TW201930730A - Turbomolecular pump - Google Patents

Abstract

The prevent invention provides a turbomolecular pump which includes an outer casing, a rotor element, a stator element, and a reinforcement structure. The outer casing has a chamber. The rotor element and the stator element are arranged in the chamber, and the rotor element can rotate relative to the stator element. The rotor element includes a seat body and a plurality of rotor blades connected to the seat body, and the stator element includes a plurality of stator blades which are alternately arranged with the rotor blades. The reinforcement structure is arranged on the seat body and away from the rotor blades and the stator blades. Whereby, the turbomolecular pump can have an increased operating life.

Description

Turbo molecular pump

The invention relates to a turbo molecular pump, and in particular to a turbo molecular pump with improved rotor structure.

With the rapid development of semiconductor process technology, the role of semiconductor process equipment has become more and more important, and the pumping efficiency of the heart-turbo molecule pump of the vacuum system has gradually received attention. The turbo molecular pump is driven by a high speed rotation of the rotor relative to the stator to discharge the gas in the processing chamber (or cavity) of the semiconductor processing equipment to achieve the vacuuming effect.

However, when a turbo molecular pump is applied to an etching apparatus, a large amount of particles generated during the etching process are usually accumulated on the exhaust port and the rotor, causing a problem that the exhaust efficiency is lowered and the vacuum cannot be evacuated. In order to slow down the formation of deposits, the conventional turbo molecular pump is mostly heated to increase the temperature of each component, and the adhesion of the particles can be suppressed. However, the rotor of the existing turbo molecular pump is generally made of aluminum alloy, and the temperature at which the aluminum alloy can maintain the crystallization stability is about 100 ° C or less. As long as the ambient temperature is higher than 100 ° C or even reaches the aging temperature of the aluminum alloy, the aluminum alloy is Will begin to produce crystallization precipitation reaction; once the turbo molecular pump is operated in a high temperature environment for a period of time, the structure of the rotor will lead to irreversible weakening of the strength, in which case the expansion deformation of the rotor will be more serious. It will cause fatigue cracking of the rotor.

The technical problem to be solved by the present invention is to provide a turbo molecular pump that can operate stably and reliably in a high temperature environment in view of the deficiencies of the prior art.

In order to solve the above technical problem, one of the technical solutions adopted by the present invention Yes: A turbomolecular pump that includes a housing, a stator element, a rotor element, and a reinforced structure. The housing has a cavity; the stator element is disposed in the cavity, wherein the stator element includes a plurality of fixed wings; the rotor element is disposed in the cavity and has a rotation relative to the stator element Degree of freedom, wherein the rotor element includes a rotor seat and a plurality of rotating wings disposed on the rotor seat, and a plurality of the rotating blades are alternately arranged with the plurality of fixed wings; and the reinforcing structure is disposed on The rotor base is disposed on the plurality of the rotating blades and the covered areas of the plurality of fixed wings.

In an embodiment of the present invention, the two ends of the outer casing respectively have an air inlet and an air outlet connected to the cavity, the rotor base includes a first seat body and a a second seat body extending from an end of the body, the first seat body being adjacent to the air inlet, the second seat body being adjacent to the air exhaust port, and outside the first seat body The diameter is smaller than the outer diameter of the second seat body, wherein a plurality of the rotary wings are coupled to the first seat body.

In an embodiment of the invention, the reinforcing structure is disposed on the second seat.

In an embodiment of the invention, the second seat body has a front end portion and a rear end portion extending from an end of the front end portion, the rear end portion being closer to the row than the front end portion a port, and a thickness of the rear end portion is smaller than a thickness of the front end portion, wherein the reinforcing structure is disposed around the rear end portion.

In an embodiment of the invention, the front end portion has a thickness h, and the rear end portion has a thickness greater than 2/3h but less than h.

In an embodiment of the invention, the rotor element further includes a high speed main shaft, and the high speed main shaft is disposed in the rotor seat, wherein the front end portion has an inner peripheral wall and a inner peripheral wall a peripheral wall, and the inner peripheral wall is closer to the high speed main shaft than the outer peripheral wall, wherein the reinforcing structure has an outer surface, and the outer surface is flush with the outer peripheral wall.

In an embodiment of the invention, the reinforcing structure is a ring structure, and The material of the reinforcing structure is titanium alloy or carbon fiber.

In an embodiment of the invention, the turbo molecular pump further includes a power base for assembling the outer casing, the stator element and the rotor element, wherein the power base has a bearing mechanism The bearing mechanism is disposed between the rotor seat and the high speed main shaft for driving the rotor element through the high speed main shaft.

In an embodiment of the invention, the turbo molecular pump further includes a heating device, and the heating device is disposed around the power base.

In an embodiment of the invention, the cavity is a vacuum chamber.

In an embodiment of the invention, each of the fixed wings includes a plurality of stator blades, each of which includes a plurality of rotor blades.

One of the beneficial effects of the present invention is that the turbo molecular pump provided by the present invention can be provided with a "reinforcing structure disposed on the rotor seat and avoiding the coverage areas of the plurality of rotating blades and the plurality of fixed wings". Under the premise of not affecting all the high-speed dynamic characteristics and vacuuming efficiency of the rotor element, the fragile point of the fatigue deformation of the rotor component in the high temperature environment is avoided, thereby effectively extending the service life of the pump.

For a better understanding of the features and technical aspects of the present invention, reference should be made to the detailed description and drawings of the invention.

P‧‧‧ Turbo Molecular Pump

1‧‧‧Shell

11‧‧‧ cavity

12‧‧‧air inlet

13‧‧‧Exhaust port

W1‧‧‧ inner wall

2‧‧‧Rotor components

21‧‧‧ rotor seat

211‧‧‧ first body

212‧‧‧Second body

2121‧‧‧ front end

2122‧‧‧ Back end

D1, D2‧‧‧ thickness

22‧‧‧Rotating Wings

221‧‧‧Rotor blades

23‧‧‧High speed spindle

W21, W23‧‧‧ peripheral wall

W22‧‧‧ inner wall

3‧‧‧stator elements

31‧‧‧Fixed Wing

311‧‧‧ stator blades

32‧‧‧ Stator ring

4‧‧‧Enhanced structure

41‧‧‧First strengthening layer

42‧‧‧Second reinforcement

5‧‧‧Power base

51‧‧‧ bearing mechanism

6‧‧‧ heating device

G‧‧‧ gas molecules

1 is a perspective view of a turbo molecular pump according to an embodiment of the present invention.

2 is an exploded perspective view of a turbo molecular pump according to an embodiment of the present invention.

Figure 3 is a cross-sectional view taken along line III-III of Figure 1.

Figure 4 is a partial enlarged view of a portion IV of Figure 3.

FIG. 5 is a perspective view of a rotor element and a stator element in a turbo molecular pump according to an embodiment of the present invention.

Figure 6 is a plan view of a rotor element in a turbo molecular pump in accordance with one embodiment of the present invention.

FIG. 7 is a schematic diagram showing the principle of operation of a turbo molecular pump according to an embodiment of the present invention; Figure.

Figure 8 is another partial enlarged view of the portion IV of Figure 3.

9 is a perspective view of a rotor element and a stator element in a turbo molecular pump according to another embodiment of the present invention.

The following is a description of an embodiment of the present invention relating to a "turbo molecular pump" by a specific embodiment, and those skilled in the art can understand the advantages and effects of the present invention from the disclosure of the present specification. The invention can be implemented or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention. In addition, the drawings of the present invention are merely illustrative and are not intended to be stated in the actual size. The following embodiments will further explain the related technical content of the present invention, but the disclosure is not intended to limit the scope of the present invention.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements or signals, these elements or signals are not limited by these terms. These terms are primarily used to distinguish one element from another, or one signal and another. In addition, the term "or" as used herein may include a combination of any one or more of the associated listed items, depending on the actual situation.

[First Embodiment]

Referring to FIG. 1 to FIG. 3, a first embodiment of the present invention provides a maglev type turbo molecular pump P, which mainly includes an outer casing 1, a rotor element 2, a certain sub-element 3, a reinforcing structure 4, and a power. Base 5. The housing 1 has a cavity 11 in which the rotor element 2 and the stator element 3 are both disposed, and the rotor element 2 has a rotational freedom with respect to the stator element 3. The rotor element 2 includes a rotor seat 21 and a plurality of rotating wings 22 connected to the rotor seat 21. The stator element 3 includes a plurality of fixed wings 31 connected to the outer casing 1, and the plurality of rotating wings 22 are alternately arranged with the plurality of fixed wings 31. Form a tight cross-matching combination. The reinforcing structure 4 is disposed on the rotor seat 21 and avoids The rotating wing 22 and the covered area of the fixed wing 31. The power base 5 is for assembling the outer casing 1, the rotor element 2 and the stator element 3, and drives the rotor element 2 to rotate at a high speed.

Specifically, the material of the outer casing 1 may be stainless steel, but is not limited thereto; the outer casing 1 has a cylindrical shape to form a cavity 11 in a surrounding structure, wherein both ends of the outer casing 1 are open ends, that is, the outer casing 1 The two ends have an air inlet 12 and an air outlet 13 respectively communicating with the cavity 11.

The material of the rotor element 2 may be a high-strength aluminum alloy, but is not limited thereto; the rotor element 2 is rotated at a high speed by a high-speed spindle 23, and the high-speed spindle 23 is disposed in the rotor seat 21, and one end of the high-speed spindle 23 passes. A connector (not shown) is attached to the rotor base 21. Further, the rotor base 21 includes a first base 211 and a second base 212 extending from the end of the first base 211. The first base 211 is adjacent to the air inlet 12, and the second base 212 is adjacent to the second base 212. The first seat body 211 and the second seat body 212 are both cylindrical, and the outer diameter of the first seat body 211 is smaller than the outer diameter of the second seat body 212. The plurality of rotating blades 22 are integrally formed with the first and second seats 211, 212, wherein the plurality of rotating blades 22 are connected to the outer peripheral wall W21 of the first seat 211 and are vertically layered, and the plurality of rotating wings 22 are The extending direction is substantially perpendicular to the extending direction of the first and second seats 211, 212, that is, the plurality of rotating wings 22 extend radially outward, and the first and second seats 211, 212 are axially Extend backwards.

The material of the stator element 3 may be a high-strength aluminum alloy, but is not limited thereto; the plurality of fixed wings 31 are connected to the inner peripheral wall W1 of the outer casing 1 and are vertically layered, wherein the plurality of fixed wings 31 extend in a direction The extending directions of the rotary blades 22 are substantially parallel, that is, the plurality of fixed wings 31 extend radially inward. In the present embodiment, the plurality of fixed wings 31 are connected to the inner peripheral wall W1 of the outer casing 1 by the stator shroud 32, but are not limited thereto.

Referring to FIGS. 5 to 7, in the present embodiment, the rotor element 2 includes eight rotor blades 22, and each of the rotor blades 22 includes a plurality of rotor blades 221; the stator element 3 includes The number of the fixed wings 31 is seven, and each of the fixed wings 31 includes a plurality of stator blades 311. Wherein, the upper and lower adjacent rotating wings 22 and Among the fixed blades 31, the inclination directions of the rotor blades 221 and the stator blades 311 are opposite; and the inclination angles of the upper rotor blades 221 / stator blades 311 are different from those of the lower rotor blades 221 / stator blades 311. Thereby, it is possible to ensure that the gas molecules G irreversibly flow from the intake port 12 to the exhaust port 13.

Further, the number of rotor blades 221 included in the first layer of rotating blades 22 preferably ranges from 16 to 22, and the preferred range of angle between each of the rotor blades 221 and a corresponding horizontal plane is 38 degrees to 45 degree. The preferred range of the number of rotor blades 221 included in the second layer of rotating blades 22 is from 28 to 35, with a preferred range of angles between each of the rotor blades 221 and a respective horizontal plane being between 32 and 38 degrees. The preferred range of the number of rotor blades 221 included in the third layer of rotating blades 22 is from 40 to 48, with a preferred range of angles between each of the rotor blades 221 and a respective horizontal plane being between 28 and 33 degrees. The preferred range of the number of rotor blades 221 included in the fourth layer of rotor blades 22 is from 40 to 48, with a preferred range of angles between each of the rotor blades 221 and a respective horizontal plane being between 28 and 33 degrees. The preferred range of the number of rotor blades 221 included in the fifth layer of rotary blades 22 is from 38 to 46, with a preferred range of angles between each of the rotor blades 221 and a respective horizontal plane being from 18 to 26 degrees. The preferred range of the number of rotor blades 221 included in the sixth layer of rotary blades 22 is from 32 to 37, with a preferred range of angles between each of the rotor blades 221 and a respective horizontal plane being between 13 and 18 degrees. The preferred range of the number of rotor blades 221 included in the seventh layer of rotary blades 22 is from 32 to 37, with a preferred range of angles between each of the rotor blades 221 and a respective horizontal plane being between 13 and 18 degrees. The preferred range of the number of rotor blades 221 included in the eighth layer of rotor blades 22 is from 32 to 37, with a preferred range of angles between each of the rotor blades 221 and a respective horizontal plane being between 13 and 18 degrees.

In addition, the number of stator blades 311 included in the first layer of fixed wings 31 preferably ranges from 25 to 32, and the preferred range of angle between each of the stator blades 311 and a corresponding horizontal plane is 38 to 45 degrees. . The second layer of fixed wings 31 is included The preferred range of the number of stator vanes 311 is from 38 to 46, with a preferred range of angle between each of the stator vanes 311 and a corresponding horizontal plane being from 32 to 38 degrees. The preferred range of the number of stator blades 311 included in the third layer of fixed wings 31 is 46 to 56, and the preferred range of angle between each of the stator blades 311 and a corresponding horizontal plane is 28 to 33 degrees. The number of stator blades 311 included in the fourth layer of fixed wings 31 preferably ranges from 45 to 53 pieces, and the angle between each of the stator blades 311 and a corresponding horizontal plane preferably ranges from 27 degrees to 32 degrees. The number of stator blades 311 included in the fifth layer fixed wing 31 is preferably in the range of 38 to 46, and the angle between each of the stator blades 311 and a corresponding horizontal plane is preferably in the range of 15 to 21 degrees. The number of stator blades 311 included in the sixth layer fixed wing 31 is preferably in the range of 38 to 46, and the angle between each of the stator blades 311 and a corresponding horizontal plane is preferably in the range of 13 to 18 degrees. The number of stator blades 311 included in the seventh layer fixed wing 31 is preferably in the range of 38 to 46, and the angle between each of the stator blades 311 and a corresponding horizontal plane is preferably in the range of 13 to 18 degrees.

Referring to FIG. 3 and FIG. 4, the inventors have found that the rotor element 2 rotating at a high speed in a high temperature environment easily forms a fragile point of fatigue cracking on the second seat 212 of the rotor seat 21; therefore, the second seat The reinforcing body 4 is provided at a specific position of the body 212, which is capable of resisting high temperature for a long period of time without affecting all the high-speed dynamic characteristics and vacuuming efficiency of the rotor element 2. Further, the second body 212 has a front end portion 2121 and a rear end portion 2122 extending from the end of the front end portion 2121. The rear end portion 2122 is closer to the exhaust port 13 than the front end portion 2121, and the rear end portion 2122 The thickness is smaller than the thickness of the front end portion 2121, and the reinforcing structure 4 is disposed around the rear end portion 2122.

In the present embodiment, the front end portion 2121 has a thickness h, and the rear end portion 2122 has a thickness greater than 2/3h but less than h; wherein the rear end portion 2122 is formed by mechanically removing a portion of the outer diameter material, but not Limited by this. The reinforcing structure 4 is a ring structure, and can be placed on the rear end portion 2122 in an ultra-low temperature environment close to minus 200 ° C, but not Preferably, the front end portion 2121 has an opposite inner peripheral wall W22 and an outer peripheral wall W23, wherein the inner peripheral wall W22 is closer to the high speed main shaft 23 than the outer peripheral wall W23, and the outer surface and the outer peripheral wall W23 of the reinforcing structure 4 Flush.

The material of the reinforcing structure 4 is titanium alloy or carbon fiber, but is not limited thereto. It is worth noting that although titanium alloy is 1.6 times heavier than aluminum alloy, the tensile strength of titanium alloy is close to that of special steel, which is twice that of aluminum alloy, and titanium alloy has excellent corrosion resistance and heat resistance; carbon fiber (again It is a kind of high-strength, high-modulus high-end fiber with light weight, high hardness, high chemical resistance, high temperature resistance and low thermal expansion. In other embodiments, the reinforcing structure 4 may be made of stainless steel, low alloy steel or heat resisting alloy, or other fiber materials such as glass fiber. ), Kevlar fiber, boron fiber, silicon carbide fiber, and the like.

The power base 5 has a bearing mechanism 51 disposed between the rotor base 21 and the high speed main shaft 23 to drive the rotor base 21 and the rotary wing 22 to rotate at a high speed through the high speed main shaft 23, thereby causing gas molecules to flow from the air inlet 12 to the row. Air port 13. In the present embodiment, the bearing mechanism 51 is an electromagnetic bearing including a motor distributed in the axial direction, an electromagnet group (not labeled), and the like; the bearing mechanism 51 can generate a magnetic force to support the rotor element 2, and the rotor element 2 floats in the axial direction and maintains a stable position in a stable suspension. Regarding the configuration of the bearing mechanism 51, it is well known to those skilled in the art, and thus will not be described in detail herein.

Referring to FIGS. 1 to 3, the turbo molecular pump P may further include a heating device 6 disposed around the power base 5 as needed. For example, when the turbomolecular pump P can be applied to an etching device to slow the formation of deposits, thereby extending the time interval of preventative maintenance (PM).

[Second embodiment]

Please refer to FIG. 8 , and please refer to FIG. 3 , the turbo molecular pump of this embodiment. The structural composition of P is substantially the same as that described in the first embodiment, and the main difference is that the reinforcing structure 4 is a composite structure.

In this embodiment, the reinforcing structure 4 includes a first strengthening layer 41 and a second strengthening layer 42 formed on the first reinforcing layer 41. The first reinforcing layer 41 is made of a titanium alloy, and the second reinforcing layer 42 is 42. The material is carbon fiber, but is not limited to this. In other embodiments, the material of the first strengthening layer 41 may be stainless steel, low alloy steel or heat resistant alloy, and the material of the second strengthening layer 42 may be glass fiber, Kevlar fiber, boron fiber or tantalum carbide fiber. The reinforcing structure 4 may also be formed by alternately stacking a plurality of first strengthening layers 41 and a plurality of second reinforcing layers 42.

[Third embodiment]

Referring to FIG. 9, the structural composition of the turbo molecular pump P of the present embodiment is substantially the same as that described in the first embodiment. The main difference is that the rear end portion 2122 of the second base 212 of the rotor seat 21 is not completely enhanced. Structure 4 is coated. In the present embodiment, the reinforcing structure 4 is spirally wound in the axial direction on the outer peripheral wall of the rear end portion 2122, but is not limited thereto. The reinforcing structure 4 may be a discontinuous structure, that is, formed on the outer peripheral wall of the rear end portion 2122 in a dispersed manner.

[Advantageous Effects of Embodiments]

One of the beneficial effects of the present invention is that the turbo molecular pump provided by the present invention can be provided with a "reinforcing structure disposed on the rotor seat and avoiding the coverage areas of the plurality of rotating blades and the plurality of fixed wings". Under the premise of not affecting all the high-speed dynamic characteristics and vacuuming efficiency of the rotor element, the fragile point of the fatigue deformation of the rotor component in the high temperature environment is avoided, thereby effectively extending the service life of the pump.

Furthermore, the turbo molecular pump provided by the invention can reduce the generation of deposits by heating, and can resist the high temperature working environment.

The above disclosure is only a preferred embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Equivalent technical changes made to the content are included in the scope of the patent application of the present invention.

Claims (11)

A turbo molecular pump comprising: a casing having a cavity; a stator element disposed in the cavity, wherein the stator component comprises a plurality of fixed wings; a rotor component, The rotor element is disposed in the cavity and has rotational freedom with respect to the stator element, wherein the rotor element includes a rotor seat and a plurality of rotating wings connected to the rotor seat, and a plurality of The rotating wing is alternately arranged with the plurality of fixed wings; and a reinforcing structure disposed on the rotor base and avoiding a plurality of the rotating wings and a plurality of covered areas of the fixed wings. The turbomolecular pump of claim 1, wherein the two ends of the outer casing respectively have an air inlet and an air outlet connected to the cavity, and the rotor base includes a first seat and a second seat body extending from an end of the first seat body, the first seat body being adjacent to the air inlet, the second seat body being adjacent to the air exhaust port, and the The outer diameter of the body is smaller than the outer diameter of the second seat body, wherein a plurality of the rotating wings are coupled to the first seat body. The turbomolecular pump of claim 2, wherein the reinforcing structure is disposed on the second seat. The turbo molecular pump according to claim 3, wherein the second seat body has a front end portion and a rear end portion extending from an end of the front end portion, the rear end portion being more than the front end portion Further closer to the exhaust port, and the thickness of the rear end portion is smaller than the thickness of the front end portion, wherein the reinforcing structure is disposed around the rear end portion. The turbomolecular pump of claim 4, wherein the front end portion has a thickness of h, and the rear end portion has a thickness greater than 2/3h but less than h. The turbo molecular pump of claim 4, wherein the rotor element further comprises a high speed main shaft, wherein the high speed main shaft is disposed in the rotor seat, wherein the front end portion has an inner peripheral wall and an outer peripheral wall with respect to the inner peripheral wall, and the inner peripheral wall is more than the outer peripheral wall Adjacent to the high speed spindle, wherein the reinforcing structure has an outer surface and the outer surface is flush with the outer peripheral wall. The turbomolecular pump of claim 4, wherein the reinforcing structure is a ring structure, and the reinforcing structure is made of titanium alloy or carbon fiber. The turbo molecular pump of claim 6, further comprising a power base for assembling the outer casing, the stator element and the rotor element, wherein the power base has a bearing mechanism The bearing mechanism is disposed between the rotor seat and the high speed main shaft for driving the rotor element through the high speed main shaft. The turbomolecular pump of claim 6, further comprising a heating device, and the heating device is disposed around the power base. The turbo molecular pump of claim 1, wherein the cavity is a vacuum chamber. A turbomolecular pump as claimed in claim 1 wherein each of said fixed wings comprises a plurality of stator blades, each of said rotor blades comprising a plurality of rotor blades.