Pumps – With condition responsive pumped fluid control – Inlet throttle or stop valve
Reexamination Certificate
1999-08-26
2003-08-19
Walberg, Teresa (Department: 3742)
Pumps
With condition responsive pumped fluid control
Inlet throttle or stop valve
C417S423400
Reexamination Certificate
active
06607365
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vacuum pump and a vacuum apparatus, and more specifically to a vacuum pump and a vacuum apparatus capable of controlling a sucking performance for gas within a vacuum container.
2. Description of the Related Art
When a semiconductor or a liquid crystal is manufactured through dry etching, CVD and the like, a vacuum apparatus is employed in which a process gas is introduced into a chamber, and the introduced process gas is sucked and discharged by means of a vacuum pump.
Now,
FIG. 15
shows a turbomolecular pump taken as an example of vacuum pumps conventionally used for such vacuum apparatuses.
As shown in
FIG. 15
, a vacuum pump (turbomolecular pump) is so arranged as follows. Stator blades and rotor blades are axially arranged in a multi-stage manner in a stator section and a rotor section, respectively, which constitute a turbine. The rotor section is rotated at a high speed by a motor, thereby being capable of conducting an exhaustion (vacuum) process from an inlet port shown in an upper portion of the figure to an outlet port shown in a lower left portion of the figure.
FIG. 16
is an explanatory diagram showing an outline of the conventional vacuum apparatus having a chamber equipped with such a vacuum pump.
As shown in
FIG. 16
, the conventional vacuum apparatus is provided with an outlet port on a bottom surface (or a side surface) of a chamber (container)
90
. A process gas received in the chamber
90
may be then sucked and discharged externally of the chamber
90
by means of a vacuum pump
95
through this outlet port. A conductance variable valve
96
having an elongated value is intermediately arranged between the outlet port and the vacuum pump
95
. This conductance variable valve
96
adjusts an amount of the process gas to be sucked and discharged into the vacuum pump
95
, to thereby control a pressure in the chamber
90
to be set within a certain range.
It should be noted that although not shown in this figure, a stage on which a sample and the like are placed is provided in the chamber (container)
90
, while a driving mechanism for rotating the stage and the like is arranged externally of the chamber
90
below the stage.
However, in such a conventional vacuum apparatus, the conductance variable valve
96
is placed to maintain the atmospheric pressure in the chamber
90
within a certain range. This conductance variable valve
96
must adjust an amount of gasses to be sucked by the vacuum pump
95
.
The conductance variable valve
96
is intermediately arranged between the chamber
90
and the vacuum pump
95
, with the result that a vacuum apparatus as a whole becomes larger in size, and requires a large space for installing the apparatus. Besides, there arise such problems in that a manufacturing cost is increased and a time-consuming assembly is required.
In addition, the intervention of the valve between the chamber
90
and the vacuum pump
95
causes a conductance to be deteriorated, which may also affect the exhaustion performance of the vacuum pump
95
. Such problems are also concerned.
SUMMARY OF THE INVENTION
In view of the above, the present invention has been made, and therefore has a primary object of the present invention to provide a vacuum pump capable of controlling a gas sucking performance.
Further, a secondary object of the present invention is to provide a vacuum apparatus requiring a small space for installing the apparatus with less manufacturing cost and less time-consuming assembly.
In order to attain the above-mentioned primary object of the present invention, there is provided a vacuum pump comprising: an inlet port for sucking gas; a gas feeding portion for feeding gas sucked from the inlet port; an outlet port for discharging the gas to an outside fed by the gas feeding portion; a passage area increasing/decreasing mechanism for increasing/decreasing an area of a gas passage, provided at least one place from the inlet port to the outlet port including the gas feeding portion; and a control means for controlling the passage area increasing/decreasing mechanism to increase/decrease the area of the gas passage.
According to the vacuum pump of the present invention, the control of a passage area increasing/decreasing mechanism allows a pressure at an inlet port to be varied, so that a gas sucking performance of the vacuum pump can be controlled.
In order to attain the above-mentioned secondary object of the present invention, there is provided a vacuum apparatus comprising the vacuum pump as described above and a container from which gas received therein is sucked and discharged by the vacuum pump.
In this connection, preferably, the vacuum apparatus further comprises a pressure sensor for outputting a signal corresponding to a pressure within the container, wherein the control means determines an amount to be controlled responding to the output from the pressure sensor.
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Kabasawa Takashi
Nonaka Manabu
Okada Takashi
Adams & Wilks
Fastorsky Leonid
Seiko Seki Kabushiki Kaisha
Walberg Teresa
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