WO2013010509A1

WO2013010509A1 - Reduced droplet arc target and plasma coating system with same

Info

Publication number: WO2013010509A1
Application number: PCT/CN2012/078986
Authority: WO
Inventors: 董小虹; 张中弦; 梁航; 黄拿灿; 哥罗沃依•亚历山大
Original assignee: 广东世创金属科技有限公司
Priority date: 2011-07-21
Filing date: 2012-07-21
Publication date: 2013-01-24
Also published as: CN102260850A

Abstract

The present invention relates to a reduced droplet arc target and a plasma coating system with same. The system includes a reduced droplet arc target, a vacuum chamber, a vacuum pump set, a working turnplate, an industrial gas and a bias power source. The cathode target of the reduced droplet arc target and a water cooling seat are provided inside the internal cavity of the vacuum chamber. A large electromagnetic coil of the reduced droplet arc target, a programmable direct current power source, an arc current source and a cooling water pipe extending from the water inlet of the water cooling seat are provided outside the vacuum chamber, and an electromagnetic element of the reduced droplet arc target is provided inside the internal cavity of or outside the vacuum chamber.The present invention can change the radius of the arch magnetic field generated by the magnet by way of periodical coil current change and presents periodical change, thus increasing the movement speed of arc spots on the surface of the cathode target, significantly decreasing the generation of arc ion coated large droplets, and ensuring the surface of the cathode target is etched evenly and making full use of the target material.At the same time, the invention has the advantages of simple and rational structure, convenient installation and adjustment, and good cooling effects.

Description

Plasma spraying system with less droplet arc target and arc droplet target with less droplets

The present invention relates to a low droplet arc target and a plasma coating system with a low droplet arc target. It belongs to the field of vacuum arc ion plating technology.

Background technique

Arc ion plating technology, because of the simple structure of the device, the cathode target is both the evaporation source of the cathode material and the ion source; the ionization rate is high (generally up to 60%~80%), the deposition rate is high; the incident ion energy is large, With high film/base bonding strength and good coating quality, it has a wide application range and strong practicability. As a hard film coating method, it has been widely used in tools and various tooling. However, in the prior art arc ion plating system, there are large particles (micropart icles) contamination in the coating, which makes the surface of the coating rough, the porosity increases, and the coating performance is unstable, which restricts to some extent. Arc ion plating hard coatings for precision tooling and high-end parts.

Ion plating technology, when depositing, when the surface of the cathode target is ignited by an external circuit to generate an arc, the temperature of the ignition target of the cathode target is increased, a large amount of electrons are emitted into the space, and a certain proportion of the metal atoms of the target are evaporated. The inelastic collision of the hot electrons with these metal atoms ionizes them into positive ions, and the positive ions accumulate in front of the arc spots to form an ion cloud, because the ion cloud is close to the surface of the cathode (about 10 microns), and the ion cloud is at the cathode. The potential is high and a strong electric field is formed on the surface of the cathode. This electric field has a strong drag effect on electrons inside the metal surface, producing strong field electron emission, generating a stable high current density, high energy density electron flow. The high energy density electron flow causes the cathode arc spot to locally heat up rapidly and form a micro-melting pool, which generates a large amount of metal material entrapped in the droplets. The metal vapor stream is in front of the cathode and is inelastically collided by the high-speed electron flow, and the metal vapor is ionized again. It is a high-energy positive ion, which in turn enhances the field emission effect. Such a thermal field emission mechanism is repeated to maintain the arc target discharge, and a high ionization rate, high energy cathode target material plasma stream is emitted at the cathode target. In general, the field emission electron flow is first broken at a portion where the cathode surface is protruded or where the work function is low, and an arc spot is formed. A burn pit is formed in the arc spot due to vaporization of the cathode material, so that the conditional change of the field-emitting electrons disappears, and a second field emission arc is formed at another position. The arc spot is not fixed and it migrates rapidly on the surface of the cathode. The morphology of ion-coated particles has been carefully observed by many researchers. It is generally believed that the particles are molten materials of the cathode target, formed by droplets ejected from the micro-melting pool of the cathode arc spot, are spherical in space, and become flat when solidified on the surface of the substrate, and are often goose-like or spherical particles. They vary in size from a few micrometers to a few dozen micrometers, and individual tens of micrometers. Since the particles are produced by the melting of the cathode target, it is necessarily related to the temperature of the melting, and the higher the melting temperature, the larger the particles produced. The arc spot after the arcing of the conventional cathode target generally exhibits an irregular free motion, and the moving speed is slow, which causes the arc spot to stay at a certain point on the surface of the cathode target for a long time, and the target surface is melted at that point. The temperature is higher, so the more the particles are.

The arc evaporation source in the prior art has the disadvantages of large metal particles, poor quality of deposited film layers, low utilization of targets, complicated structure, troublesome installation adjustment, and poor cooling effect. Summary of the invention

The first object of the present invention is to solve the problem that the vacuum arc ion plating apparatus in the prior art has large metal particles obtained by evaporation, poor quality of the deposited film layer, low utilization rate of the target material, complicated structure, and troublesome installation adjustment. The disadvantage of poor cooling effect is to provide a low-drop arc target, which can significantly reduce the generation of large droplets of arc ion plating, and uniformly ablate the surface of the cathode target, thereby effectively improving the utilization efficiency of the target.

A second object of the present invention is to provide a plasma coating system with a small droplet arc target, which has the advantages of simple and reasonable structure, convenient installation and adjustment, and good cooling effect.

The first object of the present invention can be achieved by adopting the following technical solutions:

A droplet-free arc target characterized by: comprising a cathode target, a water-cooled seat on a back surface of the cathode target, and a cooling water pipe extending from a water inlet of the water-cooling seat, in a cavity of the water-cooled seat or a surface of the cooling water pipe a permanent magnet electromagnetic element is arranged, a large electromagnetic coil is arranged on the back side of the permanent magnet electromagnetic element, a programmable DC power supply is connected to the large electromagnetic coil; an arc current source is connected to the cooling water pipe; and the large electromagnetic coil is sleeved on the cooling water pipe; The polarity of the magnetic field generated by the large electromagnetic coil is opposite to the polarity of the permanent magnet electromagnetic element, and a superimposed magnetic field generated by both the permanent magnet electromagnetic element and the large electromagnetic coil is formed on the surface of the cathode target, the superimposed magnetic field strength accompanying the large electromagnetic coil As the current cycle changes, the radius of motion of the cathodic arc spot of the cathode target changes periodically.

A first object of the present invention can also be attained by the following technical solution: A technical improvement to achieve the first object of the present invention is: forming a superposition of both the permanent magnet electromagnetic element and the large electromagnetic coil on the surface of the cathode target The magnetic field, the superimposed magnetic field is an arched bending magnetic field B, which is formed by superposing two components of a parallel magnetic field B 1 and a vertical magnetic field B2 with respect to the cathode target surface, gp : B = B 1 + B 2 .

A technical improvement to achieve the first object of the present invention is: The permanent magnet electromagnetic element is composed of a permanent magnet or a small electromagnetic coil.

The second object of the present invention can be achieved by adopting the following technical solutions:

A plasma coating system with a small droplet arc target, which is characterized by:

1) consisting of a small droplet arc target, a vacuum chamber, a vacuum pump set, a work turntable, a process gas, and a bias power supply;

2) The cathode target and the water-cooled seat of the small-drop arc target are located in the inner cavity of the vacuum chamber, the large electromagnetic coil of the droplet-off-arc target, the programmable DC power source, the arc current source and the water from the water-cooled seat The cooling water pipe extending from the mouth is located outside the vacuum chamber, and the permanent magnet electromagnetic component of the small droplet arc target is located in the inner cavity or the outer side of the vacuum chamber; the permanent magnet electromagnetic component is composed of a permanent magnet or a small electromagnetic coil;

3) The working turntable is disposed in the inner cavity of the vacuum chamber, and the power input end of the working turntable is connected to the output end of the bias power source; the air extracting port of the vacuum pumping group is connected to the inner cavity of the vacuum chamber, and the process gas is connected to the air inlet of the vacuum chamber.

A second object of the present invention can also be achieved by adopting the following technical solution: A technical improvement to achieve the second object of the present invention is: the water-cooled seat includes a target seat water jacket, and is connected to the inner cavity of the target seat water jacket Cooling water pipe; the target water jacket is installed in the vacuum chamber, the cooling water pipe extends outward through the side wall of the vacuum chamber, and communicates with the external cooling water, the cooling water pipe is connected with the arc current source; the cathode target is fixed at the target seat The right end of the water jacket is open; the permanent magnet is installed in the inner cavity of the water jacket of the target seat in the vacuum chamber; or the permanent magnet or the small electromagnetic coil is installed on the cooling water pipe located outside the vacuum chamber.

A technical improvement to achieve the second object of the present invention is: the inner cavity of the target seat water jacket is divided into a front water cooling chamber and a rear water cooling chamber that communicate with each other; the target seat water jacket passes through the target mounting flange and the vacuum chamber side The interface flange on the wall is sealed and fixedly connected; the cooling water pipe is composed of an inlet pipe and an outlet pipe; one end of the inlet pipe is connected with the front water cooling cavity, and the other end is connected to the external cooling water pipe through the side wall of the vacuum chamber, and one end of the outlet pipe It is connected to the rear water cooling chamber, and the other end is connected to the external cooling water pipe through the side wall of the vacuum chamber.

A technical improvement to achieve the second object of the present invention is to provide a terminal for connection to an arc current source on the inlet or outlet pipe.

A technical improvement to achieve the second object of the present invention is: a shielding cover is provided on the side of the target water jacket on the cathode target.

A technical improvement to achieve the second object of the present invention is: The magnet is mounted in the front cold water chamber of the target seat water jacket by means of a adjusting screw.

The beneficial effects of the invention:

1. The small droplet arc target according to the present invention can accelerate the movement speed of the arc spot by installing a group of magnets or small electromagnetic coils behind the cathode target, and significantly reduce the generation of large droplets of arc ion plating; Behind the electromagnetic coil, a large electromagnetic coil is installed, and a special cyclically varying direct current is added to the electromagnetic coil through a programmable direct current power source. The polarity of the magnetic field generated is opposite to the polarity of the magnet, and the current can be changed by the coil cycle. The radius of the arched magnetic field generated by the magnet changes periodically, so that the moving speed of the arc spot on the surface of the cathode target is accelerated, the generation of large droplets of arc ion plating is significantly reduced, and the surface of the cathode target is uniformly ablated, making full use of Target.

2. The target water jacket of the present invention comprises a front water cooling chamber and a rear water cooling chamber, and the inlet pipe and the outlet pipe of the target water jacket are connected to the external cooling water pipe through the side wall of the vacuum chamber; Mounted on the inlet pipe outside the vacuum chamber, the magnet or small electromagnetic coil can be installed in the rear water cooling chamber of the target seat water jacket located in the vacuum chamber as needed, or installed on the cooling water pipe located outside the vacuum chamber. Therefore, the invention has the advantages of simple and reasonable structure, convenient installation and adjustment, and good cooling effect. At the same time, the axial position of the magnet can be adjusted by adjusting the screw so that the radius of motion of the cathode arc spot is in an appropriate range. With the cathode target of the present invention, the surface thereof can be uniformly ablated, and the utilization rate is high.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of a plasma coating system with a small droplet arc target according to a first embodiment of the present invention.

Fig. 2 is a schematic view showing the structure of a small droplet arc target according to a first embodiment of the present invention. Fig. 3 is a schematic view showing the structure of a plasma coating system with a small droplet arc according to a second embodiment of the present invention.

Fig. 4 is a schematic view showing the structure of a plasma coating system with a small droplet arc according to a third embodiment of the present invention.

Fig. 5 is a schematic view showing the structure of a plasma coating system with a small droplet arc according to a fourth embodiment of the present invention.

detailed description

Specific embodiment 1 :

Referring to Figure 1, a plasma coating system with a small droplet arc target as described in this embodiment:

1) consisting of a small droplet arc target, a vacuum chamber 1, a vacuum pump group 2, a work turntable 4 for placing the workpiece 3, a process gas 15 and a bias power source 1 1;

2) The cathode target 6 of the small droplet arc target and the water-cooling seat 5 are located in the inner cavity of the vacuum chamber 1, the large electromagnetic coil 10 of the droplet arc target, the programmable DC power source 1 1, the arc current source 12 and the water-cooling seat The cooling water pipe extending from the water inlet of the 5 is located outside the vacuum chamber, and the electromagnetic component of the small droplet arc target is located in the inner cavity or the outer side of the vacuum chamber 1;

3) The working turntable 4 is disposed in the inner cavity of the vacuum chamber 1, and the power input end of the working turntable 4 is connected to the output end of the bias power supply 1 1; the exhaust opening of the vacuum pump set 2 is connected to the inner cavity of the vacuum chamber 1, and the process gas 15 is connected to the vacuum. The air inlet of chamber 1.

Referring to FIG. 2, a small droplet arc target according to the embodiment includes a cathode target 6, a water cooling seat 5 is disposed on the back surface of the cathode target 6, and a cooling water pipe is extended from the water inlet of the water cooling seat 5, The inner surface of the water cooling seat 5 or the surface of the cooling water pipe is provided with an electromagnetic element, and a large electromagnetic coil 10 is disposed on the back surface of the electromagnetic element, and the large electromagnetic coil 10 is connected with a programmable DC power source 1 1; the cooling water pipe is connected with an arc current source 1 2 ; Large electromagnetic coil 10 is sleeved in cold However, the polarity of the magnetic field generated by the large electromagnetic coil 10 and the polarity of the electromagnetic element must be opposite, and a superimposed magnetic field generated by both the electromagnetic element and the large electromagnetic coil is formed on the surface of the cathode target 6, and the magnetic field strength is accompanied by a large electromagnetic field. The current of the coil 10 changes with a periodic change, and the radius of motion of the cathode arc spot of the cathode target 6 changes periodically. An arcing electrode 7 is provided on one side of the cathode target 6.

In this embodiment:

A superimposed magnetic field generated by both the electromagnetic element and the large electromagnetic coil 10 is formed on the surface of the cathode target 6, and the superimposed magnetic field is an arc-shaped bending magnetic field B, which is composed of a parallel magnetic field B1 and a vertical magnetic field B2 with respect to the cathode target surface. The components are superimposed, :B=B1 + B2. The electromagnetic element is composed of a permanent magnet 8.

The water cooling seat 5 includes a target water jacket 5-1, a cooling water pipe 5-2 communicating with the inner cavity of the target water jacket 5-1, and a target water jacket 5-1 installed in the vacuum chamber 1, the cooling water pipe 5 -2 extends outward through the side wall of the vacuum chamber 1 and communicates with an external cooling water port, the cooling water pipe 5-2 is connected to the arc current source 12; the cathode target 6 is fixed to the right end opening of the target water jacket 5-1 The magnet 8 is mounted in the inner cavity of the target holder water jacket 5-1 located in the vacuum chamber 1.

The inner cavity of the target water jacket 5-1 is divided into a front water cooling chamber 5-1-1 and a rear water cooling chamber 5-1-2 which are in communication with each other; the target water jacket 5-1 passes through the target mounting flange 5-3 Sealed and fixedly connected to the interface flange on the side wall of the vacuum chamber 1; the cooling water pipe 5-2 is composed of the inlet pipe 5-2-1 and the outlet pipe 5-2-2; one end of the inlet pipe 5-2-1 is cooled with the front water The cavity 5-1-1 is connected, and the other end thereof is connected to the external cooling water pipe through the side wall of the vacuum chamber 1. The one end of the outlet pipe 5-2-2 is connected to the rear water cooling chamber 5-1-2, and the other end thereof passes through. The side wall of the vacuum chamber 1 is connected to an external cooling water pipe.

A terminal 13 connected to the arc current source 12 is provided on the outlet pipe 5-2-2.

A shield cover 5-4 is provided on the side of the target water jacket 5-1 on the cathode target 6. It is possible to limit the movement of the arc spot on the surface of the cathode target to the side.

The magnet 8 is mounted in the rear cold water chamber 5-1-2 of the target holder water jacket 5-1 by an adjusting screw 5-5. For the parallel magnetic field Bl generated by the magnet, the axial position of the magnet can be adjusted by adjusting the screw so that the radius of motion of the cathode arc spot is in an appropriate range.

The working principle of the invention:

1. During operation, the cooling water directly reaches the front water cooling chamber from the inlet pipe to cool the back surface of the cathode target, and then enters the rear water cooling chamber to cool the magnet, and then discharges through the outlet pipe. The arc power is connected to the arc power terminal, and the arc current passes. The outlet pipe, the rear water-cooling chamber casing, and the front water-cooling chamber are transferred to the cathode target, and the arc spot is ignited by the arcing electrode on the side of the cathode target.

2. In order to accelerate the moving speed of the arc spot on the cathode target surface, the present invention installs a special array of magnets behind the cathode target, and an arc-shaped bending magnetic field B is generated on the surface of the cathode target by the magnet, and the arc-shaped bending magnetic field is opposite to Parallel magnetic field B1 and perpendicular magnetic field of the cathode target surface The two components of field B2 are superimposed, gp : B = B1 + B2; under the action of the vertical magnetic field B2, the velocity of the arc spot will increase. Under the action of the horizontal magnetic field B1, the cathode arc spot is forced to move on the cathode target surface, and the radius of motion is affected by the Lorentz force F: F = Iz X B1; where Iz is the arc current, generally through the matching Arc power adjustment. For the B1 generated by the magnet, the axial position of the magnet can be adjusted to make the radius of motion of the cathode arc spot in an appropriate range. Under the action of the horizontal magnetic field B1, the radius of motion of the cathodic arc spot can only be fixed, so that the ablation of the cathode target will be uneven, which affects the utilization of the cathode target. In order to improve the utilization rate of the cathode target, the invention is provided with an electromagnetic coil behind the magnet, and a special cyclically varying DC current is added to the electromagnetic coil through the programmable DC power source, and the polarity of the magnetic field generated and the polarity of the magnet must be On the contrary, the magnetic field on the surface of the cathode target will be superimposed by the magnetic field generated by both the magnet and the electromagnetic coil. The strength of the magnetic field will also change with the current cycle of the electromagnetic coil, and the radius of motion of the cathodic arc spot will also change periodically. . Therefore, with the cathode target of the present invention, the surface thereof can be uniformly ablated, and the utilization rate is high.

Specific embodiment 2:

Referring to Fig. 3, the feature of this embodiment is that the electromagnetic element is composed of a permanent magnet 8. The permanent magnet 8 is mounted on an inlet pipe 5-2-1 located outside the vacuum chamber 1. Others are the same as in the specific embodiment 1.

Specific Example 3:

Referring to Fig. 4, the features of this embodiment are as follows: The electromagnetic element is composed of a small electromagnetic coil 9 which is mounted in the rear cold water chamber 5-1-2 of the target holder water jacket 5-1 located in the vacuum chamber 1. Others are the same as in the specific embodiment 1.

Specific Example 4:

Referring to Fig. 5, the features of this embodiment are as follows: The electromagnetic element is constituted by a small electromagnetic coil 9, and the small electromagnetic coil 9 is mounted on an inlet pipe 5-2-1 located outside the vacuum chamber 1. Others are the same as in the specific embodiment 1.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any technical person skilled in the art within the scope of the present disclosure, according to the technical solution of the present invention and Equivalent substitutions or changes of the inventive concept are within the scope of the invention.

Claims

Rights request

1. A droplet-free arc target, comprising: a cathode target (6), a water-cooling seat (5) on a back surface of the cathode target (6), and a section extending from a water inlet of the water-cooling seat (5) a cooling water pipe, a permanent magnet electromagnetic element is disposed on a surface of the water cooling seat (5) or a surface of the cooling water pipe, and a large electromagnetic coil (10) is disposed on a back surface of the permanent magnet electromagnetic element, and the large electromagnetic coil (10) is connected Programmable DC power supply (11); cooling water pipe connected with arc current source (12); large electromagnetic coil (10) socketed on cooling water pipe; large electromagnetic coil (10) generated magnetic field polarity and said permanent magnet electromagnetic element The polarity of the opposite is formed on the surface of the cathode target (6) by a superimposed magnetic field generated by both the permanent magnet electromagnetic element and the large electromagnetic coil, and the superimposed magnetic field strength varies with the current period of the large electromagnetic coil (10), and the cathode target ( 6) The radius of motion of the cathodic arc spot changes periodically.

2. A droplet-dropping arc target according to claim 1, wherein: a superimposed magnetic field generated by both the permanent magnet electromagnetic element and the large electromagnetic coil (10) is formed on the surface of the cathode target (6), and the magnetic field is superposed. The arcuate bending magnetic field B is formed by superposing two components of a parallel magnetic field B1 and a vertical magnetic field B2 with respect to the cathode target surface, BP: B = B1 + B2.

3. A low-drop arc target according to claim 1 or 2, characterized in that the permanent magnet electromagnetic element consists of a permanent magnet (8) or a small electromagnetic coil (9).

4. A plasma coating system with a low droplet arc target according to claim 1 wherein:

1) consisting of a small droplet arc target, a vacuum chamber (1), a vacuum pump set (2), a work turntable (4), a process gas (15), and a bias supply (11);

2) The cathode target (6) and the water-cooled seat (5) of the small-drop arc target are located in the inner cavity of the vacuum chamber (1), the large electromagnetic coil (10) of the droplet-off-arc target, the programmable DC power supply (11), The arc current source (12) and the cooling water pipe extending from the water inlet of the water cooling seat (5) are located outside the vacuum chamber, and the permanent magnet electromagnetic component of the small droplet arc target is located inside or outside the vacuum chamber (1); The magnet electromagnetic component is composed of a permanent magnet (8) or a small electromagnetic coil (9);

3) The working turntable (4) is set in the inner cavity of the vacuum chamber (1), and the power input end of the working turntable (4) is connected to the output end of the bias power supply (14); the air outlet of the vacuum pump set (2) is connected to the vacuum chamber ( 1) The inner chamber, process gas (15) connects the air inlet of the vacuum chamber (1).

5. The plasma coating system with a small droplet arc target according to claim 4, wherein: the water cooling seat (5) comprises a target seat water jacket (5-1), and a target seat water jacket (5-1) The cooling water pipe (5-2) connected to the inner cavity; the target water jacket (5-1) is installed in the vacuum In the chamber (1), the cooling water pipe (5-2) extends outward through the side wall of the vacuum chamber (1) and communicates with the external cooling water, cooling water pipe (5-2) and arc current source (12) Connection; the cathode target (6) is fixed at the right end opening of the target seat water jacket (5-1); the permanent magnet (8) is installed in the inner cavity of the target seat water jacket (5-1) located in the vacuum chamber (1) Medium; or a permanent magnet (8) or a small solenoid (9) mounted on a cooling water pipe (5-2) located outside the vacuum chamber (1).

6. A plasma coating system with a small droplet arc target according to claim 5, wherein: the inner cavity of the target water jacket (5-1) is partitioned into a front water cooling chamber that communicates with each other (5- 1-1) and the rear water cooling chamber (5-1-2); the interface flange of the target water jacket (5-1) through the target mounting flange (5-3) and the vacuum chamber (1) Sealed fixed connection; cooling water pipe (5-2) consists of inlet pipe (5-2-1) and outlet pipe (5-2-2); one end of inlet pipe (5_2_1) and front water cooling chamber (5-1-1) Connected, the other end is connected to the external cooling water pipe through the side wall of the vacuum chamber (1), one end of the outlet pipe (5-2-2) is connected to the rear water cooling chamber (5-1-2), and the other end is worn. The vacuum chamber (1) side wall is connected to the external cooling water pipe.

7. A plasma coating system with a small droplet arc target according to claim 6, wherein: the inlet pipe (5-2-1) or the outlet pipe (5-2-2) is provided Terminal block ( 13) connected to the arc current source ( 12).

8. A plasma coating system with a small droplet arc target according to claim 5, wherein: the target water jacket (5-1) is provided with a shield on the side of the cathode target (6) ( 5-4).

9. A plasma coating system with a low droplet arc target according to claim 6, wherein: said magnet (8) is mounted on a target water jacket by an adjusting screw (5-5).

(5-1) in the front cold water chamber (5-1-1).