Bias voltage adsorption ceramic cold roller with high thermal conductivity and high insulation and preparation method of bias voltage adsorption ceramic cold roller

Abstract

The invention discloses a bias adsorption ceramic cold roller with high thermal conductivity and high insulation and a preparation method thereof.The bias adsorption ceramic cold roller comprises a cold roller body and a composite ceramic layer arranged on the surface of the cold roller body, the composite ceramic layer comprises a high-thermal-conductivity low-insulation layer and a high-insulation low-thermal-conductivity layer, and the high-thermal-conductivity low-insulation layer comprises, by weight, 90% of silicon carbide and 10% of aluminum oxide; the high-insulation low-thermal-conductivity outer layer comprises 95% by weight of aluminum oxide and 5% by weight of silicon carbide, and in the total thickness of the composite ceramic layer, the high-insulation low-thermal-conductivity layer accounts for 40%, and the high-insulation low-thermal-conductivity layer accounts for 60%. The high-thermal-conductivity and low-insulation layer can quickly conduct heat generated by the adsorption surface to an internal cooling flow channel, the high-insulation and low-thermal-conductivity layer provides extremely high surface resistance and effectively resists electrostatic breakdown, meanwhile, the thermal expansion coefficient of the inner layer is better matched with that of the metal roller body due to the high silicon carbide content of the inner layer, and thermal stress is reduced. The ultimate insulation performance is ensured due to the high aluminum oxide content of the outer layer, and the two layers are in gradient transition through components and are firmly combined.

Description

Technical Field

[0001] This invention relates to the field of vacuum coating equipment, and in particular to a bias-adsorption ceramic cold roller with high thermal conductivity and high insulation, and its preparation method. Background Technology

[0002] In precision manufacturing, processes such as semiconductor wafer fabrication, flat panel display glass substrate fabrication, and composite current collector fabrication often employ vacuum coating, which typically utilizes electrostatic adsorption cold rollers to fix the workpiece. These cold rollers require highly efficient cooling capabilities to remove process heat, while their surfaces must possess excellent insulation to prevent electrostatic discharge damage to the equipment. Existing ceramic cold rollers often face the following contradictions: single ceramic materials struggle to simultaneously achieve high thermal conductivity and high insulation; uneven mixing or improper structural design of composite ceramic materials can easily lead to localized overheating or insulation failure. Furthermore, the cooling efficiency within the roller body directly affects the stability of the adsorption force. Therefore, there is an urgent need for a layered composite ceramic cold roller that can synergistically optimize thermal conductivity, insulation, and cooling performance. Summary of the Invention

[0003] The purpose of this invention is to provide a bias-adsorption ceramic cold roller and its preparation method, which is mainly used in vacuum coating equipment. Through its unique layered composite ceramic structure and precise material ratio, it solves the technical problem of balancing thermal conductivity and insulation performance.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A bias-adsorption ceramic cold roller with high thermal conductivity and high insulation includes a cold roller body and a composite ceramic layer disposed on the surface of the cold roller body. The composite ceramic layer includes a high thermal conductivity and low insulation layer and a high insulation and low thermal conductivity layer, with the high insulation and low thermal conductivity layer sintered outside the high thermal conductivity inner layer.

[0005] Further technology of the present invention: Preferably, the main body of the cold roller is made of aluminum alloy or stainless steel.

[0006] Preferably, a NiCrAlY transition layer is further provided between the composite ceramic layer and the cold roller body.

[0007] Preferably, the total thickness of the composite ceramic layer is 100µm to 500µm.

[0008] Preferably, in the total thickness of the composite ceramic layer, the high thermal conductivity and low insulation layer accounts for 40%, and the high insulation and low thermal conductivity layer accounts for 60%.

[0009] This invention also provides a method for preparing a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation, comprising the following steps: Step 1: Select the main body of the cold roller and perform pretreatment; Step 2: Spray a high thermal conductivity, low insulation inner layer onto the pretreated surface of the cold roll body; Step 3: Continue to spray a high-insulation, low-thermal-conductivity outer layer over the high-thermal-conductivity, low-insulation layer; Step four: The ceramic cold roller is sintered as a whole under a protective atmosphere.

[0010] Further technology: The high thermal conductivity and low insulation inner layer uses silicon carbide as the continuous phase and adds aluminum oxide as the dispersed phase, with a weight ratio of silicon carbide to aluminum oxide of 90:10.

[0011] Further technology: The high-insulation, low-thermal-conductivity outer layer uses aluminum oxide as the continuous phase and adds silicon carbide as the reinforcing phase, with the weight ratio of aluminum oxide to silicon carbide being 95:5.

[0012] Further technical steps: Step one specifically involves: First, mechanical grinding is used to remove the surface oxide scale, and then ultrasonic cleaning is performed with acetone and anhydrous ethanol in a volume ratio of 1:1 for ≥20 minutes. After cleaning, place in a vacuum baking oven with a vacuum degree ≤1×10-3Pa and keep at 180-200℃ for 40 minutes; Sandblasting with 60-mesh white corundum at a pressure of 0.7-0.9 MPa, a distance of 120-150 mm, and an angle of 50°-60° will achieve a roller surface roughness of Ra6-9 μm. Then, annular microgrooves with a depth of 0.05-0.1 mm and a spacing of 0.5 mm are processed on the roller surface by laser micro-engraving.

[0013] Further technology: Before spraying the high thermal conductivity and low insulation inner layer, a NiCrAlY transition layer with a thickness of 50-80μm is sprayed onto the surface of the cold roll body.

[0014] Further technical steps: After the high-insulation, low-thermal-conductivity outer layer is sprayed, the cold roller is placed in a CNC vacuum slow cooling furnace with a vacuum degree of ≤5×10-3Pa and cooled to room temperature at a rate of ≤5℃ / h. After slow cooling, the surface is polished sequentially with diamond grinding wheels of 800 mesh → 1200 mesh → 2000 mesh to reduce the surface roughness of the roller to below 1.5μm.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes optimized material ratios and a layered structure. The high thermal conductivity and low insulation layer can rapidly conduct heat generated on the adsorption surface to the internal cooling channels, while the high insulation and low thermal conductivity layer provides extremely high surface resistance, effectively resisting electrostatic breakdown. At the same time, the high silicon carbide content of the inner layer makes its coefficient of thermal expansion more compatible with the metal roller body, reducing thermal stress. The high alumina content of the outer layer ensures ultimate insulation performance, and the two layers are firmly bonded through a compositional gradient transition. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation provided by the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] like Figure 1 The present invention provides a bias adsorption ceramic cold roller with high thermal conductivity and high insulation, comprising a cold roller body 1 and a composite ceramic layer disposed on the surface of the cold roller body; The composite ceramic layer includes a high thermal conductivity and low insulation layer 3 and a high insulation and low thermal conductivity layer 4, with the high insulation and low thermal conductivity layer sintered outside the high thermal conductivity inner layer.

[0020] The main body of the cold roller is made of aluminum alloy or stainless steel.

[0021] A NiCrAlY transition layer 2 is also provided between the composite ceramic layer and the cold roller body.

[0022] The high thermal conductivity, low insulation layer has a weight ratio of 90% silicon carbide and 10% aluminum oxide. The high insulation, low thermal conductivity layer has a weight ratio of 95% aluminum oxide and 5% silicon carbide.

[0023] 1. Pretreatment: 1) Select a 304 stainless steel cold roller, 800mm in diameter and 800mm in length. First, use mechanical grinding to remove the surface oxide scale, then use acetone and anhydrous ethanol (volume ratio 1:1) for ultrasonic cleaning (30min) to remove oil and dust; after cleaning, place it in a vacuum baking oven (vacuum degree ≤1×10). -3(Pa), keep warm at 180-200℃ for 40 minutes.

[0024] 2) Surface roughening treatment: First, sandblast with white corundum (60 mesh) at a pressure of 0.8 MPa, a distance of 130 mm, and an angle of 55° to make the surface roughness of the roller reach Ra6-9 μm; then, annular microgrooves with a depth of 0.08 mm and a spacing of 0.5 mm are processed on the roller surface by laser micro-engraving.

[0025] 3) Pre-coating: A low-pressure explosive spraying mode is adopted, and a NiCrAlY transition layer with a thickness increased by 60μm is pre-coated. The fuel gas (acetylene) pressure is 0.07MPa, the combustion accelerant (oxygen) pressure is 0.25MPa, the powder feeding rate is 18g / min, and the coating is allowed to cool naturally to 90℃ after spraying before the main coating is applied.

[0026] 2. Main coating explosion spraying stage: 1) Equipment debugging and test spraying: Select JP-9000 type explosion spraying equipment, check the sealing of fuel gas, combustion aid and powder feeding system; load silicon carbide and alumina composite ceramic powder (particle size 50-80μm, drying temperature 120℃, time 30min) into powder feeder, and perform test spraying with test blocks of the same material as the cooling roller to verify that the coating thickness and microstructure meet the standards before formal operation.

[0027] 2) Main coating spraying operation: The cooling roller is fixed on a CNC rotary worktable, and the spraying method of "reciprocating superposition + zone speed control" is adopted: 3) Spraying parameter settings: distance between spray gun and roller surface 230mm, fuel gas (acetylene) pressure 0.11MPa, combustion aid (oxygen) pressure 0.35MPa, oxygen to acetylene volume ratio 3:1 (to ensure complete combustion and improve powder melting rate). 4) Motion parameter settings: worktable speed 45r / min, spray gun axial movement speed 6mm / s, pause for 1.5min after every 2 layers (to release internal stress), spray 120um of high thermal conductivity and low insulation layer, spray a total of 4 layers to complete, spray 180um of high insulation and low thermal conductivity layer, spray a total of 6 layers to complete.

[0028] 3. Post-processing stage: After the coating is completed, the cooling roller is placed in a CNC vacuum slow cooling furnace (vacuum degree ≤ 5×10). -3 The coating is cooled to room temperature at a rate of ≤5℃ / h to avoid cracking due to excessive temperature difference. After slow cooling, it is polished sequentially with diamond grinding wheels of 800 mesh → 1200 mesh → 2000 mesh to reduce the surface roughness of the roller to below 1.5um, which ensures heat transfer efficiency and avoids surface protrusions from affecting bias adsorption.

[0029] Example 2 (60µm high thermal conductivity, low insulation layer + 240µm high insulation, low thermal conductivity layer): The high thermal conductivity, low insulation layer has a weight ratio of 90% silicon carbide and 10% aluminum oxide. The high insulation, low thermal conductivity layer has a weight ratio of 95% aluminum oxide and 5% silicon carbide.

[0030] Except for the main coating explosion spraying stage 4) in Example 1, in which the high thermal conductivity and low insulation layer is sprayed at 60µm and a total of 2 layers are sprayed, and the high insulation and low thermal conductivity layer is sprayed at 240µm and a total of 8 layers are sprayed, the remaining steps are the same.

[0031] Example 3 (High thermal conductivity, low insulation layer 240µm + High insulation, low thermal conductivity layer 60µm): The high thermal conductivity, low insulation layer has a weight ratio of 90% silicon carbide and 10% aluminum oxide. The high insulation, low thermal conductivity layer has a weight ratio of 95% aluminum oxide and 5% silicon carbide.

[0032] Except for the main coating explosion spraying stage 4) in Example 1, in which the high thermal conductivity and low insulation layer is sprayed at 240µm and a total of 8 layers are sprayed, and the high insulation and low thermal conductivity layer at 60µm is sprayed at 2 layers, the remaining steps are the same. Comparative Example 1 (pure Al2O3 coating 300µm): Except for the main coating explosion spraying stage 4) motion parameters in Example 1, a total of 10 layers were sprayed to complete the process. The remaining steps are the same.

[0033] Detection and analysis: The cold rolls obtained in Examples 1 to 3 and the cold roll obtained in Comparative Example 1 were subjected to performance tests. The specific test items and results are recorded in Table 1 below: Table 1 lists the test items related to the cold roll. Table 2 shows the test results for the cold roll. Combining the advantages of both silicon carbide and Al2O3, the following summary is provided: Because silicon carbide has a higher hardness than Al2O3, the coating in Example 3 has the highest hardness.

[0034] High thermal conductivity and low insulation layer (such as silicon carbide) are generally more dense than insulation layer. The higher the proportion of it, the smoother the coating surface. Therefore, Example 3 has the lowest roughness and Example 2 has the highest roughness. The pure aluminum oxide coating of Comparative Example 1 has a roughness higher than that of Examples 1 and 3 because the spraying process easily produces a small number of pores and particles.

[0035] The thicker, high thermal conductivity, low insulation layer in the composite coating has better compatibility with the thermal expansion coefficient of 304 stainless steel, which can reduce thermal stress. Therefore, the bonding strength of Example 3 is better than that of Examples 1 and 2. In Comparative Example 1, pure aluminum oxide has a dense structure and strong physical bonding with the substrate, and its bonding strength is slightly higher than that of Example 3.

[0036] The thermal conductivity is dominated by the high thermal conductivity and low insulation layer, following Fourier's law of thermal conduction. The thicker the layer, the lower the thermal resistance. Therefore, Example 3 has the best thermal conductivity, while Example 2 has the best. Comparative Example 1 has the lowest thermal conductivity due to the low thermal conductivity of pure aluminum oxide.

[0037] The insulation performance is determined by the insulation layer. The thicker the insulation layer, the longer the charge conduction path and the higher the resistivity. Therefore, Example 2 has the highest resistivity, while Example 3 and 3 have the lowest resistivity because the insulation layer is the thinnest. Comparative Example 1, pure aluminum oxide, has excellent insulation properties and its resistivity is close to that of Example 1.

[0038] The insulation performance is determined by the insulation layer. The thicker the insulation layer, the longer the charge conduction path and the higher the resistivity. Therefore, Example 2 has the highest resistivity, while Example 3 has the lowest resistivity because the insulation layer is the thinnest. Comparative Example 1, pure aluminum oxide, has excellent insulation properties and its resistivity is close to that of Example 2 but slightly lower.

[0039] The composite coating with a thick, high thermal conductivity, and low insulation layer is more likely to form uniform particle deposition under bias voltage. Example 3 has the best uniformity. In Example 2, the particle deposition is easily hindered due to the excessively thick insulation layer, resulting in the worst uniformity. In Comparative Example 1, the pure aluminum oxide coating has a single composition, and the particle movement is stable under bias voltage, with uniformity close to that of Example 1.

[0040] In summary: Considering the requirements of "high heat dissipation + good adsorption effect under low voltage", Implementation Example 1 is the optimal choice based on its advantages in heat dissipation, hardness, and low-pressure adsorption effect.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation, characterized in that, Includes a cold roll body and a composite ceramic layer disposed on the surface of the cold roll body; The composite ceramic layer includes a high thermal conductivity and low insulation layer and a high insulation and low thermal conductivity layer, with the high insulation and low thermal conductivity layer sintered outside the high thermal conductivity inner layer.

2. The bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 1, characterized in that, A NiCrAlY transition layer is also provided between the composite ceramic layer and the cold roller body.

3. The bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 1, characterized in that, The total thickness of the composite ceramic layer is 100um~500um.

4. The bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 3, characterized in that, Of the total thickness of the composite ceramic layer, the high thermal conductivity and low insulation layer accounts for 40%, and the high insulation and low thermal conductivity layer accounts for 60%.

5. A method for preparing a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Select the main body of the cold roller and perform pretreatment; Step 2: Spray a high thermal conductivity, low insulation inner layer onto the pretreated surface of the cold roll body; Step 3: Continue to spray a high-insulation, low-thermal-conductivity outer layer over the high-thermal-conductivity, low-insulation layer; Step four: The ceramic cold roller is sintered as a whole under a protective atmosphere.

6. The method for preparing a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 5, characterized in that, The high thermal conductivity and low insulation inner layer uses silicon carbide as the main continuous phase and adds aluminum oxide as the dispersed phase, with a weight ratio of silicon carbide to aluminum oxide of 90:

10.

7. The method for preparing a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 5, characterized in that, The high-insulation, low-thermal-conductivity outer layer uses aluminum oxide as the continuous phase and adds silicon carbide as the reinforcing phase, with a weight ratio of aluminum oxide to silicon carbide of 95:

5.

8. The method for preparing a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 5, characterized in that, Step one is as follows: First, mechanical grinding is used to remove the surface oxide scale, and then ultrasonic cleaning is performed with acetone and anhydrous ethanol in a volume ratio of 1:1 for ≥20 minutes. After cleaning, place in a vacuum baking oven with a vacuum degree ≤1×10-3Pa and keep at 180-200℃ for 40 minutes; Sandblasting with 60-mesh white corundum at a pressure of 0.7-0.9 MPa, a distance of 120-150 mm, and an angle of 50°-60° will achieve a roller surface roughness of Ra6-9 μm. Then, annular microgrooves with a depth of 0.05-0.1 mm and a spacing of 0.5 mm are processed on the roller surface by laser micro-engraving.

9. The method for preparing a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 8, characterized in that, Before spraying the high thermal conductivity and low insulation inner layer, a NiCrAlY transition layer with a thickness of 50-80μm is sprayed onto the surface of the cold roll body.

10. The method for preparing a bias-adsorption ceramic cooling roller with high thermal conductivity and high insulation according to claim 5, characterized in that, After the high-insulation, low-thermal-conductivity outer layer is coated, the cold roller is placed under a vacuum of ≤5×10⁻⁶. -3 Pa's numerically controlled vacuum slow cooling furnace cools the temperature to room temperature at a rate of ≤5℃ / h; After slow cooling, the surface is polished sequentially with diamond grinding wheels of 800 mesh → 1200 mesh → 2000 mesh to reduce the surface roughness of the roller to below 1.5μm.

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