Method capable of realizing double-sided simultaneous coating on surface of wide base material

Abstract

The invention discloses a method capable of realizing double-sided simultaneous coating on the surface of a wide base material, and particularly relates to the technical field of metal material plating, the method comprises the following steps: carrying out ultrasonic cleaning pretreatment on the wide base material, placing the wide base material in a vacuum cavity, carrying out bias cleaning, then carrying out ion source cleaning, removing a surface oxide layer, and forming a microscopic rough structure. And then, by adopting an inner-outer double-circle target material layout and a closed magnetic field design, the plasma density is increased to more than 5mA / cm, and the wide base material stably revolves in a middle region of the two sputtering targets, so that a coating with a single-layer, mixed-layer or multi-layer superlattice structure is simultaneously deposited on two surfaces. According to the method, the density and binding force of the film layer can be improved by synchronously applying ion beams to assist deposition, and the target sputtering power proportion is adjusted to prepare a gradient coating or a composite coating. The method effectively solves the problems of difficulty in double-sided film coating of a large workpiece, low target material utilization rate and poor film layer quality, improves the comprehensive performance of the film layer, reduces the production cost and improves the production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material plating, and more specifically, to a method capable of realizing double-sided simultaneous film coating on a wide substrate surface. Background Art

[0002] In the field of metal material plating technology, with the continuous development of new industries, special and stringent requirements are put forward for the surface performance of materials. Double-sided coating of large workpieces has become a key challenge faced by the industry. Traditional coating technology has many difficult to overcome problems when processing large-sized workpieces.

[0003] On the one hand, it is very difficult to achieve double-sided coating on large workpieces. Existing equipment and processes cannot ensure uniform and efficient deposition of film layers on both sides of wide substrates, resulting in low production efficiency and inability to meet large-scale production needs.

[0004] On the other hand, the low utilization rate of target materials has long been a problem that has plagued the industry. A large number of target materials have not been fully utilized during the coating process, resulting in a waste of resources and a significant increase in production costs. At the same time, the film quality is poor, and the performance indicators such as the density, bonding strength and uniformity of the film layer are difficult to reach the ideal state, which cannot meet the requirements of new industries for high performance of material surfaces.

[0005] Therefore, a method for realizing double-sided simultaneous coating on a wide substrate surface is now proposed. Summary of the invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for realizing simultaneous double-sided coating on the surface of a wide substrate, aiming to solve the problems that have long plagued the development of the industry, such as the difficulty of double-sided coating of large workpieces, low utilization rate of target materials and poor quality of film layers, thereby effectively meeting the special and stringent requirements of new industries for material surface properties. Through the technical solution of the present invention, the comprehensive performance of the film layer can be significantly improved, the production cost can be reduced, and the production efficiency can be greatly improved, providing strong support for the technological progress and sustainable development of related industries.

[0007] To achieve the above object, the present invention provides the following technical solution: a method for realizing double-sided simultaneous coating on a wide substrate surface, comprising the following steps: (1) After ultrasonic cleaning pretreatment, the wide substrate is placed in a vacuum chamber; (2) After bias cleaning the wide substrate for 5-10 minutes, ion source cleaning is performed for 5-10 minutes to remove the oxide layer on the substrate surface and form a microscopic rough structure; (3) depositing a coating on both sides of the substrate simultaneously, wherein the coating is a single layer, a mixed layer or a multi-layer superlattice structure, and the film thickness is 20-30 nm; Among them, in step (3), an inner and outer double-circle target layout is adopted, and the magnetic fields of the inner and outer targets are coupled by a closed magnetic field design, so that the plasma density is increased to above 5mA / cm², and then the wide substrate is smoothly revolved in the middle area of ​​the two sputtering targets, and the atoms sputtered by the target are received on both sides at the same time. The target sputtered atoms are evenly deposited on both sides of the substrate, and double-sided coating is performed.

[0008] Preferably, the closed magnetic field design includes: the magnetic field strength of the outer circle target is higher than that of the inner circle target, and the magnetic poles of adjacent targets are in opposite directions, forming magnetic field coupling; part of the magnetic lines of force extend to the surface of the substrate, allowing secondary electrons to escape and collide with neutral particles to ionize, thereby increasing the plasma concentration.

[0009] Preferably, the power supply configuration for bias cleaning and ion source cleaning includes: 1 30kW bias power supply and 2 6kW ion source power supplies, the ion beam energy is 800-1000eV, and the ion beam current density is 2-5mA / cm².

[0010] Preferably, the target material is selected from one or more of W, Ni, Ta, Ti, Cr, and Pt, and the type and position of the target material are dynamically adjusted according to the film layer requirements.

[0011] Preferably, the preparation of the multilayer superlattice structure comprises: forming an ultra-thin composite film with 5 to 20 alternating layers by alternately sputtering different target materials and controlling the deposition time to be 1 to 5 minutes per layer.

[0012] Preferably, the substrate is a metal plate with a width of ≥800 mm.

[0013] Preferably, ion beam assisted deposition is applied synchronously during the coating process, and ion bombardment is enhanced by a negative bias voltage of 700-1000V to improve the density and bonding strength of the film layer.

[0014] Preferably, the method further comprises the preparation of a gradient coating or a composite coating: by adjusting the target material sputtering power ratio to achieve a composition gradient change or co-deposition of multiple elements.

[0015] Beneficial effects of the present invention: By adopting a closed magnetic field design, the plasma density is increased, and the substrate ion current density is increased to more than 5mA / cm², which enhances the bombardment effect on the surface of the deposited film and improves the film quality. The film thickness can be accurately controlled within the range of 20-30nm to prepare multi-layer ultra-thin superlattice structure films. By synchronously applying ion beam assisted deposition, 700-1000V negative bias is used to enhance the ion bombardment effect and improve the density and bonding strength of the film. Gradient coatings or composite coatings can also be prepared by adjusting the target sputtering power ratio to achieve composition gradient changes or co-deposition of multiple elements to meet the diverse performance requirements of the film in different fields.

[0016] The equipment has stable bias cleaning and ion source cleaning functions, combined with local magnetic field closure technology, which improves target material utilization, reduces target material waste, and thus reduces production costs.

[0017] By adopting an inner and outer double-circle target layout and a unique workpiece revolution method, it is possible to achieve simultaneous coating on both sides of a wide substrate. Compared with the traditional single-sided coating method, the coating time is greatly shortened and production efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of the method of the present invention for realizing double-sided simultaneous coating on a wide substrate surface; Figure 2 Schematic diagram of the film structure of method 1 in embodiment 2 of the present invention; Figure 3 Schematic diagram of the film structure of method 2 in embodiment 2 of the present invention; Figure 4 Schematic diagram of the membrane layer structure of method 3 in embodiment 2 of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, the present invention provides a method for realizing double-sided simultaneous coating on a wide substrate surface, comprising the following steps: After the substrate is pre-treated by ultrasonic cleaning, it is placed in the equipment cavity. After bias cleaning the wide substrate for 5-10 minutes, it is cleaned by ion source for 5-10 minutes to remove the oxide layer on the surface of the substrate and form a microscopic rough structure on the surface of the substrate to appropriately increase the adhesion between the coating and the substrate; Uniform coatings are prepared on both sides of the substrate. The coatings can be mixed on the substrate or stacked layer by layer.

[0021] Target configuration and target position arrangement: The equipment innovatively sets up inner and outer target areas, and the target types of the inner and outer rings are extremely rich, covering W, Ni, Ta, Ti, Cr, Pt and other element targets that play a decisive role in the performance of the film layer. In the actual application process, technicians can accurately select the appropriate target material according to the specific performance requirements of different film layers. Whether it is the use of a single element target or a combination of multiple element targets, it can be easily achieved.

[0022] High-performance power control system: It integrates two core functions: stable bias cleaning and ion source cleaning, providing a solid and reliable guarantee for the coating process.

[0023] Under the action of bias voltage, the oxide layer and impurities on the surface of the substrate are ionized and decomposed, and then pumped out of the cavity by the vacuum pump to achieve the cleaning of the substrate surface. At the same time, the application of bias voltage can also activate the atoms on the surface of the substrate and enhance the activity of the substrate surface. According to the material, surface condition and specific requirements of the film layer of the substrate, the size and action time of the bias voltage can be flexibly adjusted to create favorable conditions for the subsequent formation of a strong bond between the film layer and the substrate.

[0024] The ion source power supply ensures that the ion source can generate high-energy, high-density ion beams, which, under the acceleration of the electric field, hit the substrate surface at high speed to further clean the substrate. It can not only remove the tiny impurity particles remaining on the substrate surface, but also further activate the atoms on the substrate surface to make them more active. When preparing multiple layers of ultra-thin fine film layers, a stable and efficient cleaning process is particularly critical. Because the ultra-thin film layer has extremely high requirements for the cleanliness and activity of the substrate surface, any tiny impurities or surface defects may have a serious impact on the quality and uniformity of the film layer. Through the stable operation of the high-performance power control system, the consistency of the substrate surface state before each coating can be ensured, thereby effectively improving the quality and uniformity of the film layer and ensuring the stability of product quality.

[0025] Magnetic field design: In order to achieve the simultaneous coating on both sides of the wide substrate surface, a special magnetic field design is carried out by adopting unbalanced magnetron sputtering technology, and the plasma on the cathode target surface is led to the range of 200-300mm in front of the sputtering target, so that the substrate is immersed in the plasma, which overcomes the shortcomings of balanced magnetron sputtering. In this process, the sputtered atoms and particles are deposited on the substrate surface to form a thin film, and the plasma bombards the substrate with a certain energy, playing the role of ion beam assisted deposition. The film quality is improved, and it has the functions of ion cleaning, activation of the workpiece surface and film modification. The design with the outer ring magnetic field strength higher than the core magnetic field strength is selected, and its magnetic lines of force do not completely form a closed loop, and part of the outer ring magnetic lines of force extend to the substrate surface. This structure allows some secondary electrons to escape from the target surface area along the magnetic lines of force and collide with neutral particles for ionization, so that the plasma is no longer completely confined to the target surface area, but can reach the substrate surface, further increasing the ion concentration in the coating area and increasing the substrate ion current density, which can usually reach more than 5mA / cm². In this case, the sputtering source also acts as an ion source to bombard the substrate surface, and the substrate ion beam density is proportional to the target current density. The increase in the target current density can not only increase the deposition rate, but also enhance the substrate ion beam density, thereby having a certain bombardment effect on the surface of the deposited film layer.

[0026] Coating process Simultaneous double-sided coating: By optimizing the equipment structure and process parameters, and adopting a unique workpiece revolution method and target layout, during the coating process, wide and large parts can smoothly revolve in the middle area of ​​the two sputtering targets, while receiving atoms sputtered from the target on both sides, thus achieving efficient and uniform double-sided coating.

[0027] The specific process parameters are: 100 sccm, 0.3 Pa of Ar was introduced, a negative bias of 700 V was applied, and a DC power supply with an output power of 7 kW and a medium frequency power supply with an output power of 14 kW were used to clean the target and substrate.

[0028] The bias voltage and the output of the DC power supply were changed to prepare a titanium base layer with a coating time of 30 minutes.

[0029] The bias voltage of each sputtering target and the output of the DC power supply are changed to prepare the corresponding film layer. At this time, the rotation speed of the workpiece in the chamber is 10-30r / min. A multi-layer film structure is prepared.

[0030] Precise control of the growth of multiple film layers: Multiple elements are evenly mixed on the surface of the substrate to form an alloy film layer with specific properties. For example, when preparing a wear-resistant film layer for automobile engine parts, the automobile engine parts can be: pistons (rings), cylinder walls, valves (seats), camshafts, tappets, rocker arms, connecting rods, etc., and targets such as Cr, Mo, and W can be sputtered at the same time, and their sputtering ratios and times can be precisely controlled. A Cr-Mo-W alloy film layer can be formed on the surface of the substrate, which has excellent wear resistance and corrosion resistance, and can effectively improve the service life and performance of automobile engine parts. In addition, if different target materials are sputtered in a certain order, a film layer with a multi-layer structure is formed. Through this overlapping film layer structure design, the functional advantages of each layer can be brought into play at different levels, the comprehensive performance of the film layer can be significantly improved, and the diversified needs of the film layer in different fields can be met.

[0031] Embodiment 1 By adjusting the ratio of elements such as Ti, Cr, and N and the preparation process of the film, the performance of the TiCrN film can be optimized to better meet various application requirements. It can provide good wear resistance, corrosion resistance, and oxidation resistance for parts in the automotive industry and aerospace, improve the reliability and service life of parts, and ensure the safe operation of equipment.

[0032] The TiCrN film is prepared by large-scale magnetron sputtering (PVD) coating equipment to improve the quality and performance of the TiCrN film. The specific steps include: 1. Select a titanium plate with a size of 820 mm to be coated, first put it into acetone solution for ultrasonic cleaning for 15 minutes to remove oil and impurities on the surface of the substrate. Then rinse it with deionized water, put it into anhydrous ethanol for ultrasonic cleaning for 10 minutes, and finally blow it dry with nitrogen.

[0033] 2. Clamp the cleaned substrate on the workpiece rack of the large magnetron sputtering (PVD) coating equipment to ensure that the substrate can revolve smoothly between the two target circles.

[0034] 3. Seal the cavity of the large magnetron sputtering (PVD) coating equipment, start the vacuum pump, and draw the vacuum degree in the cavity to 5×10 -3 Pa.

[0035] 4. Turn on the bias power supply, apply a negative bias of 700V on the substrate, introduce argon gas to maintain the gas pressure in the chamber at 0.8Pa, and perform bias cleaning for 10 minutes to remove the oxide layer and residual impurities on the surface of the substrate and activate the substrate surface.

[0036] 5. Start the ion source and adjust the parameters of the ion source so that the ion beam energy is 950eV and the ion beam current density is 3mA / cm². Clean the substrate with the ion source for 5 minutes to further improve the cleanliness and activity of the substrate surface.

[0037] 6. Turn off the argon gas and introduce a mixture of nitrogen and argon with a flow ratio of 5:1 to maintain the gas pressure in the chamber at 0.6Pa.

[0038] 7. Turn on the power of the titanium target and the chromium target, and adjust the sputtering power of the target. The sputtering power of the titanium target is 10kW, and the sputtering power of the chromium target is 15kW. At the same time, turn on the bias power supply and apply a bias of 700V on the substrate to enhance the bombardment of ions on the film layer and improve the density and bonding strength of the film layer.

[0039] 8. Start the revolution system of the workpiece holder, so that the substrate revolves at a speed of 2r / min between the two target circles to ensure that the film layer is evenly deposited on the surface of the substrate.

[0040] 9. Control the deposition time according to the desired thickness of the TiCrN film. Generally speaking, a deposition time of 60 minutes can produce a TiCrN film with a thickness of 2 μm.

[0041] Embodiment 2: Some key moving parts in marine equipment (such as bearings, plungers and cylinders) have been subjected to long-term wear and corrosion by seawater, organisms and other corrosive substances. Under the combined effects of force, chemistry and electrochemistry, the performance of these metal parts is greatly reduced, the wear of parts is aggravated, and eventually premature failure occurs, seriously affecting the service stability and service life of the equipment. In order to enhance the tribological properties of CrC in air, water and other environments, and to solve defects such as microcracks that occur during the deposition of the film layer, a method that can achieve double-sided simultaneous coating on a wide substrate surface was used to prepare three structures of the film layer. Specifically, the following steps are included: 1. Substrate treatment: The titanium plate is ultrasonically cleaned to remove oil, dust and impurities, and then placed in the vacuum chamber of the coating equipment after drying.

[0042] 2. Pump the vacuum chamber pressure to 3×10 −3 Pa. Argon gas is introduced for gas washing to further remove residual impurity gases.

[0043] 3. Adjust the argon pressure in the vacuum chamber to 1.0 Pa, apply a pulse bias of 700 V to the sample stage for 30 minutes, and use the generated plasma to etch and clean the substrate surface to improve the bonding strength between the coating and the substrate.

[0044] 4. Perform bias cleaning on the Cr target and C target respectively, adjust the vacuum chamber pressure to 2Pa, the current is generally 2A, clean for 35 minutes, and remove the oxide layer and contaminants on the target surface.

[0045] 5. Introduce argon gas and control the gas pressure of the vacuum chamber to 0.2 Pa. Turn on the sputtering power supply, and change the power of the Cr medium frequency power supply and the C direct current power supply of the Cr target and the C target. In the CrC layer, the power of the Cr medium frequency power supply changes from 12kW to 5kW at a rate of 0.00729kW / s; the power of the C direct current power supply changes from 2kW to 8kW at a rate of 0.00625kW / s to achieve different film layer structures.

[0046] As attached Figure 2 As shown, method 1 is used for the precipitation process of the multi-layer alternating structure. By quickly switching the target material and accurately controlling the deposition time, the process is repeated 10 times to achieve the alternating deposition of Cr and C. The deposition process parameters of method 1 are shown in Table 1.

[0047] Table 1: Method 1 precipitation process parameters As attached Figure 3As shown, method 2 is used for the gradient change process of the gradient layer structure, by gradually adjusting the power of the Cr target and the C target, wherein the power of the Cr medium frequency power supply in the CrC layer is changed from 12kW to 5kW at a rate of 0.00729kW / s; the power of the C DC power supply is changed from 2kW to 8kW at a rate of 0.00625kW / s, to achieve a gradient change in composition. The gradient change process parameters of method 2 are shown in Table 2.

[0048] Table 2: Gradient change process parameters of method 2 As attached Figure 4 As shown, for the composite coating process of the composite layer structure, method 3 is adopted, the Cr target and the C target are turned on at the same time, and the power ratio is adjusted to form a Cr-C composite coating. The composite coating process parameters of method 3 are shown in Table 3 below.

[0049] Table 3: Process parameters of composite coating of method 3 6. Since the magnetic fields of the inner and outer targets are coupled, and the magnetic fields of the adjacent targets are also coupled, in this closed magnetic field environment, the argon gas is ionized to form plasma. The electrons in the plasma make spiral motion under the action of the magnetic field and are confined near the target material, increasing the probability of collision with the argon gas, thereby generating more argon ions. Under the bombardment of argon ions, Cr atoms and C atoms are sputtered from the surface of the target material, and under the combined action of the electric field and the magnetic field, they move to the surface of the titanium plate substrate at a certain angle and speed and deposit.

[0050] 7. The titanium plate revolves between two targets at a speed of 15N / min in the chamber. During the revolution, the substrate surface evenly receives atoms sputtered from the Cr target and the C target. The sputtering lasts for 16 minutes to achieve the designed CrC film thickness and composition ratio.

[0051] Finally, a few points should be explained: First, in the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change; Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other; Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for achieving simultaneous double-sided coating on a wide substrate surface, characterized in that: The following steps are involved: (1) After ultrasonic cleaning pretreatment, the wide substrate is placed in a vacuum chamber; (2) After bias cleaning the wide substrate for 5-10 minutes, ion source cleaning is performed for 5-10 minutes to remove the oxide layer on the substrate surface and form a microscopic rough structure; (3) depositing a coating on both sides of the substrate simultaneously, wherein the coating is a single layer, a mixed layer or a multi-layer superlattice structure, and the film thickness is 20-30 nm; Among them, in step (3), an inner and outer double-circle target layout is adopted, and the magnetic fields of the inner and outer targets are coupled by a closed magnetic field design, so that the plasma density is increased to above 5mA / cm², and then the wide substrate is smoothly revolved in the middle area of ​​the two sputtering targets, and the atoms sputtered by the target are received on both sides at the same time. The target sputtered atoms are evenly deposited on both sides of the substrate, and double-sided coating is performed.

2. A method for realizing double-sided simultaneous coating on a wide substrate surface according to claim 1, characterized in that: The closed magnetic field design includes: the magnetic field strength of the outer circle target is higher than that of the inner circle target, and the magnetic poles of adjacent targets are in opposite directions, forming magnetic field coupling; part of the magnetic lines of force extend to the surface of the substrate, allowing secondary electrons to escape and collide with neutral particles for ionization, thereby increasing the plasma concentration.

3. A method for realizing double-sided simultaneous coating on a wide substrate surface according to claim 1, characterized in that: The power supply configuration for the bias cleaning and ion source cleaning includes: one 30kW bias power supply and two 6kW ion source power supplies, the ion beam energy is 800-1000eV, and the ion beam current density is 2-5mA / cm².

4. A method for realizing double-sided simultaneous coating on a wide substrate surface according to claim 1, characterized in that: The target material is selected from one or more of W, Ni, Ta, Ti, Cr, and Pt, and the type and position of the target material are dynamically adjusted according to the film layer requirements.

5. The method for realizing double-sided simultaneous coating on a wide substrate surface according to claim 1, characterized in that: The preparation of the multilayer superlattice structure includes: forming an ultra-thin composite film with 5 to 20 alternating layers by alternately sputtering different target materials and controlling the deposition time to be 1 to 5 minutes per layer.

6. The method for realizing double-sided simultaneous coating on a wide substrate surface according to claim 1, characterized in that: The substrate is a metal plate with a width of ≥800 mm.

7. The method for realizing double-sided simultaneous coating on a wide substrate surface according to claim 1, characterized in that: During the coating process, ion beam assisted deposition is applied synchronously, and the ion bombardment effect is enhanced by a negative bias voltage of 700-1000V to improve the density and bonding strength of the film layer.

8. The method for realizing double-sided simultaneous coating on a wide substrate surface according to claim 1, characterized in that: The method also includes the preparation of a gradient coating or a composite coating: by adjusting the target material sputtering power ratio, a gradient change in composition or co-deposition of multiple elements can be achieved.

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