Circuit body

Abstract

Disclosed is a circuit body that, when a blocking section is installed on a pair of busbars and a conductor pattern of a printed board mounted on the busbars, enables suppression of tilting of the blocking section.　The circuit body is provided with: a pair of busbars 12, 14 that form an energization route between two conductive paths; a printed board 24 which is mounted on at least one of surfaces 16, 18 of the pair of busbars 12, 14 and in which a conductor pattern 21, connected to a control circuit, is exposed to a board surface 22; and a blocking section 32 that includes a pair of power terminals 26, 28 installed respectively on the surfaces 16, 18 of the pair of busbars 12, 14 and a control terminal 30 installed on the conductor pattern 21, and that performs conduction and blocking of electricity between the pair of busbars 12, 14. At least one of the pair of power terminals 26, 28 has a mounting section 80 that is mounted on the board surface 22 of the printed board 24.

Description

circuit body

[0001] The present disclosure relates to circuitry.

[0002] Conventionally, vehicles such as electric vehicles and hybrid vehicles are equipped with an electrical junction box that is disposed between a high-voltage battery and a high-voltage load to pass or cut off current. For example, Patent Document 1 discloses an electrical junction box that includes a pair of bus bars that form a current path between a power source and the load, and a breaker unit that is mounted on the pair of bus bars and is formed of a power semiconductor that passes or cuts off current between the bus bars.

[0003] Japanese Patent Application Laid-Open No. 2016-220277

[0004] However, in the structure of Patent Document 1, a pair of power terminals (drain terminal and source terminal) of the circuit breaker are mounted on a pair of bus bars, respectively, and a control terminal (gate terminal) of the circuit breaker is mounted on a conductor pattern of a flexible printed circuit board placed on the bus bar. Therefore, the circuit breaker is mounted at an angle due to a difference in height between the control terminal and the pair of power terminals when mounted, which could result in a connection failure due to misalignment of the control terminal from the conductor pattern.

[0005] Therefore, a circuit body is disclosed that can suppress the inclination of the interrupter when the interrupter is mounted on a pair of bus bars and a conductor pattern of a printed circuit board placed on the bus bars.

[0006] The circuit body of the present disclosure comprises a pair of bus bars that form a current path between two conductive paths; a printed circuit board that is placed on at least one of the surfaces of the pair of bus bars and has a conductor pattern connected to a control circuit exposed on the surface of the board; a pair of power terminals that are mounted on the surfaces of the pair of bus bars, respectively; a control terminal that is mounted on the conductor pattern; and a circuit breaker that passes current between and cuts off current between the pair of bus bars, wherein at least one of the pair of power terminals has a mounting portion that is mounted on the surface of the printed circuit board.

[0007] A circuit body according to another aspect of the present disclosure includes a pair of bus bars that form a current path between two conductive paths; a printed circuit board that is placed on at least one surface of the pair of bus bars and has a conductor pattern connected to a control circuit exposed on the surface of the board; and a circuit breaker that includes a pair of power terminals mounted on the surfaces of the pair of bus bars, respectively, and a control terminal mounted on the conductor pattern, and that passes and cuts off current between the pair of bus bars, wherein a housing portion of a main body of the circuit breaker forms a mounting portion that is placed on the board surface of the printed circuit board.

[0008] According to the circuit body of the present disclosure, it is possible to suppress tilting of the interrupting portion when the interrupting portion is mounted on a pair of bus bars and a conductor pattern of a printed circuit board placed on the bus bars.

[0009] FIG. 1 is a perspective view of a circuit body according to a first embodiment, with a portion of the case being see-through. FIG. 2 is a partially exploded perspective view of a portion of the circuit body shown in FIG. 1 in an exploded state. FIG. 3 is an enlarged perspective view of a main portion of the circuit body shown in FIG. 1, with a control board being see-through. FIG. 4 is a plan view of the main portion of the circuit body shown in FIG. 3. FIG. 5 is a further enlarged perspective view of the main portion of the circuit body shown in FIG. 3. FIG. 6 is a perspective view of a breaker unit constituting the circuit body shown in FIG. 1, with a main body being see-through. FIG. 7 is an enlarged perspective view of a main portion of a circuit body according to a second embodiment, corresponding to FIG. 5. FIG. 8 is an enlarged perspective view of a main portion of a circuit body according to a third embodiment, corresponding to FIG. 3. FIG. 9 is a further enlarged perspective view of a main portion of the circuit body shown in FIG. 8, corresponding to FIG. 5. FIG. 10 is an enlarged perspective view of a main portion of a circuit body according to a fourth embodiment, corresponding to FIG. 5.

[0010] <Description of Embodiments of the Present Disclosure> First, embodiments of the present disclosure will be described below. A circuit body of the present disclosure includes: (1) a pair of bus bars forming a current path between two conductive paths; a printed circuit board mounted on at least one surface of the pair of bus bars and having a conductor pattern connected to a control circuit exposed on the board surface; and a circuit breaker that connects and cuts off current between the pair of bus bars, the circuit breaker including a pair of power terminals mounted on the surfaces of the pair of bus bars, respectively, and a control terminal mounted on the conductor pattern, and at least one of the pair of power terminals has a mounting portion that is mounted on the board surface of the printed circuit board.

[0011] According to the circuit assembly of the present disclosure, a pair of power terminals of the circuit breaker are mounted on the surfaces of a pair of bus bars, respectively, and a control terminal of the circuit breaker is mounted on a conductor pattern exposed on the surface of a printed circuit board mounted on at least one of the surfaces of the pair of bus bars and positioned above the pair of bus bars. At least one of the pair of power terminals has a mounting portion that is mounted on the surface of the printed circuit board. This makes it possible to suppress tilting of the circuit breaker when mounted on the pair of bus bars and the conductor pattern, which is caused by the difference in height between the surfaces of the conductor pattern and the pair of bus bars, compared to when only the control terminal is mounted on the printed circuit board. In other words, in conventional structures, the number of terminals mounted on the bus bars at a lower height is greater than the number of terminals mounted on the conductor patterns at a higher height, which means that the circuit breaker is likely to be pulled toward the bus bars during mounting, potentially causing tilting of the circuit breaker so that the control terminal side rises. According to the present disclosure, at least one of the pair of power terminals has a mounting portion that is mounted on the surface of the printed circuit board at a higher height than the pair of bus bars. Therefore, the area that is held at the same height as the printed circuit board during mounting is increased, and tilting of the interrupter during mounting can be suppressed compared to conventional structures.

[0012] The mounting portion only needs to be provided on at least one of the pair of power terminals, and can be provided in any desired position and shape depending on the routing path of the bus bar and conductor.

[0013] (2) In the above (1), it is preferable that one of the pair of power terminals is connected to one of the pair of bus bars connected to one of the two conductive paths, the other of the pair of power terminals is connected to the other of the pair of bus bars connected to the other of the two conductive paths, the other of the pair of power terminals is configured to include a plurality of terminal fittings, at least one of the terminal fittings forms the mounting portion placed on the surface of the substrate, and the other of the terminal fittings is mounted on the other of the pair of bus bars.

[0014] In some cases, a circuit breaker, such as a power semiconductor, has a power terminal, such as a source terminal, mounted on the other bus bar connected to the other of the two conductive paths, and the other power terminal is configured with multiple terminal fittings, e.g., gull-wing shaped. In this case, at least one of the multiple terminal fittings can be advantageously used to configure a mounting portion to be placed on the surface of a printed circuit board. In particular, when a large current flows through a pair of bus bars, multiple terminal fittings are used to ensure a conductive path, thereby reducing conduction resistance. By utilizing the existing structure of such a circuit breaker, a mounting portion can be easily provided without requiring any design changes to the circuit breaker.

[0015] (3) In the above (2), it is preferable that at least one of the terminal fittings constituting the mounting portion is connected to the conductor pattern. By further connecting at least one of the terminal fittings used in the mounting portion to the conductor pattern of the printed circuit board, it is possible to send information such as the potential of the interrupter to an external control circuit and use it as control information for the vehicle. This further adds value to the use of the mounting portion.

[0016] (4) In the above (2) or (3), it is preferable that at least one of the terminal fittings constituting the mounting portion is not connected to the conductor pattern. Since the at least one terminal fitting used in the mounting portion is a so-called dummy terminal that is not connected to the conductor pattern of the printed circuit board, the selection of the at least one terminal fitting to be used as the mounting portion is not limited by the routing location of the conductor pattern. This has the advantage of allowing for the advantageous selection of a terminal fitting positioned to more effectively correct the inclination of the interrupter portion during installation. For example, by selecting the terminal fitting located farthest from the control terminal as the mounting portion, the inclination of the interrupter portion during installation can be more effectively suppressed.

[0017] (5) In any one of (2) to (4) above, it is preferable that the terminal fittings are arranged in parallel with the control terminals, and the mounting portion is configured to include the terminal fittings that are furthest from the control terminals in the parallel direction. By configuring the mounting portion to include the terminal fittings that are furthest from the control terminals in the parallel direction among the terminal fittings arranged in parallel with the control terminals, tilting of the interrupter during mounting can be more reliably suppressed.

[0018] (6) In any one of the above (2) to (5), it is preferable that the printed circuit board is placed on the surface of the other of the pair of bus bars, the surface of the other of the pair of bus bars is partially exposed through a through hole provided in the printed circuit board, the control terminal mounted on the conductor pattern and at least one of the terminal fittings constituting the mounting portion are placed around the through hole in the printed circuit board, and other terminal fittings are mounted on the surface exposed through the through hole. By providing a through hole in the printed circuit board to expose the surface of the other bus bar, it is possible to mount terminal fittings on the other bus bar near the conductor pattern and to place terminal fittings constituting the mounting portion on the surface of the board, and the configuration of the present disclosure can be realized while suppressing an increase in size.

[0019] (7) In any one of (1) to (6) above, it is preferable that one of the pair of power terminals is connected to one of the pair of bus bars connected to one of the two conductive paths, and the other of the pair of power terminals is connected to the other of the pair of bus bars connected to the other of the two conductive paths, one of the power terminals includes a flat terminal fitting, a part of the flat terminal fitting forms the mounting portion placed on the surface of the substrate, and another part of the flat terminal fitting is mounted on one of the pair of bus bars.

[0020] In some cases, a circuit breaker, which is formed of a power semiconductor or the like, uses a flat terminal as one of its power terminals, such as a drain terminal, mounted on one bus bar connected to one of two conductive paths. In this case, a mounting portion to be placed on the surface of the printed circuit board can be advantageously configured by extending a portion of the flat terminal toward the printed circuit board and / or by extending the printed circuit board toward the flat terminal. In particular, the flat terminal is often disposed on the underside of the case of the circuit breaker. By cleverly utilizing the dead space on the underside of the case, the mounting portion can be easily and space-efficiently provided simply by extending a portion of the flat terminal toward the printed circuit board or by extending the printed circuit board toward the flat terminal.

[0021] A circuit body according to another aspect of the present disclosure (8) includes: a pair of bus bars forming a current path between two conductive paths; a printed circuit board placed on at least one surface of the pair of bus bars and having a conductor pattern connected to a control circuit exposed on the surface of the board; and a circuit breaker that includes a pair of power terminals respectively mounted on the surfaces of the pair of bus bars and a control terminal mounted on the conductor pattern, and that passes and cuts off current between the pair of bus bars, wherein a housing portion of a main body of the circuit breaker forms a mounting portion that is placed on the board surface of the printed circuit board.

[0022] According to the circuit body of this aspect, the housing portion of the main body of the interrupter constitutes a mounting portion that is placed on the surface of the printed circuit board. Therefore, as in the above-mentioned aspect (1), the area that is held at the height of the printed circuit board during mounting is increased, thereby making it possible to suppress tilting of the interrupter during mounting compared to conventional structures.

[0023] <Details of the embodiment 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.

[0024] 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.

[0025] <Electrical Junction Box 10> The electrical junction box 10 includes a pair of bus bars (a drain-side bus bar 12 and a source-side bus bar 14) that are arranged at approximately the same height and 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 board (hereinafter referred to as FPC) 24 that is mounted on at least one of the surfaces (a drain-side surface 16 and a source-side surface 18) of the pair of bus bars (the drain-side bus bar 12 and the source-side bus bar 14) and that has a conductor pattern 21 (shown by a two-dot chain line in FIG. 5 ) exposed on a board surface 22 and connected to a control circuit (not shown) provided on a control board 20. Furthermore, the electrical junction box 10 includes a pair of power terminals (drain terminal 26 and source terminal 28) mounted on the surfaces (drain side surface 16 and source side surface 18) of the pair of bus bars (drain side bus bar 12 and source side bus bar 14), respectively, a control terminal 30 mounted on the conductor pattern 21, and a circuit breaker 32 that passes and cuts off current between the pair of bus bars (drain side bus bar 12 and source side bus bar 14).

[0026] In the first embodiment, a case 34 is provided to house a pair of bus bars (the drain-side bus bar 12 and the source-side 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 drain-side bus bar 12, and a source-side end bus bar 42 is connected to the source-side bus bar 14. The end of the drain-side end bus bar 40 opposite to the end connected to the drain-side bus bar 12 protrudes outside the case 34 as a drain-side external connection portion 44. The end of the source-side end bus bar 42 opposite to the end connected to the source-side bus bar 14 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.

[0027] <Drain-Side Bus Bar 12> The drain-side bus bar 12, which is one of the pair of bus bars, is a generally E-shaped metal plate and is 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 drain-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 drain-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.

[0028] In other words, the drain-side busbar 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 drain-side busbar 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 busbar 40 is fixed to the connecting portions 48 of the drain-side busbar 12 by, for example, welding. The drain-side external connection portions 44 of the drain-side end busbar 40 are connected to a power supply wire, bus bar, or the like (not shown) with or without using the through-holes 47.

[0029] <Source-Side Bus Bar 14> The source-side bus bar 14, which is the other of the pair of bus bars, is a generally U-shaped metal plate and is formed from 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 source-side bus bar 14 is disposed so as to face rearward. That is, a connecting portion 54 extending in the left-right direction is provided at the front of the source-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.

[0030] In other words, the source-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 source-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 source-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.

[0031] The drain side bus bar 12 and the source side bus bar 14 have approximately the same thickness, and when fixed onto the adhesive sheet 60 and the bottom plate 62 described below, the height positions (vertical positions) of the drain side surface 16 and the source side surface 18 are approximately the same.

[0032] The drain-side busbars 12 and source-side busbars 14 are adhered to a metal bottom plate 62 via, for example, a substantially rectangular adhesive sheet 60. The drain-side busbars 12 and source-side busbars 14 are arranged on the adhesive sheet 60 so as to face each other in the front-to-rear direction, with the source-side busbar 14 provided in front of the adhesive sheet 60 and the drain-side busbar 12 provided behind the adhesive sheet 60. A drain-side connection portion 50 at the center of the drain-side busbar 12 in the left-to-right direction is arranged in a rear opening 58 of the source-side busbar 14. Furthermore, source-side connection portions 56 at both left-to-right ends of the source-side busbar 14 are arranged in each front opening 52 of the drain-side busbar 12. Thus, the drain-side connection portions 50 and 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 source-side connection portions 56 face each other at a predetermined distance in the left-to-right direction.

[0033] 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.

[0034] The bottom plate 62 is formed to a size that covers a lower opening 92 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 drain-side and source-side bus bars 12, 14, the adhesive sheet 60, and the bottom plate 62, and then through 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 drain-side and source-side bus bars 12, 14 and the bottom plate 62 can be fixed by a conventionally known fixing method, such as bolt fixing.

[0035] <Printed Circuit Board (FPC 24)> An FPC 24 serving as a printed circuit board is mounted on the surface (source-side surface 18) of the source-side bus bar 14, which is the other of the pair of bus bars. A conductor pattern 21 is printed on a board surface 22 of the FPC 24, and this conductor pattern 21 is exposed on the board surface 22.

[0036] In the first embodiment, a pair of FPCs 24, 24 is 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 source-side bus bar 14 and fixed thereto by adhesive or the like. In the first embodiment, one longitudinal end 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 portion of each FPC 24 that overlaps with the corresponding source-side connection portion 56, corresponding to the position of the source terminal 28 in the interrupter 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 each FPC 24, and the source-side surface 18 of the source-side bus bar 14 is partially exposed through these through-holes 66.

[0037] Each FPC 24 has a folded portion 68 at its longitudinal middle, with the other longitudinal end of the FPC 24 folded upward relative to the one longitudinal end of the FPC 24 placed on each source-side connection portion 56. A control board 20, on which a control circuit (not shown) is printed, is fixed to the other longitudinal end of each FPC 24, and the conductor patterns 21 on each FPC 24 are electrically connected to the control circuit on the control board 20. A connector 70 is mounted on the control board 20, and the control circuit on the control board 20 is electrically connected to the connector 70. When the electrical junction box 10 is assembled, the connector 70 is exposed to the outside through an opening 72 provided in the case 34. When an external device (not shown) is connected to the connector 70, signals from the external device are transmitted to the cutoff portion 32 via the control circuit on the control board 20 and the conductor patterns 21 on each FPC 24.

[0038] <Interrupter 32> Interrupters 32 that pass and interrupt current between the drain-side bus bar 12 and the source-side bus bar 14 are connected to the drain-side connection portions 50 of the drain-side bus bar 12 and the source-side connection portions 56 of the source-side 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-side connection portions 50 and the source-side connection portions 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.

[0039] As shown in Fig. 6 , each interrupter 32 includes a drain terminal 26, which is one of a pair of power terminals, and a source terminal 28 and a control terminal 30, which are the other of the pair of 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 74 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 74 will be omitted. For ease of understanding, Fig. 6 shows the main body 74 in a see-through manner.

[0040] The drain terminal 26, which is one of the power terminals in each circuit breaker 32, includes a generally plate-shaped flat terminal fitting 75. This drain terminal 26 (flat terminal fitting 75) forms a wide area on the bottom surface (lower surface) of the main body 74 and protrudes outward from the main body 74 (for example, in the direction of the arrow pointing right in each circuit breaker 32 shown in FIG. 6 ).

[0041] In the first embodiment, the source terminal 28, which is the other power terminal of 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 74 on the opposite side from the drain terminal 26 (e.g., in the direction of the arrow pointing left in each circuit breaker 32 shown in FIG. 6 ), and these terminal fittings 76 are arranged in parallel. For example, in FIG. 6 , six terminal fittings 76 are arranged side by side in the direction of the arrow pointing forward and backward. 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 the vertical intermediate portion of the main body 74, 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 74 (in the direction of the arrow pointing left in each circuit breaker 32 shown in FIG. 6 ).

[0042] Furthermore, the control terminal 30 in the interrupter 32 is arranged in parallel with the terminal fittings 76 that constitute the source terminal 28, and is arranged further rearward than the terminal fittings 76 in each interrupter 32 in FIG. 6 , for example. The shape of the control terminal 30 is not limited, but in the first embodiment, it has the same shape as the terminal fittings 76 that constitute the source terminal 28, and is provided with a vertical portion 78 extending vertically in the middle of its length. As a result, like the terminal fittings 76, the control terminal 30 also protrudes outward from the middle of the main body 74 in the vertical direction, passes through the vertically extending vertical portion 78, and extends at its protruding tip in the same direction as the protruding direction from the main body 74.

[0043] In each of the cutoff portions 32 having such a shape, each drain terminal 26 is mounted on the surface (drain-side surface 16) of each drain-side connection portion 50 of the drain-side busbar 12. Specifically, the bottom surface (lower surface) of each drain terminal 26 and the drain-side surface 16 of each drain-side connection portion 50 are overlapped and electrically connected via solder (not shown).

[0044] Furthermore, the bottom surface (lower surface) of each control terminal 30 in each interrupter 32 is superimposed on the FPC 24 on each source-side connection portion 56 of the source-side 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 metal fitting 76), exposing the source-side surface 18 of the source-side bus bar 14. The bottom surface (lower surface) of each terminal metal fitting 76 in each interrupter 32 is inserted through the through hole 66 and superimposed on the source-side surface 18 of each source-side connection portion 56, and is electrically connected via solder (not shown).

[0045] 5 and other figures, in the first embodiment, of the six terminal fittings 76, five terminal fittings 76a that are not adjacent to the control terminal 30 are connected to the source-side connection portions 56 through the through-holes 66 in the FPC 24. The remaining terminal fitting 76b that is adjacent to the control terminal 30 is mounted on the FPC 24 without being connected to the source-side connection portion 56. That is, in the first embodiment, the terminal fitting 76b that is adjacent to the control terminal 30 among the plurality of terminal fittings 76 forms a mounting portion 80 that is mounted on the board surface 22 of the printed circuit board (FPC 24). Furthermore, the terminal fittings 76a among the plurality of terminal fittings 76 that are not adjacent to the control terminal 30 (the terminal fittings 76a other than the terminal fitting 76b that form the mounting portion 80) are mounted on the source-side bus bar 14, which is the other of the pair of bus bars.

[0046] Furthermore, each control terminal 30 in each interrupter 32 is superimposed on the FPC 24 on each source-side connecting portion 56 and is electrically connected, for example, via solder (not shown), to the conductor pattern 21 exposed on the board surface 22 of the FPC 24. Terminal fittings 76b, which are mounted on the board surface 22 of the FPC 24 like each control terminal 30 and form the mounting portion 80, are not connected to the conductor pattern 21 of the FPC 24 and serve as so-called dummy terminals. Therefore, in the first embodiment, the control terminals 30 mounted on the conductor pattern 21 and the terminal fittings 76b forming the mounting portion 80 are mounted on the board surface 22 of the FPC 24 around the through-holes 66 in the FPC 24. Other terminal fittings 76a are mounted on the source-side surface 18 exposed through the through-holes 66.

[0047] <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.

[0048] The upper case 36 has a generally flat plate shape or a downwardly opening box shape with a generally rectangular upper bottom wall 82. The lower case 38 has a generally rectangular cylindrical shape with an annular peripheral wall 84. Bus bar support portions 86 are provided on both front-to-rear direction sides of the inner peripheral surface of the peripheral wall 84. 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 86, 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.

[0049] Furthermore, board support portions 88 are provided on both left and right sides of the inner peripheral surface of the peripheral wall 84. These board support portions 88 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 connected to the ends of each FPC 24 folded upward by each fold portion 68 is placed and supported on each board support portion 88 at four locations on the outer peripheral edge. As a result, the control board 20 is positioned above and spaced apart from each blocking portion 32 located below without coming into contact with them.

[0050] The upper opening 90 of the lower case 38 is then covered by the upper case 36, and the lower case 38 and the upper case 36 are fixed together by an appropriate method. As described above, the bottom plate 62, to which the drain and source bus bars 12, 14, the FPCs 24, the circuit breakers 32, etc. are attached, is placed over the lower opening 92 of the lower case 38 and fixed with screws 64. In this manner, the case 34 is formed.

[0051] <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.

[0052] First, the drain-side and source-side bus bars 12, 14 are fixed onto the bottom plate 62 via the adhesive sheet 60. Then, the FPCs 24, each having a through hole 66, are placed on the source-side connection portions 56 of the source-side bus bar 14 and fixed thereto, for example, with an adhesive. Then, the interrupters 32 are arranged so as to straddle the drain-side connection portions 50 of the drain-side bus bar 12 and the source-side connection portions 56 of the source-side bus bar 14 (i.e., the FPCs 24 thereon). This allows the drain terminals 26 of the interrupters 32 to be placed on the drain-side connection portions 50.

[0053] Furthermore, among the terminal fittings 76 constituting each source terminal 28 in each interrupter 32, each terminal fitting 76a that is not adjacent to the control terminal 30 (that is, that does not constitute the mounting portion 80) is placed on the source-side surface 18 of each source-side connection portion 56 through the through-hole 66 in each FPC 24. Furthermore, the control terminal 30 in each interrupter 32 and the terminal fitting 76b adjacent to the control terminal 30 are placed on the board surface 22 of each FPC 24. In particular, the control terminal 30 is placed on the conductor pattern 21 exposed on the board surface 22 of each FPC 24.

[0054] Then, the overlapping portions, i.e., the drain terminals 26 and the drain-side connecting portions 50, the terminal fittings 76a constituting the source terminals 28 and the source-side connecting portions 56, and the control terminals 30 and the conductor patterns 21, are soldered together to establish electrical continuity for mounting. Note that the soldering method may be a conventionally known method such as reflow soldering.

[0055] Thereafter, the bottom plate 62, to which the drain-side and source-side bus bars 12, 14, the FPCs 24, and the circuit breakers 32 are attached as described above, is fixed with screws 64 so as to cover the lower opening 92 of the lower case 38. Next, the drain-side and source-side end bus bars 40, 42 are inserted through the upper opening 90 of the lower case 38 and placed on the bus bar supports 86. In addition, the lower ends of the drain-side and source-side end bus bars 40, 42 are fixed to the connecting portions 48, 54 of the drain-side and source-side bus bars 12, 14, respectively.

[0056] Next, each FPC 24 is folded upward at each fold portion 68, and a control board 20, on which a connector 70 has already been mounted, is fixed to the end of each folded FPC 24, electrically connecting the conductor patterns 21 on each FPC 24 with the control circuit on the control board 20. Then, this control board 20 is placed on each board support portion 88 of the lower case 38. Finally, the upper opening 90 of the lower case 38 is covered with the upper case 36, and the upper case 36 and lower case 38 are fixed together in an appropriate manner, thereby completing the electrical junction box 10.

[0057] When the connector 70 of the electrical junction box 10 assembled as described above 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 of the disconnecting units 32 via the control circuit on the control board 20 and the conductor patterns 21 on each of the FPCs 24. When a disconnection voltage based on the disconnection signal is applied to the control terminal 30, the current path is interrupted in each of the disconnecting units 32, and the electrical connection between the drain-side bus bar 12 and the source-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 of the disconnecting units 32 in response to a disconnection command input from the outside via the connector 70.

[0058] According to the electrical junction box 10 of the first embodiment, one terminal fitting 76b of the multiple terminal fittings 76 constituting the source terminal 28 constitutes a mounting portion 80 that is mounted on the surface 22 of the printed circuit board (FPC 24). This configuration suppresses tilting of the interrupting portion 32 when the interrupting portion 32 is mounted on the drain-side busbar 12, source-side busbar 14, and conductor pattern 21, which is caused by differences in the height positions of the surfaces of the conductor pattern 21, drain-side busbar 12, and source-side busbar 14, compared to when only the control terminal 28 is mounted on the FPC provided on the source-side busbar. This configuration prevents or suppresses tilting of the remaining terminal fittings 76a that are not mounted on the surface 22 of the FPC 24 toward the source-side busbar 14 (raising the control terminal 30). This configuration also prevents or suppresses poor connection problems associated with tilting of the interrupting portions 32.

[0059] The source terminal 28 is configured to include a plurality of terminal fittings 76, one of which, terminal fitting 76b, forms a mounting portion 80 mounted on the board surface 22, and the remaining terminal fittings 76a are mounted on the source-side bus bar 14. In the case of high-voltage power semiconductors, a structure in which a power terminal is configured with a plurality of terminal fittings has conventionally been adopted, but by adopting a structure in which at least one of such a plurality of terminal fittings 76 is mounted on the board surface 22 of the FPC 24 as the mounting portion 80, the effect of suppressing tilt of each circuit breaker 32 as described above can be achieved. In other words, the above effect can be achieved without changing the structure of each circuit breaker 32, for example, by using power semiconductors that are available on the market, and by changing the shape of the FPC 24, which can be more easily changed in shape.

[0060] In the first embodiment, the terminal fittings 76b constituting the mounting portion 80 are not connected to the conductor pattern 21 and serve as so-called dummy terminals. In particular, in the first embodiment, through holes 66 are formed in the FPC 24 at positions corresponding to the terminal fittings 76a that do not constitute the mounting portion 80, and the terminal fittings 76a are electrically connected to the source-side bus bar 14 through the through holes 66. That is, by changing the positions of the through holes 66, it is possible to easily select which of the terminal fittings 76 will serve as the terminal fittings 76a electrically connected to the source-side bus bar 14, or which will serve as the terminal fittings 76b constituting the mounting portion 80. The positions of the through holes 66 can be appropriately set in accordance with the conductor pattern 21 on the FPC 24, and the terminal fittings 76b constituting the mounting portion 80 can be easily selected from the plurality of terminal fittings 76.

[0061] The control terminals 30 and terminal fittings 76b constituting the mounting portion 80 are mounted on the substrate surface 22 of the FPC 24 around the through holes 66 as described above, and other terminal fittings 76a are mounted on the source-side surface 18 exposed through the through holes 66. As a result, the control terminals 30 and mounting portions 80 mounted around the through holes 66 suppress the inclination of each interrupter portion 32, and therefore it is possible to effectively suppress the inclination of each interrupter portion 32 such that the terminal fittings 76a that do not constitute the mounting portion 80 fall toward the source-side bus bar 14 through the through holes 66.

[0062] Second Embodiment Next, an electrical junction box 100 as a circuit body according to a second embodiment of the present disclosure will be described with reference to Fig. 7. Fig. 7 shows the main components of the electrical junction box 100 according to the second embodiment, with the case 34 and other components omitted from the illustration. The basic structure of the electrical junction box 100 according to the second embodiment is the same as that according to the first embodiment, except that, among the multiple terminal fittings 76 constituting the source terminal 28, the terminal fitting 76c constituting the mounting portion 80 is positioned differently in the second embodiment. In the following description, components or parts that are substantially the same as those in the first embodiment will be designated by the same reference numerals in the drawings, and detailed description thereof will be omitted.

[0063] In the first embodiment, the terminal fittings 76b adjacent to the control terminal 30 constitute the mounting portion 80, but in the second embodiment, the terminal fittings 76c, among the multiple terminal fittings 76 arranged in parallel alongside the control terminal 30, that are farthest from the control terminal 30 in the parallel direction (front-rear direction) constitute the mounting portion 80. That is, in the second embodiment, five terminal fittings 76d, among the multiple terminal fittings 76, that are located between the control terminal 30 and the terminal fittings 76c constituting the mounting portion 80 are mounted on the source-side bus bar 14 through the through-holes 66. In particular, in the second embodiment, the terminal fittings 76c constituting the mounting portion 80 are connected to the conductor pattern 21 exposed on the FPC 24.

[0064] In the electrical junction box 100 of the second embodiment, the mounting portion 80 is formed by one terminal fitting 76c of the terminal fittings 76 that constitute the source terminal 28, and therefore the same effects as in the first embodiment can be achieved. In particular, in the second embodiment, the mounting portion 80 is formed by the terminal fitting 76c that is farthest from the control terminal 30. Therefore, each circuit breaker 32 is supported at three points spaced a predetermined distance from each other in the front-rear and left-right directions, further reducing the risk of each circuit breaker 32 being mounted at an angle. Furthermore, because each circuit breaker 32 is supported by the control terminal 30 and the terminal fitting 76c on both sides of the through hole 66 in the front-rear direction, each terminal fitting 76d located therebetween can be more reliably prevented from tilting and falling toward the source-side bus bar 14 through the through hole 66.

[0065] Furthermore, in the second embodiment, the terminal fittings 76c constituting the mounting portion 80 are connected to the conductor pattern 21 of the FPC 24. This makes it possible to transmit, for example, potential information and the like obtained in each of the interrupting portions 32 to the outside via the conductor pattern 21, the control circuit in the control board 20, and the connector 70. As a result, further control is possible using the potential information and the like obtained in each of the interrupting portions 32.

[0066] Third Embodiment Next, an electrical junction box 110 as a circuit body according to a third embodiment of the present disclosure will be described with reference to Figures 8 and 9. Figures 8 and 9 show the main components of the electrical junction box 110 according to the third embodiment, and the case 34 and other components are not shown. In the third embodiment, each FPC 112 as a printed circuit board has a wide portion 114 having an increased width dimension (left-right dimension) at a portion that overlaps with each source side connection portion 56 of the source side bus bar 14. As a result, the wide portion 114 of each FPC 112 overlaps not only each source side connection portion 56 but also each drain side connection portion 50 of the drain side bus bar 12 that opposes each source side connection portion 56 in the left-right direction.

[0067] 9 , in the third embodiment, a portion of the flat terminal fitting 75 constituting the drain terminal 26, which is one of the power terminals, is placed on the substrate surface 116 of the wide portion 114 of the FPC 112 to form a mounting portion 118 (see FIG. 6 for the shape of the flat terminal fitting 75). Another portion of the flat terminal fitting 75 is located outward in the left-right direction from the wide portion 114 of the FPC 112 and is mounted on the drain-side bus bar 12, which is one of a pair of bus bars. In the third embodiment, the arrangement of the terminal fittings 76 on the source terminal 28 side may be the same as, for example, the first embodiment. That is, the terminal fitting 76b adjacent to the control terminal 30 may form a mounting portion 80, which is placed on the substrate surface 116 of the FPC 112, and the remaining terminal fittings 76a may be mounted on the source-side bus bar 14 through the through-holes 66 in the FPC 112. In the third embodiment, for example, two mounting portions 80 and 118 are provided in each interrupter portion 32 .

[0068] In the electrical junction box 110 of the third embodiment, the control terminal 30 and one terminal fitting 76b (mounting portion 80) are mounted on the board surface 116 of the FPC 112, and a portion of the flat terminal fitting 75 constituting the drain terminal 26 forms a mounting portion 118 and is mounted on the board surface 116 of the wide portion 114 of the FPC 112. The remaining portion of the flat terminal fitting 75 is mounted on the drain-side surface 16. In other words, in the third embodiment, the main body 74 and drain terminal 26 of each interrupter 32 are supported over substantially the entire surface. Additionally, the control terminal 30 and one terminal fitting 76b (mounting portion 80) are also supported, reducing the risk of each interrupter 32 being tilted. Note that, when the mounting portion 118 is provided on the drain terminal 26 side, a relatively wide area of ​​each interrupter 32 is supported, so the mounting portion 80 on the source terminal 28 side is not essential.

[0069] Fourth Embodiment Next, an electrical junction box 120 as a circuit body according to a fourth embodiment of the present disclosure will be described with reference to Fig. 10. Fig. 10 shows the main components of the electrical junction box 120 according to the fourth embodiment, with the case 34 and the like omitted from the illustration. The basic structure of the fourth embodiment is similar to that of the third embodiment, for example, and each FPC 112 as a printed circuit board has a wide portion 114 in which the widthwise dimension (left-right dimension) of the portion overlapping with each source-side connection portion 56 is increased.

[0070] In the fourth embodiment, each wide portion 114 is formed to be small enough not to reach each drain terminal 26. Unlike the third embodiment, the drain terminal 26 is not placed on the board surface 116 of the wide portion 114, but rather a portion of the housing constituting the main body 74 is placed on the board surface 116. Therefore, in the fourth embodiment, the housing portion of the main body 74 of each breaker 32 forms a mounting portion 122 that is placed on the board surface 116 of each FPC 112. The electrical junction box 120 of the fourth embodiment having such a structure also achieves the same effects as the third embodiment, and the risk of each breaker 32 being disposed at an angle can be reduced.

[0071] <Modifications> Although Embodiments 1 to 4 have been described above in detail as specific examples of the present disclosure, the present disclosure is not limited to these specific descriptions. 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 embodiments are also included in the technical scope of the present disclosure.

[0072] (1) The pair of power terminals in the circuit breaker are not limited in number or shape, and may be one or more terminal fittings, and may be flat, linear, or bent at the midpoint in the length direction. Similarly, the shape of the control terminal is not limited, and may extend linearly from the main body of the circuit breaker, for example.

[0073] (2) In the above embodiment, the drain terminal 26, the source terminal 28, and the control terminal 30 each protrude in either the left or right direction from the main body 74 of each interrupter 32, but this is not limited to this. That is, at least one of the pair of power terminals (drain terminal, source terminal) and the control terminal may protrude in the front-rear direction from the main body of each interrupter instead of or in addition to the left-right direction.

[0074] (3) In the above embodiment, the control terminal 30 is provided outside (outside in the front-rear direction) the plurality of terminal fittings 76 that make up the source terminal 28 in the parallel direction (front-rear direction) of the plurality of terminal fittings 76. However, this is not limited to this. For example, the plurality of terminal fittings that make up the source terminal may be disposed on both sides of the control terminal.

[0075] (4) In the above embodiment, the mounting portion 80 is formed by one of the terminal fittings 76 b, 76 c among the plurality of terminal fittings 76 that constitute the source terminal 28. However, this is not limited to this. When the source terminal is formed by a plurality of terminal fittings and the mounting portion is formed by these terminal fittings, the mounting portion may be formed by two or more of the plurality of terminal fittings, and it is sufficient that the mounting portion is formed by at least one terminal fitting. Note that when the mounting portion is formed by two or more of the plurality of terminal fittings, some of the plurality of terminal fittings that constitute the mounting portion may be connected to the conductor pattern, or all of the plurality of terminal fittings that constitute the mounting portion may be connected to the conductor pattern, or none of the plurality of terminal fittings that constitute the mounting portion may be connected to the conductor pattern.

[0076] (5) In the above embodiment, among the multiple terminal fittings 76 constituting the source terminal 28, the terminal fittings 76a, 76d other than the terminal fittings 76b, 76c constituting the mounting portion 80 are mounted on the source-side bus bar 14 through one through-hole 66. However, the number and shape of the through-holes are not limited to these. For example, multiple through-holes may be formed corresponding to the multiple terminal fittings, or a circular (including elliptical, oval, etc.) through-hole may be formed.

[0077] (6) In the above embodiment, the control board 20 was provided inside the electrical connection box 10, 100, 110, 120, but it may also be provided outside the electrical connection box, as long as the conductor pattern provided on the printed circuit board and the control circuit provided on the control board are electrically connected.

[0078] (7) In the above embodiment, the printed circuit board is an FPC (flexible printed circuit board) 24, but it may be, for example, a rigid board, and the conductor pattern provided on the rigid board may be electrically connected to a control circuit on a control board provided inside or outside the electrical connection box.

[0079] (8) In the third embodiment, the FPC 112 is provided with a wide portion 114 that extends to the drain terminal 26. Alternatively, or in addition, the drain terminal may be extended onto the printed circuit board.

[0080] (9) In the above embodiment, multiple blocking units 32 are provided, but only one blocking unit may be provided. Even when multiple blocking units are provided, it is sufficient that one of them has the structure according to the present disclosure.

[0081] (10) The shape of the case 34 described in the above embodiment is merely an example, and the shape of the case is not limited in any way.

[0082] (11) In the above embodiment, the electrical connection boxes 10, 100, 110, 120 as circuit bodies were provided between the power source and the load, but this is not limited to this form, and the pair of bus bars may be provided between two conductive paths to form a current path.

[0083] REFERENCE SIGNS LIST 10 Electrical junction box (circuit body, embodiment 1) 12 Drain side bus bar (one of a pair of bus bars) 14 Source side bus bar (the other of the pair of bus bars) 16 Drain side surface 18 Source side surface 20 Control board 21 Conductive pattern 22 Board surface 24 FPC (printed circuit board) 26 Drain terminal (one of a pair of power terminals) 28 Source terminal (the other of the pair of power terminals) 30 Control terminal 32 Breaker 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 part 46 Source side external connection part 47 Through hole 48 Connecting part 50 Drain side connection part 52 Front opening 54 Connecting part 56 Source side connection part 58 Rear opening 60 Adhesive sheet 62 Bottom plate 64 Screw 66 Through hole 68 Folded portion 70 Connector 72 Opening 74 Main body 75 Flat terminal fitting 76 Terminal fitting 76a, 76b Terminal fitting (Embodiments 1 and 3) 76c, 76d Terminal fitting (Embodiment 2) 78 Vertical portion 80 Placement portion 82 Upper bottom wall 84 Peripheral wall 86 Bus bar support portion 88 Board support portion 90 Upper opening 92 Lower opening 100 Electrical junction box (circuit body, Embodiment 2) 110 Electrical junction box (circuit body, Embodiment 3) 112 FPC (printed circuit board) 114 Wide portion 116 Board surface 118 Placement portion 120 Electrical junction box (circuit body, Embodiment 4) 122 Placement portion

Claims

1. A circuit body comprising: a pair of bus bars forming a current path between two conductive paths; a printed circuit board placed on at least one of the surfaces of the pair of bus bars, and having a conductor pattern connected to a control circuit exposed on its surface; and a circuit breaker that includes a pair of power terminals mounted on the surfaces of the pair of bus bars, respectively, and a control terminal mounted on the conductor pattern, and that passes and cuts off current between the pair of bus bars, wherein at least one of the pair of power terminals has a mounting portion that is mounted on the surface of the printed circuit board.

2. The circuit body described in claim 1, wherein one of the pair of power terminals is connected to one of the pair of bus bars connected to one of the two conductive paths, and the other of the pair of power terminals is connected to the other of the pair of bus bars connected to the other of the two conductive paths, the other of the power terminals is configured to include a plurality of terminal fittings, at least one of the terminal fittings forms the mounting portion placed on the surface of the substrate, and the remaining terminal fittings are mounted on the other of the pair of bus bars.

3. The circuit body according to claim 2, wherein at least one of the terminal fittings constituting the mounting portion is connected to the conductor pattern.

4. The circuit body according to claim 2 or 3, wherein at least one of the terminal fittings constituting the mounting portion is not connected to the conductor pattern.

5. A circuit body as described in any one of claims 2 to 4, wherein a plurality of the terminal fittings are arranged in parallel alongside the control terminal, and the mounting portion is configured to include the terminal fitting that is furthest from the control terminal in the parallel direction.

6. A circuit body as claimed in any one of claims 2 to 5, wherein the printed circuit board is placed on the surface of the other of the pair of bus bars, the surface of the other of the pair of bus bars is partially exposed through a through hole provided in the printed circuit board, the control terminal mounted on the conductor pattern and at least one of the terminal fittings constituting the mounting portion are placed around the through hole in the printed circuit board, and other terminal fittings are mounted on the surface exposed through the through hole.

7. A circuit body as claimed in any one of claims 1 to 6, wherein one of the pair of power terminals is connected to one of the pair of bus bars connected to one of the two conductive paths, and the other of the pair of power terminals is connected to the other of the pair of bus bars connected to the other of the two conductive paths, one of the power terminals includes a flat terminal fitting, a part of the flat terminal fitting constitutes the mounting portion placed on the surface of the substrate, and another part of the flat terminal fitting is mounted on one of the pair of bus bars.

8. A circuit body comprising: a pair of bus bars forming a current path between two conductive paths; a printed circuit board placed on at least one of the surfaces of the pair of bus bars, and having a conductor pattern connected to a control circuit exposed on the surface of the board; and a circuit breaker unit that includes a pair of power terminals mounted on the surfaces of the pair of bus bars, respectively, and a control terminal mounted on the conductor pattern, and that passes and cuts off current between the pair of bus bars, wherein a housing portion of a main body of the circuit breaker unit forms a mounting portion that is placed on the board surface of the printed circuit board.