JPH10135582A - Electronic circuit unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently radiate the heat developed by an exothermic electronic part by rationally using a bus bar. SOLUTION: An exothermic electronic part 14 is fixed on the substrate 11 of an electronic circuit. In the electronic circuit unit 10 in which a bus bar 12 is arranged on the substrate 11, a specific surface of the electronic part 14 may be brought into face to face contact with a specific surface of this bus bar 12 for radiating the heat developed by the electronic part 14 by transferring heat face to face to the bus bar 12. In such a constitution, a heat radiation part 12a is provided near a specific surface of the bus bar 12 so as to form a specific terminal (D) of the electronic part 14 on the specific surface of the electronic part 14 so that the specific terminal (D) may be connected to the bus bar 12 when the specific surface of the electronic part 14 is brought into face to face contact with the specific surface of the electronic part 14 to be fixed. Through these procedures, the bus bar 12 is brought into contact with printed pattern circuits 13 formed on the substrate 11 to be arranged for branching the circuits from the bus bar 12 to the printed pattern circuits 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit unit capable of efficiently radiating heat generated by heat-generating electronic components by using a bus bar rationally.

[0002]

2. Description of the Related Art In an electric connection box used for a wire harness for an automobile, an electronic circuit unit for controlling electric components is incorporated. As shown in FIG.
The printed pattern circuits 2a to 2d of the electronic circuit unit 1
On the substrate 3 of 2c, heat-generating electronic components (for example, FETs)
Semiconductor device 4) may be attached.

There is no problem if the heat-generating electronic component 4 generates a small amount of heat, but if the heat generation amount is large, it adversely affects peripheral electronic components and the like.

For this reason, conventionally, a U-shaped heat radiating plate 5 as a separate component is mounted on the substrate 3, and a heat-generating electronic component 4 is mounted on the heat radiating plate 5.
In the case of a semiconductor element such as ET, the drain terminal D is connected to the printed pattern circuit 2a, the source terminal S is connected to the printed pattern circuit 2b, and the gate terminal G is connected to the printed pattern circuit 2c.

[0005]

However, since the heat radiating plate 5 as a separate component is required, the cost of parts and assembling is increased, and a space for mounting the heat radiating plate 5 on the substrate 3 is required. Pattern circuit 2
The circuit designs of a to 2c are restricted.

Further, since the printed pattern circuits 2a to 2c of the substrate 3 are used for input and output of the electronic component 4, a large current cannot be passed, and the connection portions of the terminals D, S, and G are soldered. Since the current value is ensured by the additional buildup, there is a problem that the current value is not stable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides an electronic circuit unit capable of efficiently radiating heat generated by heat-generating electronic components by using a bus bar rationally. Is the subject.

[0008]

According to a first aspect of the present invention, there is provided an electronic circuit unit for mounting a heat-generating electronic component on a substrate of an electronic circuit, wherein a bus bar is disposed on the substrate. An electronic circuit, wherein the electronic component is attached to a predetermined surface of the bus bar such that a predetermined surface of the electronic component comes into contact with the bus bar, and heat generated by the electronic component is transferred to the bus bar face to face to radiate heat. The unit is provided.

With this configuration, by mounting the electronic component on the bus bar in a face-to-face manner, the heat generated by the electronic component is efficiently transmitted to the bus bar and quickly radiated from the bus bar.

Preferably, a heat radiating portion is provided near a predetermined surface of the bus bar.

With this configuration, the heat radiation efficiency of the bus bar is improved.

According to a third aspect of the present invention, when a predetermined terminal of the electronic component is formed on the predetermined surface of the electronic component and the predetermined surface of the electronic component is attached to the bus bar in a face-to-face manner, It can be configured that predetermined terminals of the electronic component are connected to the bus bar.

With this configuration, the number of printed pattern circuits for connecting predetermined terminals of the electronic component can be reduced, and the width of the printed pattern circuit for connecting other terminals can be increased accordingly.

According to a fourth aspect of the present invention, the bus bar can be arranged in contact with a printed pattern circuit formed on the substrate, and the circuit can be branched into the bus bar and the printed pattern circuit.

With this configuration, the circuit can be easily branched into the bus bar and the printed pattern circuit simply by arranging the bus bar in contact with the printed pattern circuit.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, an electric connection box 6 used for a wire harness for an automobile is composed of a rectangular box-shaped lower case 7 and an upper case 8, and covers the lower case 7 with the upper case 8. By locking the locking hole 8a of the upper case 8 with the locking claw 7a of
Both cases 7, 8 are locked.

In each of the cases 7, 8, an electronic circuit unit 10 for controlling electric components is incorporated together with various printed circuit boards 9,.

On the upper surface of the upper case 8, various connector fitting portions 8b,..., 8b, etc., for fitting and connecting connectors of a wire harness of electrical equipment are provided.

On the upper surface 11a of the substrate 11 of the electronic circuit unit 10, a bus bar 12 is arranged and printed pattern circuits 13b and 13c are formed.

As shown in detail in FIGS. 2A and 2B, a heat-generating electronic component, for example, a semiconductor device 14 such as an FET.
Although the source terminal S and the gate terminal G are the same as the conventional one, the drain terminal D is formed on the wide surface 14a of the square semiconductor element 14.

The semiconductor element 14 is connected to the bus bar 12 by bringing the wide surface 14a, which is the drain terminal D, into contact with the upper surface 12a of the bus bar 12 face-to-face and joining the two sides 14a, 12a with solder a. Attach.

The bus bar 12 is provided in the through hole 1 of the substrate 11.
1b, the downwardly bent portion 12b
Can be fixed to the substrate 11 by inserting the solder a into the gap between the bent portion 12b and the metal fitting 15 by utilizing the capillary phenomenon.

Further, the semiconductor element 14 is provided with each of the printed pattern circuits 13 b and 13 c and the through hole 11 of the substrate 11.
b, 11b, the terminals S, G are inserted from above into the fittings 15, 15, respectively, and the solder a is inserted into the gaps between the terminals S, G and the fittings 15, 15 by capillary action. Each printed pattern circuit 1
3b, 13c.

As shown in FIGS. 3A and 3B, the bent portion 12b of the bus bar 12 is inserted into the through hole 11b of the substrate 11, and the bent portion 12b is formed on both sides of the upper surface 11a and the lower surface 11c of the substrate 11. By soldering a to the substrate 1
It can be fixed to 1. Further, as shown in FIG. 3C, the clip portion 12d is attached to the bent portion 12b of the bus bar 12.
The clip portion 12d can be fixed to the substrate 11 by inserting the clip portion 12d into the through hole 11b of the substrate 11 and locking it.

As shown in FIG. 2A, near the upper surface 12a of the bus bar 12 to which the semiconductor element 14 is attached,
A wide and upwardly radiating heat radiating portion 12e is provided, and a large number of heat radiating holes 12f are formed in the heat radiating portion 12e.

As shown in FIG. 2 (C), the semiconductor element 14 has an extended portion 14g in which the wide surface 14a of the semiconductor element 14 is extended upward at the upwardly bent portion 12g of the bus bar 12.
b may be attached with a screw 16.

Further, the bus bar 12 has a structure shown in FIG.
4H, a fuse terminal 12i as shown in FIG. 4B, and a terminal 12 with strain relief for preventing solder cracks as shown in FIG. 4C.
j can be formed.

Further, the bus bar 12 includes
As shown in (D), a portion 12k that forms a circuit can be formed.

When the electronic circuit unit 10 is configured as described above, the heat generated by the semiconductor element 14 is generated in a face-to-face manner by attaching the wide surface 14a of the semiconductor element 14 to the upper surface 12a of the bus bar 12 in a face-to-face manner. The heat is transferred to the bus bar 12, and the heat is quickly released from the bus bar 12.

As a result, since the bus bar 12 can be used as a heat radiating component, a conventional heat radiating plate is not required, so that component costs and assembly costs are reduced.

Further, since a space for mounting a heat sink is not required, the degree of freedom in circuit design of the printed pattern circuits 13b and 13c is improved.

In particular, when the heat radiating portion 12e is provided near the mounting portion of the bus bar 12 to the semiconductor element 14, the heat radiating efficiency of the bus bar 12 is further improved.

Further, the drain terminal D of the semiconductor element 14
Are formed on the wide surface 14a, so that the semiconductor element 14
Since the number of the printed pattern circuits (corresponding to 2a in FIG. 8) for connecting the drain terminal D of this embodiment can be reduced, the printed pattern circuits 13b and 13c for connecting the source terminal S and the gate terminal G can be made wider by that amount. It is not necessary to build up the solder for securing the current value as described above, and the current value is stabilized.

Since the drain terminal D of the semiconductor element 14 can be directly connected to the bus bar 12, a large current can flow.

As shown in FIG. 5, when the lower surface 12c of the bus bar 12 is placed in contact with the printed pattern circuit 13 formed on the substrate 11, the bus bar 12 can be easily formed.
And the print pattern circuit 13 can be branched.

As shown in FIG. 6, the electronic circuit unit 10
The bus bars 12A and 12B are arranged on the upper surface 11a of the substrate 11 so as to face each other.
Semiconductor device 14 so as to extend over upper surfaces 12a, 12a of
Are brought into face-to-face contact.

The drain terminal D of the semiconductor element 14, for example, is connected to the printed pattern circuit 13 on the upper surface 11a of the substrate 11 (not specifically shown), and the source terminal S is provided.
And the gate terminal G are connected to the through holes 11b, 11m of the substrate 11 from the small holes 12m, 12m formed in the bus bars 12A, 12B.
b is fixed to the fittings 15, 15 from above, and solder a is inserted into the gaps between the terminals S, G and the small holes 12m, 12m and the gaps between the terminals S, G and the fittings 15, 15. Are poured by utilizing the capillary phenomenon, the terminals S and G can be easily fixed to the bus bars 12A and 12B.

As a result, each terminal S,
Since G can be directly connected to the bus bars 12A and 12B, a large current can flow.

As shown in FIG. 7, a bus bar 1 is placed on a printed pattern circuit 13 formed on the substrate 11.
If the lower surface 12c of the 2A is placed in contact with the circuit, the circuit can be easily branched to the bus bar 12A and the printed pattern circuit 13.

[0041]

As is clear from the above description, in the electronic circuit unit according to the first aspect of the present invention, heat generation of the electronic component can be efficiently performed by mounting the electronic component on the bus bar in a face-to-face manner. Since heat is transferred to the bus bar and heat is quickly radiated from the bus bar, the bus bar can be used as a heat radiating component. This eliminates the need for a space for mounting the printed circuit, thereby improving the degree of freedom in circuit design of the printed pattern circuit.

Further, since a bus bar can be used for input / output of electronic parts, a large current can flow.

When the heat radiating portion is provided in the bus bar, the heat radiating efficiency of the bus bar is improved.

According to a third aspect of the present invention, when the predetermined terminal of the electronic component is formed on a predetermined surface and the predetermined surface is attached to the bus bar face-to-face, the predetermined terminal of the electronic component is connected to the bus bar with one touch. As a result, the number of printed pattern circuits for connecting predetermined terminals of the electronic component can be reduced, and the width of the printed pattern circuit for connecting other terminals can be increased accordingly. It is not necessary to build up the solder to secure the current, and the current value becomes stable.

If the bus bar is arranged in contact with the printed pattern circuit on the board as in claim 4, the circuit can be easily branched into the bus bar and the printed pattern circuit.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an electric junction box incorporating an electronic circuit unit of the present invention.

2A is a perspective view of a main part of a bus bar to which a semiconductor element is mounted, FIG. 2B is a cross-sectional view of FIG. 2A, and FIG. 2C is a perspective view of a main part of a bus bar to which a semiconductor element is mounted with screws. .

FIG. 3A is a perspective view of a bus bar fixing structure,
(B) is a sectional view fixed with solder, and (C) is a sectional view fixed with a clip.

4A, 4B, and 4C are perspective views of terminals formed on a bus bar, and FIG. 4D is a perspective view of circuit components formed on the bus bar.

FIG. 5 is a perspective view in which the bus bar of FIG. 1 is arranged in contact with a printed pattern circuit.

FIG. 6A is a perspective view of a main part of a modified example of a bus bar to which a semiconductor element is attached, and FIG. 6B is a cross-sectional view of the main part of FIG.

FIG. 7 is a perspective view in which the bus bar of FIG. 6 is arranged in contact with a printed pattern circuit.

FIG. 8 is a perspective view of a conventional electronic circuit unit.

[Explanation of symbols]

 Reference Signs List 6 Electrical connection box 10 Electronic circuit unit 11 Substrate 12 Bus bar 12a Upper surface (predetermined surface) 12e Radiator 13 (b, c) Printed pattern circuit 14 Semiconductor element 14a Wide surface (predetermined surface) D Drain terminal

Continued on the front page (72) Inventor Takahiro Onizuka 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi Harness Research Institute, Ltd.

Claims (4)

[Claims] 1. An electronic circuit unit for mounting a heat-generating electronic component on a substrate of an electronic circuit, wherein a bus bar is arranged on the substrate, and a predetermined surface of the electronic component contacts a predetermined surface of the bus bar face-to-face. An electronic circuit unit wherein the heat generated by the electronic component is transferred to the bus bar face-to-face to dissipate heat. 2. The electronic circuit unit according to claim 1, wherein a heat radiator is provided near a predetermined surface of the bus bar. 3. A predetermined terminal of the electronic component when a predetermined terminal of the electronic component is formed on the predetermined surface of the electronic component and the predetermined surface of the electronic component is attached to the bus bar in a face-to-face manner. The electronic circuit unit according to claim 1, wherein the electronic circuit unit is connected to a bus bar. 4. The bus bar according to claim 1, wherein the bus bar is arranged in contact with a printed pattern circuit formed on the substrate, and the circuit is branched into the bus bar and the printed pattern circuit. An electronic circuit unit as described.