Sputter ion pump module and vacuum pump

Abstract

Sputter ion pump, SIP, module comprising a frame structure, an anode connected to the frame structure, and a shell connected to the frame structure, wherein the shell surrounds at least partially the frame structure and the anode, wherein the shell comprises at least one magnet and at least one cathode element.

Description

[0001] The present invention relates to a sputter ion pump (SIP) module and a vacuum pump comprising such SIP module. Further the present invention relates to a method for assembly of such an SIP module. Commonly known SIPs comprise one or more anodes built as tubes or cylindric openings wherein a magnetic field is oriented parallel to the central axis of the tubes. The anode is surrounded by cathode elements. In particular a cathode element is arranged opposite to the cylindric openings of the anode at a certain distance along the central axis. A strong electrical field is generated between the anode and the cathode. Due to the magnetic field, the path of the electrons within the anode cells are augmented which results in ionization of gas atoms and molecules in the vacuum chamber. The resulting ions are accelerated to strike the cathode element. On impact of the accelerated ions on the cathode elements, they will either become buried within the cathode material or sputter cathode material onto the other surfaces of the pump. The continuously sput- tered chemical active cathode material acts as a getter which then evacuates the gas by both chemisorption and physisorption resulting in a net pumping action. In a typical SIP, the pumping element, i.e. comprising cathode elements and anode, is constructed within a vacuum chamber that can be fixed to a vacuum apparatus, and the magnetic field is provided by magnets and a pole piece which are disposed outside the vacuum chamber of the SIP. This design cannot be transferred to a flange-mounted device and would require additional building space within the vacuum chamber and unnecessarily large flanges to incorpo- rate all the functional components of the SIP within the face of the flange. In addition, assembly of the SIP of the prior art requires multiple steps and is complex since it requires assembly of multiple parts within the vacuum cham- ber. It is an object of the present invention to provide a sputter ion pump (SIP) module which can be assembled more easily and provides a modular design for service and repair. The problem is solved by an SIP module according to claim 1, a vacuum pump according to claim 14 and a method for assembly of an SIP module according to claim 19. A sputter ion pump (SIP) module according to the present invention comprises a frame structure, an anode connected to the frame structure and a shell con- nected to the frame structure, wherein the shell surrounds at least partially the frame structure and the anode. Therein the shell comprises at least one magnet and may also comprise at least one cathode element preferably directly con- nected to the shell. However, the at least one cathode element may not be part of the shell or may be not directly connected to the shell. Hence, the shell sim- ultaneously provides the functional components of the SIP module, i. e. the at least one magnet and preferably the at least one cathode element. At the same time the shell provides structural stability of the SIP module. Hence, together, the frame structure and shell provide the complete structure of the SIP requiring no additional structural components. Thus, the overall design is simplified, and the number of necessary parts is reduced. At the same time, the number of steps for assembly can be reduced. Furthermore, since the shell is carrying the at least one magnet, the magnet is disposed in the vacuum chamber together with the complete SIP module. Thus, there are substantially no parts or at least functional components of the SIP module (except for example an electrical feed- through) arranged outside, thereby efficiently using the available space in the vacuum chamber. Preferably, the frame structure comprises a base element and at least one or more frame side elements connected to the base element. Therein the base element provides the basis of the SIP module, wherein the other parts of the SIP module are assembled to the base element and / or to the at least one or more frame side elements of the frame structure. The frame side elements may be built as shoulder screws or posts connected to the base element. Therein, the frame structure may not provide the whole structure stability of the SIP module assembled for operation. Instead, the shell connected to the frame structure may also contribute to the structural stability of the SIP module and only in combination, the frame structure and the shell provide a structural stable SIP module ready for operation. Preferably, the base element may be a flange to connect the SIP module to a vacuum apparatus or vacuum chamber. Alternatively, the base element may be connected to a flange being part of the SIP module or a vacuum pump compris- ing such an SIP module. Preferably, the frame structure comprises a top element wherein the at least one or more frame side element extend from the base element to the top ele- ment. Preferably, the frame structure comprises exactly two frame side elements, i.e. shoulder screws. Preferably, the frame structure consists only of a base element, at least one or more frame side elements and the top element. Thereby the fundamental parts of the SIP module are provided, providing sufficient structural stability for as- sembling the other parts of the SIP module, i. e. the anode and the shell. Preferably, the top element comprises openings to receive the at least one or more frame side elements and further comprises fixing elements to fix the po- sition of the top element on the frame side elements. Thus, the top element may be slidably connected to the at least one or more frame side elements, wherein the position of the top element relative to the at least one or more frame side elements or to the base element can be fixed by the fixing element. In particular the fixing element is provided by a set screw which might be ar- ranged perpendicular to the respective shoulder screws. Preferably, the shell is in direct contact with the base element and preferably in direct contact with also the top element. In particular by the fixing elements direct contact of the top element and the shell can be enabled by adapting the position of the top element on the at least one or more frame side elements. By the fixing element, the position of the top element can be adapted to the shell after assembly of the anode and the shell such that the top element directly abuts the shell. Thereby structural stability is provided and movement / forces on one of the components of the SIP module are transferred via the direct con- tact also to the shell, base element and top element. Preferably, a non-evaporable getter (NEG) pump module is connectable to the top element. Due to the increased structural stability of the SIP module, it is possible to directly attach an NEG pump module on top of the SIP module in a stacking manner. Preferably, the shell is built from a magnetic material and serves as a pole piece. In other terms the pole pieces of the SIP are integrally build with the shell of the SIP module. Thus, the shell not only provides structural stability. At the same time the shell acts as pole piece and has a direct influence on the magnetic field in the SIP module. Preferably, the shell comprises one or more openings to allow gas to inter into the pumping volume of the SIP. Preferably, the shell comprises two or more shell elements. Thereby, assembly of the shell is facilitated due to dividing the shell into two or more shell elements. Preferably, the shell is cylindric and the shell elements are half-cylindric or part- cylindric. In other terms, the shell may have a circular cross section and the shell elements may have a half-circular cross section or part-circular cross sec- tion. Therein the shell elements combine together to the shape of the overall shell. Thus, if there are two shell elements, each shell element may have a half- cylindric shape. However, other shapes of the shell are also possible like a quad- ratic cross section or others. Preferably, each shell element is built identically or differently. By building each shell element identically, assembly is simplified and during manufacturing, a reduced number of parts need to be fabricated. Preferably, each shell element comprises at least on magnet and at least one cathode element. Thereby the at least one magnet and the at least one cathode element is directly connected to the respective shell element and by assembly of the shell element at the same time also the at least one magnet and the at least one cathode element are assembled to the SIP module. Thereby the num- ber of parts to be assembled is reduced and pre-assembly of the respective shell elements is possible. Preferably, each shell element is built from a magnetic material and serves as a pole piece. In other terms the pole pieces are integrally build with the shell of the SIP module. Thus, the shell not only provides structural stability. At the same time the shell acts as pole piece and has a direct influence on the magnetic field in the SIP module. Preferably, the shell elements are connected to each other by a magnetic force of the magnets. In particular no additional fixing elements are present to attach the shell elements to the frame structure. The shell elements are only held in place by the attracting magnetic force of the magnets. Hence, the magnets at- tached to the respective shell elements have two purposes: first, providing the magnetic field for the SIP, second, for assembly of the shell elements and hold- ing the shell elements in place. Thereby assembly of the SIP module is simplified and the number of parts in the vacuum are reduced. In particular tool-free as- sembly of the shell is possible. Preferably, the number of frame side elements corresponds to the number of shell elements. In particular each shell element extends between two frame side elements. If there are two frame side elements of the frame structure, each shell element spans over a half-circle for a cylindric shell. Thereby each shell element is directly connected to the frame structure via a respective pair of frame side element of the frame structure. Preferably, at least one shell element comprises an indentation along an axial edge of the shell element to accommodate one of the frame side elements, i.e. the shoulder screws. Thus, by the indentation, the shell element accommodates the shape of the respective frame side element thereby defining a position of the shell element and aids a placement of the respective shell elements. In particular each shell element comprises such indentation and in particular each shell element comprises on both edges indentations running along in an axial direction. In another aspect of the present invention a vacuum pump is provided compris- ing a sputter ion pump (SIP) module as described before and a non-evaporable (NEG) module connected to the SIP module and preferably connected to the top element of the SIP module. In particular the NEG module might be directly con- nected to the top element of the SIP module. Alternatively, the NEG module might be connected to the top element of the SIP module via an intermediate element in order to facilitate connection between the NEG module and the SIP module. Preferably, an outer structure of the SIP module and / or an outer structure of the NEG module are cylindrical. Therein for the SIP module the outer structure might be provided by the shell having a cylindrical shape. The outer structure may be a housing which may or may not vacuum tight. The housing may render the SIP module and / or the NEG module fully functional and preferably provides means for connecting the vacuum pump to a vacuum apparatus or chamber. Alternatively, the outer structure is surrounding the elements of the SIP module and / or the NEG module and built to be inserted in a vacuum apparatus or cham- ber. Therein, the outer structure may comprise openings to allow gas to enter into the SIP module or NEG module. Preferably, the outer surface of the SIP module and the outer surface of the NEG module, in particular of the respective outer structures, flushes with each other providing an overall cylindrical shape of the vacuum pump. Preferably, the vacuum pump comprises a flange wherein the SIP module is connected with its first end to the flange and preferably with its second end to the NEG module. In particular the SIP module is directly connected by its base element to the flange and the NEG module is connected to the SIP module via the top element of the SIP module. Alternatively, the base element may be a flange to connect the SIP module / NEG module to a vacuum apparatus or vac- uum chamber. Preferably, the SIP module and the NEG module are arranged within an area of the flange. Thus, the SIP module and the NEG module can be together inserted into a vacuum chamber and fixed to the vacuum chamber by the flange. Preferably, the NEG module and / or the SIP module are completely arranged within the vacuum. In particular, due to the small building size of the NEG mod- ule and the SIP module, both can be inserted into a vacuum chamber and con- nected to the vacuum chamber by a flange. Thus, no additional volume of vacuum space is added to the vacuum chamber the vacuum pump is installed on. At the same time due to the present invention the number of parts in the vacuum is reduced relative to if a standard ion pump design were modified in order to be mounted to a flange. In another aspect of the present invention a method for assembly of an SIP module is provided. The method includes: Providing a frame structure; Providing an anode and fixing the anode within the frame structure; Providing two or more shell elements of a shell and attaching the shell elements to the frame structure by a magnetic force. Thus, the anode is connected to the frame structure and subsequently two or more shell elements of a shell are attached to the frame structure. In particular, the shell elements are attached to the frame structure by an attracting magnetic force of the magnets of the SIP module. In particular, no further steps of fas- tening the shell elements to the frame structure are carried out. In particular the shell elements are only attached to the frame structure by the magnetic force. Preferably, the frame structure comprises at least a base element and at least one frame side element connected to the base element to create the frame structure Preferably, after attaching the individual shell elements of the shell to the frame structure, a top element of the frame structure may be aligned in its position to be in direct contact with the upper end of the shell. Thus, the lower end of the shell is in direct contact with base element, wherein the upper end of the shell is in direct contact with the top element. Thereby mechanical loads along the SIP module are directly transferred from the base element via the shell to the top element and distributed across the full perimeter of the pump rather than focused at connection points of the frame side elements to the base and top elements, despite the fact that the shell elements are only connected to the frame structure by their magnetic force. The combination of frame structure and shell provides sufficient stability of the SIP module. Preferably, the SIP module is further built along the features described above. In the following the present invention is described in more detail with reference to the accompanying figures. The figures show: Fig. 1 a vacuum pump according to the present invention, Fig. 2 a sectional view of the vacuum pump of Fig. 1, Fig. 3 a frame structure of the vacuum pump of Fig. 1, Figs. 4A and 4B the frame structure and an anode of the vacuum pump of Fig. 1, Figs. 5A-5C a shell element of the vacuum pump of Fig. 1, Figs. 6A and 6B a sectional view of a non-evaporable getter module, Fig. 7 a connecting element according to the present invention, Figs. 8A and 8B insulation elements according to the present invention, Fig. 9 a sectional view of the SIP module according to Fig. 1. Referring to Figure 1 showing a vacuum pump 10 according to the present in- vention. Therein the vacuum pump 10 comprises a non-evaporable getter (NEG) module 12, a sputter ion pump (SIP) module 14 and a vacuum flange 16. Therein the SIP module 14 is directly connected to the flange 16, wherein the NEG module 12 is attached to the SIP module 14 opposite to the flange 16. The vacuum pump 10 and in particular both the NEG module 12 and the SIP module 14 have a cylindric shape. The shape of the SIP module 14 flushes with the shape of the NEG module 12 such that the SIP module 14 and the NEG module 12 may have a substantially similar or identical outer shape or at last cross- section. Although in the following figures the vacuum pump has a cylindrical shape, other shapes are also possible. The NEG module 12 and the SIP module 14 are arranged within the area of the flange 16 and can be completely inserted into a vacuum chamber for pumping. Referring to Figure 2. In the section view it is shown that the SIP module 14 comprises an anode 20 which has in the example of Figure 2 three cylindrically shaped openings or tubes. Other numbers of tubes are also possible. At an axial end of these openings a cathode 18 is disposed. The anode 20 is kept on a high electrical potential by a high voltage (HV) conductor 28 guided through the flange by a vacuum feedthrough 26 and connected to the anode. Furthermore, the flange 16 comprises a connector 68 which is connected via an electrical lead 30 with a heating element 32 of the NEG module 12. NEG elements 34 are arranged onto the heating element 32 for re-activation of the NEG material by heating up. Here and in the following the axial direction of the SIP and its element is defined along the anode from its lower side to its upper side. Here and in the following, the lateral direction refers to a direction perpendicular to the axial direction of the anode. Referring to Figure 3 showing the frame structure 48 of the SIP module. The frame structure 48 comprises a base element 50 which can be attached to the flange 16 by welding, brazing, soldering, screws or any other releasable con- nection means.. In other embodiments the flange 16 and the base 50 are inte- grally built or the base element 50 may be provided by the flange 16 itself. Connected to the base element 50 are in the example of Figure 3 two frame side elements 24 built as shoulder screws or posts which extend from the base element 50 to a top element 52. The NEG module 12 can be connected to the top element 52 by welding, brazing, soldering, screws or any other releasable connection means. During assembly, the anode 20 is fixed within the frame structure 48 and subsequently the frame structure 48 together with the anode 20 is connected to the flange 16. This is shown in Figures 4A and 4B. The anode 20 is connected in the frame structure 48 by a lower support element 71 pro- vided by an insulating element 62 connected to the anode 20. Further, an upper support element 73 is provided by an insulating element 74. Therein, the insu- lating elements 62, 74 are built by an insulating material such as a ceramic material. By the lower insulating support 71 the anode 20 is restricted from downward motion towards the flange 16 and might also be restricted by lateral motion, i.e. in one or more other directions or all other directions. By the upper support element 73, the anode 20 is restricted from upward motion and lateral motion, i.e. in one or more other directions or all other directions. The at least one support element 71, 73 or the two support elements 71, 73 may not fully restrict lateral movement allowing slight lateral movement of the anode while connecting the anode to the HV conductor 28 in order to facilitate mounting 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. In order to prevent motion of the anode 20 completely and fix the anode’s position in the frame structure, the anode 20 is connected to the HV conductor 28, extending through an opening in the base element 50, via a conducting sleeve 49, connecting the anode 20 with the HV conductor 28 of the vacuum feedthrough 26. Thus, by the lower support element 71, the upper support element 73 and the connection to the HV conductor 28 of the electrical feedthrough 26, the anode 20 is fixed in its position within the frame structure 48 of the SIP module 14. The steps for assembling the SIP module 14 thus comprise: a) providing a frame structure preferably comprising base element 50, one or more frame side elements 24 connected to the base element, and may also include a top element 52 connected to the respective frame side elements 24, b) inserting the anode and connecting the anode in the frame structure by the lower support element 71 and the upper support element 73, c) attaching the frame structure 48 together with the anode 20 to the flange 16, thereby connecting the anode 20 to the electrical feedthrough 26 and simultaneously fixing the position of the anode 20 in the SIP module 14, d) attaching the shell around the frame structure 48 as explained in more detail below. Referring to the figures 5A - 5C showing details of the shell of the vacuum pump 10. The shell of the vacuum pump 10 and in particular of the SIP module 14 comprises two individual shell elements 22. Therein, each shell element 22 is built identically in the present embodiment but the shell elements 22 may also be built / designed differently. Each shell element 22 comprises at least one mag- net 78, wherein in the example of Figures 5A – 5C each shell element 22 com- prises two magnets 78. Therein, the magnets 78 are arranged in a recession 79 of the shell element 22 in order to prevent lateral movement. The size of the recession 79 is adapted to the size of the magnets such that sidewalls of the recession 79 directly contact sidewalls of the respective magnets 78. The mag- nets 78 are attached to the respective shell elements 22 only by their magnetic force. No further fixing / fastening elements are present. Thus, the shell elements 22 serve as both pole pieces and the outer structure for 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 elements 22 are made from a magnetic material such as mild steel. The magnets 78 are neodymium (Nd) magnets or samarium (Sa) cobalt (Co) magnets. The magnets are attached with one surface to the shell element 22. An opposite surface of the magnets 78 is directly connected to the cathode 18. The cathode 18 is plate-shaped and covers the complete or substantially complete surface of the magnets 78. The cathode 18 may be made from titanium (Ti) or tantalum (Ta). The two shell elements 22 may comprise cathode elements 18, 18’ made from the same material or different material. In order to fix the cathode 18 in its position, bracket or clamping elements 80 are provided at the upper end and lower end of the respective magnets 78. The bracket elements 80 are held in place by the magnetic force of the magnets 78. No additional fixing elements are necessary. The bracket elements 80 comprise a chamfered surface 84 with a chamfer towards the magnets 78. Similarly, the cathode element 18 comprises chamfered edges 82 with a chamfer facing away from the magnets 78 and cor- responding to the chamfered surface 84 of the bracket elements 80. When at- taching the bracket element 80 to the side of the magnets 78, a clamping force is applied to the cathode 18 to fix the position of the cathode 18. The surface of the cathode element 18 flushes with the respective bracket element 80 and thus close positioning of the cathode element 18 to the anode 20 is feasible. Further, assembly and disassembly of the cathode elements 18 can be done without the need of additional tools. The two shell elements 22 resemble the outer shape of the SIP module 14. The shell elements 22 have openings 23 to 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. In order to have sufficient stability of the shell elements, the shell elements 22 provide at their axial edge an inden- tation 81 along an axial direction of the shell elements 22 which accommodates the frame side elements 24 when attached to them. Thus, by the corresponding shape of the indentations 81, the position of the elements 22 are defined by the position of the frame side elements 24. Referring to Figures 6A and 6B showing the NEG module 12 comprising a heater 32 with heating wire 86. The NEG module 12 comprises a base element 88 and top element 90, wherein NEG elements 34 are sleeved over the heater 32. The top element 90 and the base element 88 might be connected by NEG side ele- ments such as shoulder screws or posts. In particular the NEG side elements are built by threaded rods or posts. The electrical connection of the heater 32 is provided by an electrical connector 38 having connection elements 94. The connection elements 94 are shown in more detail in Figure 7. The connection elements 94 comprise a first end 96 and second end 98. Between the first end 96 and the second end 98 a collar or protruding feature 100 is present. Although shown in figure 7 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 also different diameters of the first end 96 and the second end 98 would be possible. Similarly, the example of Figure 7 shows a circular cross section wherein other shapes are of course also possible. The connector 38 comprises insulating elements 102, 106 as shown in Figures 8A and 8B. A first insulating element 102 has openings 104. Therein the number of openings 104 corresponds to the number of connecting elements 94. The diameter of the openings 104 corresponds to the diameter of the first end 96 and preferably the insulating elements 102 is made from a ceramic material. Similarly, the second insulating element 106 is made from a ceramic material. The second insulating element 106 is built by two halves, wherein Figure 8B shows only a single halve. By the two halves of the insulating element 106 openings 108 are established, wherein the diameter of the openings 108 corre- spond to the diameter of the second end 98 of the connecting element 94. The connecting element 94 is crimped or otherwise attached to the heating wire 86 of the heater 32. Subsequently the two halves of the second insulating element are inserted into a housing of the base element 88 of the NEG module 12 and sits on a shoulder 95. Therein, due to the protruding feature 100, the connecting elements 94 cannot fall through the openings 108 of the second insulating ele- ment 106. Subsequently, the first insulating element 102 is assembled by in- serting the first end 96 of the connecting elements 94 into the respective open- ings 104. Due to the protruding feature 100, the connecting elements 94 cannot fall out of the first insulating element 102. By a fixing element, for example provided by a set screw, the first insulating element 102 and the second insu- lating element 106 are fixed in their position. Thereby, no clamping force is directly acting on the connecting elements 94. Due to the protruding feature 100, the fixing element 94 is fixed in its axial position wherein a slight lateral movement of the connecting element 94 is still allowed and helps during assem- bly of the NEG module 12. Similar to the connector 38 connecting the NEG module 12 to the SIP module 14, a connector 40 is provided in order to connect the SIP module to the flange 16 as shown in Figures 4A and 4B. Thereby, an electrical lead 30 to be connected to the heater 32 runs from the flange 16 through the complete SIP module 14 and via the connector 38 to the NEG module 12. The electric lead 30 may com- prise two electrical wires 110, 110' which are surrounded by an insulating ma- terial such as a ceramic material. In the following it is referred to Figure 9 showing a sectional top view of the SIP module 14. The anode 20 has a first surface 114 and an opposite second surface 118, which correspond to the axial direction of the cylindric openings in the anode 20. The first surface 114 and the second surface 118 are connected by side surfaces 116, wherein the electrical lead 30 runs along a side surface 116 of the anode 20. Due to the position of the electrical lead 30, there is no direct line or line of sight 112 between the cathode element 18 and the electrical lead 30 preventing or at least reducing the likelihood of sputtering material of the cathode 18 onto the surface of the electrical lead 30 which may produce shorts. Thus, the electric lead 30 is protected by the anode 20 itself. Therefore, the side surface 116 of the anode may comprise indentations 120 which accommodate the electrical lead 30 and the respective wires 110, 110’ of the electrical lead 30. Thus, the low voltage supply of the heater 32 of the NEG module 12 is running from the connector 68 via the connecting element 40 and the electrical lead 30 across the SIP module 14 and in particular within the pole pieces of the SIP module provided by the shell elements 22 towards the connector 38 at the top element 52 of the SIP module and then further to the connector 38 and the heater 32. Thus, by the vacuum pump according to the present invention a combination of an NEG module and an SIP module is provided which can both be completely inserted into the vacuum chamber having a small cross-sectional area. At the same time, due to implementing a frame structure 48 and a shell, the process of assembling the SIP module 14 is simplified and the number of necessary parts in the vacuum can be reduced.

[0002] Reference List 10 vacuum pump 12 NEG module 14 SIP module 16 flange 18, 18’ cathode element 20 anode 22 shell element 23 openings 24 frame side element 26 vacuum feedthrough 28 HV conductor 30 electrical lead 32 heating element 34 NEG element 38 connector 40 connector 48 frame structure 49 conducting sleeve 50 base element 52 top element 62 insulating element 68 connector 71 lower support element 73 upper support element 74 insulating element 78 magnet 79 recession 80 bracket element 81 indentation 82 chamfered edge chamfered surface heating wire base element top element connection element shoulder first end fixing element second end protruding feature first insulating element opening second insulating element openings , 110’ electrical wire line of sight first surface side surface second surface indentation

Claims

CLAIMS 1. Sputter ion pump, SIP, module comprising a frame structure, an anode connected to the frame structure, and a shell connected to the frame structure, wherein the shell surrounds at least partially the frame structure and the anode, wherein the shell comprises at least one magnet and preferably at least one cathode element.

2. Sputter ion pump module according to claims 1, wherein the frame struc- ture comprises a base element and at least one or more frame side ele- ments connected to the base element.

3. Sputter ion pump module according to claim 2, wherein the frame structure comprises a top element, wherein the at least one or more frame side elements extend from the base element to the top element.

4. Sputter ion pump module according to claim 3, wherein the top element comprises openings to receive the at least one or more frame side elements and further comprising fixing elements to fix the position of the top element on the frame side element.

5. Sputter ion pump module according to any of claims 1 to 4, wherein the shell comprises two or more shell elements.

6. Sputter ion pump module according to claim 5, wherein the shell is cylindric and the shell elements are half-cylindric or part-cylindric.

7. Sputter ion pump module according to claims 5 or 6, wherein each shell element is built identically.

8. Sputter ion pump module according to any of claims 5 to 7, wherein each shell element comprises at least one magnet and at least one cathode el- ement.

9. Sputter ion pump module according to any of claims 5 to 8, wherein each shell element is built from a magnetic material and serves as pole piece.

10. Sputter ion pump module according to any of claims 5 to 9, wherein the shell elements are connected to each other by a magnetic force of the magnets.

11. Sputter ion pump module according to any of claims 5 to 10, wherein no additional fixing elements are present to attach the shell elements to the frame structure.

12. Sputter ion pump module according to any of claims 5 to 11, wherein the number of frame side elements corresponds to the number of shell ele- ments.

13. Sputter ion pump module according to any of claims 5 to 12, wherein at least one shell element comprises an indentation along an axial edge of the shell element to accommodate one of the frame side elements.

14. Vacuum pump comprising a sputter ion pump, SIP, module according to any of claims 1 to 13 and preferably an NEG pump module connected to the SIP module.

15. Vacuum pump according to claim 14, wherein an outer structure of the SIP module and / or an outer structure of the NEG module are cylindrical.

16. Vacuum pump according to any of claims 14 or 15, wherein an outer sur- face of the SIP module and outer surface of the NEG module flushes with each other.

17. Vacuum pump according to any of claims 14 to 16, comprising a flange, wherein the SIP module is connected with its first end to the flange, and / or wherein the NEG module and the SIP module are arranged within an area of a flange.

18. Vacuum pump according to any of claims 14 to 17, wherein the NEG mod- ule and / or the SIP module are completely arranged within the vacuum.

19. Method for assembly of an SIP module, preferably according to any of claims 1 to 13, including: Providing a frame structure; Providing an anode and fixing the anode within the frame structure; and Providing two or more shell elements of a shell and attaching the shell elements to the frame structure by a magnetic force.

20. Method according to claim 19, including no further steps of fastening the shell elements to the frame structure.

Images