Gas trapping element
The gas capture element with additive-manufactured structural elements addresses the issue of insufficient active surface area in NEG-coated hardware by increasing the surface-to-area ratio, thereby enhancing the pumping speed and performance of NEG pumps.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- EDWARDS LTD
- Filing Date
- 2024-03-06
- Publication Date
- 2026-05-11
AI Technical Summary
Existing NEG-coated hardware in vacuum applications has insufficient active surface area, leading to inadequate pumping performance due to smooth and compact surfaces formed by sputtering.
A gas capture element with a surface structure comprising multiple structural elements made via additive manufacturing, such as columnar structures or microvilli, increases the active surface area through precise placement and arrangement, enhancing the surface-to-area and surface-to-volume ratios.
The increased active surface area significantly improves the pumping speed and performance of NEG pumps by leveraging additive manufacturing techniques to create a dense and patterned NEG material coating.
Smart Images
Figure 2026514415000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a gas capture element for capturing gas within a non-evaporable getter (NEG) pump. Further, the present invention relates to a method for manufacturing the gas capture element and an NEG pump.
Background Art
[0002] NEG pumps are generally used as ultra-high vacuum (UHV) pumps, where a layer of sintered disk of NEG material is heated and activated inside the device. Also, NEG-coated hardware is used in some UHV applications to reduce the impact of surface gas release in pipes, but also to operate as an additional pumping mechanism.
[0003] The pumping speed of an NEG pump is known to be directly proportional to its active surface area. To achieve this, most current sintered disks intentionally have a high porosity.
[0004] However, hardware such as pipes or other vacuum components is usually coated with NEG material by sputtering, which provides a smooth and compact surface. Thus, the active surface area of NEG-coated hardware is determined by the surface area of the component itself, which tends to have insufficient pumping activity.
Summary of the Invention
Problems to be Solved by the Invention
[0005] An object of the present invention is to provide a gas capture element with improved pumping activity.
Means for Solving the Problems
[0006] This problem is solved by the gas capture element according to claim 1 and the method according to claim 11.
[0007] The gas capture element according to the present invention for capturing gas in a non-evaporative getter pump has a surface structure. The surface structure comprises multiple structural elements of NEG material produced by additive manufacturing. Additive manufacturing is a well-known technique for producing small but precise structural elements, even from metals, by adding material to predetermined locations in a defined manner. Additive manufacturing has been developed in the past, and this technique makes it possible to realize very small structural elements down to the microscale. Furthermore, various types of metals can be used in additive manufacturing, which, when activated, provide a pumping effect as NEG material. Thus, additive manufacturing provides a versatile and reliable technique for creating the surface structure of a gas capture element. Consequently, the use of additive manufacturing adds structural elements to the surface, thereby increasing the active surface area, which leads to an improvement in the pumping performance, i.e., the pumping speed, of the gas capture element.
[0008] The structural elements are made as columnar structures or microvilli. These structural elements can increase the surface area. Specifically, columnar structures or microvilli are suitable for increasing the surface-to-area ratio of the gas-trapping element. This ratio determines the active surface of the gas-trapping element over a given area. In the prior art, when sputtering is used for coating hardware, the surface-to-area ratio is equal to 1. A ratio greater than 1 indicates an increase in the active surface area over the same area. Alternatively, the increase in the active surface area according to the present invention can also be quantified by the surface-to-volume ratio, where the surface is the active surface that produces the pumping effect and the volume is the volume of the getter material. A larger surface-to-volume ratio indicates an increase in the active surface area over a given amount of getter material. Therefore, both the surface-to-area ratio and the surface-to-volume ratio can be used to determine the increase in the active surface area provided by the present invention.
[0009] Preferably, the surface-to-area ratio is greater than 10, preferably greater than 100, and most preferably greater than 1000. Thus, the present invention achieves a sufficient increase in pumping speed due to the increased surface area of the NEG material.
[0010] Preferably, the structural elements have a height-to-width ratio greater than 10, preferably greater than 20. Thus, a sufficient surface area increase of the NEG material is achieved by narrow, tall structural elements.
[0011] Preferably, the structural elements have a height between 5 μm and 1000 μm, preferably between 50 μm and 500 μm. Therefore, depending on the capabilities of the additive manufacturing technology, structural elements of sufficient height can be provided on the surface structure of the gas trapping element to increase the active surface area of the gas trapping element.
[0012] Preferably, the structural elements have a width between 1 μm and 100 μm, preferably between 10 μm and 100 μm. Thus, the structural elements can be small enough to be placed in close proximity, and a large number of structural elements can be arranged within a given area to increase the active surface area of the gas trapping elements.
[0013] Preferably, the distance between two adjacent structural elements is less than 50 μm, preferably less than 20 μm, and most preferably less than 10 μm. Thus, adjacent structural elements can be placed in close proximity to each other. This allows for an increase in the number of structural elements per unit area and an increase in the active surface area of the gas trapping elements.
[0014] Preferably, the periodicity of the structural elements, which indicates the distance from the center point of one structural element to the center point of an adjacent structural element, is less than 100 μm, preferably less than 50 μm, and most preferably less than 20 μm. By reducing the periodicity of the structural elements in this way, the density of structural elements within a given area can be increased, and the active surface area of the gas trapping elements can be increased.
[0015] Preferably, the surface structure is regularly patterned. Additive manufacturing allows for the selection of the placement of structural elements, thus enabling the realization of a regularly patterned surface structure.
[0016] Preferably, the surface structure is 10 / cm 2 More than 100 / cm 2 A rate exceeding 1000 / cm², most preferably 1000 / cm². 2 It has a structural element density exceeding [a certain value]. Therefore, a sufficient number of structural elements can be arranged within a single region to increase the active surface area of the gas trapping element.
[0017] Preferably, the structural elements are substantially identical or different. As used herein, “substantially” means identical within the precision of the additive manufacturing process.
[0018] Preferably, the structural elements are made from NEG materials such as zirconium (Zr), vanadium (Va), titanium (Ti), tantalum (Ta), hafnium (Hf), iron (Fe), aluminum (Al), or alloys of one or more of these elements.
[0019] Another aspect of the present invention provides a method for manufacturing a gas capture element for capturing gas in a non-evaporative getter pump, the method comprising depositing NEG material onto a surface by additive manufacturing to create a surface structure.
[0020] Preferably, this method is constructed in accordance with the characteristics of the gas trapping element described above.
[0021] In a further embodiment, the present invention provides an NEG pump comprising a gas capture element as described above or manufactured as described above.
[0022] The features described above in relation to one aspect of the present invention are similarly applicable to each of the other aspects of the present invention.
[0023] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.
Brief Description of the Drawings
[0024] [Figure 1] It is a schematic cross-sectional view of a gas capture element. [Figure 2] It is a schematic top view of the gas capture element of FIG. 1.
Embodiments for Carrying Out the Invention
[0025] The gas capture element 10 includes a surface 14. The surface 14 can be the surface of vacuum hardware such as a pipe or other type of vacuum component. On the surface 14, the structural element 12 is generated by additive manufacturing. The structural element 12 is made of some NEG material such as Zr, Ti, Ta, or an alloy of one or more of these elements.
[0026] The structural element is made as a pillar or microvilli. The structural element 12 can have various shapes. In addition, the present invention is not limited to the specific number of structural elements shown in the figure. Usually, the gas capture element 10 of the present invention includes a large number of structural elements generated on the surface 14 by additive manufacturing. Further, in the example of the figure, all the structural elements are shown to be similar or identical. However, the present invention is not limited to this configuration, and different structural elements can have different shapes or dimensions that are all employed in one gas capture element. Furthermore, in the example of the figure, it is shown that the structural elements are regularly patterned over the surface area of the hardware. This can be achieved by using additive manufacturing, which is different from random processes such as sputtering, growth methods, or other conventional deposition methods as the technology for creating the structural elements.
[0027] The structural element 12 may have a height H, a width W, a distance D between adjacent structural elements, and a periodicity Δ. The height H of the structural element may be between 5 μm and 1000 μm, preferably between 50 μm and 500 μm. The width W of the structural element 12 may be between 1 μm and 100 μm, preferably between 10 μm and 100 μm. The distance D between two adjacent structural elements 12 may be less than 50 μm, more preferably less than 20 μm, and most preferably less than 10 μm. The periodicity Δ may be less than 100 μm, preferably less than 50 μm, and most preferably less than 20 μm. In detail, the ratio H / W of the height H to the width W of the structural element is preferably greater than 10, more preferably greater than 20. Thus, the density of the structural element can be achieved depending on the configuration and dimensions of the structural element. In detail, the density of the structural element is 10 / cm³. 2 It should be greater than, preferably 100 / cm 2 It should exceed, more preferably 1000 / cm². 2 This can be exceeded. Therefore, in order to increase the surface-to-area ratio, a large number of structural elements 12 can be arranged in a given area. The surface-to-area ratio is determined by dividing the active surface provided by the structural elements by the area of the surface 14 on which the structural elements 12 are arranged. Preferably, the surface-to-area ratio is greater than 10, preferably greater than 100, and more preferably greater than 1000.
[0028] Therefore, when creating structural elements to increase the active NEG coating surface, a substantial increase in the active surface can be achieved by using additive manufacturing techniques. This can increase the pumping performance of the NEG material, specifically the pumping speed. [Explanation of Symbols]
[0029] 10 Gas trapping elements 12 Structural elements 14 Surface
Claims
1. A gas trapping element for trapping gas in a non-evaporative getter pump, wherein the gas trapping element has a surface structure comprising a plurality of structural elements in the form of columnar or microvilli of NEG material produced by additive manufacturing.
2. The gas trapping element according to claim 1, wherein the surface-to-area ratio of the gas trapping element is greater than 10, preferably greater than 100, and more preferably greater than 1000.
3. The gas trapping element according to claim 1 or 2, wherein the structural element has a height-to-width ratio of more than 10, preferably more than 20.
4. The gas trapping element according to any one of claims 1 to 3, wherein the structural element has a height between 5 μm and 1000 μm, preferably between 50 μm and 500 μm.
5. The gas trapping element according to any one of claims 1 to 4, wherein the structural element has a width between 1 μm and 100 μm, preferably between 10 μm and 100 μm.
6. A gas trapping element according to any one of claims 1 to 5, wherein the distance between two adjacent structural elements is less than 50 μm, preferably less than 20 μm, and most preferably less than 10 μm.
7. The gas trapping element according to any one of claims 1 to 6, wherein the surface structure is regularly patterned.
8. The aforementioned surface structure is 10 / cm 2 A rate exceeding 100 / cm², preferably 100 / cm² 2 A rate exceeding 1000 / cm², most preferably 1000 / cm². 2 A gas trapping element according to any one of claims 1 to 7, having a structural element density exceeding [a certain value].
9. The gas trapping element according to any one of claims 1 to 8, wherein the structural element is substantially the same.
10. The gas trapping element according to any one of claims 1 to 9, wherein the structural element is made of Zr, Ti, Ta, Hf, Fe, Va, Al, or an alloy of one or more of these elements.
11. A method for manufacturing a gas capture element for capturing gas in a non-evaporative getter pump, comprising depositing NEG material onto a surface by additive manufacturing to create a columnar or microvilli surface structure.
12. The method according to claim 11, wherein the surface structure is made according to the gas trapping element described in any one of claims 1 to 10.
13. An NEG pump comprising at least one gas capture element, manufactured according to any one of claims 1 to 10 or in accordance with claim 11 or 12.