JPS6062050A - Sputter ion pump power supply - Google Patents

Abstract

PURPOSE:To enable a sputter ion pump power supply to operate safely regardless of its output load by detecting spark discharge. CONSTITUTION:A d.c. voltage relay 7 has the function of inactivating a switching circuit 2. A switch 8 has the function of inactivating the d.c. voltage relay 7. A signal detector 11 has the function of inactivating the switching circuit 2 by utilizing pulse signals detected by a current transformer 10. When continuous spark discharge develops, the output voltage of a high-voltage contact plug 9 has the wave form (a); the voltage (VB) is a voltage necessary for initiating the electric discharge of a dielectric breakdown part. The output current produced at this point has a pulse-like wavy form and is detected with the current transformer 10. In contrast, during the normal electric discharge, a d.c. current flows and the current transformer 10 is inactivated. The current having a pulse-like wavy form and detected with the current transformer 10 is then converted into a d.c. voltage by means of the signal detector 11. The thus produced d.c. voltage drives the relay and the like of the signal detector 11 to inactivate the switching circuit 2 thereby cutting off a commercial input power supply 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power source for an ion pump used for evacuating the inside of a vacuum container.

The well-known subac ion pump bombards a cathode surface made of an active metal with ions created by a Benign discharge, causing active metal atoms to sputter from the cathode onto the surrounding walls. This sputtered film allows the active gas to
It is also a type of duck ion pump that depletes rare gas by trapping ions on a part of the cathode surface.

The output voltage and current characteristics required for an ion pump power supply are low voltage and large current for low vacuum loads, and high voltage and small current for high vacuum loads. It requires zero times the current compared to the drooping characteristics of the transformer. Therefore, in S-, O-, and +97-type power supplies, the transformer for the commercial frequency power supply is replaced with a leakage transformer, and the rectifier circuit is further devised to provide sufficient power supply with low vacuum loads. Also, since the load of the IJJ blade part of the Snow Etta Ion Bonozo power supply becomes a discharge load,
Output 4 is provided to the output section for the purpose of pressure stabilization and protection in the event of an output short circuit.

Insert the output resistor. Furthermore, the line 51 is directly connected to the discharge return line.
An overcurrent protection circuit is constructed by inserting a v voltage relay and turning off the power when an overcurrent flows.

FIG. 1 is a block diagram showing a schematic configuration of a conventional suction pump power source. In Figure 1, ■ is an input commercial power supply, 2 is a switch circuit, 3 is a leakage transformer, 4 is a rectifier circuit, 5 is a rectifier capacitor, 6 is an output resistor, 7 is a DC voltage relay, 8 is a switch, 9 is a high voltage output plug.

Since the voltage across the rectifying capacitor 5 decreases as the load current increases, the power applied to the output resistor 6 is small even if the output is short-circuited, and the power capacity of the output resistor 6 is small when the load is normally discharged. Sometimes you just have to use what you can afford.

In addition, the overcurrent protection circuit consisting of the DC voltage ITI IJ layer and switch circuit 2 will heat up the mains ion pump if used for a long time in the glow discharge area.

It is desirable that the device operate in the nick discharge region. However, since the sputter ion pump power source is used for the purpose of extracting air from the inside of a vacuum container, it is generally started to operate at a low vacuum load, that is, in a glow discharge region. Therefore, by short-circuiting (closing) the switch 8 connected in parallel with the DC voltage relay 7, the power supply to the DC voltage relay 7 is stopped, the overcurrent protection function is canceled, and the drive is started. do.

However, when this switch 8 is short-circuited, it is a problem.

If there is a high vacuum load inside the tie ion pump, for example, the high voltage output connector 9 of the power supply or the sputter ion pump connector (
(not shown), dielectric breakdown may occur due to continuous spark discharge such as 5th order. That is, in the rectifying It'l capacitor 5, the discharge start 711i of the dielectric breakdown part,
The electric charge is charged until the voltage reaches a voltage that is almost the highest, resulting in a spark discharge, and then the electric charge is charged again into the rectifying +11 capacitor 5, and the spark discharge continues until the discharge start voltage is reached again, and a spark discharge occurs again.

If a continuous spark discharge occurs as described above, the output resistor 6
Excessive power is consumed, and the amount of power consumed at that time varies depending on the output capacity of the leaky transformer 3, the discharge resistance of the vacuum load, the discharge resistance of the spark discharge, and the capacity of the rectifying capacitor 5. There is a possibility that the heat generated by the output resistor 6 may damage the power supply. In addition, the above phenomenon also occurs when the overcurrent protection function is released and the vacuum load is close to atmospheric pressure, causing the power supply to run out in the same manner as described above. There is a risk of melting the internal electrodes.

The purpose of the present invention is to detect and detect spark discharge, which has not been detected in the past. The horn power supply is designed to operate safely no matter what the output load is.
The goal is to provide a source of gummies.

According to the invention, S.ξtutaion 71? Means for selectively detecting the difference in current waveform between glow discharge or nicked discharge, which is normal discharge, and spark discharge, which is abnormal discharge, in the load of the pump 0' source, and the output of this detection means is used to connect the sputter ion pump power A sputter ion 2Y power source is obtained which is characterized by providing a means of protection against abnormal discharge that causes a 1μ scratch.

That is, 9 the present inventors, S.e., Qion Moon? Of the discharge currents that flow through the battery, the discharge currents of glow discharge and Penning discharge, which are normal discharge currents, are almost direct current,
Snow 9 Tsukuio y, l = nfu 0 power source ya suo hno”
-, 7''Q ・7-J l/r upper g, m or l; I noticed J in 1B where the discharge current of the spark discharge that is Wojinkaido Ii & lightning becomes a ・ξ lasing current. Therefore, in the present invention, a transformer or the like is used to 1) detect only the IJ pulsed 7E flow, and perform a process Uσ such as stopping the sputter ion and +Ij power supplies to drive it safely.

The present invention provides two types of protection functions against spark discharge of the output load. However, the present invention will be explained in detail below using the drawings.

FIG. 2 shows 5 sputtered ions according to the present invention 7]? FIG. 1 is a block diagram showing a schematic configuration of an embodiment of Nzoden Detachment. Second
In the figure, ■ is a human-powered commercial power supply, 2 is a switch circuit, and 3 is a switch circuit.
is a leaky transformer, and 4 is a rectifier circuit.

5 is a rectifying capacitor, 6 is an output, 1 is a resistor 2, 7 is an iQ current voltage relay and has the function of disabling the switch circuit 2. 8 is a switch and is a DC 11) 1 voltage relay 7
It has the function of making it immobile. 9) Two high voltage output connectors,
10 is a current transformer that detects only the stray signal.

Reference numeral 11 denotes a signal detector which has a function of disabling the switch circuit 2 by using the signal generated by the current transformer 10.

Due to the above tilt configuration, when the above-described continuous spark discharge occurs, the output voltage at the high voltage output plug 9 and the output current have the waveform shown in FIG. 3 (b).

detected by current transformer 10. On the other hand, in the case of normal discharge, a direct current flows, so the current transformer 10 becomes inactive.

? of the waveform detected by the current transformer 10? li
The current is converted into a DC voltage by the signal detector 11, which drives a relay or the like of the signal detector 11 to disable the switch circuit 2 and cut off the input commercial power source 1.

Although the second embodiment uses a current transformer to detect pulse current, it is clear that the present invention extends to other methods for detecting pulse current.

Therefore, 1 or more does not have any limiting meaning, and many variations are possible.

As described above, according to the present invention, the spark discharge that easily damages the conventional sputter ion pump power supply and sputter ion pump can be prevented by a safe spark discharge that does not impair the conventional functions.
Guttai ion pump power can be obtained.

[Brief explanation of drawings]

Figure 1 shows the conventional Su-gutsutaion, I? Outline of power supply 4. FIG. 2 is a block diagram showing the outline and general configuration of an embodiment of the sputter ion pump power supply according to the present invention. FIG. 3 is a waveform of output voltage and current during continuous spark discharge. It is a diagram. ■...Input commercial power supply, 2...Switch circuit, 3...
1@Leaky transformer, 4... Rectifier circuit, 5... Rectifier capacitor. 6... Output resistor, 7... DC voltage relay, 8...
...Switch, 9...High voltage output connector, 10...Current transformer. 11...Signal detector.

Claims (1)

[Claims] ■, Sie Means for selectively detecting the difference in current waveform between normal discharge such as glow discharge or nicked discharge and abnormal discharge in spark discharge in the load of a ion pump power supply; A sputter ion pump power supply characterized by comprising means for protecting against the abnormal discharge which damages the ion pump power supply due to the output of the means. 2. The sputter ion pump power supply according to claim 1, wherein the detection means is a transformer that detects only a pulsed current flowing during a spark discharge, which is the abnormal discharge.