JP2003164039A - Circuit structure and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: In a circuit structure, a power circuit including a semiconductor switching element is constructed with a simple and thin structure, and heat dissipation of the element is improved. In addition, the circuit component can be manufactured efficiently. SOLUTION: A plurality of bus bars 1 constituting a power circuit
A circuit structure in which 1, 12, and 14 are adhered to the surface of a control circuit board 20 and semiconductor switching elements are mounted thereon.
Further, the circuit structure includes a metal busbar structure plate 10 having a shape in which busbars are connected to each other and a control circuit board 2.
Then, the semiconductor switching element can be mounted and the busbars can be separated from each other after bonding them to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit structure having a bus bar forming a power circuit and a control circuit board for controlling the driving of a semiconductor switching element provided in the power circuit, and a method for manufacturing the same. Is.

[0002]

2. Description of the Related Art Conventionally, as a means for distributing electric power from a common vehicle-mounted power source to each electronic unit, an electric power distribution circuit has been constructed by stacking a plurality of bus bar boards, and a fuse or a relay switch has been incorporated therein. Junction boxes are generally known.

Further, in recent years, in order to realize the miniaturization and high-speed switching control of such an electric connection box, a semiconductor switching element such as an FET, which is interposed between an input terminal and an output terminal, has been developed in place of the relay. Has been done.

For example, in Japanese Unexamined Patent Publication No. 10-35375, a bus bar substrate forming a current circuit and an FE as a semiconductor switching element incorporated in the current circuit are disclosed.
T and a control circuit board for controlling the operation of the FET, and the bus bar board and the control circuit board are arranged in two stages vertically while being separated from each other, and the FET is interposed between them.
Is provided, and the drain terminal and the source terminal of this FET are connected to the bus bar substrate, while the gate terminal of the FET is connected to the control circuit substrate.

[0005]

The electrical junction box disclosed in the above publication requires at least two boards, a busbar board and a control circuit board, and these boards are three-dimensionally arranged with a space between them. However, it is necessary to secure a space for disposing the FET between both substrates. Therefore, although the FET can be made smaller than the conventional relay-type electric junction box, the overall configuration is complicated and the size cannot be sufficiently reduced, and reduction of the height dimension is a major issue.

Further, in the electric connection box, since the FET is arranged between the bus bar substrate and the control circuit substrate, the F
The heat generated by ET tends to be trapped between the two substrates, and it is necessary to take a complicated structure for heat dissipation.

Further, in the electric connection box, the drain terminal and the source terminal of the FET must be connected to the lower bus bar board, while the gate terminal must be connected to the upper control circuit board. Assembly work is complicated and automation is difficult, and improvement is desired.

In view of such circumstances, the present invention provides a circuit structure having a simple and thin structure, which is capable of constructing a power circuit including a semiconductor switching element such as an FET and which is excellent in heat dissipation of the semiconductor switching element. And, moreover,
It is an object of the present invention to provide a method capable of efficiently manufacturing the circuit structure.

[0009]

As a means for solving the above problems, the present invention provides a plurality of bus bars constituting a power circuit, a semiconductor switching element provided in the power circuit, and this semiconductor switching element. A control circuit board for controlling the driving of the bus bar, the bus bar is adhered to the surface of the control circuit board in a state of being aligned on substantially the same plane, and the semiconductor switching element is provided on both the bus bar and the control circuit board. It is implemented.

In this structure, a plurality of bus bars forming the power circuit are adhered to the surface of the control circuit board in a state of being arranged on substantially the same plane, and the semiconductor switching elements are provided on both the bus bar and the control circuit board. Since it is mounted, the height dimension (thickness dimension) of the entire circuit structure is extremely small, and the busbar board required in the conventional electrical junction box (busbar held by an insulating board)
A wiring material for connecting the semiconductor switching element to each substrate is basically unnecessary (however, the present invention does not prevent the wiring material from being partially used). Therefore, as compared with the conventional electrical junction box in which the busbar substrate and the control circuit substrate are arranged apart from each other, and the semiconductor switching elements are connected to both substrates, the overall configuration is greatly reduced in thickness and simplified. It

Specifically, in order to mount the semiconductor switching element on both the bus bar and the control circuit board, for example, a through hole is provided in the control circuit board, and
A part of the terminals of the semiconductor switching element is connected to the surface of the control circuit board opposite to the surface to which the bus bar is bonded, and another terminal of the semiconductor switching element is connected through the through hole. It may be configured to be connected to the bus bar. According to this configuration, the semiconductor switching element can be mounted on both the control circuit board and the bus bar while maintaining the thin structure with a simple configuration in which the through holes are provided at appropriate places on the control circuit board.

In this case, the semiconductor switching element has an energizing terminal on the back surface of its main body, and the control circuit board is provided with a through hole having a size into which the main body of the semiconductor switching element can be inserted. It is more preferable that the main body of the semiconductor switching element is mounted on the bus bar in a state where the current-carrying terminals on the back surface of the main body of the semiconductor switching element are in contact with the bus bar through the holes. According to this configuration, since the semiconductor switching element is mounted so that the energizing terminals provided on the back surface of the main body of the semiconductor switching element directly contact the bus bar, the number of terminals protruding from the main body of the semiconductor switching element is reduced, and the configuration is simpler. In addition, the mounting process of the semiconductor switching element is simplified.

In the present invention, the specific arrangement of each bus bar is not particularly limited, but it is preferable that a plurality of bus bars project laterally from the control circuit board to form a terminal connected to an external circuit. This facilitates the connection between the power circuit formed by the bus bar and the external circuit.

Further, if the bus bars forming the terminals are bent in the same direction and in a direction substantially orthogonal to the control circuit board, the area occupied by the entire circuit structure is equal to the bending. Is decreasing,
The external wiring material can be connected to each terminal from the same direction, and the wiring space can be reduced and the wiring connection work can be facilitated.

Further, if the connector is formed by providing the housing made of an insulating material around the terminal, the terminal can be more easily connected to the external wiring material by using the connector. It will be possible.

The housing may be a single body, but if it is made of an insulating material and has a case for accommodating the bus bar and the control circuit board, at least a part of the housing is formed integrally with the case. By
The number of parts is further reduced.

In this case, a waterproof wall surrounding the region including the semiconductor switching element is provided upright in the case, and the inside of the waterproof wall is sealed with a potting agent while the opening of the waterproof wall is covered with a cover. It is more preferable that the structure is stopped. With this configuration, each semiconductor switching element can be reliably waterproofed with a simple structure.

As the power circuit formed by the bus bar, for example, a power distribution circuit that distributes power from a common power source to a plurality of electric loads is suitable. In that case, the terminals are:
A power distribution including an input terminal connected to a power source and a plurality of output terminals connected to an electric load, wherein the plurality of bus bars output electric power supplied to the input terminal from the output terminal to each of the electric loads. It may be configured as a circuit.

Further, the terminal can include a signal input terminal to which a command signal is inputted from the outside,
In that case, a predetermined command signal is input to the control circuit board with a simple configuration in which the bus bar forming the signal input terminal is electrically connected to the control circuit provided on the control circuit board. be able to.

Further, in the circuit structure according to the present invention,
If a heat dissipation member is provided on the opposite side of the control circuit board with the busbar sandwiched and the busbar is connected to the heat dissipation member via an insulating layer, the heat dissipation performance can be further enhanced. become.

Further, the present invention is a circuit structure including a plurality of bus bars forming a power circuit, a semiconductor switching element provided in the power circuit, and a control circuit board for controlling the driving of the semiconductor switching element. A method of manufacturing a busbar forming step of forming a metal busbar constituting plate having a shape in which the busbars are connected to each other, an adhering step of adhering the busbar constituting plate and the control circuit board, and the adhering step. After the step, a mounting step of mounting the semiconductor switching element on both a predetermined bus bar included in the bus bar constituent plate and the control circuit board, and a disconnecting step of separating the bus bars from each other after the adhering step are included.

According to this manufacturing method, the busbar component plate having a shape in which the busbars are connected to each other and the control circuit board are adhered to each other. Therefore, a plurality of busbars are kept on the control circuit board in a predetermined arrangement. It is possible to bond them to each other at the same time, and then, by separating the bus bars from each other, a regular power circuit can be easily constructed. In addition, since the semiconductor switching element mounting process is performed in a state where the bus bar and the control circuit board are adhered, it is possible to mount the semiconductor switching element on both the bus bar and the control circuit board in a single process. The work efficiency is dramatically simplified as compared with the case where the terminals of the semiconductor switching elements are individually connected to the bus bar substrate and the control circuit substrate which are arranged apart from each other as described above.

The order of the mounting step and the separating step after the adhering step does not matter.

In this method, the busbar forming plate formed in the busbar forming step has a shape in which the busbar forming parts are arranged inside the outer frame and at least a part of these busbar forming parts are connected to the outer frame. In the bonding step, the control circuit board is bonded to a portion inside the outer frame of the bus bar constituent plate, and the separating step cuts between the outer frame and the bus bar constituent portion. Those including the step of performing are more preferable. According to this method, since the bus bar constituting plate includes the outer frame, the bus bar constituting plate has high rigidity, and the work of adhering to the control circuit board is facilitated accordingly. Moreover, after the adhesion, the appropriate power circuit can be easily constructed by separating the outer frame from the bus bar component.

Further, the busbar constituting plate formed in the busbar forming step may have a portion for directly connecting the busbar constituting portions. In that case, by forming the connecting portion so as to be located outside the region where the control circuit board is bonded, the connecting portion can be easily cut after the bonding with the control circuit board.

The bonding step preferably includes, for example, a step of applying an adhesive on the control circuit board by printing, whereby the control circuit board and the bus bar component board can be bonded efficiently. .

In the mounting step, some terminals of the semiconductor switching element are connected to the surface of the control circuit board opposite to the surface to which the bus bar is adhered, and
It is preferable to connect the other terminal of the semiconductor switching element to the bus bar through a through hole provided in the control circuit board. According to this configuration, it becomes possible to mount the semiconductor switching element on both the control circuit board and the bus bar simultaneously from one direction.

In this case, before the mounting step, the thickness of the control circuit board is approximately equal to the thickness of the semiconductor switching element between the terminal connected to the control circuit board and the terminal connected to the bus bar. If the step is provided, the terminals of the semiconductor switching element are not deformed unduly regardless of the thickness of the control circuit board, and the terminals are directly connected to both the control circuit board and the bus bar. Can be implemented. Therefore, the stress of each terminal after mounting is significantly reduced.

Further, in the method according to the present invention, the plurality of bus bars protruding laterally from the control circuit board in the state after the bonding step have the same direction but substantially orthogonal to the control circuit board. It is more preferable to include a bending step of forming a terminal to be connected to an external circuit by bending the terminal. By performing such a bending step, it becomes possible to connect the external wiring member to each terminal from one direction, and the connecting work is simplified.

Further, after the bending step, a connector forming step of forming a connector by providing a housing made of an insulating material around the terminal is performed, so that the connector can be used to more easily connect to an external wiring material. It will be possible to do.

Further, by performing the step of connecting the bus bar adhered to the control circuit board to the heat dissipation member via the insulating layer, it becomes possible to obtain a circuit structure having further excellent heat dissipation.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. It should be noted that here, a method for manufacturing a circuit assembly that constitutes a power distribution circuit that distributes electric power supplied from a common power source mounted on a vehicle or the like to a plurality of electric loads will be described. The application of is not limited to this, and can be widely applied to the case where the on / off switching of energization in the power circuit is performed by the semiconductor switching element.

1) Busbar forming step First, in manufacturing the circuit structure, a busbar forming plate 10 as shown in FIG. 1 is formed.

The illustrated bus bar constituent plate 10 has a rectangular outer frame 16, and a plurality of input terminal bus bars 11 constituting an input terminal and a plurality of outputs constituting an output terminal in an inner region thereof. A large number of bus bars including the terminal bus bar 12 and a plurality of signal input terminal bus bars 14 are arranged in a predetermined pattern, and a suitable bus bar is connected to the outer frame 16 by a narrow connecting portion 18, and is also specified. The busbars are interconnected by the narrow connecting portions 18.

In the illustrated example, the end portion 11a of the input terminal bus bar 11 and the outer end portion 14 of the signal input terminal bus bar 14 are shown.
Although all a are arranged on the left side of the bus bar constituent plate 10 and all the end portions 12a of the output terminal bus bar 12 are arranged on the right side of the bus bar constituent plate 10, the respective bus bar end portions 11a, 12a, 14a are It is a free end that is not connected to the outer frame 16.

The busbar-constituting plate 10 can be easily formed, for example, by punching a single metal plate by pressing.

The outer frame 16 does not necessarily have to be included. However, by including the outer frame 16, the rigidity of the entire busbar component plate 10 is increased, and the work of adhering to the control circuit board 20 is facilitated by that amount, and the busbar body is damaged by gripping the outer frame 16. Can be handled easily without Moreover, after the adhesion, the appropriate power circuit can be easily constructed by separating the outer frame from the bus bar component.

2) Bonding Step The control circuit board 20 is bonded to one surface (the upper surface in FIG. 1) of the bus bar constituent plate 10 to obtain the state of FIG.

This control circuit board 20 is composed of a FET which will be described later.
It includes a control circuit for controlling the switching operation of the (semiconductor switching element) 30, and can be composed of, for example, a normal printed circuit board (an insulating board on which conductors forming the control circuit are printed and wired). . In the illustrated example, a sheet-shaped control circuit board 20 having a very small thickness (for example, 0.3 mm) is used in order to further promote the reduction in thickness and the improvement in waterproofness, and the control circuit board 20 is placed in an appropriate place. A plurality of through holes 22 are provided. The through hole 22 is for mounting the FET 30 on the bus bar, and details thereof will be described later.

The outer shape of the control circuit board 20 is made smaller than the outer shape of the bus bar constituent plate 10, and particularly the lateral width of the board is made sufficiently smaller than the bus bar constituent plate 10. Specifically, by adhering the control circuit board 20 to the central portion of the bus bar component board 10 as shown in the drawing,
An end portion 11a of the input terminal bus bar 11 and an end portion 14a of the signal input terminal bus bar 14 project from the bus bar constituent plate 20 to the left outside, and the output terminal bus bar 12 to the right outside.
End portion 12a of each of the projections is projected, and all the connecting portions 1
8 is exposed outside the control circuit board 20 (FIG. 2).

The control circuit board 20 is used as the bus bar component plate 1.
Various techniques can be used to adhere to zero. An example is shown below.

Conductor patterns are provided on both front and back surfaces of the control circuit board 20, and an adhesive is applied to the back surface side (upper side in FIG. 1) of the control circuit board 20 or the bus bar constituent plate 10 to adhere the back surface side pattern to the bus bar upper surface. in this case,
Only the pattern having the same potential as the bus bar bonded to the control circuit board 20 is provided on the back surface side of the control circuit board 20.

An insulating adhesive is applied to the back surface of the control circuit board 20 or the upper surface of the bus bar component plate, and the insulating layer is formed between the control circuit board 20 and each bus bar by this adhesive. When the control circuit board 20 includes a through hole, the insulating adhesive is prevented from adhering to the through hole (details will be described later).

An adhesive is applied only to the rear edge portion of the control circuit board 20 and adhered to the upper surface of the bus bar. In this case, the bonding area is only the edge portion, and the control circuit board 20 and the bus bar are free from each other in the area inside thereof.
The stress is relieved accordingly.

In each of the above cases 1 and 2, the adhesive can be applied by printing, which can promote the efficiency and automation of the manufacturing process.

3) Mounting Step Using the through hole 22 provided in the control circuit board 20, the FET 30 is mounted as a semiconductor switching element on both the control circuit board 20 and the bus bar constituent plate 10.

As shown in FIG. 4, the FE used here
The T30 includes a substantially rectangular parallelepiped main body 32 and at least three terminals (a drain terminal, a source terminal 34, and a gate terminal 36, which are not shown). Of the terminals, the drain terminal is provided on the back surface of the main body 32, and the source terminal 3
4 and the gate terminal 36 project from the side surface of the main body 32 and extend downward.

Corresponding to the FET 30, a rectangular portion 22a into which the main body 32 of the FET 30 can be inserted is provided in each through hole 22 of the control circuit board 20, and the rectangular portion 22a.
Extending in a predetermined direction from the source terminal 34 of the FET 30.
And an extension portion 22b having a shape that allows insertion.
Then, the FET body 32 is provided through the rectangular portion 22a.
The drain terminal on the back surface of the FET is directly contacted with the upper surface of the input terminal bus bar 11 in the bus bar constituent plate 10 to mount the FET body 32 on the bus bar 11, and the source terminal 34 of the FET 30 is used as an output terminal through the extending portion 22b. The gate terminal 36 of the FET 30 is connected to the bus bar 12 and connected to an appropriate conductor pattern on the control circuit board 20.

That is, in this mounting process, the FET 30
Can be simultaneously mounted on both the control circuit board 20 and each bus bar from the upper side.
Compared to the method in which 0 is separately connected to both boards at a position between the busbar board and the control circuit board via wiring materials,
Assembly work efficiency is dramatically improved.

This mounting process can be easily performed by, for example, applying molten solder to each through hole 22 by printing or the like, and placing the FET 30 on the molten solder.

In carrying out this mounting process,
In advance, as shown in FIG. 4, the source terminal 34 and the gate terminal 3
It is more preferable to provide a level difference t between the control circuit board 6 and the control circuit board 6 that is substantially equal to the thickness of the control circuit board 20. If you do this,
Both terminals 3 regardless of the thickness of the control circuit board 20.
The respective terminals 34 and 36 can be mounted on the output terminal bus bar 12 and the control circuit board 20 as they are without causing undue deformation of the terminals 4 and 36, and the stress of each terminal after mounting is significantly reduced.

If there is a bus bar to be directly connected to the control circuit of the control circuit board 20 among the bus bars included in the bus bar component board 10, for example, as shown in part A of FIG. You may make it make a protrusion and solder the protrusion to the control circuit board 20 side.

4) Bending process control As shown in FIG. 6, the bus bar end portions (including at least the end portions 11a, 12a, 14a of the bus bars 11, 12, 14) protruding from the circuit board 20 to the left and right sides are shown in FIG. Bend upward to form a terminal connected to an external circuit. By performing such a bending step, it becomes possible to connect the external wiring member to each terminal from one direction, and the connecting work is simplified.

5) Housing mounting step (connector forming step 1) As shown in FIG. 7, a plurality of signal input terminals (in the figure, the end portions 14a of the signal input terminal bus bar 14 are arranged in a horizontal row). A housing 40 made of an insulating material such as synthetic resin is fixed to the periphery of the to form a connector. A protrusion 42 for engaging with a case 50 described later is formed on the side surface of the housing 40.

6) Separation Step The busbars in the busbar constituent plate 10 are separated from each other by a press or the like to complete a power circuit. Specifically, the connecting portion 18 exposed outside the control circuit board 20 may be cut and removed. By removing the connecting portion 18, the outer frame 16 is inevitably removed from the circuit structure. In the state after this separating step, the entire height dimension (thickness dimension) is very small, and the occupied area is suppressed to be substantially equal to the area of the control circuit board 20.
This circuit structure can be used by itself, but by further adding a case 50 and a heat dissipation member 60, which will be described later, it becomes possible to further enhance waterproofness and heat dissipation, and a vehicle power distributor or the like. It is possible to obtain a suitable circuit body.

The separating step is the same as the above step 3).
~ 5) may be performed before. However, when the busbar ends 11a, 12a, 14a forming the terminals are connected to the outer frame 16 or another busbar, the disconnecting step needs to be performed first.

7) Case mounting step (connector forming step 2) A case 50 made of an insulating material such as synthetic resin from the upper side of the circuit structure obtained in the disconnecting step of 6)
(FIG. 9). The case 50 has a shape that opens downward and covers the entire control circuit board 20 from above.
An opening for opening the FET 30 upward is provided in the center thereof, and a waterproof wall 52 is provided upright from the peripheral edge of the opening. That is, the waterproof wall 52 is the FE
It surrounds the region containing T30.

Both left and right edges of the case 50 (waterproof wall 52
A cylindrical housing 54 and a housing mounting portion 56, which open vertically, are integrally formed with the case 50 on both the left and right outer sides of. The housing 54 is formed at a plurality of positions, and individually surrounds the end portion 11a (input terminal) of the input terminal bus bar 11 and the end portion 12a (output terminal) of the output terminal bus bar 12, and a connector together with these terminals. Constitute. The housing mounting portion 56 is formed at a position corresponding to the housing 40 (a housing that surrounds the signal input terminal), and the housing 40 is inserted into the housing mounting portion 56 from below.
The bus bar and the control circuit board 20 are locked to the case 50 by the protrusion 42 on the side wall of the housing engaging with the upper end of the housing mounting portion 56.

In this structure, each terminal and the housing 4 are
It is possible to easily connect the terminal to an external circuit by connecting a connector provided at a terminal of a wire harness arranged in a vehicle to a connector configured with 0 and 54, for example. ing.

A plurality of fin covers 58 arranged side by side project downward from both front and rear ends of the case 50.

8) Heat dissipating member connecting step A heat dissipating member 6 as shown in FIG. 10 is formed on the lower surface of each bus bar.
The upper surface 64 of 0 is adhered and the two are united.

The heat dissipating member 60 is entirely made of a material having excellent thermal conductivity such as an aluminum-based metal and has a flat upper surface 6.
4, and a plurality of fins 62 arranged side by side project downward from the lower surface. The position of each fin 62 corresponds to the position of the fin cover 58 in the case 50, and by mounting the heat dissipation member 60, both ends in the longitudinal direction of each fin 62 are covered with the fin cover 58.

The adhesion between the heat dissipation member 60 and the bus bar is
For example, the following procedure is preferable.

An insulating adhesive made of epoxy resin is applied to the upper surface 64 of the heat dissipation member 60 and dried to form a thin insulating layer.

Overlaid on the insulating layer, an adhesive (for example, a grease-like one such as a silicone adhesive) that is softer and has higher thermal conductivity than the material forming the insulating layer is applied, or a bus bar The adhesive is applied to the side, and the bus bar is adhered by this adhesive.

Here, the insulating layer is not necessarily required, but by forming the insulating layer, it is possible to minimize the amount of expensive adhesive (adhesive that is soft and has excellent thermal conductivity) used and to ensure reliable electrical conductivity. Insulation can be secured. The insulating layer can also be formed, for example, by pasting an insulating sheet on the upper surface 64 of the heat dissipation member 60.

When the bus bar includes one to be grounded, the heat radiating member 60 may be screwed and fixed to the bus bar, and the heat radiating member 60 may be connected to the ground.

In addition to the adhesion between the bus bar and the heat radiating member 60, for example, an engaging portion for engaging the case 50 and the heat radiating member 60 with each other is provided, and the heat radiating member 6 is also provided in the case 50.
It is preferable to fix 0. Further, the case 50
By interposing a sealing material made of silicon rubber or the like between the heat dissipation member 60 and the heat dissipation member 60, the waterproofness of the circuit structure is further enhanced.

9) Potting Step A cover 70 as shown in FIG. 11 is provided on the upper end of the waterproof wall 52.
The waterproof wall 52 is hermetically sealed by covering them with each other and joining them (for example, by vibration welding). Further, as shown in FIG. 12, the inside of the waterproof wall 52 is sealed by injecting an appropriate potting agent from the potting agent inlet 72 provided in the cover 70. As a result, the waterproof effect of the circuit structure is further enhanced.

In the circuit structure manufactured as described above, the power source is supplied to the input terminal (the end portion 11a of the input terminal bus bar 11) and the output terminal (the output terminal bus bar 12).
By connecting an electric load to the end portion 12a) of the power supply circuit, a power distribution circuit that distributes power from the power source to an appropriate electric load is constructed, and the operation of the FET 14 provided in the middle of the power distribution circuit is controlled by the control circuit. By being controlled by the control circuit incorporated in the substrate 20, on / off control of energization of the power distribution circuit is executed.

When the insulating adhesive is applied to the back surface of the control circuit board 20 or the upper surface of the bus bar component plate in the bonding step, the insulating adhesive may be applied to only one of these surfaces. However, as shown in FIG. 13, control is performed on the upper surface of the bus bar (only the input terminal bus bar 11 is shown in the figure as an example, but the same applies to other bus bars. The same applies to the following). If the adhesive 80 is applied to both the lower surface of the end portion of the circuit board 20, more reliable adhesion can be achieved.

If the control circuit board 20 has the through-hole connecting portion 24 as shown in FIG. 14, by arranging the adhesive 80 while avoiding the through-hole connecting portion 24 as shown in FIG. The control circuit board 20 and the bus bar 11 can be bonded while ensuring the reliability of electrical connection.

This point is the same when the bus bar 11 and the control circuit board 20 are electrically connected by soldering using the through hole connecting portion 24. For example, in FIG.
When the difference between the width of the through hole connecting portion 24 and the width D of the bus bar 11 is small as shown in (a) (the bus bar width D is relatively small), the adhesive 80 is provided only before and after the through hole connecting portion 24. If the bus bar width D is sufficiently large as shown in FIG. 7B, the adhesive 80 may be arranged so as to surround the through hole connecting portion 24.

When the side surface of the bus bar 11 and the lower surface of the control circuit board 20 are electrically connected by soldering 26 as shown in FIG. It is preferable to arrange 80.

The circuit structure according to the present invention is not limited to the one manufactured by the above method, and at least the semiconductor switching element is mounted on the bus bar in a state where the bus bar is adhered to the surface of the control circuit board. By having it, it is possible to enjoy the effects of simplifying and thinning the overall configuration.

Further, the semiconductor switching element used in the present invention is not limited to the above-mentioned FET, but includes a conduction terminal connected to the power circuit side formed by the bus bar and a control terminal connected to the control circuit board 20 side. Any material can be widely applied.

[0077]

As described above, according to the present invention, a plurality of bus bars constituting a power circuit are bonded to the surface of the control circuit board,
Since the semiconductor switching element is mounted on both the bus bar and the control circuit board, a power circuit including the semiconductor switching element can be constructed with a simple and thin structure, and the heat dissipation of the semiconductor switching element can be improved. There is an effect that an excellent circuit structure can be provided.

Further, in manufacturing this circuit structure, the metal bus bar component plate having a shape in which the bus bars are connected to each other and the control circuit board are bonded, and then the semiconductor switching elements are mounted and the bus bars are separated from each other. As a result, the circuit structure can be efficiently manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing a bus bar component plate and a control circuit substrate used in a method for manufacturing a circuit component according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state where the bus bar constituent plate and a control circuit board are bonded together.

FIG. 3 shows an FET on the bus bar constituent plate and the control circuit board.
It is a perspective view which shows the state which mounted.

FIG. 4 is an enlarged cross-sectional perspective view showing a mounted state of the FET.

FIG. 5 is a perspective view showing a direct connection point between the bus bar component plate and a control circuit board.

FIG. 6 is a perspective view showing a state in which an end portion of a predetermined bus bar in the bus bar constituent plate is bent upward.

FIG. 7 is a perspective view showing a state in which a housing is provided around an end portion of a bent signal input terminal bus bar to form a connector.

FIG. 8 is a perspective view showing a state in which the outer frame is removed from the busbar component plate to separate the busbars from each other.

FIG. 9 is a perspective view showing a state in which a case is mounted on the control circuit board and the bus bar.

FIG. 10 is a perspective view showing a circuit structure body to which the case is mounted and a heat dissipation member mounted to the circuit structure body.

FIG. 11 is a perspective view showing a circuit structure body to which the heat dissipation member is mounted and a cover mounted to a waterproof wall of the case.

FIG. 12 is a perspective view showing a step of injecting a potting agent from a potting injection port of a mounted cover.

FIG. 13 is a cross-sectional view showing an example of an adhesive application region in the adhering step.

14A is a bottom view showing an example of an adhesive application area when a through-hole connecting portion is present in a control circuit board in the bonding step, and FIG. 14B is a sectional view taken along line AA of FIG. Is.

15 (a) and 15 (b) are bottom views showing an example of applying an adhesive while avoiding a through hole connecting portion.

FIG. 16 is a bottom view showing an example in which an adhesive is applied while avoiding a soldering connection portion.

[Explanation of symbols]

10 busbar components Bus bar for 11 input terminals Bus bar for 12 output terminals 14 Bus bar for signal input terminal 16 outer frame 18 ties 20 control circuit board 22 Through hole 30 FET (semiconductor switching element) 32 FET body 34 Source terminal (energization terminal) 36 Gate terminal (control terminal) 40 housing 50 cases 52 waterproof wall 54 Housing formed in case 60 heat dissipation member 70 cover 72 Potting agent inlet

Continued front page    (72) Inventor Takahiro Onizuka             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Isao Isshio             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Ryuji Nakanishi             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Koichi Takagi             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Chen Noboru             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. F-term (reference) 5G361 BA01 BA04 BB03

Claims (20)

[Claims] 1. A plurality of bus bars forming a power circuit, a semiconductor switching element provided in the power circuit, and a control circuit board for controlling driving of the semiconductor switching element, wherein the bus bars are substantially coplanar. Adhered to the surface of the control circuit board in a lined up state, and
A circuit structure in which the semiconductor switching element is mounted on both the bus bar and a control circuit board. 2. The circuit structure according to claim 1, wherein a through hole is provided in the control circuit board, and the semiconductor is provided on a surface of the control circuit board opposite to a surface to which the bus bar is adhered. A circuit structure, wherein a part of terminals of a switching element is connected, and another terminal of the semiconductor switching element is connected to the bus bar through the through hole. 3. The circuit structure according to claim 2, wherein the semiconductor switching element has a current-carrying terminal on a back surface of the main body, and the control circuit board has a size into which the main body of the semiconductor switching element can be inserted. Through holes are provided,
A circuit structure in which the main body of the semiconductor switching element is mounted on the bus bar in a state where the current-carrying terminals on the back surface of the main body of the semiconductor switching element are in contact with the bus bar through the through holes. 4. The circuit structure according to claim 1, wherein a plurality of bus bars project laterally from the control circuit board to form a terminal connected to an external circuit. A circuit structure characterized by the above. 5. The circuit structure according to claim 4, wherein the bus bars forming the terminals are bent in the same direction and substantially orthogonal to the control circuit board. Construct. 6. The circuit structure according to claim 5, wherein a connector is formed by providing a housing made of an insulating material around the terminals. 7. The circuit structure according to claim 6, further comprising a case made of an insulating material for accommodating the bus bar and the control circuit board, and at least a part of the housing being formed integrally with the case. A circuit structure characterized by. 8. The circuit structure according to claim 7, wherein a waterproof wall surrounding a region including the semiconductor switching element is provided upright in the case, and an opening of the waterproof wall is covered with a cover. A circuit structure characterized in that the inside thereof is sealed with a potting agent. 9. The circuit structure according to claim 4, wherein the terminal includes an input terminal connected to a power source and a plurality of output terminals connected to an electric load, and the plurality of terminals are provided. The bus bar of (1) constitutes a power distribution circuit that outputs the electric power supplied to the input terminal from the output terminal to each of the electric loads. 10. The circuit structure according to claim 4, wherein the terminal includes a signal input terminal to which a command signal is input from the outside, and a bus bar constituting the signal input terminal controls the control. A circuit structure, which is electrically connected to a control circuit provided on a circuit board. 11. The circuit structure according to claim 1, further comprising a heat dissipation member provided on a side opposite to the control circuit board with the bus bar interposed therebetween, and the heat dissipation member having an insulating layer interposed therebetween. A circuit structure, wherein the bus bar is connected. 12. A circuit structure including a plurality of bus bars forming a power circuit, a semiconductor switching element provided in the power circuit, and a control circuit board for controlling the driving of the semiconductor switching element is manufactured. A busbar forming step of forming a metal busbar constituting plate having a shape in which the busbars are connected to each other, an adhering step of adhering the busbar constituting plate and the control circuit board, and the method after the adhering step. A circuit structure including a mounting step of mounting a semiconductor switching element on both a predetermined bus bar included in the bus bar constituent plate and the control circuit board, and a separation step of separating the bus bars from each other after the bonding step. Manufacturing method. 13. The method of manufacturing a circuit structure according to claim 12, wherein the busbar forming plate formed in the busbar forming step has busbar forming parts arranged inside an outer frame, and at least the busbar forming parts are arranged. A part has a shape connected to the outer frame, the bonding step is for bonding the control circuit board to a portion inside the outer frame of the bus bar component plate, and the separating step is the outer frame. A method of manufacturing a circuit structure, comprising a step of cutting between a frame and the bus bar constituent part. 14. The method of manufacturing a circuit structure according to claim 13, wherein the busbar forming plate formed in the busbar forming step has a portion that directly connects the busbar forming portions, and this portion is the A method of manufacturing a circuit structure, having a shape positioned outside an area to which a control circuit board is bonded. 15. The method of manufacturing a circuit structure according to claim 12, wherein the adhering step includes a step of applying an adhesive on the control circuit board by printing. Method for manufacturing circuit structure. 16. The method of manufacturing a circuit structure according to claim 12, wherein the mounting step is performed on a surface of the control circuit board opposite to a surface to which the bus bar is bonded. A circuit structure characterized in that a part of terminals of a semiconductor switching element is connected, and another terminal of the semiconductor switching element is connected to a bus bar through a through hole provided in the control circuit board. Production method. 17. The method for manufacturing a circuit structure according to claim 16, wherein, before the mounting step, a terminal of the semiconductor switching element connected to the control circuit board and a terminal connected to the bus bar are provided in advance. A method of manufacturing a circuit structure, characterized in that a step substantially equal to the thickness of the control circuit board is provided between the steps. 18. The method of manufacturing a circuit structure according to claim 12, wherein a plurality of bus bars protruding laterally from the control circuit board in the state after the bonding step have the same direction. And a bending step of forming a terminal connected to an external circuit by bending in a direction substantially orthogonal to the control circuit board. 19. The method for manufacturing a circuit structure according to claim 18, further comprising a connector forming step of forming a connector by providing a housing made of an insulating material around the terminals after the bending step. Method for manufacturing circuit structure. 20. The method for manufacturing a circuit structure according to claim 12, further comprising the step of connecting the bus bar bonded to the control circuit board to a heat dissipation member via an insulating layer. And a method for manufacturing a circuit structure.