Circuit structure

Abstract

This invention discloses a novel circuit structure that advantageously ensures the waterproofness of the housing and the insulation between the heat dissipation part and the heat dissipation object. The circuit structure (10) includes: a heating element (12, 14) that generates heat when energized; a metal plate (18) connected to the heating element (12, 14) by a connection part (38, 44) and having a heat dissipation part (26) that makes thermal contact with an external heat dissipation object (29); a housing (24) that houses the heating element (12, 14) and the metal plate (18) and has an opening (28) through which the heat dissipation part (26) of the metal plate (18) is exposed to the outside; and an insulating film (30) that seals the opening (28) of the housing (24) to the housing (24).

Description

Technical Field

[0001] This disclosure relates to a circuit structure having a heat-generating component. Background Technology

[0002] Conventionally, in circuit structures containing heat-generating components such as relays and fuses that generate heat when energized, heat dissipation structures are sometimes provided to dissipate heat from these components. For example, Patent Document 1 discloses a structure in which the heat dissipation portion of a busbar connected to a relay housed within a housing is exposed to the outside through an opening in the housing, and this heat dissipation portion contacts the metal casing housing a battery via an insulating thermally conductive sheet. This allows heat generated by the relay to be dissipated to the casing.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-93711 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] When the inventors repeatedly studied such a circuit structure, they discovered that due to the temperature difference between the circuit structure and the outer casing, condensation sometimes occurs around the casing of the circuit structure fixed to the outer casing. Water accumulated due to condensation enters the casing from the opening of the casing, thus making it impossible to ensure the insulation between the outer casing and the heat dissipation part of the busbar.

[0008] Therefore, a new circuit structure is disclosed that can advantageously ensure the waterproofness of the housing and the insulation between the heat dissipation part and the heat dissipation object.

[0009] Solution for solving the problem

[0010] The circuit structure disclosed herein includes: a heating element that generates heat when energized; a metal plate connected to a connection portion of the heating element and having a heat dissipation portion that makes thermal contact with an external heat dissipation object; a housing that houses the heating element and the metal plate and has an opening through which the heat dissipation portion of the metal plate is exposed to the outside; and an insulating film that seals the opening of the housing to the housing.

[0011] Invention Effects

[0012] According to the circuit structure disclosed herein, the waterproofness of the housing and the insulation between the heat dissipation part and the heat dissipation object can be advantageously ensured. Attached Figure Description

[0013] Figure 1This is a three-dimensional view of the circuit structure of Implementation Method 1.

[0014] Figure 2 yes Figure 1 The top view of the circuit structure shown is a diagram of the circuit with the upper casing removed.

[0015] Figure 3 yes Figure 1 An exploded 3D view of the circuit structure shown.

[0016] Figure 4 yes Figure 2 Sectional view IV-IV.

[0017] Figure 5 yes Figure 2 VV sectional view.

[0018] Figure 6 yes Figure 1 The diagram shows a three-dimensional view of the lower housing that constitutes the circuit structure, viewed from the planar side.

[0019] Figure 7 yes Figure 6 The image shows a perspective view of the lower shell from the bottom side.

[0020] Figure 8 It is Figure 7 The enlarged view of the bottom surface of the lower shell shown is... Figure 6 A partial sectional perspective view equivalent to section VIII-VIII.

[0021] Figure 9 This is a longitudinal sectional view of another type of circuit structure, which is the same as... Figure 4 The corresponding diagram. Detailed Implementation

[0022] <Description of embodiments of this disclosure>

[0023] First, embodiments of this disclosure will be described.

[0024] (1) The circuit structure disclosed herein includes: a heating element that generates heat when energized; a metal plate connected to the connecting portion of the heating element and having a heat dissipation portion that makes thermal contact with an external heat dissipation object; a housing that houses the heating element and the metal plate and has an opening that exposes the heat dissipation portion of the metal plate to the outside; and an insulating film that seals the opening of the housing to the housing.

[0025] According to the circuit structure disclosed herein, the opening in the housing, which exposes the heat dissipation portion of the metal plate to the outside, is sealed with an insulating film. Therefore, even if condensation occurs around the housing of the circuit structure due to the temperature difference between the external heat dissipation object (e.g., a metal casing) and the circuit structure, the water accumulated due to condensation can be prevented from entering the housing through the opening. As a result, the waterproofness of the housing with the opening is improved, preventing short circuits between the heat dissipation portion and the heat dissipation object due to water entering the housing, and advantageously ensuring the insulation between the heat dissipation portion and the heat dissipation object. The metal plate can be used as long as it has a heat dissipation portion; its application is not limited. For example, a heat dissipation portion can be provided on a metal plate for power transmission, or on a heat dissipation metal plate separate from the metal plate for power transmission. Here, "exposing the heat dissipation portion of the metal plate to the outside" means that the heat dissipation portion can make thermal contact with the external heat dissipation object of the housing without passing through the housing.

[0026] It should be noted that the insulating film is not particularly limited as long as it has insulating properties and can be fixed to the shell by sealing the opening of the shell. However, it is advantageous to use a film-like structure made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE), polycarbonate (PC), polyimide (PI), etc. Furthermore, the thickness of the insulating film is not particularly limited, but in order to advantageously achieve thermal conductivity from the heat dissipation part to the heat dissipation object, a relatively thin film thickness is preferred, for example, 500 μm or less, more preferably 250 μm or less. Moreover, the insulating film can be fixed to the shell using known methods such as bonding or welding.

[0027] (2) Preferably, the housing includes an upper housing and a lower housing, and the heat-generating component is fixed to at least one of the upper housing and the lower housing. The lower housing has a mounting surface for placing the heat dissipation object, and the opening is provided on the mounting surface. The lower housing has a positioning part that positions the heat dissipation part of the metal plate disposed in the opening flush with the mounting surface. A connecting part is provided on the metal plate, which is the part where the metal plate connects to the connecting part of the heat-generating component. The circuit structure has a tolerance absorption structure that absorbs the tolerance of the connection position between the connecting part and the connecting part when the heat dissipation part is positioned by the positioning part.

[0028] The lower housing, assembled with the upper housing, has a mounting surface for placing the heat dissipation object. Furthermore, an opening is provided on the mounting surface for exposing the heat dissipation portion of the metal plate. The lower housing has a positioning portion where the heat dissipation portion is positioned flush with the mounting surface, thus suppressing or preventing the formation of a step between the heat dissipation portion and the mounting surface, which could negatively affect the fixation of the insulating film. Moreover, it is necessary to connect the connection portion of the metal plate, where the heat dissipation portion is positioned on the lower housing side, to the connection portion of the heat-generating component. However, the circuit structure has a tolerance-absorbing structure that absorbs the tolerances at the connection positions of the connection portions, allowing the connection portion of the metal plate where the heat dissipation portion is positioned on the lower housing to be connected to the connection portion of the heat-generating component without problems. It should be noted that the heat-generating component can be fixed to either the upper or lower housing; however, when the heat-generating component is fixed to the upper housing, during the assembly of the upper and lower housings, deviations in the tolerances of each component at the connection position between the heat-generating component and the metal plate tend to increase, thus the tolerance-absorbing effect is more effectively utilized.

[0029] The shape of the positioning part can be arbitrarily set as long as it can position the lower surface of the heat sink to be flush with the mounting surface of the lower housing. For example, a shape that makes the lower surface of the heat sink flush with the mounting surface by partially or completely contacting the upper surface of the heat sink can be adopted.

[0030] (3) In (2) above, preferably, the heating element includes a first heating element, the metal plate includes a metal plate for the first heating element, the metal plate for the first heating element is connected to the connecting part of the first heating element, the connecting part of the first heating element and the connecting part of the metal plate for the first heating element are connected by a first bolt, the first bolt extends in a direction orthogonal to the assembly direction of the upper shell and the lower shell, a bolt through hole in the shape of an elongated hole is provided at the connecting part of the metal plate for the first heating element, the bolt through hole extends along the assembly direction of the upper shell and the lower shell, and the bolt through hole constitutes a first tolerance absorption structure, the tolerance absorption structure includes the first tolerance absorption structure.

[0031] The connecting part of the first heating element and the connecting part of the metal plate for the first heating element are connected by a first bolt extending in a direction orthogonal to the assembly direction of the upper and lower housings. By setting the bolt through hole provided in the metal plate for the first heating element as an elongated hole extending along the assembly direction, a first tolerance absorption structure can be provided.

[0032] (4) In (3) above, preferably, the upper housing has a top wall and a side wall, the side wall protruding from the top wall toward the lower housing, the lower housing has a bottom wall and a peripheral wall, the peripheral wall protruding from the bottom wall toward the upper housing, and at least one of the side wall and the peripheral wall is provided with a working hole, the working hole being able to allow the first bolt and the tool for connecting the first bolt to be inserted.

[0033] This is because, after the upper shell is assembled onto the lower shell, the first heating element, which can position the heat dissipation part at the positioning part of the lower shell, is bolted from the outside of the upper shell to the connecting part of the first heating element by the connecting part of the metal plate. This allows for good workability in positioning the heat dissipation part and the lower shell, as well as tolerance absorption in the connection position of the connecting part and the connecting part.

[0034] (5) In (3) or (4) above, preferably, the first heating element is bent into an L-shape with a metal plate, one end of the first heating element is formed as the heat dissipation part, the heat dissipation part extends parallel to the mounting surface of the lower housing, the other end of the first heating element is formed as the connecting part that stands upright towards the upper housing, a recess and a slit-shaped insertion hole are provided on the mounting surface of the lower housing, the insertion hole allows the connecting part to be inserted, the recess is connected to the insertion hole and recessed towards the upper housing to accommodate the heat dissipation part, the opening is formed by the insertion hole and the recess, the top plate of the recess forms a positioning part for the first metal plate, the positioning part for the first metal plate positions the first heating element metal plate, and the positioning part includes the positioning part for the first metal plate.

[0035] By making the metal plate for the first heating element L-shaped, the opening area of ​​the through hole provided on the mounting surface of the lower housing can be reduced, and the connecting part of the metal plate for the first heating element can be inserted into the housing. Furthermore, by providing a recess that connects to the through hole and is recessed towards the upper housing, the heat dissipation part can be accommodated within the recess, making the heat dissipation part flush with the mounting surface. At this time, the top plate of the recess can form a positioning part for the first metal plate that makes the heat dissipation part flush with the mounting surface, thus the heat dissipation part can be stably held by the lower housing. In addition, the insulation between the heat dissipation part and the circuitry within the housing can be advantageously ensured.

[0036] (6) In any of (2) to (5) above, preferably, the heating element includes a second heating element, the metal plate includes a metal plate for the second heating element, the metal plate for the second heating element is connected to the connecting portion of the second heating element, the metal plate for the second heating element has: a heat dissipation portion, disposed on one end side of the metal plate for the second heating element and extending parallel to the mounting surface of the lower housing; a connecting portion, disposed on the other end side of the metal plate for the second heating element, located closer to the upper housing side than the heat dissipation portion and extending parallel to the heat dissipation portion; and a connecting portion, erected from the heat dissipation portion toward the connecting portion, having an insertion hole and a recess provided on the mounting surface of the lower housing, the insertion hole The connection portion and the connecting portion are allowed to pass through. The recess is connected to the through hole and recessed towards the upper housing to accommodate the heat dissipation portion. The opening portion is formed by the through hole and the recess. The top plate of the recess forms a positioning portion for the second metal plate. The positioning portion for the second metal plate positions the metal plate for the second heating element. The positioning portion includes the positioning portion for the second metal plate. The connection portion is connected to the connecting portion of the second heating element by a second bolt. The nut is held so that it can be displaced in a direction that separates from the mounting surface of the lower housing, thereby forming a second tolerance absorption structure. The nut is accommodated in the upper housing and connected to the second bolt. The tolerance absorption structure includes the second tolerance absorption structure.

[0037] The lower housing, assembled to the upper housing, has a mounting surface for placing a heat-dissipating object. Furthermore, an opening is provided on the mounting surface for exposing the heat-dissipating portion of the metal plate for the second heat-generating component. The lower housing has a positioning part for the second metal plate, with the heat-dissipating portion flush with the mounting surface, thus suppressing or preventing the formation of a step between the heat-dissipating portion and the mounting surface that could negatively affect the fixation of the insulating film. Additionally, it is necessary to connect the connecting part of the metal plate for the second heat-generating component, where the heat-dissipating portion is positioned on the lower housing side, to the connecting part of the second heat-generating component. However, the circuit structure has a second tolerance-absorbing structure that absorbs the tolerance of the connection position between the connecting part and the connecting part, thus allowing the connecting part of the metal plate for the second heat-generating component, where the heat-dissipating portion is positioned on the lower housing, to the connecting part of the second heat-generating component without any problems.

[0038] (7) In (6) above, preferably, the insertion hole has a first area that allows the connection part to be inserted and a second area that allows the connection part to be inserted, and the cover is fixed to the mounting surface in a detachable manner, the cover covering the first area in the insertion hole.

[0039] After connecting the metal plate of the second heating element to the connecting part of the heating element, the large-opening through hole can be covered by the cover, which exposes the connecting part of the metal plate of the second heating element, which is a live part. This advantageously improves the protection against electric shock and the waterproofing of the housing.

[0040] (8) Preferably, a plurality of protrusions are provided in the housing at intervals, the plurality of protrusions being disposed around the periphery of the insulating film.

[0041] Because multiple protrusions are provided around the periphery of the insulating film, approaching the periphery of the insulating film from the outer periphery becomes difficult due to these protrusions. This prevents operations such as lifting the periphery of the insulating film to peel it off, effectively ensuring the waterproofness of the housing. Furthermore, the multiple protrusions are spaced apart, so even when the insulating film is filled with spacer fillers, heat-dissipating resins, heat-conducting sheets, or other heat-conducting filling members, air can be advantageously expelled through the gaps between the protrusions, eliminating the undesirable situation where air accumulates between the insulating film and the filling member, reducing heat dissipation. It should be noted that the relative gap between the periphery of the insulating film and the protrusions, and / or the relative gap between the protrusions themselves, is preferably set to a size that prevents the intrusion of fingers.

[0042] (9) In (8) above, preferably, the housing includes an upper housing and a lower housing, and the plurality of protrusions are triangular in shape in the projection of the upper housing and the lower housing in the assembly direction, and are configured to gradually narrow in width as they move toward the insulating film located on the inner side.

[0043] Multiple protrusions, each formed in a triangular shape, are arranged with their width gradually narrowing towards the inward side, thus the gaps between the protrusions gradually increase towards the inward side. This facilitates the trapping of air between the insulating film and the filling member, enabling more efficient air expulsion. Furthermore, the gaps between the protrusions are minimized on the outer side, further enhancing the finger-proofing effect.

[0044] (10) Preferably, the heat dissipation portion contacts the heat dissipation object via a heat-conducting filling member disposed on the insulating film side.

[0045] Even when gaps exist between the contact surfaces of the heat dissipation part and the object being dissipated due to tolerances, a heat-conducting filler component placed between them can prevent the deterioration of heat transfer caused by the gaps, thus achieving good heat dissipation. For example, a composite material in which thermally conductive fillers are filled into resins such as epoxy resin or silicone resin can be used as the heat-conducting filler component. Fillers used to fill the resin include, for example, alumina, boron nitride, aluminum nitride, and silicon nitride. It should be noted that the heat-conducting filler component can be in various forms, such as sheet, gel, or grease.

[0046] <Details of the embodiments of this disclosure>

[0047] The following describes specific examples of the circuit structure of this disclosure with reference to the accompanying drawings. It should be noted that this disclosure is not limited to these examples, but is disclosed by the claims and includes all modifications within the meaning and scope equivalent to the claims.

[0048] <Implementation Method 1>

[0049] The following uses Figures 1 to 8 This section describes the circuit structure 10 of Embodiment 1 of this disclosure. The circuit structure 10 of Embodiment 1 is mounted in a vehicle (not shown), such as an electric motor or a hybrid electric vehicle, and supplies and controls power from a power source (not shown) such as a battery to a load (not shown) such as an electric motor. The circuit structure 10 can be configured in any orientation; however, in the following description, the X direction in the figures will be defined as forward, the Y direction as left, and the Z direction as upward. Furthermore, for multiple identical components, only a portion of the components will be labeled; for other components, the labels may sometimes be omitted.

[0050] <Circuit Structure 10>

[0051] Also Figures 1-3As shown, the circuit structure 10 includes a second heating element, namely a fuse 12, and a first heating element, namely a relay 14, as heating elements that generate heat when energized. Furthermore, the circuit structure 10 includes a current-carrying busbar 16 connected to the connection portions 38 and 44 of the fuse 12 and relay 14 (described later), and a heat-dissipating busbar 18, which is a metal plate, connected to the connection portions 38 and 44 of the fuse 12 and relay 14. The circuit structure 10 includes a housing 24 composed of an upper housing 20 and a lower housing 22, which houses the fuse 12, relay 14, current-carrying busbar 16, and heat-dissipating busbar 18. The heat-dissipating busbar 18 includes a heat-dissipating portion 26, which protrudes through an opening 28 in the housing 24 to the outside of the housing 24, making thermal contact with a metal casing 29, such as the casing of a battery pack, which is the object of heat dissipation. That is, the heat dissipation part 26 being exposed to the outside through the opening 28 of the housing 24 means that the heat dissipation part 26 can make thermal contact with the heat dissipation object outside the housing 24 without passing through the housing 24.

[0052] The circuit structure 10 includes an insulating film 30 that seals the opening 28 and a filler 32 that serves as a heat-conducting filling member. The insulating film 30 covers the contact surface 34 of the heat dissipation section 26 that contacts the outer casing 29 and is fixed to the casing 24. The filler 32 is in thermal contact with the heat dissipation section 26 via the insulating film 30 and is disposed between the insulating film 30 and the outer casing 29. Furthermore, the heat dissipation section 26 is in thermal contact with the outer casing 29 via the insulating film 30 and the filler 32. It should be noted that in Figures 1-3 In the middle, the outer shell 29 is represented by a double-dotted line.

[0053] In Embodiment 1, two relays 14 are arranged side-by-side in the left-right direction, with the left relay 14 being the first relay 14a and the right relay 14 being the second relay 14b. A fuse 12 is disposed to the left of the left-side first relay 14a. Furthermore, four power-conducting busbars 16 are provided, numbered first to fourth power-conducting busbars 16a to 16d from left to right. Additionally, five heat-dissipating busbars 18 are provided, numbered first to fifth heat-dissipating busbars 18a to 18e from left to right. Furthermore, two insulating films 30 are arranged side-by-side in the left-right direction, with the left insulating film 30 being the first insulating film 30a and the right insulating film 30 being the second insulating film 30b.

[0054] <Fuse 12, First and Second Relays 14a, 14b>

[0055] The fuse 12 has a fuse body 36 that is approximately rectangular in shape. Metal connecting portions 38, 38 protruding to the left and right sides are provided on the fuse body 36. Bolt insertion holes 40, 40 extending vertically are formed in the connecting portions 38, 38. In Embodiment 1, the bolt insertion hole 40 on the right side is an elongated hole with a left-right dimension larger than its front-back dimension. This allows for the absorption of assembly errors and tolerances when assembling the current-carrying busbar 16, etc., into the fuse 12.

[0056] The first and second relays 14a and 14b each have a relay body 42, 42 formed in a cuboid shape. A pair of connecting portions 44, 44 are separated from each other in the left-right direction on the front surface of each relay body 42. That is, a total of four connecting portions 44 are provided in the first relay 14a and the second relay 14b, numbered first to fourth connecting portions 44a to 44d from left to right. In summary, the first relay 14a has first and second connecting portions 44a and 44b. Furthermore, the second relay 14b has third and fourth connecting portions 44c and 44d. In addition, partition plates 46 are provided protruding forward between the first connecting portion 44a and the second connecting portion 44b in the first relay 14a, and between the third connecting portion 44c and the fourth connecting portion 44d in the second relay 14b, respectively, to separate them.

[0057] In addition, each relay body 42 has an outwardly protruding mounting portion 48 on both sides in the left-right direction. These mounting portions 48 have bolt through holes 50 that extend in the vertical direction.

[0058] <First to Fourth Power-On Busbars 16a to 16d>

[0059] The first to fourth energizing busbars 16a to 16d are formed by bending metal sheets into a specified shape using stamping or other processes. The material of each energizing busbar 16a to 16d is not limited, but copper or copper alloys, aluminum or aluminum alloys are preferred.

[0060] The first energizing busbar 16a is a component that connects to the left-side connection portion 38 of the fuse 12, and extends integrally in the left-right direction. The left end of the first energizing busbar 16a is an external connection portion 52, and the right end is a fuse connection portion 54. Bolt insertion holes 56 and 58 that extend in the vertical direction corresponding to the plate thickness are formed in the external connection portion 52 and the fuse connection portion 54.

[0061] The second energizing busbar 16b is a component that connects the right-side connecting portion 38 of the fuse 12 to the first connecting portion 44a of the first relay 14a, and extends integrally in the left-right direction. The left end of the second energizing busbar 16b is the fuse connecting portion 60, which has a bolt insertion hole 62 extending in the vertical direction that is the plate thickness direction. Furthermore, the right end of the second energizing busbar 16b is the relay connecting portion 64, which has a bolt insertion hole 66 extending in the front-back direction that is the plate thickness direction.

[0062] The third energizing busbar 16c is a component that connects the second connecting part 44b in the first relay 14a to the third connecting part 44c in the second relay 14b, and extends as a whole in the left-right direction. The left and right ends of the third energizing busbar 16c are relay connecting parts 68, 68, which have bolt insertion holes 70, 70 that extend in the front-back direction in the plate thickness direction. Furthermore, a rectangular external connecting part 72 protruding forward is provided at the upper end of the central part in the left-right direction of the third energizing busbar 16c, which has a bolt insertion hole 74 that extends in the vertical direction in the plate thickness direction.

[0063] The fourth energizing busbar 16d is a component that connects to the fourth connecting portion 44d in the second relay 14b, and extends integrally in the left-right direction. The left end of the fourth energizing busbar 16d is a relay connecting portion 76, which has a bolt insertion hole 78 extending in the front-rear direction in the plate thickness direction. Furthermore, the right end of the fourth energizing busbar 16d has a forward-protruding rectangular external connecting portion 80, which has a bolt insertion hole 82 extending in the vertical direction in the plate thickness direction.

[0064] <First to fifth heat dissipation busbars 18a to 18e>

[0065] The first to fifth heat dissipation busbars 18a to 18e are formed by bending metal sheets into a specified shape using stamping or other processes. The material of each heat dissipation busbar 18a to 18e is not limited, but it can be made of the same material as the power-conducting busbar 16 (the first to fourth power-conducting busbars 16a to 16d).

[0066] The first heat dissipation busbar 18a is a component that connects to the left-side connecting portion 38 of the fuse 12 (second heating element), and extends integrally in the left-right direction. That is, the first heat dissipation busbar 18a in the metal plates (first to fifth heat dissipation busbars 18a to 18e) is a metal plate for the second heating element (fuse 12) that is connected to it. The left end of the first heat dissipation busbar 18a, which is one end, is a heat dissipation portion 26 (first heat dissipation portion 26a), and extends horizontally (XY plane) with a predetermined left-right dimension. Furthermore, the right end of the first heat dissipation busbar 18a, which is the other end, is a fuse connecting portion 84, which serves as a connection point to the connecting portion 38. It is located above the first heat dissipation portion 26a (on the upper housing 20 side) and extends horizontally parallel to the first heat dissipation portion 26a. A bolt through hole 86 is formed in the fuse connecting portion 84, extending in the vertical direction along the plate thickness direction. The first heat dissipation part 26a and the fuse connection part 84 are connected by a connecting part 87 that extends in the vertical direction. The connecting part 87 stands from the right end of the first heat dissipation part 26a toward the left end of the fuse connection part 84.

[0067] The second to fifth heat dissipation busbars 18b to 18e are components that connect to the first to fourth connecting portions 44a to 44d in the first and second relays 14a and 14b (first heating components). That is, the second to fifth heat dissipation busbars 18b to 18e in the metal plate (first to fifth heat dissipation busbars 18a to 18e) are metal plates for the first heating component that connect to the first heating component (first and second relays 14a and 14b). The second to fifth heat dissipation busbars 18b to 18e are each bent into an L-shape as a whole, and each has a heat dissipation portion 26 (second to fifth heat dissipation portions 26b to 26e) extending horizontally in the XY plane at one end. Furthermore, the other end of the second to fifth heat dissipation busbars 18b to 18e is a relay connecting portion 88 that serves as a connection point to the first to fourth connecting portions 44a to 44d. Furthermore, each relay connection portion 88 stands upright from the front end of the second to fifth heat dissipation portions 26b to 26e, facing upwards (towards the upper housing 20). As described later, each relay connection portion 88 is bolted together with the relay connection portions 64, 68, and 76 in the second to fourth energizing busbars 16b to 16d to the first to fourth connection portions 44a to 44d. That is, each relay connection portion 88 is the connection point of the first bolt 132 described later in the second to fifth heat dissipation busbars 18b to 18e.

[0068] Each relay connection portion 88 has a bolt insertion hole 90 extending in the front-rear direction, which is the plate thickness direction. In Embodiment 1, the bolt insertion hole 90 extends in the vertical direction (the assembly direction of the upper housing 20 and the lower housing 22) and is an elongated hole shape with a vertical dimension larger than its horizontal dimension. As described later, the second to fifth recesses 108b to 108e house the second to fifth heat dissipation sections 26b to 26e of the second to fifth heat dissipation busbars 18b to 18e and are positioned in the second to fifth positioning sections 110b to 110e. In this state, the bolt insertion hole 90 can absorb the tolerances of the first to fourth connection portions 44a to 44d in the first and second relays 14a and 14b and the connection portions (relay connection portions 88) in the second to fifth heat dissipation busbars 18b to 18e. Therefore, in Embodiment 1, as one of the tolerance absorption structures provided in the circuit structure 10, the first tolerance absorption structure that absorbs the tolerance of the connection position (relay connection part 88) between the second to fifth heat dissipation busbars 18b to 18e and the first to fourth connection parts 44a to 44d is composed of a bolt insertion hole 90.

[0069] <Upper shell 20>

[0070] The upper shell 20 is made of synthetic resin, and also... Figure 3 As shown, the upper housing 20 is a box-shaped structure that opens downwards as a whole and extends in the left-right direction. Specifically, the upper housing 20 has a generally rectangular top wall 92 that extends as a whole in the left-right direction. A side wall 94 protruding downwards (towards the lower housing 22) is provided on the outer periphery of the top wall 92. Multiple openings 96 extending in the thickness direction (vertical direction) are formed on the top wall 92 at its left and right ends. These openings 96 are located in the first, third, and fourth power-conducting busbars 16a, 16c, and 16d at positions corresponding to external connection portions 52, 72, and 80. Thus, in the assembled circuit structure 10, the external connection portions 52, 72, and 80 are exposed to the outside through the openings 96. Furthermore, multiple openings 98 opening downwards and extending in the thickness direction (front-back direction) are formed on the front portion of the side wall 94. These openings 98 are formed in the first and second relays 14a and 14b at positions corresponding to the first to fourth connecting portions 44a to 44d.

[0071] It should be noted that on the lower surface of the top wall 92, nuts 99 are assembled at positions corresponding to the bolt insertion holes 40 provided in the connection portion 38 of the fuse 12 and the bolt insertion holes 50 provided in the mounting portions 48 of the first and second relays 14a and 14b (see reference). Figure 5In embodiment 1, the upper portion of the nut 99 protrudes outwards, and a claw capable of elastic deformation is provided on the lower surface of the top wall 92. The claw engages with the protruding portion of the nut 99, thereby assembling the nut 99 to the top wall 92. Furthermore, a gap S is provided between the top wall 92 and the nut 99 in the vertical direction (see reference). Figure 5 Nut 99 is assembled to the top wall 92 with a certain degree of looseness. It should be noted that in the initial state before the second bolt 130 (described later) is connected to nut 99, the gap S is at its maximum, and nut 99 is located at the downward displacement end.

[0072] And, as Figure 5 As shown, the connecting portion 38 of the fuse 12, the fuse connecting portion 54 of the first energizing busbar 16a, and the fuse connecting portion 84 of the first heat dissipation busbar 18a coincide with the nut 99. At this time, the nut 99 moves upward (in the direction of separation from the mounting surface 107, described later), thereby absorbing the tolerances of each component. As described later, the first heat dissipation portion 26a of the first heat dissipation busbar 18a is received in the first recess 108a and positioned in the first positioning portion 110a. In this state, the nut 99 can move in the direction of separation from the mounting surface 107, thereby absorbing the tolerance of the connection position between the connecting portion 38 in the fuse 12 and the connecting portion (fuse connecting portion 84) in the first heat dissipation busbar 18a. Therefore, in Embodiment 1, as another tolerance absorption structure provided in the circuit structure 10, a second tolerance absorption structure is formed by having a structure in which the nut 99 can be displaced in the direction of separation from the mounting surface 107 to absorb the tolerance of the connection position between the connection part (fuse connection part 84) and the connection part 38 in the first heat dissipation busbar 18a.

[0073] It should be noted that the method of fixing the nut 99 to the lower surface of the top wall 92 is not limited to the concave-convex fitting described above; it can be welding, bonding, pressing, embedding, etc. In this case, the gap S between the top wall 92 and the nut 99 is not necessary, and the nut 99 can be fixed to the top wall 92 without displacement.

[0074] <Lower shell 22>

[0075] The lower shell 22 is made of synthetic resin, and also... Figure 6As shown, the lower housing 22 is a box-shaped structure that opens upwards as a whole and extends in the left-right direction. Specifically, the lower housing 22 has a generally rectangular bottom wall 100 that extends as a whole in the left-right direction. A peripheral wall 102 protruding upwards is provided at the outer periphery of the bottom wall 100. Multiple upward-protruding support portions 104 are provided on the bottom wall 100 at its left and right ends. These support portions 104 are formed at positions corresponding to the external connection portions 52, 72, and 80 in the first, third, and fourth power-conducting busbars 16a, 16c, and 16d. Thus, in the assembled circuit structure 10, the external connection portions 52, 72, and 80 are supported from below by the support portions 104. Furthermore, a nut 106 is fixed to the upper end of each support portion 104. The method of fixing the nut 106 to the support portion 104 can be the same as the method described above for fixing the nut 99 to the lower surface of the top wall 92.

[0076] In addition, as well as Figure 4 , 5 As shown, the lower housing 22 is mounted on the outer casing 29 via insulating films 30 (first and second insulating films 30a and 30b) and filler 32. Therefore, the lower surface of the bottom wall 100 in the lower housing 22 is a mounting surface 107 for the heat dissipation object (outer casing 29) extending along the horizontal direction (XY plane). Furthermore, as... Figure 7 , 8 As shown, recesses 108 (first to fifth recesses 108a to 108e) are formed on the mounting surface 107 to accommodate the heat dissipation portions 26a to 26e of each heat dissipation busbar 18a to 18e, as described later.

[0077] That is, the first to fifth recesses 108a to 108e, when viewed from above, are approximately equal to or slightly larger than the first to fifth heat dissipation portions 26a to 26e. The first to fifth recesses 108a to 108e are bottomed recesses that open downwards, and the top plate of each recess 108a to 108e is formed by the bottom wall 100 of the lower housing 22. Furthermore, the depth of the first to fifth recesses 108a to 108e is approximately equal to the thickness of the first to fifth heat dissipation portions 26a to 26e. Therefore, as will be described later, when the first to fifth recesses 108a to 108e house the first to fifth heat dissipation portions 26a to 26e, the mounting surface 107 can be flush with the lower surface of the first to fifth heat dissipation portions 26a to 26e.

[0078] Furthermore, in Embodiment 1, the thickness of the bottom wall 100 of the lower housing 22 is approximately constant throughout. Also, in the portions where the recesses 108a to 108e are provided, the upper surface of the bottom wall 100 protrudes upwards from other portions and is recessed towards the upper housing 20 by the depth of each recess 108a to 108e. The portion of the top plate constituting each recess 108a to 108e, located above other portions on the upper surface of the bottom wall 100, is a positioning portion 110 (first positioning portion 110a to fifth positioning portion 110e) that positions the heat dissipation portions 26a to 26e of each heat dissipation busbar 18a to 18e, as described later. Specifically, the first positioning portion 110a is a positioning portion for the second metal plate used to position the second heat-generating component metal plate (first heat dissipation busbar 18a). Furthermore, the second to fifth positioning parts 110b to 110e are positioning parts for the first metal plate used to position the metal plate for the first heating component (the second to fifth heat dissipation busbars 18b to 18e).

[0079] Also Figure 4 , 5 As shown, a through hole 111 extending vertically is provided in the bottom wall 100. The through hole 111 opens to the upper and lower surfaces (mounting surface 107) of the bottom wall 100. Furthermore, in the mounting surface 107, the through hole 111 connects to the recess 108. That is, the bottom wall 100 is provided with first to fifth through holes 111a to 111e that are respectively connected to the first to fifth recesses 108a to 108e. Through the first to fifth recesses 108a to 108e and the first to fifth through holes 111a to 111e, openings 28 (first to fifth openings 28a to 28e) are formed in the mounting surface 107 to expose the first to fifth heat dissipation sections 26a to 26e of the first to fifth heat dissipation busbars 18a to 18e to the outside. In summary, the first to fifth openings 28a to 28e are bottomed openings (first to fifth recesses 108a to 108e) that partially have a bottom (top plate). Furthermore, the remaining portions are bottomless openings that penetrate the bottom wall 100 (first to fifth insertion holes 111a to 111e). In Embodiment 1, the second to fifth insertion holes 111b to 111e are slits with a lateral dimension larger than their longitudinal dimension.

[0080] Specifically, a first through-hole 111a is formed to the right of the first recess 108a. Furthermore, second to fifth through-holes 111b to 111e are formed to the front of the second to fifth recesses 108b to 108e. This first through-hole 111a, when viewed from above (projection in the vertical direction), is larger than the fuse connection portion 84 and the connecting portion 87 in the first heat dissipation busbar 18a. For example... Figure 5As shown, the first through hole 111a has a first region 84a that allows the fuse connection portion 84 in the first heat dissipation busbar 18a to be inserted and a second region 87a that allows the connection portion 87 to be inserted. The second to fifth through holes 111b to 111e are larger than the relay connection portions 88 in the second to fifth heat dissipation busbars 18b to 18e when viewed from above.

[0081] Furthermore, in Embodiment 1, the lower opening of the first through hole 111a has a large opening size, and a cover receiving portion 112 for receiving the cover portion 128 (described later) is formed on the mounting surface 107. Specifically, the opening of the cover receiving portion 112 is larger on the right side and front and rear sides compared to the first through hole 111a, and the left side of the cover receiving portion 112 communicates with the first recess 108a. That is, the cover receiving portion 112 opens downwards and has a bottom portion 114 formed by the bottom wall 100 of the lower housing 22 on the right side and front and rear sides.

[0082] Furthermore, in implementation method 1, as also Figure 8 As shown, on the lower surface (placement surface 107) of the bottom wall 100, a downwardly protruding protrusion 116 is formed around the entire circumference of the first opening 28a. Furthermore, protrusions 116 are formed around the entire circumference of the second to fifth openings 28b to 28e. In Embodiment 1, the plurality of protrusions 116 are arranged separately from each other in the circumferential direction. A gap 118 is formed between adjacent protrusions 116 in the circumferential direction. Particularly in Embodiment 1, the protrusions 116 are triangular in shape when viewed from above (projection in the vertical direction), and are arranged such that their width gradually narrows towards the first opening 28a and the second to fifth openings 28b to 28e located inwards. Therefore, the gap 118 between the protrusions 116 gradually widens from the outside towards the inside. It should be noted that the size of the gap 118 between the protrusions 116 is not limited, but is preferably a size, for example, so that a user's finger cannot be inserted.

[0083] <Shell 24>

[0084] The housing 24 is formed by assembling the upper housing 20 and the lower housing 22 together. In Embodiment 1, the opening of the upper housing 20 is larger than the opening of the lower housing 22, and the upper housing 20 is assembled from above to cover the opening of the lower housing 22 from the outside. That is, in Embodiment 1, the assembly direction of the upper housing 20 and the lower housing 22 is vertical. The method of fixing the upper housing 20 and the lower housing 22 is not limited. For example, recesses and protrusions that fit together can be provided on the upper housing 20 and the lower housing 22, and the upper housing 20 and the lower housing 22 can be fixed together by the interlocking of the recesses and protrusions.

[0085] In Embodiment 1, four opening windows 98 are formed in the front wall portion of the side wall 94 of the upper housing 20. During the assembly of the upper housing 20 and the lower housing 22, the lower openings of the opening windows 98 are closed by the peripheral wall 102 of the lower housing 22. Therefore, a rectangular working hole 120 penetrating in the thickness direction is formed in the housing 24 at the location where the opening windows 98 are formed (see Figure 1). Figure 4 Furthermore, in Embodiment 1, a cap 122 that locks the working hole 120 is installed on the housing 24. In particular, in Embodiment 1, four working holes 120 are provided, but the cap 122 locks two adjacent working holes 120, and two caps 122 are installed on the housing 24.

[0086] The cap 122 has a rectangular flat base plate 124. Multiple claw portions 126 protruding to one side in the thickness direction are provided on the base plate 124. The base plate 124 is aligned with the side wall 94 of the upper housing 20, and the claw portions 126 are engaged with the opening edge of the working hole 120, thereby installing the cap 122 onto the housing 24. Specifically, the claw portions 126 are engaged with the upper and lower opening edges and either the left or right opening edge of the working hole 120. That is, the upper claw portion 126 is engaged with the upper edge of the opening window 98, and the lower claw portion 126 is engaged with the opening edge of the peripheral wall 102 of the lower housing 22.

[0087] Furthermore, in Embodiment 1, the first insertion hole 111a, which opens to the lower surface (placement surface 107) of the housing 24 (lower housing 22), is closed by a rectangular flat cover 128. When viewed from above (projection in the vertical direction), the cover 128 is sized to be larger than the first insertion hole 111a and smaller than the cover receiving portion 112. This causes the outer periphery of the cover 128 to abut against the bottom portion 114 of the cover receiving portion 112, thereby closing the lower opening of the first insertion hole 111a. Specifically, as described later, the fuse connection portion 84 and the connecting portion 87 of the first heat dissipation busbar 18a pass through the first region 84a and the second region 87a of the first insertion hole 111a and insert into the interior of the housing 24 (lower housing 22), and the first heat dissipation portion 26a of the first heat dissipation busbar 18a extends outward from the interior of the housing 24 (lower housing 22) through the connecting portion 87. That is, the cover portion 128 is fixed in such a way that it covers the first region 84a of the first insertion hole 111a.

[0088] The thickness of the cover portion 128 is approximately equal to the depth of the cover portion receiving portion 112 (i.e., the vertical dimension from the mounting surface 107 to the bottom portion 114 of the cover portion receiving portion 112). Thus, as will be described later, when the cover portion 128 is housed in the cover portion receiving portion 112, the lower surfaces of the mounting surface 107 and the first heat dissipation portion 26a are flush with the lower surface of the cover portion 128.

[0089] It should be noted that the cover 128 can be fixed to the cover receiving portion 112 by simply placing the first insulating film 30a on the bottom portion 114 of the cover receiving portion 112 and attaching it from the outside, as described later. Alternatively, for example, a protrusion extending inwards can be provided at the lower opening of the cover receiving portion 112, and the cover 128 can pass over this protrusion and be received in the cover receiving portion 112, thereby maintaining the cover 128 in a received state within the cover receiving portion 112. When removing the cover 128 from the cover receiving portion 112, simply peel off the first insulating film 30a, or after peeling off the first insulating film 30a, allow the protrusion at the lower opening of the cover receiving portion 112 to pass over it. In summary, the cover 128 is fixed to the cover receiving portion 112 provided on the mounting surface 107 in a detachable manner.

[0090] <First and second insulating films 30a, 30b>

[0091] Also Figure 4 , 5 As shown, first and second insulating films 30a and 30b are fixed on the lower surface of the housing 24 (lower housing 22). These first and second insulating films 30a and 30b are formed of a synthetic resin with waterproof and electrical insulating properties and are rectangular in shape. Specifically, as shown... Figure 7 , 8 As shown by the double-dotted line, the first insulating film 30a is formed to cover the size of the first opening 28a. Furthermore, the second insulating film 30b is formed to cover the size of the second to fifth openings 28b to 28e. It should be noted that the thickness of the first and second insulating films 30a and 30b is not limited. The first and second insulating films 30a and 30b are preferably, for example, 500 μm or less, more preferably 250 μm or less. By setting the thickness of the first and second insulating films 30a and 30b to the above range, good heat transfer properties can be achieved. It should be noted that... Figure 4 , 5 In the figure, the thickness of the first and second insulating films 30a and 30b is exaggerated for ease of observation.

[0092] The materials for the first and second insulating films 30a and 30b can be, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE), polycarbonate (PC), polyimide (PI), etc. Specifically, materials such as "Kapton (registered trademark)" manufactured by Toray-DuPont Ltd. can be used.

[0093] In Embodiment 1, the first and second insulating films 30a and 30b, when viewed from above (projection in the vertical direction), cover the entire circumference of the first opening 28a and the second to fifth openings 28b to 28e, respectively; that is, they are larger in both the front-to-back and left-to-right directions. The first insulating film 30a is formed in the lower surface (placement surface 107) of the lower housing 22, converging to the size of the inner side of a plurality of protrusions 116 disposed around the first opening 28a. The second insulating film 30b is formed to converge to the size of the inner side of the plurality of protrusions 116 disposed around the second to fifth openings 28b to 28e. In other words, the plurality of protrusions 116 are arranged around the respective peripheral edges of the first insulating film 30a and the second insulating film 30b. The relative gaps between the first insulating film 30a and the protrusions 116, and between the second insulating film 30b and the protrusions 116, are not limited, but are preferably, for example, sizes that prevent the insertion of a user's finger.

[0094] It should be noted that the method for fixing the first and second insulating films 30a and 30b to the lower surface (placement surface 107) of the downward housing 22 can be, for example, by attaching the first and second insulating films 30a and 30b to the placement surface 107, as they themselves have adhesive surfaces. Alternatively, an adhesive can be applied to at least one of the placement surface 107 (including the lower surfaces of the first to fifth heat dissipation portions 26a to 26e and the lower surface of the cover portion 128) and the first and second insulating films 30a and 30b, and then attached to the placement surface 107. It should be noted that the aforementioned adhesive surfaces and adhesives are preferably provided across the entire surface of the first and second insulating films 30a and 30b. Moreover, in the case where waterproofing is achieved through such an adhesive, the first and second insulating films 30a and 30b themselves may not be waterproof. The method for fixing the first and second insulating films 30a and 30b to the placement surface 107 of the downward housing 22 is not limited, and known methods such as bonding or welding can be used.

[0095] In Embodiment 1, the sizes of the first and second insulating films 30a and 30b are set to be relatively large compared to the first heat dissipation portion 26a and the second to fifth heat dissipation portions 26b to 26e. Specifically, for example, in the second insulating film 30b, the lateral length L of the portion that is pasted to overlap with the lower surface (mounting surface 107) of the lower housing 22 outside the lateral direction of the second to fifth heat dissipation portions 26b to 26e (refer to...) Figure 2 , 8 The length L is set relatively large. The specific length of this dimension L is not limited and can be set to, for example, 11mm to 12mm. As a result, the distance between the second heat dissipation busbar 18b and the edge of the housing 29 can be set to be large, which can prevent accidental electrical short circuits.

[0096] <Packaging 32>

[0097] The filler 32 can be any component that has heat transfer (heat dissipation) properties and fills the space between the housing 24 (lower housing 22) and the first and second insulating films 30a, 30b and the outer shell 29. That is, the first to fifth heat dissipation parts 26a to 26e are in thermal contact with the outer shell 29 through the first and second insulating films 30a, 30b and the filler 32 disposed on the sides of these first and second insulating films 30a, 30b. Therefore, the lower surface of each of the first to fifth heat dissipation parts 26a to 26e is a contact surface 34 that contacts the outer shell 29, and this contact surface 34 is covered by the first and second insulating films 30a, 30b.

[0098] The filler 32 is formed from, for example, a synthetic resin with electrical insulating properties. In Embodiment 1, the filler 32 is separate from the first and second insulating films 30a and 30b, and preferably has, for example, elasticity. This allows it to absorb unevenness caused by the protrusion 116 provided on the lower surface (placement surface 107) of the lower housing 22 and the first and second insulating films 30a and 30b. The filler 32 can be a component commonly referred to as an elastic material or filler, and can be, for example, a conventionally known thermally conductive interface material or a heat-dissipating gap filler. As the filler 32, a composite material, for example, in which a thermally conductive filler is filled into a resin such as epoxy resin or silicone resin, can be used. As the thermally conductive filler filling the resin, for example, alumina, boron nitride, aluminum nitride, silicon nitride, etc., can be used. It should be noted that the thermally conductive filling component can be in various forms, such as sheet, gel, or grease.

[0099] In Embodiment 1, the filler 32 can be a gap filler that is in the form of grease when applied to the lower surface of the lower housing 22 and the lower surfaces of the first and second insulating films 30a and 30b, and which solidifies into a sheet-like form due to heat (e.g., room temperature). Using such a filler 32 advantageously prevents air from entering the lower housing 22, the space between the first and second insulating films 30a and 30b and the filler 32, and the space between the filler 32 and the outer casing 29, thereby improving heat dissipation. For example, the "SDP series" manufactured by Shin-Etsu Chemical Industry Co., Ltd. can be used as such a filler 32. It should be noted that the filler 32 can be a material that exhibits a certain degree of elasticity both before and after assembly.

[0100] As in Embodiment 1, if the filler 32 is, for example, in the form of grease, it is an amorphous shape without a predetermined shape before assembly. Figure 3The image shows a cured rectangular plate-shaped filler 32. The curing of filler 32 is based on heat (e.g., room temperature, a temperature higher or lower than room temperature), such as ultraviolet (UV) light. However, filler 32 is not limited to the above-described manner; it can be formed from materials such as rubber or elastomers, possessing a certain degree of strength in its initial state before assembly, and thus forming a rectangular plate shape. In this case, in the initial state, recesses corresponding to the outer periphery of the lower housing 22, the protrusion 116, and the first and second insulating films 30a and 30b can be pre-formed. It should be noted that the shape of filler 32 (or the shape of cured filler 32) is not limited to a rectangular plate shape.

[0101] In Embodiment 1, the filler 32 is disposed between the lower housing 22 and the outer housing 29, and in a top view, it covers an area wider than the lower housing 22. That is, in Embodiment 1, the placement areas of the first and second insulating films 30a and 30b are different from those of the filler 32. Specifically, in a top view (projection in the vertical direction, i.e., viewing in the direction coinciding with the outer housing 29), the filler 32 is disposed with an area larger than that of the first and second insulating films 30a and 30b.

[0102] Assembly steps for circuit structure 10

[0103] Next, a specific example of the assembly steps for circuit structure 10 will be described. It should be noted that the assembly steps for circuit structure 10 are not limited to the following description.

[0104] First, prepare the upper housing 20, fuse 12, first and second relays 14a and 14b, first to fourth energizing busbars 16a to 16d, and first to fifth heat dissipation busbars 18a to 18e. Then, mount the first and second relays 14a and 14b on the top wall 92 of the upper housing 20 (which is flipped upside down), and connect them to the nut 99 by inserting second bolts 130 into the bolt holes 50 of the mounting portion 48. Thus, the first and second relays 14a and 14b are fixed to the upper housing 20. Furthermore, mount the fuse 12 and the first to fourth energizing busbars 16a to 16d on the top wall 92. Align the bolt hole 40 on the right side of the fuse 12 with the bolt hole 62 of the fuse connection portion 60 in the second energizing busbar 16b, and connect them to the nut 99 by inserting second bolts 130 into these bolt holes 40 and 62.

[0105] Next, the lower housing 22 is assembled from the upper opening of the flipped upper housing 20. The upper housing 20 and the lower housing 22 are fixed together by means of interlocking (not shown). Thus, housing 24 is formed. First to fifth heat dissipation busbars 18a to 18e are assembled onto the bottom wall 100 of the upper lower housing 22. Specifically, the fuse connection portion 84 of the first heat dissipation busbar 18a and the relay connection portion 88 of the second to fifth heat dissipation busbars 18b to 18e are inserted into housing 24 through the first to fifth through holes 111a to 111e provided in the bottom wall 100 of the lower housing 22. At this time, the first to fifth heat dissipation portions 26a to 26e of the first to fifth heat dissipation busbars 18a to 18e are accommodated in the first to fifth recesses 108a to 108e provided in the bottom wall 100 of the lower housing 22. That is, the first to fifth heat dissipation sections 26a to 26e are brought into contact with the first to fifth positioning sections 110a to 110e, thereby positioning the first to fifth heat dissipation busbars 18a to 18e on the lower housing 22. As a result, the mounting surface 107 is flush with the lower surface (which is the upper surface due to the upside-down rotation during assembly) of the first to fifth heat dissipation sections 26a to 26e. Here, the first positioning section 110a in the positioning section 110 (first to fifth positioning sections 110a to 110e) that positions the first heat dissipation busbar 18a (the metal plate for the second heating element) is a positioning section for the second metal plate. Furthermore, the second to fifth positioning sections 110b to 110e in the positioning section 110 (first to fifth positioning sections 110a to 110e) that position the second to fifth heat dissipation busbars 18b to 18e (the metal plate for the first heating element) are positioning sections for the first metal plate.

[0106] Furthermore, fuse connection portion 84 and relay connection portion 88 are inserted into housing 24, thereby aligning fuse connection portion 54 in the first energizing busbar 16a with fuse connection portion 84 in the first heat dissipation busbar 18a in the vertical direction. This aligns the bolt insertion hole 40 on the left side of fuse 12 with the bolt insertion holes 58 and 86 provided in the two fuse connection portions 54 and 84. Additionally, relay connection portions 64, 68, and 76 in the second to fourth energizing busbars 16b to 16d are aligned with relay connection portions 88 in the second to fifth heat dissipation busbars 18b to 18e in the front-back direction. This aligns the bolt insertion holes 66, 70, and 78 in the first to fourth connection portions 44a to 44d of the first and second relays 14a and 14b, and the bolt insertion holes 90 in the relay connection portions 88.

[0107] Then, a second bolt 130 extending in the vertical direction (the assembly direction of the upper housing 20 and the lower housing 22) and a connecting tool (not shown) are inserted through the first through hole 111a. Furthermore, the second bolt 130 is inserted through each of the bolt through holes 40, 58, and 86, which are aligned with each other, and connected to the nut 99. Thus, the fuse 12 is fixed to the upper housing 20, and the first power-conducting busbar 16a and the first heat-dissipating busbar 18a are fastened together to the connection portion 38 of the fuse 12 by bolt connection. Moreover, a first bolt 132 extending in the rearward direction (orthogonal to the assembly direction of the upper housing 20 and the lower housing 22) and a connecting tool (not shown) are inserted through the working hole 120 provided at the front of the housing 24. Furthermore, the first to fourth connecting parts 44a to 44d, which are aligned with each other, and the bolt insertion holes 66, 70, 78, and 90 are connected to the first to fourth connecting parts 44a to 44d by inserting the first bolt 132. Thus, the second to fourth energizing busbars 16b to 16d and the second to fifth heat dissipation busbars 18b to 18e are bolted together and fastened to the first to fourth connecting parts 44a to 44d in the first and second relays 14a and 14b. In this way, the first to fourth energizing busbars 16a to 16d and the first to fifth heat dissipation busbars 18a to 18e are connected to the connecting parts 38, 44a to 44d of the fuse 12 and the first and second relays 14a and 14b.

[0108] After the first bolt 132 is connected, the cap 122 is assembled into the working hole 120 to close the working hole 120, which is an opening in the housing 24. Furthermore, after the second bolt 130 is connected through the first insertion hole 111a, the cover 128 is assembled into the cover receiving portion 112 to close the first insertion hole 111a. It should be noted that the housing 24 is flipped vertically, so even if the cover 128 is only placed on the bottom portion 114 of the cover receiving portion 112, the cover 128 will not fall off the cover receiving portion 112. However, for example, a protrusion for preventing the cover 128 from falling off can be provided at the opening edge of the cover receiving portion 112. The cover 128 can be assembled into the opening edge of the cover receiving portion 112 over this protrusion.

[0109] Next, the first opening 28a is sealed by attaching a first insulating film 30a to the bottom wall 100 of the lower housing 22, covering the first heat dissipation portion 26a and the cover portion 128. Furthermore, the second to fifth openings 28b to 28e are sealed by attaching a second insulating film 30b, covering the second to fifth heat dissipation portions 26b to 26e. Next, filler 32 is applied to the bottom wall 100 of the lower housing 22 and to the first and second insulating films 30a and 30b. Then, the entire assembly is flipped over, thus completing the circuit structure 10 of Embodiment 1.

[0110] In Embodiment 1, the filler 32, before assembly, is in the form of grease. After being applied to the bottom wall 100 of the lower housing 22 and the lower surfaces of the first and second insulating films 30a and 30b, the filler 32 is cured while being pressed against the upper surface of the metal outer casing 29. Thus, the first to fifth heat dissipation portions 26a to 26e come into thermal contact with the outer casing 29 via the first and second insulating films 30a and 30b and the filler 32. Furthermore, by applying the grease-like filler 32 to the housing 24 and curing it while pressing it against the outer casing 29, air is prevented from entering the lower housing 22 and the space between the first and second insulating films 30a and 30b and the filler 32, and between the filler 32 and the outer casing 29. Therefore, in Embodiment 1, with the circuit structure 10 fixed to the outer casing 29, the lower surface of the lower housing 22 is located slightly below the upper surface of the filler 32 (see reference). Figure 4 wait).

[0111] In the circuit structure 10 assembled through the steps described above, the external connection portions 52, 72, and 80 of the first, third, and fourth power-conducting busbars 16a, 16c, and 16d are exposed to the outside through the opening window 96 of the housing 24 (upper housing 20). Then, the terminals of the externally located wires are aligned with the external connection portions 52, 72, and 80, and bolts (not shown) are inserted into the bolt insertion holes 56, 74, and 82 of each external connection portion 52, 72, and 80 to connect them to the nuts 106. Thus, the external wires are electrically connected to the circuit structure 10.

[0112] Furthermore, the fuse 12 and the first and second relays 14a and 14b generate heat when energized. The heat generated by the fuse 12 and the first and second relays 14a and 14b is transferred to the first and fifth heat dissipation sections 26a and 26e in the first to fifth heat dissipation busbars 18a to 18e. This heat is then dissipated to the outside of the first to fifth heat dissipation sections 26a and 26e through the outer casing 29, which is in thermal contact with the first and second insulating films 30a and 30b via the filler 32.

[0113] In the circuit structure 10 of Embodiment 1, the first to fifth heat dissipation portions 26a to 26e of the first to fifth heat dissipation busbars 18a to 18e, which expose the first to fifth openings 28a to the outside of the housing 24, are sealed by the first and second insulating films 30a and 30b. Therefore, even if condensation occurs inside the battery pack, such as the metal housing 29, and water enters the battery pack, it can prevent this water from entering the housing 24 of the circuit structure 10 and causing a short circuit between the first to fifth heat dissipation portions 26a to 26e and the housing 29. Furthermore, by providing the first to fifth openings 28a to 28e in the housing 24, the amount of resin required for the housing 24 can be reduced.

[0114] The lower housing 22 has first to fifth positioning portions 110a to 110e for positioning the first to fifth heat dissipation busbars 18a to 18e. With the first to fifth heat dissipation busbars 18a to 18e positioned in the first to fifth positioning portions 110a to 110e, the lower surface (mounting surface 107) of the lower housing 22 is flush with the lower surfaces of the first to fifth heat dissipation portions 26a to 26e. Therefore, even when the first and second insulating films 30a and 30b are adhered by sealing the first to fifth openings 28a to 28e, it is possible to suppress or prevent the formation of a step between the mounting surface 107 and the lower surfaces of the first to fifth heat dissipation portions 26a to 26e, thus preventing deterioration of the adhesion workability of the first and second insulating films 30a and 30b. In addition, it can also advantageously suppress or prevent the first and second insulating films 30a and 30b from being unable to be flatly fixed to the lower housing 22 due to the steps, and prevent air from being drawn into the first and second insulating films 30a and 30b and the filler 32, resulting in a decrease in heat dissipation.

[0115] In particular, in Embodiment 1, the fuse connection portion 84 and the relay connection portion 88 of the first to fifth heat dissipation busbars 18a to 18e are inserted through the first to fifth through holes 111a to 111e provided in the lower housing 22. Then, the fuse connection portion 84 and the relay connection portion 88 are aligned with the connection portion 38 of the fuse 12, the first and second relays 14a and 14b, and the first to fourth connection portions 44a to 44d. Here, first and second tolerance absorption structures are provided to absorb the tolerance at their connection positions. Therefore, the connection portions 38 of the fuse 12, the first and second relays 14a and 14b, and the first to fourth connection portions 44a to 44d can be stably connected to the fuse connection portion 84 and the relay connection portion 88 of the first to fifth heat dissipation busbars 18a to 18e by bolt connection.

[0116] In embodiment 1, the first and second tolerance absorption structures described above are composed of bolt through holes 90 that are elongated in the vertical direction and structures that allow the nut 99 to be displaced in the vertical direction. Therefore, the tolerance absorption structure can be realized with a simple structure.

[0117] In Embodiment 1, a working hole 120 is provided that penetrates the housing 24 in the thickness direction. Through this working hole 120, the first to fourth connecting portions 44a to 44d of the first and second relays 14a and 14b, the relay connecting portions 64, 68, and 76 of the second to fourth energizing busbars 16b to 16d, and the relay connecting portion 88 of the second to fifth heat dissipation busbars 18b to 18e can be bolted together. This eliminates the need to separately fix the second to fourth energizing busbars 16b to 16d and the second to fifth heat dissipation busbars 18b to 18e to the first and second relays 14a and 14b, thus improving workability. In particular, the relay connecting portion 88 of the second to fifth heat dissipation busbars 18b to 18e has a bolt insertion hole 90 constituting a first tolerance absorption structure, further improving workability.

[0118] The first to fifth positioning portions 110a to 110e, which position the first to fifth heat dissipation busbars 18a to 18e toward the housing 24 (lower housing 22), are formed by a top plate that houses the first to fifth recesses 108a to 108e of the first to fifth heat dissipation portions 26a to 26e of the first to fifth heat dissipation busbars 18a to 18e. That is, with such a simple structure that provides the first to fifth recesses 108a to 108e on the lower surface of the lower housing 22 to house the first to fifth heat dissipation portions 26a to 26e, it is possible to simultaneously achieve the effect of making the mounting surface 107 in the lower housing 22 flush with the lower surface of the first to fifth heat dissipation portions 26a to 26e, and the effect of positioning the first to fifth heat dissipation busbars 18a to 18e.

[0119] When bolting is made to the connection portion (fuse connection portion 84) of the first heat dissipation busbar 18a and the connection portion 38 of the fuse 12, the first insertion hole 111a, into which the second bolt 130 and the connecting tool are inserted, is locked by the cover portion 128. This prevents water from entering through the first insertion hole 111a and prevents accidental contact between the user and the first heat dissipation busbar 18a. Furthermore, it prevents the first insulating film 30a from being punctured after it has been applied, for example, by a user's finger penetrating through the first insertion hole 111a and entering the housing 24. Particularly in Embodiment 1, the lower surfaces of the lower housing 22, the first to fifth heat dissipation portions 26a to 26e, and the cover portion 128 are flush, which advantageously suppresses or prevents the formation of steps. Therefore, the process of attaching the first and second insulating films 30a and 30b can be carried out smoothly. By making the contact surfaces of the first and second insulating films 30a and 30b that contact the filler 32 side flat, the situation where air enters between the first and second insulating films 30a and 30b and the filler 32 and the heat dissipation decreases can be effectively suppressed or prevented.

[0120] Multiple protrusions 116 are provided around the first and second insulating films 30a and 30b that are adhered to the lower surface of the lower housing 22. This reduces the possibility of the first and second insulating films 30a and 30b being accidentally peeled off by the user. Furthermore, the first and second insulating films 30a and 30b are adhered to the inside of these multiple protrusions 116, thus serving as markings for adhering the first and second insulating films 30a and 30b. In addition, gaps 118 are provided between the multiple protrusions 116. Therefore, even when the filler 32 is provided on the lower housing 22 and the lower surfaces of the first and second insulating films 30a and 30b, air between the lower housing 22, the first and second insulating films 30a and 30b, and the filler 32 can be discharged to the outside through the gaps 118. This prevents air from entering between the lower housing 22, the first and second insulating films 30a and 30b, and the filler 32. As a result, the heat generated in the heat-generating components (fuse 12, first and second relays 14a, 14b) can be dissipated stably.

[0121] In particular, the multiple protrusions 116, which are formed in a triangular shape, are arranged such that their width gradually narrows towards the inward side. This ensures that the inner opening size within the gap 118 between the protrusions 116 is large. This allows for more efficient capture and discharge of air forced out by the first and second insulating films 30a and 30b and the filler 32. Furthermore, the outer opening size within the gap 118 between the protrusions 116 is kept small. This further reduces the possibility of accidental contact between the user and the first and second insulating films 30a and 30b.

[0122] In embodiment 1, a heat-conducting filler 32 is provided on the entire lower surface of the lower housing 22 and the lower surfaces of the first and second insulating films 30a and 30b, thereby maintaining good heat dissipation performance and further improving waterproofing.

[0123] <Other Implementation Methods>

[0124] The technology described in this specification is not limited to the embodiments illustrated above and in the accompanying drawings. For example, embodiments such as those described below are also included within the technical scope of the technology described in this specification.

[0125] (1) In the embodiment described above, three heating components (fuse 12, first and second relays 14a and 14b) are provided, but only at least one heating component is required.

[0126] (2) In the described embodiment, the power-conducting busbars 16 (first to fourth power-conducting busbars 16a to 16d) and the heat-dissipating busbars (first to fifth heat-dissipating busbars 18a to 18e) are provided separately, but the power-conducting busbars and the heat-dissipating busbars can also be provided as a single unit. That is, the heat dissipation part can be provided on a metal plate that serves both power conduction and heat dissipation, and the heat dissipation part can be exposed to the outside through an opening provided in the housing, and the opening is sealed by an insulating film.

[0127] (3) The structure of the housing that houses the heating element and the metal plate is not limited to the manner described in the embodiment. For example, the opening of the lower housing may be larger than the opening of the upper housing, and the sidewall of the upper housing may be located inside the peripheral wall of the lower housing. In cases where water may seep in between the upper and lower housings, a conventionally known waterproof structure may be provided between the upper and lower housings.

[0128] (4) In the above embodiment, an opening window 98 for the working hole 120 constituting the front of the housing 24 is provided in the upper housing 20, but it can be as follows: Figure 9 As shown in the circuit structure 140, an upward-opening window 142 is provided on the peripheral wall 102 of the lower housing 144. Furthermore, the working hole 120 can be formed by closing the upper opening of the window 142 through the side wall 94 of the upper housing 146. It should be noted that in the described embodiment or... Figure 9 In the illustrated configuration, the working hole 120 is formed by the lower or upper opening of the downward or upward opening window 98, 142 being closed by the peripheral wall 102 of the lower housing 22 or the side wall 94 of the upper housing 146, but this configuration is not limited to these methods. A working hole penetrating in the thickness direction can be directly formed on the side wall of the upper housing or the peripheral wall of the lower housing, or opening windows can be provided on both the side wall of the upper housing and the peripheral wall of the lower housing, and the working hole can be formed by these opening windows overlapping in the front-rear direction. Furthermore, in Figure 9 In the illustrated configuration, a mounting portion 48 is provided at the lower part of the relay body 42 of the first relay 14a. The first relay 14a is fixed to the lower housing 144 by inserting a second bolt 130 into the bolt through hole 50 of the mounting portion 48. In this way, the heating element or metal plate housed inside the housing can be assembled into the lower housing.

[0129] (5) In the described embodiment, a structure is shown in which the lower housing 22 has a mounting surface 107 and openings 28 (first to fifth openings 28a to 28e) are formed on the mounting surface 107, but this disclosure is not limited to this. For example, it may be a circuit structure having a housing without a lower housing, and a fixing part for fixing to a heat dissipation object is provided on the side wall of the upper housing, and the housing is fixed to the heat dissipation object through the fixing part. In this case, it is self-evident that by fixing the insulating film to the end face of the side wall of the upper housing, the openings of the housing can be sealed by the insulating film, and the same effect of this disclosure can be enjoyed.

[0130] (6) In the embodiment described above, the working hole 120 is locked by a cap 122. However, if the working hole is located above the height of water generated on the outer casing due to factors such as condensation, the cap for locking the working hole may not be necessary. Furthermore, in the embodiment described above, four working holes 120 are provided and two caps 122 are provided to lock two adjacent working holes 120. However, it is also possible to provide four caps to lock each working hole individually, or to provide one cap to lock all four working holes.

[0131] (7) In the described embodiment, a plurality of triangular protrusions 116 are provided around the first and second insulating films 30a and 30b on the lower surface (placement surface 107) of the lower housing 22, but this is not a limitation. The protrusions can be polygonal shapes such as quadrilaterals, or circular shapes (including perfect circles, ellipses, oblongs, semicircles, etc.). Moreover, even in the case of triangular shapes, it is not necessary to narrow from the outside to the inside as in the described embodiment; they can narrow from the inside to the outside. Alternatively, protrusions can be provided around the area covering, for example, 1 / 3 or 1 / 2 of the circumference of the insulating film, or protrusions can be provided around approximately the entire circumference with slit-like gaps on a portion of the circumference. Thus, when the insulating film is applied, air between the lower housing and the insulating film and the filler can escape through the gaps. However, gaps between the protrusions are not necessary, and the protrusions can be continuously provided around the entire circumference of the insulating film. In this case, the anti-peeling effect of the insulating film can be obtained more stably. It should be noted that, in this disclosure, the protrusions provided on the lower surface of the lower housing are not necessary.

[0132] (8) In the described embodiment, the filler 32 is exemplified as having a grease-like form during coating and a sheet-like form after curing, but it is not limited to this embodiment, and conventionally known heat-conducting sheets may also be used. Furthermore, in the described embodiment, the filler 32 is provided in a region wider than the lower surface of the lower housing 22, but the placement area is not limited. The filler may be provided in a region narrower than the lower surface of the lower housing, or it may be provided with a placement area smaller than the insulating film when viewed from above. However, in this disclosure, a heat-conducting filling member (filler 32) is not essential.

[0133] (9) In the described embodiment, the first and second insulating films 30a and 30b are configured to be smaller than the lower surface of the lower housing 22 when viewed from above, and the filler 32, which is separate from the first and second insulating films 30a and 30b, is configured to be larger than the lower surface of the lower housing 22 when viewed from above. However, for example, an insulating film having waterproof and heat-conducting properties may also be configured to be larger than the lower surface of the lower housing. However, such an insulating film only needs to be configured to a size that can at least seal the opening of the housing.

[0134] (10) In the embodiment described above, the second insulating film 30b is a single film that completely covers the second to fifth openings 28b to 28e. However, the second to fifth openings may also be sealed by separate insulating films, for example. Furthermore, in the embodiment described above, two insulating films are provided: a first insulating film 30a that seals the first opening 28a and a second insulating film 30b that seals the second to fifth openings 28b to 28e. However, a single insulating film that completely covers the first to fifth openings may also be provided. It should be noted that in the embodiment described above, the first and second insulating films 30a and 30b are rectangular in shape, but their shapes are not limited, as long as they are large enough to seal the openings of the housing.

[0135] Label Explanation

[0136] 10 Circuit Structure

[0137] 12. Fuses (heating element, secondary heating element)

[0138] 14. Relay (Heating Component, First Heating Component)

[0139] 14a First Relay

[0140] 14b Second Relay

[0141] 16 Busbars for power supply

[0142] 16a First energized busbar

[0143] 16b Second power supply busbar

[0144] 16c Third-hand busbar

[0145] 16d Fourth power supply busbar

[0146] 18. Heat dissipation busbars (metal plate)

[0147] 18a First heat dissipation busbar (second heat-generating component metal plate)

[0148] 18b Second heat dissipation busbar (metal plate for the first heat-generating component)

[0149] 18c Third heat dissipation busbar (metal plate for the first heat-generating component)

[0150] 18d Fourth heat dissipation busbar (metal plate for the first heat-generating component)

[0151] 18e Fifth heat dissipation busbar (metal plate for the first heat-generating component)

[0152] 20 Upper shell

[0153] 22 Lower shell

[0154] 24. Shell

[0155] 26 Heat dissipation section

[0156] 26a First heat dissipation section

[0157] 26b Second heat dissipation section

[0158] 26c Third heat dissipation section

[0159] 26d Fourth heat dissipation section

[0160] 26e Fifth heat dissipation unit

[0161] 28. Opening

[0162] 28a First opening

[0163] 28b Second opening

[0164] 28c Third opening

[0165] 28d Fourth opening

[0166] 28e Fifth opening

[0167] 29. Casing (for heat dissipation)

[0168] 30 Insulating film

[0169] 30a First insulating film

[0170] 30b Second insulating film

[0171] 32. Packing material (heat transfer filling component)

[0172] 34 Contact surface

[0173] 36. Fuse body

[0174] 38 Connecting parts

[0175] 40 Bolt through hole

[0176] 42 Relay body

[0177] 44 Connecting parts

[0178] 44a First connecting part

[0179] 44b Second connecting part

[0180] 44c Third connecting part

[0181] 44d Fourth connecting part

[0182] 46. ​​Divider

[0183] 48 Installation Department

[0184] 50 Bolt through hole

[0185] 52 External connection part

[0186] 54. Fuse connection part

[0187] 56 and 58 bolt through holes

[0188] 60 Fuse Connection

[0189] 62 Bolt through hole

[0190] 64 Relay connection part

[0191] 66 Bolt through hole

[0192] 68 Relay connection part

[0193] 70 Bolt through hole

[0194] 72 External connection part

[0195] 74 Bolt through hole

[0196] 76 Relay connection part

[0197] 78 Bolt through hole

[0198] 80 External Connection Section

[0199] 82 Bolt through hole

[0200] 84. Fuse connection part (connection area)

[0201] 84a First Area

[0202] 86 Bolt through hole

[0203] 87 Connecting parts

[0204] 87a Second Region

[0205] 88 Relay Connection Part (Connection Point)

[0206] 90mm bolt through hole (first tolerance absorption structure)

[0207] 92 Top Wall

[0208] 94 Sidewall

[0209] 96, 98 Open windows

[0210] 99 nuts

[0211] 100 bottom wall

[0212] 102 Zhou Bi

[0213] 104 Support section

[0214] 106 nuts

[0215] 107 Placement Surface

[0216] 108 recess

[0217] 108a first recess

[0218] 108b Second recess

[0219] 108c third recess

[0220] 108d fourth concave part

[0221] 108e fifth recess

[0222] 110 Positioning Department

[0223] 110a First positioning part (positioning part for second metal plate)

[0224] 110b Second positioning part (positioning part for the first metal plate)

[0225] 110c Third Positioning Part (Positioning Part for First Metal Plate)

[0226] 110d Fourth Positioning Section (Positioning Section for First Metal Plate)

[0227] 110e Fifth Positioning Section (Positioning Section for First Metal Plate)

[0228] 111 Through Hole

[0229] 111a First through hole

[0230] 111b Second through hole

[0231] 111c Third Through Hole

[0232] 111d Fourth through hole

[0233] 111e Fifth through hole

[0234] 112 Cover Reception Department

[0235] 114 Bottom part

[0236] 116 protuberance

[0237] 118 gap

[0238] 120 working hole

[0239] 122 hat

[0240] 124 Matrix Plate

[0241] 126 claws

[0242] 128 cover

[0243] 130 Second Bolt

[0244] 132 First Bolt

[0245] 140 Circuit Structure

[0246] 142 Opening window

[0247] 144 Lower housing

[0248] 146 Upper shell

[0249] S gap

Claims

1. A circuit structure, comprising: The heating element heats up when electricity is applied. A metal plate is connected to the connecting part of the heating component and has a heat dissipation part that makes thermal contact with an external heat dissipation object. The housing houses the heating element and the metal plate, and has an opening that exposes the heat dissipation portion of the metal plate to the outside. and An insulating film is used to seal and fix the opening of the housing to the housing. The housing includes an upper housing and a lower housing. The heating element is fixed to at least one of the upper housing and the lower housing. The lower housing has a mounting surface for placing the heat dissipation object, and the opening is provided on the mounting surface. The lower housing has a positioning part that positions the heat dissipation part of the metal plate disposed in the opening flush with the mounting surface. The metal plate is provided with a connecting portion, which is the part where the metal plate connects to the connecting part of the heating element. The circuit structure has a tolerance absorption structure that absorbs the tolerance of the connection position between the connection part and the connection part when the heat dissipation part is positioned by the positioning part.

2. The circuit structure according to claim 1, wherein, The heating element includes a first heating element. The metal plate includes a metal plate for a first heating element, which is connected to the connecting portion of the first heating element. The connecting portion of the first heating element and the connecting portion of the metal plate of the first heating element are connected by a first bolt. The first bolt extends in a direction orthogonal to the assembly direction of the upper shell and the lower shell. An elongated bolt insertion hole is provided at the connecting portion of the metal plate of the first heating element. The bolt insertion hole extends along the assembly direction of the upper shell and the lower shell. The bolt insertion hole constitutes a first tolerance absorption structure, which includes the first tolerance absorption structure.

3. The circuit structure according to claim 2, wherein, The upper housing has a top wall and a side wall, the side wall protruding from the top wall toward the lower housing. The lower housing has a bottom wall and a peripheral wall, the peripheral wall protruding from the bottom wall toward the upper housing. At least one of the side wall and the peripheral wall is provided with a working hole, which allows the first bolt and the tool for connecting the first bolt to be inserted.

4. The circuit structure according to claim 2 or 3, wherein, The first heating element is made of a metal plate bent into an L-shape. One end of the metal plate forms the heat dissipation portion, which extends parallel to the mounting surface of the lower housing. The other end of the metal plate forms the connecting portion that faces the upper housing. The mounting surface of the lower housing is provided with a recess and a slit-shaped insertion hole. The insertion hole allows the connection part to pass through. The recess is connected to the insertion hole and recessed towards the upper housing to accommodate the heat dissipation part. The opening is formed by including the insertion hole and the recess. The top plate of the recess forms a positioning part for the first metal plate. The positioning part for the first metal plate positions the metal plate for the first heating element. The positioning part includes the positioning part for the first metal plate.

5. The circuit structure according to any one of claims 1 to 3, wherein, The heating element includes a second heating element. The metal plate includes a metal plate for a second heating element, which is connected to the connecting portion of the second heating element. The metal plate for the second heating element includes: a heat dissipation portion disposed on one end of the metal plate and extending parallel to the mounting surface of the lower housing; a connecting portion disposed on the other end of the metal plate, located closer to the upper housing than the heat dissipation portion and extending parallel to the heat dissipation portion; and a connecting portion extending from the heat dissipation portion toward the connecting portion. The mounting surface of the lower housing has a through hole and a recess. The through hole allows insertion between the connecting portion and the connecting part. The recess connects to the through hole and recesses towards the upper housing to accommodate the heat dissipation part. The opening is formed by the through hole and the recess. The top plate of the recess forms a positioning part for the second metal plate. This positioning part for the second metal plate positions the metal plate for the second heating element. The positioning part includes the positioning part for the second metal plate. The connection portion is connected to the connection portion of the second heating component by a second bolt, and the nut is held in a direction that allows it to be displaced from the mounting surface of the lower housing, thereby forming a second tolerance absorption structure. The nut is housed in the upper housing and connected to the second bolt. The tolerance absorption structure includes the second tolerance absorption structure.

6. The circuit structure according to claim 5, wherein, The insertion hole has a first area that allows the connection part to be inserted and a second area that allows the connection part to be inserted. The cover is fixed to the mounting surface in a detachable manner, and the cover covers the first area in the insertion hole.

7. The circuit structure according to any one of claims 1 to 3 and 6, wherein, The housing is provided with a plurality of protrusions spaced apart, which are disposed around the periphery of the insulating film.

8. The circuit structure according to claim 7, wherein, The housing includes an upper housing and a lower housing. The plurality of protrusions are triangular in shape in the projection of the upper housing and the lower housing in the assembly direction, and are configured to gradually narrow in width as they move toward the insulating film located on the inner side.

9. The circuit structure according to any one of claims 1 to 3, 6, and 8, wherein, The heat dissipation section comes into contact with the heat dissipation object via a heat-conducting filling member disposed on the side of the insulating film.

Images