Low-temperature vacuum pump with efficient adsorption and stable vacuum

Abstract

The utility model relates to the technical field of vacuum pumps, in particular to an efficient-adsorption and stable-vacuum low-temperature vacuum pump which comprises a pump shell, a vacuum assembly and a refrigeration assembly. The vacuum assembly and the refrigeration assembly are arranged in the pump shell, gas can be adsorbed or condensed at low temperature, the needed vacuum environment can be rapidly achieved, the stable vacuum state can be kept, and the machining precision is guaranteed. Through the radiation screen of the vacuum assembly, heat energy in the environment can be reflected, fluctuation possibly caused by heat radiation to the vacuum environment is reduced, and stability is good; the first baffle, the second baffle and the cold umbrella are arranged to be matched with the adsorbent, gas molecules in the environment are subjected to multi-stage adsorption or condensation at the low temperature, and efficient adsorption is achieved to achieve the needed vacuum environment; the multi-stage air cylinder of the refrigeration assembly is arranged, compressed helium in the air cylinder expands to do work for refrigeration, a low-temperature state is provided for structures such as a radiation screen and a cold umbrella, and rapid adsorption and solidification of gas molecules are completed.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum pumps, in particular to a low-temperature vacuum pump with high-efficiency adsorption and stable vacuum. Background Art

[0002] Low-temperature vacuum pumps are widely used in the research and production of semiconductors and integrated circuits, as well as in molecular beam research, vacuum coating equipment, vacuum surface analysis instruments, ion implanters, space simulation devices and other industries due to their advantages such as high vacuum degree and high cleanliness, especially in vacuum coating and other processing processes that require a stable vacuum environment. At present, during the use of cryopumps, they are affected by external environmental factors, and the temperature or vacuum degree of the processing environment is prone to fluctuations, and the stability is poor, which affects the precision of semiconductor processing. Therefore, based on the above problems, the existing technology needs to be further improved. Utility Model Content

[0003] The utility model aims to provide a low-temperature vacuum pump with controllable pumping rate and pumping capacity, so as to solve the prior art problems existing in the above-mentioned background technology.

[0004] In order to solve the above-mentioned technical problems, the technical solution provided by the utility model is as follows: a low-temperature vacuum pump with efficient adsorption and stable vacuum is provided, comprising a pump housing, a vacuum component and a refrigeration component, the vacuum component comprising a radiation screen, a first baffle, a second baffle and a cold umbrella and all of which are arranged in the pump housing, the first baffle, the second baffle and the cold umbrella are all provided with adsorbents for adsorption or condensation of gas molecules; the refrigeration component comprises a primary cylinder and a secondary cylinder, the head end of the primary cylinder is provided with a driving component, the end of which is connected to the head end of the secondary cylinder, the end of the secondary cylinder is arranged in the cold umbrella, and refrigeration gas flows in the refrigeration component to provide a low-temperature environment for the vacuum component.

[0005] Based on the above technical solution, the radiation screen is fixedly arranged on the inner wall of the pump housing and has a matching shape, the first baffle is fixedly arranged at the top of the inner wall of the radiation screen, the second baffle is fixedly arranged on the inner side of the first baffle, and the cold umbrella is arranged inside the radiation screen and below the first baffle and the second baffle.

[0006] Based on the above technical solution, the first baffle plate includes a baffle plate end plate and a baffle plate blade. The baffle plate end plate is configured as a circular end plate. A plurality of groups of long holes are arranged on the baffle plate end plate. One end of the baffle plate blade is arranged at the bottom end of the long hole.

[0007] Based on the above technical solution, the baffle blades are arranged obliquely to the baffle end plates.

[0008] On the basis of the above technical solution, each group of long strip holes is provided with a plurality of holes along the diameter direction of the baffle end plate, and the long strip holes are arranged in an arc shape and the lengths increase successively.

[0009] Based on the above technical solution, the second baffle includes a fixed plate and an annular baffle, the fixed plate is arranged at the center position of the axis of the radiation screen, the annular baffle is arranged on the outside of the fixed plate, and there are multiple annular baffles and the diameter increases from the inside to the outside.

[0010] Based on the above technical solution, the cold umbrella includes a plurality of cold umbrella pieces and are evenly arranged from top to bottom. The cold umbrella pieces include end plates and side plates. The side plates are fixedly arranged on the side walls of the end plates and are inclined with respect to the end plates.

[0011] Based on the above technical solution, a primary piston is arranged in the primary cylinder, a secondary piston is arranged in the secondary cylinder, the driving assembly is arranged at the head end of the primary piston, a multi-layer copper mesh is arranged in the primary piston, and lead particles are filled in the secondary piston.

[0012] Based on the above technical solution, the driving assembly includes a driving motor, an eccentric shaft, an eccentric wheel and a driving frame. The eccentric shaft is driven to rotate by the driving motor. The eccentric wheel is fixedly mounted on the eccentric shaft. The eccentric wheel is arranged in the driving frame. The driving frame is connected to the head end of the first-stage piston.

[0013] On the basis of the above technical solution, a regenerative heating device is further provided at the head end of the secondary cylinder, and the regenerative heating device is configured as a resistance heating rod.

[0014] The beneficial effects of the technical solution provided by the utility model are:

[0015] The utility model provides a low-temperature vacuum pump with high efficiency adsorption and stable vacuum. By arranging a vacuum component and a refrigeration component in the pump housing, gas adsorption or condensation can be achieved at low temperature, the required vacuum environment can be quickly achieved and a stable vacuum state can be maintained. It is particularly suitable for semiconductor processing, providing a pure vacuum environment, not introducing other impurities, and ensuring processing accuracy. Specifically, through the radiation screen of the vacuum component, the heat energy in the environment can be reflected, the heat radiation to the internal cold umbrella structure can be reduced, and the fluctuations that may be caused by heat radiation to the vacuum environment can be reduced, and the stability is good; by arranging the first baffle, the second baffle and the cold umbrella, in combination with the adsorbent thereon, the gas molecules in the environment can be adsorbed or condensed in multiple stages at low temperature, and high efficiency adsorption can be achieved to achieve the required vacuum environment; at the same time, the first baffle and the second baffle are arranged on the outside of the cold umbrella, and the heat radiation in the environment can also be reflected, and the influence of external environmental factors on the vacuum degree and its stability can be reduced, and the stability of the vacuum environment is good; by arranging the multi-stage cylinder in the refrigeration component and the refrigeration gas flowing therein, the compressed helium in the cylinder is expanded to do work for refrigeration, and a low temperature state is provided for structures such as the radiation screen and the cold umbrella, and the rapid adsorption and solidification of gas molecules is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 It is a schematic diagram of the internal structure of the vacuum component in the utility model;

[0018] Figure 3 It is a structural schematic diagram of the first baffle in the utility model;

[0019] Figure 4 It is a structural schematic diagram of the second baffle in the utility model;

[0020] Figure 5 It is a structural schematic diagram of the cooling umbrella in the utility model;

[0021] Figure 6 It is a structural schematic diagram of the refrigeration component in the utility model;

[0022] Figure 7 It is a schematic diagram of the internal structure of the refrigeration component in the utility model; DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0024] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In the description of the present invention, it should be understood that the terms "left", "right", "front", "back", "top", "bottom", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0026] like Figures 1 to 7 As shown, a low-temperature vacuum pump with efficient adsorption and stable vacuum includes a pump housing 1, a vacuum component 2 and a refrigeration component 3. The vacuum component 2 includes a radiation screen 21, a first baffle 22, a second baffle 23 and a cold umbrella 24, and all are arranged in the pump housing 1. The first baffle 22, the second baffle 23 and the cold umbrella 24 are all provided with adsorbents for adsorption or condensation of gas molecules; the refrigeration component 3 includes a primary cylinder 31 and a secondary cylinder 32. The head end of the primary cylinder 31 is provided with a driving component 35, and the end is connected to the head end of the secondary cylinder 32. The end of the secondary cylinder 32 is arranged in the cold umbrella 24. Refrigeration gas flows in the refrigeration component 3 to provide a low-temperature environment for the vacuum component.

[0027] The utility model provides a low-temperature vacuum pump with efficient adsorption and stable vacuum. By arranging a vacuum component 2 and a refrigeration component 3 in a pump housing 1, gas adsorption or condensation can be achieved at a low temperature, the required vacuum environment can be quickly achieved and a stable vacuum state can be maintained. The utility model is particularly suitable for semiconductor processing, providing a pure vacuum environment without introducing other impurities, and ensuring processing accuracy. Specifically, a flange is provided at the end of the pump housing for installation and disassembly with the process chamber; the radiation screen 21 of the vacuum component 2 can reflect the heat energy in the environment, reduce the heat radiation to the internal cold umbrella structure, reduce the fluctuation of the vacuum environment caused by heat radiation, and have good stability; by setting the first baffle, the second baffle and the cold umbrella, in conjunction with the adsorbent thereon, the gas molecules in the environment can be adsorbed or condensed in multiple stages at low temperature, and efficient adsorption can be achieved to achieve the required vacuum environment; at the same time, the first baffle and the second baffle are arranged on the outside of the cold umbrella, and can also reflect the heat radiation in the environment, reduce the influence of external environmental factors on the vacuum degree and its stability, and the stability of the vacuum environment is good; by setting the multi-stage cylinder in the refrigeration component 3 and the refrigeration gas flowing inside, refrigeration is performed by the expansion of the compressed helium inside the cylinder, providing a low temperature state for structures such as the radiation screen and the cold umbrella, and completing the rapid adsorption and solidification of the gas molecules. Preferably, the adsorbent is activated carbon, and the refrigeration gas is helium.

[0028] Based on the above technical solution, the radiation screen 21 is fixedly arranged on the inner wall of the pump housing 1 and has a matching shape, the first baffle 22 is fixedly arranged at the top of the inner wall of the radiation screen 21, the second baffle 23 is fixedly arranged on the inner side of the first baffle 22, and the cold umbrella 24 is arranged inside the radiation screen 21 and below the first baffle 22 and the second baffle 23.

[0029] By arranging the first baffle 22 and the second baffle 23 structure in the vacuum component 2, and cooperating with the adsorbent thereon, a first adsorption structure is formed in a low-temperature environment, providing adsorption and solidification positions for gas molecules, thereby achieving the high vacuum degree required in the processing environment, and at the same time, it can also effectively reduce the direct impact of the gas on the internal cold umbrella 24, play a protective role, and extend the service life of the cold umbrella 24; by arranging the cold umbrella 24 in the radiation screen 21, a second adsorption structure is formed in a low-temperature environment, providing adsorption and solidification sites for most gas molecules, and quickly achieving a high vacuum environment.

[0030] In a more preferred embodiment, a gap is provided between the outer wall of the radiation screen 21 and the inner wall of the pump housing 1, and a through hole is provided at the bottom of the radiation screen 21. In a preferred embodiment, a gap is provided between the pump housing 1 and the radiation screen 21 to form an auxiliary gas channel, so that the gas can enter the interior through the cold umbrella structure during the flow process, and the gas can directly enter the cold umbrella structure, and at the same time, part of the gas can enter the cold umbrella structure through the auxiliary gas channel and the through hole, so that the gas molecules can be quickly and effectively adsorbed and solidified.

[0031] Based on the above technical solution, the first baffle 22 includes a baffle end plate 221 and a baffle blade 222. The baffle end plate 221 is configured as a circular end plate. A plurality of groups of long holes 223 are provided on the baffle end plate 221. One end of the baffle blade 222 is provided at the bottom of the long hole 223.

[0032] Based on the above technical solution, the baffle blades 222 are arranged obliquely to the baffle end plate 221 .

[0033] A first baffle 22 is provided in the vacuum component 2, and adsorbents are provided on the baffle end plate 221 and the baffle blades 222 to adsorb and solidify the gas, so as to quickly achieve a vacuum environment. At the same time, the baffle blades 222 are provided with multiple groups of long holes 223 corresponding to the baffle blades 222 and are inclined, which can increase the effective adsorption area and radiate part of the heat to reduce the influence of thermal radiation on the vacuum environment, and the vacuum stability is good; the first baffle 22 is provided with multiple groups of long holes 223 and each group is provided with multiple long holes 223, which can provide a flow channel for the gas, so that the gas enters the cold umbrella structure for adsorption and solidification, and a vacuum state is achieved; in a preferred embodiment, the baffle blades 222 are obtained by directly stamping downward from the baffle end plate 221, that is, only one edge of the baffle blades 222 is left connected to the baffle end plate 221, and the other three edges are separated from the baffle end plate 221 after being stamped, forming an inclined state with the baffle end plate 221.

[0034] On the basis of the above technical solution, each group of long holes 223 is provided with a plurality of holes along the diameter direction of the baffle end plate 221, and the long holes 223 are provided in an arc shape and the lengths are increased successively. In a preferred embodiment, the long holes 223 are provided in an arc shape and the lengths of the plurality of long holes 223 in each group are increased successively, which can increase the effective adsorption area of ​​the gas, and at the same time can also increase the gas flow, so as to quickly and efficiently achieve the required vacuum environment, and can also maintain the stability of the vacuum state.

[0035] Based on the above technical solution, the second baffle 23 includes a fixing plate 231 and an annular baffle 232. The fixing plate 231 is arranged at the center position of the axis of the radiation screen 21, and the annular baffle 232 is arranged on the outside of the fixing plate 231. There are multiple annular baffles 232 and the diameter increases from the inside to the outside.

[0036] By providing a second baffle 23 in the vacuum component 2, that is, providing a plurality of circular baffles 232 with successively increasing diameters, the gas adsorption area is large, ensuring that the vacuum state is quickly achieved and the vacuum effect is good; more preferably, the circular baffles 232 are all inclined, which can increase the effective adsorption area of ​​the gas. At the same time, the inclined circular baffles 232 can also radiate part of the heat to maintain the stability of the vacuum environment.

[0037] Based on the above technical solution, the cold umbrella 24 includes a plurality of cold umbrella pieces and is evenly arranged from top to bottom. The cold umbrella pieces include an end plate 241 and a side plate 242 . The side plate 242 is fixedly arranged on the side wall of the end plate 241 and is inclined with respect to the end plate 241 .

[0038] By arranging a cold umbrella 24 in the vacuum assembly 2, including a plurality of cold umbrella sheets from top to bottom, and cooperating with the adsorbent thereon, more adsorption and solidification sites are provided for gas molecules, so that the desired vacuum state can be quickly achieved; more preferably, the angle between the side plate 242 and the end plate 241 in the cold umbrella sheet is an obtuse angle, so that the side plate 242 can reflect a part of the heat radiation, reduce the adverse effect of heat on the temperature and vacuum degree, and reduce the fluctuation of the vacuum degree. Specifically, as Figure 5 As shown, the cold umbrella pieces are all fixedly arranged on the mounting frame 25, and the mounting frame 25 is fixedly connected to the refrigeration assembly 3. Except for the cold umbrella piece located at the top, the sides of the other cold umbrella pieces are provided with notches, mainly for adapting to the installation of the cylinder part in the refrigeration assembly; the center positions of the other cold umbrella pieces are all provided with openings, and through grooves are formed in the radial direction. The mounting frame 25 is arranged in the through groove, which is convenient for fixing the cold umbrella pieces, and also promotes the rapid flow of gas and the adsorption and solidification of the molecules contained therein.

[0039] In a more preferred embodiment, a plurality of cold umbrella sheets are fixedly mounted on the mounting frame 25, a plurality of through holes 243 are provided on the end surface of a cold umbrella sheet at the top, and a plurality of through holes are also provided on the mounting frame 25. The mounting frame 25 can assist in the fixing and disassembly of the plurality of cold umbrella sheets, and cooperate with the through holes provided thereon to facilitate the flow of gas and drive the molecules existing in the environment to be more fully adsorbed, thereby meeting the vacuum environment with high vacuum requirements.

[0040] On the basis of the above technical solution, a primary piston 33 is arranged in the primary cylinder 31, a secondary piston 34 is arranged in the secondary cylinder 32, the driving assembly 35 is arranged at the head end of the primary piston 33, a multi-layer copper mesh 331 is arranged in the primary piston 33, and the secondary piston 34 is filled with lead particles.

[0041] By providing a primary cylinder 31 and a secondary cylinder 32 in the refrigeration component 3, a low temperature environment can be provided for structures such as the radiation screen 21 and the cold umbrella, so that gas adsorption can be facilitated under the action of the adsorbent to achieve a vacuum environment; specifically, the primary cylinder 32 is in thermal contact with the radiation screen 21, and the secondary cylinder 31 is in thermal contact with the cold umbrella 24. The primary piston 33 is driven by the driving component 35, and the reciprocating motion of the secondary piston 34 drives the refrigeration gas to expand and do work, thereby achieving refrigeration, providing the required adsorption temperature for the radiation screen 21 and the cold umbrella 24 structure, thereby achieving adsorption and solidification of gas molecules in the environment, and achieving a vacuum degree. At the same time, preferably, the secondary cylinder 32 is fixedly arranged in the cold umbrella structure through the mounting frame 25, and the mounting frame 25 is fixedly connected to the inside of the cold umbrella sheet, and the cold umbrella sheet is provided with a through groove adapted to the mounting frame 25.

[0042] In a preferred embodiment, a multi-layer copper mesh 331 is provided in the first piston 33, and lead particles are filled in the second piston 34. Both ends of the first piston 33 and the second piston 34 are provided with air inlet and air outlet holes for the refrigerant gas to enter and exit. The air inlet and air outlet holes are provided to realize the flow of the refrigerant gas in the first piston 33 and the second piston 34; especially when flowing through the first piston 33, in this preferred embodiment, a multi-layer dense copper mesh 331 is provided in the first piston 33, which has the function of cold storage and heat absorption, realizes the heat exchange of the helium passing through, reduces the drift and fluctuation of the temperature and vacuum degree, and ensures the stability of the processing environment; the lead particles filled in the second piston 34 also have the function of filtering, and in the process of the helium flowing, it can realize the removal of impurities in the helium, improve the work efficiency of the helium, and improve the cleanliness of the vacuum environment.

[0043] Based on the above technical solution, the driving assembly 35 includes a driving motor 351, an eccentric shaft 352, an eccentric wheel 353 and a driving frame 354. The eccentric shaft 352 is driven to rotate by the driving motor 351. The eccentric wheel 353 is fixedly mounted on the eccentric shaft 352. The eccentric wheel 353 is arranged in the driving frame 354. The driving frame 354 is connected to the front end of the first-stage piston 33.

[0044] Specifically, the driving frame 354 is arranged in a middle shape; the driving motor 351 drives the eccentric shaft 352 and the eccentric wheel 353 thereon to move, driving the driving frame 354 to reciprocate, thereby driving the reciprocating movement of the primary piston 33 and the secondary piston 34, doing work on helium, compressing helium to absorb heat during the compression and expansion processes, reducing the temperatures of the primary cylinder 31 and the secondary cylinder 32, achieving a low-temperature state in the radiation shield 21 and the cold umbrella 24 structures, and thus enabling the cold umbrella structure to adsorb molecules in the gas at a low-temperature state.

[0045] Based on the above technical solution, a regeneration heating device 6 is further provided at the head end of the secondary cylinder 32, and the regeneration heating device 6 is set as a resistance heating rod.

[0046] By providing the resistance heating rod 6, the refrigeration component 3 and the connected cold umbrella structure can be heated; when the low-temperature pump needs to be regenerated and maintained, when releasing the molecules adsorbed and solidified in the cold umbrella, the resistance heating rod is used to heat the cold umbrella structure to release the vacuum degree, facilitating daily maintenance such as removing impurities or replacing cold umbrella components, and making the use more convenient and fast.

[0047] During use, the low-temperature vacuum pump in the present invention is hung on the semiconductor processing process chamber (abbreviated as the process chamber). According to actual usage requirements, multiple low-temperature pump devices can be provided on the process chamber to ensure the vacuum degree in the process chamber; helium is pressurized by a compressor and transported into the low-temperature vacuum pump, and the helium inlet and outlet pipes are correspondingly arranged on the inlet valve and the outlet valve to realize the process of helium inlet and outlet; then, under the driving action of the driving component, the primary piston and the secondary piston perform reciprocating movements, helium expands and absorbs heat for refrigeration, achieving a low-temperature state of the primary cylinder, the secondary cylinder, the radiation shield, and the cold umbrella structure, and discharging the heat-exchanged helium; at a low temperature close to absolute zero, the adsorbent attached to the cold umbrella structure can adsorb and solidify gas molecules in the environment, forming a high-vacuum environment, and a vacuum pressure of 10 -9 Pa can be achieved, realizing a pure vacuum space, which is especially suitable for the semiconductor industry with high processing accuracy requirements, such as the processing of heavy metal coating of chips. When the low-temperature vacuum pump needs to be regenerated, the resistance heating rod can be used to heat and regenerate the refrigeration component and the vacuum component, releasing the molecules adsorbed and solidified on the cold umbrella structure, facilitating the cleaning of impurities and replacement of internal structures such as the cold umbrella, and making the operation more convenient.

[0048] The basic principle and main features of the utility model are shown and described above. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments. Therefore, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the appended claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the utility model.

[0049] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum, characterized in that: The invention comprises a pump housing (1), a vacuum component (2) and a refrigeration component (3); the vacuum component (2) comprises a radiation screen (21), a first baffle (22), a second baffle (23) and a cold umbrella (24), all of which are arranged in the pump housing (1); the first baffle (22), the second baffle (23) and the cold umbrella (24) are all provided with adsorbents for adsorbing or condensing gas molecules; the refrigeration component (3) comprises a primary cylinder (31) and a secondary cylinder (32); the first end of the primary cylinder (31) is provided with a driving component (35), and the end thereof is connected to the first end of the secondary cylinder (32); the end of the secondary cylinder (32) is arranged in the cold umbrella (24); refrigeration gas flows in the refrigeration component (3) for providing a low-temperature environment for the vacuum component.

2. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 1, characterized in that: The radiation screen (21) is fixedly arranged on the inner wall of the pump housing (1) and has a matching shape, the first baffle (22) is fixedly arranged at the top of the inner wall of the radiation screen (21), the second baffle (23) is fixedly arranged on the inner side of the first baffle (22), and the cold umbrella (24) is arranged inside the radiation screen (21) and below the first baffle (22) and the second baffle (23).

3. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 1, characterized in that: The first baffle plate (22) comprises a baffle plate end plate (221) and a baffle plate blade (222); the baffle plate end plate (221) is arranged as a circular ring end plate; a plurality of groups of long strip holes (223) are arranged on the baffle plate end plate (221); one end of the baffle plate blade (222) is arranged at the bottom end of the long strip hole (223).

4. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 3, characterized in that: The baffle blades (222) are arranged obliquely to the baffle end plate (221).

5. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 3, characterized in that: Each group of elongated holes (223) is provided with a plurality of holes along the diameter direction of the baffle end plate (221), and the elongated holes (223) are arranged in an arc shape and their lengths increase successively.

6. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 1, characterized in that: The second baffle (23) comprises a fixing plate (231) and an annular blocking plate (232), wherein the fixing plate (231) is arranged at the center position of the axis of the radiation screen (21), and the annular blocking plate (232) is arranged on the outside of the fixing plate (231), and a plurality of the annular blocking plates (232) are arranged, and the diameters of the annular blocking plates (232) increase sequentially from the inside to the outside.

7. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 1, characterized in that: The cold umbrella (24) includes a plurality of cold umbrella pieces which are evenly arranged from top to bottom, and the cold umbrella pieces include an end plate (241) and a side plate (242), wherein the side plate (242) is fixedly arranged on the side wall of the end plate (241) and is inclined with respect to the end plate (241).

8. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 1, characterized in that: A primary piston (33) is arranged in the primary cylinder (31), a secondary piston (34) is arranged in the secondary cylinder (32), the driving assembly (35) is arranged at the head end of the primary piston (33), a multi-layer copper mesh (331) is arranged in the primary piston (33), and lead particles are filled in the secondary piston (34).

9. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 1, characterized in that: The driving assembly (35) comprises a driving motor (351), an eccentric shaft (352), an eccentric wheel (353) and a driving frame (354); the eccentric shaft (352) is driven to rotate by the driving motor (351); the eccentric wheel (353) is fixedly sleeved on the eccentric shaft (352); the eccentric wheel (353) is arranged in the driving frame (354); and the driving frame (354) is connected to the front end of the primary piston (33).

10. A cryogenic vacuum pump with high adsorption efficiency and stable vacuum according to claim 1, characterized in that: The head end of the secondary cylinder (32) is also provided with a regenerative heating device (6), and the regenerative heating device (6) is configured as a resistance heating rod.

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