JP2003224918A - Circuit structure - Google Patents

Abstract

(57) [Problem] To maintain a good mounting state of the circuit element while reducing the thickness of a circuit structure on which the circuit element is mounted on a bus bar. SOLUTION: A plurality of bus bars 11 to 14 made of a flat metal plate are adhered to a surface of a flexible sheet-shaped insulating base material 20 in a state of being arranged on substantially the same plane, and a specific bus bar is provided. The circuit element 30 is mounted on the bus bar so as to straddle between 11A and 13 to constitute a power circuit. At a position displaced in a direction orthogonal to the arrangement direction of the specific bus bars 11A and 13 from the arrangement position of the circuit element 30, a flexure suppressing portion 11e is extended from the bus bar 11A in a direction substantially parallel to the arrangement direction, and this flexure suppression is performed. The part 11e suppresses the bending and deformation of the insulating base material at a portion between the specific bus bars 11A and 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit structure for forming a power distribution circuit or the like in a vehicle.

[0002]

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

Furthermore, in recent years, in order to realize miniaturization and high-speed switching control of such an electric connection box, a circuit structure incorporating a circuit element such as an FET instead of the relay has been developed.

For example, in Japanese Unexamined Patent Publication No. 2001-268785, an insulating case made of synthetic resin or the like is molded around a plurality of bus bars arranged on substantially the same plane to be integrated as a whole, and an appropriate bus bar is mounted on the bus bar. A semiconductor switching element such as an FET is mounted on the power circuit to form a power circuit, and a control circuit board is arranged at a distance from the insulating case substantially parallel to the insulating case, and the control circuit board and each of the semiconductor switching elements are arranged. There is disclosed a power distributor which is connected to control the driving of the semiconductor switching element by a control circuit incorporated in the control circuit board.

[0005]

The power distributor disclosed in the above publication has a structure in which busbars arranged on substantially the same plane are integrated by an insulating case, and therefore has a structure as compared with a conventional electric junction box. Although it is simplified, there is a limit to its thinness. Therefore, the applicant
A technique for producing a circuit structure by adhering the bus bar to the surface of a sheet-shaped insulating base has been devised.

An example thereof is shown in FIG. In the figure, an input terminal bus bar 111 and an output terminal bus bar 112
A large number of bus bars including
No. 0 is bonded to one surface (lower surface in the illustrated example). A window 122 for mounting the FET is formed on the insulating base 120, and the bus bar 111 for the input terminal is provided from the top of the figure through the window 122.
And FET3 so as to straddle the output terminal bus bar 112.
0 is implemented.

The FET 30 includes a main body 32 having a substantially rectangular parallelepiped shape,
A drain is exposed on the lower surface of the main body 32, including a terminal protruding from the main body 32 (source terminal 34 is shown in the figure). The bus bar 1 is connected so that the drain contacts the upper surface of the input terminal bus bar 111.
The FET body 32 is mounted on 11 and the source terminal 34 is mounted on the output terminal bus bar 112.

According to such a circuit structure, it is possible to form a power distribution circuit including the FET 30 with a thin structure. Specifically, when the FET 30 is on, the electric power input to the input terminal bus bar 111 is the FET.
Is supplied to the output terminal bus bar 112 through
When the ET 30 is off, the bus bars 111 and 112 are electrically disconnected.

However, in such a circuit structure having a thin structure, a portion where the bus bar is not adhered (see, for example, FIG. 1).
In FIG. 5, the insulating sheet 120 is easily bent at the portion between the input terminal bus bar 111 and the output terminal bus bar 112) (see the chain double-dashed line in the figure), whereby the soldered portion between the FET 30 and the bus bar 111, 112 is formed. May peel off.

In view of the above circumstances, it is an object of the present invention to keep the mounted state of the circuit element in good condition while reducing the thickness of the circuit assembly in which the circuit element is mounted on the bus bar.

[0011]

Means for Solving the Problems As a means for solving the above problems, the present invention has a sheet shape having flexibility in a state where a plurality of bus bars made of a flat metal plate are arranged on substantially the same plane. A circuit structure body, which is adhered to the surface of an insulating base material and has a power circuit configured by mounting a circuit element on the bus bar so as to straddle between specific bus bars, the surface of the insulating base material. The bus bar adhered to, extends in a direction substantially parallel to the arrangement direction of the specific bus bar at a position deviated from the arrangement position of the circuit element in a direction orthogonal to the arrangement direction of the specific bus bar, and between the specific bus bars. In this portion, a flexure suppressing bus bar that suppresses flexural deformation of the insulating base material is included.

In this configuration, since the bus bar for circuit configuration is adhered to the surface of the insulating base material, the height dimension (thickness dimension) of the entire circuit configuration is much smaller than that of the conventional one, and it is significantly thin. Is achieved. Moreover, due to the rigidity of the deflection suppressing bus bar extending in a direction substantially parallel to the arrangement direction of the specific bus bars at a position deviated from the arrangement position of the semiconductor switching elements in the direction orthogonal to the arrangement direction of the specific bus bars, Since the sheet-shaped insulating base material is suppressed from being flexibly deformed in the portion between, it is possible to prevent the mounting portion of the circuit element on the bus bar from being peeled off due to the flexural deformation, and the mounting state is Keeps good.

Here, as the circuit element, one that can be mounted on the surface of the bus bar to form a power circuit, for example, F
Various types of transistors such as ET, diodes, resistors, etc. are applicable.

Further, the flexure suppressing busbar may be provided exclusively for flexure suppressing of the insulating base material, but at least one of the specific busbars is in a direction substantially parallel to a direction in which the specific busbars are arranged. If the structure is extended to double as the flexure suppressing bus bar, the above effect can be obtained with a simple structure without increasing the number of bus bars.

The insulating base material may be a simple insulating sheet, but the insulating base material is used as a control circuit board on which a control circuit for controlling the driving of the circuit elements is printed, and both the control circuit board and the bus bar are provided. With the configuration in which the circuit element is mounted, it is not necessary to newly install the control circuit board, and the configuration is further simplified. That is, as compared with the conventional configuration in which the control circuit board is provided separately from the circuit configuration body including the bus bar, the entire configuration is significantly thinned and simplified.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. Here, a case where a circuit distributor according to the present invention is used to manufacture a power distributor having a power distribution circuit that distributes power supplied from a common power source mounted on a vehicle or the like to a plurality of electric loads will be described. Although shown, the use of the circuit structure according to the present invention is not limited to this, and it 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. Also, the manufacturing method is not limited to the following.

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 in its inner area, a plurality of input terminal bus bars 11 that form input terminals and a plurality of outputs that form output terminals. 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.

Further, as shown in FIGS. 1, 13 and 14, a relay bus bar 13 is interposed between the specific input terminal bus bar 11A and output terminal bus bar 12A.

The busbar-constituting plate 10 can be easily formed, for example, by punching a single metal plate by pressing. However, in the present invention, each bus bar may be individually bonded to the insulating base material.

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 an FET described later.
A circuit that includes a control circuit that controls the switching operation of the (circuit element) 30. For example, a normal printed circuit board (a printed circuit board on which conductors that form the control circuit are printed and wired)
It is preferable to use a thin sheet having the same structure as the above and formed into a flexible thin sheet. In the illustrated example, a sheet-shaped control circuit board 20 having an extremely small thickness (for example, 0.3 mm) is used, and a plurality of through holes 22 are provided at appropriate places on the control circuit board 20. The through hole 22 is formed in the FE
This is for mounting the T30 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 in particular, 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).

3) Mounting Step Using the through holes 22 provided in the control circuit board 20, circuit elements (FET 30 in the illustrated example) are mounted on both the control circuit board 20 and the bus bar constituent plate 10.

The FE used here, as shown in FIG.
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. By this step, F is formed so as to straddle the input terminal bus bar 11 and the corresponding output terminal bus bar 12.
With the ET 30 mounted, a power distribution circuit is constructed in which electric power is supplied from the input terminal bus bar 11 to the output terminal bus bar 12 via the FET 30 serving as a switch means.

The specific input terminal bus bar 11A and output terminal bus bar 12 shown in FIGS. 1, 13 and 14 are also provided.
Regarding A and the relay bus bar 13 interposed between them,
The FET 30 is mounted so as to straddle the input terminal bus bar 11A and the relay bus bar 13, and the FET 30 is mounted so as to straddle the relay bus bar 13 and the output terminal bus bar 12A. The electric power input to the output terminal bus bar 12A is sequentially supplied to the output terminal bus bar 12A via the FET 30 → relay bus bar 13 → FET 30.

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

In order to carry out such a mounting process, it is more preferable to provide a step t between the source terminal 34 and the gate terminal 36, which is substantially equal to the thickness of the control circuit board 20, as shown in FIG. preferable. When there is a bus bar to be directly connected to the control circuit of the control circuit board 20 in the bus bar included in the bus bar component board 10, for example, an appropriate protrusion is formed from the bus bar as shown in part A of FIG. Alternatively, the protrusion may be exposed and soldered to the control circuit board 20 side.

4) Bending process control As shown in FIG. 6, the end portions of the bus bars (at least including 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.

5) Housing mounting process As shown in FIG. 7, a synthetic resin or the like is provided around 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). The housing 40 made of the above insulating material is fixed 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.

7) Case mounting step 6) A case 50 made of an insulating material such as synthetic resin from the upper side of the circuit structure obtained in the separating step.
(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 cover mounting wall 52 is provided upright from the peripheral edge of the opening. That is, this cover mounting wall 5
2 surrounds the region including the FET 30.

At the left and right edges of the case 50 (at the left and right outer sides of the cover mounting wall 52), a cylindrical housing 54 opening vertically and a housing mounting portion 56 are provided.
It is formed integrally with 0. The housing 54 is formed at a plurality of locations, and the end portion 11 of the input terminal bus bar 11 is formed.
a (input terminal) and an end portion 12 of the output terminal bus bar 12
a (output terminal) is individually surrounded, and a connector is configured with these terminals. The housing mounting portion 56 is
The housing 40 (a housing surrounding a signal input terminal)
Is formed at a position corresponding to
The housing 40 is inserted into the housing 40 from below, and the projection 42 on the side wall of the housing 40 engages with the upper end of the housing mounting portion 56 to lock the bus bar and the control circuit board 20 to the case 50.

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.

9) Potting Step A potting agent is injected into the inside of the cover attaching wall 52 from the upper end opening of the cover attaching wall 52 to seal the FET 30 in the potting agent. After that, the cover 70 as shown in FIG. 11 is put on the upper end of the cover mounting wall 52 and joined to each other (for example, by vibration welding) to seal the inside of the cover mounting wall 52. As a result, the waterproof effect of the circuit structure is further enhanced.

In the power distributor manufactured as described above, the input terminal (the end portion 11a of the input terminal bus bar 11) is supplied with the power source and the output terminal (the end portion 12a of the output terminal bus bar 12) is electrically loaded. By connecting the above, 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 board 20.
By being controlled by the control circuit incorporated in the power distribution circuit, on / off control of energization of the power distribution circuit is executed.

By the way, in the circuit structure shown here,
For example, in the state shown in FIG. 8, the control circuit board 20 is a thin sheet and is easily bent, and the bending is concentrated particularly on the portion where the bus bar is not arranged. Therefore, if no measures are taken, a bending with a large curvature occurs between the adjacent bus bars, so that the soldered portion between the FET 30 and both bus bars mounted over both bus bars peels off, resulting in a poor connection. May occur.

For example, there is a minute gap between the input terminal bus bar 11A and the relay bus bar 13 shown in FIGS. 1, 13, and 14, and these bus bars 11A, 13 are provided.
Since the FET 30 is mounted over the entire area, a large bending is generated between the busbars 11A and 13 so that the soldered portion between the busbars 11A and 13 and the FET 30 is peeled off, resulting in poor connection. May occur.

Therefore, in this embodiment, the FET
At a position deviated from the arrangement position of 30 in a direction orthogonal to the arrangement direction of the bus bars 11A and 13 (left and right direction in FIGS. 13A and 13B), the bus bars 11A and 13 extend in a direction substantially parallel to the arrangement direction, and A flexure suppressing busbar that suppresses flexural deformation of the insulating base material is included between the busbars. Specifically, the two-dot chain line in FIG. 1 and FIG.
As shown in (b) and FIG. 14 (b), from the end of the input terminal bus bar 11A to both bus bars 11A, 13A.
The bus bar for relay 13 along a direction substantially parallel to the arrangement direction of the
The bending restraint portion 11e is extended in a direction crossing the lateral side (to the left in FIG. 13B), and due to the rigidity of the bending restraint portion 11e, the bending restraint portion 11e between the input terminal bus bar 11A and the relay bus bar 13 is extended. Bending of the control circuit board 20 is suppressed. That is, the input terminal bus bar 1
1A is configured to also serve as a flexure suppressing bus bar.

According to this structure, the FET 3 caused by the bending of the control circuit board 20 has a simple structure in which the bending suppressing portion 11e is simply extended from the input terminal bus bar 11A.
A connection failure of 0 can be avoided in advance.

The deflection suppressing bus bar according to the present invention is not limited to the one extending from the input terminal bus bar 11A as described above, but may be, for example, a bus bar (both bus bars 11A that is completely independent of both bus bars 11A and 13A). , 13 are connected to both bus bars 11A and 13A.
You may arrange | position in the position which can suppress the bending of the control circuit board 20 between them. Further, the bending suppression target portion by the bending suppression bus bar may be appropriately set. For example, the bending suppression bus bar is arranged at a position that suppresses the bending between the input terminal bus bar 11 and the output terminal bus bar 12 shown in FIG. You may set it up.

The insulating base material is not limited to the one that constitutes the control circuit board 20 as in the above-described embodiment, and may be, for example, a simple insulating sheet to which each bus bar is adhered.

[0048]

As described above, according to the present invention, a plurality of busbars are adhered to the surface of a sheet-shaped insulating base material, and a circuit element is mounted so as to straddle between the specific busbars so that a power circuit is provided. Since it is a configured circuit structure, it can be made thinner. Moreover, the bus bar adhered to the surface of the insulating base material extends in a direction substantially parallel to the arrangement direction of the specific bus bar at a position deviated from the arrangement position of the circuit element in a direction orthogonal to the arrangement direction. Since a flexure suppressing busbar that suppresses flexural deformation of the insulating base material in the portion between the specific busbars is included,
By suppressing the flexural deformation, there is an effect that the mounted state of the circuit element can be kept good.

[Brief description of drawings]

FIG. 1 is a perspective view showing a bus bar component plate and a control circuit substrate used 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 having the heat dissipation member mounted thereon and a cover mounted on a cover mounting wall of the case thereof.

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 (a) is a plan view showing a busbar constituent plate to which the bending suppressing means according to the present invention is not applied, and FIG. 13 (b) is a plan view showing a busbar constituent plate to which the bending suppressing means according to the present invention is applied.

FIG. 14A is a plan view showing a circuit structure body to which the bending suppressing means according to the present invention is not applied, and FIG. 14B is a plan view showing a circuit structure body to which the bending suppressing means according to the present invention is applied.

FIG. 15 is a cross-sectional view showing a bent state in a circuit structure in which a bus bar is mounted on the surface of a thin sheet insulating base material and an FET is mounted on the surface thereof.

[Explanation of symbols]

11A bus bar for input terminals 11A Bus bar for input terminals (a bus bar that is a specific bus bar on which a circuit element is mounted and also serves as a deflection suppressing bus bar) 11e Deflection suppressing section 12 Output terminal bus bar 13 Relay bus bar (circuit element is mounted Bus bar for signal input terminal 20 control circuit board 30 FET (circuit element)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeki Yamane             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. F-term (reference) 5G361 BA04 BA07 BB02 BC03

Claims (3)

[Claims] 1. A plurality of busbars made of a flat metal plate are adhered to the surface of a flexible sheet-like insulating base material in a state of being arranged on substantially the same plane, and between specific busbars. A circuit configuration body in which a circuit element is mounted on the bus bar so as to straddle the power circuit, and the bus bar adhered to the surface of the insulating base material has the above-mentioned identification from the position where the circuit element is disposed. For suppressing bending of the insulating base material that extends in a direction substantially parallel to the direction in which the bus bars are displaced in a direction orthogonal to the direction in which the bus bars are arranged and suppresses the insulating base material from bending and deforming in a portion between the specific bus bars. A circuit structure including a bus bar. 2. The circuit structure according to claim 1, wherein at least one of the specific busbars extends in a direction substantially parallel to a direction in which the specific busbars are arranged, and also serves as the deflection suppressing busbar. A circuit structure characterized by. 3. The circuit structure according to claim 1, wherein the insulating base material is a control circuit board on which a control circuit for controlling the driving of the circuit element is printed, and the control circuit board and the bus bar. A circuit structure in which the circuit element is mounted on both sides.