JPH1075571A - Hybrid integrated circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent switching noise from flowing out. SOLUTION: The emitter potential of a switching transistor Q0 constituting an active filter is always stabilized at the ground potential during the positive and negative half periods of the potential at the connecting point of diodes D1 and D3 with commercial alternating current by connecting one end of a reactor L to the positive DC output terminal of a bridge rectifier circuit constituting the active filter and composed of diodes D1 -D4 and the collector and emitter of the transistor Q0 between the other end of the reactor L and a ground. Therefore, switching noise can be prevented from flowing out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid integrated circuit device in which a power active filter is mounted on an insulated metal substrate, and more particularly, to suppress a leakage current from the insulated metal substrate to an external structure based on a switching operation. Active·
The present invention relates to a hybrid integrated circuit device equipped with a filter.

[0002]

2. Description of the Related Art In recent years, active filters have attracted attention in terms of measures against rectified power supply noise. A general active filter will be described with reference to FIG. The active filter is a bridge rectifier composed of diodes D _{1 to} D ₄ , an AC input terminal of the bridge rectifier and a voltage V
a reactor L connected between a commercial AC power supply indicated by _ac ,
A transistor Q connected in parallel between a pair of DC output terminals of the bridge rectifier circuit, a capacitor C _d for smoothing the DC output of the bridge rectifier circuit, a damper connected between the DC output terminal of the bridge rectifier circuit and the smoothing capacitor C _d. circuit composed of a diode D _5. Note that a control circuit for outputting a control pulse φ having a frequency of 15 KHz or higher for controlling the operation of the transistor Q is omitted.

Next, the operation of the active filter will be described. In a half cycle in which the reactor L side of the commercial AC is positive, the transistor Q outputs a high-level control pulse φ.
During the ON period, a closed circuit is formed by the reactor L-diode D ₁ -transistor Q-diode D _{4 to} allow current to flow through the reactor L. In a half cycle in which the commercial AC reactor L side is negative, the transistor Q While on, diode D ₂ -transistor Q-diode D ₃
-A closed circuit is formed by the reactor L, and a current flows through the reactor L similarly. When the control pulse φ goes low and the transistor Q is turned off, the previous two closed circuits are opened, and a counter electromotive force is generated in the reactor L. Since this back electromotive force has the same phase as the commercial alternating current, a voltage obtained by adding the back electromotive force of the reactor L and the voltage of the commercial alternating current is input to the bridge rectifier circuit while the transistor Q is turned off,
The rectified output is charged in the smoothing capacitor C _d to forward bias the Danba diode D _5.

Conventionally, this active filter is constituted by discrete components, but the wiring between the discrete components becomes longer, and new switching noise is induced by the inductance component of the wiring. For this reason, it is necessary to house the active filter in a large shield structure, and it has not been possible to sufficiently meet the demand for a reduction in the size of the power supply device.

Accordingly, the present inventor has proposed a hybrid integrated circuit device in which this active filter is mounted on an insulating metal substrate in Japanese Patent Application No. 63-2580. Next, the hybrid integrated circuit device will be described with reference to FIG. That is, both surfaces of a metal substrate (40) of aluminum or the like are covered with an insulating oxide film (42) formed by anodizing, and an insulating resin film (46) of epoxy or the like is formed on one of the insulating oxide films (42). , A copper foil circuit pattern (48) is formed. The diodes D _{1 to} D ₄ and D ₅ , the transistor Q,
Further, an extremely small active filter is realized by surface-mounting circuit components constituting a control circuit in a chip shape. As apparent from FIG. 7, the ground pattern of the circuit pattern (48) is the insulating oxide film (42).
And a bonding wire with the metal substrate under the insulating oxide film (42) to remove the stray capacitance due to the insulating resin layer (46).
Connected at (54).

When such a hybrid integrated circuit device is incorporated in an electronic device, it is usual that the insulating oxide film (42) on the back surface of the metal substrate (40) is brought into contact with the chassis and mounted with a structure with good heat dissipation. is there. Therefore, in this structure, a stray capacitance _CP (see FIG. 8) having at least the insulating oxide film (42) as a dielectric is generated between the metal substrate (40) and the chassis of the electronic device over the entire surface of the metal substrate (40).

[0007]

However, in the above-mentioned hybrid integrated circuit device, the emitter potential of the transistor Q of the active filter fluctuates greatly at a high frequency, and flows out as noise to the chassis of the electronic device via the insulating metal substrate. The use of an insulated metal substrate has a particular problem.

The cause of this problem will be described with reference to FIGS. FIG. 8A shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the commercial AC reactor L side is positive. In the positive half cycle, a closed circuit is formed by the reactor L-diode D ₁ -transistor Q-diode D ₄ , and the reactor L is located at a position where the collector load of the transistor Q is obtained.

On the other hand, FIG. 8B shows an equivalent circuit of a hybrid integrated circuit device in a half cycle in which the reactor L side of commercial AC is negative. In the negative half cycle, a closed circuit is formed by the diode D ₂ -transistor Q-diode D ₃ -reactor L, and the reactor L becomes an emitter load of the transistor Q.

[0010] As obvious from the positive half-cycle changes as the collector potential of the (FIG. 8 (A)) the transistor Q is switched at the charging voltage and frequency of the inter-ground potential control pulses φ of the smoothing capacitor C _d I do. In addition,
The emitter potential is maintained at the ground potential. However, in the negative half cycle (FIG. 8B), the reactor L
Since the emitter load, the emitter potential is changed to switch from the charging voltage and frequency of the inter-ground potential control pulses φ of the smoothing capacitor C _d.

Since the ground pattern of the hybrid integrated circuit device and the aluminum substrate (40) are connected by the bonding wire (54), the potential of the aluminum substrate (40) is reduced by the smoothing capacitor C in the negative half cycle. It changes so as to switch between the charging voltage of _d and the ground potential at the frequency of the control pulse φ.

[0012] This flows out as a switching noise in the chassis of the electronic device via the stray capacitance C _p formed between the chassis of an electronic device an aluminum substrate (40).

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made through a rectifier circuit for rectifying an AC voltage and outputting a DC voltage, and a diode for extracting a charging voltage from the DC voltage of the rectifier circuit. A smoothing capacitor for obtaining a DC voltage, a switching element that contacts the anode side of the diode and, when turned on, flows a current from the current outflow side to a ground line connected to the rectifier circuit, and a switching element that is turned off. In an active filter circuit having a reactor for applying a back electromotive force to the voltage on the anode side of the diode, a ground pattern corresponding to the ground line is mounted on an insulated metal substrate,
The reactor is connected between the output side of the rectifier circuit that outputs the DC voltage and the current inflow side of the switching element, thereby realizing a hybrid integrated circuit device in which the conventional problems are greatly improved. is there.

[0014]

Embodiments of the present invention will be described below. FIG. 1 shows a circuit configuration of a characteristic active filter employed in the present invention. This active filter includes diodes D _{1 to} D ₄ as shown in FIG.
A bridge rectifier circuit, a reactor L having one end connected to a positive DC output terminal of the bridge rectifier circuit which is a feature of the present invention, a collector between the other end of the reactor L and ground,
Transistor Q _o whose emitters are connected, damper diode D ₅ having an anode connected to the collector of the transistor Q _o, a smoothing capacitor C _d connected between the cathode and the ground of the damper diode D ₅
And a control circuit COM which supplies a control pulse φ to the base of the transistor Q _o.

The main circuit of the control circuit COM is constituted by a microcomputer and outputs a control pulse φ having a frequency of 15 KHz or more. Further, although not shown, the frequency of the control circuit COM control pulses φ detects the magnitude of the load current, or perform feedback control by duty, further measures the emitter current of the substrate temperature and the transistor Q _o Control to prevent the active filter from running away thermally. Although a microcomputer is used for the control circuit COM of the present embodiment, it is needless to say that predetermined control can be performed by a well-known circuit configuration such as a comparator and an operational amplifier.

[0016] The transistor Q _o is not intended to be limited to the transistor of Baibora structure shown in the figure, power MO
It can be changed to another element capable of high-speed operation, such as an S transistor, SIT, or IGBT. In addition, the rectifier circuit is not limited to the illustrated bridge rectifier circuit, and any well-known rectifier circuit can be used.

Next, the operation of the active filter configured as described above will be described with reference to FIG. In the half period of the connection point potential of the diode D ₁ and D ₃ of the commercial AC it is positive, and the transistor Q _o is turned on when the control pulse φ is at a high level of frequencies above 15KHz output from the control circuit COM, diode D ₁ - reactor L- transistor Q _o -
The closed circuit of the diode D ₄ is formed a current i _L flows through the reactor L and. Then, when the control pulse φ is at a low level, the transistor _Qo is turned off and the previous closed circuit is opened, and the reactor L generates a back electromotive force in an attempt to maintain the previous electrical state. The counter electromotive force and the bridge rectifier circuit voltage output and is added to the reactor L exceeded the charging voltage of the smoothing capacitor C _d in a long period as compared to the rectifier circuit of a capacitor input type, via a damper diode D ₅ The smoothing capacitor _Cd is charged.

In a half cycle in which the potential of the connection point between the commercial AC diodes D ₁ and D ₃ is negative, when the control pulse φ is at a high level, the transistor _Qo is turned on and the diode D 0 is turned on.
A closed circuit of ₂ -reactor L-transistor Q ₀ -diode D ₃ is formed, and current i _L flows through reactor L. Then, when the control pulse φ becomes low level and the transistor _Qo is turned off and the previous closed circuit is opened, back electromotive force is generated in the reactor L as before, and the back electromotive force and the output of the bridge rectifier circuit are output. Is added to the smoothing capacitor C _d
Is charged.

This will be described in more detail with reference to FIGS. 3 (A) is an equivalent circuit of the hybrid integrated circuit device in a half cycle of the connection point potential of the diode D ₁ and the diode D ₃ of the commercial AC is positive. In this positive half cycle, a closed circuit is formed by diode D ₁ -reactor L-transistor Q _o -diode D ₄ , and reactor L is at a position where the collector load of transistor Q _o is present.

On the other hand, FIG. 3B shows an equivalent circuit of a hybrid integrated circuit device in a half cycle in which the potential at the connection point between the commercial AC diodes D ₁ and D ₃ is negative. In the negative half cycle, the diode D ₂ - reactor L- transistor Q _o - closed circuit is formed by the diode D _3, the reactor L is similar to the positive half cycle a collector load of the transistor Q _o.

[0021] Therefore, according to the circuit configuration of the active filter, in the positive half cycle of the commercial AC, it is always the reactor L is inserted into the collector of the transistor Q _o in the negative half cycle, transistor Q _o The emitter potential is always stabilized at the ground potential.

[0022] Referring to FIG. 4, the active filter as described above, with the exception of the reactor L and a smoothing capacitor C _d, illustrating a specific structure of the embodiment mounted on the insulated metal substrate.

The circuit pattern with diagonal lines is grounded.
The circuit board is divided into two parts by a part of the ground pattern into a small signal circuit block corresponding to a blank portion in a substantially upper half of the drawing and a large current circuit block corresponding to a lower half of the drawing. Control pulse φ wiring or transistors Q _o of the emitter potential of the wiring is the ground pattern supplied from the large-current circuit block to the small signal circuit block to be supplied to the high-current circuit block from the small signal circuit block in the present embodiment are formed so as to bypass a part of, is not limited thereto, for example, the wiring of the emitter potential of the transistor Q _o connected by bonding wires to a predetermined position of the small signal circuit block (jumping wire Connection).

Furthermore, the ground pattern frequency, is connected to an aluminum substrate with a bonding wire W at a position closest to the emitter of the transistor Q _o a large current flows, and the aluminum substrate potential to the ground pattern potential and equipotential I have.

The high-current circuit block, the diode D ₁ to D ₄ constituting the bridge rectifier circuit, a damper diode D _5, the transistor Q _o is surface-mounted through a heat sink, further limiting the emitter current of the transistor Q _o Further, an emitter resistor R for measuring the value is formed. These elements are arranged so that current does not flow through the ground pattern section dividing the small signal circuit block and the large current circuit block. The external lead terminals connecting the large current circuit block and the external circuit and the external lead terminals of the small signal circuit block are arranged on opposing peripheral edges of the circuit board so that mutual coupling is reduced.

The externally connected smoothing capacitor C _d
And the distance between the damper diode D _{5 and} the smoothing capacitor C _d
To increase the influence of the charge and discharge capacity, a damper diode D ₅ is arranged in proximity to the terminal indicated by V ⁺ 4. For the same reason, the terminal indicated by V ⁺ and the ground terminal GND are arranged adjacent to each other. The cross-sectional structure of the hybrid integrated circuit device shown in FIG. 4 is common to that of FIG.

The above-described hybrid integrated circuit device of the present invention is attached to the chassis of an electronic device with the back surface of the insulating metal substrate in contact with the chassis of the electronic device in consideration of heat dissipation. Thus it is between the metal substrate and the chassis of the insulating metallic board in a structure in which the stray capacitance C _p is interposed as shown in FIG. However, since the metal substrate is connected to the ground pattern (hatched portion in FIG. 4) by the bonding wire W, the potential of the metal substrate becomes the same as that of the ground pattern.

According to the invention, a ground pattern, that is, the emitter potential of the transistor Q _o is stable at the ground potential as described above, switching a negative half cycle of the commercial AC through the stray capacitance C _p -Eliminates the possibility that noise will flow to the chassis.

FIG. 5 shows a circuit of a modification of the embodiment. The control circuit COM of the above embodiment has a function of outputting a multi-phase pulse for controlling the inverter circuit, and externally outputs the multi-phase pulse from the hybrid integrated circuit device.
Such a hybrid integrated circuit device has the advantage that it can be constructed on a relatively small scale, but has the disadvantage that it requires a large number of terminals for externally outputting polyphase pulses.

On the other hand, a modified example is the transistors Q ₁ to Q ₁ .
Also mounted on a single circuit board inverter circuit of three-phase composed of Q _6, multi-phase pulse from the control circuit COM via a circuit pattern formed on the circuit board to the base of the transistor Q ₁ to Q ₆ Is entered. Thus, the number of terminals is reduced and noise is prevented from being mixed into wiring between the active filter and the inverter circuit.

[0031]

As described above, according to the hybrid integrated circuit device of the present invention, (1) since the potential of the emitter of the transistor of the active filter is at the ground potential at a high frequency, the metal substrate of the hybrid integrated circuit device There is no danger of switching noise leaking to the chassis of the electronic device, and a hybrid integrated circuit device equipped with an extremely small active filter can be realized.

(2) The large current circuit and the control circuit are connected to the ground
Since the control circuit is divided by the pattern, the control circuit is shielded from noise generated in the large current circuit.

(3) Since the wiring between the elements constituting the active filter is shortened by the hybrid integrated circuit device, noise due to wiring inductance is suppressed.

(4) Since an insulated metal substrate is used as the circuit board, a relatively large stray capacitance is formed between the wiring pattern and the metal substrate, so that high-frequency noise is immediately reduced in the vicinity of the place where the noise is generated. Can be.

(5) Since an insulated metal substrate is used as the circuit board, the heat radiation characteristics are good, and the active filter can be made compact.

(6) Since an insulated metal substrate is used as the circuit board, unnecessary radiation from the hybrid integrated circuit device to the outside can be suppressed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating an active filter used in the present invention.

FIG. 2 is an operation waveform diagram of an active filter.

FIGS. 3A and 3B are diagrams illustrating changes in the emitter potential of a transistor according to the present invention, and are equivalent circuit diagrams of each half cycle of a commercial alternating current.

FIG. 4 is a plan view of the embodiment.

FIG. 5 is a circuit diagram of a modification.

FIG. 6 is a circuit diagram of a conventional active filter.

FIG. 7 is a sectional view of a circuit board.

FIGS. 8A and 8B are diagrams illustrating a change in the emitter potential of a conventional transistor, and are equivalent circuit diagrams of each half cycle of a commercial alternating current.

[Explanation of symbols]

L reactor D ₁ ~ D ₅ diodes C _d smoothing capacitor Q _o transistor COM control circuit

Continued on the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical display location H03H 11/04

Claims (1)

[Claims] 1. A rectifier circuit for rectifying an AC voltage to output a DC voltage, a smoothing capacitor for obtaining a DC voltage via a diode for extracting a charging voltage from the DC voltage of the rectifier circuit, and an anode side of the diode. A switching element that flows a current from a current outflow side to a ground line connected to the rectifier circuit when turned on, and a reactor that applies a back electromotive force to a voltage on the anode side of the diode when the switching element is turned off. In the active filter circuit having, a ground pattern corresponding to the ground line is mounted on an insulated metal substrate, and the reactor is connected between an output side of a rectifier circuit that outputs the DC voltage and a current inflow side of the switching element. An active filter circuit, which is connected between the active filter circuits.