Thin low-temperature cold trap capable of adjusting water vapor pumping speed

Abstract

The utility model discloses a thin low-temperature cold trap capable of adjusting water vapor pumping speed, which comprises a shell, a condensing plate assembly and a refrigerating machine, two communicated cavity structures are arranged in the shell, the refrigerating machine is arranged in one cavity, the condensing plate assembly is arranged in the other cavity, and the refrigerating machine is arranged in the other cavity. A connecting plate on a first-stage cold head of the refrigerating machine can stretch into the other cavity and is connected with a condensation plate assembly, the condensation plate assembly comprises a plurality of condensation plates, and the condensation plates can be configured to form incidence holes with variable sizes. According to the utility model, the incidence holes with variable sizes can be formed in the condensing plate assembly, namely, condensing areas with different sizes can be adjusted, and the condensing plate area which is large enough can ensure that water vapor is directly condensed into ice after touching the condensing plate, so that the water vapor pumping speed can be improved, and the water vapor removing efficiency is also improved.

Description

Technical Field

[0001] The utility model relates to the technical field of low-temperature cold trap equipment, and more specifically to a thin low-temperature cold trap capable of adjusting water vapor extraction speed. Background Art

[0002] The cryogenic cold trap is also called a water pump because it is mainly used to extract water vapor. When the vacuum chamber is evacuated, the water adsorbed on the inner wall surface will slowly desorb, so at a pressure below 10-3Torr, the water vapor content in the residual gas load exceeds 97%. Therefore, water becomes the main obstacle for the vacuum chamber to reach the background pressure, and in many semiconductor processes, water will hinder chemical properties and affect output. In order to maximize process capacity output, it is very important to increase the pumping speed of water vapor. Utility Model Content

[0003] The technical problem to be solved by the utility model is how to provide a low-temperature cold trap capable of adapting to the regulation of water vapor extraction speed.

[0004] The utility model solves the above-mentioned technical problems through the following technical means: a thin low-temperature cold trap with adjustable water vapor extraction speed, including a shell, a condensation plate assembly, and a refrigerator, wherein the shell is provided with two mutually interpenetrating cavity structures, one of the cavities is provided with a refrigerator, and the other cavity is provided with a condensation plate assembly, the connecting plate on the first-level cold head of the refrigerator can extend into the other cavity and be connected to the condensation plate assembly, the condensation plate assembly includes a plurality of condensation plates, and the plurality of condensation plates can be configured to form an incident hole with a variable size.

[0005] By enabling the formation of incident holes of variable sizes on the condensation plate assembly, that is, being able to adjust condensation areas of different sizes, a sufficiently large condensation plate area can ensure that water vapor directly condenses into ice after hitting the condensation plate, thereby increasing the water vapor extraction speed and the efficiency of water vapor removal.

[0006] As a preferred technical solution, a channel is provided on the top of the shell, and a driving motor is fixedly connected to the inner wall of the channel. The driving motor can drive the plurality of condensation plates to rotate and cause the condensation areas formed by the plurality of condensation plates to increase or decrease.

[0007] As a preferred technical solution, the condensation plate assembly includes a front panel and a rear panel, the front panel is fixed to the primary cold head of the refrigerator through a connecting plate, one end of the condensation plate is rotatably connected to the front panel, and the other end of the condensation plate is slidably matched with the rear panel, a ring gear is fixedly connected to the rear panel, and the output end of the drive motor is transmission-connected to a gear that cooperates with the ring gear.

[0008] As a preferred technical solution, one side of the condensation plate is fixedly connected with a first connecting shaft and is rotationally connected to the front panel through the first connecting shaft. The other side of the condensation plate is fixedly connected with a second connecting shaft. The second connecting shaft has a T-shaped structure, and a connecting groove adapted to the second connecting shaft is formed on the rear panel.

[0009] As a preferred technical solution, a limiting block is fixedly connected to the free end of the second connecting shaft, and the shape of the connecting groove is adapted to the limiting block.

[0010] As a preferred technical solution, one end of the channel is connected to a flap valve, and the other end is connected to a molecular pump. The condensation plate assembly is coaxial with the axis of the molecular pump.

[0011] As a preferred technical solution, a connecting hole adapted to the first connecting shaft is formed on the front panel, and the connecting hole is rotationally matched with the first connecting shaft.

[0012] As a preferred technical solution, a gap is left between the outer wall of the condensation plate assembly and the inner wall of the outer shell cavity.

[0013] As a preferred technical solution, a plurality of the condensation plates are arranged at equal angles along the circumferential direction of the condensation plate assembly, and the condensation plates are arc-shaped.

[0014] As a preferred technical solution, a relief groove is formed on the condensation plate.

[0015] The beneficial effects of the present utility model are as follows:

[0016] (1) In the present utility model, by enabling the formation of incident holes with variable sizes on the condensation plate assembly, that is, the condensation areas of different sizes can be adjusted. A sufficiently large condensation plate area can ensure that water vapor directly sublimates into ice after hitting the condensation plate, thereby improving the water vapor pumping speed and the efficiency of removing water vapor.

[0017] (2) In the present utility model, by designing the thickness of the channel, that is, the connecting flange, to be thin, when it is used in series with a molecular pump, the installation space is greatly reduced; by arranging the condensation plate assembly facing the pump port, the effective impact area of gas molecules is maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a front view structural schematic diagram provided by an embodiment of the present utility model;

[0019] Figure 2 is a rear view structural schematic diagram provided by an embodiment of the present utility model;

[0020] Figure 3 is a structural schematic diagram of a connecting plate provided by an embodiment of the present utility model;

[0021] Figure 4Schematic diagram of the front panel structure provided by the embodiment of the present utility model;

[0022] Figure 5 Schematic diagram of the rear panel structure provided by the embodiment of the present utility model;

[0023] Figure 6 Schematic diagram of the connection hole structure provided by the embodiment of the present utility model;

[0024] Figure 7 Front view schematic diagram of the condensation plate provided by the embodiment of the present utility model;

[0025] Figure 8 Rear view schematic diagram of the condensation plate provided by the embodiment of the present utility model;

[0026] Figure 9 Schematic diagram of the second connection shaft cross-section on the condensation plate provided by the embodiment of the present utility model;

[0027] Figure 10 Schematic diagram of the connection groove structure provided by the embodiment of the present utility model;

[0028] Figure 11 Schematic diagram of the connection groove cross-section provided by the embodiment of the present utility model;

[0029] Reference numerals: 1, housing; 2, GM refrigerator; 3, condensation plate assembly; 31, front panel; 311, connection hole; 32, condensation plate; 321, first connection shaft; 322, second connection shaft; 323, limiting block; 33, rear panel; 331, connection groove; 4, connection plate; 5, controller; 6, sensor interface; 7, vacuum gauge; 8, drive motor. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0031] Refer to Figure 1 、 Figure 2, A thin low-temperature cold trap with adjustable water vapor pumping speed, comprising: a housing 1, a GM refrigerator 2, a condensation plate assembly 3, a connecting plate 4, a controller 5, a sensor interface 6, a vacuum gauge 7, and a driving motor 8. A through channel is provided at the top of the housing 1, and the bottom is a cylindrical cavity. The channel and the cylindrical cavity are two through-connected cavity structures. The channel can be a connecting flange. Among them, one end of the channel is connected to a gate valve, and the other end is connected to a molecular pump. The cylindrical cavity forms a vacuum area for placing the GM refrigerator 2. The condensation plate assembly 3 is fixedly connected to the GM refrigerator 2 through the connecting plate 4, and the condensation plate assembly 3 is located in the channel;

[0032] Refer to Figure 3 , The connecting plate 4 includes a vertical section and a horizontal section that are vertically fixed. The first-stage cold head of the GM refrigerator 2 is fixed to the horizontal section of the connecting plate 4 and provides cooling capacity for the condensation plate assembly 3 through the connecting plate 4. The vertical section of the connecting plate 4 is fixedly connected to the condensation plate assembly 3. The controller 5, the sensor interface 6, and the vacuum gauge 7 are fixedly connected to the outside of the housing 1. The driving motor 8 is fixed inside the channel of the housing 1 and provides driving force for the opening and closing of the incident hole of the condensation plate assembly 3. Among them, the vacuum gauge 7 is used for vacuum acquisition and is electrically connected to the controller 5; A temperature sensor is fixedly connected to the first-stage cold head of the GM refrigerator 2. The connecting wires of the driving motor 8 and the temperature sensor are both electrically connected to external devices through the sensor interface 6.

[0033] Refer to Figure 4 , Figure 5 , Figure 6 , The condensation plate assembly 3 includes a front panel 31, several condensation plates 32, and a rear panel 33. The front panel 31 is fixedly connected to one end of the connecting plate 4, and the other end of the connecting plate 4 is fixedly connected to the first-stage cold head of the GM refrigerator 2. Several condensation plates 32 are rotatably connected to the front panel 31 and are arranged in a ring shape. The several condensation plates 32 are combined to form a fan blade structure with a closed central area in the closed state, so as to configure and form an incident hole of the condensation plate assembly 3 with variable dimensions. A toothed ring is fixedly connected to the rear panel 33. The output end of the driving motor 8 is fixedly connected to a gear and can drive the gear to rotate around its axis. The gear meshes with the toothed ring, so the driving motor 8 can drive the rear panel 33 to rotate;

[0034] Refer to Figure 7 , Figure 8 , Figure 9, one end of one side of the condensation plate 32 is fixedly connected with a first connecting shaft 321, and the other end of the other side is fixedly connected with a second connecting shaft 322. A connecting hole 311 adapted to the first connecting shaft 321 is formed on the front panel 31. The connecting hole 311 is a round hole. The first connecting shaft 321 is rotationally matched with the connecting hole 311. To prevent the first connecting shaft 321 from disengaging from the connecting hole 311, the first connecting shaft 321 can be rotationally connected with the connecting hole 311 through a bearing. The first connecting shaft 321 and the second connecting shaft 322 are respectively located on both sides of the condensation plate 32. A connecting groove 331 adapted to the second connecting shaft 322 is formed on the rear panel 33. The second connecting shaft 322 and the connecting groove 331 are in sliding fit. To prevent the second connecting shaft 322 from disengaging from the connecting groove 331, the shape of the connecting groove 331 is adapted to the second connecting shaft 322 to ensure that the second connecting shaft 322 cooperates with the connecting groove 331 during rotation. Refer to Figure 10 , Figure 11 , both the cross-sections of the connecting groove 331 and the second connecting shaft 322 are arranged in a T shape. On the one hand, the heat transfer area is increased. On the other hand, it can prevent the rear panel 33 from detaching from the condensation plate assembly 3. The connecting groove 331 includes a horizontal part and a vertical part. The vertical part is in sliding fit with the second connecting shaft 322. One end of the second connecting shaft 322 extending into the connecting groove 331 is also fixedly connected with a limiting block 323. The limiting block 323 is located in the horizontal part;

[0035] It should be noted that in this embodiment, ten condensation plates 32 are provided and are evenly distributed at equal angles along the circumferential direction of the front panel 31; the ten condensation plates 32 are staggeredly distributed in their axial directions to prevent interference during rotation. Therefore, the lengths of the first connecting shaft 321 and the second connecting shaft 322 are different; through holes are formed on both the front panel 31 and the rear panel 33, and gaps are left between both the front panel 31 and the rear panel 33 and the inner wall of the housing 1 to ensure thermal insulation;

[0036] The driving motor 8 can drive the rear panel 33 to rotate through the gear and ring gear transmission; the first connecting shaft 321 is rotationally matched with ten connecting holes 311 on the front panel as the rotation axis respectively, and the second connecting shaft 322 is matched with the connecting groove 331 on the rear panel 33. The ten condensation plates 32 slide in the connecting groove 331 as the rear panel 33 rotates, thereby realizing the adjustment of the size of the incident hole.

[0037] The driving motor 33 can drive the condensation plates 32 to rotate synchronously clockwise or counterclockwise to ensure that the incident hole is synchronously enlarged or reduced by the rotation of several condensation plates 32; to increase the rotation area of the condensation plates 32 to ensure that the condensation area is as large as possible, and at the same time prevent interference between the first connecting shafts 321 and the second connecting shafts 322 of different condensation plates 32, a relief groove is formed on the outer edge of the arc-shaped area of the condensation plates 32;

[0038] At the initial position, the angle of each condensation plate 32 is 0°. At this time, the incident hole is the largest and the adsorption area is the smallest. When the condensation plate 32 rotates to a certain angle, the through hole at its center becomes smaller. At this time, the incident hole is the smallest and the adsorption area is the largest. After the water vapor molecules hit the condensation plate 32, they directly sublimate into ice. At this time, a partial area of one end of any condensation plate 32 away from the connecting shaft 321 blocks a partial area of the corresponding end of the adjacent condensation plate 32; since the area of the incident hole formed by the condensation plate 32 decreases and the condensation area formed by multiple condensation plates 32 increases, the water vapor pumping speed can be increased.

[0039] The thickness of the connecting flange is 50 mm. Through this design, when it is used in series with the molecular pump, the installation space is greatly reduced; in addition, the condensation plate assembly 3 with a thin structure faces the pump port, that is, the condensation plate assembly 3 is coaxial with the axis of the molecular pump, and the effective impact area of gas molecules is the largest.

[0040] When the thin-type cryogenic cold trap and the molecular pump are used in series, on the one hand, it is necessary to ensure a sufficiently large gas conductance so as not to affect the normal pumping speed of the molecular pump. On the other hand, a sufficiently large condensation plate is required to increase the water vapor pumping speed. The cryogenic cold trap with adjustable water vapor pumping speed can solve the contradictory relationship between the two in a limited space. When the molecular pump is just turned on, the area of the condensation region formed by the cold trap condensation plate 32 is adjusted to be small to ensure a large conductance and quickly pump out other gases except water vapor. After pumping for a period of time, the area of the condensation region formed by the cold trap condensation plate 32 is adjusted to be large to increase the pumping speed of water vapor.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thin cryogenic cold trap with adjustable water vapor extraction speed, characterized in that: It includes a shell, a condensation plate assembly, and a refrigerator. The shell is provided with two mutually interpenetrating cavity structures, one of the cavities is provided with a refrigerator, and the other cavity is provided with a condensation plate assembly. The connecting plate on the first-level cold head of the refrigerator can extend into the other cavity and be connected to the condensation plate assembly. The condensation plate assembly includes a plurality of condensation plates, and the plurality of condensation plates can be configured to form an incident hole with variable size.

2. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 1, characterized in that: A channel is provided on the top of the shell, and a driving motor is fixedly connected to the inner wall of the channel. The driving motor can drive the plurality of condensation plates to rotate and cause the condensation areas formed by the plurality of condensation plates to increase or decrease.

3. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 2, characterized in that: The condensation plate assembly includes a front panel and a rear panel, the front panel is fixed to the primary cold head of the refrigerator through a connecting plate, one end of the condensation plate is rotatably connected to the front panel, and the other end of the condensation plate is slidably matched with the rear panel, a gear ring is fixedly connected to the rear panel, and the output end of the drive motor is transmission-connected to a gear that cooperates with the gear ring.

4. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 3, characterized in that: One side of the condensation plate is fixedly connected with a connecting shaft 1 and is rotatably connected to the front panel through the connecting shaft 1. The other side of the condensation plate is fixedly connected with a connecting shaft 2, and the connecting shaft 2 is a T-shaped structure. The rear panel is provided with a connecting groove that is compatible with the connecting shaft 2.

5. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 4, characterized in that: The free end of the second connecting shaft is fixedly connected to the limiting block, and the shape of the connecting groove is adapted to the limiting block.

6. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 2, characterized in that: One end of the channel is connected to the plug valve, and the other end is connected to the molecular pump. The condensation plate assembly is coaxial with the axis of the molecular pump.

7. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 4, characterized in that: The front panel is provided with a connection hole matched with the connection shaft 1, and the connection hole and the connection shaft 1 are rotatably matched.

8. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 1, characterized in that: A gap is left between the outer wall of the condensation plate assembly and the inner wall of a cavity of the shell.

9. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 1, characterized in that: The plurality of condensation plates are distributed at equal angles along the circumference of the condensation plate assembly, and the condensation plates are arranged in an arc shape.

10. A thin cryogenic cold trap with adjustable water vapor extraction speed according to claim 1, characterized in that: The condensation plate is provided with an avoidance groove.

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