Magnet assembly for sputter ion pump

Abstract

A magnet assembly for a sputter ion pump (SIP), comprising a pole piece, at least one magnet coupled to the pole piece by the magnetic force of the at least one magnet, at least one cathode element coupled to the at least one magnet, and at least one bracket element coupled to the at least one magnet by the magnetic force of the at least one magnet, wherein the at least one bracket element fixes the position of the at least one cathode element.

Description

Technical Field

[0001] The present invention relates to a magnet assembly of a sputter ion pump (SIP) and a vacuum pump comprising such a magnet assembly of a sputter ion pump module.

Background Art

[0002] A generally known SIP includes one or more anodes made as tubes or cylindrical openings, and the magnetic field is directed parallel to the central axis of the tube. The anode is surrounded by a cathode element. Specifically, the cathode element is disposed at a certain distance along the central axis opposite to the cylindrical opening of the anode. A strong electric field is generated between the anode and the cathode. The magnetic field expands the path of electrons in the anode cell, and gas atoms and molecules in the vacuum chamber are ionized. The resulting ions are accelerated and collide with the cathode element. When the accelerated ions collide with the cathode element, the ions are embedded in the cathode material or sputter the cathode material onto other surfaces of the pump. The continuously sputtered chemically active cathode material functions as a getter, expelling gas by both chemisorption and physisorption, resulting in a net pumping action.

[0003] In a general vacuum pump, the cathode plate of the SIP is usually held in a predetermined position in the pump using welding or fasteners. This requires additional steps during assembly or additional parts in a vacuum. Specifically, when the cathode is welded, element replacement is impossible.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a magnet assembly of a sputter ion pump with a simplified design arranged in a vacuum.

Means for Solving the Problems

[0005] This problem is solved by the magnet assembly described in claim 1 and the vacuum pump described in claim 12.

[0006] The magnet assembly of the sputter ion pump (SIP) according to the present invention comprises a pole piece and at least one magnet coupled to the pole piece by the magnetic force of at least one magnet. Furthermore, at least one cathode element is coupled to at least one magnet. Here, the cathode element can be directly coupled to and in direct contact with at least one magnet, or can be indirectly coupled to at least one magnet by the presence of an intermediate element between the cathode element and at least one magnet. Furthermore, the magnet assembly according to the present invention comprises at least one bracket element coupled to at least one magnet by the magnetic force of at least one magnet, the at least one bracket element fixing the position of at least one cathode element. Thus, according to the present invention, at least one magnet is fixed in a predetermined position relative to the pole piece by its magnetic force. Preferably, the pole piece is made of a magnetic material and an attractive force exists between at least one magnet and the pole piece. Since at least one magnet is coupled to the pole piece by the already existing magnetic force of at least one magnet, further fasteners or other fastening means can be eliminated. Therefore, at least one magnet has two functions: firstly, to provide a magnetic field to the SIP, and secondly, to fix the position of at least one magnet itself relative to the magnetic pole piece. In addition, at least one cathode element is coupled to at least one magnet by the magnetic force of at least one magnet. Therefore, no further fasteners or fixing means are needed to fix the position of at least one cathode element, and additional parts in the vacuum can be eliminated. Thus, a bracket element is implemented to clamp or hold at least one cathode element in its predetermined position, and the bracket element is coupled to at least one magnet by the magnetic attraction force between the bracket element and at least one magnet. This facilitates the assembly of the SIP and allows the magnet assembly to be placed completely in the vacuum.

[0007] Preferably, at least one bracket element is made of a magnetic material. Thus, an attractive force is generated between the at least one bracket element and at least one magnet that holds the bracket element and, as a result, the cathode element in place.

[0008] Preferably, the magnet assembly comprises one or more magnets.

[0009] Preferably, one or more magnets are neodymium magnets or samarium cobalt magnets.

[0010] Preferably, if the magnet assembly includes two or more magnets, at least two magnets are separated by a separation element placed between each of the two magnets. The separation element can be made of a magnetic material. Preferably, the separation element is formed integrally with the pole piece. Thus, the separation element allows the two magnets to be placed in close proximity and eliminates the magnetic repulsive force between equally magnetically oriented magnets.

[0011] Preferably, the pole pieces and bracket elements are nickel-plated to reduce gas release in a vacuum environment.

[0012] Preferably, the cathode element is made of titanium, tantalum, or a combination thereof. Therefore, since the cathode element is not attracted by the magnetic force of at least one magnet, the cathode element is fixed in the magnet assembly by at least one bracket element.

[0013] Preferably, the cathode element is plate-shaped to provide a large surface area for the pumping action of SIP.

[0014] Preferably, the cathode element is provided as a single integrated component. This further reduces the number of elements in the vacuum and simplifies the assembly of the SIP.

[0015] Preferably, the pole pieces are cylindrical, semi-cylindrical, or partially cylindrical, i.e., having a circular cross-section, a semi-circular cross-section, or a partially circular cross-section, respectively. When the pole pieces of the SIP vacuum pump are semi-cylindrical, two magnet assemblies can be combined to provide a cylindrical SIP module, as detailed below.

[0016] Preferably, the magnetic pole piece has a recess, and at least one magnet is placed in the recess. Here, preferably, the recess has a size equal to the combined size of one or more magnets. If there is one magnet, the recess has dimensions corresponding to the dimensions of the magnet in order to prevent the magnet from moving. If there are two or more magnets, the recess has a size corresponding to the combined total dimensions of the two or more magnets. Thus, the position of the magnet is fixed by the recess. The magnetic force of one or more magnets fixes the magnet within the recess, and the side walls of the recess restrict the movement of the magnet.

[0017] Preferably, at least one bracket element covers at least a portion of the surface of at least one cathode element that faces outward from at least one magnet. In other words, at least one bracket element at least partially surrounds at least one cathode element, including the surface that faces outward from at least one magnet. This allows a clamping force to be generated by clamping at least one cathode element toward the magnet.

[0018] Preferably, the magnet has a first surface that contacts or faces the cathode element and a side surface perpendicular to the first surface. Preferably, at least one magnet has a second surface opposite to the first surface that contacts the pole piece.

[0019] Preferably, the entire first surface of at least one magnet is in direct contact with the cathode element.

[0020] Preferably, the entire second surface of at least one magnet is in direct contact with the pole piece and is coupled to the pole piece by the magnetic attraction of at least one magnet.

[0021] Preferably, at least one bracket element is coupled to one of the sides, and more specifically, the bracket element is coupled to each of the two opposite sides. Thus, the bracket element is positioned on the side of at least one magnet, or the magnet assembly comprises two bracket elements coupled to the two opposite sides of at least one magnet. If two or more magnets are present, two bracket elements can be coupled to the sides opposite the outermost magnet, i.e., the surface opposite the outermost magnet.

[0022] Preferably, at least one bracket element protrudes above the first surface of the magnet in the direction of the cathode element by a length corresponding in detail to the thickness of at least one cathode element. More specifically, if at least one bracket element surrounds at least one cathode element in part, the at least one bracket element protrudes above the first surface of the magnet and reaches the surface of at least one cathode element facing outward from the magnet.

[0023] Preferably, the cathode element has a chamfered edge, the chamfered portion of which faces outward from at least one magnet. Furthermore, the bracket element has a corresponding chamfered portion facing toward the magnet, and the chamfered edge of the cathode element is in direct contact with the chamfered portion of the bracket element to apply a clamping force toward the magnet to at least one cathode element.

[0024] Preferably, the chamfered edge of the cathode element has an angle of 45° or less, more preferably less than 45°, and most preferably 30° or less. By reducing the angle of the chamfered edge, the contact area between the chamfered edge of the cathode element and the chamfered portion of the bracket element is increased, and the holding force, i.e., the force component in the direction of the magnet clamping the cathode element, is increased.

[0025] Preferably, the bracket element is flush with the surface of the cathode element. Specifically, the bracket element is flush with the surface of the cathode element facing outward from the magnet. Thus, the bracket element can be made compact, and the cathode element can be arranged close to the anode of the SIP.

[0026] Preferably, according to the present invention, there is no additional fixing element or fastening means for holding at least one cathode element and / or at least one magnet in their predetermined positions. Specifically, the magnet and the cathode element are held in their predetermined positions only by the magnetic force of at least one magnet via the bracket element.

[0027] In another aspect of the present invention, a vacuum pump is provided that includes a sputter ion pump (SIP) module including an anode and at least one magnet assembly as described above.

[0028] Preferably, the SIP module includes two or more magnet assemblies, and the two or more magnet assemblies are combined into the cylindrical shape of the SIP module.

[0029] Preferably, the vacuum pump further includes a non-evaporable getter (NEG) module, preferably an upper element of the SIP module, i.e., a non-evaporable getter (NEG) module coupled in a stacked manner on the upper part of the SIP module. Specifically, the NEG module may be directly coupled to the upper element of the SIP module. Alternatively, the NEG module may be coupled to the upper element of the SIP module via an intermediate element to facilitate the coupling between the NEG module and the SIP module.

[0030] Preferably, the outer structure of the SIP module and / or the outer structure of the NEG module is cylindrical. Here, in the case of the SIP module, the outer structure can be provided by a shell having a cylindrical shape. The outer structure can be a housing, which may or may not be vacuum-sealed. The housing allows the SIP module and / or NEG module to function fully and preferably provides means for connecting a vacuum pump to a vacuum device or vacuum chamber. Alternatively, the outer structure surrounds the elements of the SIP module and / or NEG module and is constructed to be inserted into a vacuum device or vacuum chamber. Here, the outer structure may have openings that allow gas to enter the SIP module or NEG module.

[0031] Preferably, the outer surfaces of the SIP module and the NEG module, and more specifically their respective outer structures, are flush with each other to provide the overall cylindrical shape of the vacuum pump.

[0032] Preferably, the vacuum pump has a flange, and the SIP module is coupled to the flange at its first end and preferably to the NEG module at its second end. More specifically, the SIP module is directly coupled to the flange by a base element, and the NEG module is coupled to the SIP module via an upper element of the SIP module. Alternatively, the base element of the SIP module is provided by a flange for coupling the SIP module / NEG module to a vacuum device or vacuum chamber.

[0033] Preferably, the SIP module and NEG module are positioned within the flange area. Thus, the SIP module and NEG module can be inserted together into the vacuum chamber and secured to the vacuum chamber by the flange.

[0034] Preferably, the NEG module and / or SIP module are located in a complete vacuum. More specifically, the small construction size of the NEG module and SIP module allows both to be inserted into a vacuum chamber and coupled to the vacuum chamber by flanges. Thus, no additional vacuum space volume is added to the vacuum chamber in which the vacuum pump is installed, and at the same time, the present invention reduces the number of parts in vacuum compared to when a standard ion pump design is modified to be mounted on flanges.

[0035] Preferably, the SIP module has an outer structure, and the outer structure is made of magnetic pole pieces.

[0036] The present invention will be described in further detail below with reference to the attached drawings. [Brief explanation of the drawing]

[0037] [Figure 1] This is a vacuum pump according to the present invention. [Figure 2] Figure 1 is a cross-sectional view of a vacuum pump. [Figure 3] Figure 1 shows the frame structure of the vacuum pump. [Figure 4A] Figure 1 shows the frame structure and anode of the vacuum pump. [Figure 4B] Figure 1 shows the frame structure and anode of the vacuum pump. [Figure 5A] Figure 1 shows the shell elements of the vacuum pump. [Figure 5B] Figure 1 shows the shell elements of the vacuum pump. [Figure 5C] Figure 1 shows the shell elements of the vacuum pump. [Figure 6A] This is a cross-sectional view of a non-evaporative getter module. [Figure 6B] This is a cross-sectional view of a non-evaporative getter module. [Figure 7] This is a connecting element according to the present invention. [Figure 8A] This is a thermal insulation element according to the present invention. [Figure 8B]This is a thermal insulation element according to the present invention. [Figure 9] Figure 1 is a cross-sectional view of the SIP module. [Modes for carrying out the invention]

[0038] Referring to Figure 1, a vacuum pump 10 according to the present invention is shown. Here, the vacuum pump 10 comprises a non-evaporative getter (NEG) module 12, a sputter ion pump (SIP) module 14, and a vacuum flange 16. Here, the SIP module 14 is directly coupled to the flange 16, and the NEG module 12 is attached to the SIP module 14 on the opposite side of the flange 16. The vacuum pump 10, in particular both the NEG module 12 and the SIP module 14, have a cylindrical shape. The shape of the SIP module 14 closely matches the shape of the NEG module 12, so that the SIP module 14 and the NEG module 12 have substantially similar or identical external shapes or, finally, cross-sections. In the following figures, the vacuum pump has a cylindrical shape, but other shapes are also possible.

[0039] The NEG module 12 and SIP module 14 are positioned within the area of ​​the flange 16 and can be fully inserted into the vacuum chamber for pumping.

[0040] Refer to Figure 2. In the cross-sectional view, the SIP module 14 is shown to have an anode 20, and in the example of Figure 2, it has three cylindrical openings or tubes. Any other number of tubes is also possible. Cathodes 18 are located at the axial ends of these openings. The anode 20 is guided through the flange by a vacuum feedthrough 26 and is maintained at a high potential by a high-voltage (HV) conductor 28 connected to the anode. Furthermore, the flange 16 is provided with a connector 68 which is connected to a heating element 32 of the NEG module 12 via a conductor 30. The NEG element 34 is positioned on the heating element 32 to reactivate the NEG material by heating.

[0041] Here and below, the axial direction of the SIP and its elements is defined along the anode from its bottom to its top. Here and below, the transverse direction refers to the direction perpendicular to the axial direction of the anode.

[0042] Refer to Figure 3, which shows the frame structure 48 of the SIP module. The frame structure 48 comprises a base element 50 that can be attached to the flange 16 by welding, brazing, soldering, screws, or some other releaseable coupling means. In other embodiments, the flange 16 and the base element 50 may be made integrally, or the base element 50 may be provided by the flange 16 itself. In the example in Figure 3, two frame side elements 24, made as shouldered screws or struts extending from the base element 50 to the upper element 52, are coupled to the base element 50. The NEG module 12 can be coupled to the upper element 52 by welding, brazing, soldering, screws, or some other releaseable coupling means. During assembly, the anode 20 is fixed within the frame structure 48, and then the frame structure 48 is coupled to the flange 16 together with the anode 20. This is shown in Figures 4A and 4B. The anode 20 is coupled within the frame structure 48 by a lower support element 71 provided by an insulating element 62 coupled to the anode 20. Furthermore, the upper support element 73 is provided by an insulating element 74, where the insulating elements 62 and 74 are made of an insulating material such as ceramic material. The lower insulating support 71 restricts the anode 20 from downward movement toward the flange 16 and can also restrict lateral movement, i.e., movement in one or more other directions or all other directions. The upper support element 73 restricts the anode 20 from upward movement and lateral movement, i.e., movement in one or more other directions or all other directions. At least one support element 71, 73 or two support elements 71, 73 may not completely restrict lateral movement while connecting the anode to the HV conductor 28, allowing slight lateral movement of the anode to facilitate attachment of the HV conductor 28 to the anode 20. Thus, a secure connection between the HV conductor 28 and the anode 20 is possible, and slight manufacturing deviations can be compensated for. To completely prevent the anode 20 from moving and to fix the anode's position within the frame structure, the anode 20 is coupled to an HV conductor 28 extending through an opening in the base element 50 via a conductive sleeve 49 that couples the anode 20 to the HV conductor 28 of the vacuum feedthrough 26.Therefore, the anode 20 is fixed in place within the frame structure 48 of the SIP module 14 by the coupling of the lower support element 71, the upper support element 73, and the electrical feedthrough 26 to the HV conductor 28.

[0043] Therefore, the steps for assembling the SIP module 14 are: a) A step of providing a frame structure preferably comprising a base element 50, one or more frame side elements 24 coupled to the base element, and upper elements 52 coupled to each frame side element 24, b) Inserting the anode and connecting the anode to the frame structure by the lower support element 71 and the upper support element 73, c) The step of attaching the frame structure 48 together with the anode 20 to the flange 16, thereby coupling the anode 20 to the electrical feedthrough 26 and at the same time fixing the position of the anode 20 within the SIP module 14. d) The step of attaching the shell around the frame structure 48, as will be described in detail below. Includes.

[0044] Refer to Figures 5A-5C, which show details of the shell of the vacuum pump 10. The shell of the vacuum pump 10, more specifically the shell of the SIP module 14, comprises two separate shell elements 22. Here, each shell element 22 is made identically in this embodiment, but the shell elements 22 can also be made / designed differently. Each shell element 22 comprises at least one magnet 78, and in the example of Figures 5A-5C, each shell element 22 comprises two magnets 78. Here, the magnets 78 are positioned in recesses 79 of the shell element 22 to prevent lateral movement. The size of the recesses 79 is adapted to the size of the magnets such that the side walls of the recesses 79 are in direct contact with the side walls of each magnet 78. The magnets 78 are attached to each shell element 22 solely by their magnetic force. There are no further fixing / fastening elements. Thus, the shell elements 22 serve as both the magnetic pole pieces and the outer structure of the SIP module 14. The pole pieces guide the magnetic flux through the SIP module 14, and the outer structure provides structural stability to the SIP module 14. Therefore, the shell element 22 is made of a magnetic material such as mild steel. The magnet 78 is a neodymium (Nd) magnet or a samarium (Sa) cobalt (Co) magnet. One surface of the magnet is attached to the shell element 22. The opposite surface of the magnet 78 is directly coupled to the cathode 18. The cathode 18 is plate-like and covers all or substantially all of the surface of the magnet 78. The cathode 18 can be made of titanium (Ti) or tantalum (Ta). Two shell elements 22 may have cathode elements 18, 18' made of the same or different materials. Bracket or clamp elements 80 are provided at the upper and lower ends of each magnet 78 to fix the cathode 18 in place. The bracket elements 80 are held in place by the magnetic force of the magnet 78. No additional fixing elements are required. The bracket element 80 has a chamfered surface 84, which includes a chamfered portion facing the magnet 78. Similarly, the cathode element 18 has a chamfered portion facing outward from the magnet 78, and a chamfered edge 82 that corresponds to the chamfered surface 84 of the bracket element 80. When the bracket element 80 is attached to the side of the magnet 78, a clamping force is applied to the cathode 18 to fix its position.Since the surface of the cathode element 18 is flush with each bracket element 80, the cathode element 18 can be positioned closely with respect to the anode 20. Furthermore, the anode element 18 can be assembled and disassembled without the need for additional tools.

[0045] The two shell elements 22 are similar in shape to the SIP module 14. The shell elements 22 have openings 23 that allow gas molecules and particles to enter the active volume of the SIP module. The present invention is not limited by the number or shape of these openings 23. To ensure sufficient stability of the shell elements, the shell elements 22 are provided with recesses 81 along the axial direction of the shell elements 22 at their axial ends, which accommodate the frame side elements 24 when attached to the shell elements 22. Thus, the position of the shell elements 22 is determined by the position of the frame side elements 24, by the corresponding shape of the recesses 81.

[0046] Refer to Figures 6A and 6B, which show an NEG module 12 comprising a heater 32 having a heating wire 86. The NEG module 12 comprises a base element 88 and an upper element 90, and the NEG element 34 is sleeved over the heater 32. The upper element 90 and the base element 88 can be connected by NEG side elements such as shouldered screws or struts. In detail, the NEG side elements are made of threaded rods or struts. Electrical connection of the heater 32 is provided by an electrical connector 38 having a connecting element 94. The connecting element 94 is shown in detail in Figure 7. The connecting element 94 comprises a first end 96 and a second end 98. Between the first end 96 and the second end 98, there is a collar or protruding feature 100. Although Figure 7 shows that the first end 96 and the second end 98 may have the same diameter, the present invention is not limited to this example, and different diameters of the first end 96 and the second end 98 are also possible. Similarly, while the example in Figure 7 shows a circular cross-section, other shapes are, of course, also possible.

[0047] As shown in Figures 8A and 8B, the connector 38 comprises insulating elements 102 and 106. The first insulating element 102 has an opening 104, where the number of openings 104 corresponds to the number of connecting elements 94. The diameter of the opening 104 corresponds to the diameter of the first end 96, and preferably the insulating element 102 is made of ceramic material. Similarly, the second insulating element 106 is made of ceramic material. The second insulating element 106 is made of two halves, although Figure 8B shows only a single half. The two halves of the insulating element 106 define an opening 108, where the diameter of the opening 108 corresponds to the diameter of the second end 98 of the connecting element 94. The connecting element 94 is crimped to the heating wire 86 of the heater 32 or otherwise attached. The two halves of the second insulating element are then inserted into the housing of the base element 88 of the NEG module 12 and seated on the shoulder portion 95. Here, the protruding feature 100 prevents the connecting element 94 from falling through the opening 108 of the second insulating element 106. The first insulating element 102 is then assembled by inserting the first end 96 of the connecting element 94 into the respective openings 104. The protruding feature 100 prevents the connecting element 94 from falling out of the first insulating element 102. The first insulating element 102 and the second insulating element 106 are fixed in place by a fixing element, for example, provided by a set screw. This prevents clamping force from directly acting on the connecting element 94. The protruding feature 100 fixes the fixing element 94 in its axial position, while slight lateral movement of the connecting element 94 is still permitted, which is useful when assembling the NEG module 12.

[0048] Similar to the connector 38 that connects the NEG module 12 to the SIP module 14, a connector 40 is provided to connect the SIP module to the flange 16, as shown in Figures 4A and 4B. This allows the conductor 30 connected to the heater 32 to pass completely through the flange 16 to the SIP module 14 and then to the NEG module 12 via the connector 38. The conductor 30 may include two electrical wires 110, 110' surrounded by an insulating material such as ceramic.

[0049] The following refers to Figure 9, which shows a cross-sectional top view of the SIP module 14. The anode 20 has a first surface 114 and a second surface 118 on the opposite side, which correspond axially to the cylindrical opening of the anode 20. The first surface 114 and the second surface 118 are joined by a side surface 116, and the conductor 30 extends along the side surface 116 of the anode 20. Due to the position of the conductor 30, there is no direct line or line of sight 112 between the cathode element 18 and the conductor 30, thus preventing or at least reducing the possibility of sputtering the cathode material onto the surface of the conductor 30, which could cause a short circuit. Thus, the conductor 30 is protected by the anode 20 itself. Accordingly, the side surface 116 of the anode can be provided with recesses 120 for accommodating the conductor 30 and the respective wires 110, 110' of the conductor 30. Therefore, the low-voltage supply to the heater 32 of the NEG module 12 is provided from the connector 68 through the connecting element 40 and the conductor 30 across the SIP module 14, more specifically through the magnetic pole piece of the SIP module provided by the shell element 22, toward the connector 38 of the upper element 52 of the SIP module, and further toward the connector 38 and the heater 32.

[0050] Accordingly, the vacuum pump according to the present invention provides a combination of NEG modules and SIP modules, both of which can be fully inserted into a vacuum chamber with a small cross-sectional area. At the same time, the mounting of the frame structure 48 and shell simplifies the assembly process of the SIP module 14 and reduces the number of parts required in vacuum. [Explanation of symbols]

[0051] 10 Vacuum pump 12 NEG modules 14 SIP Modules 16 flange 18, 18' Cathode element 20 Anode 22 Shell Elements 23 Opening 24 Frame side elements 26 Vacuum feedthrough 28 HV conductor 30 conductor 32 heating element 34 NEG elements 38 connectors 40 connectors 48 Frame Structure 49 Conductive sleeve 50 Base elements 52 Top element 62 Insulating elements 68 connectors 71 Lower support element 73 Upper support element 74 Insulating elements 78 Magnets 79 Recess 80 Bracket Elements 81. Indentation 82 Chamfered edge 84 Chamfered surface 86 Heating wire 88 Base element 90 Top element 94 connection elements 95 Shoulder 96 First end 97 Fixed elements 98 Second end 100 Protruding feature 102 First insulating element 104 Opening 106 Second insulating element 108 Opening 110, 110' wire 112 Line of sight 114 First surface 116 Side view 118 Second surface 120 indentations

Claims

1. A magnet assembly for a sputter ion pump (SIP), Magnetic pole pieces and, A magnet comprising at least one magnet, wherein at least one magnet is coupled to the pole piece by the magnetic force of the at least one magnet, At least one cathode element coupled to the at least one magnet, At least one bracket element coupled to the at least one magnet by the magnetic force of the at least one magnet, Equipped with, The at least one bracket element is a magnetic assembly that fixes the position of the at least one cathode element.

2. The magnet assembly according to claim 1, wherein the magnetic pole piece has a cylindrical, semi-cylindrical, or partially cylindrical shape.

3. The magnet assembly according to claim 1, wherein the magnetic pole piece has a recess, and the at least one magnet is disposed in the recess.

4. The recess has a size equal to the combined size of the one or more magnets. The magnet assembly according to claim 3.

5. The magnet assembly according to claim 1, wherein the at least one bracket element at least partially covers the surface of the at least one cathode element that faces outward from the at least one magnet.

6. The magnet assembly according to claim 1, wherein the at least one magnet comprises a first surface that contacts or faces the cathode element and a side surface.

7. The magnet assembly according to claim 6, wherein the at least one bracket element is coupled to one of the sides, and more specifically, the bracket element is coupled to two of the sides opposite to the at least one magnet.

8. The magnet assembly according to claim 6, wherein the at least one bracket element protrudes above the first surface of the magnet by a length corresponding to the thickness of the at least one cathode element.

9. The magnet assembly according to claim 1, wherein the at least one cathode element includes a chamfered edge, the chamfered edge facing outward from the magnet, the bracket element includes a corresponding chamfered edge facing the magnet, and the chamfered edge of the cathode element is in direct contact with the chamfered edge of the bracket element, thereby applying a clamping force to the at least one cathode element.

10. The magnet assembly according to claim 1, wherein the bracket element is flush with the surface of the cathode element.

11. The magnet assembly according to claim 1, wherein there are no further fixing elements for holding the at least one cathode element and / or the at least one magnet in a predetermined position.

12. A vacuum pump comprising a sputter ion pump (SIP) module including an anode and at least one magnet assembly as described in any one of claims 1 to 11.

13. The vacuum pump according to claim 12, wherein the SIP module comprises two or more magnet assemblies, and the cylindrical shape of the SIP module is provided by the two or more magnet assemblies.

14. The vacuum pump according to claim 12, wherein the magnet assembly is placed in a vacuum.

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