JP2003149285A - Test loading apparatus for glow discharge load - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a test loading apparatus capable of checking required functions with a single DC power source, without combining with an apparatus utilizing the glow discharge. SOLUTION: The apparatus comprises a capacitor load 11 for simulating the transition from a high impedance state at a glow discharge caused by feeding a pulse signal to a thyristor switch 1A connected in series to a simulation load 11 having an impedance corresponding to a normal glow, to an impedance state for the normal glow discharge to simulate a voltage corresponding to an arc discharge voltage, and a thyristor switch 18 connected in series to the load 11. After applying a voltage corresponding to an arc discharge voltage to the capacitor load, the thyristor switch is turned on to simulate the transition to a low voltage and low impedance state at arc discharge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power source used in an apparatus using glow discharge such as a sputtering apparatus, in a high impedance state until the start of glow discharge, an impedance state of normal glow discharge, and further arc discharge. The present invention relates to a test load device that simulates a low impedance state at the time of occurrence so that the characteristics of each state of a DC power supply can be easily tested.

[0002]

2. Description of the Related Art In describing a test load device of the present invention, functions required for a DC power source used in a device utilizing glow discharge such as a sputtering device will be described.

FIG. 1 shows current-voltage characteristics of glow discharge. In order for glow discharge to start, a voltage higher than the discharge start voltage must be applied, and when a voltage higher than the discharge start voltage is applied, glow discharge starts and the voltage drops rapidly as the current density increases. Enter the area called Glow in the first half. When the current density further increases, it enters a region called normal glow where the voltage does not change much. Then, when the current density further increases, the voltage also rises into the abnormal glow region, and finally reaches the arc discharge region.

In the case of a sputtering apparatus, the discharge starting voltage is 1000V to 1600V, and the normal glow voltage is several hundreds of volts. On the other hand, during arc discharge, 10
The voltage becomes 0 V or less, and an excessive current flows. This excessive current damages the target material of the sputtering apparatus and also affects the products manufactured by the sputtering apparatus, resulting in the deterioration of the product quality and the yield.

Therefore, as a function of a direct current power source used in a sputtering device using this glow discharge,
(1) At the start of discharge, a voltage higher than the discharge start voltage can be output, and the output impedance at that time is large,
(2) When the glow discharge is started and the steady operation is started, the output impedance is as small as possible, and the voltage is promptly reduced after the glow discharge is started to prevent the abnormal glow region from entering. 3) When arc discharge occurs, the arc discharge is promptly detected and the output voltage is zero V.
Alternatively, a small reverse voltage is required to extinguish the arc discharge, and after a certain period of time, it is output again to restore normal glow discharge.

FIG. 2 shows an example of an output voltage and an output current when an arc discharge occurs in a DC power source for a sputtering apparatus having such a function. When arc discharge occurs, the output voltage drops in steps, and conversely the output current sharply increases. This time is at most tens of ns. After that, when the DC power supply detects arc discharge and the output voltage is set to zero V, the output current is attenuated to zero. The time from when the arc discharge is detected until the output current becomes zero is several μs to several tens μs, though it depends on the DC power supply. When the DC power supply restores the output voltage after a certain period of time, it rises toward the discharge start voltage, and when it exceeds the discharge start voltage, current starts to flow and the voltage also returns to the voltage of the normal glow.

[0007]

However, in the above-mentioned DC power supply, in order to carry out a test for confirming these functions, it has conventionally been necessary to combine with a device itself utilizing glow discharge such as a sputtering device. On the other hand, these devices are expensive, large in size, and cannot be prepared by the manufacturer of the DC power supply, so that the function confirmation test of the DC power supply is difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a test load device capable of confirming the above function with a DC power source alone without combining with a device utilizing glow discharge such as a sputtering device.

[0009]

The test load device of the present invention corresponds to a normal glow by detecting that the voltage corresponding to the glow discharge starting voltage has been reached by a voltage divider and a trigger diode to generate a pulse signal. By supplying a pulse signal to a thyristor switch connected in series to a simulated load with impedance to ignite the thyristor switch, the transition phenomenon from the high impedance state up to glow discharge to the normal glow discharge impedance state can be simulated. It has a function.

Further, the test load device of the present invention comprises a capacitor load simulating a voltage corresponding to the arc discharge voltage and a thyristor switch connected in series to the capacitor load, and the capacitor load corresponds to the arc discharge voltage in advance. By charging the voltage to be charged and then igniting the thyristor switch, it is possible to simulate the transition phenomenon to the low voltage and low impedance state when arc discharge occurs.

Further, the test load device of the present invention comprises an impedance load corresponding to a low impedance state at the time of arc discharge in place of the capacitor load, and a thyristor switch connected in series to this impedance load. By igniting, it has a function that can simulate the phenomenon of transition to the impedance state when arc discharge occurs.

Furthermore, the test load device of the present invention has the function of simulating the transition phenomenon from the high impedance state until the early glow discharge to the impedance state of the normal glow discharge, and the low voltage and low impedance state when arc discharge occurs. With the function to simulate the transition phenomenon to
It also has a function that allows continuous confirmation.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows an example of a circuit of a test load device according to the present invention. This test load device
Discharge start operation simulation circuit 20 and arc discharge simulation circuit 30
It has and.

The discharge start operation simulation circuit 20 includes a thyristor switch 1A, a gate filter 2A thereof, a pulse transformer 3A, a current limiting resistor 4, a trigger diode 5 which turns on at a set voltage or more, and a pulse power supply capacitor 6.
And a voltage divider 7 and a load resistor 8. The load resistance 8 is set to an impedance corresponding to the normal glow region and constitutes a simulated load.

On the other hand, the arc discharge simulation circuit 30 includes a thyristor switch 1B, its gate filter 2B, a pulse transformer 3B, a pulse conversion circuit 9, a gate pulse supply DC power supply 10, and a simulated arc discharge voltage charge. The capacitor 11, the current limiting resistor 12, the block diodes 13 and 14, the DC power supply 15 for charging the simulated arc discharge voltage, the switches 16, 17 and 18, and the switch controller 19.

The test load device having the above-mentioned configuration is connected to the series power source 40 having the above-mentioned function.

Next, the operation of this test load device will be described. First, the simulation operation of the transition phenomenon from the high impedance state until glow discharge to the normal glow discharge impedance state by the discharge start operation simulation circuit 20 will be described. To do.

When the output voltage from the DC power supply 40 is supplied to the test load device, the trigger diode 5 is turned on when the voltage divided by the voltage divider 7 reaches the set voltage of the trigger diode 5 or more. A pulse current determined by the pulse power supply capacitor 6 and the current limiting resistor 4 flows through the pulse transformer 3A. This pulse current is applied to the pulse transformer 3
It is converted to the secondary side of A, the noise is removed by the gate filter 2A, the noise is supplied to the gate of the thyristor switch 1A, and the thyristor switch 1A is turned on. When the thyristor switch 1A is turned on, a current starts to flow in the simulated load 8, but since the simulated load 8 is set to have an impedance corresponding to the normal glow region, it is detected that the DC power supply 40 has entered the glow discharge region. If you reduce the output voltage,
It is possible to enter a steady operation state without overcurrent.

Next, the simulation operation of the transition phenomenon to the low voltage and low impedance state at the time of occurrence of arc discharge by the arc discharge simulation circuit 30 will be described with reference to the switches 16, 17 shown in FIG.
A description will be given with reference to a timing chart of turning on and off of 18.

When the switch 16 is turned on, the capacitor 11 for charging the simulated arc discharge voltage is discharged through the current limiting resistor 12. Next, when the switch 16 is turned off and the switch 17 is turned on, the capacitor 11 for charging the simulated arc discharge voltage is charged via the current limiting resistor 12 by the DC power supply 15 which is set to the simulated arc discharge voltage in advance. Will be charged. After that, when the switch 17 is turned off and the switch 18 is turned on, the gate pulse supply D
A pulse current flows from the C power source 10 to the pulse transformer 3B via the pulse conversion circuit 9. This pulse current is converted to the secondary side of the pulse transformer 3B, and the gate filter 2B
By this, noise is removed and supplied to the gate of the thyristor switch 1B, and the thyristor switch 1B is turned on.
When the thyristor switch 1B is turned on, the current flowing in the simulated load 8 of the discharge start operation simulation circuit 20 is blocked by the block diode 13 because the voltage of the capacitor 11 for charging the simulated arc discharge voltage is low, and the thyristor switch At the same time as 1A is turned off, a current rapidly flows into the capacitor 11 for charging the simulated arc discharge voltage.
At this time, when the DC power supply 40 detects a sudden drop in voltage or an excessive current and detects it as arc discharge and makes the output voltage zero V or generates a small reverse voltage, the output current rapidly decreases. The thyristor switch 1B turns off.

When the DC power supply 40 restores the output voltage after a certain period of time, it rises toward the discharge start voltage, and the discharge start operation simulation circuit 20 operates again.

If the operations of the switches 16, 17 and 18 are not stopped, the operation of the arc discharge simulation circuit 30 is repeated. Therefore, the operation at the time of starting the discharge of the DC power supply and the operation at the time of the arc discharge occurrence can be continuously simulated, and the function can be confirmed.

FIG. 5 shows another circuit example of the test load device according to the present invention. This test load device includes a discharge start operation simulation circuit 20 and an arc discharge simulation circuit 32. The structure of the arc discharge simulation circuit is different from that of the test load device of FIG. That is, the arc discharge simulation circuit 32 is a preliminary charging circuit (block diode 14, DC power supply 1) for the capacitor 11 for charging the simulated arc voltage.
5, there is no switch 16, 17), in other words, it corresponds to the case where the arc voltage is 0V. In this case, the current limiting resistor 12 has a discharge time constant set to a value sufficiently smaller than the on / off cycle of the switch 18. Further, as the switch controller 19, unlike the case of FIG. 3, a single-shot pulse generator having a constant frequency is sufficient.

FIG. 6 shows still another circuit example of the test load device according to the present invention. This test load device includes a discharge start operation simulation circuit 20 and an arc discharge simulation circuit 32. The structure of the discharge start operation simulation circuit is different from that of the test load device of FIG. That is, the auxiliary thyristor 1C is added.

In the discharge start simulating circuit 22, when the trigger diode 5 is turned on, a sufficient current cannot be supplied to turn on the thyristor switch 1A (for example, the thyristor switch 1A has two or more thyristor elements connected in series). When the trigger diode 5 is turned on, the auxiliary thyristor 1C is turned on, and the current flowing through the auxiliary thyristor 1C drives the pulse transformer 3A to supply the gate current of the thyristor switch 1A. Is.

[0026]

As described above, by using the glow discharge load simulation test apparatus of the present invention, the operating characteristics and the arc at the start of discharge of the DC power source used in an apparatus utilizing glow discharge such as a sputtering apparatus. The operating characteristics when a discharge occurs can be easily confirmed without combining with an actual load device, and a single test of the DC power supply becomes possible.

[Brief description of drawings]

FIG. 1 is a diagram showing power-voltage characteristics of glow discharge.

FIG. 2 is a diagram showing an example of an output voltage and an output current when an arc discharge occurs in a DC power supply for a sputtering apparatus.

FIG. 3 is a diagram showing a circuit example of a test load device of the present invention.

FIG. 4 is a timing diagram of switch on / off.

FIG. 5 is a diagram showing another circuit example of the test load device of the present invention.

FIG. 6 is a diagram showing still another circuit example of the test load device of the present invention.

[Explanation of symbols]

1A, 1B thyristor switch 1C auxiliary thyristor 2A, 2B gate filter 3A, 3B pulse transformer 4A, 12 Current limiting resistor 5 Trigger diode 6 Pulse power supply capacitor 7 voltage divider 8 load resistance 9 pulse conversion circuit 10 DC power supply for gate pulse supply 11 Simulated arc discharge voltage charging capacitor 13, 14 Block diode 15 DC power source for charging simulated arc discharge voltage 16,17,18 switch 19 Switch controller 20,22 Discharge start operation simulation circuit 30, 32 arc discharge simulation circuit 40 series power supply

Claims (10)

[Claims] 1. A test load device for a DC power source used in a device using glow discharge, a simulated load having an impedance corresponding to a normal glow, a switch connected in series to the simulated circuit, and a glow discharge starting voltage. And a circuit that creates a pulse signal that turns on the switch by detecting that the voltage has reached a voltage corresponding to, and by turning on the switch by supplying the pulse signal, a high impedance state until glow discharge is obtained. A test load device characterized by simulating a transition phenomenon from a normal glow discharge to an impedance state. 2. The test load device according to claim 1, wherein the simulated load is a resistance and the switch is a thyristor. 3. A test load device for a DC power source used in a device using glow discharge, comprising: a capacitor load simulating a voltage corresponding to an arc discharge voltage; and a switch connected in series to the capacitor. A test load device characterized by simulating a transition phenomenon to a low voltage, low impedance state when an arc discharge occurs by charging a voltage corresponding to the arc discharge voltage in advance and then turning on the switch. 4. A test load device for a DC power source used in a device using glow discharge, comprising: a resistance load corresponding to a low impedance state during arc discharge; and a switch connected in series to the resistance load. A test load device characterized by simulating a transition phenomenon to a low impedance state when an arc discharge occurs by turning on a switch. 5. The test load device according to claim 3, wherein the switch is a thyristor. 6. A test load device for a DC power source used in a device using glow discharge, a simulated load having an impedance corresponding to a normal glow, and a first switch connected in series to the simulated circuit.
A circuit for detecting a voltage corresponding to a glow discharge starting voltage to generate a pulse signal for turning on the first switch, and supplying the pulse signal to supply the pulse signal to the first switch.
By turning on the switch of, the discharge start operation simulation circuit that simulates the transition phenomenon from the high impedance state until glow discharge to the impedance state of normal glow discharge, the capacitor load that simulates the voltage equivalent to the arc discharge voltage, A second switch connected in series to the capacitor, wherein the capacitor is charged with a voltage corresponding to an arc discharge voltage in advance, and then the second switch is turned on to reduce a low voltage when an arc discharge occurs, It has an arc discharge simulation circuit that simulates the transition phenomenon to a low impedance state, transition phenomenon from high impedance state until glow discharge to impedance state of normal glow discharge, and low voltage and low impedance state when arc discharge occurs. A test load device characterized by continuously simulating the transition phenomenon to. 7. The test load device according to claim 6, wherein the simulated load is a resistance, and the first and second switches are thyristors. 8. A test load device for a DC power source used in a device using glow discharge, a simulated load having an impedance corresponding to a normal glow, and a first switch connected in series to the simulated circuit.
A circuit for detecting a voltage corresponding to a glow discharge starting voltage to generate a pulse signal for turning on the first switch, and supplying the pulse signal to supply the pulse signal to the first switch.
By turning on the switch of, the discharge start operation simulation circuit that simulates the transition phenomenon from the high impedance state until glow discharge to the impedance state of normal glow discharge, and the resistive load equivalent to the low impedance state during arc discharge, A second switch connected in series to the resistive load, and turning on the second switch,
It has an arc discharge simulation circuit that simulates the transition phenomenon to the low impedance state when arc discharge occurs, and the transition phenomenon from the high impedance state until glow discharge to the impedance state of normal glow discharge and the low phenomenon when arc discharge occurs. A test load device characterized by continuously simulating a transition phenomenon to an impedance state. 9. The test load device according to claim 8, wherein the simulated load is a resistance, and the first and second switches are thyristors. 10. The test load device according to claim 1, wherein the device utilizing the glow discharge is a sputtering device.