Cryopump heating device

Abstract

The utility model relates to a cryopump heating device which further comprises a heat pipe and a heater, the heat pipe penetrates through a cryopump, the heat pipe is in contact with a primary cold head and a secondary cold head in the cryopump, and the heater is located outside the cryopump and is in contact with the heat pipe. The heater is arranged on the outer side of the low-temperature pump, enough space is reserved between the heater and the heat pipe for insulation treatment, normal work of the low-temperature pump is prevented from being affected by short circuit of a heating rod in the prior art, and reliability of the low-temperature pump is improved. The heat insulation sleeve is used for heat insulation of the heat pipe and the heater, and heat exchange between the heat pipe and the outside is reduced when the low-temperature pump adsorbs the heat pipe at low temperature and the low-temperature pump heats up.

Description

Technical Field

[0001] The utility model relates to the field of cryogenic pumps, in particular to a cryogenic pump heating device. Background Art

[0002] Cryopumps are storage vacuum pumps with an extremely low-temperature surface inside the pump that captures gases through condensation and adsorption, achieving an ultra-high vacuum state. They can achieve a clean vacuum with the highest pumping rate and the lowest ultimate pressure. They 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, and space simulation devices.

[0003] When a cryopump reaches saturation capacity after long-term operation, its pumping speed drops dramatically. At this point, the pump needs to be stopped and heated to release the gas adsorbed on the cryopanel, restoring its original pumping performance. Heating the temperature and using a pre-pump to remove the condensed and adsorbed gas is called "regeneration."

[0004] There are several ways to regenerate:

[0005] ① Natural heating method: Turn off the power of the refrigerator and use the heat of the pump wall to slowly heat up the cryopump. The temperature rise is very slow at the beginning. When the pressure in the pump rises to the point where convection heat transfer takes effect, the temperature rise rate accelerates and finally reaches a stable temperature value.

[0006] ② Venting and heating method: After stopping the refrigerator, open the vent valve to let in clean and dry air to quickly heat up the cryopump cryopanel

[0007] ③ Electric heating method: Electric heaters are installed on the first and second stage cold heads in the cryopump. During regeneration, electric heating is applied to quickly heat up the cryopanel, thus shortening the regeneration time.

[0008] The existing electric heating method uses an electric heating rod with a metal shell that penetrates into the interior of the cryopump. Inside the empty metal shell are multiple heating wires and silicone. The silicone is located between the heating wires and the metal shell to prevent the heating wires from contacting each other or the heating rod shell, thereby preventing short circuits.

[0009] The thinner the silicone, the better the thermal conductivity, but the heater rod is more susceptible to short circuits. The thicker the silicone, the less likely it is to short, but the thermal conductivity deteriorates. Because silicone's poor thermal conductivity and the thickness of the silicone in existing heater rods are large, the heater rod's ability to heat the cold head cannot be further increased, and the regeneration time required for electric heating is prolonged. Furthermore, due to the limited space within the cryopump and the need to minimize the number of sealing interfaces, increasing the heating capacity by simply adding heater rods is not an option. Utility Model Content

[0010] The utility model provides a low-temperature pump heating device, which solves the above technical problems.

[0011] A cryopump heating device comprises a heat pipe and a heater. The heat pipe passes through the cryopump and contacts a primary cold head and a secondary cold head inside the cryopump. The heater is located outside the cryopump and contacts the heat pipe.

[0012] Furthermore, a portion of the heat pipe extending out of the cryopump is formed with a flat plate portion, the heater is in contact with the flat plate portion, and the heater is an electric heater.

[0013] Furthermore, it also includes a first fixing device and a second fixing device, the first fixing device fixes the heat pipe to the first-level cold head, and the second fixing device fixes the heat pipe to the second-level cold head.

[0014] Furthermore, the heat pipe is fixedly connected to the cylinder housing, and the heater is fixedly connected to the heat pipe.

[0015] Furthermore, the shell of the heat pipe is made of aluminum, copper, aluminum alloy or copper alloy, a capillary structure is provided in the shell of the heat pipe, and the heat pipe is filled with a working fluid.

[0016] Furthermore, the melting point of the working fluid in the heat pipe is lower than -100°C and the critical temperature is higher than 0°C.

[0017] Furthermore, the working fluid is ethanol, R23, ‌R508B or R600a.

[0018] Furthermore, it also includes a heat insulation sleeve, which is sleeved on the outside of the heat pipe and the heater.

[0019] Furthermore, it also includes a thermal insulation layer, which covers the portion of the heat pipe extending out of the cryopump and the surface of the heater, and the thermal insulation sleeve is located outside the thermal insulation layer.

[0020] Furthermore, the heat-insulating layer is a silicone sleeve or a heat-insulating coating.

[0021] The utility model has the following advantages:

[0022] 1. Heat conduction through heat pipes allows the heater to be located outside the cryopump, allowing for the installation of a heater with a larger area and power, increasing the amount of heat supplied to the cold head per unit time, reducing regeneration time, and improving production efficiency;

[0023] 2. The heater is located outside the cryopump, and there is sufficient space between the heater and the heat pipe for insulation treatment, which avoids the short circuit of the heating rod in the existing technology affecting the normal operation of the cryopump and improves the reliability of the cryopump;

[0024] 3. Use thermal insulation sleeves to insulate the heat pipe and heater, reducing the heat exchange between the heat pipe and the outside world when the cryopump is adsorbing at low temperatures and heating at high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other implementation drawings can be derived from the provided drawings without inventive effort.

[0026] Figure 1 : Schematic diagram of the three-dimensional structure of the cryopump;

[0027] Figure 2 : Schematic diagram of the three-dimensional structure of the cryopump with some components removed;

[0028] Figure 3 : Schematic diagram of the cross-sectional structure of the cryopump;

[0029] Figure 4 :exist Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle;

[0030] Figure 5 : Cross-sectional view of the heating device. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and examples:

[0032] The following describes in detail embodiments of the present invention. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0033] In the description of this utility model, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0034] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] Example 1:

[0036] like Figures 1 to 4 As shown, this embodiment provides a cryopump heating device, which also includes a heat pipe 2 and a heater 3. The heat pipe 2 passes through the cryopump 1, and the heat pipe 2 is in contact with the first-stage cold head 14 and the second-stage cold head 15 inside the cryopump 1. The heater 3 is located outside the cryopump 1 and in contact with the heat pipe 2.

[0037] Preferably, a heat pipe 2 is used to contact the primary cold head 14 and the secondary cold head 15 of the cryopump 1 at the same time, such as Figure 2 and Figure 3 shown.

[0038] Furthermore, the portion of the heat pipe 2 extending from the cryopump 1 is formed with a flat plate portion 21, with which the heater 3, which is an electric heater, contacts. The flat plate portion 21 increases the surface area, thereby increasing the contact area with the heater 3. The flat plate portion 21 conducts a greater amount of heat per unit time, allowing the heater 3 to utilize a higher heating power.

[0039] Optionally, the heat pipe 2 is fixed to the primary cold head 14 by brazing, and the heat pipe 2 is fixed to the secondary cold head 15 by brazing.

[0040] Optionally, a first fixing device 4 and a second fixing device 5 are further included, wherein the first fixing device 4 fixes the heat pipe 2 to the first-level cold head 14 , and the second fixing device 5 fixes the heat pipe 2 to the second-level cold head 15 .

[0041] Preferably, if Figure 2 and Figure 3 As shown, the first fixing device 4 and the second fixing device 5 can be a fixing block or a clamp. The fixing block is fixedly connected to the cold head by screws; the clamp tightens the cold head and the heat pipe 2 inside it so that they are in contact with each other.

[0042] Preferably, thermally conductive materials such as silicone grease are used to fill tiny gaps on the surface between the heat pipe 2 and the first fixing device 4 and the second fixing device 5 .

[0043] Furthermore, the heat pipe 2 is fixedly connected to the cylinder housing 10 or the cold head base 16 of the cryopump 1, and the heater 3 is fixedly connected to the heat pipe 2. The heat pipe 2 and the cylinder housing 10 or the cold head base 16 are sealed.

[0044] Preferably, the heat pipe 2 is fixed to the cylinder housing 10 or the cold head base 16 of the cryopump 1 by welding.

[0045] Furthermore, the shell of the heat pipe 2 is made of aluminum, copper, aluminum alloy or copper alloy, and a capillary structure is provided inside the shell of the heat pipe 2. The heat pipe 2 is filled with a working fluid. The capillary structure is a conventional technology, such as a sintered structure, a groove, etc., which uses capillary phenomena to move the liquid.

[0046] Preferably, the melting point of the working fluid in the heat pipe 2 is lower than -100°C and the critical temperature is higher than 0°C.

[0047] More preferably, the working fluid in the heat pipe 2 can be ethanol, Freon (such as R23, ‌R508B, etc.), and other low-temperature and ultra-low-temperature refrigerants (such as R600a, etc.).

[0048] During operation, the cryopump 1 cools down internally, allowing the cold shield 12 and cold umbrella 13 to adsorb gas molecules at low temperatures. During operation, due to the excessively low temperature of the cryopump 1, the working fluid within the heat pipe 2 solidifies, halting its phase transition. At this point, the heat pipe 2 exchanges heat with the outside world only through conduction, significantly reducing its thermal efficiency. This minimizes the impact of the external temperature on the cryopump 1, allowing the interior of the cryopump 1 to smoothly cool to the desired temperature.

[0049] During regeneration, heater 3 heats flat plate 21. This heat is then conducted along the metal heat pipe 2 to the contact points between the heat pipe 2 and the primary and secondary cold heads 14, 15, melting the solidified working fluid within the heat pipe 2. Once the working fluid melts, the heat pipe 2 undergoes a smooth phase change and conducts heat, significantly improving thermal conductivity. This allows a large amount of heat to be transferred to the primary and secondary cold heads 14, 15 in a short period of time, rapidly heating them and shortening regeneration time. Subsequently, heater 3 stops operating when a specified temperature is reached, as detected by the temperature sensor within cryopump 1.

[0050] The thermal conductivity of metal increases at low temperatures, which is beneficial for the heat pipe 2 to quickly melt the solidified working fluid.

[0051] The cryopump 1 is a prior art cryopump, such as the cryopump disclosed in Chinese Utility Model Patent No. CN117489563B. The primary and secondary cold heads 14, 15 of the cryopump 1 are located within the cylinder housing 10 and outer housing 11, respectively, which are fixedly connected. The cold shield 2 and cold umbrella 3 of the cryopump body 1 are disposed within the outer housing 11, with the end of the cylinder housing 10 secured to the base via a cold head base 16.

[0052] It should be noted that the heating device of this embodiment can directly replace the electric heating rod in the existing cryopump 1. The heat pipe 2 can extend through a hole punched in the cylinder housing 10, or through an existing hole in the cold head base 16 of the cryopump 1. The point where the heat pipe 2 passes through needs to be sealed.

[0053] Example 2:

[0054] like Figures 1 to 5 As shown, this embodiment is a further improvement on the first embodiment, and further comprises a thermal insulation sleeve 8 , which is sleeved on the portion of the heat pipe 2 extending from the cryopump 1 and the outside of the heater 3 .

[0055] Furthermore, a thermal insulation layer 6 is included, which covers the portion of the heat pipe 2 extending from the cryopump 1 and the surface of the heater 3. The thermal insulation layer 6 is in contact with the cylinder housing 10 or the base of the cryopump, and the thermal insulation sleeve 8 is located outside the thermal insulation layer 6. The thermal insulation layer 6 is used to block air convection inside and outside the thermal insulation layer 6 to reduce heat transfer.

[0056] Optionally, the thermal insulation layer 6 is a silicone sleeve, the silicone adheres to the portion of the heat pipe 2 extending out of the cryopump 1 and the heater 3, and the end of the silicone is bonded and fixed to the cylinder housing 10 or the outer side of the base of the cryopump, so that the inside and outside of the thermal insulation layer 6 are sealed.

[0057] Optionally, the thermal insulation layer 6 is a thermal insulation coating, and thermal insulation is achieved by spraying the coating on parts of the cryopump 1 and the surface of the heater 3 .

[0058] Furthermore, the end of the thermal insulation sleeve 8 is fixed and sealed to the cylinder housing 10 or the base of the cryopump, and the thermal insulation sleeve 8 is elastic.

[0059] Preferably, the heat-insulating sleeve 8 is a heat-insulating cotton with aluminum foil arranged inside, and the aluminum foil is used to reduce heat radiation.

[0060] During operation, the temperature inside the cryopump 1 decreases, and the thermal insulation sleeve 8 reduces the cooling capacity lost by the portion of the heat pipe 2 extending from the cryopump 1. During regeneration, the thermal insulation sleeve 8 reduces the loss of heat generated by the heater 3. By providing thermal insulation, the thermal insulation sleeve 8 reduces energy consumption.

[0061] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments. Any changes or modifications based on the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A cryopump heating device, characterized in that: The invention comprises a heat pipe (2) and a heater (3), wherein the heat pipe (2) passes through a cryogenic pump (1), the heat pipe (2) contacts a first-stage cold head (14) and a second-stage cold head (15) inside the cryogenic pump (1), and the heater (3) is located outside the cryogenic pump (1) and contacts the heat pipe (2).

2. A cryopump heating device according to claim 1, characterized in that: The portion of the heat pipe (2) extending from the cryopump (1) is formed with a flat plate portion (21), and the heater (3) is in contact with the flat plate portion (21). The heater (3) is an electric heater.

3. The cryopump heating device according to claim 1, characterized in that: It also includes a first fixing device (4) and a second fixing device (5), wherein the first fixing device (4) fixes the heat pipe (2) to the first-level cold head (14), and the second fixing device (5) fixes the heat pipe (2) to the second-level cold head (15).

4. The cryopump heating device according to claim 1, characterized in that: The heat pipe (2) passes through the cylinder housing (10) and is fixedly connected to the cylinder housing (10), and the heater (3) is fixedly connected to the heat pipe (2).

5. The cryopump heating device according to claim 1, characterized in that: The shell of the heat pipe (2) is made of aluminum, copper, aluminum alloy or copper alloy; a capillary structure is provided inside the shell of the heat pipe (2); and the heat pipe (2) is filled with a working fluid.

6. The cryopump heating device according to claim 5, characterized in that: The melting point of the working fluid in the heat pipe (2) is lower than -100°C and the critical temperature is higher than 0°C.

7. The cryopump heating device according to claim 6, characterized in that: The working fluid is ethanol, R23, R508B or R600a.

8. The cryopump heating device according to claim 2, characterized in that: It also includes a heat insulation sleeve (8), which is sleeved on the outside of the heat pipe (2) and the heater (3).

9. The cryopump heating device according to claim 8, characterized in that: It also includes a thermal insulation layer (6), which covers the portion of the heat pipe (2) extending out of the cryogenic pump (1) and the surface of the heater (3), and the thermal insulation sleeve (8) is located outside the thermal insulation layer (6).

10. The cryopump heating device according to claim 9, characterized in that: The heat-insulating layer (6) is a silicone sleeve or a heat-insulating coating.

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