CN117108477A

CN117108477A - Cryopump and preparation method thereof

Info

Publication number: CN117108477A
Application number: CN202311389952.2A
Authority: CN
Inventors: 汤洪明; 熊鹰; 刘德志
Original assignee: Suzhou Bapima Superconducting Technology Co ltd
Current assignee: Suzhou Bapima Superconducting Technology Co ltd
Priority date: 2023-10-25
Filing date: 2023-10-25
Publication date: 2023-11-24
Anticipated expiration: 2043-10-25
Also published as: CN117108477B

Abstract

The application belongs to the field of pump bodies, and relates to a low-temperature pump which comprises a refrigerator, a low-temperature pump body and a low-temperature plate, wherein the low-temperature plate comprises a first-stage cold screen, a first-stage baffle and a cold umbrella, the inside of the first-stage cold screen is hollow, one side of the first-stage cold screen is covered with the first-stage baffle, and the cold umbrella is arranged in the first-stage cold screen; a gap for passing gas is reserved between the cold umbrella and the first-stage cold screen and between the cold umbrella and the first-stage baffle; the secondary cold head of the refrigerator is connected with a cold umbrella; the cold umbrella comprises a cold umbrella top plate and a plurality of cold umbrella sheets, the center of the lower surface of the cold umbrella top plate is connected with the secondary cold head, the plurality of cold umbrella sheets are fixed on the lower surface of the cold umbrella top plate around the secondary cold head, and gaps for passing gas are reserved between the adjacent cold umbrella sheets. Under the structure, the II-type gas or the III-type gas can be in large-area direct contact with the cold umbrella sheets when entering between the cold umbrella sheets, and the I-type gas pumping speed is also improved when the first-stage baffle is large enough, so that the scheme of the application can obviously improve the pumping speed of at least one of the I-type gas, the II-type gas and the III-type gas.

Description

Cryopump and preparation method thereof

Technical Field

The application relates to the technical field of cryopumps, in particular to a cryopump and a preparation method thereof.

Background

The cryopump is a vacuum pump that adsorbs or condenses a gas on a cryopanel using ultra-low temperatures. In the prior art, as shown in fig. 1, the cryopump is composed of a refrigerator 1, a cryopump body and a cryopanel 3, the cryopanel 3 is connected to a refrigerating end of the refrigerator 1, the cryopanel 3 is connected to a normal temperature end of the refrigerator 1, and the cryopanel 3 and the cryopanel body are not in contact with each other. The refrigerator 1 is a two-stage refrigerator, the temperature of a first-stage cold head 11 of the refrigerator 1 is generally 40-100K, and the temperature of a second-stage cold head 12 is 10-20K. The low-temperature plate is divided into a first-stage cold screen 31 (80K cold screen), a first-stage baffle 32 (80K baffle) and a cold umbrella 33 (15K cold umbrella), wherein the first-stage cold screen 31 and the first-stage baffle 32 are connected with a first-stage cold head 11 of the refrigerator, and the temperature is equal to the temperature of the first-stage cold head 11. The 15K cold umbrella is connected with the secondary cold head 12 of the refrigerator, and the temperature is equal to that of the secondary cold head 12. In addition to condensing the type I gas, the primary cold screen 31 and the primary baffle 32 also have a function of pre-cooling the type II gas and the type III gas, wherein the type I gas, the type II gas, and the type III gas are divided by different liquefaction characteristics at low temperature; the 15K cold umbrella is used for condensing the II-type gas on the smooth surface and adsorbing the III-type gas by using the activated carbon adhered on the non-smooth surface. By the above condensation and adsorption of the gas, a high vacuum is provided.

The cryopump is widely used in semiconductor, panel and scientific research industries due to its high pumping speed and high cleanliness. As technology advances, there is a need to achieve a greater pumping rate for hydrogen or other gases in certain relatively small chambers.

In the conventional cryopump, as shown in fig. 1, the cold umbrella 33 has a tower-shaped structure, the activated carbon is adhered inside the cold umbrella, when hydrogen (class III gas or the like) or other gases pass through the first-stage baffle 32 and the gap between the first-stage baffle 32 and the first-stage cold screen 31, and enter the region of the cold umbrella 33, the hydrogen (class III gas or the like) or other gases need to be reflected for many times by the bottom, the side and the light surface of the first-stage cold screen 31 to reach the inside of the cold umbrella in order to be cooled by the cold umbrella 33, although in the process, the temperature of the hydrogen (class III gas or the like) or the other gases obtains the precooling of the cold screen and the baffle, and the proportion of the gases which can really reach the inside of the cold umbrella 33 is relatively low, and most of gas molecules can be reflected back into the vacuum cavity, so that the pumping speed is relatively small.

Disclosure of Invention

In view of the above, the technical scheme of the application provides a cryopump and a preparation method thereof for solving the problem that the conventional cryopump pointed out in the background art cannot meet the requirement of large pumping speed.

In a first aspect, the technical proposal provides a cryopump, which comprises a refrigerator, a cryopump body and a cryopanel,

the low-temperature plate comprises a first-stage cold screen, a first-stage baffle and a cold umbrella, the inside of the first-stage cold screen is hollow, one side of an air inlet end is covered with the first-stage baffle, and the cold umbrella is arranged in the first-stage cold screen; a gap for passing the gas is reserved between the cold umbrella and the first-stage cold screen and between the cold umbrella and the first-stage baffle;

the cold umbrella comprises a cold umbrella top plate and a plurality of cold umbrella sheets, the first surface of the cold umbrella top plate faces the first-stage baffle, the center of the second surface of the cold umbrella top plate is connected with a second-stage cold head of the refrigerator, the plurality of cold umbrella sheets are fixed on the second surface around the second-stage cold head, and gaps for passing gas are formed between adjacent cold umbrella sheets; the second surface is a back surface of the first surface.

Optionally, in the cryopump of the present application, a cold umbrella mounting seat is provided on the secondary cold head, and the second surface center is fixed on the cold umbrella mounting seat by a screw.

Optionally, in the cryopump of the present application, the cold umbrella top plate is circular or annular, and each cold umbrella sheet is arranged along a radial direction of the cold umbrella top plate.

Optionally, in the cryopump of the present application, the cold umbrella sheet includes a rectangular plane and a connecting sheet perpendicular to the plane; the cold umbrella top plate surrounds the center and is equipped with be used for with the first connecting hole of connection piece butt joint, every cold umbrella piece the connection piece position is equipped with the second connecting hole, cold umbrella piece is through passing first connecting hole, rivet fixing of second connecting hole is in the second surface.

Optionally, in the cryopump of the present application, the first-stage baffle includes a plurality of layers of baffles arranged from outside to inside, the outer ring baffle is located at the outermost side, the secondary outer ring baffle is located at the inner side of the outer ring baffle, and the projected outer contour area of the secondary outer ring baffle in the vertical direction of the cold umbrella top plate is greater than the projected area of the cold umbrella top plate.

Optionally, in the cryopump of the present application, a plurality of activated carbons are adhered to both side surfaces of each of the cold umbrella sheets.

In a second aspect, the present technical solution provides a method for manufacturing a cryopump, which is used for manufacturing the cryopump of the second aspect, and the method includes:

a raw material metal plate is taken, a rectangular area is defined on the raw material metal plate, a dividing line is taken along the length direction of the rectangular area, the rectangular area is divided into a first area and a second area, and the area of the second area is more than five times that of the first area;

cutting the outline of the rectangular area outside by using laser cutting equipment on a raw material metal plate, and reserving the rest rectangular area part;

bending the rectangular area part by 90 degrees along the dividing line through a bending machine, so that the metal plate of the first area part is perpendicular to the metal plate of the second area part;

coating the front and back sides of the metal plate of the second area part with adhesive, and then fully filling active carbon on the front and back sides of the metal plate of the second area part;

and cutting the metal plate into a plurality of L-shaped cold umbrella sheets by using laser cutting equipment at equal intervals along the direction perpendicular to the dividing line.

Optionally, in the method for preparing the temperature pump of the present application, in the step of coating the front and back sides of the metal plate in the second area portion with the adhesive, a manipulator with lifting and rotating functions may be further used, the manipulator clamps the metal plate in the first area portion, after the front side of the metal plate in the second area portion is coated with the adhesive, the manipulator is turned over after being lifted, so that the back side of the metal plate in the second area portion faces upwards, and then the adhesive is coated.

Optionally, in the method for preparing the temperature pump, in the step of coating the front and back sides of the metal plate in the second area part by using the adhesive, a manipulator with lifting and rotating functions is adopted, the metal plate is horizontally placed, the manipulator is operated to clamp the metal plate in the first area part, the manipulator is rotated for 90 degrees after lifting, so that the metal plate is vertically coated by the adhesive.

Optionally, in the method for preparing the temperature pump, in the step of coating the front and back sides of the metal plate of the second area part with the adhesive, a containing groove filled with activated carbon particles is formed, after the adhesive coating of the metal plate of the second area part is completed, the metal plate of the first area part is clamped by a manipulator, the metal plate of the second area part is driven to extend into the containing groove, and the metal plate of the second area part is driven to move so as to be fully contacted with the activated carbon particles, so that the activated carbon particles are fully adhered by the adhesive.

According to the cryopump provided by the technical scheme of the first aspect, a structure that a plurality of cold umbrella sheets are fixed on the second surface around the second-stage cold head is adopted, and gaps for passing gas are formed between adjacent cold umbrella sheets. Under the structure, class II gases such as nitrogen, argon and the like or class III gases such as hydrogen and the like can be in direct contact with the cold umbrella sheets in a large area when entering between the cold umbrella sheets, and part of the class III gases can be in contact with the two sides of the cold umbrella sheets after being reflected by the bottom and the side surfaces of the cold screen, only a small part of the gases are reflected back into the vacuum cavity, and the pumping speed of class I gases can be improved under the condition that the pumping speeds of class II gases and class III gases are not reduced when the area of the primary baffle is large enough.

According to the manufacturing method of the low-temperature pump provided by the technical scheme of the application, through the processes of laser cutting, bending and adhesive coating, the large-batch manufacturing of the L-shaped cold umbrella sheet can be completed in 5 steps, and the manufacturing method has the advantages of few procedures, low cost, easiness in operation and high feasibility.

Additional aspects and advantages of the application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the application.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:

FIG. 1 is a schematic diagram of the overall structure of a cryopump in the conventional art;

fig. 2 is a schematic diagram of the overall structure of the cryopump according to embodiment 1 of the present application;

FIG. 3 is a schematic diagram of a side view of a cold umbrella structure according to embodiment 1 of the present application;

fig. 4 is a schematic view of a bottom view of a cold umbrella structure according to embodiment 1 of the present application;

FIG. 5 is a schematic view of a cold umbrella provided in embodiment 2 of the present application;

FIG. 6 is a schematic diagram of a manufacturing process of a cold umbrella sheet of the cryopump according to embodiment 2 of the present application;

fig. 7 is a schematic diagram of the relationship between the area of the first-stage baffle and the area of the top plate of the cold umbrella of the cryopump provided in embodiment 3 of the present application.

The reference numerals in the figures are:

1. a refrigerating machine;

3. a low temperature plate;

4. activated carbon;

11. a primary cold head;

12. a second-stage cold head;

13. a cold umbrella mounting base;

31. a first-stage cold screen;

32. a first-stage baffle;

321. an outer ring baffle;

322. a secondary outer ring baffle;

33. a cold umbrella;

331. a cold umbrella top plate;

332. a cold umbrella sheet;

3321. a plane;

3322. and a connecting sheet.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the application are shown in the drawings, it should be understood that the application may be embodied in various forms and should not be limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the application may be practiced without one or more of these details. In other instances, well-known features have not been described in detail so as not to obscure the application; that is, not all features of an actual implementation are described in detail herein, and well-known functions and constructions are not described in detail.

In the drawings, the size of layers, regions, elements and their relative sizes may be exaggerated for clarity. Like numbers refer to like elements throughout.

It will be understood that when an element or layer is referred to as being "on" … …, "" adjacent to "… …," "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected to or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on" … …, "" directly adjacent to "… …," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application. When a second element, component, region, layer or section is discussed, it does not necessarily mean that the first element, component, region, layer or section is present.

Spatially relative terms, such as "under … …," "under … …," "below," "under … …," "above … …," "above," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "under" or "beneath" other elements would then be oriented "on" the other elements or features. Thus, the exemplary terms "under … …" and "under … …" may include both an upper and a lower orientation. The device may be otherwise oriented and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to provide a thorough understanding of the present application, detailed steps and detailed structures will be presented in the following description in order to explain the technical solution of the present application. Preferred embodiments of the present application are described in detail below, however, the present application may have other embodiments in addition to these detailed descriptions.

Example 1

This embodiment provides a cryopump, as shown in fig. 2-4, comprising a refrigerator 1, a cryopump body and a cryopanel 3,

the low-temperature plate 3 comprises a first-stage cold screen 31, a first-stage baffle 32 and a cold umbrella 33, wherein the first-stage cold screen 31 is hollow, one side of an air inlet end is covered with the first-stage baffle 32, and the cold umbrella 33 is arranged in the first-stage cold screen 31; a gap for passing the gas is reserved between the cold umbrella 33 and the first-stage cold screen 31 and between the cold umbrella 33 and the first-stage baffle 32;

the cold umbrella 33 includes a cold umbrella top plate 331 and a plurality of cold umbrella sheets 332, a first surface of the cold umbrella top plate 331 faces the first-stage baffle 32, a second surface center of the cold umbrella top plate 331 is connected with the second-stage cold head 12 of the refrigerator 1, a plurality of cold umbrella sheets 332 are fixed on the second surface around the second-stage cold head 12, and a gap for passing air is formed between adjacent cold umbrella sheets 332; the second surface is a back surface of the first surface.

In this embodiment, the refrigerator 1 includes a primary cold head 11 and a secondary cold head 12, where the primary cold head 11 is connected to the primary cold screen 31, and the secondary cold head 12 is connected to the cold umbrella 33.

Under the structure, the II-type gas such as nitrogen, argon and the like enters the region of the cold umbrella 33 through the first-stage baffle 32 and the gap between the first-stage baffle 32 and the first-stage cold screen 31, and is mainly condensed by the light surface of the upper surface of the cold umbrella top plate 331; when the cold umbrella sheet 332 of the embodiment does not adhere to activated carbon, the cold umbrella sheet 332 is a smooth surface structure, the pumping speed of the smooth surface structure for hydrogen is reduced, but the pumping speed for class II gases such as nitrogen is increased; the more the light surface, the more the pumping speed of the nitrogen is increased until a certain threshold is reached. Therefore, the cryopump of this embodiment may be used to increase the pumping rate of class II gases such as nitrogen.

Alternatively, in the cryopump of this embodiment, a plurality of activated carbons 4 are adhered to both side surfaces of each of the cold umbrella blades 332. Under the structure, the II-type gas such as nitrogen, argon and the like enters the region of the cold umbrella 33 through the first-stage baffle 32 and the gap between the first-stage baffle 32 and the first-stage cold screen 31, and is mainly condensed by the light surface of the upper surface of the cold umbrella top plate 331; hydrogen enters the region of the cold umbrella 33 through the gap between the first-stage baffle 32 and the first-stage cold screen 31, one part of the hydrogen can be directly contacted with the activated carbon 4 at the two sides of the cold umbrella 332 to be adsorbed, the other part of the hydrogen can be reflected by the bottom and the side surfaces of the first-stage cold screen 31 to be contacted with the activated carbon 4 at the two sides of the cold umbrella 332 to be adsorbed, and only a small part of the hydrogen can be reflected back into the vacuum cavity. Therefore, compared with the cold umbrella with the traditional structure, the cold umbrella structure of the embodiment has the advantage that the probability that hydrogen is contacted and adsorbed by the activated carbon is greatly improved.

In the cryogenic pump with a bore of 500mm, the conventional cold umbrella structure generally increases the pumping speed of hydrogen by increasing the amount of viscous carbon under the condition of the same first-stage baffle 32 and first-stage cold screen 31, but the pumping speed is limited in this way, and the pumping speed of hydrogen can only reach 15000L/s at maximum, while the pumping speed of the cold umbrella of the embodiment reaches 23000L/s, and the pumping speed increasing rate is 56%.

In addition, under the cold umbrella structure of the embodiment, since a part of hydrogen is directly irradiated onto the cold umbrella 33 without precooling, the temperature of the secondary cold head is improved compared with that of the conventional cold umbrella structure, the improvement range is related to the refrigeration power of the secondary cold head of the refrigerator, and the larger the refrigeration power of the secondary cold head is, the smaller the temperature improvement range is.

Optionally, as shown in fig. 2, in the cryopump of this embodiment, a cold umbrella mounting seat 13 is provided on the secondary cold head 12, and a second surface center of the cold umbrella top plate 331 is fixed on the cold umbrella mounting seat 13 by mounting a screw. The structure is convenient to install, and the specific installation mode is that the low-temperature pump shell is firstly installed on the installation flange of the refrigerator, the primary cold head 11 and the secondary cold head 12 of the refrigerator extend into the low-temperature pump shell, the primary cold screen 31 is installed on the primary cold head 11, the cold umbrella 33 is fixed on the secondary cold head 12 through the cold umbrella installation seat 13 by using screws, and then the primary baffle 32 is installed. In the installation process, the parts are not mutually blocked, and the operability is high.

Example 2

The present embodiment provides a cryopump, based on the solution of embodiment 1, as shown in fig. 5, the cold umbrella 332 of this embodiment includes a rectangular plane 3321 and a connecting piece 3322 perpendicular to the plane 3321; the cold umbrella top plate 331 is provided with a first connecting hole around the center for docking with the connecting piece 3322, a second connecting hole is provided at the position of the connecting piece 3322 of each cold umbrella piece 332, and the cold umbrella pieces 332 are fixed on the second surface of the cold umbrella top plate 331 by rivets penetrating through the first connecting hole and the second connecting hole. Under this structure, the shape of the cold umbrella sheet 332 is more regular, and the cold umbrella sheet is directly connected by rivets without using a welding process, so that the deformation of materials is small, and the assembled cold umbrella 33 is smoother and smoother as a whole, thereby being beneficial to gas contact.

Optionally, in the cryopump of this embodiment, the cold top plate 331 is circular or annular, as shown in fig. 4, each cold umbrella sheet 332 is arranged along a radial direction of the cold top plate 331, so as to form a form of concentrating from outside to inside, that is, a gap between the cold umbrella sheets 332 is wider at an outer side and narrower at an inner side, which is beneficial for rapid and massive gas entering into the inner side from the outer side and quickening large-area contact of the gas.

The embodiment provides a method for manufacturing a cryopump, which is used for manufacturing the cryopump, and when manufacturing the cold umbrella 332, as shown in fig. 6, the method includes:

s101, a raw material metal plate is taken, a rectangular area is defined on the raw material metal plate, a dividing line is taken along the length direction of the rectangular area, the rectangular area is divided into a first area and a second area, and the area of the second area is more than five times that of the first area;

s102, cutting the outline of the rectangular area outside by using laser cutting equipment on a raw material metal plate, and reserving the rest rectangular area part;

s103, bending the rectangular area part by 90 degrees along the dividing line through a bending machine, so that the metal plate of the first area part is perpendicular to the metal plate of the second area part;

s104, coating the front and back sides of the metal plate of the second area part by using adhesive, and then fully filling active carbon on the front and back sides of the metal plate of the second area part;

s105, the metal plate is cut into a plurality of L-shaped cold umbrella pieces 332 at equal intervals along the direction perpendicular to the dividing line by using a laser cutting device.

The manufacturing method of the cryopump provided by the embodiment can finish mass manufacturing of the L-shaped cold umbrella sheet by only 5 steps through the processes of laser cutting, bending and adhesive coating, has fewer procedures, low cost and high feasibility, and is easy to operate.

Optionally, in step S104, a manipulator with a lifting function is used to hold the metal plate of the first area, and after the front surface of the metal plate of the second area is coated with the adhesive, the manipulator is lifted to suspend the back surface of the metal plate of the second area, and then the adhesive is coated. This solution facilitates the reverse coating of the glue.

Optionally, in step S104, a manipulator with lifting and rotating functions may be further used, where the manipulator clamps the metal plate of the first area, after the front surface of the metal plate of the second area finishes the adhesive coating, the manipulator is turned over after being lifted, so that the back surface of the metal plate of the second area faces upwards, and then the adhesive coating is performed. The scheme can further facilitate the reverse side coating of the adhesive.

Optionally, when the length of the plane 3321 of the cold umbrella 332 to be manufactured is far greater than that of the connecting piece 3322, in step S104, a manipulator with lifting and rotating functions is used, the metal plate is placed horizontally, the manipulator is operated to clamp the metal plate of the first area, the manipulator is rotated by 90 degrees after lifting, the metal plate is made to be vertical, and then the glue is coated. This scheme is in order to avoid the plane 3321 length to be greater than connection piece 3322 when the second regional part weight of metal sheet is too big and is difficult to support, so the vertical metal sheet that sets up again after scribbles, and the bending resistance of vertical metal sheet is greater than horizontal metal sheet far away, so can not take place to crookedly.

Optionally, in step S104, a containing groove filled with activated carbon particles is provided, after the coating of the metal plate adhesive of the second area portion is completed, the metal plate of the first area portion is held by a manipulator, the metal plate of the second area portion is driven to extend into the containing groove, and the metal plate of the second area portion is driven to move so as to be fully contacted with the activated carbon particles, so that the activated carbon particles are fully adhered by the adhesive.

Example 3

The present embodiment provides a cryopump, and on the basis of the solution of embodiment 1, as shown in fig. 7, the structure of the primary baffle 32 is improved, where the improvement is as follows:

the first-stage baffle 32 includes a plurality of layers of baffles of arranging from outside to inside, and outer lane baffle 321 is located the outside, and secondary outer lane baffle 322 is located the inboard of outer lane baffle 321, secondary outer lane baffle 322 is in the projection outline area on the perpendicular direction of cold umbrella roof 331 (hereinafter referred to as the first direction) is greater than the projection area of cold umbrella roof 331. Projecting the outer contour as referred to herein means projecting the shape calculation area formed by the outer contour and the inner contour, and the projected actual area is the outer contour area minus the inner contour area.

The cryopump in this embodiment functions to boost the pumping rate of the class I gas. Example 1 provides a cryopump that can increase the pumping rate of a class II gas or a class III gas. The upper limit of the pumping speed increase is generally related to the structure and area of the primary baffle 32, and the smaller the projected area of the primary baffle 32 in the first direction, the greater the pumping speed. This also presents a new problem in that the projected area of the primary baffle 32 in the first direction is related to the class I gas extraction rate, and the smaller the projected area of the primary baffle 32 in the first direction, the smaller the water vapor extraction rate.

The cryogenic pump in the prior art has difficulty in improving the pumping speed of the I-type gas under the condition that the pumping speed of the hydrogen is unchanged. Because, once the class I gas pumping rate is to be increased, the projected area of the primary baffle 32 in the first direction must be increased, which results in a decrease in the hydrogen pumping rate, which is a counter effect. Therefore, in the prior art, the areas of the cold umbrella 33 and the primary baffle 32 of the high-pumping-speed cryopump are close to each other in the axial projection, and the projected area of the primary baffle 32 is slightly larger than that of the cold umbrella 33.

The cryopump in this embodiment can ensure that the projection area of the first-stage baffle 32 in the first direction is increased under the condition that the hydrogen pumping speed is still relatively large, thereby increasing the water vapor pumping speed. The more the projected area of the primary baffle 32 increases in the first direction, the greater the pumping speed for the class I gas increases. As shown in fig. 7, two rings of baffles are arranged on the periphery of the cold umbrella top plate 331, and if three rings of baffles are arranged on the periphery of the cold umbrella top plate 331, the pumping speed of the class I gas can be further improved. It should be noted that, because the increase of the area of the primary baffle 32 is limited in practice due to the diameter of the primary cold screen 31, the pumping speed of the class I gas is also improved in a limited range in the scheme of the present embodiment.

Specific data: taking the scheme in example 1 as an example, the hydrogen pumping speed reaches 23000L/s, and the pumping speed lifting rate is 56%. The cryopump according to example 1 of this example increased the area of the first stage baffle 32, with a hydrogen pumping rate increase from 15000L/s to 18500L/s by about 24%, and a water vapor pumping rate increase from 12000L/s to 16000L/s by about 33%.

It can be seen that the arrangement of the first-stage baffle 32 as shown in fig. 7 can make the cryopump of this embodiment increase the water vapor pumping rate without decreasing the hydrogen pumping rate. That is, the cryopump of this embodiment is capable of at least increasing the pumping speed of the class I gas, possibly increasing the pumping speed of the class II gas or the class III gas.

It should be understood that the above examples are illustrative and are not intended to encompass all possible implementations encompassed by the claims. Various modifications and changes may be made in the above embodiments without departing from the scope of the disclosure. Likewise, the individual features of the above embodiments can also be combined arbitrarily to form further embodiments of the application which may not be explicitly described. Therefore, the above examples merely represent several embodiments of the present application and do not limit the scope of protection of the patent of the present application.

Claims

1. The low-temperature pump comprises a refrigerator (1), a low-temperature pump body and a low-temperature plate (3), and is characterized in that,

the low-temperature plate (3) comprises a primary cold screen (31), a primary baffle (32) and a cold umbrella (33), wherein the primary cold screen (31) is hollow, one side of an air inlet end is covered with the primary baffle (32), and the cold umbrella (33) is arranged in the primary cold screen (31); gaps for passing gas are formed between the cold umbrella (33) and the primary cold screen (31) and between the cold umbrella and the primary baffle (32);

the cold umbrella (33) comprises a cold umbrella top plate (331) and a plurality of cold umbrella sheets (332), the first surface of the cold umbrella top plate (331) faces the first-stage baffle (32), the center of the second surface of the cold umbrella top plate (331) is connected with the second-stage cold head (12) of the refrigerator (1), the plurality of cold umbrella sheets (332) are fixed on the second surface around the second-stage cold head (12), and gaps for passing gas are reserved between the adjacent cold umbrella sheets (332); the second surface is a back surface of the first surface.

2. The cryopump of claim 1, wherein the cold umbrella blade (332) includes a rectangular shaped plane (3321) and a connecting piece (3322) perpendicular to the plane (3321); the cold umbrella top plate (331) surrounds the center and is equipped with and is used for with the first connecting hole of connection piece (3322) butt joint, every cold umbrella piece (332) connection piece (3322) position is equipped with the second connecting hole, cold umbrella piece (332) are through passing first connecting hole, rivet fixing of second connecting hole are in the second surface.

3. Cryopump according to claim 1, characterized in that the secondary coldhead (12) is provided with a cold umbrella mount (13), the second surface centre being fixed to the cold umbrella mount (13) by means of a screw mounting.

4. Cryopump according to claim 2, wherein the cold umbrella top plate (331) is circular or annular, each cold umbrella tab (332) being arranged in a radial direction of the cold umbrella top plate (331).

5. The cryopump of any one of claims 1 to 4, wherein the primary baffle (32) includes a plurality of layers of baffles arranged from an outer side to an inner side, an outer ring baffle (321) is located at an outermost side, a secondary outer ring baffle (322) is located at an inner side of the outer ring baffle (321), and a projected outer contour area of the secondary outer ring baffle (322) in a vertical direction of the cold top plate (331) is larger than a projected area of the cold top plate (331).

6. Cryopump according to any of claims 1-4, wherein a number of activated carbons (4) are adhered to both side surfaces of each cold umbrella blade (332).

7. A method of manufacturing a cryopump, for manufacturing a cryopump according to any one of claims 1 to 6, the method comprising, in manufacturing the cold umbrella sheet (332):

the metal plate is cut into a plurality of L-shaped cold umbrella blades (332) at equal intervals along the direction perpendicular to the dividing line by using a laser cutting device.

8. The method of manufacturing a cryopump of claim 7, wherein in the step of coating the front and rear surfaces of the metal plate of the second area portion with the adhesive, a robot having a lifting and rotating function is further used to hold the metal plate of the first area portion, and when the front surface of the metal plate of the second area portion is coated with the adhesive, the robot is turned over after lifting so that the rear surface of the metal plate of the second area portion faces upward, and then the adhesive is coated.

9. The method of manufacturing a cryopump of claim 7, wherein in the step of coating the front and rear sides of the metal plate of the second region portion with the adhesive, a robot having a lifting and rotating function is used, the metal plate is placed horizontally, the robot is operated to hold the metal plate of the first region portion, the robot is rotated by 90 degrees after lifting, the metal plate is made to be vertical, and then the coating of the adhesive is performed.

10. The method of manufacturing a cryopump according to claim 8 or 9, wherein in the step of coating the front and rear surfaces of the metal plate of the second region portion with the adhesive, a receiving groove filled with activated carbon particles is provided, and after the adhesive coating of the metal plate of the second region portion is completed, the metal plate of the first region portion is held by a robot, the metal plate of the second region portion is driven to extend into the receiving groove, and the metal plate of the second region portion is driven to move so as to be in sufficient contact with the activated carbon particles, so that the activated carbon particles are sufficiently adhered by the adhesive.