JPH06335118A - Power module - Google Patents

Abstract

PURPOSE:To facilitate a copper bus bar mounting operation to an output terminal of a power control power module and to improve vibration resistance. CONSTITUTION:A power module connects a C2E1 terminal (output terminal) to a load (not shown) via a copper bus bar 5 to control an operation of a load, and has a guide 12 provided integrally with a cover 11 near the C2E1 terminal. The guide 12 has a rectangular through hole so formed that longitudinal and lateral lengths of the rectangle are formed slightly larger than a thickness and a width of the bar 5. The bar 5 is connected to the C2E1 terminal through the guide 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power module for high power control.

[0002]

2. Description of the Related Art In the field of handling large electric power such as mechaelectronics and car electronics, the application of electronics technology is progressing, and it is common to make a power module for control such as general-purpose inverters and motors by combining transistors and thyristors. It has become to.

Such a power module handles a large amount of current and is dangerous when a load connected to the power module is short-circuited. Therefore, the power module is generally used while monitoring the current. In many cases. Then, the magnitude of the current flowing through the load is constantly measured, and the current value is fed back to the control circuit to control the current.

The attachment of the module and the current sensor will be described below with reference to FIG. In FIG. 5, a power module 1 for controlling a general-purpose inverter, a motor, etc. has a power semiconductor element (not shown) in a case 2. A cover 3 is attached to the top of the case 2. Further, a plurality of drive signal terminals 4 are provided in the vicinity of the end of the case 2, and a drive signal of the power semiconductor element is input from the external control circuit (not shown) via the drive signal terminal 4. Further, C1 terminals, E2 terminals, and C2E1 terminals, which are input / output terminals of the power semiconductor element, are provided on the cover 3.

C2 which is an output terminal of the power module 1
A copper bus bar 5 is fastened and connected to the E1 terminal by a bolt 9. Then, the copper bus bar 5 penetrates the current sensor 6 and is connected to a load (not shown). The current sensor 6 is fixed to a bracket (support metal fitting) 8 with a mounting screw 7.

The power module 1 having the above structure is supplied with power from the C1 terminal and the E2 terminal. And
An external control circuit (not shown) outputs the power semiconductor element of the power module 1 via the drive signal terminal 4, that is, C2.
The output of the E1 terminal is changed to control the current flowing to the load via the copper bus bar 5. Here, the current sensor 6
Always measures the current flowing to the load via the copper bus bar 5, and controls the operation of the load by feeding back the current value to the external control circuit.

[0007]

By the way, in the case of controlling the load while measuring the current flowing through the power module 1 as described above, in order to reduce the measurement error caused by magnetic flux leakage, the current It is desirable that the gap between the inner wall of the through hole of the sensor 6 and the copper bus bar 5 is narrow.

On the other hand, since a large current flows through the copper bus bar 5, the temperature becomes considerably high due to Joule heat or the like. However, the current sensor 6 is equipped with an electronic circuit for obtaining the value of the current flowing through the copper bus bar 5 from the output generated by the current flowing through the copper bus bar 5, and this electronic circuit is composed of an IC and a resistor having temperature dependence. It is configured. Therefore, when the copper bus bar 5 contacts the inner wall of the through hole of the current sensor 6, the temperature around the electronic circuit also rises due to heat conduction, and if the temperature exceeds the allowable range, accurate current value measurement cannot be performed. I will end up. Furthermore, in an extreme case, the current sensor 6 may be damaged.

Here, the copper bus bar 5 is attached to the C2E1 terminal by tightening the bolt 9 using the attachment holes provided in the C2E1 terminal and the copper bus bar 5. The copper bus bar 5 is tightened with this bolt. Torque is applied by. Since this torque acts in the direction of arrow A or A'with the connection position with the C2E1 terminal as the center of rotation, the copper bus bar 5 may rotate and come into contact with the inner wall side portion of the through hole of the current sensor 6. is there. If the copper bus bar 5 is fixed in contact with the inner wall of the through hole of the current sensor 6, as described above, the current sensor 6 cannot perform accurate current measurement or is damaged. Therefore, at that time, it is necessary to loosen the bolt 9 that fixes the copper bus bar 5 to the C2E1 terminal once, perform the alignment again, and then tighten the bolt 9. Such work is very complicated.

Although the copper bus bar 5 is connected to the load at the other end, the force in the direction of arrow A or A'caused by the tightening of the bolt 9 is an unnecessary force at the mounting position of the copper bus bar 5 to the load. As a result, the mechanical deterioration of that part is accelerated.

Furthermore, when the power module 1 is used in a vibrating environment, or when a force is applied to the copper bus bar 5 due to an external factor, the copper bus bar 5 is displaced and the current sensor 6 becomes inoperable. There is a risk of contacting the inner wall of the through hole and other members.

The present invention solves the above problems,
The conductor (copper bus bar) that supplies power from the output terminal of the power module for power control to the power module can be easily installed in the correct position, and it is possible to realize a power module with strong vibration resistance. To aim.

[0013]

The power module of the present invention has at least one output terminal for supplying electric power to the outside thereof, and is provided with a guide for regulating the position of a conductor connected to the output terminal.

When a sensor is used to detect a current flowing through the conductor, the guide regulates the position of the conductor so as to maintain a predetermined gap with the inner wall of the through hole of the sensor.

[0015]

In the power module of the present invention, since the guide for regulating the position of the conductor (copper bus bar) connecting the output terminal and the external load is provided, when the conductor is attached to the output terminal, The deviation from the desired position where the conductor should be fixed becomes less than a predetermined value due to the position regulation by the guide. Therefore, when the sensor is used to detect the current flowing through the conductor, the work of attaching the conductor to the power module can be easily performed without contacting the inner wall of the through hole of the sensor.

Not only when the power module is attached to the output terminal as described above, but also when the power module is used in an environment where it vibrates or when a mechanical force due to an external factor is applied to the conductor. However, since the positional displacement of the conductor is regulated by the guide, the conductor does not come into contact with the sensor and other members, and unnecessary torque is not applied to the mounting position of the conductor.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a power module according to an embodiment of the present invention, in which the same reference numerals as those in FIG. 5 denote the same parts.

In FIG. 1, a power module 10 for high power control has a power semiconductor element (described later) in a case 2. And the inside of case 2 is
In order to protect the power semiconductor device, it is filled with Si gel and epoxy resin. A cover 11 is attached to the top of the case 2. Further, a drive signal terminal 4 for inputting a drive signal of the power semiconductor element is provided in the vicinity of the end of the case 2, and C1 terminal, E2 terminal, and C2E which are input / output terminals of the power semiconductor element.
One terminal is provided on the top of the cover 11. These C
A large current flows through the I / O terminals 1, 1, 2, and C2E1 terminals, so copper bus bars are connected instead of wiring such as lead wires, but in FIG. 1 the C1 and E2 terminals are connected to make the drawing easier to see. The copper bus bar to be connected is not shown, and only the copper bus bar 5 to be connected to the C2E1 terminal is shown. When the copper bus bar 5 is attached to the C2E1 terminal, both are connected and tightened using the bolt 9 and the nut provided below the C2E1 terminal. (The same applies to the C1 and E2 terminals.) Unlike the cover 3 of the conventional power module 1, the cover 11 of the power module 10 of this embodiment is integrally formed with the guide portion 12 near the end thereof. This guide portion 12 has a rectangular through hole, and the rectangular
The lengths of the lateral sides are formed slightly larger than the thickness and width of the copper bus bar 5, respectively.

The current sensor 6 is fixed to a bracket (support metal fitting) 8 with a mounting screw 7, and the bracket 8 is fixed near the power module 10 so that the current sensor 6 is arranged at a predetermined position with respect to the C2E1 terminal. . The current sensor 6 has a through hole, and when a current flows through the measured electric wire passing through the through hole, an output determined by the magnitude of the current is obtained. The current sensor 6 further has an electronic circuit that calculates the value of the current flowing through the measured electric wire from the output, and feeds back the current value calculated by the electronic circuit to the external control circuit of the power semiconductor element.
In this embodiment, the electric wire to be measured is the copper bus bar 5.

Next, the power semiconductor element and each input / output terminal in the power module 10 will be described with reference to FIG. FIG. 2 is a main part circuit diagram of the power semiconductor element in the power module 10. Power semiconductor element is IGB
It consists of T1 and IGBT2, and the emitter of IGBT1 and the collector of IGBT2 are connected. And
The gates of the IGBTs 1 and 2 are G1 and G2, and are connected to the drive signal terminal 4, respectively. Also, IGB
The collector of T1 is connected to the C1 terminal, the emitter of IGBT2 is connected to the E2 terminal, and the contact between the emitter of IGBT1 and the collector of IGBT2 is connected to the C2E1 terminal. Further, the contact between the emitter of the IGBT1 and the collector of the IGBT2 is connected to the drive signal terminal 4 as the E1 terminal and the emitter of the IGBT2 is connected to the E2 terminal.

A general method of using this power semiconductor device is to apply a power supply voltage to the C1 terminal and ground the E2 terminal. Then, a load is connected to the C2E1 terminal, and an external control circuit (not shown) inputs a gate signal to G1 and G2 via the drive signal terminal 4 to control the operation of the load.

Returning to FIG. In the figure, copper bus bar 5
Connects between the C2E1 terminal and the load. Here, the load is, for example, a motor, and the power module 10 controls the rotation thereof.

Next, the operation of attaching the copper bus bar 5 to the C2E1 terminal will be described. First, power module 1
0 and the bracket 8 to which the current sensor 6 is attached are installed at predetermined positions. And copper bus bar 5
Through the through holes of the current sensor 6 and the guide portion 12 of the power module 10. Further, the mounting holes formed at the tip of the copper bus bar 5 and the mounting holes of the C2E1 terminals are aligned with each other to bring the copper bus bar 5 and the C2E1 terminals into pressure contact with each other, and a nut provided below the bolt 9 and the C2E1 terminal Tighten with.

At this time, torque is applied to the copper bus bar 5 by tightening the bolt 9, and the copper bus bar 5 tries to rotate in the direction A or A'about the mounting position to the C2E1 terminal, but at a slight rotation. Since the copper bus bar 5 contacts the inner wall of the guide portion 12, it does not rotate any more.

This is realized by forming the shape of the through hole of the guide portion 12 to be slightly larger than the cross-sectional shape of the copper bus bar 5, but the through hole of the guide portion 12 is formed by the current sensor 6. The vertical and horizontal sides are smaller than the through holes of. Therefore, even if torque is applied to the copper bus bar 5 by tightening the bolt 9,
The copper bus bar 5 does not contact the inner wall of the through hole of the current sensor 6, and the current sensor 6 can be operated at a normal temperature.

Here, the copper bus bar 5 may come into contact with the inner wall of the through hole of the guide portion 12, but the guide portion 12 is integrally formed with the cover 11 of the power module 10, and is insulative and heat resistant. Since it is made of an excellent material, the current flowing through the copper bus bar 5 does not leak, and the heat generated by the current does not adversely affect the power semiconductor elements in the power module 10.

As described above, in the power module 10 of this embodiment provided with the guide portion 12, the position of the copper bus bar 5 can be set only by fixing the copper bus bar 5 penetrating the guide portion 12 to the C2E1 terminal. Therefore, the copper bus bar 5 can be fixed while maintaining a predetermined gap from the inner wall of the through hole of the current sensor 6 without performing a complicated alignment work.

The copper bus bar 5 is the power module 1
0 is a conductor that connects between the load and the copper bus bar 5
C2E1 of the power module 10 after fixing the load to the load
In the case of the procedure of fixing to the terminal, the torque when bolting the copper bus bar 5 to the C2E1 terminal is not applied to the mounting position to the load. This is also because the guide portion 12 regulates the rotation of the copper bus bar 5.

By the way, considering the case where the power module 10 is used in a vibrating environment (for example, mounted in an automobile), the bolt 9 fixing the copper bus bar 5 loosens due to the influence of the vibration, and the copper bus bar is loosened. 5
May be displaced, but the guide portion 12 regulates such displacement. Therefore, copper bus bar 5
Does not contact the current sensor 6 or other members,
It can be said that it has excellent vibration resistance.

In the power module 10 of the above embodiment, the guide portion 12 is formed at a position close to the C2E1 terminal and on the opposite side of the drive signal input terminal 4, but this position is not limited. The position where the guide portion 12 is formed is the installation position of the power module 10, the current sensor 6 and the load, or the shape of the copper bus bar 5 (copper bus bar 5
Is not necessarily linear), and for example, as shown in FIG. 3, a guide portion 14 may be formed at a corner portion on the cover 13 of the power module 10 close to the C2E1 terminal.

Next, the shape of the guide portion will be described with reference to FIG. The shape of the guide portion 15 of FIG. 4A shows the guide portion 12 of FIG. 1 or the guide portion 14 of FIG. That is, this is a configuration in which a rectangular through hole is provided in a rectangular parallelepiped shape.

The guide portion 16 shown in FIG.
It is a U-shape with the upper portion of the guide portion 15 shown in (a) removed. The inner width of the guide portion 16 is formed to be slightly wider than the width of the copper bus bar 5.
Even with such a shape, the rotation of the copper bus bar 5 described with reference to FIG. 1 can be restricted.

The guide portion 17 shown in FIG. 4C is the same as that shown in FIG.
It has a shape in which protrusions 18 are provided on the upper and lower sides and on the left and right sides of the inner wall of the guide portion 15 shown in FIG. When an external force such as the torque described with reference to FIG. 1 is applied to the copper bus bar 5 when the copper bus bar 5 is passed through the guide portion 17, the copper bus bar 5 comes into contact with the protruding portion 18 and the position is displaced. Is regulated, but in this case, the copper bus bar 5
Since the contact between the guide portion 17 and the guide portion 17 is point contact, the heat dissipation is excellent.

4 (a) to 4 (c) show examples of the shape of the guide portion, the guide portion of the present invention is not limited to the above shape, and when the copper bus bar is fixed to the power module. Includes all that regulate the positional displacement of the copper bus bar.

The circuit configuration of the power module of the present invention is not limited to the circuit shown in FIG. 2, but handles a large current and supplies the input / output current to the load by using a copper bus bar. It is widely applicable to modules.

[0036]

As described above, according to the present invention,
Since the power control power module is provided with a guide part that regulates the position of the copper bus bar connected to the output terminal,
Even if a force to rotate the copper bus bar is applied due to the bolt tightening torque when installing the copper bus bar, the copper bus bar will be displaced very little, and for example, the alignment with the sensor that detects the current of the copper bus bar is unnecessary, and the installation work It will be easier. Further, even when the power module is used in a vibrating environment, displacement of the copper bus bar is restricted and vibration resistance is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a power module of the present invention, and is a view showing an example when used with a current sensor.

FIG. 2 is a main part circuit diagram of a power semiconductor device provided in the power module shown in FIG.

3 is a cross-sectional view showing an example in which guide portions of the power module of FIG. 1 are formed at different positions.

FIG. 4 is a diagram showing a configuration example of a guide portion of the power module of the present invention.

FIG. 5 is a perspective view of an example of a conventional power module.

[Explanation of symbols]

 5 Copper bus bar (conductor) 6 Current sensor 10 Power module 11 Cover 12 Guide part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Harada 2-chome, Toyota-cho, Kariya city, Aichi Prefecture Toyota Industries Corporation

Claims (2)

[Claims] 1. A power module having at least one output terminal for supplying electric power to the outside, wherein a guide for restricting a position of a conductor connected to the output terminal is provided. 2. The power according to claim 1, wherein the guide restricts the position of the conductor so as to maintain a predetermined gap with the inner wall of the through hole of the sensor that detects the current flowing through the conductor. module.