JP2001358283A - Current shunt and composite semiconductor device comprising it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly reliable current shunt having good heat dissipation properties, and a small composite semiconductor device in which wiring length is shortened using that current shunt. SOLUTION: A resistive metallic body 4 is sandwiched by current terminals 5A, 5B to constitute a current shunt 3. A pair of conductor patterns 9A, 9B for current and conductor patterns 11A, 11B for detecting voltage are provided continuously to each other on a wiring insulation board 1. The current terminal 5A is bonded to the conductor pattern 9A for current and between the conductor patterns 11A, 11B for detecting voltage by means of a bonding wire 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a current shunt for measuring a current flowing in an electric circuit and a composite semiconductor device using the current shunt.

[0002]

2. Description of the Related Art FIG. 2 shows an example of using a current shunt. In the figure, a power supply E and a load L are connected in series between a drain D and a source S of a field effect transistor (hereinafter, simply referred to as a transistor) Q, and a current shunt SH is connected to a source S side of the transistor Q. is there.

In the above circuit, when an ON signal is applied to the gate G of the transistor Q, the transistor Q is turned on and power is supplied to the load L by the drain current ID. The role of the current shunt SH in the above circuit is to detect the voltage VSH across the current shunt SH when the drain current ID flows and to monitor how much current is flowing through the transistor Q.

When a drain current ID exceeding a specified value flows for some reason in the circuit of FIG.
The signal input to the gate G of the transistor Q is controlled by the voltage VSH detected at step (1) to reduce the drain current ID, or to turn off the transistor Q to cut off the drain current ID, and to set the transistor Q or the load L To prevent current destruction.

Next, FIG. 3 shows an example of the structure of the current shunt SH used in the above circuit. Although the overall configuration of the composite semiconductor device is omitted in this figure, a plurality of semiconductor chips are mounted on a conductor pattern (not shown) of the wiring insulating substrate 1 in a predetermined package. The current shunt SH is mounted on the wiring insulating substrate 1 in the circuit configuration shown in FIG. 2, and FIG. 3 shows only the arrangement and the configuration of the current shunt SH.

In FIG. 1, a component mounting pattern 2 is formed on a wiring insulating substrate 1, and a current shunt 3 is fixed on the pattern 2 by soldering. The configuration of the current shunt 3 is such that a pair of current terminals 5A and 5B are provided on the upper surface of a resistance metal body 4 made of metal, and a pair of voltage detection terminals 6A and 6B are opposed to each other at a position separated from the current terminals 5A and 5B. Have been.

A metal layer 8 is provided on the lower surface of the resistance metal body 4 with an insulating layer 7 interposed therebetween. The current terminals 5A and 5B of the current shunt 3 and the pair of current conductor patterns 9A and 9B formed on the wiring insulating substrate 1 are bonded by bonding wires 10. Further, the voltage detection terminals 6A, 6B are connected to a pair of voltage detection conductor patterns 11A, 11B provided on the wiring insulating substrate 1.
And a bonding wire 10.

[0008]

Since the conventional current shunt and the composite semiconductor device using the same are configured as described above, there are the following problems to be solved. (1) Current terminal 5 arranged on the upper surface of current shunt 3
A, 5B and the voltage detection terminals 6A, 6B are arranged on both sides of the upper surface so as to face each other.
A, 5B to conductor patterns 9A, 9B, 11A, 11B
The connection to the bonding wire 10 is distributed to both sides. In other words, the pair of conductor patterns 9
Since A and 9B and the pair of conductor patterns 11A and 11B are not formed at positions adjacent to each other, the wiring length becomes long. In addition, the wiring direction is limited to one direction, and the degree of freedom in component layout design is lost. (2) an insulating layer 7 on the lower surface of the resistance metal body 4 of the current shunt 3
Intervening, the heat radiation of the resistance metal body 4 is deteriorated,
To prevent the temperature from rising, the surface area of the resistance metal body 4 must be increased accordingly. Therefore, the component mounting pattern 2 on which it is mounted also becomes large, and it is difficult to reduce the size of the composite semiconductor device. (3) The insulating layer 7 is deteriorated due to long-term use, and the reliability of the current shunt 3 is reduced.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a high degree of freedom in the direction of connection from the current terminals of a current shunt to a conductor pattern on a wiring insulating substrate.
It is another object of the present invention to provide a composite semiconductor device capable of shortening the wiring length and a highly reliable current shunt with excellent heat dissipation and no deterioration.

[0010]

According to the present invention, a resistance shunt is sandwiched between current terminals to form a current shunt, and a pair of current conductor patterns and a voltage are formed on a wiring insulating substrate so as to be adjacent to each other. A conductor pattern for detection is provided, and the current terminal and the conductor pattern for current, and between the voltage detection terminal and the conductor pattern for voltage detection are bonded by bonding wires. As a result, since the current shunt does not have the insulating layer interposed, the heat dissipation is improved, and the reliability is improved because there is no fear of deterioration. In addition, the connection direction is not limited to one direction, and a composite semiconductor device with increased design flexibility, reduced wiring length, and reduced size can be obtained.

[0011]

An embodiment of the present invention will be described below with reference to FIG. In the figure, the configuration of the entire composite semiconductor device is omitted. On the wiring insulating substrate 1 of the composite semiconductor device, a conductor pattern corresponding to a component mounted on the substrate 1 is provided.

That is, in the figure, the current conductor pattern 9 corresponding to one main surface serving as the lower surface of the current shunt 3 is shown.
B and a current conductor pattern 9A connected to the other main surface, which is the upper surface in the drawing of the current shunt 3, are provided adjacent to each other as shown. The conductor pattern 9B is provided so as to extend from the base conductor pattern 12 having a relatively large area.

On the wiring insulating substrate 1, a pair of voltage detecting conductor patterns 11A and 11B are provided adjacent to each other at positions substantially 90 degrees different from the current conductor patterns 9A and 9B. I have.

Next, the structure of the current shunt 3 will be described. The current shunt 3 connects the resistance metal body 4 to the current terminal 5
A and 5B have a sandwiched structure.
The resistance metal body 4 uses, for example, manganin. Manganin is known as Mn; 12-18%, Ni;
5-4%, Cu; a copper alloy having the balance of the composition. The electric resistivity is as high as about 42 × 10 6 Ωcm near room temperature.
In addition, the material has a very small temperature coefficient. Although manganin is used in the above embodiment, a metal material having a high specific resistance can be used instead of manganin.

A pair of current terminals 5A and 5B is formed by providing a layer made of, for example, copper on both main surfaces of the resistance metal body 4. The current shunt 3 having the above-described configuration is fixed on the core conductor pattern 12 by relatively high-temperature solder. Next, the current terminal 5A of the current shunt 3 and the current conductor pattern 9A
The bonding between the voltage detection conductor patterns 11A and 11B is performed by the bonding wire 10.

According to the above configuration, the pair of current conductor patterns 9A and 9B and the pair of voltage detection conductor patterns on the wiring insulating substrate 1 can be formed adjacent to each other. The wiring length can be reduced. Further, the wiring direction is not limited to one direction as in the related art, and the degree of freedom in design increases.

Furthermore, since the current shunt 3 does not have an insulating layer as in the prior art, heat dissipation is good, and the reliability is improved without fear of deterioration. Since there is no insulating layer,
The size of the device can be reduced.

The current terminal 5 on the upper side of the current shunt 3
A large-capacity current shunt 3 can be used by using a terminal made of a plate material between A and the current conductor pattern 9A as necessary.

[0019]

Since the present invention is constructed as described above, the degree of freedom in the connection direction from the current terminal of the current shunt to the conductor pattern on the wiring insulating substrate is increased, and the size of the compact composite is reduced. A semiconductor device is obtained, and excellent effects such as obtaining a highly reliable current shunt with excellent heat dissipation and no deterioration are obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a composite semiconductor device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram for explaining a current shunt built in the composite semiconductor device.

FIG. 3 is a perspective view showing a main part of a conventional composite semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wiring insulating board 3 Current shunt 4 Resistance metal body 5A, 5B Current terminal 9A, 9B Current conductor pattern 10 Bonding wire 11A, 11B Voltage detection conductor pattern 12 Base conductor pattern

Claims (2)

[Claims] 1. A current shunt in which a current flows through an electric resistor and a current or a voltage is detected by utilizing a voltage drop of the resistor, current terminals are provided on both main surfaces of a flat electric resistor. A current shunt characterized in that a current flows in the thickness direction of the electric resistor from the main surface to the other main surface. 2. A pair of voltage detection conductor patterns and a pair of current conductor patterns for flowing current are provided adjacent to each other on a wiring insulating substrate of the composite semiconductor device, and a current is supplied to one of the current conductor patterns. One main surface of the shunt is fixed, and the other main surface of the current shunt and the other of the current conductor patterns are connected by a conductor, and one of the voltage detection conductor patterns is one of the current shunts. A composite semiconductor device, wherein a main surface and the other main surface of the current shunt are connected to each other by a conductor, respectively.