Magnetron with maintenance parts

Abstract

A magnetron (1) for bearing a cylindrical sputter target, the magnetron (1) comprising: a plurality of maintenance parts (20, 30), at least comprising a vacuum sealing means (30) and a coolant sealing means (20), and bearing means (16) for rotatably bearing the target, wherein each bearing means (16) is located outside of a region (113) axially extending from the vacuum sealing means (30) to the coolant sealing means (20).

Description

[0001] MAGNETRON WITH MAINTENANCE PARTS Technical field of the invention

[0002] The present invention relates to the field of magnetrons, and more specifically to end blocks for rotating cylindrical magnetrons.

[0003] Background of the invention

[0004] Rotating cylindrical magnetrons are widely used in sputtering applications for depositing thin films onto substrates. These systems rely on end blocks to perform several critical functions that ensure the proper operation of the magnetron. End blocks are responsible for providing adequate sealing for cooling fluids and maintaining a vacuum environment, facilitating the rotational drive of the cylindrical target, supporting and aligning the magnetic system, transferring power signals, bearing and supporting the target and magnetic components, and managing the injection and drainage of cooling fluids.

[0005] Over time and with extended use, the components within end blocks are subject to wear and degradation. This degradation can lead to reduced performance manifested as leaks of gases or fluids, increased friction, or higher torque requirements. Such issues not only affect the efficiency of the magnetron but can also compromise the quality of the sputtering process. To mitigate these problems, end blocks require periodic maintenance to inspect and potentially replace critical parts that are prone to wear.

[0006] Traditionally, maintenance of end blocks has posed significant challenges. The complex nature of these components necessitates a level of expertise that is not always readily available on-site. As a result, end blocks or substantial portions thereof may be sent back to the supplier for maintenance and testing. This process is both costly and time-consuming, leading to extended downtime and reduced productivity. Alternatively, on-site maintenance requires specialized training for personnel, the availability of specific tools for disassembly and reassembly, and a substantial inventory of spare parts. Even with these measures in place, there remains a risk of misalignment or assembly errors, which can adversely affect the performance of the magnetron after maintenance.Additionally, as sputtering technology has evolved, there has been a shift from planar to rotating cylindrical magnetrons in various applications, including large-area inline glass coaters used in architectural glass and other industries where high throughput and long interrupted stable production campaigns are advantageous. Retrofitting existing systems to accommodate rotating cylindrical magnetrons can introduce further complications with respect to maintenance.

[0007] Despite advancements in magnetron design and maintenance practices, significant challenges remain. Maintenance procedures can still be lengthy and require specialized knowledge, and the potential for performance issues following maintenance persists.

[0008] There is, therefore, a continuing need for improvements in the design and maintenance of end blocks for rotating cylindrical magnetrons to address these challenges more effectively.

[0009] Summary of the invention

[0010] It is an object of embodiments of the present invention to facilitate maintenance of a magnetron for bearing a cylindrical sputter target.

[0011] The above objective is accomplished by a magnetron according to the present invention.

[0012] It is an advantage of embodiments of the present invention that the vacuum sealing means and coolant sealing means can be removed from the same side without having to remove the bearing means due to the bearing means being located outside of the region between the vacuum sealing means and the coolant sealing means.

[0013] It is an advantage of embodiments of the present invention that maintenance of the magnetron may vastly simplified, as removal and replacement of the bearing means may not be required when replacing the sealing means, which typically involves more complex procedures performed by trained personnel. A further advantage of embodiments of the present invention is that the maintenance is cheaper since the bearing means are the more expensive parts compared to the sealing means. As, typically, they don’t need to be demounted during the maintenance process, they typically stay in good condition and do not need to be replaced unnecessarily.In a first aspect, the present invention relates to a magnetron for bearing a cylindrical sputter target, the magnetron comprising a plurality of maintenance parts, at least comprising a vacuum sealing means and a coolant sealing means, and bearing means for rotatably bearing the target, wherein each bearing means is located outside of a region axially extending from the vacuum sealing means to the coolant sealing means.

[0014] In other words, typically, no bearings are located in said region, e.g., between the vacuum sealing means and the coolant sealing means. This may facilitate removal and / or replacement of all seals of the magnetron without disassembling the bearings. That is, typically, all bearing means are located outside of said region extending from the vacuum sealing means to the coolant sealing means.

[0015] In embodiments, the axial direction is a direction along a cylindrical or rotation axis of the cylindrical sputter target, when the target would be assembled in the magnetron. The region axially extending from the vacuum sealing means to the coolant sealing means therefor may be understood to be a region along said cylindrical or rotation axis, extending - in a direction along said cylindrical or rotation axis - from the vacuum sealing means to the coolant sealing means.

[0016] In embodiments, the bearing means and the maintenance parts comprise the bearing means and maintenance parts, e.g., all the bearing means and maintenance parts, located at a first axial side of the target. In embodiments, the bearing means and the maintenance parts do not comprise any bearing means and any maintenance parts located (e.g., that may be present) at a second axial side (different from the first axial side) of the target. (In other words, in embodiments, although additional bearing means or additional maintenance parts may be present at said second axial side of the target, those additional bearing parts or additional maintenance parts are typically not considered to be comprised in the bearing means and the maintenance parts, located at the first axial side of the target.) In embodiments, the bearing means are arranged for supporting the cylindrical sputter target at a first end of the target. In these embodiments, the bearing means are typically located at the first axial side (thatis, the region located along the axial direction extending from the first end of the target) of the cylindrical sputter target. The maintenance part, e.g., at least the vacuum sealing means and the coolant sealing means, are typically located at said first axial side of the cylindrical sputter target as well.

[0017] In embodiments, the vacuum sealing means and the coolant sealing means may be located at a first side of a radial plane, and the bearing means are located at a second side of said radial plane, wherein the magnetron is arranged for bearing, or carrying, the target, if present, at said first side. In embodiments, the magnetron contains a carrying element, such as a flange, to which the target may be attached, at said first side. The radial plane is typically a plane perpendicular to the cylindrical or rotation axis of the cylindrical sputter target, if the target would be assembled in the magnetron. It is an advantage of these embodiments that removal of both the vacuum sealing means and coolant sealing means from a same side without having to remove the bearings may be enabled, vastly simplifying maintenance of the magnetron, as removal and replacement of bearing means typically requires more involved steps that must be performed by trained personnel. Typically, the maintenance becomes also cheaper because the bearing means do not need to be replaced unnecessarily. Furthermore, in these embodiments, only disassembly from a single side of the magnetron is required when replacing maintenance parts. Other maintenance parts, different from the bearings, are preferably located at said first side for facilitating their maintenance and / or replacement as well. In embodiments, any maintenance part, different from the bearings, may independently be located at said first side.

[0018] In embodiments, the magnetron may further comprise driving means for driving a rotation of the cylindrical sputter target, wherein the driving means are located at said second side. The driving means may contain at least first gears coupled to a rotation axis coupled to the target. In embodiments, the first gears are located at the second side. The driving means may be coupled to second gears fixed on a shaft coupled to an actuator for inducing rotational motion to the shaft, and then, via the gears, to the target, if present. In embodiments, the shaft, when present, to which the second gears may be fixed is located at the second side. This ensures that said driving means or the first gears do not haveto be disassembled when the sealing means are to be replaced, further facilitating replacement of said sealing means.

[0019] In embodiments, an end of the magnetron housing at said second side may be closed. As all maintenance is to be performed from the first, target, side of the magnetron, it is advantageous to close the second side, away from the target side, facilitating sealing and material integrity at the second side of the end block. This is particularly advantageous in configurations wherein the second side is not well accessible. This may, for example, be the case when retro-fitting the magnetron into an existing set-up in which the second side, or backside, of the magnetron, may be substantially inaccessible.

[0020] In embodiments, the maintenance parts further comprise means for transferring power to the target, if said target is present. Said means for transferring power may comprise a conductive brush, such as a carbon brush. The power transferring means may be located at the first side of the radial plane.

[0021] In some embodiments, the maintenance parts further comprise the bearing means. In embodiments, the magnetron may comprise a maintenance cassette containing the bearing means. In these embodiments, the bearing means are preferably provided in a different maintenance cassette than the coolant and vacuum sealing means, although this is not essential. The lifetime of bearing means is typically much longer than that of sealing means, so that it is preferred that simultaneous replacement - which may be required when the bearing and sealing means are located in the same cassette - is not needed. However, in different embodiments, the bearing means are not amongst the maintenance parts. In embodiments, the bearing means are not provided in a maintenance cassette.

[0022] In embodiments, the magnetron may comprise one or more maintenance cassettes, each maintenance cassette comprising one or more of said plurality of maintenance parts. The magnetron may comprise two or more maintenance cassettes. In embodiments, each maintenance cassette may contain a single maintenance part. In embodiments, each of the vacuum sealing means and the coolant sealing means is contained in a different, e.g., dedicated, maintenance cassette. Alternatively, multiple maintenance parts may be comprised in a single maintenance cassette. The vacuum and coolant sealing means may becontained in a same maintenance cassette. In embodiments, the magnetron may comprise a maintenance cassette containing the power transferring means. The power transferring means may be contained in the maintenance cassette containing the vacuum sealing means and / or the coolant sealing means. The power transferring means may be contained in a dedicated maintenance cassette. Other maintenance parts may be provided in maintenance cassettes as well, e.g., in dedicated maintenance cassettes each only for a single maintenance part or combined with one or more other maintenance parts in a maintenance cassette. The maintenance cassettes may alternatively be called maintenance cartridges or unitary maintenance cartridges. Each maintenance cassette may contain a support structure for supporting each maintenance part of the maintenance cassette. The support structure may be formed of a rigid material, e.g., a metal. In embodiments, each support structure comprises a substantially cylindrically symmetric-shaped rigid body, e.g., such as a ring. A cross-section of the support structure, in a radial plane, may have an annular shape. These embodiments are advantageous as they facilitate moving the cassette axially into, or out of, a housing of the magnetron.

[0023] The maintenance cassette may comprise first engaging means, configured for engaging with second engaging means of the magnetron for fixing, e.g., rigidly fixing, the support structure, and thus the maintenance cassette, in the magnetron. Said engaging means of the maintenance cassette may be adapted for holding or fixing the maintenance cassette in place.

[0024] In embodiments, the vacuum sealing means and the coolant sealing means may comprise dynamic seals. The dynamic seals allow for rotational movement of components, between which the seals are located, with respect to each other. Sealing means contained in a maintenance cassette are typically static, rather than dynamic, with respect to the maintenance cassette itself, such as with respect to the support structure of the maintenance cassette. The sealing means of the maintenance cassette may be fixedly or immovably attached to the support structure. The sealing means may, however, be dynamic or movable with respect to other components, not contained in the maintenance structure, of the magnetron.Each sealing means may contain multiple seals, which may be located axially shifted with respect to each other. Seals may be any type of seal suitable for separating two adjacent volumes (e.g., filled with liquid or gas). Most common types of seals contain elastomers (e.g., lip seals) or close contact finished surfaces (e.g., mechanical seals), although the invention is not limited to any type of seal. For example, the seals may contain hybrid embodiments. In embodiments, each vacuum sealing means may contain one or more, e.g., two or more, vacuum seals. A sensor may be provided between the two or more seals for sensing whether the seals are leaking. In embodiments, each coolant sealing means may contain one or more, e.g., two or more, coolant seals. A cross-section of each seal, in a radial plane, may have an annular shape. The multiple seals of each sealing means may be located on the same maintenance cassette, facilitating replacement of the sealing means. In embodiments, a first maintenance cassette may comprise each seal of the vacuum sealing means, and a second maintenance cassette may comprise each seal of the coolant sealing means. However, this is not required, and instead, different seals of the same sealing means may be located on different maintenance cassettes.

[0025] In embodiments, a radial plane may intersect with both a vacuum seal of the vacuum sealing means and a coolant seal of the coolant sealing means. Having both sealing means radially spaced, may simplify the integration of the sealing means into a single and (axially) compact maintenance cassette. Furthermore, magnetron depth (along the target axis) is often a critical dimension as to allow making the target as large as possible for generating a uniform coating on an as wide as possible substrate being positioned under or passing under the cylindrical sputtering target. Having radially placed functionalities may allow making the magnetron housing more compact. In embodiments, within said radial plane, an inner radius of the vacuum seal may be larger than an inner radius of the coolant seal. In embodiments, within said radial plane, the inner radius of the vacuum seal may be larger than an outer radius of the coolant seal. In alternative embodiments, the relative size of the sealing means may be inversed, e.g., having an outer radius of the vacuum seal being smaller than an inner radius of the coolant seal.In embodiments, a cylindrical axis of the vacuum sealing means may be parallel to, preferably substantially coincides with, a cylindrical axis of the coolant sealing means. As the bearing means are for rotatably bearing the target, the bearing means preferably have a rotation axis parallel to, or coinciding with, a rotation axis of the target. In embodiments, a cylindrical axis of the bearing means may be parallel to, preferably substantially coincides with, a symmetry axis of the vacuum sealing means and of the coolant sealing means. The cylindrical axis of the vacuum sealing means may be parallel to, preferably substantially coincides with, the cylindrical axis of the target, if present. The cylindrical axis of the coolant sealing means may be parallel to, preferably substantially coincides with, the cylindrical axis of the target, if present. The cylindrical axis of the bearing means may be parallel to, preferably substantially coincide with, the cylindrical axis of the target, if present.

[0026] In embodiments, the magnetron may be arranged so that the vacuum and coolant sealing means, preferably each maintenance part or maintenance cassette, is axially removable from the magnetron, e.g., from the housing. In embodiments, the magnetron may be arranged so that the vacuum and coolant sealing means are axially removable from a same side of the magnetron, e.g., of the housing, preferably arranged so that each maintenance part or maintenance cassette is removable from said same side. In embodiments of the present invention, e.g., by having the sealing means at the same side of the radial plane as the side at which the target, if present, is carried, removal and replacement of the sealing means as well as the target may be performed from a same side. This is particularly advantageous if the magnetron is positioned within a sputtering setup such that only the target side of the magnetron is easily reachable.

[0027] In preferred embodiments, the magnetron may be arranged so that the vacuum and coolant sealing means, preferably each maintenance part or maintenance cassette, is axially removable from the magnetron without disassembling the bearing means, if present, and without disassembling the driving means, if present. The arrangement of the present invention may facilitate removal of the sealing means without removing any bearing means and driving means, if present. As the bearing means and the driving means have tobe maintained typically only once in e.g. every 5 years or more, whereas sealing means are to be replaced typically every one to three years, maintenance may be more efficient when the former may be kept in place in the magnetron while only the latter ones are to be disassembled.

[0028] In embodiments, the magnetron may be an end-block. The magnetron, e.g., the end-block, may be arranged for bearing, or rotatably bearing, the cylindrical sputter target. In embodiments, the magnetron comprises the cylindrical sputter target. The magnetron or end-block may comprise an inlet and outlet for circulating a coolant, such as water, through the magnetron or endblock, and through and the target, if present. The coolant sealing means may ensure that said coolant does not leak from the magnetron.

[0029] Any features of any embodiment of the first aspect may be independently as correspondingly described for any embodiment of any of the other aspects of the present invention.

[0030] In a second aspect, the present invention relates to the use of the magnetron of any embodiments of the first aspect for sputtering, e.g. , magnetron sputtering.

[0031] Any features of any embodiment of the second aspect may be independently as correspondingly described for any embodiment of any of the other aspects of the present invention.

[0032] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims.

[0033] Although there has been constant improvement, change and evolution of devices in this field, the present concepts are believed to represent substantial new and novel improvements, including departures from prior practices, resulting in the provision of more efficient, stable and reliable devices of this nature.The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

[0034] Brief description of the drawings

[0035] FIG. 1 is an exploded view of a magnetron in accordance with embodiments of the present invention.

[0036] FIG. 2 is a cross-sectional view of a magnetron in accordance with embodiments of the present invention, with the maintenance cassettes axially removed from the magnetron.

[0037] FIG. 3 is a cross-sectional view of a magnetron in accordance with embodiments of the present invention, with the maintenance cassettes installed in the magnetron.

[0038] In the different figures, the same reference signs refer to the same or analogous elements.

[0039] Description of illustrative embodiments

[0040] The present invention will be described with respect to particular embodiments and with reference to certain drawings, but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0041] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

[0042] It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. The term “comprising” therefore covers the situation where only the stated features are present and the situation where these features and one or more other features are present. The word “comprising” according to the invention therefore also includes as one embodiment that no further components are present. Thus, the scope of the expression “a device comprising means A and B” should not be interpreted as being limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0043] Similarly, it is to be noticed that the term “coupled”, also used in the claims, should not be interpreted as being restricted to direct connections only. The terms “coupled” and “connected”, along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Thus, the scope of the expression “a device A coupled to a device B” should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. “Coupled” may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other.

[0044] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0045] Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0046] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0047] Furthermore, some of the embodiments are described herein as a method or combination of elements of a method that can be implemented by a processor of a computer system or by other means of carrying out the function. Thus, a processor with the necessary instructions for carrying out such a method or element of a method forms a means for carrying out the method or element of a method. Furthermore, an element described herein of an apparatus embodiment is an example of a means for carrying out the function performed by the element for the purpose of carrying out the invention.In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0048] In a first aspect, the present invention relates to a magnetron for bearing a cylindrical sputter target, the magnetron comprising a plurality of maintenance parts, at least comprising a vacuum sealing means and a coolant sealing means, and bearing means for rotatably bearing the target, wherein each bearing means is located outside of a region axially extending from the vacuum sealing means to the coolant sealing means.

[0049] In a second aspect, the present invention relates to the use of the magnetron of any embodiments of the first aspect for sputtering.

[0050] The invention will now be described by a detailed description of several embodiments of the invention. It is clear that other embodiments of the invention can be configured according to the knowledge of persons skilled in the art without departing from the technical teaching of the invention, the invention being limited only by the terms of the appended claims.

[0051] Reference is made to FIG. 1 , which is an exploded view of an exemplary magnetron 1, in the present example, an end-block 1, in accordance with embodiments of the present invention.

[0052] The end-block 1 contains a housing 6 containing an open end 61 , which is the side on which the target (not shown) may be mounted on the end-block. Through said open end 61 , different parts 2, 3, 4, 5 may be axially (e.g., along a central, e.g., cylindrical or rotational, axis of the target) moved into the housing 6. Each of the different parts 2, 3, 4, 5 is now described, in the order in which they are installed in the housing 6. When installed, they may be removed from the housing 6 in the opposite order.

[0053] Firstly, the end-block 1 of the present example contains a collector block 5. The collector block 5 may contain a ducting system 51 for supplying anddraining cooling fluid to and from the target, when mounted. The atmospheric side of the end-block 1 typically has two connectors for attaching hoses: one for input and one for the outlet of the coolant. The collector block 5 will reroute the flow path of the coolant as to be compatible with the cylindrical target, when mounted. In the case the cylindrical target is mounted and in rotation, continuous and separated coolant delivery and extraction needs to be foreseen independent of the angular position of the target. In a specific embodiment, the collector block 5 may have an annular configuration in which a central circular / cylindrical zone provides one direction of the coolant while being surrounded by a wider circumfering, or encircling, circular / cylindrical zone providing the opposite direction of the coolant. The collector block 5 may additionally contain electronic components 52, such as, but not limited to: sensors, or controllers for sensors, for detecting a temperature, pressure, or humidity; a controller for controlling magnets of the target, if present; and a controller for controlling power provided to the target. The lifetime of all of these functionalities and components is typically very long so that typically little or no maintenance to the collector block 5 is required. Updates to the potentially present electronics contained in the collector block 5 may, however, be occasionally desired, though this does not necessarily require the removal of this unit.

[0054] Secondly, the end-block 1 of the present example contains a cassette 4 containing driving means, in particular, first gears 40. The first gears 40 may, when installed in the housing 6 of the magnetron 1 , interact with second gears 71 on a shaft extending from the housing to an actuator. The actuator may induce a rotation of said shaft for inducing, via the gears 40, a motion or rotation of the target. The cassette 4 further contains a sealing surface 41 about an outer surface of the cassette 4 for interacting with vacuum seal means 30 of a maintenance cassette 3 comprising said vacuum sealing means 30. The cassette 4 further contains bearing means (not shown). The sealing surface 41 and the bearing typically require less maintenance than the sealing means, e.g. every about 5 years. The magnetron 1 may be configured so that the cassette 4 can be removed from the housing 6 without removing the collector block 5, so that the cassette 4 may be removed from the magnetron 1 without disassembling the collector block 5 that requires less maintenance.Thirdly, the end-block 1 of the present example contains said maintenance cassette 3 comprising said vacuum sealing means 30 comprising a plurality of vacuum seals along an inner surface of the maintenance cassette. As indicated above, the vacuum sealing means 30 are for providing a dynamic sealing with the sealing surface 41 of the cassette 4. The vacuum sealing means 30 are typically arranged for fluidically separating an atmosphere within a sputter chamber, in which the end-block 1 and the target are typically mounted for sputtering inside said sputter chamber, from an atmosphere outside said sputter chamber. The vacuum sealing means are typically adapted for maintaining a vacuum atmosphere inside the sputter chamber. The lifetime of the vacuum sealing means 30 is rather short and these vacuum sealing means 30 have to be checked regularly, e.g., every 1 or 2 or 3 years. The end-block 1 is configured so that the maintenance cassette 3 may be removed without removing the cassette 4 or collector block 5.

[0055] Fourthly, the end-block 1 of the present example contains a maintenance cassette 2 comprising coolant sealing means (not visible) at an inner surface of the cassette 2, and comprising a plurality of coolant seals. The coolant sealing means are typically arranged for fluidically separating an atmosphere within a sputter chamber, in which the end-block 1 is mounted, from cooling fluid (e.g., water) for cooling the cylindrical sputter target. The coolant sealing means are typically arranged for sealing the coolant, i.e., cooling fluid, within a coolant channel of the magnetron, for example, for preventing leakage of the coolant, i.e., cooling fluid, into the sputter chamber or different regions (e.g., specific regions that may contain gears, electronics or other components) within the end block housing. The end-block 1 is configured so that the maintenance cassette 2 may be removed without removing the maintenance cassette 3, the cassette 4 and the collector block 5. The maintenance cassette 2 has to be checked about as often as the maintenance cassette 3, and both can be checked, removed and replaced without removing any of the other components of the end-block. Although the present example provides a particular order in which the components 2, 3, 4, 5 may be inserted or removed from the magnetron 1, the order for in particular the maintenance cassettes 2, 3 may be inverted, so thatthese the maintenance cassettes 2, 3 may be removed without removing the cassette 4 and collector block 5.

[0056] Reference is made to FIG. 2, which is a vertical cross-sectional view of the end-block 1. The central axis 10, which is the central, cylindrical or rotational axis of the target (not shown) is indicated by the dashed line 10. In FIG. 2, the control block and the cassette containing driving means 40 are shown installed in the housing 6 of the end-block. The maintenance cassettes 2 and 3 are shown axially removed, i.e., moved along axis 10, from the housing 6.

[0057] In the present example, maintenance cassette 3 contains said vacuum sealing means 30, in particular, two vacuum seals, at an inner surface of the cassette 3. In particular, in the present example, the maintenance cassette 3 contains a rigid, ring-shaped support structure 31. This ring-shaped support structure 31 allows for facile removal and re-installation of the maintenance cassette 3. The vacuum sealing means are, in the present example, provided at an inner surface of said support structure 31. A sensor may be provided between the two vacuum seals of the vacuum sealing means 30 for sensing whether the vacuum seals require maintenance or replacement, e.g., provide good sealing or have worn.

[0058] The end-block 1 contains a cavity 13 for receiving the maintenance cassette 3, wherein the cavity contains the sealing surface 41 for interacting with the vacuum sealing means 30. Furthermore, the maintenance cassette 3 contains first engaging means 32 for engaging with second engaging means 14 contained in the housing 1. In particular, in the present example, the second engaging means 14 are adapted for receiving the first engaging means 32 for rigidly fixing the maintenance cassette 3 to the housing 1 , in such a way that the vacuum sealing means 30 contact the sealing surface 41 for providing a dynamic vacuum seal.

[0059] Similarly, maintenance cassette 2, containing the coolant sealing means 20, contains two coolant seals at an inner surface of the maintenance cassette 2, in particular, at an inner surface of a rigid, ring-shaped support structure 21 of the maintenance cassette 2. A sensor may be provided between the two coolant seals of the coolant sealing means 20 for sensing whether the coolant seals require maintenance or replacement, e.g., provide good sealing or haveworn. The housing 6 contains a cavity 15 for axially receiving the maintenance cassette 2.

[0060] Reference is made to FIG. 3, in which the maintenance cassettes 2 and 3 are installed in the housing 6, i.e., in the magnetron 1.

[0061] When installed, the coolant sealing means 20 - that is, the coolant seals thereof - and the vacuum sealing means 30 - that is, the vacuum seals thereof - are located within a region 113 extending along axis 10. In other words, the region 113 extends axially (i.e., along axis 10) from the coolant sealing means 20 to the vacuum sealing means 30. Within said region 113, the end-block 1 contains no bearings 16. In the present example, the bearings 16 of the endblock 1 that are for rotatably bearing the target are located outside of said region 113. In the present example, the bearings 16 of the end-block 1 having a central axis, or axis of rotation, around the central axis 10 are located outside of said region 113. In the present example, a radial plane 12 (perpendicular to said central axis 10) intersects with both the vacuum sealing means 30 and the coolant sealing means 20. In the present example, a radial plane 12 (perpendicular to said central axis 10) intersects with both a vacuum seal of the vacuum sealing means 30 and a coolant seal of the coolant sealing means 20.

[0062] In the present example, the sealing means 20, 30 are located at a first side 111 of a radial plane 11, said radial plane 11 being perpendicular to the axis 10, and the bearings 16 are located at a second side 112 of said radial plane 11, said second side 112 being opposite to said first side 111. In the present example, the target (not shown) is to be mounted at the first side 111 of said radial plane 11. Also the first gears 40 of the are located at said second side 112.

[0063] In the present example, an end 60 of the magnetron housing 6 at said second side 112 is closed. The open side 61 of the housing, through which the maintenance cassettes may be removed or replaced into the housing 6, is located at said first side 111.

[0064] In the present example, this configuration facilitates removal of the sealing means 20, 30 from the end-block 1 without removing the bearings 16 from the end-block 1. Removing the bearings 16 and placing them back is typically not done during maintenance. During the removal operation, thebearings can be damaged by the removal force often transmitted over the rolling element. There is also the risk that the bearings get contaminated. Therefore, it is preferred that the bearings 16 do not need to be removed when checking or replacing the sealing means 20, 30.

[0065] In the present example, a central or cylindrical axis of the vacuum sealing means 30 is coincides with a central or cylindrical axis of the coolant sealing means 20. In the present example, the cylindrical axis of the vacuum sealing means 30 and the cylindrical axis of the coolant sealing means 20 coincide with the central axis 10.

[0066] Furthermore, in the present example, the central or cylindrical axis of the bearing means 16 coincides with a symmetry axis of the vacuum sealing means 30 and of the coolant sealing means 20. Typically, the cylindrical axis of the bearing means 16 coincides with the central axis 10.

[0067] More parts requiring revision / maintenance may be present in the magnetron, e.g., power transferring means or signal transferring means, that may benefit from the same concept as demonstrated for the vacuum sealing means 30 and the coolant sealing means 20. In the proposed embodiments, said power and / or signal transferring means may be embedded in the maintenance cassette 2 or 3.

[0068] The configuration of the present example facilitates removal of the sealing means 20, 30 from the end-block 1 without removing the cassette containing the first gears 40 from the end-block 1. Removing the first gears 40 requires, in the present example, the removal of shaft 7 with second gears 71 from the housing 6. Therefore, it is preferred that the first gears 71 remain in place when checking or replacing the sealing means 20, 30.

[0069] It is to be understood that although preferred embodiments, specific constructions and configurations, as well as materials, have been discussed herein for devices according to the present invention, various changes or modifications in form and detail may be made without departing from the scope of this invention. Steps may be added or deleted to methods described within the scope of the present invention.

Claims

CLAIMS1.- A magnetron (1) for bearing a cylindrical sputter target, the magnetron (1) comprising:a plurality of maintenance parts (20, 30), at least comprising a vacuum sealing means (30) and a coolant sealing means (20), andbearing means (16) for rotatably bearing the target, wherein each bearing means (16) is located outside of a region (113) axially extending from the vacuum sealing means (30) to the coolant sealing means (20).2.- The magnetron (1) of claim 1, wherein the vacuum sealing means (30) and the coolant sealing means (20), preferably all maintenance parts (20, 30), are located at a first side (111 ) of a radial plane (11 ), and the bearing means (16) are located at a second side (112) of said radial plane (11), wherein the magnetron (1) is arranged for bearing the target, when present, at said first side (111).3.- The magnetron of claim 2, further comprising driving means (40) for driving a rotation of the cylindrical sputter target, wherein the driving means (40) are located at said second side (112).4.- The magnetron (1) of any of claims 2 or 3, wherein an end (60) of the magnetron housing (6) at said second side (61) is closed.5.- The magnetron (1) of any of the previous claims, comprising one or more maintenance cassettes (2, 3), each maintenance cassette (2,3) comprising one or more of said plurality of maintenance parts (20, 30).6.- The magnetron (1) of claim 5, wherein each maintenance cassette (2, 3) contains a support structure (21, 31) for supporting each maintenance part (20, 30) of the maintenance cassette (2, 3).7.- The magnetron (1) of claim 6, wherein each support structure (21, 31) comprises a substantially ring-shaped rigid body (21, 31).8.- The magnetron (1) of any of the previous claims, wherein a cylindrical axis of the vacuum sealing means (30) is parallel to, preferably substantially coincides with, a cylindrical axis of the coolant sealing means (20).9.- The magnetron (1) of any of the previous claims, wherein a cylindrical axis of the bearing means (16) is parallel to, preferably substantially coincides with, a symmetry axis of the vacuum sealing means (30) and of the coolant sealing means (20).10.- The magnetron (1) of any of the previous claims, arranged so that the vacuum (30) and coolant sealing means (20), preferably each maintenance part (20, 30), is axially removable from the magnetron (1) without displacement or disassembling the bearing means (16), if present, and without displacement or disassembling the driving means (40), if present.11.- The magnetron (1) of any of the previous claims, arranged so that the vacuum (30) and coolant sealing means (20) are axially removable from a same side (111) of the magnetron, preferably arranged so that each maintenance part (20, 30) is removable from said same side.12.- The magnetron (1) of any of the previous claims, wherein the vacuum sealing means (30) and the coolant sealing means (20) comprise dynamic seals.13.- The magnetron (1) of any of the previous claims, wherein a radial plane (12) intersects with both a vacuum seal of the vacuum sealing means (30) and a coolant seal of the coolant sealing means (20).14.- The magnetron (1 ) of any of the previous claims, wherein the magnetron (1) is an end-block (1).15.- Use of the magnetron (1 ) of any of the previous claims for sputtering.

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