JP2012228046A - Power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem of a multi-output power supply that a high voltage is output to the output side of a DC/DC converter unit, in operation stop state of output off, by an output leakage current voltage generated from the DC/DC converter unit, in operational state of output on, to possibly cause electrical shock.SOLUTION: The multi-output power supply comprises a DC power supply 10 which outputs DC power from output terminals 13a, 13b, and a plurality of DC/DC converter units 20 connected in parallel with the output terminals 13a, 13b. Capacitors 41, 42 are connected, respectively, between the output terminals 13a, 13b and the GND. The pulse of an output leakage voltage generated from the DC/DC converter unit 20, in operational state of output on, flows to the capacitors 41, 42. Consequently, a high voltage generated on the load side of the DC/DC converter unit, in operation stop state of output off, can be reduced.

Description

  The present invention relates to a multi-output power supply device including a plurality of DC / DC (hereinafter referred to as “DC / DC”) converter units, and more particularly to a technique for reducing output leakage voltage in a DC / DC converter unit. .

  Conventionally, a power supply device such as a DC sputtering power supply device described in Patent Document 3 or the like includes a DC / DC converter unit that inputs DC power and converts the DC power into a predetermined level of DC power.

  A technique is known in which a plurality of DC / DC converter units are used and a plurality of DC / DC converter units are connected in parallel to a common DC power supply to form a multi-output power supply apparatus. In a multi-output power supply device, a load such as a DC sputtering device is connected to a plurality of output terminals, DC power is supplied to each load, and a plurality of loads can be operated in parallel.

  Patent Documents 1 and 2 describe that an output leakage voltage is generated between output terminals in a multi-output power supply device having a plurality of output terminals.

JP 2005-261115 A JP 2005-143154 A JP 2009-232542 A

  In a conventional multi-output power supply device, when there is a DC / DC converter unit in an output-on operation state among a plurality of DC / DC converter units, this output leakage voltage causes a DC / DC converter in an output-off stop state. A high voltage was output to the output side of the unit, and there was a risk of electric shock due to the generation of this high voltage.

  A power supply device according to a first aspect of the present invention includes a common DC power source that outputs first DC power from a first positive electrode side output terminal and a first negative electrode side output terminal, and the first positive electrode side. A plurality of DC / DC converter units that are connected in parallel to the output terminal and the first negative output terminal and output the second DC power to individual loads, respectively.

  Each of the DC / DC converter units is connected to the first positive electrode side output terminal and the first negative electrode side output terminal, and has a first positive electrode side input terminal and a first positive electrode side input terminal for inputting the first DC power. 1 negative input terminal, a DC / DC converter that converts the input first DC power into the second DC power at a predetermined level, and the converted second DC power into the individual load A second positive output terminal and a second negative output terminal that respectively output to the first output terminal. Further, a first capacitor is connected between the first positive output terminal and the ground electrode, and a second capacitor is connected between the first negative output terminal and the ground electrode. It is connected.

  In the power supply device of the second invention, instead of the first and second capacitors of the first invention, between the first positive electrode side input terminal and the ground electrode in each DC / DC converter unit. A third capacitor is connected, and a fourth capacitor is connected between each first negative input terminal and each ground electrode in each DC / DC converter unit.

  According to a third aspect of the present invention, there is provided the power supply device according to the second aspect, wherein a first capacitor is connected between the first positive output terminal and the ground electrode, and further, the first capacitor A second capacitor is connected between the negative output terminal and the ground electrode.

  According to the power supply devices of the first, second and third inventions, the current due to the output leakage voltage from the DC / DC converter unit in the output-on operation state to the DC / DC converter unit in the output-off stop state is It flows to the ground electrode side via the first and second capacitors, or the third and fourth capacitors. Therefore, the voltage generated from the DC / DC converter unit in the output-off stopped state to the load side can be reduced to a level that does not cause an electric shock.

FIG. 1 is a schematic configuration diagram illustrating a power supply device according to a first embodiment of the present invention. FIG. 2 is a circuit diagram showing a configuration example of each DC / DC converter unit in FIG. FIG. 3 is an operation waveform diagram showing the pulse P1 and the leakage voltage pulse P2 inside the DC / DC converter in FIG. FIG. 4 is a circuit diagram showing a configuration example of each DC / DC converter unit in the second embodiment of the present invention.

  Modes for carrying out the present invention will become apparent from the following description of the preferred embodiments when read in light of the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Configuration of Example 1)
FIG. 1 is a schematic configuration diagram illustrating a power supply device according to a first embodiment of the present invention.

  This power supply device is, for example, a multi-output DC sputtering power supply device, and includes a common DC power supply 10 that supplies first DC power. The DC power source 10 is connected to an AC power source 11 that supplies first alternating current (hereinafter referred to as “AC”) power (for example, three-phase (3φ) 200 volts (V)), and an output side of the AC power source 11. And a first positive electrode side output terminal 13a and a first negative electrode side output terminal 13b connected to the output side of the rectifier circuit 12. The rectifier circuit 12 is a circuit that half-wave rectifies the three-phase first AC power supplied from the AC power 11 and outputs the two-phase first DC power from the positive output terminal 13a and the negative output terminal 13b. It is composed of six rectifier diodes 12a to 12f that perform half-wave rectification for each phase. The rectifier circuit 12 may be a full-wave rectifier circuit, or a smoothing circuit formed of an inductor, a capacitor, and the like may be provided on the output side.

  A plurality of DC / DC converter units 20 (= 20-1 to 20−) are connected to the positive output terminal 13a and the negative output terminal 13b of the DC power supply 10 via the positive power supply line 14a and the negative power supply line 14b. N) are connected in parallel. Each DC / DC converter unit 20 converts the first DC power supplied from the common DC power supply 10 into second DC power of a predetermined level (for example, constant power, constant voltage power, or constant current power). And output to individual loads 36.

  Each DC / DC converter unit 20 includes a first positive input terminal connected to the positive output terminal 13a and the negative output terminal 13b of the DC power supply 10 via the positive power supply line 14a and the negative power supply line 14b. 21a and the first negative electrode side input terminal 21b and the first DC power input from the first positive electrode side input terminal 21a and the first negative electrode side input terminal 21b are converted into second DC power of a predetermined level. And a second positive electrode side output terminal 35a and a second negative electrode side output terminal 35b for outputting the converted second DC power to the individual loads 36.

  The DC / DC converter 30 is, for example, an insulation type DC / DC converter, and switches the first DC power input from the positive electrode side input terminal 21a and the negative electrode side input terminal 21b to convert it into second AC power. A switch (SW) unit 31, a transformer (hereinafter referred to as “transformer”) 32 that converts the first voltage in the converted second AC power into a second voltage of a predetermined level, and the converted second And a rectifying unit 33 that rectifies the third AC power having the voltage and outputs the second DC power.

  A positive output terminal 35 a and a negative output terminal 35 b are connected to the output side of the rectifying unit 33 via a smoothing unit (for example, a smoothing capacitor) 34 that smoothes the output power of the rectifying unit 33.

  For example, a DC sputtering device is connected as a load 36 to the positive output terminal 35a and the negative output terminal 35b. The DC sputtering apparatus is an apparatus used for forming a metal thin film, a dielectric thin film, or the like on a substrate surface used in, for example, a semiconductor device or a liquid crystal display device, and includes a vacuum chamber and an exhaust device. Yes. In the vacuum chamber, a target to be a material for depositing a thin film, a substrate for depositing the thin film by sputtering the target, and the like are accommodated. When sputtering a target, for example, after the vacuum chamber is evacuated to vacuum, a plasma generating gas is introduced into the chamber, and after the vacuum chamber reaches a predetermined pressure, the vacuum chamber is set as a positive electrode and the target is set as a negative electrode. Apply DC voltage. Then, plasma is generated in the vacuum chamber, the target material is sputtered, and the target material is deposited on the substrate to form a thin film.

  A control circuit 40 is connected to the switch unit 31 in each DC / DC converter unit 20. The control circuit 40 is a circuit that controls the switching operation of each switch unit 31 by outputting a switch switching signal S40 that has been subjected to pulse width modulation (PWM).

  A first capacitor 41 is connected between the positive power supply line 14a connected to the positive output terminal 13a of the DC power supply 10 and the ground GND which is a ground electrode. Similarly, a second capacitor 42 is connected between the negative power supply line 14b connected to the negative output terminal 13b of the DC power supply 10 and the ground GND as a ground electrode.

  The broken line arrow in FIG. 1 is the leakage voltage pulse path CS1 when the capacitors 41 and 42 are not present, and the solid line arrow is the leakage voltage pulse path CS2 when the capacitors 41 and 42 are present.

FIG. 2 is a circuit diagram showing a configuration example of each DC / DC converter unit 20 in FIG.
In the DC / DC converter 30 constituting each DC / DC converter unit 20, the switch unit 31 includes four switching elements (for example, N-channel MOS transistors, hereinafter referred to as “NMOS”) 31a to 31d. NMOS transistors 31a to 31d are bridge-connected to the positive input terminal 21a and the negative input terminal 21b. Each of the NMOSs 31a to 31d is turned on / off by a gate being controlled by a switch switching signal S40 provided from the control circuit 40.

  A transformer 32 is connected to a connection point 31e between the NMOSs 31a and 31c and a connection point 31f between the NMOSs 31b and 31d. The transformer 32 includes a primary winding 32a having a winding number n1 and a secondary winding 32b having a winding number n2. The winding start and winding end of the primary winding 32a are connected to connection points 31e and 31f, respectively. Yes. The rectifying unit 33 is connected to the winding end and winding start of the secondary winding 32b.

  The rectifier 33 is a circuit for full-wave rectifying the induced current flowing through the secondary winding 32b, and includes four rectifier diodes 33a to 33d, which are bridge-connected between the connection points 33e and 33f. A positive output terminal 35a and a negative output terminal 35b are connected to the cathodes of the rectifier diodes 33a and 33b and the anodes of the rectifier diodes 33c and 33d through a smoothing capacitor 34, respectively.

(Operation of Example 1)
FIG. 3 is an operation waveform diagram showing the pulse P1 and the leakage voltage pulse P2 inside the DC / DC converter in FIG.

  In FIG. 1, when performing parallel operation of a plurality of DC / DC converter units 20, AC power is output from the AC power supply 11 in the DC power supply 10, and this AC power is output by the rectifier diodes 12 a to 12 f in the rectifier circuit 12. Half-wave rectified and rectified DC power is output from the positive output terminal 13a and the negative output terminal 13b. The output DC power is supplied to each DC / DC converter unit 20 (= 20-1 to 20-N) via the positive power line 14a and the negative power line 14b. In each DC / DC converter unit (for example, 20-1), the supplied DC power is input from the positive electrode side input terminal 21a and the negative electrode side input terminal 21b and sent to the switch unit 31.

  In the switch unit 31 of FIG. 2, when the NMOSs 31 a and 31 d are turned on by the switch switching signal S <b> 40 given from the control circuit 40, the DC current of the DC power input from the positive input terminal 21 a is The current flows from the primary winding 32a → the NMOS 31d → the negative input terminal 21b. Next, when the NMOSs 31b and 31c are turned on, a DC current of DC power input from the positive input terminal 21a flows from the NMOS 31b → the primary winding 32a of the transformer 32 → the NMOS 31c → the negative input terminal 21b. .

  When DC currents having different directions flow alternately in the primary winding 32 a of the transformer 32, an AC induction current flows in the secondary winding 32 b of the transformer 32. The AC induced current is full-wave rectified by the rectifier diodes 33a to 33d in the rectifier 33, and then smoothed by the capacitor 34. The smoothed DC power is supplied from the positive output terminal 35a and the negative output terminal 35b. It is output and supplied to the load 36. Thereby, the load 36 performs a predetermined operation.

  The same operation is performed in the other DC / DC converter units 20-2 to 20-N, DC power is supplied to each load 36, and a plurality of loads 36 are operated in parallel.

  Here, for example, as in the prior art, when the DC / DC converter units 20-2 to 20-N are in the operating state without the capacitors 41, 42, the DC / DC converter unit 20-1 is in the stopped state and the load 36 Becomes a no load 36a close to infinity, a high voltage may be generated at the positive output terminal 35a and the negative output terminal 35b of the DC / DC converter unit 20-1, which may cause an electric shock. there were.

  When the DC / DC converter unit 20-1 is stopped and the load 36 becomes no load 36a, for example, the DC / DC converter unit is used for repairing and checking the vacuum chamber or the like where the worker is the load 36. The power supply supplied to 20-1 may be turned off, and the load 36 may be disconnected from the positive output terminal 35a and the negative output terminal 35b.

  As a cause of the load side high voltage generation of the DC / DC converter unit 20-1, the internal pulse P1 as shown in FIG. 3 in the DC / DC converter units 20-2 to 20-N in the operating state is shown in FIG. This is because the whisker-like leakage voltage pulse P2 as shown in FIG. 1 is guided to the DC / DC converter unit 20-1 through the path CS1 indicated by the broken line arrow shown in FIG. The load-side high voltage is generated when the DC / DC converter unit 20-1 is in a stopped state and the load 36 is a no-load 36a close to infinity. If the load 36 has a low impedance, the voltage does not cause an electric shock. As a specification of the DC / DC converter 30, since the output voltage is high, the turn ratio (n2 / n1) of the primary winding 32a and the secondary winding 32b of the internal transformer 32 is high. As a result, the leakage voltage pulse P2 is transmitted to the load side at a turn ratio, which is a factor that is likely to occur.

  In order to prevent the occurrence of such a load side high voltage, in the first embodiment, a capacitor 41 is provided between the positive power supply line 14a connected to the positive output terminal 13a of the DC power supply 10 and the ground GND. A capacitor 42 is connected between the negative power supply line 14b connected to the negative output terminal 13b and the ground GND. Therefore, the harmonic current caused by the leakage voltage pulse P2 generated from the DC / DC converter units 20-2 to 20-N is, as shown by the solid line arrow path CS2 in FIG. 1, the positive-side power line 14a and the negative-side power line. It flows to the capacitors 41 and 42 via 14b. As a result, the harmonic current due to the leakage voltage pulse P2 does not flow out to the load side of the DC / DC converter unit 20-1, and the generation of the load side high voltage can be prevented.

(Effect of Example 1)
According to the first embodiment, the capacitor 41 is connected between the positive power line 14a and the ground GND, and the capacitor 42 is connected between the negative power line 14b and the ground GND. The leakage voltage pulse P2 generated from the DC / DC converter units 20-2 to 20-N in the state flows to the capacitors 41 and 42. Therefore, the voltage generated from the DC / DC converter unit 20-1 in the output off stop state to the load side can be reduced to a level where no electric shock is generated.

  FIG. 4 is a circuit diagram showing a configuration example of each DC / DC converter unit according to the second embodiment of the present invention. Elements common to those in FIG. 2 showing the first embodiment are denoted by common reference numerals. Yes.

  Each DC / DC converter unit 20 of the second embodiment has the same configuration as that of the first embodiment, but instead of the capacitors 41 and 42 of the first embodiment, a third capacitor is provided for each DC / DC converter unit 20. 43 and the fourth capacitor 44 are connected to each other.

The third capacitor 43 is a first positive input terminal 21a in each DC / DC converter unit 20 (that is, the positive power supply line 31g of the switch unit 31 connected to the positive input terminal 21a) and a ground electrode. It is connected to a certain ground GND. Furthermore, the fourth capacitor 44 is connected to the first negative input terminal 21b (that is, the negative power supply line 31h of the switch unit 31 connected to the negative input terminal 21b) in each DC / DC converter unit 20, and the ground. It is connected between the ground GND which is an electrode.
Other configurations are the same as those of the first embodiment.

  According to the second embodiment, when the capacitors 43 and 44 are not provided as in the prior art, as in the first embodiment, when the DC / DC converter units 20-2 to 20-N are in an operating state, the DC / DC converter When the unit 20-1 is in a stopped state and the load 36 becomes a no-load 36a close to infinity, a high voltage is generated at the positive output terminal 35a and the negative output terminal 35b of the DC / DC converter unit 20-1. There are things to do.

  However, in the second embodiment, since the capacitors 43 and 44 are connected to the respective DC / DC converter units 20-1 to 20-N, the DC / DC converter units 20-2 to 20-N in the operating state are connected. The leakage voltage pulse P2 generated from the current flows to the capacitors 43 and 44. Therefore, the voltage generated from the DC / DC converter unit 20-1 in the output off stop state to the load side can be reduced to a level where no electric shock is generated.

  In addition, each DC / DC converter unit 20-2 of the second embodiment is compared with the wiring distance of the power supply lines from the DC / DC converter units 20-2 to 20-N of the first embodiment to the capacitors 41 and 42. Since the wiring distance of the power supply line from ˜20-N to each of the capacitors 43 and 44 is short, the inductance value of the power supply line of the second embodiment is smaller than the inductance value of the power supply line of the first embodiment. Therefore, in the second embodiment, the leakage voltage pulse P2 can flow through the capacitors 43 and 44 faster than in the first embodiment, and the generation of the load side high voltage can be prevented quickly and accurately. Moreover, the leakage voltage pulse P2 generated from each of the DC / DC converter units 20-2 to 20-N in the operating state is connected to each capacitor 43 connected to each of the DC / DC converter units 20-2 to 20-N. , 44 can be promptly flown, so that generation of noise due to leakage voltage pulse P2 can also be prevented.

(Modification)
The present invention is not limited to the first and second embodiments, and various usage forms and modifications are possible. For example, the following forms (a) to (c) are available as usage forms and modifications.

  (A) In the second embodiment, capacitors 43 and 44 are connected for each DC / DC converter unit 20 in place of the capacitors 41 and 42 of the first embodiment, but in addition to the capacitors 41 and 42 of the first embodiment, Thus, the capacitors 43 and 44 of the second embodiment may be connected. Thereby, although the number of parts increases, the effect of Example 1 and Example 2 can be show | played.

  (B) Other circuits may be added to the DC / DC converter unit 20 (= 20-1 to 20-N) of FIGS. 2 and 4 or the circuit configuration may be changed to a circuit configuration other than that illustrated. . For example, the switching element constituting the switch unit 31 is constituted by a transistor other than the NMOSs 31a to 31d, a regenerative diode or the like is connected in parallel to the switching element, or abnormal discharge generated on the load 36 side. In order to prevent this, a reverse bias application circuit may be provided on the output side of each DC / DC converter 30. The DC / DC converter 30 shown in FIGS. 2 and 4 is composed of a flyback type isolated DC / DC converter. However, the DC / DC converter 30 may be changed to another configuration such as a forward type isolated DC / DC converter. Also good.

  (C) Although the multi-output DC sputtering power supply device has been described in the first and second embodiments, the present invention can also be applied to other multi-output power supply devices.

DESCRIPTION OF SYMBOLS 10 DC power supply 11 AC power supply 12 Rectifier circuit 13a 1st positive electrode side output terminal 13b 1st negative electrode side output terminal 20, 20-1-20-N DC / DC converter unit 21a 1st positive electrode side input terminal 21b 1st Negative side input terminal 30 DC / DC converter 31 switch part 32 transformer 33 rectifier part 34, 41, 42, 43, 44 capacitor 35a second positive side output terminal 35b second negative side output terminal 36 load 36a no load

Claims (6)

A common DC power source that outputs the first DC power from the first positive output terminal and the first negative output terminal;
A plurality of DC / DC converter units connected in parallel to the first positive electrode side output terminal and the first negative electrode side output terminal and respectively outputting second DC power to individual loads;
A power supply device comprising:
Each of the DC / DC converter units is
A first positive electrode side input terminal and a first negative electrode side input terminal which are connected to the first positive electrode side output terminal and the first negative electrode side output terminal and input the first DC power;
A DC / DC converter for converting the input first DC power into the second DC power of a predetermined level;
A second positive output terminal and a second negative output terminal for outputting the converted second DC power to the individual load, respectively.
A first capacitor is connected between the first positive output terminal and the ground electrode,
A power supply device, wherein a second capacitor is connected between the first negative output terminal and the ground electrode. A common DC power source that outputs the first DC power from the first positive output terminal and the first negative output terminal;
A plurality of DC / DC converter units connected in parallel to the first positive electrode side output terminal and the first negative electrode side output terminal and respectively outputting second DC power to individual loads;
A power supply device comprising:
Each of the DC / DC converter units is
A first positive electrode side input terminal and a first negative electrode side input terminal which are connected to the first positive electrode side output terminal and the first negative electrode side output terminal and input the first DC power;
A DC / DC converter for converting the input first DC power into the second DC power of a predetermined level;
A second positive output terminal and a second negative output terminal for outputting the converted second DC power to the individual load, respectively.
A third capacitor is connected between each first positive electrode side input terminal and the ground electrode in each DC / DC converter unit,
A power supply device, wherein a fourth capacitor is connected between each first negative electrode side input terminal and each ground electrode in each DC / DC converter unit. A first capacitor is connected between the first positive output terminal and the ground electrode,
The power supply device according to claim 2, wherein a second capacitor is connected between the first negative electrode side output terminal and the ground electrode. The DC power supply is
The power supply device according to any one of claims 1 to 3, further comprising a rectifier circuit that rectifies first AC power and outputs the first DC power. The DC / DC converter is:
A switch unit that switches the input first DC power to second AC power;
A transformer for converting the first voltage in the converted second AC power into the second voltage of the predetermined level;
A rectifying unit that rectifies third AC power having the converted second voltage and outputs the second DC power;
The power supply device according to any one of claims 1 to 4, wherein the power supply device is provided.   The power supply apparatus according to claim 5, wherein a smoothing unit that smoothes output power of the rectifying unit is connected to an output side of the rectifying unit.

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