JP2003031979A - Control unit and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heat dissipation efficiency of a control unit, and to realize easy manufacturing of the unit. SOLUTION: The device body of a plurality of semiconductor devices 14 is secured to a rear of a heat dissipation member 16 constituting a control unit, and a terminal leg 14a of each semiconductor device 14 is made to project from the rear to a direction almost perpendicular to it and disposed being substantially flush. The terminal legs 14a can be mounted simultaneously on a common circuit substrate 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control unit equipped with a circuit board on which a plurality of semiconductor devices are mounted and mounted in an automobile or the like, and a technique for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, semiconductor devices such as FETs have been widely used as devices mounted on a circuit board of a control unit. While such a semiconductor device is small and has excellent functions, it generates a relatively large amount of heat.
The heat dissipation becomes an important issue.

Conventionally, as a control unit using such a semiconductor device, for example, JP-A-11-21
In Japanese Patent No. 4875, a plurality of semiconductor devices (IP in the same publication) are mounted on a common mounting block protruding from the inner surface of the housing.
While fixing S), a screw for fastening a metal bracket to the housing is screwed into the inside of the mounting block, and heat generated by each semiconductor device is used as a medium through the mounting block and the screw. It is disclosed that it is transmitted to a bracket.

[0004]

In the structure disclosed in the above publication, a mounting block protruding from the rear surface of the housing is interposed between each semiconductor device and the screw, and the thickness of the mounting block is relatively large. Since it is large, it is difficult to expect high heat dissipation performance (ie, semiconductor device cooling performance).

Further, the structure is such that the terminal legs of each semiconductor device fixed to the mounting block face the corners of the bottom surface of the housing, and the terminal legs of each semiconductor device are mounted on the circuit board. Since the semiconductor device is assembled in a procedure of fixing the semiconductor device to the mounting block after mounting, the assembling work is troublesome, and a large stress may occur in a soldering portion between each terminal leg and the circuit board. There is.

That is, since the mounting block and each semiconductor device always have a dimensional error in manufacturing, the relative position between the mounting block and each semiconductor device is deviated by an amount corresponding to the dimensional error, and such a deviation is caused. Nevertheless, by fixing the semiconductor device to the mounting block, the terminal leg of the semiconductor device is deformed, and stress is generated in the soldering part connecting the terminal leg and the circuit board. As a result, a crack may occur between the solder and the terminal leg portion or the circuit board to cause an electrical failure.

In view of such circumstances, the present invention enhances the heat radiation performance of the control unit without adversely affecting the mounting state of the semiconductor device on the circuit board, and
The purpose is to facilitate the manufacture of the unit.

[0008]

As means for solving the above problems, the present invention provides a plurality of semiconductor devices used in a control unit and a heat dissipation member provided so as to be exposed on the outer surface of the control unit. An integrated semiconductor device set for a control unit, wherein each semiconductor device has a plurality of terminal legs mounted on a circuit board, and these terminal legs project in the same direction from the device body. By fixing the device body of the semiconductor device to the back surface of the heat dissipation member, the terminal legs of each semiconductor device project in the same direction from the back surface of the heat dissipation member and are substantially parallel to the back surface of the heat dissipation member. The ones lined up above.

If this semiconductor device set is used, it includes the steps of manufacturing the semiconductor device set, mounting each terminal leg of the semiconductor device on a common circuit board, and covering the circuit board with a cover. The method allows the control unit to be manufactured. In this manufacturing method, each semiconductor device can be mounted on a common circuit board at the same time while fixing each semiconductor device to the heat dissipation member in advance. Is significantly increased. In addition, unlike the conventional method of mounting the semiconductor device on the circuit board and then fixing the device to the housing,
It is also possible to prevent stress from being generated at the connection portion between the semiconductor device and the circuit board.

In the control unit manufactured in this manner, that is, in the control unit in which the terminal legs of the semiconductor devices of the semiconductor device set are mounted on a common circuit board and the circuit board is covered with a cover. Since the device body of each semiconductor device is directly fixed to the heat dissipation member, its heat dissipation performance (semiconductor device cooling performance) is very high.

Further, in this control unit, the main body of each semiconductor device is mounted on the circuit board by mounting the terminal leg of each semiconductor device at a relative position where the main body of each semiconductor device and the circuit board are separated from each other. It is possible to have a configuration in which the terminal legs of the semiconductor device are mounted on the circuit board in a state of being separated from the circuit board, and thereby the exposed area of the semiconductor device is increased and the heat dissipation is further improved, It is also possible to suppress the heat effect on the circuit board.

In order to align the terminal legs of the semiconductor devices, for example, a projecting portion may be formed on the back surface of the heat dissipation member, and the semiconductor devices may be fixed on the projecting portion. With this configuration, it is possible to control the position of the terminal leg of each semiconductor device by setting the height dimension of the protruding portion.

In the semiconductor device set, an insulating case molded integrally with the connector terminal is provided, and the heat dissipation is performed in the insulating case in a state where the connector terminal and the terminal leg of each semiconductor device are aligned on substantially the same plane. If the member is attached, the manufacturing efficiency of the entire control unit including the connector can be further increased. Specifically, a step of manufacturing the semiconductor device set, a step of mounting the terminal legs of the semiconductor devices of the semiconductor device set and the connector terminals of the insulating case on a common circuit board, and covering the circuit board with a cover. With the method including the step, it becomes possible to simultaneously mount the terminal legs of each semiconductor device and the connector terminals on the common circuit board.

In the above-described manufacturing method, it is possible to inject a potting agent into the inside of the cover through the hole by covering the circuit board with the cover by making a hole in the cover in advance. The waterproof property inside the control unit can be improved in various steps.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention.
~ It demonstrates based on FIG.

The control unit shown in FIGS. 1 to 4 includes an insulating case 10, a circuit board 12, a plurality of semiconductor devices (FETs in the illustrated example) 14, a heat radiating plate 16 and a cover 18.

The insulating case 10 is wholly molded integrally with an insulating material such as synthetic resin. This insulation case 1
An opening 10a into which the heat dissipation plate 16 is fitted is provided at the rear of the upper surface of 0, and the lower surface is open over almost the entire area.

At the front part of the insulating case 10, there is formed a connector housing portion 10c which opens forward, and the connector housing portion 10c is integrally molded with a plurality of connector terminals 20 as shown in FIG. Each connector terminal 20 has an L-shape with both ends facing forward and downward, an intermediate portion thereof is embedded in the insulating case 10, a front end portion thereof projects into the connector housing portion 10c, and a lower end portion thereof is formed. It projects downward from the insulating case 10.

The circuit board 12 is fitted into the lower surface opening of the insulating case 10 and fixed to the insulating case 10 with a screw 23. On the circuit board 12, the semiconductor devices 14 are mounted in addition to the plurality of circuit elements 22.

Each semiconductor device 14 has a block-shaped device body, and a plurality of (three in the illustrated example) terminal legs 14a project from the device body. These terminal legs 14a are bent halfway and all project in the same direction (downward in FIG. 1). Further, the device body is provided with a through hole 14b into which the fixing screw 24 can be inserted.

The heat radiating plate 16 is made of a material having excellent thermal conductivity such as aluminum or aluminum alloy, and has a plate shape fitted into the opening 10b of the insulating case 10. Fins 16a for increasing the surface area are formed on the outer surface side of the heat dissipation plate 16, and projecting portions 16c that project inwardly from other portions are formed at both end portions in the width direction on the back surface side. . And this protrusion 1
A screw hole 16b into which the screw 24 can be screwed is provided so as to penetrate 6c.

Like the insulating case 10, the cover 18 is made of an insulating material such as synthetic resin and has a container shape that opens upward. The side wall of the cover 18 is provided with a plurality of locking holes 18a, and the locking holes 18a are engaged with the locking protrusions 10d provided on the side wall of the insulating case 10 to insulate the cover 18 from the insulation. The shape of the cover 18 is set such that the cover 18 covers the circuit board 12 from the lower side while being connected and integrated with the case 10.

The bottom wall of the cover 18 is provided with a pair of through holes 18b, and the potting agent 26 can be injected into the cover 18 from one through hole 18b.

Next, a method of manufacturing the control unit will be described with reference to FIGS. At the stage of assembling this control unit, each step is carried out with the top and bottom reversed from the usage pattern shown in FIGS.

1) As shown in FIG. 5, the device bodies of the plurality of semiconductor devices 14 are connected to the protrusions 1 on the back surface of the heat sink 16.
6c, through holes 14b of each semiconductor device 14
Each semiconductor device 14 is fixed to the heat dissipation plate 16 by inserting a screw into the screw hole 16 b of the heat dissipation plate 16 and screwing it into. As a result, the terminal leg 14a of each semiconductor device 14
Protrudes in a direction substantially orthogonal to the back surface of the heat sink 16,
In addition, they are arranged on substantially the same plane.

2) The insulating case 10 as shown in FIG. 6, that is, the insulating case 10 integrally molded with the connector terminal 20 is manufactured.

3) The heat sink 16 is fitted and fixed in the opening 10b of the insulating case 10 (the semiconductor device set according to claim 2 of the present application is completed). At this time, as shown in FIG. 6, the height of the projecting portion 16c is set so that the terminal legs 14a and the connector terminals 20 of each semiconductor device 14 all project in the same direction and are aligned on substantially the same plane. The size is set.

4) As shown in FIG. 7, each of the terminal legs 14
a and the connector terminals 20 are inserted into the through holes provided in the circuit board 12, and the insertion portions are soldered together at a position where a gap d is secured between the device body of each semiconductor device 14 and the circuit board 12. To do. That is, the semiconductor devices 14 and the connector terminals 2 are provided on the circuit board 12 at relative positions such that the device bodies and the circuit board 12 are separated from each other.
Implement 0.

5) As shown in FIG. 8, the circuit board 12
The cover 18 is attached to the insulating case 10 so that the cover 18 is covered from above and the whole is integrated. And
From one through hole 18b of the cover 18 to the potting agent 2
6 is injected (the other through hole 18b is used for air bleeding) to seal the inside.

In the manufacturing method described above, the terminal legs 14a and the connector terminals 20 of each semiconductor device 14 can be inserted into the through holes of the common circuit board 12 at the same time, and the inserted portions are soldered together. be able to.
That is, the semiconductor devices 14 and the connector terminals 20 can be mounted on the circuit board 12 simultaneously and quickly, and the assembly efficiency of the control unit is dramatically improved.

According to the control unit manufactured by such a process, each semiconductor device 14 is directly fixed to the heat dissipation plate 16 side, and the device body is separated from the circuit board 12. The heat dissipation of the device is high, and the thermal effect on the circuit board 12 is small.

The second embodiment is shown in FIGS.

In the first embodiment, the insulating case 1 is used.
However, the control unit (FIGS. 9 to 11) according to the second embodiment includes the heat dissipation case 30 that also serves as the heat dissipation member and the main body case. The insulating case 10 is omitted. Further, the connector 32 is molded independently of the case, and the housing of the connector 32 is fixed on the circuit board 12 by the screw 33.

Projecting portions 30a projecting inward (that is, the rear surface is projecting) more than other portions are formed at both ends in the width direction at the rear portion of the heat dissipation case 30, and the projecting portions 30a are screwed. A hole 30b is provided. While a plurality of locking holes 30c are provided on the side wall of the heat dissipation case 30,
On the inner side surface of the side wall of the cover 18, a locking projection 1 protruding inwardly
8c is formed, and the locking projection 18c is formed in the locking hole 30.
By engaging with c, the heat dissipation case 30 and the cover 1
8 and 8 are integrally connected. An opening 30d for exposing the connector 32 to the outside is formed on the front side of the heat dissipation case 30.

The method of manufacturing this control unit is as follows. Incidentally, with respect to this control unit as well, at the assembly stage, each step is carried out with the top and bottom reversed from the normal use state shown in FIGS.

1) The connector 32 is mounted on the circuit board 12.

2) The device body of each semiconductor device 14 is placed on the back surface of the projecting portion 30a of the heat dissipation case 30, and the screw 24 is inserted into the through hole 14b and screwed into the screw hole 30b of the heat dissipation case 30. The main body is directly fixed to the protrusion 30a. As a result, as shown in FIG. 12, all the terminal legs 14a of the respective semiconductor devices 14 project upward and are arranged substantially on the same plane (completion of the semiconductor device set according to claim 1 of the present invention. ).

3) The terminal leg 14 of each semiconductor device is placed in the through hole of each circuit board 12 with the connector 32 facing downward.
Insert a from the bottom. At this time, as shown in FIG. 12, the projecting dimension of the projecting portion 30a is set so that the connector 32 is just accommodated in the heat dissipation case 30. Then, the inserted portions are soldered together.

4) As shown in FIG. 13, the circuit board 1
2 so that the cover 18 covers the cover 2 from above.
Is attached to the heat dissipation case 30, and the potting agent 26 is injected from one through hole 18 b of the cover 18 to seal the inside. At this time, if the through hole 12a shown in the figure is provided at an appropriate position on the circuit board 12 so that the potting agent can pass through the through hole 12a, the filling of the potting agent becomes smoother (see FIG. In FIG. 11, the potting agent is not shown for convenience).

Also in the manufacturing method described above, the terminal legs 14a of the respective semiconductor devices 14 can be inserted into the through holes of the common circuit board 12 at the same time, and the inserted portions can be soldered together. . That is, the semiconductor devices 14 can be mounted on the circuit board 12 simultaneously and quickly, and the assembly efficiency of the control unit can be dramatically improved.

According to the control unit manufactured by such a process, since each semiconductor device 14 is directly fixed to the heat sink 16 side and the device body is separated from the circuit board 12, each semiconductor device is The heat dissipation of the device is high, and the thermal effect on the circuit board 12 is small.

In each of the above embodiments, the device body of each semiconductor device 14 is connected to the heat dissipation plate 16 or the heat dissipation case 30.
However, a thin insulating sheet having excellent heat conductivity or an adhesive for fixing the device may be interposed between the device body and the heat dissipation member.
The point is that the heat conduction may be performed substantially directly from the device body to the heat dissipation member.

The semiconductor device according to the present invention is not limited to the FET shown in the figure, but can be widely applied to devices having a relatively large heat generation amount.

[0044]

As described above, according to the present invention, the device main bodies of a plurality of semiconductor devices are fixed to the back surface of the heat dissipation member forming the control unit, and the terminal legs of each semiconductor device are arranged in a direction substantially orthogonal to the back surface. Since these terminal legs can be mounted on a common circuit board at the same time by projecting them and arranging them on substantially the same plane, without adversely affecting the mounting state of the semiconductor device on the circuit board, This has the effects of increasing the heat dissipation of each semiconductor device and facilitating the manufacture of the control unit.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a control unit according to a first embodiment of the present invention.

FIG. 2 is a front view of the control unit.

FIG. 3 is a sectional view taken along line BB of FIG.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a cross-sectional front view showing a stage in which each semiconductor device is fixed on the back surface of the heat dissipation plate when the control unit is assembled.

FIG. 6 is a sectional front view showing a stage in which a heat dissipation plate is attached to an insulating case when the control unit is assembled.

FIG. 7 is a sectional front view showing a stage in which the terminal legs and connector terminals of each semiconductor device are mounted on a common circuit board during assembly of the control unit.

FIG. 8 is a cross-sectional front view showing a step of mounting a cover on an insulating case and filling a potting agent inside when assembling the control unit.

FIG. 9 is an exploded perspective view of a control unit according to a second embodiment of the present invention.

10 is a sectional side view of the control unit shown in FIG.

11 is a sectional front view of the control unit shown in FIG.

12 is a cross-sectional front view showing a stage in which each semiconductor device is fixed on the back surface of the heat sink and the terminal legs of the semiconductor device are mounted on a common circuit board when the control unit shown in FIG. 9 is assembled.

13 is a cross-sectional front view showing a step of mounting a cover on a heat dissipation case and filling a potting agent inside when assembling the control unit shown in FIG. 9. FIG.

[Explanation of symbols]

10 Insulation case 12 circuit board 14 Semiconductor devices 14a Terminal leg 16 Heat dissipation plate (heat dissipation member) 16c protrusion 18 cover 18b Through hole for potting agent injection 20 connector terminals 26 potting agents 30 Heat dissipation case (heat dissipation member) 30a protrusion

Continued front page    (72) Inventor Shigeki Yamane             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Takahiro Onizuka             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Takahiro Asou             Sumitomo Den 1-14 Nishi-Suehiro-cho, Yokkaichi-shi, Mie Prefecture             Sozo Co., Ltd. (72) Inventor Yoshitaka Sumita             Sumitomo Den 1-14 Nishi-Suehiro-cho, Yokkaichi-shi, Mie Prefecture             Sozo Co., Ltd. (72) Inventor Chung Nao             Sumitomo Den 1-14 Nishi-Suehiro-cho, Yokkaichi-shi, Mie Prefecture             Sozo Co., Ltd. F-term (reference) 5E322 AA01 AA02 AA04 AB01 FA04                 5F036 BB05 BC03

Claims (9)

[Claims] 1. A semiconductor device set for a control unit in which a plurality of semiconductor devices used for a control unit and a heat dissipation member provided so as to be exposed on the outer surface of the control unit are integrated, and each of the semiconductor devices. Has a plurality of terminal legs mounted on the circuit board, these terminal legs projecting in the same direction from the device body, and by fixing the device bodies of these semiconductor devices to the back surface of the heat dissipation member, A semiconductor device set for a control unit, wherein the terminal legs of each of the semiconductor devices project from the back surface of the heat dissipation member in the same direction and are arranged on a surface substantially parallel to the back surface. 2. The semiconductor device set according to claim 1, wherein a protrusion is formed on the back surface of the heat dissipation member, and each semiconductor device is fixed on the protrusion. Semiconductor device set. 3. The semiconductor device set according to claim 1, further comprising an insulating case integrally molded with the connector terminal, wherein the connector terminal and the terminal leg of each of the semiconductor devices are arranged substantially on the same plane. A semiconductor device set for a control unit, wherein the heat dissipation member is attached to the insulating case. 4. A semiconductor device set for a control unit according to claim 1, wherein each terminal leg of the semiconductor device is mounted on a common circuit board,
A control unit in which this circuit board is covered with a cover. 5. The control unit according to claim 4, wherein the terminal legs of the semiconductor devices are mounted on the circuit board in a state where the main body of each semiconductor device is separated from the circuit board. unit. 6. A step of manufacturing the semiconductor device set for a control unit according to claim 1, a step of mounting each terminal leg of the semiconductor device on a common circuit board, and a step of covering the circuit board with a cover. A method of manufacturing a control unit, comprising: 7. A step of manufacturing the semiconductor device set for a control unit according to claim 3, a step of mounting each terminal leg of the semiconductor device and a connector terminal of an insulating case on a common circuit board, and the circuit board. And a step of covering with a cover. 8. The method of manufacturing a control unit according to claim 6, wherein the terminal legs of each semiconductor device are mounted on the circuit board at a relative position where the main body of each semiconductor device and the circuit board are separated from each other. And a method for manufacturing a control unit. 9. The method for manufacturing a control unit according to claim 6, wherein a hole is formed in the cover, the circuit board is covered with the cover, and then the hole is formed inside the cover. A method for manufacturing a control unit, which comprises injecting a potting agent.