminal 13A and the terminal 13B is a terminal on the negative electrode side. One of the terminal 13A and the terminal 13B is an example of a “first terminal”. The other of the terminal 13A and the terminal 13B is an example of a “second terminal”.

In the present embodiment, the terminal 13A and the terminal 13B are provided at one end of the electronic component 10M in the horizontal direction (for example, the X direction). The terminal 13A and the terminal 13B are disposed to be arranged in the horizontal direction (for example, the Y direction). Each terminal 13 has an attachment hole 13h to which a fastening member 71 (for example, a screw or a bolt) that will be described later is attached. The attachment hole 13h is open in the horizontal direction (for example, the X direction). An inner circumferential surface of the attachment hole 13h of the electronic component 10M has a screw groove.

The attachment portion 14 is a portion for fixing the electronic component 10M. The attachment portion 14 has an attachment hole 14h to which a fastening member 112 (for example, a screw or a bolt; and see FIG. 11) that will be described later is attached. The attachment hole 14h is open in the Z direction. The attachment hole 14h is an insertion hole through which the fastening member 112 passes. A fixing destination of the attachment portion 14 will be described later.

The first-type connection component 20M is a component that electrically connects the first-type electronic component 10M to the routing board 40. In the present embodiment, the connection component 20M electrically connects the electronic component 10M to a bus bar 42 (see FIG. 8) included in the routing board 40. In the present embodiment, a width L12 of the connection component 20M in a longitudinal direction (for example, the X direction) of the electronic component 10M is smaller than a width L11 of the electronic component 10M in the longitudinal direction. The connection component 20M includes, for example, a first portion 21 and a second portion 22.

The first portion 21 of the connection component 20M is a portion connected to the terminal 13 of the electronic component 10M. The first portion 21 is a plate-shaped or rectangular parallelepiped portion extending in the Z direction. The first portion 21 extends in the Z direction along one end (for example, an end in the X direction) of the electronic component 10M. The first portion 21 is a standing portion that stands in the Z direction with respect to the routing board 40 (for example, with respect to a bus bar 42 that will be 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).

The first portion 21 of the connection component 20M has a first attachment hole 21h through which the fastening member 71 (for example, a screw or a bolt) passes. The first attachment hole 21h is open in the horizontal direction (for example, the X direction). The first portion 21 has a recess 25 around the first attachment hole 21h. The recess 25 is an accommodation portion that accommodates a head of the fastening member 71 inserted into the first attachment hole 21h. The fastening member 71 that has passed through the first attachment hole 21h is engaged with the attachment hole 13h of the terminal 13 of the electronic component 10M, and thus the first portion 21 is physically and electrically connected to the terminal 13 of the electronic component 10M. The first portion 21 need not have the recess 25.

The second portion 22 of the connection component 20M is a portion connected to the bus bar 42 (see FIG. 8). The second portion 22 protrudes in the horizontal direction (for example, the X direction) from end of the first portion 21 on the −Z direction side. The second portion 22 is a plate portion provided in the horizontal direction. The second portion 22 is adjacent to the bus bar 42 in the Z direction, and is connected to the bus bar 42 from the Z direction. The second portion 22 of the connection component 20M is attached to the fastening member 43 (for example, a screw or a bolt; and see FIG. 8) protruding from the bus bar 42 in the +Z direction from the Z direction, and is physically and electrically connected to the bus bar 42. In the present embodiment, the second portion 22 of the connection component 20M has a second attachment hole 22h through which the fastening member 43 passes. The second attachment hole 22h is open in the Z direction. In the second portion 22, the fastening member 43 passes through the second attachment hole 22h. An engagement member 44 (for example, a nut; and see FIG. 3) is engaged with the tip of the fastening member 43 that has passed through the second attachment hole 22h, and thus the second portion 22 is fixed to the bus bar 42. In the present embodiment, the first portion 21 and the second portion 22 form one L-shaped connection component 20M.

FIG. 6 is a perspective view illustrating the second-type electronic component 10N and the second-type connection component 20N. The second-type electronic component 10N is an electronic component in which two terminals 13 are separately disposed at both ends in the horizontal direction of the electronic component 10N. The electronic component 10N includes, for example, a case 11, a component body 12, and a plurality of terminals 13. Note that, among the constitutions of the electronic component 10N, constitutions having functions similar to those of the electronic component 10M are denoted by the same reference numbers. In this case, in the description regarding the electronic component 10N, the “electronic component 10M” may be replaced with the “electronic component 10N” in the description regarding the electronic component 10M described above.

In the electronic component 10N, the terminal 13A and the terminal 13B are disposed separately at both ends of the electronic component 10N in the horizontal direction (for example, the X direction). Each terminal 13 has an attachment hole 13h to which a fastening member 72 (for example, a screw or a bolt) that will be described later is attached. The attachment hole 13h is open in the Z direction. For example, the attachment hole 13h of the electronic component 10N is an insertion hole through which the fastening member 72 passes. One of the terminal 13A and the terminal 13B is an example of a “first terminal”. The other of the terminal 13A and the terminal 13B is an example of a “second terminal”.

The second-type connection component 20N is a component that electrically connects the second-type electronic component 10N to the routing board 40. In the present embodiment, the connection component 20N electrically connects the electronic component 10N to the bus bar 42 (see FIG. 8) included in the routing board 40. In the present embodiment, a width L12 of the connection component 20N in the longitudinal direction (for example, the X direction) of the electronic component 10N is smaller than a width L11 of the electronic component 10N in the longitudinal direction. The connection component 20N includes, for example, a first portion 21, a second portion 22, and a third portion 23.

The first portion 21 of the connection component 20N is a portion connected to the terminal 13 of the electronic component 10N. The first portion 21 is a rectangular parallelepiped portion extending in the Z direction. The first portion 21 is a standing portion that stands in the Z direction with respect to the routing board 40 (for example, with respect 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 is connected to the terminal 13 of the electronic component 10N from the Z direction. The first portion 21 of the connection component 20N has a first attachment hole 21h with which the fastening member 72 is engaged. The first attachment hole 21h is open in the Z direction. An inner circumferential surface of the first attachment hole 21h of the connection component 20N has a screw groove. The fastening member 72 that has passed through the attachment hole 13h of the terminal 13 of the electronic component 10N is engaged with the attachment hole 21h of the first portion 21, and thus the first portion 21 is physically and electrically connected to the terminal 13 of the electronic component 10N.

The second portion 22 of the connection component 20N is a portion connected to the bus bar 42 (see FIG. 8). The second portion 22 protrudes in the horizontal direction (for example, the X direction) from end of the first portion 21 on the −Z direction side. The second portion 22 is a plate portion provided in the horizontal direction. The second portion 22 is adjacent to the bus bar 42 in the Z direction, and is connected to the bus bar 42 from the Z direction. The second portion 22 of the connection component 20N is attached to, from the Z direction, the fastening member 43 (for example, a screw or a bolt; and see FIG. 8) protruding from the bus bar 42 in the +Z direction, and is physically and electrically connected to the bus bar 42. In the present embodiment, the second portion 22 of the connection component 20N has a second attachment hole 22h through which the fastening member 43 passes. The second attachment hole 22h is open in the Z direction. In the second portion 22, the fastening member 43 that will be described later passes through the second attachment hole 22h.

An engagement member 44 (for example, a nut; and see FIG. 3) is engaged with the tip of the fastening member 43 that has passed through the second attachment hole 22h, and thus the second portion 22 is fixed to the bus bar 42.

The third portion 23 is a standing wall (side wall) standing in the +Z direction from both ends of the second portion 22 in the horizontal direction. The third portion 23 is a wall provided in the Z direction. The third portion 23 is connected to the first portion 21 and is also connected to the second portion 22. For example, the third portion 23 extends obliquely so as to increase in the X direction as proceeding in the −Z direction. The third portion 23 may be provided in the connection component 20M described above. On the other hand, the connection component 20N need not have the third portion 23.

<3.2 Connection Component for External Connection>

Next, the connection component 30 for external connection will be described.

FIG. 7 is a perspective view illustrating the connection component 30 for external connection. The connection component 30 is a component that electrically connects an external connection bus bar 76 to the routing board 40. In the present embodiment, the connection component 30 electrically connects the external connection bus bar 76 to the bus bar 42 (see FIG. 8) included in the routing board 40. The external connection bus bar 76 is electrically connected to an external device. In the present disclosure, the “external device” is an electrical device existing outside the electrical connection unit 1. The external device is, for example, a battery unit mounted on a vehicle or an inverter for driving a motor of the vehicle, but is not limited to these examples. The connection component 30 includes, for example, a first portion 31, a second portion 32, and a third portion 33.

The first portion 31 is a portion connected to the external connection bus bar 76. The first portion 31 is a rectangular parallelepiped portion extending in the Z direction. The first portion 31 is a standing portion that stands in the Z direction with respect to the routing board 40 (for example, with respect to the bus bar 42). The first portion 31 is adjacent to the external connection bus bar 76 in the Z direction, and is connected to the external connection bus bar 76 from the Z direction. The first portion 31 has a first attachment hole 31h through which a fastening member 73 (for example, a screw or a bolt) passes. The first attachment hole 31h is open in the Z direction. An inner circumferential surface of the first attachment hole 31h has a screw groove. The fastening member 73 that has passed through the attachment hole 76h of the external connection bus bar 76 is engaged with the attachment hole 31h of the first portion 31, and thus the first portion 31 is physically and electrically connected to the external connection bus bar 76.

The second portion 32 is a portion connected to the bus bar 42 (see FIG. 8). The second portion 32 protrudes in the horizontal direction (for example, the X direction) from the end of the first portion 31 on the −Z direction side. The second portion 32 is a plate portion provided in the horizontal direction. The second portion 32 is adjacent to the bus bar 42 in the Z direction, and is connected to the bus bar 42 from the Z direction. The second portion 32 is attached to, from the Z direction, the fastening member 43 (for example, a screw or a bolt; and see FIG. 8) protruding from the bus bar 42 in the +Z direction, and is physically and electrically connected to the bus bar 42. In the present embodiment, the second portion 32 has a second attachment hole 32h through which the fastening member 43 passes. The second attachment hole 32h is open in the Z direction. In the second portion 32, the fastening member 43 that will be described later passes through the second attachment hole 32h. The engagement member 44 (for example, a nut; and see FIG. 3) is engaged with the tip of the fastening member 43 that has passed through the second attachment hole 32h, and thus the second portion 32 is fixed to the bus bar 42.

The third portion 33 is a standing wall (side wall) standing in the +Z direction from both ends of the second portion 32 in the horizontal direction. The third portion 33 is a wall provided in the Z direction. The third portion 33 is connected to the first portion 31 and is also connected to the second portion 32. For example, the third portion 33 extends obliquely to increase in the X direction (or the Y direction) as proceeding in the −Z direction. The connection component 30 need not include the third portion 33.

Next, the routing board 40 will be described.

FIG. 8 is a perspective view illustrating the routing board 40. The routing board is a member that forms at least part of an energization path between the plurality of electronic components 10 and/or at least part of an energization path between the electronic component 10 and an external device. In the present disclosure, the “routing board” indicates a board-type routing structure. The “board type” indicates a plate shape along one plane when viewed as a whole regardless of a fine shape. In the present disclosure, the term “plate shape”, “sheet shape”, or “planar” is not limited to the case of being completely flat, and may include a case where a fixing structure, a rib, or the like protruding in the Z direction is partially present, a case where an uneven shape following the thickness of the bus bar is present on the surface, and the like. In the present embodiment, the routing board 40 has a plate shape formed in the X direction and the Y direction.

The routing board 40 includes, for example, a base plate 41, one or more (for example, a plurality of) bus bars 42, and a plurality of fastening members 43. In the present embodiment, the base plate 41 and the plurality of bus bars 42 are integrated through insert molding. For example, the routing board 40 is formed as a single member by insert-molding the bus bar 42 with the base plate 41 after the fastening member 43 is fixed to the bus bar 42. That is, the bus bar 42 is integrated with the base plate 41 without using a fastening member such as a screw or a bolt. Note that the routing board may be formed by another structure instead of the insert molding. A modification example in which the routing board 40 is formed by another structure will be described later.

FIG. 9 is a partially exploded perspective view of the routing board 40. Hereinafter, for convenience of description, the base plate 41, the bus bar 42, and the fastening member 43 will be described with reference to the drawings in which the routing board 40 is partially exploded.

The base plate 41 is a holding member that integrally holds the plurality of bus bars 42 arranged in the horizontal direction at intervals. The base plate 41 is made of, for example, synthetic resin and has an insulating property. The base plate 41 electrically insulates the plurality of bus bars 42 from each other. The base plate 41 is an example of a “base member”. The base plate 41 may be referred to as an “insulating substrate”. The base plate 41 includes, for example, a flat surface portion 51 and a plurality of fixing portions 52. The fixing portion 52 will be described later.

The flat surface portion 51 is a portion formed in a plate shape in the base plate 41. The flat surface portion 51 has a plate shape formed in the horizontal direction. The flat surface portion 51 forms a main portion of the base plate 41. The flat surface portion 51 forms a base portion (insulating base portion) of the base plate 41. In the present embodiment, the flat surface portion 51 extends over the entire width in the X direction of the base plate 41 and over the entire width in the Y direction of the base plate 41 except for four corner portions of the base plate 41.

The flat surface portion 51 has a first surface 51a and a second surface 51b. The first surface 51a is a surface directed in the +Z direction. The first surface 51a is a flat surface provided in the horizontal direction. The first surface 51a faces the plurality of electronic components 10 and faces the insulating cover 93 (see FIG. 1) of the electrical connection unit 1. The second surface 51b is located on the side opposite to the first surface 51a. The second surface 51b is a surface directed in the −Z direction. The second surface 51b is a flat surface provided in the horizontal direction. The second surface 51b faces the metal plate 80 (see FIG. 1). A thickness direction (plate thickness direction) of the flat surface portion 51 is the Z direction.

The flat surface portion 51 has, for example, one or more (for example, a plurality of) accommodation portions 55 in which the bus bars 42 are accommodated, respectively. The plurality of accommodation portions 55 are formed apart from each other in the X direction or the Y direction. Each of the accommodation portions 55 is, for example, a through-hole penetrating the flat surface portion 51 in the Z direction. Note that the accommodation portion 55 may be a recess provided on the first surface 51a or the second surface 51b of the flat surface portion 51 and recessed in the Z direction, instead of a through-hole. In the present disclosure, the phrase “the accommodation portion penetrates the flat surface portion in the first direction (Z direction)” may include a case where part of the entire length of the accommodation portion 55 penetrates the flat surface portion 51 in the Z direction (for example, the remaining portion of the accommodation portion 55 may be a recess recessed in the Z direction, or may be provided inside the base plate 41 and not exposed to the outside of the base plate 41). Similarly, in the present disclosure, the phrase “the accommodation portion is recessed in the first direction (Z direction)” may include a case where part of the entire length of the accommodation portion 55 is recessed in the Z direction (for example, a remaining portion of the accommodation portion 55 may be a through-hole penetrating the flat surface portion 51 in the Z direction, or may be provided inside the base plate 41 and not exposed to the outside of the base plate 41).

Each accommodation portion 55 has an outer shape corresponding to the shape of the bus bar 42 to be accommodated when viewed from the Z direction. In the present embodiment, the flat surface portion 51 includes, for example, five accommodation portions 55A, 55B, 55C, 55D, and 55E as the plurality of accommodation portions 55. The accommodation portion 55A is provided to correspond to a bus bar 42A that will be described later, and accommodates the bus bar 42A. The accommodation portion 55B is provided to correspond to a bus bar 42B that will be described later, and accommodates the bus bar 42B. The accommodation portion 55C is provided to correspond to a bus bar 42C that will be described later, and accommodates the bus bar 42C. The accommodation portion 55D is provided to correspond to a bus bar 42D that will be described later, and accommodates the bus bar 42D. The accommodation portion 55E is provided to correspond to a bus bar 42E that will be described later, and accommodates the bus bar 42E.

The bus bar 42 is a routing member (electrical connection member) included in the routing board 40. The bus bar 42 is, for example, a routing member for electrically connecting the plurality of electronic components 10. Alternatively, the bus bar 42 may be a routing member for connecting the electronic component 10 to an external device. The bus bar 42 is made of a metal (for example, copper or a copper alloy) and has conductivity. In the present embodiment, the routing board 40 includes, for example, five bus bars 42A, 42B, 42C, 42D, and 42E as the plurality of bus bars 42. The five bus bars 42A, 42B, 42C, 42D, and 42E are disposed to be arranged in the horizontal direction at intervals. The five bus bars 42A, 42B, 42C, 42D, and 42E include portions arranged on the same plane. The five bus bars 42A, 42B, 42C, 42D, and 42E are held by the flat surface portion 51 of the base plate 41.

At least part of each bus bar 42 has a plate shape formed in the horizontal direction. At least part of each bus bar 42 is accommodated in the accommodation portion 55 and extends along the flat surface portion 51. That is, at least part of each bus bar 42 extends along the first surface 51a of the flat surface portion 51. At least part of each bus bar 42 extends in the horizontal direction in the accommodation portion 55. In the present embodiment, each bus bar 42 has a plate shape formed in the horizontal direction over the entire bus bar 42. Each of the bus bars 42 is accommodated in the accommodation portion 55 over the entire length of the bus bar 42 and extends along the flat surface portion 51. Hereinafter, a portion of each bus bar 42 that is accommodated in the accommodation portion 55 and extends along the flat surface portion 51 may be referred to as a “plate portion 42p”. The bus bar 42 is a member that forms a horizontal energization path. The bus bar 42 may be referred to as a “horizontal routing member”.

FIG. 10 is a plan view illustrating the routing board 40. The plate portion 42p of each bus bar 42 has, for example, a first connection portion 61, a second connection portion 62, and an extending portion 63.

The first connection portion 61 is a portion in contact with one connection component 20 (hereinafter referred to as a “first connection component 20”). The first connection component 20 is a connection component that connects one electronic component 10 (hereinafter referred to as a “first electronic component 10”) to the bus bar 42. The first connection portion 61 is a portion of the bus bar 42 overlapping 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.

The second connection portion 62 is a portion in contact with another connection component 20 (hereinafter referred to as a “second connection component 20”). The second connection component 20 is a connection component that connects another electronic component 10 (hereinafter referred to as a “second electronic component 10”) included in the plurality of electronic components 10 to the bus bar 42. The second connection portion 62 is a portion of the bus bar 42 overlapping 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.

Note that the second connection portion 62 may be a portion in contact with another connection component 30 (hereinafter referred to as a “second connection component 30”) instead of the above example. The connection component 30 is a connection component for connecting an external device to the bus bar 42. In this case, the second connection portion 62 is a portion of the bus bar 42 overlapping 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.

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

The extending portion 63 extends from the first connection portion 61 in the X direction or the Y direction. The extending portion 63 is provided between the first connection portion 61 and the second connection portion 62. The extending portion 63 extends over the first connection portion 61 and the second connection portion 62. The extending portion 63 connects the first connection portion 61 to the second connection portion 62.

In the present embodiment, the first connection portion 61, the second connection portion 62, and the extending portion 63 have a plate shape formed in the horizontal direction. In the present embodiment, each bus bar 42 is accommodated in the accommodation portion 55 at least over the first connection portion 61 and the second connection portion 62 and extends along the flat surface portion 51. For example, the first connection portion 61, the second connection portion 62, and the extending portion 63 are accommodated in the accommodation portion 55 and extend along the flat surface portion 51.

In the present embodiment, the extending portions 63 of some of the bus bars 42 are accommodated in the accommodation portion 55 to extend over both sides of a region R through the region R overlapping the electronic component 10 when viewed from the Z direction. For example, the extending portion 63 extends linearly in the X direction. The extending portion 63 extends over a region R overlapping the electronic component when viewed from the Z direction, over the +X direction side and the −X direction side of the region R. That is, the bus bar 42 is accommodated in the accommodation portion 55 to be easily routed through a better path (for example, a path with a shorter distance) without being disturbed by the presence of the electronic component 10.

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

Some routing examples of the bus bar 42 will be described below. The plurality of electronic components 10 include three electronic components 10A, 10B, and 10C. The electronic component 10A and the electronic component 10B are, for example, the first-type electronic component 10M. The electronic component 10C is, for example, the second-type electronic component 10N. Note that the type of the electronic component is not limited to the above example. The plurality of connection components 20 include six connection components 20A, 20B, 20C, 20D, 20E, and 20F. The plurality of connection components 30 include two connection components 30A and 30B. The plurality of coupling bus bars 75 include two coupling bus bars 75A and 75B. The plurality of external coupling bus bars 76 include two external coupling bus bars 76A and 76B.

First Routing Example

First, a routing example related to the bus bar 42A will be described. The bus bar 42A has the first connection portion 61, the second connection portion 62, and extending portion 63. The first connection portion 61 is located on the +X direction side with respect to the electronic component 10A when viewed from the Z direction. The first connection portion 61 is electrically connected to the terminal 13A of the electronic component 10A via the connection component 20A that is the first connection component 20. The second connection portion 62 is located on the −X direction side with respect to the electronic component 10A when viewed from the Z direction. The second connection portion 62 is electrically connected to another subunit SU via the coupling bus bar 75A.

The extending portion 63 is accommodated in the accommodation portion 55 to extend over both sides of the region R through the region R overlapping the electronic component 10A when viewed from the Z direction. For example, the extending portion 63 extends linearly in the X direction. The extending portion 63 extends over the region R overlapping the electronic component 10A when viewed from the Z direction, over the +X direction side and the −X direction side of the region R. The bus bar 42A is an example of a “first bus bar”. The accommodation portion 55A that accommodates the bus bar 42A is an example of a “first accommodation portion”. The bus bar 42A is, for example, a bus bar included in the positive electrode line PL included in the electrical connection unit 1.

Second Routing Example

Next, a routing example related to the bus bar 42B will be described. The bus bar 42B has the first connection portion 61, the second connection portion 62, the extending portion 63, and the extension 64. The first connection portion 61 is electrically connected to the terminal 13B of the electronic component 10A via the connection component 20B that is the first connection component 20. The second connection portion 62 is electrically connected to the external connection bus bar 76A via the connection component 30A that is the second connection component 30. The extension 64 extends to the region R overlapping the electronic component 10A when viewed from the Z direction, and has an end 42e1 of the bus bar 42 at a position overlapping the electronic component 10A. Similarly to the bus bar 42A, the bus bar 42B may have an extending portion 63 that extends through the region R overlapping the electronic component 10 and over both sides of the region R when viewed from the Z direction. The bus bar 42B is another example of a “first bus bar”. The accommodation portion 55B that accommodates the bus bar 42B is another example of a “first accommodation portion”. The bus bar 42B is, for example, a bus bar included in the positive electrode line PL included in the electrical connection unit 1.

Third Routing Example

Next, a routing example related to the bus bar 42C will be described. The bus bar 42C includes the first connection portion 61, the second connection portion 62, the extending portion 63, and the extension 64. The first connection portion 61 is electrically connected to the terminal 13B of the electronic component 10B via the connection component 20C that is the first connection component 20. The second connection portion 62 is electrically connected to another subunit SU via the coupling bus bar 75B. The extension 64 extends to the region R overlapping the electronic component 10B when viewed from the Z direction, and has an end 42e1 of the bus bar 42 at a position overlapping the electronic component 10B when viewed from the Z direction. The bus bar 42C is another example of a “first bus bar”. The accommodation portion 55C that accommodates the bus bar 42C is another example of a “first accommodation portion”. The bus bar 42C is, for example, a bus bar included in the negative electrode line NL included in the electrical connection unit 1.

Fourth Routing Example

Next, a routing example related to the bus bar 42D will be described. The bus bar 42D has the first connection portion 61, the second connection portion 62, and the extending portion 63. The first connection portion 61 is electrically connected to the terminal 13A of the electronic component 10B via the connection component 20D that is the first connection component 20. The second connection portion 62 is electrically connected to the terminal 13B of the electronic component 10C via the connection component 20E that is the second connection component 20. The bus bar 42D is another example of a “first bus bar”. The accommodation portion 55D that accommodates the bus bar 42D is another example of a “first accommodation portion”. The bus bar 42D is, for example, a bus bar included in the negative electrode line NL included in the electrical connection unit 1.

Fifth Routing Example

Next, a routing example related to the bus bar 42E will be described. The bus bar 42E has the first connection portion 61, the second connection portion 62, and the extending portion 63. The first connection portion 61 is electrically connected to the terminal 13A of the electronic component 10C via the connection component 20F that is the first connection component 20. The second connection portion 62 is electrically connected to the external connection bus bar 76B via the connection component 30B that is the second connection component 30. The bus bar 42E is another example of a “first bus bar”. The accommodation portion 55E that accommodates the bus bar 42E is another example of a “first accommodation portion”. The bus bar 42E is, for example, a bus bar included in the negative electrode line NL included in the electrical connection unit 1.

Next, referring to FIG. 9 again, the fastening member 43 will be described. The fastening member 43 is a component for fixing the bus bar 42 to a connection target component (the connection component 20, the connection component 30, the coupling bus bar 75, or a connection component 100) of the bus bar 42. The fastening member 43 is, for example, a caulking bolt fixed to the bus bar 42. The fastening member 43 is an example of a “fastening portion”.

In the present embodiment, each of the first connection portion 61 and the second connection 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 43a and a head 43b. A circumferential surface of the shaft 43a has a screw groove. The head 43b has a diameter larger than that of the shaft 43a. The head 43b of the fastening member 43 is caulked and fixed to the bus bar 42 in a state in which the shaft 43a passes through the through-hole 42h of the bus bar 42. With this fixation, the fastening member 43 is electrically and physically connected to the bus bar 42 in a state in which the shaft 43a protrudes in the +Z direction from the through-hole 42h of the bus bar 42. The fastening member 43 is not limited to caulking fixation, and may be fixed to the bus bar 42 through welding or other methods.

In the present embodiment, the connection component 20 is attached to the fastening member 43 from the Z direction in a state of being previously fixed to the electronic component 10 via the fastening member 72 or the fastening member 71. For example, in the connection component 20, the shaft portion 43a of the fastening member 43 is inserted into the second attachment hole 22h of the second portion 22. The engagement member 44 (for example, a nut) is engaged with the shaft portion 43a of the fastening member 43 protruding from the second attachment hole 22h of the second portion 22 of the connection component 20. The engagement member 44 is attached to the shaft 43a in the Z direction, for example. This engagement fixes the second portion 22 of the connection component 20 to the fastening member 43.

4. Metal Plate, Insulating Sheet, Heat Transfer Member, and Insulating Cover

Next, the metal plate 80, the insulating sheet 91, the heat transfer member 92, and the insulating cover 93 will be described.

FIG. 11 is a partially exploded perspective view of the electrical connection unit 1. The metal plate 80 is a member for securing rigidity of the electrical connection unit 1 and enhancing a heat dissipation property of the electrical connection unit 1. The metal plate 80 is made of a metal (for example, aluminum or an aluminum alloy). The metal plate 80 may be referred to as a “rigid member”.

The metal plate 80 has a rectangular shape formed in the X direction when viewed from the Z direction. The metal plate 80 has a first end 801e, a second end 80e2, a third end 80e3, and a fourth end 80e4. The first end 801e and the second end 80e2 are a pair of ends of the metal plate 80 in the longitudinal direction, and are separated in the X direction. The third end 80e3 and the fourth end 80e4 are a pair of ends of the metal plate 80 in the lateral direction, and are separated in the Y direction. The metal plate 80 includes, for example, a flat surface portion 81, a plurality of fixing portions 82, and a plurality of fixing portions 83.

The flat surface portion 81 is a portion formed in a plate shape in the metal plate 80. The flat surface portion 81 has a plate shape formed in the horizontal direction. The flat surface portion 81 forms a main portion of the metal plate 80. The flat surface portion 81 forms a base portion (metal base portion) of the metal plate 80. In the present embodiment, the flat surface portion 81 has a size that covers the three subunits SU from below. The flat surface portion 81 faces the routing boards 40 of the three subunits SU. In the present embodiment, the metal plate 80 has a gap S1 (see FIG. 13) formed between the metal plate 80 and the second surface 51b of the flat surface portion 51 of each subunit SU, and faces the second surface 51b of the flat surface portion 51 of each subunit SU. The gap S1 is an example of a “first gap”.

The fixing portion 82 is a fixing portion for fixing the base plate 41 of each subunit SU to the metal plate 80. The fixing portion 82 is provided at a position corresponding to the fixing portion 52 of the base plate 41 of each subunit SU when viewed from the Z direction. The fixing portion 82 is a cylindrical or prismatic boss protruding in the +Z direction from the flat surface portion 81 of the metal plate 80.

The fixing portion 83 is a fixing portion for directly fixing the electronic component 10 of each subunit SU to the metal plate 80 without interposing the base plate 41. The fixing portion 83 is provided at a position corresponding to the attachment portion 14 of the electronic component 10 of each subunit SU when viewed from the Z direction. The fixing portion 83 is a cylindrical or prismatic boss protruding in the +Z direction from the flat surface portion 81.

The insulating sheet 91 is an insulating member for electrically insulating the metal plate 80 and the bus bar 42 of each subunit SU. The insulating sheet 91 is made of, for example, a synthetic resin such as polyester or polyimide, and has an insulating property. The insulating sheet 91 has a rectangular shape when viewed from the Z direction. The insulating sheet 91 has a sheet shape formed in the horizontal direction. The insulating sheet 91 is disposed between the flat surface portion 81 of the metal plate 80 and the routing board 40 of each subunit SU. For example, the insulating sheet 91 is disposed between the flat surface portion 81 of the metal plate 80 and the plurality of heat transfer members 92.

In the present embodiment, the insulating sheet 91 is attached to the flat surface portion 81 of the metal plate 80. The insulating sheet 91 has a notch or an opening for avoiding the fixing portion 82 and the fixing portion 83 of the metal plate 80. Note that, instead of the above example, the insulating sheet 91 may be provided between the routing board 40 of each subunit SU and the plurality of heat transfer members 92. Note that, in a case where the heat transfer member 92 has an insulating property and the necessary insulating property is secured by the heat transfer member 92, the insulating sheet 91 may be omitted.

The heat transfer member 92 is a member for transferring heat generated by the electronic component 10 at the time of energization and/or heat (Joule heat) generated by the bus bar 42 itself at the time of energization to the metal plate 80. The heat transfer member 92 is, for example, a heat transfer sheet (for example, a thermally conductive silicone sheet) having elasticity. The heat transfer member 92 is made of a material having higher thermal conductivity than that of the base plate 41, for example. However, the heat transfer member 92 is not limited to the above example, and may be a heat transfer member made of a thermally conductive gel or another material.

FIG. 12 is a bottom view illustrating the routing board 40. In the present embodiment, the plurality of heat transfer members 92 are partially provided in the routing board 40. For example, the plurality of heat transfer members 92 are disposed at positions overlapping part of the bus bar 42 when viewed from the Z direction. More specifically, the plurality of heat transfer members 92 are disposed at positions overlapping part of the bus bar 42 in the vicinity of the electronic component 10 (for example, the electronic components 10A and 10B) when viewed from the Z direction. In the present embodiment, the plurality of heat transfer members 92 are disposed at positions overlapping the connection component 20 when viewed from the Z direction.

FIG. 13 is a cross-sectional view taken along line F13-F13 of the structure illustrated in FIG. 10. In the present embodiment, the heat transfer member 92 is disposed between the metal plate 80 and the bus bar 42. The heat transfer member 92 transfers heat transferred from the electronic component 10 to the bus bar 42 and/or heat generated by the bus bar 42 from the bus bar 42 to the metal plate 80. The electronic component 10 in this drawing is located at a predetermined distance in the Z direction away from the base plate 41 by appropriately adjusting a dimension in the Z direction of a fixing portion 83 that will be described later or by placing a spacer or the like adjacent to the fixing portion 83 in the Z direction.

In the present embodiment, part of the heat transfer member 92 is in contact with the bus bar 42 at a position overlapping the connection component 20 when viewed from the Z direction. In this case, the heat transfer member 92 easily transfers the heat transferred from the terminal 13 of the electronic component 10 to the connection component 20 from the connection component 20 to the metal plate 80 via the bus bar 42.

In the present embodiment, part of the heat transfer member 92 is disposed at a position overlapping 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 easily transfers the heat transferred from the terminal 13 of the electronic component 10 to the connection component 20 from the fastening member 43 to the metal plate 80.

In the present embodiment, part of the heat transfer member 92 is in contact with the bus bar 42 at a position overlapping the electronic component 10 when viewed from the Z direction. In this case, the heat transfer member 92 easily transfers the heat transferred from the electronic component 10 to the bus bar 42 from the bus bar 42 to the metal plate 80. In the example illustrated in FIG. 13, the upper surface of the bus bar 42 is in contact with the electronic component 10, and thus the bus bar 42 is thermally connected to the electronic component 10. Note that the bus bar 42 may be thermally connected to the electronic component 10 at the extending portion 63 or the extension 64.

Referring to FIG. 1 again, the insulating cover 93 will be described. The insulating cover 93 is a member for preventing the main body MU from coming into contact with the energization path. The insulating cover 93 is made of, for example, a synthetic resin and has an insulating property. The insulating cover 93 has, for example, a box shape that is open on the −Z direction side. The insulating cover 93 has a plurality of vent holes 93h. The insulating cover 93 is attached to the metal plate 80 in the Z direction. Note that the insulating cover 93 is not limited to a box-shaped member, and may be a sheet-shaped member that covers the energization path of the main body MU.

5. Exposure Structure of Bus Bar

Next, an exposure structure of the bus bar 42 will be described.

<5.1 Exposure Structure on Upper Surface Side of Bus Bar>

First, an exposure structure on the upper surface side of the bus bar 42 will be described with reference to FIG. 8. In the present embodiment, at least part of the extending portion 63 of the bus bar 42 is exposed to the outside of the base plate 41 on the upper surface side (the first surface 51a side of the flat surface portion 51). For example, the extending portion 63 of the bus bar 42 is exposed to the outside of the base plate 41 on the upper surface side at least in part of the region R (see FIG. 10) overlapping the electronic component 10 when viewed from the Z direction.

In the present embodiment, the bus bar 42 is accommodated in the accommodation portion 55 at least over the entire length between the first connection portion 61 and the second connection portion 62 and extends along the first surface 51a of the flat surface portion 51. The bus bar 42 is exposed to the outside of the base plate 41 on the upper surface side at least over the entire length between the first connection portion 61 and the second connection portion 62.

In the present embodiment, the bus bar 42 is accommodated in the accommodation portion 55 over the entire length of the bus bar 42 and extends along the first surface 51a of the flat surface portion 51. The bus bar 42 is exposed to the outside of the base plate 41 on the upper surface side over the entire length of the bus bar 42.

As illustrated in FIG. 13, at least part of the extending portion 63 of the bus bar 42 is exposed to the outside of the base plate 41 not only on the upper surface side but also on the lower surface side (second surface 51b side). For example, the bus bar 42 is exposed to the outside of the base plate 41 on the lower surface side over the entire length of the bus bar 42.

As illustrated in FIG. 14, the first connection portion 61 electrically connected to the first electronic component 10 protrudes from the first surface 51a to the outside of the accommodation portion 55 in the first direction (Z direction). In other words, the first surface 51a is recessed in the Z direction with respect to the first connection portion. In this case, part of the side peripheral surface 42CS of the bus bar 42 is exposed to the outside of the base plate 41. The side peripheral surface 42CS is directed in a direction intersecting the first direction.

The thickness of the bus bar 42 in the first direction (Z direction) may be larger than the thickness of the first surface 51a of the base plate 41 in the Z direction. As a result, the cross-sectional area of the bus bar 42 can be increased compared with a case where the thickness of the bus bar 42 and the thickness of the first surface 51a of the base plate 41 have the same value. A larger rated current can be adopted for the electrical connection unit 1 including the bus bar 42. The rated current is obtained by substituting a cross-sectional area into the definition of an upper limit value of a current density with respect to a rated current (“current density of strip-shaped conductor” of JIS C 8480:2016). At that time, as described above, since part of the side peripheral surface 42CS is exposed to the outside of the base plate 41, the heat dissipation performance of the bus bar 42 is improved.

Note that details described in FIG. 14 may be applied to the second connection component 20 instead of the first connection component 20. As described above, the second connection component 20 electrically connects the second electronic component or an external device to the bus bar 42.

Note that details described in FIG. 14 may be applied to the coupling bus bar 75 instead of the first connection component 20. As described above, the coupling bus bar 75 electrically connects the bus bars of the plurality of subunits (for example, three subunits SUX, SUY, and SUZ) to the bus bars 42. In this case, a contact surface between the coupling bus bar 75 and the bus bar 42 protrudes from the first surface 51a in the first direction (Z direction).

<5.2 Exposure Structure on Lower Surface Side of Bus Bar>

The exposure structure on the lower surface side of the bus bar 42 will be described with reference to FIG. 13 again. In the present embodiment, the plate portion 42p of the bus bar 42 includes an exposed portion 42u exposed to the outside of the base plate 41 on the lower surface side (the second surface 51b side of the flat surface portion 51). In the present embodiment, the exposed portion 42u of the bus bar 42 extends over the entire length of the bus bar 42. In the present embodiment, the heat transfer member 92 is disposed between the exposed portion 42u of the bus bar 42 and the metal plate 80. For example, the heat transfer member 92 is in contact with the exposed portion 42u of the bus bar 42.

In the present embodiment, at least part of the exposed portion 42u of the bus bar 42 is provided in a region overlapping the connection component 20 when viewed from the Z direction. At least part of the heat transfer member 92 overlaps the exposed portion 42u of the bus bar 42 in a region overlapping the connection component 20 when viewed from the Z direction. For example, at least part of the heat transfer member 92 is in contact with the exposed portion 42u of the bus bar 42 in a region overlapping the connection component 20 when viewed from the Z direction.

In the present embodiment, the exposed portion 42u of the bus bar 42 includes a first portion 42ua disposed in a region overlapping the connection component 20 when viewed from the Z direction and a second portion 42ub disposed in a region overlapping the electronic component 10 when viewed from the Z direction.

The heat transfer member 92 includes a first heat transfer portion 92a and a second heat transfer portion 92b. The first heat transfer portion 92a overlaps the first portion 42ua of the exposed portion 42u of the bus bar 42 in a region overlapping the connection component 20 when viewed from the Z direction. For example, the first heat transfer portion 92a is in contact with the first portion 42ua of the exposed portion 42u of the bus bar 42. On the other hand, the second heat transfer portion 92b overlaps the second portion 42ub of the exposed portion 42u of the bus bar 42 in a region overlapping the electronic component 10 when viewed from the Z direction. For example, the second heat transfer portion 92b is in contact with the second portion 42ub of the exposed portion 42u of the bus bar 42.

As described above, at least part of the extending portion 63 of the bus bar 42 is exposed to the outside of the base plate 41 not only on the lower surface side but also on the upper surface side (first surface 51a side). For example, the bus bar 42 is exposed to the outside of the base plate 41 on the upper surface side over the entire length of the bus bar 42. For example, the second portion 42ub of the exposed portion 42u of the bus bar 42 is exposed to the outside of the base plate 41 not only on the lower surface side but also on the upper surface side, and faces the electronic component 10.

6. Three-Dimensional Routing Structure of Bus Bar

Next, a three-dimensional routing structure CS of the bus bar 42 will be described.

FIG. 15 is a perspective view illustrating the three-dimensional routing structure CS of the bus bar 42. FIG. 16 is a plan view illustrating the three-dimensional routing structure CS of the bus bar 42. The three-dimensional routing structure CS includes a bus bar 42F, a bus bar 42G, a bus bar 42H, and a bus bar 42I as the plurality of bus bars 42. In addition, the three-dimensional routing structure CS includes a plurality of connection components 100. The three-dimensional routing structure CS includes a coupling bus bar 75C and a coupling bus bar 75D as the plurality of coupling bus bars 75.

The bus bar 42F and the bus bar 42G are, for example, the bus bars 42 included in the subunit SUY. The flat surface portion 51 of the base plate 41 of the subunit SUY includes an accommodation portion 55F and an accommodation portion 55G as the plurality of accommodation portions 55. The bus bar 42F is accommodated in the accommodation portion 55F and extends along the flat surface portion 51. The bus bar 42G is accommodated in the accommodation portion 55G and extends along the flat surface portion 51. The bus bar 42F is an example of a “first bus bar”. The accommodation portion 55F that accommodates the bus bar 42F is an example of a “first accommodation portion”. The accommodation portion 55G that accommodates the bus bar 42G is an example of a “fourth accommodation portion”. The bus bar 42F and the bus bar 42G are the bus bars 42 located in the first layer (lower layer) in the three-dimensional routing structure CS.

In the present embodiment, the bus bar 42F includes a first portion 42Fa extending in the X direction and a second portion 42Fb bent from the first portion 42Fa and extending in the Y direction. The second portion 42Fb extends along a boundary B between the subunit SUY and the subunit SUZ.

On the other hand, the bus bar 42H and the bus bar 42I are, for example, the bus bars 42 included in the subunit SUZ. The flat surface portion 51 of the base plate 41 of the subunit SUZ includes an accommodation portion 55H and an accommodation portion 55I as the plurality of accommodation portions 55. The bus bar 42H is accommodated in the accommodation portion 55H and extends along the flat surface portion 51. The bus bar 42I is accommodated in the accommodation portion 55I and extends along the flat surface portion 51. The bus bar 42H and the bus bar 42I are the bus bars 42 located in the first layer (lower layer) in the three-dimensional routing structure CS.

The connection component 100 has the same constitution as the connection component 30 for external connection described above. For example, the connection component 100 has a first portion 101, a second portion 102, and a third portion 103. For details of the connection component 100, in the above description regarding the connection component 30, the “connection component 30” may be replaced with the “connection component 100”, the “first portion 31” may be replaced with the “first portion 101”, the “first attachment hole 31h” may be replaced with the “first attachment hole 101h”, the “second portion 32” may be replaced with the “second portion 102”, the “second attachment hole 32h” may be replaced with the “second attachment hole 102h”, and the “third portion 33” may be replaced with the “third portion 103”. The connection component 100 is a member forming an energization path in the vertical direction. The connection component 100 may be referred to as a “vertical routing member”.

The plurality of connection components 100 include a connection component 100A and a connection component 100B. The connection component 100A overlaps the second connection portion 62 of the bus bar 42G in the subunit SUY when viewed from the Z direction. The connection component 100A is adjacent to the second connection portion 62 of the bus bar 42G in the Z direction, and is connected to the second connection portion 62 of the bus bar 42G from the Z direction. The connection component 100A stands in the +Z direction from the bus bar 42G. The connection component 100A is an example of a “third connection component”.

The connection component 100B overlaps the second connection portion 62 of the bus bar 42I in the subunit SUZ when viewed from the Z direction. The connection component 100B is adjacent to the second connection portion 62 of the bus bar 42I in the Z direction, and is connected to the second connection portion 62 of the bus bar 42I from the Z direction. The connection component 100B stands in the +Z direction from the bus bar 42I.

One end of the coupling bus bar 75C is adjacent to the second connection portion 62 of the bus bar 42F in the Z direction and is connected to the second connection portion 62 of the bus bar 42F from the Z direction in the subunit SUY. The other end of the coupling bus bar 75C is adjacent to the second connection portion 62 of the bus bar 42H in the Z direction and is connected to the second connection portion 62 of the bus bar 42H from the Z direction in the subunit SUZ. With this constitution, the bus bar 42F of the subunit SUY and the bus bar 42H of the subunit SUZ are electrically connected via the coupling bus bar 75C. The coupling bus bar 75C is the bus bar 75 located in the first layer (lower layer) in the three-dimensional routing structure CS.

On the other hand, in the subunit SUY, the coupling bus bar 75D is adjacent to the first portion 101 of the connection component 100A in the Z direction, and is connected to the first portion 101 of the connection component 100A from the Z direction. The other end of the coupling bus bar 75D is adjacent to the first portion 101 of the connection component 100B in the Z direction in the subunit SUZ, and is connected to the first portion 101 of the connection component 100B from the Z direction.

The coupling bus bar 75D is supported by the first portion 101 of the connection component 100A and the first portion 101 of the connection component 100B at a position away from the bus bar 42F in the Z direction. The coupling bus bar 75D is supported by the first portion 101 of the connection component 100A and the first portion 101 of the connection component 100B, and extends in the horizontal direction (for example, the X direction). The coupling bus bar 75D is electrically connected to the first portion 101 of the connection component 100A and the first portion 101 of the connection component 100B. With this constitution, the bus bar 42F of the subunit SUY and the bus bar 42I of the subunit SUZ are electrically connected via the two connection components 100 and the coupling bus bar 75D.

In the present embodiment, the coupling bus bar 75D extends to straddle the second portion 42Fb of the bus bar 42F at a position away from the bus bar 42F in the +Z direction. As a result, a three-dimensional intersecting structure is formed by the coupling bus bar 75D and the bus bar 42F. In the present embodiment, the coupling bus bar 75D extends to straddle the boundary B of the plurality of subunits SU.

In the present embodiment, the three-dimensional routing structure CS of the bus bar 42 is provided at a position of straddling the boundary B of the plurality of subunits SU. According to such a disposition, the coupling structure between the plurality of subunits SU is reinforced by the three-dimensional routing structure CS. Note that the three-dimensional routing structure CS of the bus bar 42 may be provided inside one or more subunits SU instead of being provided at the boundary B of the plurality of subunits SU.

As a comparative example, an electrical connection unit in which a bus bar is disposed in a standing posture with respect to a lower wall of a housing will be considered. In such a constitution of the comparative example, for example, since a cross-sectional area of a bus bar is determined in order to function as a routing member, it may be difficult to reduce a width (height) of the standing bus bar. In this case, the width of the standing bus bar becomes a bottleneck, and it may be difficult to reduce a height of the electrical connection unit.

On the other hand, in the present embodiment, the electrical connection unit 1 includes the first electronic component 10 and the routing board 40. The routing board includes a base member 41 and a first bus bar 42. The base member 41 has a plate-shaped or sheet-shaped flat surface portion 51 having a first surface 51a facing the first electronic component 10. The flat surface portion 51 has the first accommodation portion 55 recessed in the Z direction or penetrating the flat surface portion 51 in the Z direction. The first bus bar 42 has a first connection portion (for example, a contact portion corresponding to a contact surface COS) electrically connected to the first electronic component 10, at least part of the first bus bar 42 is accommodated in the first accommodation portion 55 and extends along the flat surface portion 51, and at least the first connection portion protrudes from the first surface to the outside of the first accommodation portion in the first direction. According to such a constitution, compared with the structure of the comparative example in which at least part of the routing path is formed on a plane, the width of the bus bar is less likely to be a bottleneck, and the height of the electrical connection unit 1 can be easily reduced.

In the present embodiment, attention is also paid to an assembly state when the first electronic component 10 and the bus bar 42 are electrically connected via the first connection component 20 after the bus bar 42 is accommodated in the accommodation portion 55. For example, when the first connection component 10 (or a terminal 13 according to a modification example that will be described later) is in contact with both the bus bar 42 and the base plate 41, if the first surface 51a of the base plate 41 protrudes in the first direction (Z direction) with respect to a contact portion (first connection portion) corresponding to the contact surface COS, the first surface 51a pushes up the first connection component 20 in the +Z direction. The contact area of the contact surface COS is less likely to be secured, and the electrical connection of the first electronic component 10 is less likely to be ensured.

In the present embodiment, the first connection portion 61 protrudes from the first surface 51a to the outside of the accommodation portion 55 in the first direction (Z direction). According to such a constitution, the first surface 51a hardly pushes up the first connection component 20 in the +Z direction. Since the contact area of the contact surface COS is easily secured, the electrical connection of the first electronic component is easily ensured.

In the present embodiment, the thickness of the bus bar 42 at least in the first direction (Z direction) is larger than the thickness of the flat surface portion 51 of the base member (for example, the base plate 41) in the first direction. According to such a constitution, it is possible to increase the cross-sectional area of the bus bar 42 compared with a case where the thickness of the bus bar 42 and the thickness of the first surface 51a of the base plate 41 have the same value. A larger rated current can be adopted for the electrical connection unit 1 including the bus bar 42. The rated current is obtained by substituting a cross-sectional area into the definition of an upper limit value of a current density with respect to a rated current (“current density of strip-shaped conductor” of JIS C 8480:2016).

In the present embodiment, the first connection component 10 provided between the first electronic component 10 and the first connection portion 61 (alternatively, the second connection portion 62) is further provided, and the contact surface COS between the first connection component 10 and the first connection portion is provided outside the accommodation portion 55 and at a position away from the first surface 51a in the first direction (Z direction). According to such a constitution, at least part of heat generated by the bus bar 42 itself due to energization can be stored (absorbed) in the first connection component 10. As a result, the amount of heat transferred from the bus bar 42 to the base member (for example, the base plate 41) via the accommodation portion 55 is dispersed in the first connection component 10. Since the amount of transferred heat decreases, deformation of the base plate 41 due to thermal expansion to thermal contraction can be curbed.

In the present embodiment, the bus bar 42 is accommodated in the accommodation portion 55 over the entire length of the bus bar 42, extends along the flat surface portion 51, and is exposed to the outside of the base plate 41 on the first surface 51a side. According to such a constitution, since the wider portion functions as a heat dissipation area, the heat dissipation property of the electrical connection unit 1 can be further improved.

In the present embodiment, part of the side peripheral surface 42CS of the bus bar 42 directed in the direction intersecting the first direction (Z direction) is exposed to the outside of the accommodation portion 55. According to such a constitution, since part of the side peripheral surface 42CS functions as a heat dissipation area, the heat dissipation property of the electrical connection unit 1 can be further improved.

In the present embodiment, the bus bar 42 is integrated with a base member (for example, the base plate 41). According to such a constitution, it is possible to eliminate or reduce the work of manually attaching the bus bar 42 to the housing. Since the bus bar 42 is less likely to fall off from the accommodation portion 55, the assemblability of the electrical connection unit 1 can be further improved. For example, the bus bar 42 is integrated with the base member (for example, the base plate 41) through insert molding.

In addition, as another comparative example, an electrical connection unit in which a synthetic resin adheres to the upper surface side of the bus bar 42 through insert molding will be considered. In such a constitution of the comparative example, a contact area between the bus bar 42 and the first connection component 20 is reduced, and it is difficult to secure electrical connection.

In the present embodiment, a contact surface between the first connection component and the first bus bar protrudes from the first surface in the first direction. According to such a constitution, it is also considered that the first surface is recessed in the first direction with respect to the contact surface. At the time of insert molding, the synthetic resin easily moves from the upper surface of the bus bar 42 serving as the contact surface toward the first surface. Therefore, the synthetic resin is less likely to adhere to the upper surface side of bus bar 42 during insert molding.

In the present embodiment, the bus bar 42 is accommodated in the accommodation portion 55 over the entire length of the bus bar 42 and extends along the flat surface portion 51. According to such a constitution, it is easy to reduce the height of the electrical connection unit 1 while improving the assemblability of the electrical connection unit 1.

In the present embodiment, the bus bar 42 is accommodated in the accommodation portion 55 over the entire length of the bus bar 42, extends along the flat surface portion 51, and is exposed to the outside of the base plate 41 on the first surface 51a side. According to such a constitution, since the wider portion functions as a heat dissipation area, the heat dissipation property of the electrical connection unit 1 can be further improved.

In a modification example that will be described later, the bus bar 42 is covered with an insulating sheet. According to such a constitution, it is easy to reduce the voltage drop and the inductance from the bus bar not subjected to lamination processing.

In addition, as another comparative example, an electrical connection unit in which a synthetic resin adheres to the upper surface side of the bus bar 42 through insert molding will be considered. In such a constitution of the comparative example, a contact area between the bus bar 42 and the first connection component 20 is reduced, and it is difficult to secure electrical connection.

In the present embodiment, a contact surface between the first connection component and the first bus bar protrudes from the first surface in the first direction. According to such a constitution, it is also considered that the first surface is recessed in the first direction with respect to the contact surface. At the time of insert molding, the synthetic resin easily moves from the upper surface of the bus bar 42 serving as the contact surface toward the first surface. Therefore, the synthetic resin is less likely to adhere to the upper surface side of bus bar 42 during insert molding.

In the present embodiment, there is further provided the second connection component 20 that includes a portion standing with respect to the bus bar 42 and electrically connects the second electronic component 20 or an external device to the bus bar 42 (for example, the bus bar 42B, the bus bar 42D, the bus bar 42E, or the bus bar 42G), and the contact surface between the second connection component 20 and the bus bar 42 protrudes from the first surface 51a in the first direction (Z direction). According to such a constitution, the first surface 51a of the base plate 41 is less likely to protrude in the Z direction with respect to the contact surface, and the first surface 51a is less likely to push up the second connection component 20 in the +Z direction. Since the contact area of the contact surface is easily secured, the electrical connection of the second electronic component 20 is easily ensured.

In the present embodiment, there are further provided a second bus bar (for example, bus bars of three subunits SUX, SUY, and SUZ) and the coupling bus bar 75 that electrically connects the second bus bar to the bus bar 42, and a contact surface between the coupling bus bar 75 and the bus bar 42 (for example, the bus bar 42A, bus bar 42C, bus bar 42F) protrudes from the first surface 51a in the first direction (Z direction). According to such a constitution, the first surface 51a of the base plate 41 is less likely to protrude in the Z direction with respect to the contact surface, and the first surface 51a is less likely to push up the coupling bus bar 75 in the +Z direction. Since the contact area of the contact surface COS is easily secured, the electrical connection of the coupling bus bar 75 is easily ensured.

Second Embodiment

Next, a second embodiment will be described. The second embodiment is different from the first embodiment in that an insulating rib 53 is provided between two adjacent bus bars 42. Constitutions other than that described below are the same as the constitutions of the first embodiment.

FIG. 17 is a perspective view for describing the insulating rib 53. In the present embodiment, the base plate 41 has the insulating rib 53. The insulating rib 53 is a rib standing in the +Z direction from the first surface 51a of the flat surface portion 51. The insulating rib 53 is made of a synthetic resin and has an insulating property. The insulating rib 53 is provided as part of the base plate 41, for example. The insulating rib 53 is disposed between the two bus bars 42 disposed to be arranged in a state in which upper surface sides thereof are exposed, and secures an insulating distance between the two bus bars 42.

In the present embodiment, the routing board 40 includes a bus bar 42J and a bus bar 42K as the plurality of bus bars 42. In addition, the base plate 41 includes an accommodation portion 55J and an accommodation portion 55K as the plurality of accommodation portions 55.

At least part of the bus bar 42J is accommodated in the accommodation portion 55J and extends along the flat surface portion 51. The bus bar 42J is electrically connected to the terminal 13A of one electronic component 10 (hereinafter, referred to as a “first electronic component 10” in some cases) via the connection component 20. The bus bar 42J protrudes from the first surface 51a in the first direction (Z direction), similarly to the bus bar 42 described in the first embodiment. The bus bar 42J is an example of a “first bus bar”. The accommodation portion 55J is an example of a “first accommodation portion”.

At least part of the bus bar 42K is accommodated in the accommodation portion 55K and extends along the flat surface portion 51. The bus bar 42K is electrically connected to the terminal 13 of another electronic component 10 (second electronic component) via another connection component 20. Alternatively, the bus bar 42J may be electrically connected to the terminal 13B of the first electronic component 10 via another connection component 20. The bus bar 42K protrudes from the first surface 51a in the first direction (Z direction), similarly to the bus bar 42 described in the first embodiment. The bus bar 42K is an example of a “second bus bar”. The accommodation portion 55K is an example of a “second accommodation portion”.

In the present embodiment, the subunit SU includes the connection component 30C and the connection component 30D as the plurality of connection components 30. The connection component 30C is adjacent to the bus bar 42J in the Z direction, and is connected to the bus bar 42J from the Z direction. The connection component 30C is electrically connected to a first external device via the external connection bus bar 76. The connection component 30D is adjacent to the bus bar 42K in the Z direction, and is connected to the bus bar 42K from the Z direction. The connection component 30D is electrically connected to the first external device or a second external device via another external connection bus bar 76. In the present embodiment, part of the insulating rib 53 is disposed between the connection component 30C (first connection component) and the connection component 30D (second connection component) to electrically insulate the connection component 30C (first connection component) from the connection component 30D (second connection component).

Note that the first connection component is not limited to the connection component 30, and may be the connection component 20 connected to another electronic component 10 (third electronic component) included in the same subunit SU. Similarly, the second connection component is not limited to the connection component 30, and may be the connection component 20 connected to another electronic component 10 (fourth electronic component) included in the same subunit SU.

In the present embodiment, the insulating rib 53 protrudes in the +Z direction from the first surface 51a at a position between the accommodation portion 55J and the accommodation portion 55K. The insulating rib 53 is an example of a “first rib”.

In the present embodiment, the bus bar 42J is accommodated in the accommodation portion 55J in a state of being exposed to the upper surface side (first surface 51a side), and includes, for example, a first straight portion 42Ja linearly extending in the X direction. The bus bar 42K is accommodated in the accommodation portion 55K in a state of being exposed to the upper surface side (first surface 51a side), and includes, for example, a second straight portion 42Ka linearly extending in the X direction. The first straight portion 42Ja of the bus bar 42J and the second straight portion 42Ka of the bus bar 42K are adjacent to each other in the Y direction, for example. The second straight portion 42Ka of the bus bar 42K extends in parallel with the first straight portion 42Ja of the bus bar 42J.

The insulating rib 53 is located between the first straight portion 42Ja of the bus bar 42J and the second straight portion 42Ka of the bus bar 42K when viewed from the Z direction, and extends in parallel with the first straight portion 42Ja of the bus bar 42J and the second straight portion 42Ka of the bus bar 42K. The first straight portion 42Ja of the bus bar 42J, the second straight portion 42Ka of the bus bar 42K, and the insulating rib 53 may extend linearly in the Y direction instead of the X direction.

FIG. 18 is a cross-sectional view taken along line F18-F18 of the structure illustrated in FIG. 17. As illustrated in FIG. 18, the insulating rib 53 is located between the side peripheral surface 42CS of the bus bar 42J and the side peripheral surface 42CS of the bus bar 42K in the Y direction. The insulating rib 53 electrically insulates the side peripheral surface 42CS of the bus bar 42J from the side peripheral surface 42CS of the bus bar 42K.

According to such a constitution, even in a case where the bus bar 42J and the bus bar 42K are disposed within a predetermined distance, a necessary insulation distance can be secured by the insulating rib 53. Therefore, the plurality of bus bars 42 can be easily disposed close to each other. In a case where the plurality of bus bars 42 are easily disposed close to each other, the electrical connection unit 1 can be miniaturized. For example, in the present embodiment, the insulating rib 53 is located between the side peripheral surface 42CS of the bus bar 42J and the side peripheral surface 42CS of the bus bar 42K in the Y direction. Therefore, providing the insulating rib 53 enables the bus bar 42J and the bus bar 42K having the exposed side peripheral surface CS to be easily disposed close to each other.

8. Modification Examples

Next, several modification examples will be described. Note that a constitution other than that described below in each modification example is the same as the constitution of the first embodiment.

First Modification Example

The routing board 40 is not limited to a structure in which the base plate 41 and the bus bar 42 are integrated through insert molding. For example, the bus bar 42 may be disposed in the accommodation portion 55 after the base plate 41 provided with the accommodation portion 55 for accommodating the bus bar 42 is molded. In this case, the bus bar 42 may be fixed to the accommodation portion 55 through fitting, or may be fixed to the accommodation portion 55 via an adhesive or other fixing means. In these cases, potting may be performed to fill a gap between the bus bar 42 and the accommodation portion 55.

Second Modification Example

A base member of the routing board 40 is not limited to the base plate 41 having the plate-shaped flat surface portion 51. The routing board 40 may be a base member (for example, an insulating sheet) having a sheet-shaped flat surface portion 51. In this case, the accommodation portion 55 may be formed by part of the flat surface portion 51 following the outer shape of the bus bar 42. In the present disclosure, the “sheet-shaped” or “sheet” is not limited to a member having a thickness of 1 mm or more, and a member (so-called a film) having a thickness of less than 1 mm can also be used.

Third Modification Example

A connection between the electronic component 10 and the bus bar 42 is not limited to the connection using the connection component 20. The electronic component may be directly connected to the bus bar 42 by using a fastening member (for example, a bolt or a screw), welding, or the like. For example, it is conceivable that the terminal 13 of the electronic component 10 and the bus bar 42 are brought into direct contact with each other through welding or the like.

Fourth Modification Example

The base plate 41 of the routing board 40 may include a plurality of members (plate members or sheet members). The plurality of members are provided to sandwich the plurality of bus bars 42 arranged in the horizontal direction, for example, from both sides in the Z direction. For example, the plurality of members are integrated by sandwiching the plurality of bus bars 42 through laminate molding, for example. The plurality of members form the flat surface portion 51. In this case, the accommodation portion 55 may be formed in a hollow shape 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 a plate member and a sheet member. The sheet member may be, for example, a flexible sheet member. The flat surface portion 51 formed of the plurality of members has an opening through which at least first connection portion 61 and second connection portion 62 of bus bar 42 are exposed. For example, in this case, the accommodation portion 55 formed between the plurality of members corresponds to an example of an “accommodation portion recessed in the first direction (Z direction)”.

Several embodiments and modification examples have been described above. However, the embodiment and the modification examples are not limited to the examples described above. For example, a plurality of embodiments may be implemented in combination with each other. The above-described embodiments can be implemented in various other forms, and various additions, omissions, substitutions, and changes can be made without departing from the concept of the present disclosure.

According to the present disclosure, the height of the electrical connection unit can be reduced.

REFERENCE SIGNS LIST