JP2003298011A - Power distribution box - Google Patents

Abstract

(57) [Summary] [Problem] To reduce the number of parts of a power distribution box and downsize it. SOLUTION: A power supply side bus bar 3 connected to a power supply side.
And a plurality of FET modules in which a plurality of FETs that supply power to a load in a state where the input terminal is connected to the power supply side bus bar 3 and the output terminal 9 faces in the same direction are mounted on a bare chip as a single package. 8, a power supply side circuit board 4 which is arranged on the same plane as the power supply side bus bar 3 and on which a plurality of FET modules 8 are mounted, and a connection terminal 11 which is connected to an output terminal 9 of the FET module 8. A load-side circuit board that is mounted on the FET module and supplies power to the load;

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a power distribution box for an automobile.

[0002]

2. Description of the Related Art A power distribution box for an automobile is used for the purpose of controlling each load such as a lamp. A relay and a control unit are arranged between a power side bus bar and a load side bus bar. The parts are arranged inside the case. However, the relay cannot perform complicated control because it simply turns ON / OFF the power supply to the load. Therefore, for example, when it is necessary to perform PWM control of the lamp when the power supply voltage becomes 42 V, it is necessary to use a semiconductor. In addition to such a situation, it is also made to make a relay a semiconductor.

[0003]

When semiconductors are used or relays are made into semiconductors, it is necessary to lead the power supply line to the circuit board on which these are mounted. However,
Since the power line occupies a large space in the pattern of the circuit board, there is a problem that the circuit board becomes large and the power distribution box also becomes large.

Further, since an input terminal for connecting the bus bar on the power source side and the circuit board and an output terminal for outputting to the load side from the circuit board are required, this also increases the size of the power distribution box.

The present invention has been made in consideration of such problems, and an object thereof is to provide a power distribution box which can reduce the number of parts and can be downsized.

[0006]

According to a first aspect of the present invention, there is provided a power distribution box in which the power supply side bus bar is connected to the power supply side and the input terminal is connected to the power supply side bus bar and the output terminals are oriented in the same direction. FEs that supply power to the load while in a state
A plurality of FET modules in which T is mounted as a bare chip into one package, a power supply side circuit board on which the plurality of FET modules are mounted and arranged on the same plane as the power supply side bus bar, and an output terminal of the FET module It is characterized in that it has a connection terminal to be connected, is mounted on the FET module, and is provided with a load side circuit board for supplying power to the load.

In this power distribution box, a plurality of FETs for supplying power to the load are bare-chip mounted to form an FET module, and the FET module is mounted on the power supply side circuit board. Therefore, relays, input terminals, and output terminals are provided. Is unnecessary, the number of parts can be reduced, and the power distribution box can be downsized.

Further, since power is supplied directly to the FET module from the power source side bus bar, it is not necessary to route a power line having a large current value to the power source side circuit board.
Therefore, the power supply side circuit board can be made small.

Further, since the power supply side circuit board is arranged on the same plane as the power supply side bus bar, either the power supply side circuit board or the power supply side bus bar becomes unnecessary, and the thickness can be reduced.

Further, since the load-side circuit board is mounted on the FET module, the space for the load-side circuit board is unnecessary, and the size can be further reduced.

A second aspect of the invention is the power distribution box according to the first aspect, characterized in that a concave portion into which the power source side bus bar is inserted is formed on the bottom surface of the FET module.

In this power distribution box, the bus bar on the power supply side is inserted into the recess on the bottom surface of the FET module,
The thickness of the bus bar on the power supply side is absorbed. For this reason, the bus bar on the power source side has no thickness, and the bus bar can be made thinner.

[0013]

1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a perspective view of an FET module.

As shown in FIG. 1, the power distribution box of this embodiment is formed by a case body 1 formed by aluminum die casting into a rectangular box shape and a corresponding main cover 2 having a rectangular box shape. Inside the case, the power source side bus bar 3 connected to the power source side, the power source side circuit board 4, the load side circuit board 5, and the load side bus bar 6 connected to the load side are housed in a stacked state. There is.

Parallel thin rib protrusions 1a are formed on the bottom surface of the case body 1 for promoting heat dissipation and improving strength, and the power source side bus bar 3 is provided on the rib protrusions 1a via an elongated insulating sheet 7. It is fixed to. In order to fix the power source side bus bar 3 to the rib protrusion 1a, the rib protrusion 1a, the insulating sheet 7 and the power source side bus bar 3 are formed with a plurality of screw holes 1b, 7b, 3b through which screws penetrate.

In this embodiment, the bus bar 3 on the power source side
Are arranged so that the two are parallel to each other. In order to secure heat radiation from the FET module 8 described later,
It is possible to fix the case body 1 to the heat dissipation plate, or to mold the case body 1 with another highly heat-conductive metal.

The power supply side circuit board 4 is disposed between two parallel power supply side bus bars 3. Therefore, the power supply side circuit board 4 is arranged on the same plane as the power supply side bus bar 3.
The power circuit board 4 has a plurality of FET modules 8
Are mounted, and a driver circuit for sending a control signal to the FET module 8 is formed. The power source side circuit board 4 has a housing 4a into which a connector is inserted.
Are formed in an upright shape, and by inserting the housing 4a into the load side circuit board 5, the second insulating plate 12 and the housing holes provided at corresponding positions of the main cover 2, these are arranged on the power supply side circuit board. It is possible to position relative to 4.

The FET module 8 has a structure in which several FETs (not shown) are mounted inside in a bare chip and housed in one package. Each FET module 8
In the inside of, the bare FET is mounted so that the input terminal of the housed FET is connected to the bus bar 3 on the power source side. Further, each FET module 8 has an output terminal 9 corresponding to an input terminal, but the output terminal 9 is pulled out from the FET module 8 in the same direction (upward in this embodiment). Has been. A tuning fork type terminal is used as the output terminal 9.

Further, each FET module 8
Has screw holes 8b and 8c for screwing. The screw hole 8b is provided at a position corresponding to the screw holes 3b, 7b, 1b of the power source side bus bar 3, the insulating sheet 7 and the rib protrusion 1a, and the FET module 8 is connected to the power source side bus bar 3, the insulating sheet 7 and the rib protrusion. It is used for fixing to the case body 1 via 1a. On the other hand, the screw hole 8c is used to fix the FET module 8 to the power source side circuit board 4.

In this embodiment, the plurality of FET modules 8 are mounted on the power supply side circuit board 4 in two rows. A recess 8a is formed on the bottom surface of each FET module 8 along the length direction. This recess 8
a is formed to have a size similar to the thickness and width of the power source side bus bar 3. In addition, the FET module 8
Are mounted on the power-supply-side circuit board 4 in a line, the recesses 8a of the adjacent FET modules 8 are brought into communication with each other. The bus bar 3 on the power source side is inserted into the communicating recess 8a. As a result, the plate thickness of the power source side bus bar 3 is absorbed. Further, it is possible to prevent the position shift between the power source side bus bar 3 and the FET module 8.

On the bottom of each FET module 8, the FET
Is exposed, and this input terminal comes into contact with the power source side bus bar 3 that has entered the recess 8a on the bottom surface. By this contact, the bus bar 3 on the power source side to the FET module 8
The power can be directly supplied to. Therefore,
It is not necessary to route the power line to the power supply side circuit board 4.

The load side circuit board 5 is arranged by being placed on the FET module 8 mounted on the power source side circuit board 4. In this case, the load side circuit board 5 and the FET
The first insulating plate 10 is sandwiched between the module 8 and the module 8.

A connection terminal 11 corresponding to the output terminal 9 of the FET module 8 is inserted into the load side circuit board 5 so as to stand upright. A tuning fork type terminal is used as the connection terminal 11 similarly to the output terminal 9 of the FET module 8. The tuning fork type terminal is provided with a slit, and therefore the fuse 1 is connected to the corresponding output terminal 9 and connection terminal 11.
The FET module 8 and the load-side circuit board 5 can be connected by simply inserting the plate-shaped terminals 14a (see FIG. 2) at both ends of the connector 4, and the connection work can be performed easily. The output terminal 9 of the FET module 8 and the connection terminal 11 of the load-side circuit board 5 may have a shape other than the tuning fork terminal, for example, a connector terminal shape.
It is possible to connect the connector. Furthermore, on the surface of the load-side circuit board 5, terminals 13 for connectors are provided upright.

A second insulating plate 12 is placed on the load side circuit board 5. The second insulating plate 12 is formed with a slit 12a through which the connecting terminal 11 of the load side circuit board 5 pierces and penetrates, and the connecting terminal 11 is extracted above the second insulating plate 12. ing. The load side bus bar 6 is installed on the second insulating plate 12 to supply power to a load such as a lamp.

The main cover 2 is put on the case body 1. On the upper surface of the main cover 2, fuse housings 15 into which the fuses 14 are inserted are formed in left and right rows, respectively. A connector housing 16 into which a connector is inserted is formed between the fuse housings 15. In this main cover 2,
The upper cover 17 is appropriately covered.

In the power source side bus bar 3 of this embodiment, a plurality of standing pieces 3d are formed. Slits 10d, 5d, 12d corresponding to the standing piece 3d
, The first insulating plate 10, the load-side circuit board 5, and the second insulating plate 12 are formed. At the time of assembling the power distribution box, it is fixed to the case body 1 by the power side bus bar 3 screw, and in this fixed state, the upright piece 3d is inserted into the corresponding slits 10d, 5d, 12d, so that the first insulation Board 10, load side circuit board 5 and second insulating board 1
2 can be positioned, and the displacement of these members in the stacked state can be prevented.

In such an embodiment, the FET module 8 in which a plurality of FETs are mounted on a bare chip is used, and
To mount the ET module 8 on the power supply side circuit board 4,
No need for relays or power input / output terminals. Also, FE
Since the power is supplied directly to the T module 8 from the power supply side bus bar 3, the power supply side circuit board 4 does not require an input terminal. These reduce the number of parts,
Assembling becomes simple and the power distribution box can be downsized.

Furthermore, since the power is supplied directly from the power source side bus bar 3 to the FET module 8, it is not necessary to route a power line having a large current value to the power source side circuit board 4. Therefore, the power supply side circuit board 4 can be made small.

Further, since the power source side circuit board 4 is arranged on the same plane as the power source side bus bar 3, the power source side circuit board 4,
The thickness of either one of the power source side bus bar 3 is unnecessary.
Therefore, it is possible to reduce the thickness.

Furthermore, by placing the load-side circuit board 5 on the FET module 8, the space for disposing the load-side circuit board 5 is unnecessary, and therefore the size can be further reduced.

Furthermore, since the power source side bus bar 3 is inserted into the recess 8a on the bottom surface of the FET module 8, the thickness of the power source side bus bar 3 is absorbed, and the thickness can be further reduced.

[0032]

According to the power distribution box of the invention of claim 1,
Since an FET module in which a plurality of FETs are mounted on a bare chip is used and this FET module is mounted on the power supply side circuit board, a relay, an input terminal and an output terminal are not required, the number of parts can be reduced, and the power distribution box can be made small. It is possible and easy to assemble.

Further, since the power is supplied directly from the power source side bus bar to the FET module, it is not necessary to route a power line having a large current value to the power source side circuit board.
The power supply side circuit board can be made small.

Further, since the power supply side circuit board is arranged on the same plane as the power supply side bus bar, either the power supply side circuit board or the power supply side bus bar becomes unnecessary, and the thickness can be reduced.

Further, since the load side circuit board is mounted on the FET module, the space is not required and the size can be further reduced.

According to the power distribution box of the invention of claim 2, F
Since the power source side bus bar is inserted into the concave portion of the bottom surface of the ET module, the thickness of the power source side bus bar is absorbed, and the thickness can be further reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an entire embodiment of the present invention.

FIG. 2 is a perspective view of an FET module.

[Explanation of symbols]

3 Power side bus bar 4 Power supply side circuit board 5 Load side circuit board 6 Load side bus bar 8 FET module 8a recess 9 output terminals 11 connection terminals

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuya Suzuki             1500 Onjuku, Susono City, Shizuoka Prefecture Yazaki Parts Co., Ltd.             Within F-term (reference) 5G361 BA01 BA03 BB01 BC01

Claims (2)

[Claims] 1. A power source side bus bar connected to a power source side,
A plurality of FET modules in which a plurality of FETs for supplying power to a load with the input terminals connected to the bus bar on the power supply side and the output terminals facing the same direction are bare-chip mounted into one package, and the power supply side A power supply side circuit board on which the plurality of FET modules are mounted and arranged on the same plane as the bus bar, and a connection terminal which is connected to the output terminal of the FET module, are mounted on the FET module, and a power supply is supplied to the load. And a load-side circuit board for supplying the power. 2. The power distribution box according to claim 1, wherein the bottom surface of the FET module is formed with a recess into which the power-side bus bar is inserted.