Molecular pump

Abstract

The invention relates to the technical field of vacuum equipment, and discloses a molecular pump which comprises a shell provided with a mounting cavity. The medium channel is arranged on the shell, one end of the medium channel is communicated with the outside of the shell, the other end of the medium channel is communicated with the installation cavity, the medium channel is filled with water absorption materials, an outlet and an inlet of the medium channel are provided with switch structures, and the vacuumizing opening is formed in the shell and communicated with the cavity. According to the technical scheme, the switch structure at the inlet is opened, cooling water is introduced into the medium channel and absorbed by the water absorption material in the medium channel, after the water absorption material absorbs enough cooling water, the switch structure at the inlet is closed, the switch structure at the outlet is opened, the water absorption material is exposed in a negative pressure environment, the boiling point of the cooling water is reduced, and the cooling water is cooled. And water vapor generated after the cooling water is evaporated is discharged out of the mounting cavity through the vacuumizing opening. A large amount of heat is taken away while the water vapor is evaporated, the temperature of the water absorbing material is rapidly reduced, and then the core part of the molecular pump is cooled.

Description

Technical Field

[0001] This invention relates to the field of vacuum equipment technology, and more specifically to a molecular pump. Background Technology

[0002] Molecular pumps, as core components in semiconductor equipment, provide a vacuum and clean environment for the process chamber. During long-term operation, magnetically levitated molecular pumps generate significant heat due to the operation of the motor and magnetic bearings. This accumulated heat accelerates the aging of core components and reduces the pump's lifespan. Currently, most molecular pumps use embedded water-cooling pipes to cool the pump. However, the cooling efficiency of these pipes is affected by factors such as contact area, cooling water temperature, and pressure, resulting in low efficiency and significant fluctuations. Summary of the Invention

[0003] This invention provides a molecular pump to solve the technical problem in the prior art where the cooling efficiency of the water-cooled pipe in the molecular pump is affected by factors such as contact area, cooling water temperature and pressure, resulting in low cooling efficiency and large fluctuations.

[0004] In a first aspect, the present invention provides a molecular pump, including a housing having an installation cavity; a medium channel disposed on the housing, one end of the medium channel communicating with the outside of the housing, the other end of the medium channel communicating with the installation cavity, the medium channel being filled with an absorbent material, and both the outlet and inlet of the medium channel being provided with a switch structure; a vacuum port disposed on the housing and communicating with the installation cavity.

[0005] The above technical solution first opens the inlet switch structure of the medium channel, allowing cooling water to flow into the medium channel and be absorbed by the water-absorbing material. Once the water-absorbing material has absorbed enough cooling water, the inlet switch structure is closed, and the outlet switch structure is opened. The cooling water in the water-absorbing material is exposed to a negative pressure environment, lowering its boiling point and causing it to evaporate faster. The evaporated water vapor is then discharged from the installation cavity through the vacuum port. The evaporation of the water vapor carries away a large amount of heat, rapidly reducing the temperature of the water-absorbing material. Through heat conduction, the outer shell temperature decreases rapidly, thereby reducing the temperature of components such as the bearing housing, motor, magnetic bearing, and sensor inside the molecular pump, effectively cooling the core components of the molecular pump. Therefore, the technical solution of this embodiment solves the problem in the prior art where the cooling efficiency of water-cooled pipes is affected by factors such as contact area, cooling water temperature, and pressure, resulting in low cooling efficiency and large fluctuations.

[0006] Optionally, the outer casing includes a pump housing and a base disposed at the end of the pump housing. The medium channel includes a connecting hole and a delivery pipe. The connecting hole is disposed on the base, with a first end communicating with the mounting cavity and a second end penetrating the end face of the base facing the outer casing. The delivery pipe is disposed between the pump housing and the base and is inserted into the second end of the connecting hole.

[0007] Furthermore, the housing also includes a mounting ring, which is disposed between the pump housing and the base. The mounting ring has a mounting hole, and the delivery pipe is fixed in the mounting hole.

[0008] Optionally, the mounting hole is bent, the delivery pipe is bent, the first end of the mounting hole passes through the end face of the mounting ring facing the base, the second end of the mounting hole passes through the outer side of the mounting ring, and the first end of the mounting hole is connected to the second end of the connecting hole.

[0009] Furthermore, an annular protrusion is provided on the end face of the base, and an annular recess is provided on the end face of the mounting ring facing the base. The annular protrusion is embedded in the annular recess, and there is a gap between the top of the annular protrusion and the bottom of the annular recess. A connecting hole communicates with the annular recess, and a conveying pipe extends into the annular recess. The connecting hole passes through the annular recess.

[0010] Optionally, the top of the annular protrusion is provided with a recessed platform, and a connecting hole is provided in the recessed platform, into which the end of the conveying pipe is inserted.

[0011] Furthermore, an annular positioning step is provided on the outer side of the mounting ring, and the end of the pump casing mates with the annular positioning step.

[0012] Optionally, a first sealing ring is provided between the mounting ring and the pump housing, and a second sealing ring is provided between the mounting ring and the base.

[0013] Furthermore, the switching structure includes a first solenoid valve disposed at the end of the delivery pipe opposite to the connecting hole and a second solenoid valve disposed at the first end of the connecting hole.

[0014] Optionally, the absorbent material can be made of absorbent resin.

[0015] Beneficial effects: By reducing the vacuum level inside the molecular pump cavity, the boiling point of the cooling water is lowered, making it easier for the cooling water to evaporate, resulting in lower water vapor temperature under low pressure. The evaporation of the cooling water carries away a large amount of heat, reducing the temperature of the absorbent material, and consequently lowering the temperature of the base and mounting ring. Through the principle of heat transfer, the temperature of core components inside the molecular pump, such as the bearing housing and motor, is reduced. The flow rate of the cooling water is controlled by a control switch structure, minimizing temperature fluctuations. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a cross-sectional view of a molecular pump according to an embodiment of the present invention; Figure 2 for Figure 1 A cross-sectional view of the molecular pump base shown; Figure 3 for Figure 2 A magnified view of the mounting ring in the middle.

[0018] Explanation of reference numerals in the attached figures: 1. Outer shell; 101. Mounting cavity; 102. Pump casing; 103. Base; 1031. Annular protrusion; 104. Mounting ring; 1041. Annular recess; 1042. Positioning step; 2. Medium channel; 201. Connecting hole; 2011. First end of the connecting hole; 2012. Second end of the connecting hole; 202. Delivery pipe; 203. Annular pipe; 3. Switch structure; 301, First solenoid valve; 302, Second solenoid valve; 4. Vacuum port; 5. First sealing ring; 6. Second sealing ring. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Molecular pumps, as core components in semiconductor equipment, provide a vacuum and clean environment for the process chamber. During long-term operation, magnetically levitated molecular pumps generate significant heat due to the operation of the motor and magnetic bearings. This accumulated heat accelerates the aging of core components and reduces the pump's lifespan. Currently, most molecular pumps use embedded water-cooling pipes to cool the pump. However, the cooling efficiency of traditional water-cooling pipes is affected by factors such as contact area, cooling water temperature, and pressure, resulting in low cooling efficiency.

[0021] like Figure 1 As shown, according to an embodiment of a molecular pump provided by the present invention, a housing 1 is included, the housing 1 having a mounting cavity 101; a medium channel 2 is disposed on the housing 1, one end of the medium channel 2 is connected to the outside of the housing 1, and the other end of the medium channel 2 is connected to the mounting cavity 101; the medium channel 2 is filled with a water-absorbing material; a switch structure 3 is provided at both the outlet and the inlet of the medium channel 2; and a vacuum port 4 is disposed on the housing 1, the vacuum port 4 being connected to the mounting cavity 101.

[0022] Through the technical solution of the above embodiment, firstly, the switch structure 3 at the inlet of the medium channel 2 is opened, and cooling water is introduced into the medium channel 2 and absorbed by the water-absorbing material in the medium channel 2. When the water-absorbing material has absorbed enough cooling water, the switch structure 3 at the inlet of the medium channel 2 is closed, and the switch structure 3 at the outlet of the medium channel 2 is opened. The cooling water in the water-absorbing material is exposed to a negative pressure environment, the boiling point of the cooling water decreases, and the cooling water evaporates faster in the low-pressure environment, and the water vapor temperature is also low. The evaporated water vapor is discharged into the installation cavity 101 through the vacuum port 4. While the water vapor evaporates, it takes away a large amount of heat, and the temperature of the water-absorbing material drops rapidly. Through the principle of heat conduction, the temperature of the outer shell 1 drops rapidly, thereby reducing the temperature of components such as the bearing seat, motor, magnetic bearing, and sensor inside the molecular pump, and cooling the core components of the molecular pump. Therefore, the technical solution of this embodiment solves the technical problem of low cooling efficiency caused by traditional water pipe cooling in the prior art.

[0023] like Figure 1 , Figure 2 As shown, an embodiment of the molecular pump provided by the present invention includes a housing 1, which has a mounting cavity 101. A bearing seat is disposed within the mounting cavity 101, and a turbine is placed in the middle of the bearing seat. The bearing seat contains various structures such as a motor and a magnetic bearing. All components together drive the turbine to perform radial suspension and rotational motion. The turbine's motion directionally drives gas to flow towards the vacuum port 4, thereby forming a vacuum environment. During this process, the turbine, bearing seat, motor, and other components generate a large amount of heat.

[0024] Furthermore, the vacuum port 4 is used to connect to an external vacuum pumping device.

[0025] Medium channel 2 is installed on the outer casing 1. Medium channel 2 is a "Z"-shaped channel, with one end connected to the outside of the outer casing 1 and the other end connected to the mounting cavity 101 of the outer casing 1. The "Z"-shaped channel is filled with absorbent material, which can repeatedly absorb and release water. Both the inlet and outlet of medium channel 2 are equipped with switch structures 3, with the switch structure 3 at the inlet of medium channel 2 connected to the chiller.

[0026] During cooling, the inlet switch 3 of the medium channel 2 is first opened and the outlet switch 3 is closed via electrical control, allowing water from the chiller to flow into the medium channel 2. The absorbent material absorbs the incoming water. After absorption, the inlet switch is closed and the outlet switch 3 of the medium channel 2 is opened. The mechanical pump connected to the vacuum port 4 draws the pressure at the outlet of the medium channel 2 to a negative pressure. Due to the reduced pressure, the boiling point of the water in the absorbent material decreases, causing it to evaporate rapidly. The low-temperature water vapor absorbs heat and cools down, then the resulting water vapor is discharged from the mounting cavity 101 through the vacuum port 4.

[0027] A vacuum port 4 is located on the outer casing 1 and is fixedly connected to it. In this embodiment, the vacuum port 4 and the outer casing 1 are fixedly connected by screws and bolts. One end of the vacuum port 4 is connected to the mounting cavity 101, and the other end is connected to a mechanical pump. The end of the vacuum port 4 connected to the mounting cavity 101 has a protruding structure, and the outer casing 1 has a recess that mates with the protruding structure. The vacuum port is mounted and positioned on the outer casing 1 through the mating of the protruding structure and the recess. The other end of the vacuum port 4 has a mounting flange structure, and the vacuum port 4 is fixedly connected to the mechanical pump through the mounting flange structure. The mechanical pump provides a vacuum or low-pressure environment for the mounting cavity 101. The mechanical pump can also extract and remove water vapor from the mounting cavity 101. By controlling the power of the mechanical pump, it is ensured that all evaporated water vapor is extracted, preventing water vapor from entering the components and causing damage.

[0028] Optional, such as Figure 2 , Figure 3 As shown, the outer casing 1 includes a pump housing 102 and a base 103, with the base 103 located at the bottom of the pump housing 102. The medium channel 2 includes a connecting hole 201 and a delivery pipe 202. The connecting hole 201 is an "L"-shaped hole, containing a water-absorbing material tube. The connecting hole 201 is located on the base 103, with its first end 2011 communicating with the mounting cavity 101 and connected to a switch structure 3. The second end 2012 of the connecting hole extends through the end face of the base 103 facing the outer casing. The delivery pipe 202 consists of multiple circular pipes connected by an annular circular pipe 203, with the lower end of each delivery pipe inserted into the second end 2012 of the connecting hole.

[0029] In this embodiment, the pump housing 102 and the base 103 are fixedly connected by screws and bolts. The pump housing 102 is placed on the base 103, and the base 103 is provided with a positioning interface that cooperates with the pump housing 102. The base 103 is placed on the positioning interface, and then the pump housing 102 and the base 103 are fixedly connected by screws and bolts to complete the assembly process. The inner diameter of the delivery pipe 202 is slightly larger than the diameter of the connecting hole 201. The lower end of the delivery pipe 202 is inserted into the second end 2012 of the connecting hole, and then the pump housing 102 presses the delivery pipe 202 tightly onto the base 103 to complete the assembly between the delivery pipe and the connecting hole.

[0030] Furthermore, the outer casing 1 also includes a mounting ring 104. The mounting ring has an annular structure and is fixedly disposed between the pump casing 102 and the base 103. The mounting ring 104 has a mounting hole, and the delivery pipe 202 is fixed in the mounting hole. In one embodiment of the present invention, the delivery pipe 202 is embedded in the mounting hole of the mounting ring 104, and the mounting ring 104 fixes the delivery pipe 202 inside the outer casing 1, preventing the mounting ring 104 from shifting or loosening due to vibrations generated during the operation of the molecular pump. The present invention, through the fixed connection between the pump casing 102, the mounting ring 104, and the base 103, together constitutes a sealed mounting cavity 101.

[0031] In this embodiment, the mounting ring 104 is disposed between the pump housing 102 and the base 103. The upper part of the mounting ring 104 has a positioning structure that mates with the pump housing 102, and the lower part of the mounting ring 104 has a positioning structure that mates with the base 103. During installation, the pump housing 102 is first placed on the positioning structure on the upper part of the mounting ring 104, and then tightened using threads and screws. Next, the installed pump housing 102 and mounting ring 104 are placed on the positioning structure of the base 103, and the screws and bolts are tightened to complete the positioning installation.

[0032] Optionally, the mounting hole is bent, the conveying pipe 202 is bent, the opening of the conveying pipe 202 is bent downward, the first end of the mounting hole passes through the end face of the mounting ring 104 facing the base 1, the second end of the mounting hole passes through the outer side of the mounting ring 104, the first end of the mounting hole is connected to the second end of the connecting hole, and the bending shape of the mounting hole matches the bending shape of the conveying pipe 202, so that the conveying pipe 202 can be easily embedded into the mounting hole.

[0033] The mounting hole is divided into a horizontal section and a vertical section. One end of the horizontal section faces the inside of the mounting cavity 1, and the other end is connected to the vertical section. The horizontal section is perpendicular to the vertical section, and the other end of the vertical section is connected to the conveying pipe 202. In another embodiment of the present invention, the mounting ring 104 presses the conveying pipe 202 tightly onto the base 103. Through the fixed connection between the mounting ring 104 and the base 103, the conveying pipe 202 is fixedly embedded in the mounting ring 104.

[0034] Furthermore, such as Figure 3 As shown, in another embodiment of the present invention, an annular protrusion 1031 is provided on the upper end face of the base 103, and the annular protrusion is provided on the edge of the base 103. An annular recess 1041 is provided on the end face of the mounting ring 104 facing the base. During installation, the annular recess 1041 cooperates with the annular protrusion 1031, and the annular protrusion 1031 is embedded in the annular recess 1041, thereby positioning and installing the mounting ring 104 onto the base 103. A gap is provided between the top end of the annular recess 1041 and the bottom end of the annular protrusion 1031, which facilitates the connection between the downward bending portion of the conveying pipe 202 and the connecting hole 201. The width of the annular protrusion 1031 and the annular recess 1041 is wider than the outer diameter of the conveying pipe 202. The connecting hole 201 is connected to the gap between the annular recess 1041 and the annular protrusion 1031. The conveying pipe 202 passes through the outside of the mounting ring 104 and extends into the annular recess 1041. The connecting hole 201 passes through the annular protrusion 1031 and extends to the gap. With this design, the mounting ring 104 can press and fix the conveying pipe 202 to the base 103, and the positioning structure also makes it convenient to install the mounting ring on the base 103.

[0035] Optionally, a recessed platform is provided at the top of the annular protrusion 1031. The width of the recessed platform is slightly wider than the outer diameter of the conveying pipe 202, and the conveying pipe 202 can be just inserted into the recessed platform. A connecting hole 201 is provided in the recessed platform, and the upper end of the connecting hole 201 communicates with the recessed platform. The recessed platform can position and connect the lower end of the conveying pipe 202 with the upper end of the connecting hole 201, thereby aligning the conveying pipe 202 with the connecting hole 201 and increasing the stability of the conveying pipe 202 in the pump casing 1.

[0036] When installing the conveying pipe 202, align the lower end of the conveying pipe 202 and insert it into the recessed platform, and then fix the mounting ring 104 onto the mounting base 103 to complete the assembly.

[0037] Furthermore, such as Figure 1 , Figure 3As shown, in another embodiment of the present invention, the outer diameter of the upper part of the mounting ring 104 is the same as the outer diameter of the pump housing 102. The top of the mounting ring 104 is flush, and the outer side has two "L"-shaped steps, smaller at the upper end and larger at the lower end, which together form an annular positioning step 1042. The lower end of the pump housing 102 can be placed on the positioning step 1042, and the inner side of the lower end of the pump housing 102 is provided with a recess that matches the annular positioning step 1042. When the pump housing 102 is placed on the mounting ring 104, the recess on the inner side of the pump housing 102 is tightly attached to the annular positioning step 1042. The outer side of the pump housing 102 and the outer side of the mounting ring 104 are flush in the vertical direction. The mounting ring 104 and the pump housing 102 are then fixed with screws and bolts, so that the pump housing 102 can be successfully positioned and installed on the mounting ring 104, ensuring that the mounting ring 104 and the pump housing 102 are flush vertically. After installation and positioning, the mounting ring 104 can press and fix the delivery pipe 202 inside the housing 1, ensuring the stability of the delivery pipe 202 inside the housing 1. The mounting ring 104 can fix the pump housing 102 and the base 103 together, and the mounting ring 104, the pump housing 102 and the base 103 are fixedly connected together to form a sealed installation cavity 101.

[0038] Optional, such as Figure 3 As shown, in this embodiment, a first sealing ring 5 is provided between the mounting ring 104 and the pump housing 102. The first sealing ring 5 is vertically positioned at the annular positioning step 1042. The first sealing ring 5 seals the gap between the mounting ring 104 and the pump housing 102, protecting the pressure inside the molecular pump cavity. A second sealing ring 6 is directly provided between the mounting ring 104 and the base 103. The second sealing ring 6 is horizontally placed between the mounting ring 104 and the base 103. The second sealing ring 6 can ensure the sealing between the mounting ring 104 and the base 103, and also ensure that the mounting ring 104 can press the delivery pipe 202 tightly.

[0039] Furthermore, such as Figure 2As shown, the switch structure 3 includes a first solenoid valve 301 disposed at one end of the delivery pipe 202 away from the connecting hole 201. The other end of the first solenoid valve 301 is connected to a chiller to provide chilled water for the water absorption medium. When the pressure in the medium channel 2 is fixed and the inner diameter of the delivery pipe 202 is fixed, the amount of water absorption medium entering is positively correlated with the water supply time of the chiller. By controlling the opening and closing of the first solenoid valve 301, the water supply time of the chiller is controlled, ensuring that the amount of cooling water entering the medium channel 2 is fixed, so that the water absorption medium is filled with sufficient cooling water, while ensuring that no excess water flows into the cavity of the molecular pump and causes damage to the internal components. The switching structure 3 also includes a second solenoid valve 302. One end of the second solenoid valve 302 is connected to the first end 2011 of the connecting hole, and the other end is connected to the cavity of the pump housing. When the water-absorbing medium absorbs enough cooling water, the first solenoid valve 301 is closed. After the controller detects that the first solenoid valve 301 is closed, the second solenoid valve 302 is opened, and the cooling medium is exposed to a negative pressure environment. Under low pressure conditions, the boiling point of the cooling water is greatly reduced, and a large amount of cooling water evaporates. The water vapor is discharged from the cavity through the vacuum port 4. As the water vapor evaporates, it carries away a large amount of heat, and the temperature of the water-absorbing material drops rapidly. Through the principle of heat conduction, the temperature of the bottom sleeve drops rapidly, thereby reducing the temperature of components such as the bearing seat, motor, magnetic bearing, and sensor inside the molecular pump. This cools the core components of the molecular pump and improves the stability of the molecular pump operation.

[0040] Optionally, in another embodiment of the present invention, the absorbent material is made of a water-absorbing resin. The water-absorbing resin has the characteristics of being able to repeatedly absorb and release water. In addition, the water-absorbing resin has good water absorption performance and can absorb water many times its own volume. It also has good thermal conductivity, which can cool down the core components inside the molecular pump more quickly and effectively.

[0041] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A molecular pump, characterized in that, include: The outer casing (1) has a mounting cavity (101); A medium channel (2) is provided on the outer shell (1). One end of the medium channel (2) is connected to the outside of the outer shell (1), and the other end is connected to the mounting cavity (101). The medium channel (2) is filled with absorbent material. Both the inlet and outlet of the medium channel (2) are provided with a switch structure (3). A vacuum port (4) is provided on the outer shell (1) and communicates with the mounting cavity (101).

2. The molecular pump according to claim 1, characterized in that, The outer casing (1) includes a pump casing (102) and a base (103) disposed at the end of the pump casing (102). The medium channel (2) includes a connecting hole (201) and a delivery pipe (202). The connecting hole (201) is disposed on the base (103). The first end (2011) of the connecting hole is connected to the mounting cavity (101). The second end (2012) of the connecting hole passes through the end face of the base (103) facing the outer casing (1). The delivery pipe (202) is disposed between the pump casing (102) and the base (103). The delivery pipe (202) is inserted into the second end (2012) of the connecting hole.

3. The molecular pump according to claim 2, characterized in that, The outer casing (1) also includes a mounting ring (104), which is disposed between the pump casing (102) and the base (103). The mounting ring has a mounting hole, and the delivery pipe (202) is fixed in the mounting hole.

4. The molecular pump according to claim 3, characterized in that, The mounting hole is bent, the conveying pipe (202) is bent, the first end of the mounting hole passes through the end face of the mounting ring (104) facing the base (103), the second end of the mounting hole passes through the outer side of the mounting ring (104), and the first end of the mounting hole is connected to the second end (2012) of the connecting hole.

5. The molecular pump according to claim 4, characterized in that, An annular protrusion (1031) is provided on the end face of the base (103), and an annular recess (1041) is provided on the end face of the mounting ring (104) facing the base (103). The annular protrusion (1031) is embedded in the annular recess (1041), and there is a gap between the top of the annular protrusion (1031) and the bottom of the annular recess (1041). A connecting hole (201) communicates with the annular recess (1041), and a conveying pipe (202) extends into the annular recess (1041). The connecting hole (201) passes through the annular recess (1041).

6. The molecular pump according to claim 5, characterized in that, The top of the annular protrusion (1031) is provided with a recessed platform, and a connecting hole (201) is provided in the recessed platform. The end of the conveying pipe (202) is inserted into the recessed platform.

7. The molecular pump according to claim 3, characterized in that, An annular positioning step (1042) is provided on the outer side of the mounting ring (104), and the end of the pump casing (102) is engaged with the annular positioning step (1042).

8. The molecular pump according to claim 3, characterized in that, A first sealing ring (5) is provided between the mounting ring (104) and the pump housing (102), and a second sealing ring (6) is provided between the mounting ring (104) and the base (103).

9. The molecular pump according to any one of claims 2 to 7, characterized in that, The switch structure (3) includes a first solenoid valve (301) disposed at one end of the delivery pipe (202) away from the connecting hole (201) and a second solenoid valve (302) disposed at the first end (2011) of the connecting hole.

10. The molecular pump according to any one of claims 1 to 8, characterized in that, The absorbent material is made of absorbent resin.

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