Multi-arc ion source with variable magnetic field characteristic

Abstract

The invention belongs to the technical field of ion plating, and particularly relates to a multi-arc ion source with variable magnetic field characteristics. The multi-arc ion source comprises a cathode fixed on a cathode supporting seat; the magnet assembly is arranged on the side, back to the cathode, of the cathode supporting seat and comprises a first permanent magnet array and a rotating magnetic field generating device; the rotating magnetic field generating device comprises a second permanent magnet array, the second permanent magnet array is embedded into a center base, the center base is fixed to a center supporting rod, the center supporting rod is driven by an external driving mechanism to rotate so as to drive the second permanent magnet array to rotate relative to the central axis of the center base, and cathode magnetic field space distribution can change periodically. The mode that the permanent magnet array rotates to enable the magnetic field of the device to rotate is adopted, continuous movement of arc spots on the target surface is achieved, molten drop formation caused by too long staying time of the arc spots is reduced, meanwhile, interference of coil heating on discharge performance is eliminated, and the stability and efficiency of the multi-arc ion source are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of ion plating, and in particular relates to a multi-arc ion source with variable magnetic field characteristics. Background Art

[0002] As a key manufacturing process, thin-film deposition technology is widely used in a variety of fields, including aerospace, machinery manufacturing, electronics and information technology, interior decoration, new energy, and healthcare. Compared to traditional coating processes, ion plating offers numerous advantages, including denser films, uniform film thickness, strong bonding, high deposition efficiency, strong material adaptability, and low coating temperatures.

[0003] Among all the ion plating equipment currently in use, multi-arc ion source equipment has the characteristics of superior film performance, fast deposition speed and flexible process. In particular, the multi-arc ion source can use multiple cathodes of different materials to operate simultaneously, and can simultaneously coat multiple components or different parts of the same component, which significantly improves production efficiency. However, the multi-arc ion source also has problems such as a high proportion of large particle droplets and unstable arc discharge, which in turn affect the appearance quality, uniformity and mechanical properties of the film. In order to solve the above problems, the existing technology has carried out targeted improvements: the rotating magnetic field cathode arc source disclosed in CN109468598A uses an electromagnetic coil to generate a transverse rotating magnetic field, and controls the magnetic field strength by adjusting the input current to optimize the arc spot movement trajectory. However, this solution requires the continuous passage of a large current to maintain the electromagnetic field, resulting in a significant increase in the energy consumption of the equipment, and the heating problem of the coil may cause thermal deformation of the cathode body, thereby affecting the discharge stability. CN103643213A proposes a composite design that couples a rotating transverse magnetic field with an axial magnetic field. Arc spot trajectory control is achieved through a magnetic pole array and a three-phase excitation power supply system. However, the number of magnetic poles must strictly adhere to the rule of integer multiples of 4n or 3n, which limits the flexibility of magnetic field regulation, and the complex three-phase power supply system increases the difficulty of device control. CN1084426A uses a three-phase variable-frequency sinusoidal AC power supply to drive a multi-pole winding coil. The magnetic field rotation speed and intensity are controlled by coordinating the current frequency and voltage. However, the complex connection method of the enameled wire winding results in a cumbersome manufacturing process, and the continuous excitation of the external power supply still cannot avoid energy consumption and heat generation issues.

[0004] While these patented technologies have improved the motion characteristics of arc spots to varying degrees, none of them have broken through the technical framework for generating rotating magnetic fields with electromagnetic coils. They suffer from common drawbacks such as high energy consumption, complex structures, and difficult thermal management. Existing solutions all rely on external power supplies to dynamically adjust magnetic field parameters. Under high-frequency start-stop or variable operating conditions, delayed magnetic field response can lead to the risk of uncontrolled arc spots. Summary of the Invention

[0005] In response to the above technical problems, the present invention proposes a multi-arc ion source with variable magnetic field characteristics, which adopts the method of rotating the permanent magnet array itself to rotate the magnetic field of the equipment, replacing the traditional electromagnetic coil power supply mode. This design not only eliminates the interference of coil heating on the discharge performance, but also realizes precise mechanical control of the magnetic field rotation speed and direction through the inherent magnetic field characteristics of the permanent magnet, effectively suppressing the generation of large-particle molten droplets, and at the same time improving the stability of the arc discharge process, providing a magnetic field solution with both high efficiency and high reliability for multi-arc ion source equipment.

[0006] In order to ensure the smooth realization of the above technical goals, the technical solutions provided by this patent are as follows:

[0007] A multi-arc ion source with variable magnetic field characteristics, comprising:

[0008] The cathode is fixed on the cathode support;

[0009] A magnet assembly is provided on the side of the cathode support seat facing away from the cathode, comprising a first permanent magnet array away from the middle of the cathode support seat and a rotating magnetic field generating device located in the middle of the cathode support seat;

[0010] The rotating magnetic field generating device includes a second permanent magnet array, a central base and a central support rod. The second permanent magnet array is embedded in the central base, and the central base is fixed on the central support rod. The central support rod is driven to rotate by an external driving mechanism, thereby driving the second permanent magnet array to rotate relative to the central axis of the central base, causing the spatial distribution of the cathode magnetic field to change periodically.

[0011] Furthermore, the central base is fixedly connected to the central support rod by bolts.

[0012] Furthermore, the external driving mechanism is a servo motor or a stepping motor.

[0013] Furthermore, the permanent magnet is a magnetic steel. For example, the magnetic steel is a neodymium iron boron magnetic steel or a samarium cobalt magnetic steel.

[0014] Furthermore, the first permanent magnet array and the second permanent magnet array independently present a uniform magnetic field or a non-uniform magnetic field permanent magnet arrangement.

[0015] There are one or more first permanent magnet arrays. Further, there are multiple first permanent magnet arrays, which are symmetrical or asymmetrical relative to the central axis of the central base.

[0016] Furthermore, the first permanent magnet array is fixed on the outer ring magnetic base, and the outer ring magnetic base is structurally supported by the outer ring magnetic support body.

[0017] Furthermore, both ends of the cathode are fastened or clamped by cathode pressure rings, and the cathode pressure rings are fixed to the supporting flanges through sealing rings.

[0018] Furthermore, the multi-arc ion source further comprises an external electromagnetic coil, which is arranged on an external magnetic field support ring outside the cathode and is used to provide an auxiliary axial magnetic field.

[0019] During the operation of the multi-arc ion source, the central support rod is driven by an external driving mechanism to rotate, thereby causing the second permanent magnet array to rotate relative to the central axis of the central base, causing the spatial distribution of the cathode magnetic field of the multi-arc ion source to change periodically, thereby guiding the spatial distribution of charged particles and the spatial distribution of the magnetic field to change synchronously, avoiding the situation where the arc spot of the arc discharge stays at a certain place on the target surface for too long, and can effectively reduce the large particle droplets caused by heat accumulation on the target surface.

[0020] More preferably, during operation of the multi-arc ion source, the external electromagnetic coils are connected to industrial frequency AC power. By adjusting the voltage across the external electromagnetic coils, the amplitude of the current flowing through the external electromagnetic coils is controlled, thereby controlling the magnitude of the induced magnetic field generated by the external electromagnetic coils. Because the external electromagnetic coils are connected to an external AC power source, the spatial distribution of the induced magnetic field generated by the external electromagnetic coils also undergoes periodic variations, coupling with the magnetic field generated by the magnet assembly. This further improves the plasma distribution during the arc discharge process, reduces the generation of large droplets, and enhances the stability of the arc discharge process.

[0021] Compared with existing technologies:

[0022] The present invention uses a method in which the permanent magnet array rotates itself to rotate the magnetic field of the device, replacing the traditional electromagnetic coil power supply mode, causing the spatial distribution of the cathode magnetic field of the multi-arc ion source to change periodically. Under the action of the changing magnetic field, the spatial distribution of charged particles on the target surface of the multi-arc ion source will also show periodic spatial distribution changes. Through the above method, the arc spot can be continuously moved on the target surface, reducing the formation of droplets caused by the arc spot staying too long. This design not only eliminates the interference of coil heating on the discharge performance, but also realizes precise mechanical control of the magnetic field rotation speed and direction through the inherent magnetic field characteristics of the permanent magnet, effectively suppressing the generation of large-particle droplets, while improving the stability of the arc discharge process, and providing a magnetic field solution for multi-arc ion source equipment with both high efficiency and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure of a multi-arc ion source with a variable magnetic field.

[0024] The reference numerals are as follows:

[0025] 1. Support flange, 2. Outer magnetic field support ring, 3. Outer electromagnetic coil 4. Cathode, 5 Cathode compression ring, 6. Second permanent magnet array, 7. First permanent magnet array, 8. Sealing ring, 9. Outer ring magnetic base, 10. Cathode support seat, 11. Outer ring magnetic support body, 12. Center support rod, 101. Cathode support seat front seat, 102. Cathode support seat rear seat.

[0026] Figure 2 It is a multi-arc ion source non-uniform magnetic field configuration diagram.

[0027] Figure 3 It is a non-uniform magnetic field magnetic steel arrangement of the second permanent magnet array.

[0028] Figure 4 It is Figure 3 The non-uniform magnetic field distribution diagram before the second permanent magnet array rotates.

[0029] Figure 5 It is Figure 3 The non-uniform magnetic field distribution diagram after the second permanent magnet array rotates. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] As Figure 1As shown in the figure, a multi-arc ion source with a variable magnetic field comprises: a cathode 4 (target material) fixed on a cathode support seat 10; a magnet assembly arranged on the side of the cathode support seat 10 opposite to the cathode 4, comprising a first permanent magnet array 7 away from the middle part of the cathode support seat and a rotating magnetic field generating device located in the middle part of the cathode support seat; the rotating magnetic field generating device comprises a second permanent magnet array 6, a center base and a center support rod 12, the second permanent magnet array 6 is embedded in the center base, the center base is fixed on the center support rod, and the center support rod 12 is driven to rotate by an external driving mechanism to drive the second permanent magnet array 6 to rotate relative to the central axis of the center base, so that the spatial distribution of the magnetic field of the cathode 4 changes periodically. The center base is fixedly connected with the center support rod 12 by bolts. The permanent magnet is a magnetic steel. The first permanent magnet array 7 and the second permanent magnet array 6 respectively independently present a uniform magnetic field or a non-uniform magnetic field permanent magnet arrangement. The first permanent magnet array 7 is one or more. When the first permanent magnet array 7 is multiple, it is symmetrical or asymmetrical relative to the central axis of the center base. The first permanent magnet array 7 is fixed on an outer ring magnetic base 9, and the outer ring magnetic base 9 is structurally supported by an outer ring magnetic support body 11. The multi-arc ion source further comprises an external electromagnetic coil 3 arranged on an outer magnetic field support ring 2 at the periphery of the cathode 4, which is used to provide an auxiliary axial magnetic field. The outer magnetic field support ring 2 is fixed on a support flange 1 by bolts. Both ends of the cathode 4 are fastened or clamped by a cathode compression ring 5, and the cathode compression ring 5 is fixed on the support flange 1 by a sealing ring 8. The overall structure of the cathode compression ring 5 is a stepped fastener, which can center the two ends of the cathode 4, compress and fix the cathode 4. The cathode compression ring 5 and the sealing ring 8 are fixed by bolts. By tightening the bolts, the cathode compression ring 5 with the structure of the fastener compresses the cathode 4 to fix the cathode 4. The cathode support seat 10 comprises a cathode support seat front seat 101 and a cathode support seat rear seat 102, wherein the cathode support seat rear seat 102 is in close contact with the cathode 4, and the cathode support seat rear seat 102 is fixed with the support flange 1 by bolts.

[0032] The technical solutions are further described below in combination with specific embodiments. Figure 1 The technical solutions are further described below in combination with specific embodiments.

[0033] Embodiment 1

[0034] The first permanent magnet array is an integral whole, which together with the second permanent magnet array forms a non-uniform magnetic field configuration as shown in Figure 2 . The second permanent magnet array presents a non-uniform magnetic field magnetic steel arrangement (as shown in Figure 3 ). The non-uniform magnetic field distribution before and after the rotation of the second permanent magnet array is shown in Figure 4 and Figure 5 . The external electromagnetic coil is in the form of a solenoid.

[0035] When the multi-arc ion source is in operation, the cathode potential is -50 to -80 V, the anode is grounded, the operating current is 100 to 150 A, and an alternating current is supplied to the external electromagnetic coil with a current amplitude of 100 to 150 A. During operation, the central base where the second permanent magnet array of the multi-arc ion source is located rotates driven by the motor and gears, causing the spatial distribution of the magnetic field at the cathode (target surface) of the multi-arc ion source to change periodically. The periodically changing induced magnetic field generated by the external electromagnetic coil is superimposed on the static magnetic field generated by the first permanent magnet array, which can also cause the spatial distribution of the magnetic field on the target surface to show periodic changes. Under the action of the changing magnetic field, the spatial distribution of charged particles on the target surface of the multi-arc ion source will also show periodic spatial distribution changes. Through the above method, the arc spot can be continuously moved on the target surface, reducing the formation of molten droplets caused by the arc spot staying too long.

Claims

1. A multi-arc ion source with variable magnetic field characteristics, characterized in that: include: The cathode is fixed on the cathode support; A magnet assembly is provided on the side of the cathode support seat facing away from the cathode, comprising a first permanent magnet array away from the middle of the cathode support seat and a rotating magnetic field generating device located in the middle of the cathode support seat; The rotating magnetic field generating device includes a second permanent magnet array, a central base and a central support rod. The second permanent magnet array is embedded in the central base, and the central base is fixed on the central support rod. The central support rod is driven to rotate by an external driving mechanism, thereby driving the second permanent magnet array to rotate relative to the central axis of the central base, causing the spatial distribution of the cathode magnetic field to change periodically.

2. The multi-arc ion source according to claim 1, characterized in that: The central base is fixedly connected to the central support rod by bolts.

3. The multi-arc ion source according to claim 1, characterized in that The external driving mechanism is a servo motor or a stepping motor.

4. The multi-arc ion source according to claim 1, characterized in that: The permanent magnets constituting the permanent magnet array are magnetic steels.

5. The multi-arc ion source according to claim 4, characterized in that: The magnetic steel is a neodymium iron boron magnetic steel or a samarium cobalt magnetic steel.

6. The multi-arc ion source according to claim 1, characterized in that: The first permanent magnet array and the second permanent magnet array independently present a uniform magnetic field or a non-uniform magnetic field permanent magnet arrangement.

7. The multi-arc ion source according to claim 1, characterized in that: There are multiple first permanent magnet arrays, which are symmetrical or asymmetrical relative to the central axis of the central base.

8. The multi-arc ion source according to claim 1, characterized in that: The first permanent magnet array is fixed on an outer ring magnetic base, and the outer ring magnetic base is structurally supported by an outer ring magnetic support body.

9. The multi-arc ion source according to claim 1, characterized in that: The multi-arc ion source further comprises an external electromagnetic coil, which is arranged on an external magnetic field support ring around the cathode and is used to provide an auxiliary axial magnetic field.

10. The multi-arc ion source according to claim 1, characterized in that: Both ends of the cathode are fastened or clamped by cathode pressure rings, and the cathode pressure rings are fixed to the supporting flanges through sealing rings.

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