JPH09273659A - Baking device for vacuum device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently remove water sticking to equipment or the like, by providing a gas heating and supply device which heats gas and feed it to a vacuum vessel and an exhaust device which exhausts gas, and alternately repeating gas introduction to the vacuum vessel from the gas heating supply device and gas exhaust. SOLUTION: In the case of baking of a vacuum vessel 1, first by a turbomolecular pump 5, vacuum exhaust is perfumed, also a current is carried in a gas heating device 3, preheating is attained. Next, when a pressure of the vacuum vessel 1 is decreased to a prescribed value, the pump 5 is stopped, valves V1, V2 are opened, a leak valve V3 is gradually opened, heated nitrogen gas is introduced in the vacuum vessel 1. In the point of time the pressure rises in the vicinity of the atmosphere, valves V4, V5 and V3, V2 are successively closed, after inside the vacuum vessel 1 is kept in the atmospheric pressure for a while, an exhaust system is driven, nitrogen gas in the vacuum vessel 1 is exhausted. After this operation is repeated by several number of times, operation is switched to vacuum exhaust by a turbomolecular pump 11, baking is ended.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a baking device for a vacuum device.

[0002]

2. Description of the Related Art In a vacuum device, in order to realize a high vacuum or an ultrahigh vacuum by exhausting the gas inside the vacuum device to reduce the pressure, in addition to increasing the exhaust speed of the vacuum pump, a vacuum container and a vacuum are used. The most important issue is to reduce the gas emission from the components inside the container. When the atmospheric pressure and vacuum evacuation, the exhaust gas of the vacuum container interior in the gas phase readily terminated, 10 ~ ⁵ Torr near-high vacuum after the following pressure water the exhausted emitted from the inner surface It becomes the main component of gas. This water was contained in the atmosphere to which the inside of the vacuum container was exposed before vacuum evacuation, and was adsorbed on the surface of the vacuum container of the vacuum device and the internal components.
The energy that this water adsorbs on the surface of the container and equipment is
It is larger than the adsorption energy of other gas components such as nitrogen contained in the air, and is the most difficult gas to be exhausted during vacuum exhaust from the atmosphere.

Therefore, in order to exhaust the water, baking is performed to heat the entire vacuum container. Usually, a heater is wound around the outer surface of the vacuum container, or a heater jacket is attached to heat the vacuum container. It is performed by the thermal method. Further, as in JP-A-3-106432, there is a method of introducing a temperature-controlled high-temperature nitrogen gas into a vacuum apparatus and heating the inner surface of the vacuum container to desorb gas molecules adsorbed on the inner surface. is there.

[0004]

SUMMARY OF THE INVENTION In the above-mentioned conventional baking method using external heat, a device installed outside the vacuum container, for example, a motor for transmitting rotational movement to the inside of the vacuum,
Baking cannot be performed when there is a device having low heat resistance such as a magnet that generates a magnetic field inside.
Further, there is a problem that it becomes difficult to perform baking when there is no space for installing the heater jacket. Also, in the method of continuously flowing the high-purity nitrogen gas into the vacuum device, a special device for obtaining the high-purity gas is required, and the gas adsorbed on the surface is replaced by the nitrogen gas. Therefore, there was a problem of low efficiency in terms of exhausting water.

An object of the present invention is to obtain a baking method for reducing water adsorbed on the surface and reducing water gas emission from the surface, and a baking apparatus for realizing the same.

[0006]

The above-mentioned object is achieved by introducing heated nitrogen gas or the like into a vacuum container and repeating evacuation, and by a baking device equipped with a heating device and an exhaust device for realizing them. .

According to the present invention, the inside of the vacuum container was contained in the exposed atmosphere before the vacuum exhaust,
Water adsorbed on the surface of the vacuum container of the vacuum device and internal components can be efficiently removed by repeatedly introducing and exhausting the heating gas into the vacuum container, so that gas emission from the inside can be reduced. it can.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a vacuum apparatus and a baking apparatus according to the present invention. Vacuum device is vacuum container 1
And an exhaust port 2 connecting a high vacuum pump 11 for evacuating the vacuum device 1, a roughing pump 12 for exhausting from the high pressure side of the high vacuum pump to atmospheric pressure, a vacuum exhaust system and a vacuum container. And a valve V6 between them.

The following devices are attached to the vacuum device as a baking device. In the gas introduction system, a gas heating device 3 is attached to the vacuum container 1 via a variable leak valve V3 and a stop valve V2. The gas heating device 3 is connected to a gas cylinder 4 serving as a gas supply source via a stop valve V1. Further, a pressure gauge or vacuum gauge 7 and a thermometer 8 are attached to the vacuum container 1. As an exhaust system of the baking apparatus, a turbo molecular pump 4 and a roughing pump 6 capable of exhausting even a high pressure for exhausting a gas used for baking via a stop valve 4 in an exhaust port 2. Are connected. The exhaust system exhaust system controller 9 controls the opening and closing of the valves V4 and V5 by the exhaust system controller 9. Operation control of the heating gas introduction system valves V1 to V3 and the gas heating device 3 is controlled by the baking device controller 10. Further, the baking device controller also controls the controller 9 of the baking device exhaust system which is operated in conjunction with the pressure and temperature data used for control and the gas introduction system.

The baking method of the vacuum apparatus of the present invention will be described. The atmospheric pressure vacuum container 1 is first evacuated by the turbo molecular pump 5 of the baking device exhaust system. During this time, the heater of the gas heating device is turned on to start the residual heat of the heating device. When the pressure in the vacuum container 1 drops to near the ultimate pressure of the turbo molecular pump, the stop valves V1 and V2 are opened and the variable leak valve V3 is gradually opened to introduce heated nitrogen gas into the vacuum container.
At the same time, the operation of the exhaust system pump is stopped. At this time, the valves V4 and V5 are left open. The introduced gas temperature is controlled by the input of power to the gas heating device. The pressure in the container is controlled based on the output of the pressure gauge. When the pressure rises to near atmospheric pressure, valve V4
Close V5. When the inside of the vacuum container 1 becomes atmospheric pressure,
The leak valve V3 and the stop valve V2 are closed to stop the gas supply. The inside of the vacuum container 1 is kept at atmospheric pressure for a while thereafter. After that, the valves V4 and V5 are opened and the exhaust system is operated to exhaust the nitrogen gas in the vacuum container 1. The above operation is automatically controlled by the baking device controller 10. After repeating this operation several times, the pump 11 of the vacuum system exhaust system is switched to vacuum exhaust to complete the baking with the heating gas. When exhausting the vacuum container to atmospheric pressure, the valve 16 may be opened and the vacuum pump 11 may be exhausted at the same time.

The above-mentioned baking treatment has a high efficiency of replacing the water molecules adsorbed inside the vacuum container due to the heating gas, and further, the replacement gas is evacuated a plurality of times, so that the residual water inside the vacuum apparatus is removed. The number of molecules is greatly reduced as compared with the treatment in which nitrogen gas is continuously passed, and a high vacuum can be easily obtained. Further, if the baking device is integrated, the connection and disconnection with the vacuum device can be easily performed, so that the baking device can be removed from the vacuum device at the end of the baking process. For this reason, even when a plurality of vacuum devices are used, if baking is performed at different times, all baking can be performed with one baking device, and the cost required for baking can be greatly reduced. Further, this baking method does not cause thermal damage to the peripherally mounted devices, since there is no external heater or the like around the vacuum device. In addition, workability around the vacuum device is also improved.

FIG. 2 is an example in which a turbo molecular pump is not used as an evacuation system for a baking apparatus and only a roughing pump such as a rotary pump is used. In this example, the ultimate pressure when the gas in the vacuum container is exhausted is high, and the effect of baking with heating gas is small, but depending on the pressure level required by the vacuum device, the turbo molecular pump can be used as in this example. Is unnecessary.

FIG. 3 does not have a baking device exhaust system,
This is a baking device using heated gas. The heating gas is introduced, the nitrogen gas is introduced into the vacuum device, and the replacement gas is released to the outside by utilizing the gas pressure. In this method, since the inside of the vacuum apparatus is always at atmospheric pressure or higher, the efficiency of substituting water molecules is lower than that in the method shown in FIGS. 1 and 2, but baking is possible.

FIG. 4 shows the same baking apparatus system as that of the embodiment shown in FIG.
Is attached. When the vacuum container 1 is evacuated by the turbo molecular pump 5, a pressure that the residual gas analyzer 13 can use is obtained. At that point, the residual gas analyzer is activated and the amount of residual water molecules is measured. Since the progress of baking can be monitored from this measurement data, it is possible to control baking automatically until a certain set value is reached. In order to make the baking device into an integrated device, a pressure gauge, a thermometer, and a residual gas analyzer may be installed directly above the turbo molecular pump.

In the above embodiments, nitrogen gas is used as the heating gas, but nitrogen gas such as argon, air, etc. can also be used. It is also possible to supply air by using a dry compressor equipped with a high-performance oil filter without using an air cylinder.

[0017]

According to the present invention, the inside of the vacuum container was contained in the atmosphere to which the interior of the vacuum container was exposed before the vacuum evacuation, and it was adsorbed on the surface of the vacuum container of the vacuum device and the internal components. The water can be efficiently removed by repeatedly introducing and exhausting the heating gas into the vacuum container, so that the gas emission from the inside can be reduced.

As a result of the above, a high vacuum can be obtained with a vacuum apparatus by a simple method and apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment showing a baking apparatus of the present invention.

FIG. 2 is a block diagram in which only a roughing pump is used in a baking exhaust system.

FIG. 3 is a block diagram of an embodiment of the present invention that does not use a baking exhaust system.

FIG. 4 is a block diagram showing an example of using residual gas analysis data for baking control.

[Explanation of symbols]

1 ... Vacuum container, 2 ... Exhaust port, 3 ... Gas heating device, 4
… Gas cylinders 5,11… Turbo molecular pumps 6,12
... roughing pump, 7 ... pressure gauge, 8 ... thermometer, 9 ... baking device exhaust system controller, 10 ... baking device controller.

Claims (1)

[Claims] 1. A gas heating supply device for heating a gas to introduce the gas into a vacuum container, an exhaust device for exhausting the gas, and a control device for controlling the operation of the gas heating supply device and the exhaust device, A baking device for a vacuum device, characterized in that gas introduction from the gas heating and supplying device to the vacuum container and gas exhaust are alternately repeated.