Heat shield for NEG pump

Abstract

A heat shield element for a non-evaporable getter (NEG) pump, the heat shield element comprising: a shield element made of a sheet metal, the shield element having a first end and an opposite second end, where the first end and the second end are connected by an upper edge and an opposite lower edge, where the shield element comprises a plurality of openings; and a connecting pin at the first end and / or the second end.

Description

[0001] This invention relates to a heat shielding element for a non-evaporative getter (NEG) pump. Further, this invention relates to a heat shield comprising such a heat shielding element. Further still, this invention relates to an NEG pump comprising such a heat shield and a method for assembling such a heat shield.

[0002] Common NEG pumps are used to achieve ultra-high vacuum (UHV) or extremely high vacuum (XHV) in applications such as quantum computing, spectroscopy, or layer deposition techniques. NEG pumps consist of NEG elements that provide a pumping effect by adsorbing gas molecules drawn from a vacuum volume, thereby reducing the pressure within that volume. However, to activate such NEG elements (and to reactivate them after a certain operating time), the NEG elements need to be heated above a certain temperature. Therefore, the NEG elements are connected to heating elements. To prevent thermal radiation from adversely affecting other parts of the vacuum equipment and to improve the efficiency of the heating process, the NEG elements are surrounded by a thermal shield. The thermal radiation generated by the heating elements is then at least partially reflected by the thermal shield.

[0003] However, in common vacuum pumps, heat shields are typically welded or fastened directly to NEG pump components, which reduces the ability to maintain the NEG pump. Furthermore, the entire NEG pump must be handled during the welding process, increasing the complexity of the welding procedure.

[0004] The object of the present invention is to provide a heat shield and an NEG pump including such a heat shield, which can be easily assembled and removed for maintenance without additional fasteners.

[0005] This problem is solved by the heat shielding element according to claim 1, the heat shielding component according to claim 6, the NEG pump according to claim 9, and the method for assembling the heat shielding component according to claim 13.

[0006] In one aspect of the invention, a heat shielding element for a non-evaporative getter (NEG) pump is provided. The heat shielding element comprises a shielding element made of sheet metal having a first end and an opposing second end, wherein the first end and the second end are connected by an upper edge and an opposing lower edge. Further, the shielding element includes a plurality of openings to allow gas molecules to pass through the shielding element and reach the NEG element of the NEG pump. According to the invention, the shielding element includes connecting pins located at the first end, wherein these connecting pins extend beyond the lower and upper edges. Alternatively or additionally, connecting pins are also provided at the second end, extending beyond the lower and upper edges. In particular, the connecting pins extend perpendicular to the lower and upper edges. Thus, the connection between the heat shielding element and the NEG pump can be facilitated by inserting the connecting pin into a corresponding recess in the NEG pump by moving it along the axial axis or the extended axial direction of the connecting pin. Alternatively, the connecting pin may not extend beyond the lower and / or upper edges and can be inserted via lateral movement substantially perpendicular to the axial axis of the pin, preferably by a snap-fit ​​engagement as described below. The heat shield element is connected to the NEG pump via the connecting pin. This connection is releasable and requires no welding. In particular, the connection of the heat shield element to the NEG pump can be facilitated without additional tools. Thus, securing the heat shield element to the NEG pump via the connecting pin simplifies the assembly process without additional fasteners, and the heat shield element can be removed for maintenance. Additionally, the heat shield can be removed before packaging / shipping the NEG box. This allows the getter material to be supported directly by a vacuum-sealed bag or any other packaging material during transport, thereby reducing the shaking / vibration / friction of the NEG material during shipping.

[0007] Preferably, the opening of the shielding element is arc-shaped or elliptical, slotted, or constructed as an elongated hole, or has any other shape.

[0008] Preferably, the area of ​​the opening is between 20% and 80% of the total area of ​​the shielding element, and more preferably between 40% and 60%. This means that 80% to 20%, and more preferably 60% to 40%, of the shielding element is structured as a closed surface, wherein, therefore, 20% to 80%, and more preferably 40% to 60%, of the area of ​​the shielding element is occupied by the opening. Thus, a good trade-off is provided between the shielding effect of the thermal shielding element against thermal radiation, wherein, simultaneously, the conductivity of gas molecules from the vacuum volume toward the NEG element of the NEG pump is sufficiently high.

[0009] Preferably, the shielding element is arc-shaped or curved, and particularly includes a semi-circular shape. Thus, as described in more detail below, a combination of two or more thermal shielding elements can form a complete thermal shield, thereby providing a closed cylindrical shell or enclosure that preferably completely surrounds the NEG element.

[0010] Preferably, the heat shielding element includes more than one, two, three, four, or more than four pins. In particular, the heat shielding element includes exactly four pins, preferably two pins at the first end (one pin at the lower edge and one pin at the upper edge) and two pins at the second end (one pin at the lower edge and one pin at the upper edge).

[0011] Preferably, the connecting pin is connected to the shielding element by welding. The welding of the connecting pin to the shielding element can be done separately from the NEG pump components, so that the adverse effects of welding do not affect the NEG pump.

[0012] Preferably, the pin at the first end is constructed by combining a first post extending from the lower edge to the upper edge. Thus, the pin at the first end is integrally constructed by a first post that extends beyond the upper and lower edges of the shielding element. Alternatively or additionally, the pin at the second end is constructed by combining a second post extending from the lower edge to the upper edge. Thus, the pin at the second end is integrally constructed by a second post that extends beyond the upper and lower edges of the shielding element. The one or more posts have a length that exceeds the length of the first and second ends by the corresponding amount of the pin. In particular, the posts can be welded to the first and / or second ends of the shielding element in conjunction with the welding of the connecting pin, thereby providing a pin at both the upper and lower edges simultaneously. Therefore, the pin at the first end is easily manufactured and reliably attached to the sheet metal of the shielding element. Similarly, the pin at the second end is easily manufactured and reliably attached to the sheet metal of the shielding element. Furthermore, sufficient contact surface is provided between the post and the shielding element to securely attach the post to the shielding element.

[0013] Preferably, the shielding element is wound around a portion of the connecting pin and, more preferably, around a post at the first and / or second end, so as to connect the corresponding pin to the shielding element.

[0014] Preferably, the pins at the upper and lower edges of the first and / or second ends are constructed in combination with the shielding element by rolling the first and / or second ends into a cylindrical shape to form the corresponding pins. The pins are integrally constructed with the shielding element, or in other words, the pins are constructed from the shielding element itself. Therefore, the rolled ends of the shielding element have a small diameter to form the corresponding pins. The bottom and top edges of the rolled first and second ends may or may not extend beyond the upper and lower edges of the shielding element.

[0015] Preferably, the pin extends beyond the lower edge and / or upper edge by 0.2 to 5 mm, more preferably 0.8 to 2.5 mm, and more preferably 1 to 2 mm.

[0016] Preferably, the diameter of one or more of the pins is between 0.5 mm and 4 mm, more preferably between 1 mm and 3 mm, and even more preferably between 1.2 mm and 2 mm.

[0017] All pins can extend beyond the lower and / or upper edges by the same amount. Alternatively, the pins at the lower edge (at both the first and second ends) can extend by a different amount than one of the pins at the upper edge. Alternatively or additionally, the pins at the first end can extend beyond the lower and / or upper edges by a different amount than the pins at the second end. Thus, pins of specific lengths and diameters provide a compact and sufficiently robust fixation of the heat-shielding element to the NEG pump.

[0018] In one aspect of the invention, a heat shield for a NEG pump is provided. The heat shield includes a first heat shield element as described above. Specifically, the heat shield may at least partially and preferably completely surround the NEG element of the NEG pump.

[0019] Preferably, the heat shield includes one or more second heat shield elements, which are also constructed as described above. In particular, the heat shield may combine the first heat shield element and the one or more second heat shield elements to at least partially and preferably completely surround the NEG element of the NEG pump.

[0020] Preferably, at least one of the second heat-shielding elements is different from the first heat-shielding element. Therefore, by selecting different heat-shielding elements, the heat shield can be customized and adjusted according to the corresponding application. Alternatively, the first heat-shielding element and all the second heat-shielding elements are identical.

[0021] Preferably, the first heat shielding element and one or more second heat shielding elements are curved or arc-shaped to form a cylindrical shell or outer casing together to enclose, and preferably completely enclose, the NEG element of the NEG pump. Thus, the heat shielding provides an outer surface that reflects thermal radiation and simultaneously protects the fragile NEG element from mechanical damage during NEG pump operation.

[0022] Preferably, the heat shield has a closed outer surface, but may be open at the upper and lower edges. The heat shield may have a circular outer surface, particularly if the individual heat shield elements are arc-shaped or semi-circular. Alternatively, the cylindrical shell may have a square outer surface or any other shape to receive the NEG elements of the NEG pump.

[0023] In one aspect of the invention, a NEG pump is provided, comprising a base element and a heating element extending from the base element. Heat can be generated by the heating element. Specifically, the heating element is a resistance heating element, so that the heat is generated to activate or reactivate a plurality of NEG elements arranged around the heating element. Further, the NEG pump includes a top element arranged on the side of the NEG elements opposite to the base element. Thus, the NEG elements are held in place between the base element and the top element. Specifically, the top element is connected to the base element by posts or set screws, which connect the base element to the top element and provide mechanical stability to the NEG pump. Further, according to the invention, the NEG pump includes a heat shield as described above, extending between the base element and the top element.

[0024] Preferably, the base element can be connected to or integrally constructed with the flange, allowing the NEG pump to be fully inserted into the vacuum equipment or vacuum chamber.

[0025] Preferably, the shape of the base element and / or the top element corresponds to the shape of the heat shield. In particular, the heat shield is flush with the base element and / or the top element. For example, if the base element and the top element have a circular shape, the heat shield consisting of two or more heat shield elements approximates or is equal to the shape of the base element and the top element.

[0026] Preferably, the heat shield is directly connected to the base element and / or the top element.

[0027] Preferably, one, more than one, and more preferably all pins at the upper edge of the heat shield extend into the corresponding recess of the top element. Thus, the heat shield is directly connected to the top element of the NEG pump with its upper edge.

[0028] Preferably, one, more than one, and more preferably all pins at the lower edge of the heat shield extend into the corresponding recess of the base element. Thus, the lower edge of the heat shield is directly connected to the base element of the NEG pump.

[0029] Preferably, one or more of the recesses are open in a direction perpendicular to the extension of the pin and include undercut portions, allowing the pin to snap into the respective recess. Specifically, the pin can be inserted into the respective recess by lateral movement, i.e., movement perpendicular to the extension of the pin. Thus, the assembly of the heat shield can be tool-free and reversible via snap-fit ​​connections between the pin and the respective top or base element. Specifically, the recess at the top element provides a snap-fit ​​connection, allowing the pin at the lower edge of the heat shield to be inserted (e.g., moved axially along the length of the pin) into the recess of the base element, and subsequently the pin at the upper edge can be snapped into the recess of the top element. Alternatively, the recess at the base element provides a snap-fit ​​connection, allowing the pin at the upper edge of the heat shield to be inserted (e.g., moved along the length or extension of the pin) into the recess of the top element, and subsequently the pin at the lower edge can be snapped into the recess of the base element. Alternatively, both the recesses at the top and base elements provide lateral openings, allowing the pins at the upper and lower edges to be snapped into the corresponding recesses.

[0030] Preferably, adjacent recesses at the base element and / or top element are combined to provide a common recess for the pins of adjacent heat shield elements.

[0031] In one aspect of the invention, a method for assembling a heat shield to an NEG pump is provided. Specifically, the NEG pump is as described above. The method includes: Provide base components; Connect the heating element to the base element and arrange multiple NEG elements around the heating element; Assemble the top element, which is disposed on the side of the plurality of NEG elements opposite to the base element; Assemble the heat shield as described above.

[0032] Preferably, the method includes: inserting a pin of one of the heat shielding elements into a corresponding recess in the base element or the top element, and subsequently inserting a pin of the heat shielding element into a corresponding recess in the other of the base element or the top element.

[0033] Preferably, the insertion of the pin of the heat shielding element into the corresponding recess is performed by a snap-fit ​​engagement.

[0034] Preferably, the method is further defined by the features described above regarding the heat shielding element, the heat shield, and the NEG pump.

[0035] The invention is described in more detail below with reference to the accompanying drawings.

[0036] The attached diagram shows: Figure 1 According to the heat shielding element of the present invention, Figure 2 A cross-sectional view of the NEG pump according to the present invention, and Figure 3 A perspective view of the NEG pump according to the present invention.

[0037] The thermal shielding element 10 for a non-evaporative getter (NEG) pump according to the present invention includes a shielding element 12. The shielding element 12 is made of sheet metal and includes a plurality of openings 20. Figure 1 In the example, opening 20 is shaped as an elongated hole. Other shapes of opening 20 can also be implemented and used for the heat shielding element 12. Specifically, the size of the opening 20 and the spacing between openings 20 provide a trade-off between conductivity allowing gas molecules to enter the volume of the NEG pump and adequate shielding against radiative heat generated during activation or reactivation of the NEG pump. Specifically, the area of ​​opening 20 comprises 20% to 80% of the area of ​​the shielding element 12, and preferably is between 40% and 60% of the area of ​​the shielding element 12.

[0038] The shielding element 12 includes a first end 12a and an opposing second end 12b. The first end 12a and the second end 12b are connected by an upper edge 12c and a lower edge 12d. At the first end 12a and the second end 12b, a post 14 is preferably attached by spot welding. The post 14 extends beyond the upper edge 12c and the lower edge 12d. By extending the post 14 beyond the upper edge 12c, a pin 16 is provided at the upper edge 12c to extend substantially perpendicular to the upper edge 12c. Similarly, a pin 18 is provided at the lower edge 12d by extending the post 14 to extend substantially perpendicular to the lower edge 12d. The heat shielding element 10 can be connected to the NEG pump 11 via pins 16 and 18.

[0039] like Figure 1 As illustrated, the shielding element 12 is arc-shaped and has a semi-circular shape. Therefore, by... Figure 1 The heat shielding element 10 and another heat shielding element 10' (see Figure 3 (This other heat shield element is constructed to be similar to or the same as heat shield element 10, and may also include a semi-circular shape) Combined, heat shield elements 10, 10' provide a cylindrical shell or housing that at least partially and preferably completely surrounds the NEG element 26 of the NEG pump 11 (see Figure 2 ).

[0040] refer to Figure 2The illustration shows a NEG pump 11 according to the invention. The NEG pump 11 includes a base element 30 and a heating element 21 extending from the base element 30. The heating element 21 includes a heating wire 22 along its axial length, wherein the heating wire 22 is connected to an electrical connector 24 at the base element 30. An NEG element 26 is positioned around the heating element 21 such that heat generated by the heating element 21 is applied to the NEG element 26 to activate or reactivate it. The NEG element 26 may be disc-shaped and have an arcuate or circular shape. A top element 28 is provided on the side of the NEG element 26 opposite to the base element 30. The top element 28 can be connected via a post 36 (see...). Figure 3 A set screw or other fastener is attached to the base element to provide mechanical stability to the NEG pump 11. Recesses 34 are provided in the base element 30 to receive pins 18 at the lower edge 12d of the heat shield element 10. Similarly, recesses 32 are provided in the top element 28 to receive pins 16 at the upper edge 12c of the heat shield element 10.

[0041] refer to Figure 3 Using the first heat shield element 10 and the second heat shield element 10' (in Figure 3 In the example, the second heat shield element is constructed identically to the first heat shield element 10 to completely surround the NEG element 26. Gas molecules can enter the active volume of the NEG pump 11 through the opening 20. Due to the semi-circular shape of the first heat shield element 10 and the semi-circular shape of the second heat shield element 10', the heat shield provides a cylindrical shell or outer casing that reflects the thermal radiation generated by the heating element 21 during the activation or reactivation of the NEG element 26.

[0042] like Figure 3 As seen, the recess 34 in the base element 30 is laterally open, i.e., open in a direction perpendicular to the extension of the pin. Further, the recess 34 provides an undercut, allowing the pin 18 at the lower edge 12d of the heat shield 10 to snap into the corresponding recess 34 in the base element 30. Alternatively, the situation can be reversed, where the recess 34 in the top element 28 is laterally open to provide a snap-fit ​​engagement. In an alternative embodiment, neither the recesses in the top element 28 nor the base element 30 are laterally open to provide a snap-fit ​​engagement. Instead, the recesses in the base element 30 and the top element 28 are laterally open and provide a snap-fit ​​engagement for the pins 16, 18 of the heat shield.

[0043] A method for assembling a heat shield may include the following steps: Provide base components; Connect the heating element to the base element and arrange multiple NEG elements around the heating element; Assemble the top element, which is disposed on the side of the plurality of NEG elements opposite to the base element; Assemble the heat shield components.

[0044] Among them, Figure 3 In the example, firstly, the pin 16 at the upper edge 12c of the heat shield element 10 is inserted into the corresponding recess 32 of the top element 28. Then, the pin 18 at the lower edge 12d of the heat shield element 10 is snapped into the recess 34. Subsequently, the second heat shield element 10' is assembled in the same manner.

[0045] List of reference numerals 10. Heat shielding elements 11 NEG pumps 12 Shielding components 12a First end 12b Second End 12c top edge 12d lower edge 14 columns 16 sales 18 sales 20 Opening 21 Heating element 22 Heating wire 24 connectors 26 Heating elements 28 Top Components 30 Base components 32 recess 34 recess 36 columns

Claims

1. A heat shielding element for a non-evaporative getter (NEG) pump, the heat shielding element comprising: A shielding element made of sheet metal, the shielding element having a first end and an opposing second end, wherein the first end and the second end are connected by an upper edge and an opposing lower edge, wherein the shielding element includes a plurality of openings; and A connecting pin located at the first end and / or the second end.

2. The heat shielding element according to claim 1, wherein, The shielding element is arc-shaped or curved, and preferably semi-circular.

3. The heat shielding element according to claim 1 or 2, wherein, The connecting pin is connected to the shielding element by welding.

4. The heat shielding element according to any one of claims 1 to 3, wherein, The pins at the first end and / or the second end are respectively constructed by a combination of posts extending from the lower edge to the upper edge.

5. The heat shielding element according to any one of claims 1 to 4, wherein, The pins at the first end and / or the second end are provided in combination by rolling the respective ends into a cylindrical shape to form the pins.

6. A heat shield for a non-evaporative getter (NEG) pump, comprising a first heat shield element according to any one of claims 1 to 5 and preferably one or more second heat shield elements according to any one of claims 1 to 5.

7. The heat shield according to claim 6, wherein, The first heat shielding element and the one or more second heat shielding elements are curved or arc-shaped to form a cylindrical shell together.

8. The heat shield according to claim 6 or 7, wherein, At least one of the second heat shielding elements is different from the first heat shielding element, or the first heat shielding element and the one or more second heat shielding elements are the same.

9. A NEG pump comprising: Base components; Heating element extending from the base element; Multiple NEG elements arranged around the heating element; A top element, which is arranged on the side of the NEG element opposite to the base element; as well as The heat shield according to any one of claims 6 to 8 extends between the base element and the top element.

10. The NEG pump according to claim 9, wherein, One or more pins at the upper edge of the heat shield extend into the corresponding recess of the top element.

11. The NEG pump according to claim 9 or 10, wherein, One or more pins at the lower edge of the heat shield extend into the corresponding recess of the base element.

12. The NEG pump according to claim 10 or 11, wherein, One or more of the recesses are open in a direction perpendicular to the extension of the pin and include an undercut, allowing the pin to be snapped into the corresponding recess.

13. A method for assembling a heat shield according to any one of claims 6 to 8 into an NEG pump, the method comprising: Provide base components; The heating element is connected to the base element and a plurality of NEG elements are arranged around the heating element; Assemble the top element, which is disposed on the side of the plurality of NEG elements opposite to the base element; Assemble the heat shield according to any one of claims 6 to 8.

14. The method of claim 13, further comprising: Insert a pin of one of the heat shielding elements into the corresponding recess at the base element or the top element; as well as The pin of the same heat shield element is then inserted into the corresponding recess in another of the base element or the top element.

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