JPH0433392A - Hybrid integrated circuit device - Google Patents

Abstract

PURPOSE:To prevent the outflow of a switching noise through a stray capacitance by mounting an active filter having such circuit constitution that plural unit circuits composed of a reactor, a transistor and a diode are arranged between an output terminal of a rectifier circuit and a smoothing capacitor and the reactor is specially and intermittently grounded, on an insulating metal substrate. CONSTITUTION:A circuit board is divided into a small signal circuit block and a large current circuit block by a ground pattern. The ground pattern in connected to an aluminum circuit board by a bonding wire W in the place near an emitter of either of transistors Q1 and Q2 in which a high frequency and a large current flow and a potential of the aluminum circuit board is made equal to a potential of the ground pattern. In the large current circuit block, diode D1-D4, damper diodes D5 and D6, and transistors Q1 and Q2 are surface- mounted through a heat sink. Further, emitter currents of the transistors Q1 and Q2 are limited and emitter resistances R1 and R2 are arranged so as to prevent a large current from flowing into the ground pattern part.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field 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 suppresses leakage current to and reduces output voltage fluctuations.

(b) Conventional technology In recent years, active filters have been attracting attention from the perspective of noise countermeasures for rectified power supplies. - A membrane active filter will be explained with reference to FIG.

The active filter is a bridge rectifier circuit consisting of diodes D1 to D4, and an AC input terminal of this bridge rectifier circuit and a voltage. A reactor connected between the commercial AC power supplies shown in , a transistor Q connected in parallel between the pair of DC output terminals of the bridge rectifier circuit, a capacitor C1 that smoothes the DC pressure of the bridge rectifier circuit, and a DC output of the bridge rectifier circuit. The circuit consists of a damper diode D5 connected between the terminal and the smoothing capacitor cd. Note that a control circuit that normally outputs a control pulse φ having a frequency of 15KH2 or more for controlling the operation of the transistor Q 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 transistor Q is turned on by high-level control pulse φ, reactor L - diode D, - transistor Q
- Diode D forms a closed circuit and current flows to the reactor, and during the half cycle when the reactor side of commercial AC is negative, while transistor Q is on, diode D2 - transistor Q - diode D, - A closed circuit is formed by the reactor, 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. 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 The damper diode D is forward biased and the smoothing capacitor C1 is charged.

Conventionally, this active filter was composed of 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.
It was proposed in issue 580. This hybrid integrated circuit device will be explained 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 (46) of epoxy or the like is formed. A copper foil circuit pattern (48) is formed through the copper foil. Then, on this circuit pattern (48), diodes D, ~D4, transistor 6, transistor Q, and circuit components constituting the control circuit are surface-mounted in chip form to realize an extremely small active filter. There is. 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, between the metal substrate (40) and the chassis of the electronic device, there is at least a stray capacitance C, (see FIG. 8) with the insulating oxide film (42) as a dielectric.
) occurs throughout the area.

(c) Problems to be Solved by the Invention However, in the active filter shown in FIG. 5, power is not transmitted to the load side when transistor Q is on, and only when transistor Q is off. Since power is transmitted to the load side, there is a problem in that the power transmission is intermittent and pulsation occurs when viewed from the load side, increasing noise to the outside and increasing the ripple current of the smoothing capacitor C2.

In addition, the hybrid integrated circuit device equipped with this active filter uses an insulated metal substrate, in which the emitter potential of transistor Q fluctuates greatly at high frequencies, which flows out as noise to the chassis of the electronic device via the insulated metal substrate. has its own unique problems.

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

FIG. 7(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, reactor L diode D, - transistor Q - diode D.

A closed circuit is formed, and the reactor L is connected to the transistor Q
It is located at a position where the collector is loaded.

On the other hand, FIG. 7(B) shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the reactor side of the commercial AC becomes negative. In the negative half cycle, a closed circuit is formed by diode D2-transistor Q-diode D3-reactor, and reactor L becomes the emitter load of transistor Q.

As is clear from this, the positive half period (Figure 7 (A))
Then, the collector potential of the transistor Q changes so as to switch between the charging voltage of the smoothing capacitor cd and the ground potential at the frequency of the control pulse φ. Note that the emitter potential is maintained at the ground potential. However, the negative half period (
In FIG. 7(B)), since the reactor L serves as an emitter load for the transistor Q, the emitter potential changes so as to switch between the charging voltage of the smoothing capacitor C4 and the ground potential at the frequency of the control pulse φ.

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

This flows into the synergy of the electronic device as switching noise via the stray capacitance CP formed between the aluminum substrate (40) and the chassis of the electronic device.

(d) Means for Solving the Problems The present invention has been made in view of the above problems, and consists of a plurality of unit circuits each consisting of a reactor, a transistor, and a diode arranged in parallel between the output end of a rectifier circuit and a smoothing capacitor. An active circuit configuration that specifically and intermittently grounds the reactor.
By mounting a filter on an insulated metal substrate, a hybrid integrated circuit device is realized which greatly improves the problems of the conventional technology.

(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 the active filter is made into a hybrid integrated circuit device. The reactor acts as a collector load for the transistor, eliminating the application of high frequency switching voltages to the ground trace.

Therefore, no high frequency switching voltage is applied to the metal substrate connected to the ground pattern, thereby preventing external flow pressure of switching noise through stray capacitance caused by the mounting structure of this hybrid integrated circuit device.

In addition, because we have adopted a circuit configuration in which multiple unit circuits consisting of reactors, transistors, and diodes are arranged in parallel between the output end of the rectifier circuit and the smoothing capacitor as an active filter, charging and discharging operations of each reactor can be performed independently. It becomes possible to charge at least 61 of the plurality of reactors from the rectifier circuit at any timing,
Since the smoothing capacitor is charged from at least 61 of the plurality of actuators, the AC input current and the charging current of the smoothing capacitor become the sum of the currents flowing through the plurality of actuators, and the level of harmonic noise is reduced.

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

This active filter, as shown in the figure,
A bridge rectifier circuit consisting of diodes D1 to D4, a plurality of reactors L1 to L3, one end of which is connected to the positive DC output end of the bridge rectifier circuit, and a collector and an emitter connected between the other ends of reactors 1 to L3 and ground, respectively. A plurality of transistors Q, ~Q3, transistors Q, ~Q3
Damper diodes D5 to D7 have anodes connected to their respective collectors and cathodes commonly connected, a smoothing capacitor C1 connected to the caps of the dampers and diodes FD5 to D7, and a transistor (not shown). A control pulse φ is applied to each base of Q1 to Q3,
It is composed of a control circuit COM that supplies φ3.

The illustrated embodiments include reactors, transistors and dampers.
Although three sets of unit circuits each consisting of diodes are provided, the number of unit circuits may be two or any number greater than or equal to four.

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. Although not shown, this 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.
. The emitter current of the active filter is measured to control the active filter so that it does not run away thermally.Although a microcomputer was used for the control circuit COM in this embodiment, other well-known devices such as comparators and operational amplifiers are also used. Predetermined control can also be performed depending on the circuit configuration.

The transistors Q1 to Q3 are not limited to the illustrated bipolar structure transistors, but can be changed to other elements capable of high-speed operation, such as power MOS transistors, SITs, and IGBTs. 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 illustrated embodiment, the control pulses φ1 to φ3 inputted to the respective terminals of the plurality of transistors Q1 to Q are pulses having a phase difference of 120 degrees from each other.

When this control pulse φ1 becomes high level and turns on the transistor Q1, a current 11,1 flows through the reactor L1 due to the output of the bridge rectifier circuit. And the control pulse φ
1 becomes low level and the transistor Q1 is turned off, the reactor L1 attempts to maintain the previous electrical state and generates a back electromotive force. The back electromotive force of this reactor L has the same polarity as the output of the bridge rectifier circuit, and the voltage added thereto starts charging the smoothing capacitor C4.

At the timing when the control pulse φ1 becomes low level, the transistor Q2 is turned on by the control pulse φ2 independently of the above operation, and the current IL2 begins to flow into the reactor L2, so that charging of the smoothing capacitor C1 by the reactor L1 ends. Shortly thereafter, the smoothing capacitor cd is charged by the reactor L2.

Thereafter, similarly, reactors L, ~L3, transistors Q, ~
A unit circuit constituted by Q3 and damper diodes D, ~D6 sequentially reacts 1~L.

Performs charging and discharging operations.

In the active filter of the present invention that operates as described above, the commercial alternating current 1. . and smoothing capacitor charging current lad
Since the waveform of is the sum of the currents flowing through each reactor L1 to L1, the commercial AC voltage waveform . , the level of harmonic noise is reduced, and the ripple in the capacitor charging current and the high frequency noise it generates is reduced.

The operation will be further explained 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 D1 - reactor L - transistor Q. -Diode D
4 forms a closed circuit, and the reactor L is the 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.
1 shows an equivalent circuit of the hybrid integrated circuit device in a half cycle in which the potential at the connection point between 1 and D2 becomes negative. In the negative half cycle, diode-1'D2-reactor L,-transistor Q0
- A closed circuit is formed by the diode D, and the reactor is connected to the positive half cycle as well as the transistor Q. This is a collector load.

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

Referring to FIG. 4, a specific structure of an embodiment in which the above-described active filter, excluding the reactor L and smoothing capacitor C4, is mounted on an insulated metal substrate will be described. Note that this figure shows an example in which two unit circuits each consisting of a reactor, a transistor, and a damper diode are arranged in parallel.

The circuit pattern with diagonal lines is the ground pattern, and the circuit board has a part of the ground pattern.
It is divided into two parts: a small signal circuit block corresponding to the blank area in the upper half of the drawing, and a large current circuit block corresponding to the lower half of the drawing. In this embodiment, the wiring for the control pulses φ1 and φ2 supplied from the small signal circuit block to the large current circuit block or the wiring for the emitter potential of transistors Q1 and Q2 supplied from the large current circuit block to the small signal circuit block are as described above. Although it is formed so as to bypass a part of the ground pattern, it is not limited to this, and it may be connected by a jumping wire.

Furthermore, this ground pattern is connected to the aluminum substrate with a bonding wire W at a position near the emitter of either transistor Q1 or Q2, through which high frequency and large current flows, to make the aluminum substrate potential equal to the ground pattern potential. There is.

The large current circuit block includes diodes D1 to D4 that constitute a bridge rectifier circuit, damper diodes D5 and D6,
Transistors Q, Q2 are surface-mounted via a heat sink, and an emitter resistor R is provided to limit the emitter current of transistors Q7 and Q2 and to measure its value.
1, R2 is formed. 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 1D block.

The external lead terminals that connect the large current circuit block and the external circuit and the external lead terminals of the small signal block are arranged on opposite peripheral edges of the circuit board so that they are loosely coupled 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 hybrid integrated circuit device of the present invention is mounted on the chassis of an electronic device by bringing the back surface of an insulated metal substrate into contact with the chassis of an electronic device, taking heat dissipation into consideration. At this point tζ, a stray capacitance CP 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 pattern (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 is stabilized 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 AC via this stray capacitance c2.

(1) 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 high frequencies, the metal substrate of the hybrid integrated circuit device There is no risk of switching noise leaking into the chassis of electronic equipment, and a hybrid integrated circuit device equipped with an extremely small active filter can be realized.

(2) Since we adopted a circuit configuration in which multiple unit circuits consisting of reactors, transistors, and diodes are installed in parallel between the output end 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 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 granoid pattern, the control circuit is shielded from noise generated in the large current circuit.

(4) Since the inter-element wiring constituting the active filter becomes shorter due to the use of a hybrid integrated circuit device, noise caused by 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, and harmonic noise can be rapidly attenuated in the vicinity of the point where it occurs.

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

(7) 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]

Figure 1 is a circuit diagram explaining the active filter adopted in the present invention, Figure 2 is an operating waveform diagram of the active filter, and Figures 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 conventional active filter, and FIG. 6 is a cross-sectional view of a circuit board. , and FIGS. 7(A) and 7(B) are diagrams illustrating changes in emitter potential of a conventional transistor, and are equivalent circuit diagrams for each half cycle of a commercial alternating current. L1-L3...Reactor, D1-D7...Diode, C4...Smoothing capacitor, Q, ~Q3-...Transistor.

Claims (5)

[Claims] (1) On the circuit pattern of the insulated metal board,
In a hybrid integrated circuit device that includes at least a rectifier circuit constituting a filter, a plurality of switching elements, and a plurality of diodes whose one end is connected to each of the plurality of switching elements and whose other end is commonly connected, the DC output terminal of the rectifier circuit and a plurality of reactors are connected between each of the switching elements, a charging capacitor is connected to the common connection end of the diode, and a connection part is provided to connect the ground pattern of the circuit pattern and the metal substrate. A hybrid integrated circuit device characterized by: (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.