JP2664523B2 - Hybrid integrated circuit device - Google Patents

Description

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 an external device from an insulated metal substrate caused by a switching operation. The present invention relates to a hybrid integrated circuit device that suppresses a leakage current to the semiconductor device and reduces output voltage fluctuation.

(B) Conventional technology 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.

Active filter bridge rectifier circuit composed of diodes D ₁ to D _4, a reactor L that is connected between the commercial AC power source represented by the AC input terminal and the voltage V _ac of the bridge rectifier circuit, the DC output of the pair of the bridge rectifier circuit The circuit is composed of a transistor Q connected in parallel between the terminals, a capacitor C _d for smoothing the DC output of the bridge rectifier circuit, and a damper diode D ₅ connected between the DC output terminal of the bridge rectifier circuit and the smoothing capacitor C _d. . Normally, the control circuit for outputting a control pulse φ of frequencies above 15KH _z for controlling the operation of the transistor Q is omitted.

 Next, the operation of the active filter will be described.

In the half cycle in which the reactor L side of the commercial AC is positive, while the transistor Q is turned on by the high-level control pulse φ, a closed circuit is formed by the reactor L-diode D ₁ -transistor Q-diode D ₄ to form the reactor L During the half cycle in which the reactor L side of the commercial AC is negative, a closed circuit is formed by the diode D ₂ -transistor Q-diode D ₃ -reactor L while the transistor Q is on, and the reactor L Current flows through
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. smoothing capacitor a damper diode D ₅ and a forward bias
_Charged to C _d .

Conventionally, this active filter is configured by discrete components. However, 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.

The present inventor has proposed a hybrid integrated circuit device in which this active filter is mounted on an insulating metal substrate, as disclosed in Japanese Patent Application No. 63-25 / 1988.
No. 80 proposed. This hybrid integrated circuit device will be described with reference to FIG.

That is, both surfaces of a metal substrate (40) made of aluminum or the like are covered with an insulating oxide film (42) formed by anodizing, and an insulating resin layer (4) made of epoxy or the like is formed on one of the insulating oxide films (42).
A circuit pattern (48) of copper foil is formed via 6).
The diodes D _{1 to} D ₄ are placed on this circuit pattern (48).
A very small active filter is realized by surface-mounting D and D ₅ , transistor Q, and circuit components constituting a control circuit in a chip shape. As is clear from FIG. 7, the ground pattern of the circuit pattern (48) is used to remove the stray capacitance due to the insulating oxide film (42) and the insulating resin layer (46). ) It is connected to the lower metal substrate by a bonding wire (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. Accordingly, in this structure, a stray capacitance _Cp (see FIG. 8) having at least the insulating oxide film (42) as a dielectric is formed between the metal substrate (40) and the chassis of the electronic device over the entire surface of the metal substrate (40).

(C) Problems to be Solved by the Invention However, the active filter shown in FIG. 5 does not transmit power to the load side when the transistor Q is on, and only when the transistor Q is off. because power is transmitted to the load side, has a problem that Ritsupuru current of the smoothing capacitor C _d increases with the generation of noise to the outside pulsating power transfer is viewed intermittently to the load side occurs increases.

In addition, the hybrid integrated circuit device on which the active filter is mounted uses an insulating metal substrate in which the emitter potential of the transistor Q fluctuates greatly at a high frequency and flows out as noise to the electronic equipment chassis via the insulating metal substrate. Has its own problems.

The cause of this problem will be described with reference to FIGS. 7 (A) and 7 (B).

FIG. 7A shows an equivalent circuit of a 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. 7B shows an equivalent circuit of a hybrid integrated circuit device in a half cycle in which the reactor L side of the commercial AC is negative. In the negative half cycle, the diode D ₂ - transistor Q- diode D ₃ - closed circuit is formed by the reactor L, the reactor L is emitter load of transistor Q.

As is obvious from, the positive half cycle (Figure 7 (A)), the control between the charging voltage of the collector potential smoothing capacitor D _d of the transistor Q and the ground potential pulse φ
It changes so that it may switch at the frequency of. Note that the emitter potential is maintained at the ground potential. However, in the negative half cycle (Figure 7 (B)), since the reactor L is emitter load of transistor Q, the switching between the charging voltage and the ground potential of the emitter potential smoothing capacitor C _d at the frequency of the control pulses φ To change.

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

(D) Means for Solving the Problems The present invention has been made in view of the above problems, and a plurality of unit circuits each including a reactor, a transistor, and a diode are arranged between an output terminal of a rectifier circuit and a smoothing capacitor. By mounting an active filter having a circuit configuration in which a reactor is intermittently grounded on an insulated metal substrate, it is possible to realize a hybrid integrated circuit device in which the conventional problems are greatly improved.

(E) Operation Since the active filter with the circuit configuration in which the reactor is connected to the DC output terminal of the rectifier circuit and the other end of the reactor is intermittently grounded by the switching element is made into a hybrid integrated circuit device, it can be used in any phase of commercial AC. Also, the reactor acts as a collector load for the transistor,
The application of the high frequency switching voltage to the pattern is eliminated. Accordingly, the application of the high-frequency switching voltage to the metal substrate connected to the ground pattern is also eliminated, and the outflow of the switching noise through the stray capacitance caused by the mounting structure of the hybrid integrated circuit device can be prevented.

In addition, since the active filter employs a circuit configuration in which a plurality of unit circuits each including a reactor, a transistor, and a diode are arranged between the output terminal of the rectifier circuit and the smoothing capacitor, the charge / discharge operation of each reactor can be performed independently. At any time, at least one of the plurality of reactors is charged from the rectifier circuit, and the smoothing capacitor is charged from at least one of the plurality of reactors. The sum of the currents flowing through the reactor reduces the level of harmonic noise.

(F) Embodiment FIG. 1 shows a circuit configuration of a characteristic active filter employed in the present invention.

The active filter, as shown in the figure, the diode D ₁ to D bridge rectifier circuit composed of _4, a plurality of reactors L ₁ ~L ₃ having one end connected to the positive DC output terminal of the bridge rectifier circuit, collector between the other end and ground of the reactor L ₁ ~L _3, emitter plurality of transistors Q ₁ to Q ₃ are respectively connected an anode connected to the respective collectors of the transistors Q ₁ to Q _3, a cathode common connection Damper diodes D _{5 to} D ₇ , and this damper diode D ₅
Not smoothing capacitor C _d and illustrated is connected to the cathode of the to D _7, but a control circuit COM which supplies a control pulse phi ₁ to [phi] ₃ to the respective bases of the transistors Q ₁ to Q _3.

Although the illustrated embodiment includes three sets of unit circuits each including a reactor, a transistor, and a damper diode, the number of the unit circuits may be two or any number of four or more.

The main circuit of the control circuit COM is configured by a microcomputer, and outputs a control pulse φ of frequencies above 15KH _z. Although not shown, the control circuit CO
M is the frequency of the control pulses φ detects the magnitude of the load current, or perform feedback control by the duty, more active filters can not run away thermally by measuring the emitter current of the substrate temperature and the transistor Q ₀ Such control is also performed. Note that the control circuit CO of the present embodiment is
Although a microcomputer was used for M, predetermined control can also be performed by a well-known circuit configuration such as a comparator and an operational amplifier.

Transistors Q ₁ to Q ₃ is not limited to a transistor of the bipolar configuration shown, it is possible to change the power MOS transistor, SIT, IGBT or the like, to the other element capable of high speed operation. In addition, the rectifier circuit is not limited to the illustrated bridge rectifier circuit, and any well-known rectifier circuit can be used.

Next, referring to FIG.
The operation of the filter will be described.

A plurality of transistors Q ₁ to Q ₁ control pulses φ are input to the respective bases of ₃ to [phi] ₃ is a pulse having a phase difference of 120 degrees from each other in the illustrated embodiment.

When the control pulse phi ₁ the transistor Q ₁ becomes high level to turn on, current i _L1 in reactor L ₁ flows through the bridge rectifier circuit output. Then, the control pulse phi ₁ the transistor Q ₁ becomes low level is turned off, the reactor L ₁ generates a counter electromotive force in an attempt to maintain the previous electrical state. Counter electromotive force of this reactor L ₁ is an output of the same polarity of the bridge rectifier circuit, the charging of the smoothing capacitor C _d is started by the voltage to which they are added.

At the timing of the control pulse phi ₁ becomes low level,
Said operating independently of the, by the control pulse phi ₂ and transistor Q ₂ is turned on, a current i _L2 to the reactor L ₂ is beginning to flow, shortly after completion of charging of the smoothing capacitor C _d by the reactor L _1, reactor charging the smoothing capacitor C _d by L ₂ is performed.

Similarly thereafter, the reactor L ₁ ~L _3, the unit circuit composed of the transistors Q ₁ to Q ₃ and the damper diode D ₅ to D ₆ are sequentially charging and discharging operation of the reactor L ₁ ~L _3.

In the active filter of the present invention that operates as described above, since the waveforms of the commercial AC current i _ac and the charging current i _cd of the smoothing capacitor are the sum of the currents flowing through the respective reactors L _{1 to} L ₃ , the commercial AC voltage waveform V _ac Very similar, the level of harmonic noise is reduced, and the ripple in the capacitor charging current and the high frequency noise generated thereby are reduced.

The operation will be further described with reference to FIGS.

Figure 3 (A) shows an equivalent circuit of the hybrid integrated circuit device in a half cycle of the connection point potential of the diode D ₁ and D ₂ of the commercial AC is positive. In this positive half cycle, the diode
A closed circuit is formed by D ₁ -reactor L-transistor Q ₀ -diode D ₄ , and the reactor L is located at a position to be a collector load of the transistor Q ₀ .

On the other hand, FIG. 3B shows a commercial AC diode D _1.
Connection point potential of D ₂ is an equivalent circuit of the hybrid integrated circuit device in a half cycle of the negative and. In the negative half cycle, diode D ₂ -reactor L-transistor Q ₀ -diode
Closed circuit is formed by D _3, the reactor L is similar to the positive half cycle a collector load of transistor Q _0.

Therefore, according to the circuit configuration of the active filter, in the positive half cycle of the commercial AC, is always the reactor L is inserted into the collector of the transistor Q ₀ in the negative half cycle, the emitter potential of the transistor Q ₀ is Always stable to ground potential.

Referring to FIG. 4, the active filter described above is
Except for the reactor L and a smoothing capacitor C _d, illustrating a specific structure of the embodiment mounted on the insulated metal substrate. FIG. 1 shows an example in which two unit circuits each including a reactor, a transistor, and a damper diode are juxtaposed.

The hatched circuit pattern is a ground pattern, and the circuit board is formed by a part of the ground pattern, and the small signal circuit block corresponding to a blank portion in substantially the upper half of the drawing and the large circuit corresponding to the lower half of the drawing. It is divided into two current circuit blocks. In this embodiment, the wiring of the control pulses φ ₁ and φ ₂ supplied from the small signal circuit block to the large current circuit block, or the emitter potential of the transistors Q ₁ and Q ₂ supplied from the large current circuit block to the small signal circuit block Are formed so as to bypass a part of the ground pattern. However, the present invention is not limited to this, and jumping wires may be connected.

Further, this ground pattern is connected to the aluminum substrate by a bonding wire W at a position near one of the emitters of the transistors Q ₁ and Q ₂ through which a high frequency and large current flows, so that the potential of the aluminum substrate is equal to the potential of the ground pattern. I have to.

The large-current circuit block, the diode D ₁ to D ₄ constituting the bridge rectifier circuit, damper diodes D _5, D _6, transistors Q _1, Q ₂ is surface-mounted through a heat sink,
Further, emitter resistors R ₁ and R ₂ for limiting the emitter currents of the transistors Q ₁ and Q ₂ and measuring the values are formed. These elements are respectively arranged so that a large current does not flow in 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 block are arranged on the opposite peripheral edges of the circuit board so that mutual coupling is reduced.

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 the 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. The stray capacitance C _p are between the metal substrate and the chassis of the insulated metal substrate to have a structure interposed as shown in Figure 3. 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 the potential of the ground pattern.
According to the present invention, a ground pattern, that is, the emitter potential of the transistor Q ₀ is stable at the ground potential as described above, the negative switching noise in a half cycle of the commercial AC through the stray capacitance C _p is There is no danger of spillage into the chassis.

(G) Effects of the Invention 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 risk of switching noise leaking from the electronic device to the chassis of the electronic device, and a hybrid integrated circuit device mounted with an extremely small active filter can be realized.

(2) Since a plurality of unit circuits each including a reactor, a transistor, and a diode are arranged in parallel between the output terminal of the rectifier circuit and the smoothing capacitor as an active filter, the AC input current and the charging current of the smoothing capacitor are plural. The sum of the currents flowing through the reactor reduces the level of harmonic noise.

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

(4) Since the wiring between the elements constituting the active filter is shortened by adopting the hybrid integrated circuit device, noise caused by the wiring inductance is suppressed.

(5) 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 harmonic noise can be rapidly attenuated immediately near the place where the noise is generated.

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

(7) Since the 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 the active filter, and FIGS. 3A and 3B illustrate changes in the emitter potential of the transistor of the present invention. FIG. 4 is an equivalent circuit diagram of each half cycle of commercial AC, FIG. 4 is a plan view of the embodiment,
FIG. 5 is a circuit diagram of a conventional active filter, FIG. 6 is a sectional view of a circuit board, and FIGS. 7A and 7B are diagrams for explaining a change in the emitter potential of a conventional transistor.
It is an equivalent circuit diagram of each half cycle of a commercial alternating current. L ₁ ~L ₃ ...... reactor, D ₁ ~D ₇ ...... diode, C _d ...... smoothing capacitor, Q ₁ ~Q ₃ ...... transistor.

Claims (1)

(57) [Claims] 1. A rectifier circuit constituting an active filter, a plurality of switching elements, a plurality of diodes each having one end connected to the plurality of switching elements and the other end commonly connected, on a circuit pattern of an insulating metal substrate. A plurality of reactors are respectively connected between a DC output terminal of a rectifier circuit and each switching element, a charging capacitor is connected to a common connection terminal of the diode, and the circuit pattern is further provided. And a connecting portion for connecting the ground pattern to the metal substrate.