Target cathode with rotatable central magnetic field and magnetron sputtering coating device

Abstract

The invention discloses a central magnetic field rotatable target cathode and a magnetron sputtering coating device, and relates to the technical field of magnetron sputtering, the central magnetic field rotatable target cathode comprises a target material, a first column magnet, a second column magnet and a rotation driving device, the front surface of the target material is used for colliding with charged particles for sputtering; the multiple first column magnets are sequentially arranged on the back side of the target material along the first circumference, the first circumference and the target material are coaxial, and the magnetic poles of the sides, close to the target material, of all the first column magnets are the same; the number of the second column magnet is one, and the second column magnet is arranged on the back side of the target material; the magnetic pole of one side, close to the target material, of the second column magnet is opposite to the magnetic pole of one side, close to the target material, of the first column magnet; the rotation driving device is used for driving the second column magnet to rotate around the central axis of the first circumference. And the utilization rate and the sputtering rate of the target material are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetron sputtering, and particularly to a target cathode with a rotatable central magnetic field and a magnetron sputtering coating device. Background Art

[0002] Magnetron sputtering coating is a coating technology that uses a coating material as a target cathode. By bombarding the target with argon ions, cathode sputtering is generated, and the target atoms are sputtered onto the workpiece to form a deposition layer. The coating material always remains solid and does not form a molten pool. As an important surface treatment technology, magnetron sputtering coating technology will play an increasingly important role in future technological development and has become an important means for depositing wear-resistant, corrosion-resistant, decorative, optical and other various functional thin films. Magnetron sputtering coating technology will continuously incorporate more advanced scientific and technological elements to meet more complex and high-precision coating requirements.

[0003] Due to the magnetic field distribution factor, the existing target cathodes have low target material utilization rate and low sputtering rate, and it is impossible to achieve large-area, uniform and rapid deposition of thin films. Summary of the Invention

[0004] The purpose of the present invention is to provide a target cathode with a rotatable central magnetic field and a magnetron sputtering coating device to solve the problems existing in the above-mentioned prior art and improve the utilization rate of the target material and the sputtering rate.

[0005] To achieve the above purpose, the present invention provides the following solutions: The present invention provides a target cathode with a rotatable central magnetic field, including: a target material, a plurality of first columnar magnets, a second columnar magnet and a rotation driving device. The front surface of the target material is used for colliding with charged particles for sputtering. There are a plurality of first columnar magnets, and the plurality of first columnar magnets are sequentially arranged along a first circumference on the back side of the target material. The first circumference and the target material are coaxial, and the magnetic poles of all the first columnar magnets on the side close to the target material are the same. There is one second columnar magnet, and the second columnar magnet is arranged on the back side of the target material. The second columnar magnet is eccentrically arranged within the first circumference, and the magnetic pole of the second columnar magnet on the side close to the target material is opposite to the magnetic pole of the first columnar magnet on the side close to the target material. The rotation driving device is used to drive the second columnar magnet to rotate around the central axis of the first circumference.

[0006] Preferably, a cooling cavity is constructed on the back side of the target material. The cooling cavity is communicated with a water inlet and a water outlet, and the cooling cavity is used for circulating cooling water to cool the target material.

[0007] Preferably, the second columnar magnet is arranged perpendicular to the target surface of the target material, and the first columnar magnet gradually extends from the end far away from the target material to the end close to the central axis of the first circumference.

[0008] Preferably, it further includes a target seat connection fixing sleeve and a magnetic rail seat. The magnetic rail seat is arranged on the back surface of the target. The front surface of the magnetic rail seat is attached to the back surface of the target. The target seat connection fixing sleeve is arranged on the back surface of the magnetic rail seat and is connected to each other. A groove extending from the back surface towards the front surface is arranged on the back surface of the magnetic rail seat. The first columnar magnet is arranged inside the magnetic rail seat and is sequentially arranged around the groove. The target seat connection fixing sleeve seals the groove and forms the cooling cavity. The target seat connection fixing sleeve is electrically connected to the magnetic rail seat. The target seat connection fixing sleeve is used to connect to the negative pole of an external power supply. The second columnar magnet is arranged inside the cooling cavity. A shaft hole is arranged in the middle of the target seat connection fixing sleeve. The rotating shaft of the rotation driving device passes through the shaft hole. The free end of the rotating shaft is fixedly connected to the second columnar magnet. The axis of the rotating shaft is coaxial with the central axis of the first circumference.

[0009] Preferably, it further includes a rear backing plate. The rear backing plate is annular. The rear backing plate is arranged on the back surface of the magnetic rail seat. A plurality of accommodating cavities are arranged on the back surface of the magnetic rail seat. The plurality of accommodating cavities are sequentially arranged around the groove. One end of the first columnar magnet extends into the accommodating cavity and the other end is connected to the rear backing plate.

[0010] Preferably, it further includes an annular mounting flange. The mounting flange is arranged on the back surface of the target seat connection fixing sleeve. An insulating pad is clamped between the target seat connection fixing sleeve and the mounting flange. The rotating shaft passes through the mounting flange, the target seat connection fixing sleeve and the rear backing plate.

[0011] Preferably, it further includes a shielding cover. The front side end of the shielding cover is open, and the back side end is configured with an annular extension plate. The magnetic rail seat, the rear backing plate and the target seat connection fixing sleeve are all located inside the shielding cover. The extension plate is coaxially arranged with the mounting flange, the first circumference and the target seat connection fixing sleeve. The extension plate is located between the mounting flange and the insulating pad. The mounting flange, the extension plate, the insulating pad and the target seat connection fixing sleeve are all fixedly connected by the same set of mounting bolts. During installation, the screw rods of the mounting bolts sequentially pass through the through holes in the mounting flange, the extension plate and the insulating pad and are then threadedly connected to the threaded holes on the back surface of the target seat connection fixing sleeve. An insulating sleeve is sleeved outside the mounting bolts.

[0012] Preferably, the target is tightly fixed to the front surface of the magnetic rail seat by an annular pressing cover. The pressing cover is detachably connected to the magnetic rail seat. The pressing cover presses on the outer edge of the front surface of the target.

[0013] Preferably, the gland is installed on the front of the magnetic rail base through gland installation bolts, and the magnetic rail base is installed on the front of the target base connection fixing sleeve through magnetic rail base installation bolts.

[0014] The present invention also provides a magnetron sputtering coating device, including the center magnetic field rotatable target cathode as described above.

[0015] The present invention has achieved the following technical effects compared with the prior art: In the center magnetic field rotatable target cathode provided by the present invention, the second column magnet can be driven by a rotation driving device to rotate around the central axis of the first circumference. During the rotation of the second column magnet, due to the different distances between the second column magnet and different first column magnets, different ranges of magnetic fields can be generated, and thus the areas of the target surface sputtering runways formed are also different, thereby achieving the purpose of increasing the area of the target surface sputtering runway, improving the utilization rate of the target material and the sputtering rate. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a cross-sectional view of the center magnetic field rotatable target cathode provided by the present invention in the first direction; Figure 2 It is a cross-sectional view of the center magnetic field rotatable target cathode provided by the present invention in the second direction; Figure 3 It is a structural schematic diagram of the center magnetic field rotatable target cathode provided by the present invention at the electrical connection threaded hole; Figure 4 It is a structural schematic diagram of the water inlet pipe, water outlet pipe and diversion pipe of the center magnetic field rotatable target cathode provided by the present invention; Figure 5 It is a layout diagram of the first column magnet and the second column magnet; Figure 6 It is a target magnetic field analysis diagram; In the figure: 1 - mounting bolt; 2 - insulating sleeve; 3 - mounting flange; 4 - first vacuum sealing O-ring; 5 - second vacuum sealing O-ring; 6 - shielding cover; 7 - insulating pad; 8 - target seat connecting and fixing sleeve; 81 - water inlet pipe; 82 - water outlet pipe; 83 - diversion pipe; 84 - electric connection threaded hole; 9 - rear packing iron; 10 - first column magnet; 11 - first cooling water pressure sealing O-ring; 12 - magnetic rail seat; 121 - cooling cavity; 13 - magnetic rail seat mounting bolt; 14 - target; 15 - gland; 16 - gland mounting bolt; 17 - second column magnet; 18 - positioning pin; 19 - central rotating seat; 20 - rotating shaft; 21 - first bearing; 22 - second cooling water pressure sealing O-ring; 23 - second bearing; 24 - circlip; 25 - adapter shaft; 26 - rotating motor; 27 - motor seat; 28 - first bolt; 29 - second bolt. Detailed implementation manner

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0020] In this specification, the front and the front side of each component are viewed from the perspective of charged particles. Specifically, the side of the component facing the charged particles is the front or the front side, and the other side is the back or the back side.

[0021] Next, in conjunction with Figures 1 to 6 , the embodiments of the present invention will be described.

[0022] The present invention provides a target cathode with a rotatable central magnetic field, including: a target 14, a first column magnet 10, a second column magnet 17 and a rotation driving device. The front of the target 14 is used to collide with charged particles for sputtering; a plurality of first column magnets 10 are provided, and the plurality of first column magnets 10 are sequentially arranged along a first circumference on the back side of the target 14. The first circumference is coaxial with the target 14, and the magnetic poles of all the first column magnets 10 on the side close to the target 14 are the same; one second column magnet 17 is provided, and the second column magnet 17 is arranged on the back side of the target 14; the second column magnet 17 is eccentrically arranged within the first circumference, and the magnetic pole of the second column magnet 17 on the side close to the target 14 is opposite to the magnetic pole of the first column magnet 10 on the side close to the target 14; the rotation driving device is used to drive the second column magnet 17 to rotate around the central axis of the first circumference.

[0023] In the center magnetic field rotatable target cathode provided by the embodiment of the present invention, the second column magnet 17 can be driven by a rotation driving device to rotate around the central axis of the first circumference. During the rotation of the second column magnet 17, due to the different distances between the second column magnet 17 and different first column magnets 10, magnetic fields with different ranges can be generated, and thus the regions of the target surface sputtering tracks formed are also different, thereby achieving the purpose of increasing the region of the target surface sputtering tracks and improving the utilization rate of the target 14.

[0024] In some embodiments, a cooling cavity 121 is constructed on the back side of the target 14. The cooling cavity 121 is communicated with a water inlet channel and a water outlet channel. Cooling water is used to circulate in the cooling cavity 121 to cool the target 14.

[0025] This embodiment can reduce the probability of damage to the target 14 due to high temperature and improve the stability of sputtering.

[0026] In some embodiments, the second column magnet 17 is arranged perpendicular to the target surface of the target 14, and the first column magnet 10 extends gradually in the direction approaching the central axis of the first circumference from one end far away from the target 14 to the other end.

[0027] In this embodiment, the first column magnet 10 is inclined towards the second column magnet 17, thereby optimizing the magnetic field distribution and improving the sputtering efficiency. In a more preferred embodiment, the inclination angle of the first column magnet 10 is 30 degrees, that is, the included angle between the axis of the first column magnet 10 and the axis of the second column magnet 17 is 30 degrees.

[0028] In some embodiments, the second column magnet 17 can be an elliptical column magnet or a cylindrical magnet. The purpose of setting it as an elliptical column magnet is to utilize the special shape of the elliptical magnet and the very high uniformity magnetic field on the surface. Its magnetic field strength and direction can be adjusted according to the major and minor axes of the ellipse and the polarization direction, which is used to control the movement trajectory of charged particles and can ensure that unnecessary offsets do not occur during the acceleration process of charged particles, thereby improving the acceleration efficiency and accuracy.

[0029] In some embodiments, the embodiments of the present invention further include a target seat connection fixing sleeve 8 and a magnetic rail seat 12. The magnetic rail seat 12 is disposed on the back surface of the target 14, and the front surface of the magnetic rail seat 12 is attached to the back surface of the target 14. The target seat connection fixing sleeve 8 is disposed on the back surface of the magnetic rail seat 12 and is connected to each other. A groove extending from the back surface toward the front surface is provided on the back surface of the magnetic rail seat 12. The first columnar magnet 10 is disposed inside the magnetic rail seat 12 and is sequentially arranged around the groove. The target seat connection fixing sleeve 8 seals the groove and forms a cooling cavity 121. The target seat connection fixing sleeve 8 is electrically connected to the magnetic rail seat 12. The target seat connection fixing sleeve 8 is used to connect to the negative pole of an external power supply. The second columnar magnet 17 is disposed in the cooling cavity 121. A shaft hole is provided in the middle of the target seat connection fixing sleeve 8. The rotating shaft 20 of the rotation driving device passes through the shaft hole. The free end of the rotating shaft 20 is fixedly connected to the second columnar magnet 17. The axis of the rotating shaft 20 is coaxial with the central axis of the first circumference.

[0030] This embodiment achieves the purpose of forming a cooling cavity 121 on the back surface of the target 14. In addition, during use, a negative voltage needs to be applied to the target 14. In the embodiments of the present invention, a voltage is applied to the target seat connection fixing sleeve 8 and transmitted to the target 14 through the magnetic rail seat 12. Specifically, a power connection threaded hole 84 is provided at the back end of the target seat connection fixing sleeve 8. The power connection threaded hole 84 is used to install the nose of the connecting wire.

[0031] In some examples, the water inlet channel and the water outlet channel are provided on the target seat connection fixing sleeve 8, that is, two channels are provided on the target seat connection fixing sleeve 8, which are used as the water inlet channel and the water outlet channel respectively. In order to better inlet and outlet water, a stainless steel pipe is welded to the port of the water inlet channel on the back surface of the target seat connection fixing sleeve 8 as the water inlet pipe 81, and a stainless steel pipe is welded to the port of the water outlet channel on the back surface of the target seat connection fixing sleeve 8 as the water outlet pipe 82. A stainless steel pipe is welded to the other port of the water outlet channel as the diversion pipe 83. The gap distance between the end face of the water outlet of the diversion pipe 83 and the back surface of the magnetic rail seat 12 is preferably 1 mm. In the use state, the cooling cavity 121 is set horizontally, that is, the target 14 is set horizontally. Cooling water enters the cooling cavity 121 from the water inlet pipe 81, then enters the water outlet pipe 82 from the diversion pipe 83 and flows out, so that the cooling water completely fills the cooling cavity 121, achieving the purpose of improving the cooling effect.

[0032] In some examples, as Figure 1 shown, the rotating shaft 20 is rotatably connected to the shaft hole through the first bearing 21 and the second bearing 23, and the axial movement of the second bearing 23 is restricted by the snap ring 24. A second cooling water pressure sealing O-ring 22 is provided between the outer wall of the rotating shaft 20 and the shaft hole to prevent the cooling cavity 121 from leaking water. The setting of the bearings makes the rotating shaft 20 concentric with the magnetic rail seat 12, and makes the rotating shaft 20 not swing and rotate stably, achieving the purpose of making the central magnetic field on the target surface rotate stably without excessive changes.

[0033] In some examples, a transfer shaft 25 is further included. The rotation driving device is a rotation motor 26. The transfer shaft 25 is directly connected to the rotation motor 26, and the transfer shaft 25 is coaxially connected to the rotation shaft 20. To prevent the rotation shaft 20 from conducting electricity to the rotation motor 26, the transfer shaft 25 can be set as an insulating shaft for insulation purposes.

[0034] In some embodiments, the second column magnet 17 is installed on the central rotating seat 19 inside the cooling cavity 121 and sealed with waterproof glue. The central rotating seat 19 and the rotation shaft 20 are fixedly connected by a positioning pin 18. The waterproof glue sealing is to prevent the second column magnet 17 from rusting and corroding when soaked in cooling water for a long time.

[0035] In some examples, a deep groove for fixing the second column magnet 17 is provided on the front surface of the central rotating seat 19, so that the second column magnet 17 is not easily dropped and can work stably.

[0036] In some embodiments, the present invention embodiment further includes a rear shim 9. The rear shim 9 is annular. The rear shim 9 is arranged on the back surface of the magnetic rail seat 12. A plurality of accommodating cavities are arranged on the back surface of the magnetic rail seat 12, and the plurality of accommodating cavities are arranged in sequence around the groove. One end of the first column magnet 10 extends into the accommodating cavity, and the other end is connected to the rear shim 9.

[0037] In this embodiment, the rear shim 9 converts the magnetic quantity of all the first column magnets 10 into a magnetic ring, thereby optimizing the magnetic field distribution, so that an annular shape can be formed on the front surface of the target 14.

[0038] In some embodiments, first cooling water pressure sealing O-rings 11 are provided between the rear shim 9 and the magnetic rail seat 12, and between the rear shim 9 and the target seat connection fixing sleeve 8.

[0039] In some examples, the rear shim 9 and the central rotating seat 19 are made of Q235 material with good magnetic conductivity and have a thickness of 5 mm.

[0040] In some embodiments, the present invention embodiment further includes an annular mounting flange 3. The mounting flange 3 is arranged on the back surface of the target seat connection fixing sleeve 8. An insulating pad 7 is clamped between the target seat connection fixing sleeve 8 and the mounting flange 3. The rotation shaft 20 passes through the mounting flange 3, the target seat connection fixing sleeve 8, and the rear shim 9.

[0041] This embodiment facilitates the connection of the cathode target to the coating equipment through the mounting flange 3. It can be understood that a plurality of through holes or threaded holes are provided on the mounting flange 3 for passing bolts.

[0042] In some embodiments, the embodiment of the present invention further includes a shielding cover 6. The front side end of the shielding cover 6 is open, and a circular extension plate is configured at the back side end. The magnetic rail base 12, the rear backing iron 9, and the target seat connection fixing sleeve 8 are all located inside the shielding cover 6. The extension plate is coaxially arranged with the mounting flange 3, the first circumference, and the target seat connection fixing sleeve 8. The extension plate is located between the mounting flange 3 and the insulating pad 7. The mounting flange 3, the extension plate, the insulating pad 7, and the target seat connection fixing sleeve 8 are all fixedly connected by the same set of mounting bolts 1. During installation, the screw rods of the mounting bolts 1 sequentially pass through the through holes in the mounting flange 3, the extension plate, and the insulating pad 7 and are then threadedly connected to the threaded holes on the back of the target seat connection fixing sleeve 8. An insulating sleeve 2 is sleeved outside the mounting bolt 1. The use of the insulating sleeve 2 and the insulating pad 7 can prevent experimenters from touching the mounting bolt 1 or being electrocuted by the mounting flange 3 when the target is working, achieving the purpose of protecting the safety of experimenters.

[0043] The shielding cover 6 in this embodiment is used to connect to the ground, can shield the radiation and heat of high-energy particles generated by the experiment, reduce the radiation dose received by the operators and the surrounding environment, ensure the safety of the experiment. At the same time, the shielding cover 6 can also intercept the recoil substances and debris, prevent damage to the equipment and experimenters, achieving the purpose of ensuring the safety of the experiment, protecting the experimenters, equipment and environmental safety.

[0044] Preferably, since the turning point distance of the cycloid trajectory of secondary electrons is generally not greater than 3 mm, the gap between the shielding cover 6 and the side of the magnetic rail base 12 is set to not greater than 2.5 mm, which can make the shielding cover 6 and the magnetic rail base 12 in an open circuit state, achieving the purpose of saving energy and reducing energy consumption.

[0045] Specifically, in the magnetron sputtering coating technology, for a planar cathode, the movement trajectory of secondary electrons (the distance of electrons moving to the turning point) is a very crucial factor. When electrons are emitted from the cathode target, under the combined action of the electric field and magnetic field, they will move along a complex path. This path can be described by a cycloid, which is a mathematical curve representing the movement trajectory of electrons in the magnetic field and electric field. This distance has a decisive influence on the electron movement path in the magnetron sputtering process and can be determined by a specific formula. The formula can refer to the prior art and will not be elaborated here.

[0046] The insulating pad 7 is made of insulating materials such as polytetrafluoroethylene, with a thickness of 5 - 10 mm. The insulating pad 7 is provided with a sealing groove and circularly evenly distributed mounting holes for the insulating sleeve 2 and the mounting bolts 1 to pass through. There is a gap between the mounting holes of the insulating pad 7 and the insulating sleeve 2 to facilitate the installation of the insulating sleeve 2.

[0047] In some embodiments, the embodiments of the present invention further include a first vacuum-sealed O-ring 4 and a second vacuum-sealed O-ring 5. A second vacuum-sealed O-ring 5 is provided between the mounting flange 3 and the extension plate, and a first vacuum-sealed O-ring 4 is provided on the surface of the mounting flange 3 in contact with the coating equipment.

[0048] In some embodiments, the magnetic rail base 12 is made of red copper material with good electrical conductivity. The distance between the bottom of the cooling cavity 121 and the front surface of the magnetic rail base 12 is 2 millimeters, that is, the thickness of the part of the magnetic rail base 12 corresponding to the cooling cavity 121 is 2 millimeters.

[0049] In some embodiments, the target 14 is pressed and fixed to the front surface of the magnetic rail base 12 by an annular gland 15. The gland 15 is detachably connected to the magnetic rail base 12, and the gland 15 is pressed against the outer edge of the front surface of the target 14. Specifically, the gland 15 is installed on the front surface of the magnetic rail base 12 through gland mounting bolts 16, and the magnetic rail base 12 is installed on the front surface of the target seat connection fixing sleeve 8 through magnetic rail base mounting bolts 13.

[0050] This embodiment uses bolts to install the components, abandoning the existing gluing, which improves the working stability and service life.

[0051] According to the different thicknesses of the target 14, glands 15 of different sizes are selected for fixed installation, so that the gap between the target surface and the magnet surface of the second column magnet 17 is 2 millimeters, improving the coating quality.

[0052] In some embodiments, the rotating motor 26 is connected to the flange through the motor seat 27. The rotating motor 26 is connected to the motor seat 27 through the first bolt 28, and the motor seat 27 and the flange are connected through the second bolt 29.

[0053] The present invention also provides a magnetron sputtering coating device, including the above-mentioned center magnetic field rotatable target cathode.

[0054] This embodiment specifically has all the advantages of the above embodiments, and will not be elaborated here.

[0055] In the present invention, specific examples are used to elaborate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A target cathode with a central magnetic field that can rotate, characterized in that: include: A target material, the front side of which is used for collision with charged particles to perform sputtering; A plurality of first column magnets are provided, and the plurality of first column magnets are sequentially arranged on the back side of the target along a first circumference, the first circumference and the target are coaxial, and the magnetic poles of all the first column magnets on a side close to the target are the same; A second column magnet is provided, wherein the second column magnet is provided on the back side of the target; the second column magnet is eccentrically provided within the first circumference, and the magnetic pole of the second column magnet close to the target is opposite to the magnetic pole of the first column magnet close to the target; as well as The rotation driving device is used to drive the second column magnet to rotate around the central axis of the first circle.

2. The central magnetic field rotatable target cathode according to claim 1, characterized in that: A cooling cavity is constructed on the back side of the target material. The cooling cavity is connected with a water inlet and a water outlet. The cooling cavity is used for circulating cooling water to cool the target material.

3. The central magnetic field rotatable target cathode according to claim 1, characterized in that: The second column magnet is arranged perpendicular to the target surface of the target material, and the first column magnet gradually extends from one end away from the target material to the other end toward the direction close to the central axis of the first circle.

4. The central magnetic field rotatable target cathode according to claim 2, characterized in that: The target base connecting and fixing sleeve also includes a target base connecting and fixing sleeve and a magnetic rail seat, wherein the magnetic rail seat is arranged on the back side of the target material, the front side of the magnetic rail seat is arranged in contact with the back side of the target material, the target base connecting and fixing sleeve is arranged on the back side of the magnetic rail seat and connected to each other, the back side of the magnetic rail seat is provided with a groove extending from the back side to the front side, the first column magnet is arranged inside the magnetic rail seat and arranged in sequence around the groove, the target base connecting and fixing sleeve seals the groove and forms the cooling cavity, the target base connecting and fixing sleeve is electrically connected to the magnetic rail seat, the target base connecting and fixing sleeve is used to connect to the negative pole of an external power supply, the second column magnet is arranged in the cooling cavity, the middle part of the target base connecting and fixing sleeve is provided with an axial hole, the rotating shaft of the rotating drive device is passed through the axial hole, the free end of the rotating shaft is fixedly connected to the second column magnet, and the axis of the rotating shaft is coaxial with the central axis of the first circle.

5. The central magnetic field rotatable target cathode according to claim 4, characterized in that: It also includes a rear washer, which is annular and arranged on the back of the magnetic track seat. The back of the magnetic track seat is provided with a plurality of accommodating cavities, which are arranged in sequence around the groove. One end of the first column magnet extends into the accommodating cavity, and the other end is connected to the rear washer.

6. The central magnetic field rotatable target cathode according to claim 5, characterized in that: It also includes an annular mounting flange, which is arranged on the back side of the target base connecting and fixing sleeve, an insulating gasket is sandwiched between the target base connecting and fixing sleeve and the mounting flange, and the rotating shaft is passed through the mounting flange, the target base connecting and fixing sleeve and the rear washer.

7. The central magnetic field rotatable target cathode according to claim 6, characterized in that: It also includes a shielding cover, the front side end of the shielding cover is open, and the back side end is constructed with an annular extension plate, the magnetic rail seat, the rear washer and the target seat connecting and fixing sleeve are all located in the shielding cover, the extension plate and the mounting flange, the first circumference and the target seat connecting and fixing sleeve are all coaxially arranged, the extension plate is located between the mounting flange and the insulating pad, the mounting flange, the extension plate, the insulating pad and the target seat connecting and fixing sleeve are all fixedly connected by the same set of mounting bolts, during installation, the screw rod of each mounting bolt passes through the through holes on the mounting flange, the extension plate and the insulating pad in turn, and is then threadedly connected to the threaded hole on the back side of the target seat connecting and fixing sleeve, and the outer cover of the mounting bolt is provided with an insulating sleeve.

8. The central magnetic field rotatable target cathode according to claim 7, characterized in that: The target material is pressed and fixed on the front side of the magnetic rail seat by an annular pressure cover, the pressure cover is detachably connected to the magnetic rail seat, and the pressure cover is pressed on the outer edge of the front side of the target material.

9. The central magnetic field rotatable target cathode according to claim 8, characterized in that: The pressure cover is installed on the front side of the magnetic rail seat through pressure cover installation bolts, and the magnetic rail seat is installed on the front side of the target seat connection fixing sleeve through magnetic rail seat installation bolts.

10. A magnetron sputtering coating device, characterized in that: It comprises the target cathode with central magnetic field rotation as described in any one of claims 1 to 9.

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