JP2003088097A - Semiconductor circuit, motor drive circuit and motor power steering unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor circuit requiring a small installation area and not requiring intersection of wires. SOLUTION: The semiconductor circuit comprises a pair of semiconductor elements Q3 and Q4 connected in series through one-side terminals thereof wherein different fixed potentials are applied to the other terminals thereof and one fixed potential is outputted from one terminal. The pair of semiconductor elements Q3 and Q4 are stacked through an electrode 31 for connecting the one-side terminals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pair of semiconductor elements connected in series by one terminal, and different fixed potentials are applied to the other terminals, respectively. The present invention relates to a semiconductor circuit configured to output the above, a motor drive circuit including the semiconductor circuit, and an electric power steering apparatus including the motor drive circuit.

[0002]

2. Description of the Related Art In a bridge circuit for rotating a DC motor in both forward and reverse directions, and in an inverter used for motor drive, lighting, etc., a plurality of pairs of semiconductor elements connected in series are used. There is. As shown in FIG. 1, this semiconductor element pair is, for example, one semiconductor element Q3.
The terminal on the side not commonly connected of is connected to the power source P,
The terminal of the other semiconductor element Q4, which is not commonly connected, is grounded. Accordingly, when the semiconductor elements Q3 / Q4 are on / off, the potential of the power source P is
When the semiconductor elements Q3 / Q4 are off / on, the ground potential is output from each common connection node.

[0003]

Since the pair of semiconductor elements described above are conventionally arranged side by side in a plane, the semiconductor circuit formed thereof has a large bottom area and a large space for installation. There is a problem that requires.
There is also a problem that the circuit has to be extended for connecting the electrodes.

The present invention has been made in view of the above-mentioned circumstances, and in the first to third inventions, a semiconductor circuit that requires a small area for installation and does not need to cross wires is provided. The purpose is to provide. It is an object of a fourth invention to provide a motor drive circuit including the semiconductor circuit according to any one of the first to third inventions. A fifth object of the present invention is to provide an electric power steering apparatus including the motor drive circuit according to the fourth invention.

[0005]

In a semiconductor circuit according to a first aspect of the present invention, a pair of semiconductor elements are connected in series by one terminal, and different fixed potentials are applied to the other terminals, respectively. In the semiconductor circuit configured to output any one of the fixed potentials from the above, the pair of semiconductor elements have a laminated structure in which electrodes for connecting the terminals on one side are sandwiched. To do.

In this semiconductor circuit, a pair of semiconductor elements are connected in series by each one terminal, different fixed potentials are applied to each other terminal, and one of the fixed potentials is output from one terminal. The pair of semiconductor elements has a laminated structure in which electrodes for connecting one of the terminals are sandwiched. This makes it possible to realize a semiconductor circuit that requires a small area for installation and does not require wires to cross each other.

A semiconductor circuit according to a second aspect of the present invention includes a plurality of pairs of the semiconductor elements and has an integrated structure.

Since this semiconductor circuit has a plurality of pairs of semiconductor elements and has an integrated structure, it is suitable for use in a bridge circuit and an inverter, the area required for installation is small, and it is necessary to cross wires. It is possible to realize a non-semiconductor circuit.

A semiconductor circuit according to a third aspect of the invention is characterized in that a heat radiator for radiating heat is connected to each of the other terminals via an insulating layer.

In this semiconductor circuit, since the radiator for radiating heat is connected to each of the other terminals through the insulating layer, the heat radiation performance is small despite the small area required for installation. In addition, it is possible to realize a semiconductor circuit which does not need to cross wires.

A motor drive circuit according to a fourth aspect of the present invention includes the semiconductor circuit according to any one of claims 1 to 3, and is configured to drive the motor by the potential output from the semiconductor circuit. And

In this motor drive circuit, the semiconductor circuit according to any one of claims 1 to 3 is provided, and since the motor is driven by the fixed potential output from the semiconductor circuit, the area required for installation is small. A motor drive circuit can be realized.

An electric power steering apparatus according to a fifth aspect of the present invention includes a motor that assists steering, and a motor drive circuit that drives the motor.

Since the electric power steering apparatus includes the motor for assisting steering and the motor drive circuit for driving the motor, the motor drive circuit requires a small area for installation. It is possible to realize an electric power steering device equipped with.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings showing the embodiments thereof. FIG. 1 is a block diagram showing a main configuration of an embodiment of a semiconductor circuit and a motor drive circuit according to the present invention. This motor drive circuit 1
Reference numeral 3 is a circuit for driving a brushless (DC) motor 24 mounted on an electric power steering device of a vehicle. The brushless motor 24 includes a stator 24a in which coils A, B and C are star- or delta-connected, and a coil A,
It is composed of a rotor (rotor) 24b which is rotated by a rotating magnetic field generated by B and C, and a rotor position detector (resolver) 14 which detects a rotational position of the rotor 24b.

In the motor drive circuit 13, the power supply voltage of the vehicle-mounted battery P is connected to the anode side terminal of the semiconductor circuit 8. The semiconductor circuit 8 includes transistors Q1 and Q2 (semiconductor elements) connected in series between an anode side terminal and a ground terminal, and diodes D1 and D2 connected in series in the opposite direction.
And a transistor Q3 connected in parallel and connected in series.
Q4 (semiconductor element) and diodes D3 and D4 connected in series in the opposite direction are connected in parallel, and transistors Q5 and Q6 (semiconductor element) are connected in series, and diodes D5 and D6 connected in series in the opposite direction. Are connected in parallel.

The other terminal U of the star-connected coil A is connected to the common connection node of the transistors Q1 and Q2 and the common connection node of the diodes D1 and D2, and the common connection node of the transistors Q3 and Q4. Diode D
The other terminal V of the star-connected coil B is connected to the common connection node of the transistors D3 and D4, and the transistors Q5 and Q5 are connected.
The common connection node of 6 and the common connection node of the diodes D5 and D6 are connected to the other terminal W of the star-connected coil C.
Are connected.

The rotational position of the rotor 24b detected by the rotor position detector 14 is notified to the gate control circuit 8a. The gate control circuit 8a receives a rotation direction command and a motor current command value (PW) from a microcomputer (not shown).
M value command) is given. The gate control circuit 8a, in accordance with the instruction of the rotation direction command and the rotation position of the rotor 24b,
The gates of the transistors Q1 to Q6 are turned on / off, and, for example, U-V, U-W, V-W, V-U, W-U, W-
Like V and U-V, the path of the current flowing through the stator 24a is switched to generate a rotating magnetic field.

The rotor 24b is a permanent magnet and rotates by receiving a rotational force from this rotating magnetic field. Gate control circuit 8a
In addition, according to the motor current command value, the transistor Q
PWM (Pulse Width Modulati) on / off of 1 to Q6
ON) control to increase / decrease the rotational torque of the brushless motor 24. The diodes D1 to D6 are freewheeling diodes, and are the transistors Q1 to Q6.
The regenerative current and noise generated by turning on / off of the .circle-solid. Are circulated to smooth the rotation of the brushless motor 24. The motor current detection circuit 17 detects and adds currents (U-phase current, V-phase current, W-phase current) flowing through the terminals U, V, W of the brushless motor 24 to a microcomputer (not shown) as a motor current signal. give.

FIG. 2 is a perspective view showing a structural example of a main part of the semiconductor circuit 8. It should be noted that some parts are omitted to clearly show the configuration. In the semiconductor circuit 8, the anode 29 constitutes the bottom surface of the lower portion thereof, and the semiconductor elements Q1, Q3, Q5 (however, Q1 is not shown) are respectively connected to the upper surface of the anode 29 and arranged in parallel. On each upper surface of the semiconductor elements Q1, Q3, Q5,
A U-phase electrode 30, a V-phase electrode 31, and a W-phase electrode (electrodes, but the W-phase electrode is not shown) are connected and provided.

Semiconductor elements Q2, Q4 and Q6 (however, Q2 and Q6 are not shown) are provided on the upper surfaces of the U-phase electrode 30, the V-phase electrode 31 and the W-phase electrode (however, the W-phase electrode is not shown). )
Are respectively connected and provided. Semiconductor element Q
A cathode 28 is connected to the respective upper surfaces of 2, Q4 and Q6 (however, Q2 and Q6 are not shown), and the cathode 28 constitutes the upper bottom surface of the semiconductor circuit 8. The anode 29 and the cathode 2
The vertical positional relationship of 8 may be reversed. Semiconductor element Q
1, Q3, Q5, Q2, Q4, and Q6 are respectively connected to respective one ends of aluminum wires 26, and the other ends of the aluminum wires 26 are respectively provided outside the anode 29 and the cathode 28. Each is connected to the gate electrode 27.

FIG. 3 is a side sectional view showing a structural example of the main part of the semiconductor circuit 8. The semiconductor circuit 8 is housed in a case 36, the bottom surface of the case 36 is made of an insulating layer 33, and a heat sink 32 is provided in close contact with the outer (lower) surface of the insulating layer 33. The cathode 28 is formed on the upper surface of the insulating layer 33.
However, a part thereof is exposed outside the case 36.

The semiconductor element Q4 is connected to the upper surface of the cathode 28 by the solder 35, and the upper surface of the semiconductor element Q4 is V.
The phase electrode 31 is connected by solder 35, and a part of the V-phase electrode 31 is exposed outside the case 36. The semiconductor element Q3 is connected to the upper surface of the V-phase electrode 31 by the solder 35, and the anode 29 is connected to the solder 3 on the upper surface of the semiconductor element Q3.
5, the anode 29 is partly exposed outside the case 36.

An insulating layer 33 is formed on the upper surface of the case 36 of the anode 29, and a heat sink 32 is provided in close contact with the outer (upper) surface of the insulating layer 33. Semiconductor element Q
The respective ends of the aluminum wires 26 are connected to the respective gates of Q3 and Q4, and the other ends of the aluminum wires 26 are connected to the respective gate electrodes 2 provided on the upper surface of the insulating layer 33 on the cathode 28 side.
7 are connected respectively. The void portion in the case 36 is filled with the insulating filler 34, and the semiconductor circuit 8
Is integrally molded as.

FIG. 4 is a block diagram showing a main configuration of an electric power steering apparatus according to an embodiment of the present invention. This electric power steering device includes a torque sensor 10 for detecting a torque applied to a steering shaft (not shown).
The torque detection signal detected and output by the vehicle is applied to the microcomputer 12 via the interface circuit 11, and the vehicle speed signal detected and output by the vehicle speed sensor 20 for detecting the vehicle speed is applied to the microcomputer 12 via the interface circuit 21. To be

A relay control signal output from the microcomputer 12 is input to the relay drive circuit 15, and the relay drive circuit 15 turns on or off the fail-safe relay contact 15a according to the relay control signal. Based on the torque detection signal, the vehicle speed signal, and the motor current signal described later, the microcomputer 12 determines the torque / memory in the memory 18.
A motor current command value (PWM value command) is created by referring to the current table 18a, and the created motor current command value is given to the motor drive circuit 13. The motor drive circuit 13 is applied with the power supply voltage of the vehicle-mounted battery P through the fail-safe relay contact 15a, and rotationally drives the brushless motor 24 which is a motor for steering assist based on the given motor current command value.

When the brushless motor 24 rotates, the rotor position detector 14 detects the rotor position, and the motor drive circuit 13 detects the rotor position signal based on the detected rotor position signal.
The brushless motor 24 is rotationally controlled. The motor current flowing through the brushless motor 24 is the motor current detection circuit 17
Is detected by the above, is given to the microcomputer 12 as a motor current signal, and is fed back to the above-mentioned motor current command value.

[0028]

According to the semiconductor circuit of the first aspect of the present invention, it is possible to realize a semiconductor circuit that requires a small area for installation and does not require wires to cross each other.

According to the semiconductor circuit of the second invention, it is possible to realize a semiconductor circuit which is suitably used for a bridge circuit and an inverter, requires a small area for installation, and does not need to cross wires. I can.

According to the semiconductor circuit of the third aspect of the present invention, it is possible to realize a semiconductor circuit which has good heat dissipation performance and does not require wires to intersect, although the area required for installation is small. .

According to the motor drive circuit of the fourth invention,
It is possible to realize a motor drive circuit that requires a small area for installation.

According to the electric power steering apparatus of the fifth aspect of the present invention, it is possible to realize an electric power steering apparatus including a motor drive circuit which requires a small area for installation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of an embodiment of a semiconductor circuit and a motor drive circuit according to the present invention.

FIG. 2 is a perspective view showing a configuration example of a main part of a semiconductor circuit according to the present invention.

FIG. 3 is a side sectional view showing a configuration example of a main part of a semiconductor circuit according to the present invention.

FIG. 4 is a block diagram showing a main configuration of an electric power steering device according to an embodiment of the present invention.

[Explanation of symbols]

8 semiconductor circuit 8a gate control circuit 10 torque sensor 12 microcomputer 13 motor drive circuit 17 motor current detection circuit 18a torque / current table 24 brushless motor (motor) 26 aluminum wire 27 gate electrode 28 cathode 29 anode 30 U-phase electrode (electrode) 31 V-phase electrode (electrode) 32 Heat sink (radiator) 34 Filler 36 Case P In-vehicle battery Q1, Q2, Q3, Q4, Q5, Q6 Transistor (semiconductor element)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Motoo Nakai             3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka               Koyo Seiko Co., Ltd. F-term (reference) 3D033 CA03 CA13 CA16 CA20 CA21                 5H740 BA11 BB05 BB09 JA21 PP01                       PP02 PP03 PP04 PP06 PP07

Claims (5)

[Claims] 1. A pair of semiconductor elements are connected in series by each one terminal, different fixed potentials are applied to each other terminal, and one of the fixed potentials is output from the one terminal. In a certain semiconductor circuit, the pair of semiconductor elements have a laminated structure in which electrodes for connecting the terminals of each one are sandwiched. 2. The semiconductor circuit according to claim 1, wherein a plurality of pairs of the semiconductor elements are provided to form an integrated structure. 3. The semiconductor circuit according to claim 1, wherein a heat radiator for radiating heat is connected to each of the other terminals via an insulating layer. 4. A motor drive circuit comprising the semiconductor circuit according to claim 1, wherein the motor is driven by a potential output from the semiconductor circuit. 5. An electric power steering apparatus comprising: a motor that assists steering; and the motor drive circuit according to claim 4, which drives the motor.