JPH0433362A - Hybrid integrated circuit device - Google Patents

Abstract

PURPOSE:To shield a control circuit from a noise produced in a large current circuit and avoid the misoperation of a small signal circuit by a method wherein an active filter having a circuit structure in which a reactor is connected between the output terminal of a rectifying circuit and a switching device is mounted on an insulated metal board in such a manner that the circuit elements of the filter to which large currents are applied are isolated from its small signal circuit elements by a ground pattern around the center of the circuit board. CONSTITUTION:A circuit board is divided into a small signal circuit block and a large current circuit block by a part of a grounding pattern. The large current circuit block is composed of a rectifying circuit, a switching device, diodes, etc. The small signal circuit is composed of a control circuit COM. Outer lead terminals through which the large current circuit block is connected to an external circuit are provided on the circumferential edge parts of the circuit board which are different from the circumferential edge parts on which the outer lead terminals of the small signal circuit block are provided. Therefore, noise crosstalk from the large current circuit block to the small signal circuit block through the outer lead terminals can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a hybrid integrated circuit device in which a power active filter is mounted on an insulated metal substrate, and in particular, the present invention relates to a hybrid integrated circuit device in which a power active filter is mounted on an insulated metal substrate. The present invention relates to a hybrid integrated circuit device that prevents malfunctions and suppresses leakage current from an insulated metal substrate to the outside due to switching operations.

(0) Prior Art In recent years, active filters have been attracting attention from the viewpoint of noise countermeasures for rectified power supplies. - A detailed active filter will be explained with reference to FIG.

The active filter consists of a bridge rectifier circuit consisting of diodes D, ~D4, a reactor connected between the AC input terminal of this bridge rectifier circuit and a commercial AC power supply indicated by voltage VIIe, and a pair of DC outputs of the bridge rectifier circuit. The circuit is composed of a transistor Q connected in parallel between terminals, a capacitor C1 that smoothes the DC output of the bridge rectifier circuit, and a damper diode D connected between the DC output terminal of the bridge rectifier circuit and the smoothing capacitor cd. Note that normally 15KH2 is used to control the operation of transistor Q.
A control circuit that generates eight control pulses φ having the above-mentioned frequency is omitted.

Next, the operation of this active filter will be explained.

In the half cycle when the reactor L side of commercial AC is positive,
While the transistor Q is turned on by the high-level control pulse φ, the reactor is connected to the diode D1 - the transistor Q.
- Diode D4 forms a closed circuit and current flows through reactor L, and during the half cycle when the reactor side of the commercial alternating current is negative, while transistor Q is on, diode D2 transistor Q - diode D3 - reactor A closed circuit is formed and current flows through the reactor as well. Then, when the control pulse φ becomes low level and the transistor Q is turned off, the previous two closed circuits are opened and a back electromotive force is generated in the reactor L. Since this back electromotive force is in the same phase as the commercial AC, while the transistor Q is turned off, the voltage that is the sum of the back electromotive force of the reactor L and the voltage of the commercial AC is input to the bridge rectifier circuit, and this rectified output is Damper diode D5 is forward biased and smoothing capacitor C6 is charged.

Conventionally, this active filter was constructed from discrete components, but the wiring between each discrete component became long, and the inductance component of the wiring induced new switching noise. For this reason,
It became necessary to house the active filter within a large shield structure, and the demand for downsizing of power supplies could not be met satisfactorily.

Therefore, the present inventor filed a patent application for a hybrid integrated circuit device in which this active filter was mounted on an insulated metal substrate.
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 coated with an insulating oxide film (42) formed by anodizing, and on one of the insulating oxide films (42), an insulating resin layer (e.g. ebo-shi) is coated. A copper foil circuit pattern (48) is formed through the copper foil (46). Then, on this circuit pattern (48), the diodes D1 to D5, the transistor Q, and the circuit components constituting the control circuit are surface-mounted in chip form, thereby realizing an extremely small active filter. . Furthermore, as is clear from Fig. 7, the circuit pattern (4
8), the ground pattern is an insulating oxide film (42)
In order to eliminate stray capacitance caused by the insulating resin layer (46), it is connected to the metal substrate under the insulating oxide film (42) by a bonding wire (54).

When such a hybrid integrated circuit device is incorporated into an electronic device, it is usually mounted in a structure with good heat dissipation by bringing the insulating oxide film (42) on the back surface of the metal substrate (40) into contact with the chassis. Therefore, in this structure, the stray capacitance C, (see Figure 8) with at least the insulating oxide film (42) as a dielectric between the metal substrate (40) and the chassis of the electronic device is
Wat ζ occurs over the entire surface.

(c) Problems to be Solved by the Invention However, in the hybrid integrated circuit device described above, the emitter potential of the transistor Q of the active filter fluctuates greatly at high frequencies, and this is transmitted to the chassis of the electronic device as noise through the insulated metal substrate. The use of an insulated metal substrate has a unique problem of leakage.

The cause of this problem will be explained with reference to FIGS. 8(A) and 8(B).

FIG. 8(A) shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the reactor side of commercial AC is positive. In the positive half-cycle, a closed circuit is formed by the reactor L-diode D, -transistor Q-diode-) D4, and the reactor L is in a position where it becomes the collector load of the transistor Q.

On the other hand, FIG. 8(B) shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the reactor side of commercial AC is negative. In the negative half cycle, a closed circuit is formed by diode D2-transistor Q-diode D3-reactor L, and reactor L becomes the emitter load of transistor Q.

As is clear from this, the positive half period (Figure 8 (A))
Then, the collector potential of the transistor Q changes so as to switch between the charging voltage of the smoothing capacitor C4 and the ground potential at a frequency of (control)<Rus φ. Note that the emitter potential is maintained at the ground potential. However, in the negative half cycle (Fig. 8 (B)), the reactor L becomes the emitter load of the transistor Q, so the emitter potential is switched between the charging voltage of the smoothing capacitor C4 and the ground potential at the frequency of the control pulse φ. It changes like this.

Since the ground pattern of the hybrid integrated circuit device and the aluminum substrate (40) are connected by the bonding wire (54), in the negative half cycle, the potential of the aluminum substrate (40) is equal to the charging voltage of the smoothing capacitor C4. and the ground potential at the frequency of the control pulse φ.

This flows out as switching noise to the chassis of the electronic device via the stray capacitance C2 formed between the aluminum substrate (40) and the chassis of the electronic device.

Furthermore, in the hybrid integrated circuit device described above, switching noise generated by its main circuit mixes into small signal circuits such as the control circuit for controlling transistor Q through capacitive and inductively coupled circuit patterns, causing the operation of the hybrid integrated circuit device. There was a risk of damage to the

(d) Means for solving the problem The present invention was made in view of the problem, and the large current flows through an active filter having a circuit configuration in which a reactor is connected between the output end of a rectifier circuit and a switching element. By mounting circuit elements and small-signal circuit elements on an insulated metal substrate so that they are separated by a ground pattern approximately in the center of the circuit board, we have created a hybrid integrated circuit device that greatly improves the problems of conventional circuits. It is something that will be realized.

(E) The active filter has a circuit configuration in which a reactor is connected to the DC output end of the working rectifier circuit and the other end of the reactor is intermittently grounded by a switching element, so it can be used in any phase of the commercial AC. , the reactor acts as a collector load for the transistor, eliminating the application of high frequency switching voltage to the ground pattern.

Therefore, no high frequency switching voltage is applied to the metal substrate connected to the ground pattern, and switching noise can be prevented from leaking to the outside via stray capacitance caused by the mounting structure of the hybrid integrated circuit device.

In addition, because the circuit elements through which large currents flow and the small signal circuit elements are separated by a ground pattern approximately in the center of the circuit board, noise caused by large current switching operations is shielded by the ground pattern and small signal circuit elements are separated. Malfunction of the circuit is prevented.

(f) Embodiment FIG. 1 shows the circuit configuration of a characteristic active filter adopted in the present invention.9 As shown in the same figure, this active filter has
A bridge rectifier circuit consisting of diodes D1 to D4, which is a feature of the present invention, is a reactor whose one end is connected to the positive DC output end of the bridge rectifier circuit, and whose collector and emitter are respectively connected between the other end of this reactor L and the ground. This transistor Q. The damper diode D5 has an anode connected to the collector of the damper diode D5, a smoothing capacitor C6 is connected between the cand of the damper diode D5 and the ground, and a control circuit COM supplies a control pulse φ to the base of the transistor Qo.

The main circuit of the control circuit CQM is constituted by a microcomputer and outputs a control pulse φ having a frequency of 15KH2 or more. Although not shown, the control circuit COM detects the magnitude of the load current and performs feedback control based on the frequency of the control pulse φ or the duty, and further controls the substrate temperature and the transistor Q.

It also measures the emitter current of the active filter and performs control to prevent thermal runaway. Although a microcomputer was used for the control circuit COM in this embodiment,
In addition, predetermined control can be performed using well-known circuit configurations such as comparators and operational amplifiers.

The transistor Q is not limited to the illustrated bipolar structure transistor, but can be changed to other elements capable of high-speed operation, such as a power MO3 transistor, SIT, or IGBT. Further, the rectifier circuit is not limited to the illustrated bridge rectifier circuit, and any known type of rectifier circuit can be used.

Next, the operation of the active filter configured as described above will be explained with reference to FIG.

In the half cycle in which the potential at the connection point between the commercial AC diode FD and D2 is positive, 1 5 is output from the control circuit COM.
Transistor Q when control pulse φ with a frequency of KHz or higher is at high level. turns on, diode D, - reactor L - transistor Q. - A closed circuit of diode D4 is formed and current iL flows through the reactor. And when the control pulse φ is at low level, the transistor Q. When the reactor is turned off and the previously closed circuit is opened, the reactor generates a back electromotive force in an attempt to maintain the previous electrical state.

The voltage obtained by adding the back electromotive force of the reactor L and the output of the bridge rectifier circuit exceeds the charging voltage of the smoothing capacitor C4 for a long period of time compared to a capacitor input type rectifier circuit, and is connected to the smoothing capacitor via the damper diode D5. Charge C2.

Furthermore, in the half cycle in which the potential at the connection point between the commercial AC diodes D and D2 becomes negative, the transistor Q when the control pulse φ is at a high level. is turned on, a closed circuit of diode D3-reactor, transistor Q0-diode D2 is formed, and current LL flows through the reactor. Then, the control pulse φ becomes low level and the transistor Q. is turned off and the previous closed circuit is opened, a back electromotive force is generated in the reactor as before, and the smoothing capacitor C4 is charged by the voltage obtained by adding the back electromotive force and the output of the bridge rectifier circuit.

This will be explained in more detail with reference to FIGS. 3(A) and 3(B).

FIG. 3(A) shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the potential at the connection point of commercial AC diodes D1 and D2 becomes positive. In this positive half cycle, diode D, ~ reactor L - transistor Q. -Diode D
A closed circuit is formed by A, and reactor L is connected to transistor Q. It is located at a position where the collector is loaded.

On the other hand, Fig. 3 (B) shows the commercial AC diode D.
, and shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the potential at the connection point of D2 becomes negative. In the negative half cycle, diode D2 - reactor L - transistor Q. - A closed circuit is formed by the diode D3, and the reactor L is connected to the transistor Q in the same way as in the positive half cycle. This is a collector load.

Therefore, according to the circuit configuration of this active filter, the transistor Q is always a reactor in both the positive half cycle and the negative half cycle of the commercial AC. Since it is pushed into the collector side of the transistor. . The emitter potential of is always stable at ground potential.

Referring to FIG. 4, a detailed structure of an embodiment in which the above-described active filter is mounted on an insulated metal substrate except for the reactor and smoothing capacitor C7 will be described.

The circuit pattern with diagonal lines is the ground pattern, and the circuit board uses a part of the ground pattern to connect the small signal circuit block corresponding to the blank area in the half of the road on the drawing and the large current corresponding to the lower half of the drawing. In this embodiment, the wiring for the control pulse φ supplied from the small signal circuit block to the large current circuit block, or the transistor Q supplied from the large current circuit block to the small signal circuit block. The emitter potential wiring is formed so as to bypass a part of the ground pattern, but is not limited to this, for example, the emitter potential wiring of the transistor Q. The emitter potential wiring may be connected to a predetermined position of the small signal block by a bonding wire (jumping wire connection).

Furthermore, this ground pattern is a transistor Q through which high frequencies and large currents flow. It is connected to the aluminum substrate by a bonding wire W at a position closest to the emitter of the aluminum substrate to make the aluminum substrate potential equal to the ground pattern potential.

The large current circuit block includes diodes D, ~D4, a damper diode D6, and a transistor Q that constitute a bridge rectifier circuit. is surface mounted via a heat sink, and further a transistor Q. An emitter resistor R is formed to limit the emitter current of and measure its value. These elements are arranged so that a large current does not flow into the ground pattern portion that divides the small signal circuit block and the large current circuit block. This further improves the shielding effect of this ground pattern section. Furthermore, the external lead terminals for connecting the large current circuit block and the external circuit are arranged on a peripheral edge of the circuit board that is different from the peripheral edge where the external lead terminals of the small signal circuit block are arranged, and these external lead terminals This prevents noise from entering the small signal circuit block from the large current circuit block via the circuit block.

Also, since the distance between the externally connected smoothing capacitor C4 and the damper diode D5 greatly affects the performance of the active filter, the damper diode D is placed close to the terminal indicated by ■ in Figure 4. Also, based on the same reasoning, the terminal indicated by V+ and the ground terminal GND are arranged adjacent to each other.

Note that the cross-sectional structure of the hybrid integrated circuit device shown in FIG. 4 is the same as that in FIG. 7, so a description thereof will be omitted.

The above-described hybrid integrated circuit device of the present invention is mounted on the chassis of an electronic device by bringing the back surface of the insulating metal substrate into contact with the chassis of the electronic device, taking heat dissipation into consideration. For this reason, a stray capacitance C2 is interposed between the metal substrate of the insulated metal substrate and the chassis as shown in FIG. 3. However, since the metal substrate is connected to the ground (shaded area in Figure 4) by the bonding wire W, the potential is the same as that of the ground pattern.

According to the invention, the ground pattern, i.e. transistor Q. Since the emitter potential of C9 is stable at the ground potential as described above, there is no possibility that switching noise will flow into the chassis during the negative half cycle of the commercial flow through this stray capacitance C9.

FIG. 5 shows a circuit diagram of a modification of the embodiment.

The control circuit COM of the above embodiment has a function of outputting multiphase pulses for controlling the inverter circuit, and outputs the multiphase pulses from the hybrid integrated circuit device to the outside. Although such a hybrid integrated circuit device has the advantage that it can be constructed on a relatively small scale, it has the disadvantage that it requires a large number of terminals for externally outputting multiphase pulses.

On the other hand, in a modified example, a three-phase inverter circuit composed of transistors Q, ~Q6 is also mounted on a single circuit board, and transistors Q1 ~ Q6 are connected to the control circuit COM via a circuit pattern formed on the circuit board. Multiphase pulses are manually applied to the base of Q6.

This reduces the number of terminals and prevents noise from entering the wiring between the active filter and the inverter circuit.

(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 ground potential at high frequencies, the metal of the hybrid integrated circuit device There is no fear of switching noise leaking from the board 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 the large current circuit and the control circuit are separated by a ground pattern, the control circuit is shielded from noise generated in the large current circuit.

(3) Due to the use of hybrid integrated circuit devices, the wiring between the elements that make up the active filter becomes shorter, which suppresses noise caused by wiring inductance9 (4) Since an insulated metal substrate is used as the circuit board, the wiring pattern and A relatively large stray capacitance is formed between the metal substrates, and harmonic noise can be quickly attenuated in the vicinity of the point where it is generated.

(5) Since an insulated metal substrate is used as the circuit board, heat dissipation 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 explanation of the drawing]

Fig. 1 is a circuit diagram explaining the active filter adopted in the present invention, Fig. 2 is an operating waveform diagram of the active filter, and Fig. 3 (A) and (B) explain changes in emitter potential of the transistor of the present invention. 4 is a plan view of the embodiment, FIG. 5 is a circuit diagram of a modified example, and FIG. 6 is an active circuit diagram of a conventional example.
The circuit diagram of the filter, FIG. 7 is a cross-sectional view of the circuit board, and FIGS. 8(A) and 8(B) are diagrams explaining changes in the emitter potential of a conventional transistor, each showing the equivalent value of each half cycle of commercial AC. It is a circuit diagram. L...-reactor, D1~D5-diode, cd
...Smoothing capacitor, Qo...transistor, C
OM...control circuit. Ganto Hatake Sanyo Electric Co., Ltd.

Claims (5)

[Claims] (1) On the circuit pattern of the insulated metal board,
At least a rectifier circuit, a switching element, a diode for extracting charging voltage from the switching element, and a control circuit for controlling the switching element are implemented, and a reactor is connected between the DC output terminal of the rectifier circuit and the switching element, and the A hybrid integrated circuit device in which a charging capacitor is connected to the output side of the diode, and a connection part is provided to connect the ground pattern of the circuit pattern and the metal substrate, and the device is provided with a connection part that connects the ground pattern of the circuit pattern and the metal substrate, 1. A hybrid integrated circuit device, wherein a large current circuit and a small signal circuit such as the control circuit are separated by a ground pattern approximately at the center of the substrate. (2) The hybrid integrated circuit device according to claim 1, wherein the insulating metal substrate is coated with an oxide film formed by anodizing the surface of an aluminum substrate. (3) The hybrid integrated circuit device according to claim 1, wherein the rectifier circuit is a bridge rectifier circuit. (4) The hybrid integrated circuit device according to claim 1, wherein the switching element is composed of a bipolar transistor, a MOS transistor, an SIT, or an IGBT. (5) The hybrid integrated circuit device according to claim 1, wherein the connection portion is formed of a bonding wire.