JP2006187122A - Circuit structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric connection box in which densification can be realized by laying a second bus bar coated with an insulating film on a first bus bar or a control circuit board structure, thereby increasing the degree of freedom in design of conduction path and wiring a large number of conduction paths in a limited space. <P>SOLUTION: A branch portion 12 and a power supply distributing portion 13 are combined entirely into substantially L-shape while butting the edges each other to produce a circuit body 11 which is then surrounded by a casing 15 thus obtaining an electric connection box 10. A second bus bar 35 is wired in the power supply distributing portion 13. An insulating film is formed on the surface of the second bus bar by so-called power painting where insulating powder of mica or silicon (Si) is sprayed to the surface of the second bus bar. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a circuit structure that supplies power.

  For example, Patent Document 1 discloses a conventional circuit structure. This is mounted on an automobile, for example, and is used as a power distributor that controls the power supply to each electronic device via a power source such as an in-vehicle battery and each electronic device. It is.

This type of circuit structure includes a plurality of bus bars arranged in a plane, a control circuit board stacked on these bus bars via an insulating layer, and a semiconductor switching device mounted on the control circuit board. The power supply to each electronic device is controlled by energizing each bus bar by operating the semiconductor switching device.
JP 2003-164039 A

By the way, comfort and safety required for automobiles are increasing, and the number of electronic devices installed in automobiles to meet these requirements is increasing, and they are mounted on control circuit boards. The number of switching devices to be increased. Along with this, a large number of conductive paths for supplying power required in the circuit structure are required. On the other hand, since the space for mounting the circuit structure in an automobile is limited, it is necessary to arrange as many switching devices and conductive paths as possible in the same volume (capacitance) circuit structure, that is, the height of the circuit structure. Densification is desired.
The present invention has been completed based on the above circumstances, and an object thereof is to provide an electrical junction box capable of increasing the density.

  As means for achieving the above object, the invention of claim 1 is directed to the control circuit board, the switching device mounted on the control circuit board, and the control circuit board via an insulating layer. A plurality of first bus bars that are stacked, and each of the plurality of first bus bars is energized by operating the switching device, wherein the first bus bar or A feature is that a second bus bar covered with an insulating film is laminated on the control circuit board.

  According to a second aspect of the present invention, in the first aspect of the present invention, the second bus bar is made of a plate-like metal piece having a surface wider than the thickness, and the wide surface is the surface of the second circuit component. It is characterized in that it is arranged so as to be perpendicular to.

  The invention of claim 3 is characterized in that in the structure of claim 1 or claim 2, a plurality of the second bus bars are stacked.

  According to a fourth aspect of the present invention, there is provided the apparatus according to any one of the first to third aspects, wherein the tip end portion of the second bus bar is configured as an external terminal for connection to the outside.

  According to a fifth aspect of the present invention, in the device according to the fourth aspect, the external terminal is formed in a male tab shape at a tip end portion of the second bus bar that is not covered with the insulating film. Is characterized in that it is supported by being penetrated into the housing of the connector fitted to the mating terminal.

<Invention of Claim 1>
Since the second bus bar covered with the insulating film is laminated on the first bus bar or the control circuit board, the degree of freedom in designing the conductive path is increased, and a large number of conductive paths can be routed in a limited space. Therefore, it is possible to increase the density.

<Invention of Claim 2>
Since the second bus bar is arranged perpendicular to the first bus bar or the control circuit board, a large number of second bus bars can be arranged on the circuit structure by effectively using the space on the circuit structure. Further higher density is possible.

<Invention of Claim 3>
Since a plurality of second bus bars are stacked, it is possible to achieve higher density.

<Invention of Claim 4>
Since the second bus bar directly connects to an external device or the like, it is not necessary to add a connection structure with other devices, and the circuit structure can be downsized.

<Invention of Claim 5>
Since the external terminal is formed integrally with the second bus bar by directly extending the distal end portion of the second bus bar, it is possible to make a simple structure and when connecting to the other party via other members In comparison, the contact resistance can be reduced.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. The electrical junction box 10 of the present embodiment is used as a power distributor that controls the power supply to each electronic device via a power source such as an in-vehicle battery and a load such as each electronic device, for example. is there.
As shown in FIG. 1, the electrical junction box 10 is formed in a substantially L-shape as a whole by abutting the edges of the branch path portion 12 and the power distribution portion 13 formed in a substantially flat plate shape. The circuit body 11 is surrounded by a casing 15, and an exterior product mounting portion 14 is formed on the upper surface of the electrical connection box 10.

The casing 15 has a configuration in which the side case 17 and the upper case 18 are assembled to the main case 16 (see FIG. 1).
As shown in FIG. 1, the main case 16 is formed with an upper housing portion 16H that opens upward and a side housing portion 16V that opens to one side (the left rear side in FIG. 1). The upper housing portion 16 </ b> H closes the opening of the upper case 18 by assembling the upper case 18 after housing the branch path portion 12. Further, the upper housing portion 16H (not shown) is formed with a connector housing for connecting to an external device on the outer bottom surface.
On the other hand, the side accommodating portion 16V is configured to close the opening portion by assembling the side case 17 to which the power distribution portion 13 is assembled. Further, an insertion hole 16A for exposing the control connector 37 formed in the power distribution portion 13 to the outside is formed in the wall surface on the side facing the opening of the side accommodating portion 16V.
Further, an exterior product insertion hole 18A is formed in the upper surface of the upper case 18, and a bifurcated terminal extending from the branch path 12 or the power distribution unit 13 is inserted into the exterior product insertion hole 18A. As a result, the exterior product mounting portion 14 is configured. When an exterior product (in this embodiment, a fuse H or a fusible link F) is assembled in the exterior product insertion hole 18A of the exterior product mounting portion 14, the terminal of the exterior product is sandwiched between the bifurcated terminals so that conductive connection is established. It has come to be illustrated.

As shown in FIG. 3, the branch path portion 12 is formed by vertically stacking a bus bar circuit 22 including a plurality of bus bars 21 formed by punching a metal flat plate into a predetermined circuit shape via an insulating plate 25. is there.
The end portion of the bus bar 21 is formed with a connection portion 23 that is connected to other circuits, electronic components, etc., but extends horizontally with the vertical connection portion 23V that is bent vertically according to the circuit configuration of the bus bar circuit 22. The horizontal connection portion 23H is selectively formed.
The insulating plate 25 insulates the upper and lower bus bar circuits 22, and a through hole 26 is formed at a predetermined location, and the vertical connection portion 23 </ b> V projects from the front surface or the back surface of the branch path portion 12 through the through hole 26. It is like that. In FIG. 3, four insulating plates 25 are vertically arranged, but the through holes 26 are omitted except for the insulating plate 25 described on the uppermost side.
In the present embodiment, the tip of the vertical connection portion 23V protruding to the upper surface side of the branch path portion 12 is formed in a bifurcated shape so that the terminal of the fuse H or the fusible link F can be sandwiched. Further, the tip of the vertical connection portion 23 </ b> V protruding to the lower surface side of the branch path portion 12 has a tab shape and extends into a connector housing (not shown) formed in the upper housing portion 16 </ b> H of the main case 16. The male terminal is configured.
The horizontal connection portion 23H is arranged so as to be parallel to one place (the left rear side in FIG. 3) of the butt portion between the branch path portion 12 and the power distribution portion 13, and the horizontal connection portion 23H is disposed in the power distribution portion 13. To connect with.

As shown in FIGS. 4 and 6, the power distribution unit 13 includes a bus bar circuit 32 formed by punching a metal flat plate into a predetermined circuit shape including a plurality of first bus bars 31 and a circuit in which a predetermined printed circuit is formed. A switching device 34 such as a relay or a semiconductor switch and electronic components for controlling these (not shown) are mounted on the upper surface side of the circuit board 33 to which the board 33 is bonded. In addition, a control connector 37 for connecting the circuit board 33 and an external device is mainly disposed at a corner of the power distribution unit 13 (see FIG. 7). The control connector 37 has a tab-shaped male terminal disposed in a substantially rectangular tube-shaped housing, and the male terminal is soldered to a through hole 33H formed in the circuit board 33 so as to be connected to the circuit board 33. Conductive connection is made.
In addition, a metal flat plate-like heat radiating plate 19 is bonded to the bus bar circuit 32 side of the power distribution unit 13 with an adhesive (for example, an epoxy adhesive). The heat radiating plate 19 constitutes a wall surface (entire surface) of the outside of the side case 17 (front left side in FIG. 3), and the heat radiating plate 19 itself is exposed to the outside. With this configuration, the power distribution unit 13 transfers heat generated from the switching device 34 of the power distribution unit 13 to the heat radiating plate 19 via the bus bar circuit 32 and radiates heat from the heat radiating plate 19 to the outside. ing.

Now, the second bus bar 35 is routed on the surface of the power distribution unit 13 (see FIG. 6).
The second bus bar 35 is a strip-shaped conductive path having a surface wider than a thickness of a metal flat plate, and is disposed on the surface (mounting surface) on the side where the switching device 34 is mounted in the power distribution unit 13. ing. The second bus bar 35 is formed by appropriately rotating from a predetermined connection location on the circuit board 33 side such as each switching device 34 in the power distribution unit 13 toward the right back in FIG. 6. The second bus bar 35 is fixed on the circuit board 33 by an adhesive (for example, a silicone-based adhesive) or an adhesive sheet (for example, an adhesive applied to both surfaces of an insulating sheet to provide adhesiveness).
As shown in FIGS. 4 and 6, the tip portion of the second bus bar 35 connected to the circuit board 33 side is bent so that a step is formed toward the circuit board 33 side rather than a portion that circulates on the mounting surface. A step connection portion 35D is formed. The step connection portion 35D can be connected to the bus bar circuit 32 (by soldering or the like) through an accommodation hole 33A formed through the circuit board 33.

On the other hand, the end of the second bus bar opposite to the step connection portion 35D (arranged at the right rear side in FIG. 6) has a vertical external terminal 35V bent vertically upward with respect to the circuit surface of the power distribution portion 13. Formed. The vertical external terminal 35V protrudes into a cavity 36C in a housing 36 that is integrally formed with the side case 17, and serves as a male terminal for connection to the other side.
Further, the housing 36 is provided with a connection terminal 31V in which the end portion of the first bus bar is bent and raised vertically upward with respect to the circuit surface of the power distribution unit 13 in parallel with the vertical external terminal 35V. Both the connection terminal 31V of the first bus bar and the vertical external terminal 35V of the second bus bar are provided.
Further, the housing 36 accommodates the relay terminal 40 in the cavity 36 </ b> C, and electrically connects the vertical external terminal 35 </ b> V or the connection terminal 31 </ b> V of the power distribution part 13 and the horizontal connection part 23 </ b> H of the branch path part 12. .

Further, the second bus bar 35 has a partition portion 35 </ b> C formed so that a wide surface thereof is perpendicular to the surface of the power distribution unit 13 at a part of the portion that circulates on the circuit board 33. Is also provided.
Here, a space having a certain height for disposing the switching device 34 exists on the power distribution unit 13, but the second bus bar 35 having the partition portion 35 </ b> C as in the present embodiment is used. Thus, the second bus bar 35 can be arranged using the space efficiently.

Incidentally, the surface of the second bus bar according to the present embodiment is covered with an insulating film as shown in FIG. This insulating film is formed by so-called powder coating in which an insulating powder such as mica (mica) or silicon (Si) is sprayed on the surface of the second bus bar, thereby insulating the second bus bar. The portion covered with the film is not short-circuited even if it comes into contact with another conductive member. However, portions that are conductively connected to the circuit board 33 or the switching device 34, such as the tip portion of the second bus bar 35, are not covered with an insulating film so as not to hinder soldering or the like. (See FIG. 5).
Furthermore, since the powder used in the present embodiment has good thermal conductivity, heat generated when a current flows through the second bus bar or heat directly transmitted from the connected switching device 34 or the like can be dissipated into the air. Yes. In addition, heat from an electronic element such as the switching device 34 that is close to the second bus bar 35 (not directly electrically connected) can be absorbed and dissipated in the air.

In the present embodiment, although not shown in detail, when the step connection portion 35D is directly connected to the terminal of the switching device 34 in the power distribution portion 13, a circuit board is provided at a location corresponding to the step connection portion 35D. An accommodation hole 33A penetrating over both 33 and the bus bar circuit 32 is formed, and the step connection portion 35D is accommodated in the accommodation hole 33A. At the same time, the upper surface of the step connection portion 35D is formed to be substantially the same height as the upper surface of the first bus bar. Thereby, one of the terminals of the switching device 34 can be soldered to the connection portion of the conductive path of the circuit board 33, and the other can be soldered to the step connection portion 35 </ b> D of the second bus bar 35. Here, the tip portion of the terminal of the switching device 34 to be soldered to the step connection portion 35D extends downward (to the bus bar circuit 32 side) from the tip portion to be soldered to the conductive path of the circuit board 33. As a result, soldering can be reliably performed even if there is a step in the connecting portion.
In the present embodiment, a mounting hole 33B for the switching device 34 is formed adjacent to the accommodation hole 33A on the circuit board 33 side. The mounting hole 33B is for connecting an electrode (gate electrode) formed on the bottom surface of the main body of the switching device 34 directly to the bus bar circuit 32, and is formed in the circuit board 33 so as to communicate with the accommodation hole 33A. There are some (see FIGS. 4 and 6).

As described above, according to the present embodiment, since the second bus bar 35 covered with the insulating film is configured to be routed on the power distribution unit 13, it is possible to compensate for the insufficient conductive path in the bus bar circuit 32. Since the degree of freedom in the design of the supply path is increased and a large number of conductive paths can be arranged in a limited space, the density can be increased.
Furthermore, in the present embodiment, by using the second bus bar 35 having the partition portion 35C, it is possible to efficiently arrange the second bus bar 35 using the space. Conductive paths can be formed, and the density can be further increased, and the degree of freedom in design is further improved.
Moreover, since the partition part 35C of the 2nd bus bar 35 can contact the front and back with air, the 2nd bus bar 35 itself has high heat dissipation.

Moreover, since the housing 36 of this embodiment comprises the male terminal of the housing 36 with the vertical external terminal 35V integrally formed by extending the front-end | tip part of the 2nd bus-bar 35 directly, other members (independent terminal) ), The contact resistance can be reduced, and the connection can be made with such a simple configuration, so that the density of the electrical connection box 10 can be increased and the degree of freedom in circuit design. Will improve.
In this embodiment, the vertical external terminal 35V connected to the second bus bar 35 and the connection terminal 31V connected to the first bus bar 31 can be connected to each other by one member accommodated in the same housing 36. 12 can be easily connected.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, the insulating film is formed on the second bus bar 35 by powder coating, but the insulating film may be formed by other methods such as resin coating or electrostatic powder coating. Good. Moreover, as long as insulation can be ensured, the surface of the second bus bar may be coated with a paint.
(2) In the above-described embodiment, the connection portion forms a male tab terminal of a connection connector with the branch path portion. For example, the connection portion may constitute a terminal for connection with a normal connector, or a fuse. It may constitute a fuse terminal for connection. In this case, the shape of the tip portion is not limited to the tab shape as in the above embodiment, but may be a forked shape or a female terminal.
(3) In the above embodiment, the second bus bar 35 is disposed on the surface (mounting surface) on which the switching device 34 of the power distribution unit 13 is mounted. For example, the power distribution unit 13 may be disposed on the bus bar circuit 32 side.
(4) In the above embodiment, the power distribution unit 13 and the branch path unit 12 are connected via the relay terminal 40 accommodated in the housing 36. It may have a structure in which the terminal and the terminal of the branch path portion 12 can be directly fitted.
(5) In the above-described embodiment, the fuse H and the fusible link F are mounted as exterior products. However, the present invention is not limited thereto, and may be a relay, a sensor, an ECU, or the like.
(6) In the above embodiment, the electrical connection of each circuit of the branch path portion 12 and the power distribution portion 13 is performed by terminal fitting via the relay terminal 40. For example, tab-shaped terminals are connected to each other. It may be connected by welding (resistance welding, laser welding, etc.).

Disassembled perspective view of electrical junction box Perspective view of electrical junction box An exploded perspective view of the electrical junction box in a state in which the components of the branch path are disassembled Disassembled perspective view of power distribution unit Perspective view of the second bus bar Perspective view of power distribution unit A perspective view of the power distribution unit with the side cover assembled

Explanation of symbols

10 ... Electric junction box 12 ... Branch part (branch circuit body)
13: Power distribution unit (circuit structure)
31 ... 1st bus bar 31V ... Connection terminal 33 ... Control circuit board 34 ... Switching device 35 ... 2nd bus bar 35V ... Vertical external terminal (external terminal)
36. Housing (connector housing)

Claims (5)

The switching circuit board includes a control circuit board, a switching device mounted on the control circuit board, and a plurality of first bus bars each stacked on the control circuit board via an insulating layer. A circuit structure configured to energize each of the plurality of first bus bars by operating a device,
2. A circuit structure, wherein a second bus bar covered with an insulating film is laminated on the first bus bar or the control circuit board. The second bus bar is made of a flat strip-shaped metal piece having a surface wider than the thickness, and the wide surface is arranged to be perpendicular to the surface of the second circuit component. The circuit structure according to claim 1. The circuit structure according to claim 1 or 2, wherein a plurality of the second bus bars are stacked. 4. The circuit structure according to claim 1, wherein a tip end portion of the second bus bar is configured as an external terminal for connection with the outside. 5. The external terminal is formed in the shape of a male tab at the tip of the second bus bar that is not covered with the insulating film, and the external terminal is penetrated and supported in the housing of the connector fitted with the mating terminal. The circuit structure according to claim 4, wherein the circuit structure is provided.

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