Circuit body

Abstract

Disclosed is a circuit body capable of suppressing a damage of a conductor pattern and a mounting part for an electronic component of a flexible printed board due to a displacement of an extended path part of the flexible printed board.　The circuit body comprises busbars 12, 14 which form a current supply path, a flexible printed board 24 which is placed on the busbar 14, electronic components 32 which are mounted across the busbar 14 and the flexible printed board 24, and a fixation component 84 which is fixed to the busbar 12 at one end 88a and to the flexible printed board 24 at the other end 88b, the flexible printed board 24 has an extended path part 68 which extends apart from the busbar 14 and forms a conduction path to another circuit to which the electronic components 32 are to be connected, the extended path part 68 includes a displacement region 74 which is routed in a displaceable manner without coming in contact with other members, and the other end 88b of the fixation component 84 is disposed between a connection part 72, where a mounting part 22 of the flexible printed board 24 is connected to the extended path part 68, and the electronic components 32.

Description

circuit body

[0001] The present disclosure relates to circuitry.

[0002] Conventionally, vehicles such as electric vehicles and hybrid vehicles are equipped with a circuit body that is disposed between two conductive paths and that passes or cuts off current. For example, Patent Document 1 discloses a circuit body that includes a pair of bus bars that form a current path between a power source and a load, a circuit breaker (electronic component) having a pair of power terminals connected to the pair of bus bars, respectively, for passing or cutting off current between the pair of bus bars, and a flexible printed circuit board that is connected to a control terminal of the circuit breaker and that is placed on the bus bars.

[0003] In such a circuit body, the interrupter needs to be connected to a control board on which a control unit that outputs a control signal for controlling the interrupter is mounted. Therefore, in the circuit body of Patent Document 1, the flexible printed circuit board has an extension path part that extends toward the control board away from the bus bar, and the conductor pattern of the flexible printed circuit board to which the control terminal of the interrupter is connected extends to an end of the extension path part and is connected to the control board.

[0004] Japanese Patent Application Laid-Open No. 2016-220277

[0005] However, although the extension path of the flexible printed circuit board is connected to the flexible printed circuit board and the control board at both ends in the extension direction, the portion between them is routed in a manner that allows it to move without contacting other components. Therefore, when the extension path is displaced due to vibrations or other factors while the vehicle is mounted, external forces are applied to the conductor patterns of the flexible printed circuit board and the mounting locations of electronic components mounted across the flexible printed circuit board and the bus bar. As a result, damage such as breaks or cracks may occur in the conductor patterns or the mounting locations, potentially disrupting the electrical connection.

[0006] Therefore, a circuit body is disclosed that can suppress damage to the conductor patterns of the flexible printed circuit board and the mounting portions of electronic components due to displacement of the extension path portion of the flexible printed circuit board.

[0007] The circuit body of the present disclosure includes a bus bar that forms a current path, a flexible printed circuit board including a mounting portion to be placed on the surface of the bus bar, an electronic component mounted across the bus bar and the mounting portion, and a fixing component having one end fixed to the surface of the bus bar and the other end fixed to the surface of the mounting portion, wherein the flexible printed circuit board has an extension path portion that is connected to the mounting portion and extends away from the surface of the bus bar, forming a conduction path to another circuit to which the electronic component is connected, the extension path portion including a displacement region that is arranged to be displaceable without contacting another member, and the other end of the fixing component is located between the electronic component and a connection portion of the flexible printed circuit board between the mounting portion and the extension path portion.

[0008] According to the circuit body of the present disclosure, damage to the conductor patterns of the flexible printed circuit board and the mounting locations of electronic components due to displacement of the extension path portion of the flexible printed circuit board can be suppressed.

[0009] Fig. 1 is a perspective view showing a circuit body according to a first embodiment with a part of the case being see-through. Fig. 2 is a partially exploded perspective view showing a part of the circuit body shown in Fig. 1 in an exploded state. Fig. 3 is an enlarged perspective view showing a main part of the circuit body shown in Fig. 1 with a control board being see-through. Fig. 4 is a plan view of the main part of the circuit body shown in Fig. 3. Fig. 5 is a further enlarged perspective view showing the main part of the circuit body shown in Fig. 3.

[0010] <Description of Embodiments of the Present Disclosure> First, embodiments of the present disclosure will be described. A circuit body of the present disclosure includes: (1) a bus bar forming a current path, a flexible printed circuit board including a mounting portion placed on a surface of the bus bar, an electronic component mounted across the bus bar and the mounting portion, and a fixing component having one end fixed to the surface of the bus bar and the other end fixed to a surface of the mounting portion, wherein the flexible printed circuit board has an extension path portion connected to the mounting portion and extending away from the surface of the bus bar to form a conduction path to another circuit to which the electronic component is connected, the extension path portion including a displacement region arranged to be displaceable without contacting another member, and the other end of the fixing component is disposed between a connection portion of the flexible printed circuit board between the mounting portion and the extension path portion and the electronic component.

[0011] According to the circuit body of the present disclosure, a mounting portion of a flexible printed circuit board is mounted on the surface of a bus bar, and an electronic component is mounted straddling the bus bar and the mounting portion of the flexible printed circuit board. The flexible printed circuit board has an extension path portion that forms a conduction path to another circuit to which the electronic component is connected. The extension path portion has a displacement region that is spaced apart from the surface of the bus bar and arranged to be displaceable without contacting other components. Therefore, the displacement region of the extension path portion is displaced due to vibrations and the like when the circuit body is mounted in a vehicle. The circuit body of the present disclosure includes a fixing component that is fixed straddling the bus bar and the mounting portion of the flexible printed circuit board, one end of the fixing component is fixed to the surface of the bus bar, and the other end of the fixing component is located on the mounting portion of the flexible printed circuit board between the connecting portion of the mounting portion and the extension path portion and the electronic component, and is fixed to the surface of the mounting portion. As a result, even if an external force (e.g., a tensile or compressive force, or a displacement force in a direction away from the busbar) is transmitted from the connecting portion of the flexible printed circuit board to the mounting portion due to displacement of the displacement region of the extension path portion, the other end of the fixing component suppresses the displacement of the mounting portion, thereby suppressing transmission of the external force to the electronic component side rather than the other end. As a result, even in a circuit body having a displaceably routed extension path portion, damage to the conductor pattern of the flexible printed circuit board and the mounting portion of the electronic component mounted across the flexible printed circuit board and the busbar can be suppressed, thereby advantageously maintaining the electrical connection of the circuit body. In particular, because one end of the fixing component is fixed to the surface of the busbar and the other end is fixed to the surface of the mounting portion of the flexible printed circuit board, the fixing force of the fixing component to the busbar can be effectively utilized to ensure the function of suppressing displacement of the mounting portion by the other end of the fixing component. Therefore, with a simple structure, damage to the conductor pattern of the flexible printed circuit board and the mounting portion of the electronic component due to displacement of the extension path portion can be suppressed.

[0012] The fixing part can be configured with any shape and material as long as it can be fixed across the bus bar and the mounting portion of the flexible board. Furthermore, any fixing structure can be adopted for both ends of the fixing part as long as it can be fixed to the bus bar and the flexible printed circuit board. For example, the fixing part may be fixed by adhesive or welding, or may be fixed in a manner that allows electricity to pass through.

[0013] (2) In the above (1), it is preferable that the fixing component is conductive, one end of the fixing component is electrically fixed to a surface of the bus bar, the other end of the fixing component is electrically fixed to a first mounting portion-side conductor pattern exposed on the surface of the mounting portion, and the first mounting portion-side conductor pattern is connected to the other circuit via a first path-side conductor pattern provided on the extending path portion.

[0014] The fixing component is conductive, with one end of the fixing component being electrically connected to the bus bar and the other end being electrically connected to the first-mounting-section-side conductor pattern of the flexible printed circuit board. Therefore, the fixing component can also be used as a current-carrying member. Furthermore, the first-mounting-section-side conductor pattern can be connected to another circuit via the first-path-side conductor pattern provided in the extension path portion. This allows the fixing component to be used to configure additional current-carrying circuits without increasing the number of components. Therefore, the fixing component can be used as a component that forms a current-carrying path between the bus bar and the first-mounting-section-side conductor pattern, or as a path for acquiring potential information about the bus bar. Note that any method, such as soldering or welding, can be used to electrically connect both ends of the fixing component to each other.

[0015] (3) In the above (1) or (2), the fixing component is preferably configured such that both ends of the band plate metal fitting are bent in a crank shape toward one side in the plate thickness direction, with one of the crank-shaped ends forming the one end fixed to the surface of the bus bar and the other forming the other end fixed to the surface of the mounting portion. Because both ends of the fixing component, which are respectively fixed to the surface of the bus bar and the surface of the mounting portion of the flexible printed circuit board, are bent in a crank shape, external forces transmitted from the extension paths of the bus bar and the flexible printed circuit board can be absorbed by deformation of the crank-shaped portion. This improves the fixing component's ability to suppress displacement of the mounting portion. Furthermore, when one end and the other end of the fixing component are electrically connected and fixed to the bus bar and the first mounting portion-side conductor pattern, respectively, the crank-shaped one and other ends prevent solder from spreading to the center of the fixing component. This prevents unexpected solder flow, short circuits, and other problems.

[0016] (4) In the above (2), it is preferable that the busbars include an input busbar and an output busbar that form the current path between two conductive paths, the mounting portion is mounted on a surface of the output busbar, the electronic components form a circuit breaker that passes current between the input busbar and the output busbar, the circuit breaker having an input power terminal mounted on the surface of the input busbar, an output power terminal mounted on the surface of the output busbar, and a control terminal mounted on a second mounting portion-side conductor pattern exposed on the surface of the mounting portion, the one end of the fixing component being fixed to the surface of the input busbar so as to be able to conduct current, and the second mounting portion-side conductor pattern being connected to a control circuit, which is the other circuit, via a second path-side conductor pattern provided on the extension path portion.

[0017] The circuit body of this embodiment is disposed between two conductive paths and can control the conduction / disconnection between them. The second mounting portion conductor pattern, to which the control terminal of the interrupter is connected, is connected to another circuit, a control circuit, via the second path portion-side conductor pattern, and can receive a control signal from the control circuit via the extension path portion, which is separated from the busbar. That is, the control circuit that sends a control signal to the interrupter can be located away from the pair of busbars and the interrupter. This eliminates the need to design the control circuit taking high voltage and high current into consideration, even when the circuit body is used in applications where a large current flows through the busbar, such as when it is disposed between a high-voltage battery and a high-voltage load. Furthermore, one end of the fixing part is electrically connected to the surface of the input-side busbar to which the input-side terminal of the interrupter is mounted, and the other end of the fixing part is connected to another circuit, a control circuit, via the electrically connected first mounting portion-side conductor pattern and the first path portion-side conductor pattern. This allows the control circuit to receive information such as the potential on the input side of the interrupter, thereby improving the control performance of the circuit body by the control circuit.

[0018] The circuit body of this embodiment only needs to be configured so that the first / second path-side conductor patterns provided on the extending path portion of the flexible printed circuit board are connected to the control circuit, and includes both a case in which the control circuit is housed in a case that houses the circuit body, and a case in which the control circuit is connected directly or via a separate conductive path to a control circuit arranged in a different location from the circuit body.

[0019] <Details of Embodiments of the Present Disclosure> Specific examples of the circuit body of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0020] First Embodiment An electrical junction box 10 according to a first embodiment of the present disclosure will be described below with reference to FIGS. 1 to 6 . The electrical junction box 10 is an example of a circuit body. The electrical junction box 10 is disposed between two conductive paths, a high-voltage battery and a high-voltage load, in a vehicle such as an electric vehicle or a hybrid vehicle, to allow or block current flow between them. While the electrical junction box 10 can be disposed in any orientation, in the following description, the up-down, front-rear, and left-right directions refer to the up-down, front-rear, and left-right directions shown in FIG. 1 . In addition, when multiple identical components are illustrated, only some of the components may be designated by reference numerals, and the reference numerals may be omitted for the remaining components.

[0021] <Electrical Junction Box 10> The electrical junction box 10 includes an input bus bar 12 and an output bus bar 14 that form a current path between a power source (e.g., a high-voltage battery) as one of two conductive paths (not shown) and a load (e.g., a high-voltage load) as the other of the two conductive paths. The electrical junction box 10 also includes a flexible printed circuit (FPC) 24 including a mounting portion 22 mounted on a surface 18 of the output bus bar 14, and a circuit breaker 32 that is an electronic component mounted across the input bus bar 12, the output bus bar 14, and the mounting portion 22 of the FPC 24. The circuit breaker 32 includes a drain terminal 26 that is an input power terminal mounted on the surface 16 of the input bus bar 12, a source terminal 28 that is an output power terminal mounted on the surface 18 of the output bus bar 14, and a control terminal 30 that is mounted on a conductor pattern (a second mounting portion-side conductor pattern 80 described later) exposed on a surface 23 of the mounting portion 22. The interrupter 32 allows and interrupts current between the input bus bar 12 and the output bus bar 14 .

[0022] In the first embodiment, a case 34 is provided to house the input bus bar 12, the output bus bar 14, the control board 20, the FPC 24, and the interrupter 32. In the first embodiment, the case 34 includes an upper case 36 and a lower case 38. In the first embodiment, a drain-side end bus bar 40 is connected to the input bus bar 12, and a source-side end bus bar 42 is connected to the output bus bar 14. The drain-side end bus bar 40 has an end opposite to the end connected to the input bus bar 12 that protrudes outside the case 34 as a drain-side external connection portion 44. The source-side end bus bar 42 has an end opposite to the end connected to the output bus bar 14 that protrudes outside the case 34 as a source-side external connection portion 46. The drain-side and source-side external connection portions 44, 46 each have a through-hole 47 extending therethrough in the thickness direction.

[0023] <Input-Side Bus Bar 12> The input-side bus bar 12 is a generally E-shaped flat metal plate made of a metal with excellent electrical conductivity, such as copper (including copper alloys) or aluminum (including aluminum alloys). In the first embodiment, as shown in Fig. 4 , the E-shaped opening of the input-side bus bar 12 faces forward. That is, a connecting portion 48 extending in the left-right direction is provided at the rear of the input-side bus bar 12, and drain-side connecting portions 50 to which the aforementioned drain terminals 26 are connected extend forward from both left-right ends and the left-right center of the connecting portion 48.

[0024] In other words, the input bus bar 12 is provided with drain-side connection portions 50 extending in the front-rear direction at both left-right ends and the left-right center, and the rear ends of the drain-side connection portions 50 are connected by the connecting portions 48. The input bus bar 12 also has front openings 52 that open forward between the drain-side connection portions 50 at both left-right ends and the left-right center. The drain-side end bus bar 40 is fixed to the connecting portions 48 of the input bus bar 12 by, for example, welding. The drain-side external connection portions 44 of the drain-side end bus bar 40 are connected to a power source wire, bus bar, or the like (not shown) with or without using the through holes 47.

[0025] <Output-Side Bus Bar 14> The output-side bus bar 14, which is the other of the pair of bus bars, is a generally U-shaped metal plate made of a metal with excellent electrical conductivity, such as copper (including copper alloys) or aluminum (including aluminum alloys). In the first embodiment, as shown in Fig. 4, the U-shaped opening of the output-side bus bar 14 faces rearward. That is, a connecting portion 54 extending in the left-right direction is provided at the front of the output-side bus bar 14, and source-side connecting portions 56 to which the aforementioned source terminals 28 are connected extend rearward from both left-right ends of the connecting portion 54.

[0026] In other words, the output-side bus bar 14 is provided with source-side connection portions 56 extending in the front-rear direction at both left-right ends, and the front ends of the source-side connection portions 56 are connected by the connecting portion 54. A rear opening 58 that opens rearward is formed in the center of the output-side bus bar 14 in the left-right direction. The source-side end bus bar 42 described above is fixed to the connecting portion 54 of the output-side bus bar 14 by, for example, welding. The source-side external connection portions 46 of the source-side end bus bar 42 are connected to a load-side electric wire, bus bar, or the like (not shown) with or without using the through-holes 47.

[0027] The input busbar 12 and the output busbar 14 have approximately the same thickness, and when fixed onto the adhesive sheet 60 and bottom plate 62 described below, the height positions (vertical positions) of the surface 16 of the input busbar 12 and the surface 18 of the output busbar 14 are approximately the same.

[0028] The input busbar 12 and the output busbar 14 are adhered to a metal bottom plate 62 via, for example, a substantially rectangular adhesive sheet 60. The input busbar 12 and the output busbar 14 are arranged on the adhesive sheet 60 so as to face each other in the front-to-rear direction, with the output busbar 14 provided in front of the adhesive sheet 60 and the input busbar 12 provided behind the adhesive sheet 60. The drain-side connection portion 50 at the center of the input busbar 12 in the left-to-right direction is located within a rear opening 58 in the output busbar 14. Furthermore, each source-side connection portion 56 at both left-to-right ends of the output busbar 14 is located within each front opening 52 in the input busbar 12. As a result, the drain-side connection portions 50 and the source-side connection portions 56 are alternately arranged in the left-to-right direction in the middle of the adhesive sheet 60 in the front-to-rear direction. The drain-side connection portions 50 and the source-side connection portions 56 face each other at a predetermined distance in the left-to-right direction.

[0029] The adhesive sheet 60 preferably has insulating and thermally conductive properties, and a conventionally known thermally conductive sheet can be used, for example. Examples of materials that can be used for the adhesive sheet 60 include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE), polycarbonate (PC), and polyimide (PI). Specifically, the adhesive sheet 60 is made of a synthetic resin with a thermal conductivity greater than that of air. Specifically, silicone-based resins, non-silicone acrylic resins, and ceramic resins can be used. More specifically, examples of materials that can be used include heat-dissipating gap fillers, thermally conductive grease, and thermally conductive silicone rubber, all made of silicone-based resins. In the first embodiment, the adhesive sheet 60 is in a sheet shape, but this is not limiting and any shape can be used.

[0030] The bottom plate 62 is formed to a size that covers a lower opening 108 of the lower case 38, which will be described later, and is fixed to the lower case 38 with screws 64. By making the bottom plate 62 out of metal, heat generated in the circuit breaker 32 and the like can be dissipated through the input and output bus bars 12, 14, the adhesive sheet 60, the bottom plate 62, and, for example, a metal housing (not shown) on which the electrical junction box 10 is placed. Note that if the bottom plate 62 is made of synthetic resin, the adhesive sheet 60 does not need to be provided, and the input and output bus bars 12, 14 and the bottom plate 62 can be fixed by a conventionally known fixing method, such as bolt fixing.

[0031] <Flexible Printed Circuit (FPC 24)> A mounting portion 22 of the FPC 24, which is a flexible printed circuit, is mounted on the surface 18 of the output bus bar 14. As shown in Fig. 4 , conductor patterns (first mounting portion-side conductor pattern 90 and second mounting portion-side conductor pattern 80), which will be described later, are printed on the surface 23 of the mounting portion 22 of the FPC 24, and these conductor patterns (first mounting portion-side conductor pattern 90 and second mounting portion-side conductor pattern 80) are exposed on the surface 23 of the mounting portion 22.

[0032] In the first embodiment, a pair of FPCs 24, 24 are provided, and each FPC 24 is generally strip-shaped. One longitudinal end of each FPC 24 is placed on a corresponding source-side connection portion 56 of the output bus bar 14 and fixed thereto by adhesive or the like. In the first embodiment, a mounting portion 22 provided on one longitudinal side of each FPC 24 is overlapped and fixed over substantially the entire surface of each source-side connection portion 56. A generally rectangular through-hole 66 is formed in the mounting portion 22 of each FPC 24, corresponding to the position of the source terminal 28 in the interrupter portion 32. In the first embodiment, since a plurality of interrupters 32 are provided as described below, a plurality of through-holes 66 are formed in the mounting portion 22 of each FPC 24, and the surface 18 of the output bus bar 14 is partially exposed through these through-holes 66.

[0033] Further, an extension path portion 68 is provided at the longitudinal intermediate portion of each FPC 24, connecting to the mounting portion 22 and extending away from the surface 18 of the output-side bus bar 14, to form a conductive path to the control board 20 that constitutes a control circuit to which the control terminal 30 of the interrupter 32 is connected. The extension path portion 68 is arranged curved with the other longitudinal end folded back upward with respect to the mounting portion 22 of each FPC 24 mounted on each source-side connection portion 56. A connection portion 70 is provided at the extending end of each extension path portion 68, which is the other longitudinal end of each FPC 24, and is conductively connected to a control circuit (not shown) provided on the control board 20. At each connection portion 70, the extending end side of each extension path portion 68 of each FPC 24 is conductively connected and fixed to the control board 20. In each extension path portion 68 of each FPC 24, a first path portion side conductor pattern 92 and a second path portion side conductor pattern 82 are printed and formed, extending continuously to each connection portion 70 and continuing from a first mounting portion side conductor pattern 90 and a second mounting portion side conductor pattern 80, respectively, as described below, and are exposed on the surface of each extension path portion 68.

[0034] In this way, the extension path 68 of each FPC 24 defines a displacement region 74 extending from a connecting portion 72 between the mounting portion 22 and the extension path 68, which is the boundary between the mounting portion 22 and the extension path 68, to a connection portion 70 fixed to the control board 20, which is arranged to be displaceable without contacting other members. The displacement region 74 is fixed at both ends in the length direction without contacting other members, and is arranged in a curved manner with an excess length to allow for flexural deformation. Therefore, the displacement region 74 of the extension path 68 is arranged in a state where it can be displaced by vibrations, etc. when mounted on a vehicle.

[0035] <Interrupter 32> Interrupters 32 that conduct and interrupt current between the input bus bar 12 and the output bus bar 14 are connected to the drain connection portion 50 of the input bus bar 12 and the source connection portion 56 of the output bus bar 14. In the first embodiment, the interrupter 32 is a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), which is a power semiconductor. In the first embodiment, a plurality of interrupters 32 are provided across the drain connection portion 50 and the source connection portion 56 that face each other at a predetermined distance in the left-right direction, and these multiple interrupters 32 are arranged in parallel in the front-rear and left-right directions.

[0036] Each interrupter 32 has a drain terminal 26 as an input power terminal, and a source terminal 28 and a control terminal 30 as output power terminals. The drain terminal 26, the source terminal 28, and the control terminal 30 are provided to protrude outward from a substantially rectangular block-shaped main body 31 that constitutes the interrupter 32. Note that, because a conventionally known power MOSFET can be used as each interrupter 32, a description of the specific structure of the main body 31 will be omitted.

[0037] In each interrupter 32, the drain terminal 26 is formed of a roughly plate-shaped terminal fitting, which forms a wide area on the bottom surface (lower surface) of the main body 31 and protrudes outward from the main body 31 (for example, in the direction of the arrow indicating left in each interrupter 32 arranged in the bottom row in Figure 4).

[0038] In the first embodiment, the source terminal 28 in each circuit breaker 32 includes a plurality of terminal fittings 76. The terminal fittings 76 constituting the source terminal 28 protrude outward from the main body 31, opposite the drain terminal 26 (for example, in the direction of the arrow pointing right in the circuit breaker 32 arranged in the bottom row in FIG. 4 ), and the plurality of terminal fittings 76 are arranged in parallel. For example, in FIG. 4 , six terminal fittings 76 are arranged side by side in the direction of the arrow indicating the front-to-rear direction. The shape of each terminal fitting 76 is not limited, but in the first embodiment, each terminal fitting 76 is gull-wing shaped, bent into a substantially L-shape, and each terminal fitting 76 has a vertical portion 78 extending vertically from its longitudinal intermediate portion. That is, each terminal fitting 76 protrudes outward from its vertical intermediate portion of the main body 31, passes through the vertically extending vertical portion 78, and then extends from its protruding tip in the same direction as the direction of protrusion from the main body 31.

[0039] Furthermore, the control terminals 30 in the interrupter 32 are arranged in parallel with the terminal fittings 76 that constitute the source terminals 28. For example, the interrupters 32 arranged in the bottom row in Fig. 4 are arranged forward of the terminal fittings 76 in the direction of the forward arrow. The shape of the control terminals 30 is not limited, but in the first embodiment, they have the same shape as the terminal fittings 76 that constitute the source terminals 28, and are provided with vertical portions 78 that extend vertically in the middle of their length. As a result, like the terminal fittings 76, the control terminals 30 also protrude outward from the middle of the main body 31 in the vertical direction, pass through the vertically extending vertical portions 78, and extend at their protruding tips in the same direction as the protruding direction from the main body 31.

[0040] In each of the cutoff sections 32 having such a shape, the drain terminal 26 is mounted on the surface 16 of the input bus bar 12 at each of the drain connection sections 50. Specifically, the bottom surface (lower surface) of each of the drain terminals 26 and the surface 16 of the input bus bar 12 at each of the drain connection sections 50 are overlapped and electrically connected via solder (not shown).

[0041] Furthermore, the bottom surface (lower surface) of each source terminal 28 in each interrupter 32 is superimposed on the FPC 24 on each source-side connection portion 56 of the output bus bar 14. A through-hole 66 is provided in the FPC 24 on each source-side connection portion 56 at a position corresponding to the source terminal 28 (each terminal fitting 76), exposing the surface 18 of the output bus bar 14. The bottom surface (lower surface) of each terminal fitting 76 in each interrupter 32 is inserted through the through-hole 66 and superimposed on the surface 18 of the output bus bar at each source-side connection portion 56, and is electrically connected via solder (not shown).

[0042] Furthermore, each control terminal 30 in each cutoff unit 32 is overlapped with the mounting portion 22 of the FPC 24 mounted on each source-side connecting portion 56. At the overlapping portion of the control terminal 30 in the mounting portion 22 of the FPC 24, a second mounting portion-side conductor pattern 80 is provided exposed on the surface 23 of the mounting portion 22 of the FPC 24, and the control terminal 30 is electrically connected to the second mounting portion-side conductor pattern 80 via solder (not shown). Furthermore, the second mounting portion-side conductor pattern 80 is connected to a second path portion-side conductor pattern 82 formed exposed on the surface of the extending path portion 68 of the FPC 24. This allows the control terminal 30 of the cutoff unit 32 to be conductively connected to a control circuit (not shown) provided on the control board 20 via the second mounting portion-side conductor pattern 80 and the second path portion-side conductor pattern 82, enabling a control signal from the control circuit to be transmitted to the cutoff unit 32 via the control terminal 30. In this way, by utilizing the extension path portion 68 of the FPC 24 that is separated from the input bus bar 12 and the output bus bar 14, the control board 20 that is provided with a control circuit that sends a control signal to the circuit breaker 32 can be disposed away from the input bus bar 12, the output bus bar 14, and the circuit breaker 32. As a result, even when a large current flows through the input bus bar 12 or the output bus bar 14 of the electrical junction box 10, the control circuit does not need to be designed with high voltage and high current in mind, thereby improving the degree of freedom in designing the control circuit.

[0043] Although detailed description will be omitted, the mounting portion 22 and the extending path portion 68 of the FPC 24 may be provided with other conductor patterns that are electrically connected to the control board 20 as necessary.

[0044] <Fixing Part 84> As shown enlarged in FIG. 5 , the electrical junction box 10 of this embodiment further includes a fixing part 84, one end of which is fixed to the surface 16 of the input bus bar 12 and the other end of which is fixed to the surface 23 of the mounting portion 22 of the FPC 24. The fixing part 84 is formed from a metal strip made of, for example, copper (including copper alloys) or aluminum (including aluminum alloys), which have excellent electrical conductivity. Both ends of the metal strip are bent in a crank-like manner to one side in the thickness direction to form a generally gate-like shape. Specifically, both sides of the metal strip are bent at approximately right angles in the same direction in the thickness direction to form legs 86 on both longitudinal sides. The tip ends of both legs 86 are bent at approximately right angles so as to protrude away from each other, forming a pair of fixing parts 88 a, 88 b at both ends of the fixing part 84. That is, one of the crank-shaped end portions forms one fixing part 88 a, and the other of the end portions forms the other fixing part 88 b.

[0045] A fixing portion 88 a, which is one end of the fixing component 84, is electrically connected to the surface 16 of the input bus bar 12 by, for example, soldering or welding. A fixing portion 88 b, which is the other end of the fixing component 84, is electrically connected via solder (not shown) to a first mounting portion-side conductor pattern 90 exposed on the surface 23 of the mounting portion 22 of the FPC 24. The first mounting portion-side conductor pattern 90 is connected to a first path portion-side conductor pattern 92 exposed on the surface of the extending path portion 68 of the FPC 24. This allows the fixing component 84 to provide potential information on the input bus bar 12 side, on which the drain terminal 26 of the breaker 32, to which the fixing portion 88 a of the fixing component 84 is electrically connected, to a control circuit provided on the control board 20 via the first mounting portion-side conductor pattern 90 and the first path portion-side conductor pattern 92, to which the fixing portion 88 b of the fixing component 84 is electrically connected. As a result, it is possible to improve the control performance of the control circuit for the electrical junction box 10. Here, the position of the fixing component 84 is set so that the fixing portion 88b, which is the other end of the fixing component 84, is located between the connecting portion 72 between the mounting portion 22 of the FPC 24 and the extension path portion 68, and the cutoff portion 32, which is an electronic component located adjacent to the connecting portion 72. By arranging the fixing component 84 in this position, the fixing component 84 can advantageously suppress or prevent displacement due to vibration of the extension path portion 68, which will be described later, from being transmitted to the mounting portion 22.

[0046] <Case 34> Although the specific shape of the case 34 is not limited, in the first embodiment, the case 34 has a generally rectangular box shape as a whole, and as described above, the case 34 is configured to include an upper case 36 and a lower case 38. The case 34 (upper case 36 and lower case 38) may be formed of, for example, a synthetic resin.

[0047] The upper case 36 has a generally flat plate shape or a downwardly opening box shape with a generally rectangular upper bottom wall 94. The lower case 38 has a generally rectangular cylindrical shape with an annular peripheral wall 96. Bus bar support portions 98 are provided on both sides of the inner peripheral surface of the peripheral wall 96 in the front-to-rear direction. The outward extending portions of the drain-side end bus bar 40 and the source-side end bus bar 42 are placed on these bus bar support portions 98, so that the drain-side external connection portions 44 and the source-side external connection portions 46 protrude outward in the front-to-rear direction from the case 34.

[0048] Furthermore, board support portions 100 are provided on both left and right sides of the inner peripheral surface of the peripheral wall 96. These board support portions 100 are provided at two locations on each of the left and right sides, spaced apart in the front-to-rear direction, and the control board 20, to which the connection portions 70 provided at the upper ends of the extension path portions 68 of each FPC are connected, is placed and supported on each board support portion 100 at four locations on the outer peripheral edge. This allows the control board 20 to be positioned above and spaced apart from each of the blocking portions 32 located below without coming into contact with them.

[0049] The upper case 36 then covers the upper opening 102 of the lower case 38, and the peripheral wall 96 of the lower case 38 and the upper case 36 are fixed together in an appropriate manner. In this embodiment, locking claws 104 protruding from multiple circumferentially spaced locations on the outer surface of the peripheral wall 96 engage with locking portions 106 provided at multiple circumferentially spaced locations on the upper case 36, thereby fixing the upper case 36 to the lower case 38. Furthermore, the bottom plate 62, to which the drain and output bus bars 12, 14, the FPCs 24, the circuit breakers 32, etc. are attached, is placed over the lower opening 108 of the lower case 38 and fixed with screws 64, as described above. This completes the case 34.

[0050] <Assembly Process of Electrical Junction Box 10> Next, a specific example of the assembly process of the electrical junction box 10 will be described. Note that the assembly process of the electrical junction box 10 is not limited to the following description.

[0051] First, the drain and output busbars 12, 14 are fixed to the bottom plate 62 via an adhesive sheet 60. Then, the FPCs 24, each having a through hole 66 formed therein, are placed on the source connection portions 56 of the output busbar 14 and fixed thereto, for example, with an adhesive. The interrupters 32 are then positioned so as to span the drain connection portions 50 of the input busbar 12 and the source connection portions 56 of the output busbar 14 (i.e., the FPCs 24 thereon). This allows the drain terminals 26 of each interrupter 32 to overlap the drain connection portions 50. The terminal fittings 76 constituting the source terminals 28 of each interrupter 32 are placed on the surface 18 of the source connection portions 56 through the through holes 66 in the FPCs 24. Furthermore, the control terminals 30 of each interrupter 32 are placed on the second mounting portion-side conductor patterns 80 exposed on the surface 23 of the mounting portion 22 of each FPC 24.

[0052] Next, the fixing component 84 is placed in the above-mentioned position for the fixing component 84, and the fixing portion 88a of the fixing component 84 is superimposed on the surface 16 of the drain-side connection portion 50 located at the bottom of the input-side bus bar 12 in Figure 5. The fixing portion 88b of the fixing component 84 is superimposed on the first mounting portion-side conductor pattern 90 of the mounting portion 22 of the FPC 24. As a result, the fixing portion 88b of the fixing component 84 is superimposed on the surface of the first mounting portion-side conductor pattern 90, with the fixing portion 88b being positioned between the connecting portion 72 between the mounting portion 22 of the FPC 24 and the extension path portion 68, and the blocking portion 32, which is an electronic component positioned adjacent to the connecting portion 72.

[0053] Then, the overlapping portions, i.e., the drain terminals 26 and the drain-side connecting portions 50 (input-side bus bars 12), the terminal fittings 76 constituting the source terminals 28 and the source-side connecting portions 56 (output-side bus bars 14), the control terminals 30 and the second mounting portion-side conductor pattern 80, the fixing portion 88a of the fixing component 84 and the lower drain-side connecting portion 50 (input-side bus bars 12), and the fixing portion 88b of the fixing component 84 and the first mounting portion-side conductor pattern 90, are soldered together to establish electrical continuity for mounting. Note that the soldering method may be a conventionally known method such as reflow soldering.

[0054] Thereafter, the bottom plate 62, to which the input bus bars 12, output bus bars 14, FPCs 24, circuit breakers 32, and fixing parts 84 are attached as described above, is secured to the lower case 38 with screws 64 so as to cover the lower opening 108. Next, the drain and source end bus bars 40, 42 are inserted through the upper opening 102 of the lower case 38 and placed on the bus bar supports 98. The lower ends of the drain and source end bus bars 40, 42 are also fixed to the connecting portions 48, 54 of the drain and output bus bars 12, 14, respectively.

[0055] Next, the extending path portions 68 of each FPC 24 are folded upward, and the connection portions 70 provided at the ends of the folded extending path portions 68 are electrically fixed to the control board 20, and the first path portion-side conductor patterns 92 and the second path portion-side conductor patterns 82 on each FPC 24 are electrically connected to the control circuit on the control board 20. Then, this control board 20 is placed on each board support portion 100 of the lower case 38. Finally, the upper opening 102 of the lower case 38 is covered with the upper case 36, and the upper case 36 and the lower case 38 are fixed together by locking the locking claws 104 and the locking portions 106 together, thereby completing the electrical junction box 10.

[0056] In the electrical junction box 10 assembled as described above, for example, when the connector 110 provided on the control board 20 is connected to an external device and a disconnection signal for the current path is transmitted from the outside, the disconnection signal is transmitted to the control terminal 30 of each disconnecting unit 32 through the control circuit on the control board 20 and the second path portion-side conductor pattern 82 and the second placement portion-side conductor pattern 80 on each FPC 24. When a disconnection voltage based on the disconnection signal is applied to the control terminal 30, the current path is interrupted in each disconnecting unit 32, and the electrical connection between the input-side bus bar 12 and the output-side bus bar 14 is severed. Note that a microcomputer or the like that outputs a disconnection signal may be mounted on the control board 20, and the disconnection signal may be output by the microcomputer and transmitted to each disconnecting unit 32 in response to a disconnection command input from the outside via the connector 110.

[0057] According to the electrical junction box 10 of the first embodiment, a mounting portion for an FPC 24 is mounted on the surface 18 of the output bus bar 14, and the FPC 24 has a circuit breaker 32, which is an electronic component mounted across the input bus bar 12, the output bus bar 14, and the mounting portion for the FPC 24. The FPC 24 has an extension path 68 that forms a conductive path to a control board 20 on which a control circuit connected to the circuit breaker 32 is formed. The extension path 68 is routed between a connecting portion 72 with the mounting portion 22 and a connection portion 70 fixed to the control board 20, separated from the surface 18 of the output bus bar 14 and displaceable without contacting other components, and this portion forms a displacement region 74. This displacement region 74 is subject to displacement due to vibrations, etc., when the FPC 24 is mounted in a vehicle. In contrast, the electrical connection box 10 of embodiment 1 is provided with a fixing component 84 made of a conductive material, and one end of the fixing component 84, which is a fixing portion 88a, is fixed to the surface 16 of the input side bus bar 12 in a manner allowing electrical conduction therebetween, and the other end, which is a fixing portion 88b, is disposed on the mounting portion 22 of the FPC 24, between the connecting portion 72, which is the boundary portion between the mounting portion 22 and the extension path portion 68, and the adjacently disposed interrupting portion 32, and is fixed to the second mounting portion side conductor pattern 80 exposed on the surface 23 of the mounting portion 22 in a manner allowing electrical conduction therebetween.

[0058] As a result, even if the displacement region 74 of the extension path portion 68 is displaced due to vibration of the displacement region 74, and an external force (e.g., a tensile or compressive force, or a force that displaces the mounting portion 22 of the FPC 24 in a direction separating the mounting portion 22 of the FPC 24 from the surface 18 of the output bus bar 14) is transmitted to the mounting portion 22 side from the connecting portion 72 between the mounting portion 22 of the FPC 24 and the extension path portion 68, the fixing portion 88b of the fixing component 84 suppresses the displacement of the mounting portion 22 side. This makes it possible to suppress transmission of the external force to the blocking unit 32 side from the fixing portion 88b of the fixing component 84. Therefore, even if the extension path portion 68 has a displaceably routed displacement region 74, damage to the conductor patterns including the first and second mounting portion-side conductor patterns 90, 80 of the FPC 24 and the mounting portion of the blocking unit 32 mounted across the FPC 24, the input bus bar 12, and the output bus bar 14 can be suppressed. This advantageously maintains the electrical connection state of the electrical junction box 10. In particular, because one fixing portion 88a of the fixing component 84 is electrically fixed to the surface 16 of the input bus bar 12 and the other fixing portion 88b is electrically fixed to the second mounting portion-side conductor pattern 80 exposed on the surface 23 of the mounting portion 22 of the FPC 24, the fixing force of the fixing component 84 to the input bus bar 12 can be effectively utilized to ensure the function of the other fixing portion 88b of the fixing component 84 in suppressing displacement of the mounting portion 22. As a result, with a simple structure, damage to the conductor patterns of the FPC 24 and the mounting portion of the interrupter 32 due to displacement of the displacement region 74 of the extension path portion 68 can be suppressed.

[0059] Furthermore, in the electrical junction box 10 of the first embodiment, the fixing component 84 is conductive and is used as a current-carrying member that electrically connects the input bus bar 12 and the first mounting portion-side conductor pattern 90. The first mounting portion-side conductor pattern 90 is connected to the control circuit of the control board 20 via the first path portion-side conductor pattern 92 provided on the extension path portion 68, so that the fixing component 84 can be used to configure a further current-carrying circuit without increasing the number of components. In the first embodiment, the fixing component 84 is used as a path for acquiring potential information of the input bus bar 12.

[0060] Additionally, the fixing component 84 has both ends of the band plate metal fitting bent in a crank shape toward one side in the plate thickness direction. The fixing component 84 has one fixing portion 88a and the other fixing portion 88b, each bent in a crank shape, and is configured generally gate-shaped overall. Therefore, external forces transmitted from the input bus bar 12 and the extension path portion 68 of the FPC 24 can be absorbed by deformation of the crank-shaped fixing portions 88a and 88b. This improves the function of the fixing component 84 in suppressing displacement of the mounting portion 22. In particular, in the first embodiment, the fixing portions 88a and 88b of the fixing component 84 are fixed by soldering, and the crank-shaped fixing portions 88a and 88b prevent solder from spreading to the center portion of the fixing component 84. This prevents unexpected solder flow, short circuits, and other problems.

[0061] In the first embodiment, the busbars constituting the current-carrying path include an input busbar 12 and an output busbar 14, and a fixing part 88a, which is one end of a fixing component 84, is electrically fixed to the surface 16 of the input busbar 12. A fixing part 88b, which is the other end of the fixing component 84, is electrically fixed to a first mounting portion-side conductor pattern 90, which is connected to another circuit, a control circuit, via a first path portion-side conductor pattern 92. Furthermore, a circuit breaker 32 is employed as an electronic component for passing and breaking current between the input busbar 12 and the output busbar 14. An input power terminal (drain terminal 26) of the circuit breaker 32 is mounted on the input busbar 12, and an output power terminal (source terminal 28) of the circuit breaker 32 is mounted on the output busbar 14. The control terminal 30 is mounted on the second mounting portion-side conductor pattern 80, which is connected to the control circuit via the second path portion-side conductor pattern 82. By employing such a configuration, it is possible to provide the control circuit with information such as the potential of the input side of the breaker 32, thereby improving the control performance of the circuit body (electrical junction box 10) by the control circuit.

[0062] <Modifications> Although the first embodiment has been described above in detail as a specific example of the present disclosure, the present disclosure is not limited to this specific description. Modifications, improvements, etc. within the scope of achieving the object of the present disclosure are included in the present disclosure. For example, the following modifications of the embodiment are also included in the technical scope of the present disclosure.

[0063] (1) In the first embodiment, the fixing component 84 is used as a current-carrying member that electrically connects the input bus bar 12 and the first mounting portion-side conductor pattern 90. However, this is not limiting. For example, the fixing component 84 may be made of an insulating material, and may be fixed with an adhesive or the like across the bus bar and the mounting portion of the flexible printed circuit board to suppress displacement of the mounting portion.

[0064] (2) The electronic components employed in the circuit body of the present disclosure are not limited to the illustrated interrupter 32, but may be any electronic components mounted across the bus bar and the mounting portion of the flexible printed circuit board.

[0065] (3) In the first embodiment, the electrical junction box 10 is shown in which the control board 20 constituting the other circuit to which the extension path 68 of the FPC 24 is connected is housed in the same case, but the other circuit to which the extension path 68 is connected does not have to be housed in the same case. The circuit body of the present disclosure only needs to have the extension path 68 connected to the other circuit, and includes, for example, a case in which the extension path 68 is connected to a control board disposed outside the electrical junction box 10 via a wire harness.

[0066] (4) The fixing part 84 may have any shape as long as it can be fixed across the bus bar and the mounting portion of the flexible printed circuit board. It is not limited to the illustrated shape, and may have a straight plate shape or a curved shape that is curved in an arc or ohmic shape.

[0067] (5) Any fixing structure can be used for both ends of the fixing component as long as it can be fixed to the bus bar and the flexible printed circuit board. For example, in the case of a fixing component used as a current-carrying member, the method is not limited to soldering as shown in the example, and welding or other methods may be used as long as they allow a current-carrying connection. Furthermore, in the case of a fixing component made of a non-current-carrying member, any fixing structure suitable for the material of the fixing component, such as bonding with an adhesive, can be used.

[0068] (6) The shapes, numbers, and protruding directions of the drain terminal 26, source terminal 28, and control terminal 30 of the cutoff portion 32 from the main body portion 31 are not limited to those illustrated, and can be provided in any shape, number, and protruding direction.

[0069] REFERENCE SIGNS LIST 10 Electrical junction box (circuit body) 12 Input bus bar 14 Output bus bar 16 Surface (input bus bar) 18 Surface (output bus bar) 20 Control board (control circuit) 22 Mounting portion 23 Surface (mounting portion) 24 FPC (flexible printed circuit board) 26 Drain terminal (input power terminal) 28 Source terminal (output power terminal) 30 Control terminal 31 Main body portion (breaker portion) 32 Breaker portion 34 Case 36 Upper case 38 Lower case 40 Drain side end bus bar 42 Source side end bus bar 44 Drain side external connection portion 46 Source side external connection portion 47 Through hole 48 Connecting portion 50 Drain side connection portion 52 Front opening 54 Connecting portion 56 Source side connection portion 58 Rear opening 60 Adhesive sheet 62 Bottom plate 64 Screw 66 Through hole 68 Extension path portion 70 Connection portion 72 Linking portion 74 Displacement region 76 Terminal metal fitting 78 Vertical portion 80 Second mounting portion side conductor pattern 82 Second path portion side conductor pattern 84 Fixing part 86 Leg portions 88a, 88b Fixing portion 90 First mounting portion side conductor pattern 92 First path portion side conductor pattern 94 Upper bottom wall 96 Peripheral wall 98 Bus bar support portion 100 Board support portion 102 Upper opening 104 Locking claw 106 Locking portion 108 Lower opening 110 Connector

Claims

1. A circuit body comprising: a busbar forming a current path; a flexible printed circuit board including a mounting portion to be placed on a surface of the busbar; an electronic component mounted straddling the busbar and the mounting portion; and a fixing component having one end fixed to the surface of the busbar and the other end fixed to a surface of the mounting portion, wherein the flexible printed circuit board has an extension path portion connected to the mounting portion and extending away from the surface of the busbar, forming a conduction path to another circuit to which the electronic component is connected, the extension path portion including a displacement region which is arranged to be displaceable without contacting another member, and the other end of the fixing component is disposed between a connection portion of the flexible printed circuit board between the mounting portion and the extension path portion and the electronic component.

2. The circuit body according to claim 1, wherein said fixing part is conductive, said one end of said fixing part is electrically fixed to a surface of said bus bar, and said other end of said fixing part is electrically fixed to a first mounting portion side conductor pattern exposed on the surface of said mounting portion, and said first mounting portion side conductor pattern is connected to said other circuit via a first path side conductor pattern provided on said extending path portion.

3. A circuit body as described in claim 1 or claim 2, wherein the fixing part is configured by bending both end portions of a band plate fitting into a crank shape to one side in the plate thickness direction, one of the crank-shaped both end portions forming the one end that is fixed to the surface of the bus bar, and the other of the crank-shaped both end portions forming the other end that is fixed to the surface of the mounting portion.

4. The circuit body according to claim 2, wherein the busbars include an input side busbar and an output side busbar which form the current path between two conductive paths, the mounting portion is mounted on the surface of the output side busbar, the electronic components form a circuit breaker which passes and cuts off current between the input side busbar and the output side busbar, the circuit breaker having an input side power terminal mounted on the surface of the input side busbar, an output side power terminal mounted on the surface of the output side busbar, and a control terminal mounted on a second mounting portion side conductor pattern exposed on the surface of the mounting portion, the one end of the fixing component is fixed to the surface of the input side busbar so as to be capable of conducting current, and the second mounting portion side conductor pattern is connected to a control circuit which is the other circuit via a second path side conductor pattern provided on the extension path portion.

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