Preparation method of normal-pressure plasma electrode ceramic wafer

Abstract

The invention relates to a preparation method of a normal-pressure plasma electrode ceramic wafer. The preparation method comprises the following steps: checking raw materials; performing high-temperature aging on the green ceramic chip; fixing the green ceramic chip and the chip mounting frame; punching the surface of the green ceramic chip to form a via hole, then filling the via hole with the conductive slurry, and enabling the surface of the ceramic body to be flat and smooth; the conductive slurry is conveyed to the ceramic body through silk-screen printing; carrying out cavity opening processing on the green ceramic chip by using laser; printing a circuit pattern on the surface of the green ceramic chip by using a silk-screen printing method; laminating the ceramic chips on which the printed circuit patterns are printed, and processing by an isostatic press; cutting and separating, then sintering, and electroplating the lead aperture of the normal-pressure plasma electrode plate; and welding the lead with the aperture of the lead of the normal-pressure ceramic electrode slice, inspecting the product, and packaging to obtain the normal-pressure plasma electrode slice. The method has the effect of improving the air tightness, the electrical property, the thermal conductivity, the chemical property and the high temperature resistance of the product.

Description

Technical Field

[0001] This application relates to the field of semiconductor ceramics, and in particular to a method for preparing a ceramic sheet for an atmospheric pressure plasma electrode. Background Technology

[0002] In the field of semiconductor ceramic packaging, as electronic products develop towards miniaturization, high density, and high reliability, surface mount technology (SMT) has become the mainstream technology for electronic assembly. Surface mount devices (SMDs), as the core components of SMT, have their packaging structure directly determining their performance and application scenarios. Among these, ceramic substrates prepared using high-temperature co-fired ceramic (HTCC) technology, with their excellent mechanical strength, insulation, and thermal expansion coefficient matching that of semiconductor materials, have become a key carrier for realizing high-reliability SMD power device packaging.

[0003] In an ideal SMD power device package, the circuitry should be embedded in the ceramic substrate with high quality to form a robust three-dimensional interconnect structure, ensuring the device's hermeticity, electrical stability, and long service life under harsh operating environments (such as high temperature, high frequency, and plasma environments). However, in the current HTCC manufacturing process, improper parameter control in the preceding processes such as aging, drilling, and lamination of the green ceramic sheet can directly lead to defects such as blank deformation, poor alignment accuracy, and even interlayer delamination, making it difficult to guarantee the yield and long-term reliability of the final product. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a method for preparing a ceramic sheet for an atmospheric pressure plasma electrode.

[0005] This application provides a method for preparing a ceramic sheet for an atmospheric pressure plasma electrode, which adopts the following technical solution: A method for preparing a ceramic sheet for an atmospheric pressure plasma electrode includes the following steps: S1. Raw material inspection: Inspect the raw materials, then take the materials to obtain raw ceramic pieces; S2. Aging: The raw ceramic tiles are aged by heating. S3. Frame and film application: Fix the green ceramic tile to the frame using a vacuum adsorption platform and then apply the film. Finally, apply a micro-adhesive film to the Mylar surface. S4. Drilling and filling: Drill holes on the surface of the raw ceramic sheet to form through holes, then fill the through holes with conductive paste, and then adjust the pressure to make the surface of the ceramic body smooth and flat. S5. Printing: By screen printing, a printing screen coated with conductive paste is placed on the ceramic blank, and then pressure is applied, and the conductive paste is transferred from the holes of the screen to the ceramic blank. S6. Cavity Opening: Based on the provided cavity structure, a laser is used to open a cavity on a green ceramic sheet with a printed conductor. S7. Screen Printing: Using screen printing, a circuit pattern is printed on the surface of the raw ceramic sheet through the prepared screen printing hole to obtain a ceramic sheet with a printed circuit pattern. S8. Stacking and static pressing: The ceramic sheets with printed circuit patterns are stacked in the design order. Then, the temperature and pressure are adjusted, and the stacked green ceramic sheets are placed in an isostatic press to bond the multiple green ceramic sheets together to obtain a multi-layer substrate blank. S9. Hot cutting and electroplating: The multilayer substrate blank is cut and separated according to the cutting boundaries of each component and module, and then placed in a sintering furnace for sintering. Then, the lead hole diameter of the atmospheric pressure plasma electrode sheet is electroplated. S10, Brazing: The lead wire is welded to the lead wire hole of the atmospheric pressure ceramic electrode sheet. After inspecting the product, it is packaged to obtain the atmospheric pressure plasma electrode sheet.

[0006] By adopting the above technical solution, drilling holes on the green ceramic sheet is one of the key process technologies in HTCC manufacturing. Through-holes and vias for electrical interconnection are fabricated on the thin ceramic sheet, and then conductive paste is used to fill the through-holes, achieving three-dimensional wiring and high-density interconnection. Simultaneously, a continuous conductive network is formed between the filling material and the printed circuit layer, resulting in good conductivity continuity and improving the electrical stability of the electrode sheet in the plasma environment. In step S5, pressure is applied during the printing process, causing the conductive paste to be transferred from the holes in the stencil to the ceramic blank. Furthermore, the screen printing plate is soft and requires little printing pressure. The screen is soft and elastic, with strong ink coverage and a strong three-dimensional effect. After the cavity is opened in step S6, the product can realize functions such as circuit connection and encapsulation, so as to achieve a high-precision and high-quality cavity structure and provide a foundation for subsequent assembly and encapsulation steps. In the subsequent step S8, after static pressure treatment, multiple layers of green ceramic sheets are bonded together to form a complete and dense multilayer substrate blank, and the strength is further improved. The final product has improved airtightness, electrical properties, thermal conductivity, chemical properties and high temperature resistance.

[0007] Preferably, in step S2, the aging temperature is 65-75℃ and the aging time is 18-22min. In step S4, the drilling method is either mechanical drilling or laser drilling.

[0008] By adopting the above technical solution, and optimizing the aging temperature within the specified range, the molecular motion and internal stress release of the green ceramic sheet are effectively achieved, resulting in uniform distribution of all components. Simultaneously, optimizing the aging time within the specified range ensures sufficient aging time and prevents the green ceramic sheet from becoming too brittle due to excessive aging time, which could negatively impact the quality of subsequent drilling. In step S4, the mechanical drilling speed and depth are relatively easy to control, resulting in smooth hole shapes, high laser drilling rate, and good economic benefits. A large aspect ratio can be obtained.

[0009] Preferably, the laser drilling frequency is 115KHz, the power is 71%, and the drilling speed is 410mms. After laser drilling, the hole is then repaired, and the repair is preferably performed at a frequency of 110KHz, a power of 68%, and a speed of 400mms.

[0010] By adopting the above technical solution, the frequency, power and drilling rate of laser drilling are preferably within the above range, and the resulting hole diameter is flat and the depth is moderate. After drilling, the hole is repaired, which further improves the quality of the hole.

[0011] Preferably, in step S5, the conductive paste includes terpineol, MOF metal composite material, polypyrrole, and dispersant.

[0012] By adopting the above technical solution, terpineol in the conductive paste serves as a carrier, resulting in complete and clear patterns. The printed circuit patterns can be firmly adhered to the surface of the green ceramic sheet. MOF metal composite materials are also added to the conductive paste, providing the main electron transport channels and constructing an efficient heat transfer pathway. The polypyrrole in the conductive paste itself has good conductivity and can fill the tiny gaps between MOF material particles, thereby forming an all-round conductive network and improving the compatibility between MOF materials and organic carriers. Ultimately, this synergistically enhances the conductivity of the system and further improves the overall thermal conductivity and airtightness of the system. The stable carbon layer and metal phase formed after high-temperature sintering of the MOF material have stable chemical properties and improved thermal stability.

[0013] Preferably, the raw materials for the MOF metal composite material include cobalt nitrate hexahydrate, nickel acetate tetrahydrate, glutaric acid, and melamine.

[0014] By adopting the above technical solution, nickel acetate tetrahydrate and cobalt nitrate hexahydrate provide nickel ions and cobalt ions as metal nodes of MOF structure, forming a bimetallic synergistic effect, reducing defects in subsequent heat treatment process, and effectively improving the overall electrical performance of the system. Glutaric acid, as an organic ligand, becomes the linker of MOF skeleton. Melamine is subsequently used to generate carbon nanotubes, which grow on the MOF surface, improving the mechanical strength and interfacial bonding of the system.

[0015] Preferably, the MOF metal composite material is prepared by the following method: Glutaric acid, potassium hydroxide, nickel acetate tetrahydrate, water, and ethanol were mixed, stirred, and then transferred to a reaction vessel for heating and reaction. After cooling, washing, and drying, MOF nanomaterials were obtained. MOF nanomaterials, melamine, and ethanol were mixed and dried to obtain a dried product. The dried product was then calcined at high temperature and kept at that temperature to finally obtain MOF metal composite materials.

[0016] By adopting the above technical solution, a uniform ultrathin nanoribbon MOF precursor is first prepared by glutaric acid, potassium hydroxide, nickel acetate tetrahydrate and cobalt nitrate hexahydrate. Then, carbon nanotubes are generated on the surface of the MOF nanoribbon by melamine. The prepared MOF metal composite material has a uniform composition and can be stably dispersed in the system, so that the conductive paste has good stability and conductivity, as well as good thermal stability.

[0017] Preferably, the mass ratio of nickel acetate tetrahydrate to cobalt nitrate hexahydrate is (17.2-19.2):1.

[0018] By adopting the above technical solution, and preferably within the above range the mass ratio of nickel acetate tetrahydrate to cobalt nitrate hexahydrate, with nickel as the main component and cobalt as the auxiliary component, the resulting bimetallic system can form a MOF precursor with a regular structure and few defects, reducing its high-temperature migration and sintering, and making the subsequently generated carbon nanotubes have good uniformity and consistency.

[0019] Preferably, the mass ratio of the MOF nanomaterial to melamine is 1:(8.5-9.5).

[0020] By adopting the above technical solution, the mass ratio between MOF nanomaterials and melamine is preferably within the above range, and the carbon source is sufficient, so that a continuous and uniform carbon nanotube network can be grown on the surface of the MOF precursor, thereby making the conductive pathway complete.

[0021] Preferably, the proportion of MOF metal composite material in the conductive paste is 8-12 wt%.

[0022] By adopting the above technical solution, the proportion of MOF metal composite material in the conductive slurry is preferably within the above range, so that the slurry can form a through conductive and thermally conductive network after sintering, thereby further improving the conductivity and thermal conductivity of the product. At the same time, the slurry and the ceramic green body can form a stable interface bond, further improving the product quality.

[0023] In summary, this application includes at least one of the following beneficial technical effects: 1. By integrating core HTCC processes such as hole filling, screen printing, and stacking and co-firing, three-dimensional high-density wiring inside the green ceramic sheet was achieved, which effectively improved the integration, airtightness and electrical stability of the electrode sheet in the plasma environment. 2. The optimized laser drilling parameters and MOF composite conductive paste work synergistically, with the former ensuring high-precision and high-quality interconnected cavities, and the latter improving the product's electrical performance and heat dissipation capabilities by constructing a robust conductive and thermally conductive network. 3. Precisely controlled preparation of bimetallic MOF precursors and slurry formulation form a continuous conductive and thermally conductive network, synergistically improving the product's conductivity, thermal conductivity and corrosion resistance. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the preparation process of the atmospheric pressure plasma electrode ceramic sheet in this application.

[0025] Figure 2 This is a design drawing of the aperture lead interface of the atmospheric pressure plasma electrode in this application.

[0026] Figure 3 This is a design diagram of the internal inductance circuit of the atmospheric pressure plasma electrode sheet before sintering in this application.

[0027] Figure 4 This is the design drawing of the atmospheric pressure plasma electrode ceramic before sintering in this application.

[0028] Figure 5 This is a schematic diagram of the finished atmospheric pressure plasma electrode ceramic sheet produced by sintering, electroplating, and brazing in this application. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the embodiments: Raw material description: All raw materials in the examples are commercially available; in the conductive paste, the dispersant is γ-aminopropyltriethoxysilane (CAS No.: 919-30-2), the particle size of the metallic silver conductive powder is 0.5-1.0μm, and the Mylar surface is a specific functional surface formed by casting raw ceramic sheet, which is used to adhere the micro-adhesive film to protect the circuit pattern. Example 1 Preparation of MOF metal composites: 15.61 g of glutaric acid (CAS No.: 110-94-1), 9.03 g of potassium hydroxide, 18.9 g of nickel acetate tetrahydrate (CAS No.: 6018-89-9), and 1.1 g of cobalt nitrate hexahydrate (CAS No.: 10026-22-9) were mixed into a 1:1 mixture of 400 g of ethanol and deionized water. The mixture was magnetically stirred at 25 °C until all components were fully dissolved, yielding a solution. The solution was then transferred to a polytetrafluoroethylene-lined reactor, heated to 180 °C, and reacted for 48 h. The mixture was then naturally cooled to 25°C, washed three times alternately with deionized water and ethanol, and dried in a vacuum drying oven at 60°C for 12 hours to obtain MOF nanomaterials. 7g of MOF nanomaterials and 59.5g of melamine (CAS No.: 108-78-1) were added to 500g of ethanol and stirred evenly. After the ethanol evaporated, the mixture was dried in a vacuum oven at 60°C for 6 hours to obtain a mixture. The mixture was then heated to 700°C in a tube furnace at a rate of 2°C / min and held at this temperature for 4 hours under nitrogen to obtain MOF metal composite materials.

[0030] Preparation of conductive paste: According to the mass percentage, the conductive slurry contains 1.5 wt% ethyl cellulose (CAS No.: 9004-57-3), 6 wt% pyrrole (CAS No.: 109-97-7), 8 wt% MOF metal material, 1 wt% dispersant, 60 wt% metallic silver conductive powder, and the balance is terpineol. The terpineol, dispersant and ethyl cellulose are ball-milled at 200 rpm for 30 min. Then, during the stirring process, polypyrrole, MOF metal composite material and metallic silver conductive powder are added in sequence, and the mixture is stirred at 300 rpm for 60 min to obtain the conductive slurry. Preparation of ceramic plates for atmospheric pressure plasma electrodes: S1. Raw material inspection: Inspect the raw materials, take qualified materials, and obtain untreated raw ceramic pieces; S2. Aging: The untreated raw ceramic pieces are subjected to high-temperature aging at 65°C for 22 minutes to obtain raw ceramic pieces. S3. Frame and film application: Fix the green ceramic tile and frame in position using a vacuum adsorption platform, and stick them together with tape. Then apply the film to the Mylar surface. S4. Drilling and Filling: Drilling is performed on the surface of the green ceramic sheet using laser drilling at a frequency of 115 kHz, a power of 71%, and a speed of 410 mm / s. The drilled holes are then trimmed using a frequency of 110 kHz, a power of 68%, and a speed of 400 mm / s. Conductive paste is then filled into the holes on the drilled green ceramic sheet to create vertical pathways for circuit connections between layers. Hole filling is performed using printing. The machine parameters are: pressure 550 N, squeegee position 75 mm, distance from the plate 0.13 mm, printing speed 8 mm / s, and filling speed 10 mm / s, resulting in a ceramic green body. After filling, the surface of the ceramic green body is leveled by adjusting the pressure. S5. Printing: Use screen printing. The printing station and printing machine parameters are as follows: pressure 72N, squeegee position 140mm, distance from the plate 2.0mm, printing speed 40mm / s, and inking speed 60mm / s. S6. Cavity Opening: Based on the cavity structure, a laser is used to open a cavity on a green ceramic sheet with a printed conductor. The parameters of the cavity opening machine are: frequency 100KHz, power 66%, and speed 300mm / s. S7. Screen printing: Using screen printing, the coated screen is printed to obtain a ceramic sheet with a printed circuit pattern. S8. Stacking and isostatic pressing: The ceramic sheets with printed circuit patterns are stacked in the design order to meet the requirements of the composite circuit structure, and to align and accurately position them. During the stacking process, the green ceramic sheets are rotated counterclockwise in sequence according to the flow of the green ceramic sheets. The stacked green ceramic sheets are then bonded together to form a complete, dense, and high-strength multilayer substrate blank. S9. Hot cutting and electroplating: The multilayer substrate blank is cut and separated according to the cutting boundaries of each component and module, and then placed in a sintering furnace and heated according to the curve to obtain a cooked porcelain. The lead hole diameter of the cooked porcelain is electroplated with a nickel layer with a thickness of 30μm. S10, Brazing: The lead wire is welded to the lead wire hole of the atmospheric pressure ceramic electrode sheet. After inspecting the product, it is packaged to obtain the atmospheric pressure plasma electrode sheet.

[0031] Example 2 Preparation of MOF metal composites: 15.61 g of glutaric acid, 9.03 g of potassium hydroxide, 19.01 g of nickel acetate tetrahydrate, and 0.99 g of cobalt nitrate hexahydrate were mixed into a 1:1 volume ratio of 400 g of ethanol and deionized water. The mixture was magnetically stirred at 25°C until all components were fully dissolved, yielding a solution. This solution was then transferred to a polytetrafluoroethylene-lined reactor, heated to 180°C, and reacted for 48 hours. The mixture was then allowed to cool naturally to 25°C before being processed using deionized water. The MOF nanomaterials were obtained by washing the material alternately with water and ethanol three times and drying it in a vacuum drying oven at 60°C for 12 hours. 7g of MOF nanomaterials and 66.5g of melamine were added to 500g of ethanol and stirred evenly. After the ethanol evaporated, the mixture was dried in a vacuum oven at 60°C for 6 hours to obtain a mixture. The mixture was heated to 700°C in a tube furnace at a rate of 2°C / min and held at this temperature for 4 hours under nitrogen to obtain the MOF metal composite material.

[0032] Preparation of conductive paste: According to the mass percentage, the conductive slurry contains 2.5 wt% ethyl cellulose, 10 wt% pyrrole, 12 wt% MOF metal material, 2 wt% dispersant, 50 wt% conductive silver powder, and the balance is terpineol. Terpineol, dispersant, and ethyl cellulose are ball-milled at 200 rpm for 30 min. Then, while stirring, polypyrrole, MOF metal composite material, and conductive silver powder are added sequentially, and stirring continues at 300 rpm for 60 min to obtain the conductive slurry. Ambient pressure plasma electrode ceramic sheet is then prepared. S1. Raw material inspection: Inspect the raw materials, take qualified materials, and obtain untreated raw ceramic pieces; S2. Aging: The untreated raw ceramic pieces are subjected to high-temperature aging at 75°C for 18 minutes to obtain raw ceramic pieces. S3. Frame and film application: Fix the green ceramic tile and frame in position using a vacuum adsorption platform, and stick them together with tape. Then apply the film to the Mylar surface. S4. Drilling and Filling: Drilling is performed on the surface of the green ceramic sheet using laser drilling at a frequency of 115 kHz, a power of 71%, and a speed of 410 mm / s. The drilled holes are then trimmed using a frequency of 110 kHz, a power of 68%, and a speed of 400 mm / s. Conductive paste is then filled into the holes on the drilled green ceramic sheet to create vertical pathways for circuit connections between layers. Hole filling is performed using printing. The machine parameters are: pressure 550 N, squeegee position 75 mm, distance from the plate 0.13 mm, printing speed 8 mm / s, and filling speed 10 mm / s, resulting in a ceramic green body. After filling, the surface of the ceramic green body is leveled by adjusting the pressure. S5. Printing: Use screen printing. The printing station and printing machine parameters are as follows: pressure 72N, squeegee position 140mm, distance from the plate 2.0mm, printing speed 40mm / s, and inking speed 60mm / s. S6. Cavity Opening: Based on the cavity structure, a laser is used to open a cavity on a green ceramic sheet with a printed conductor. The parameters of the cavity opening machine are: frequency 100KHz, power 66%, and speed 300mm / s. S7. Screen printing: Using screen printing, the coated screen is printed to obtain a ceramic sheet with a printed circuit pattern. S8. Stacking and isostatic pressing: The ceramic sheets with printed circuit patterns are stacked in the design order to meet the requirements of the composite circuit structure, and to align and accurately position them. During the stacking process, the green ceramic sheets are rotated counterclockwise in sequence according to the flow of the green ceramic sheets. The stacked green ceramic sheets are then bonded together to form a complete, dense, and high-strength multilayer substrate blank. S9. Hot cutting and electroplating: The multilayer substrate blank is cut and separated according to the cutting boundaries of each component and module, and then placed in a sintering furnace and heated according to the curve to obtain a cooked porcelain. The lead hole diameter of the cooked porcelain is electroplated with a nickel layer with a thickness of 30μm. S10, Brazing: The lead wire is welded to the lead wire hole of the atmospheric pressure ceramic electrode sheet. After inspecting the product, it is packaged to obtain the atmospheric pressure plasma electrode sheet.

[0033] Example 3 Preparation of MOF metal composites: 15.61 g of glutaric acid, 9.03 g of potassium hydroxide, 18.96 g of nickel acetate tetrahydrate, and 1.04 g of cobalt nitrate hexahydrate were mixed into a 1:1 volume ratio of 400 g of ethanol and deionized water. The mixture was magnetically stirred at 25°C until all components were fully dissolved, yielding a solution. This solution was then transferred to a polytetrafluoroethylene-lined reactor, heated to 180°C, and reacted for 48 hours. The mixture was then allowed to cool naturally to 25°C before being processed using a deionization process. The MOF nanomaterials were obtained by washing the material alternately with water and ethanol three times and drying it in a vacuum drying oven at 60°C for 12 hours. 7g of MOF nanomaterials and 63g of melamine were added to 500g of ethanol and stirred evenly. After the ethanol evaporated, the mixture was dried in a vacuum oven at 60°C for 6 hours to obtain a mixture. The mixture was heated to 700°C in a tube furnace at a rate of 2°C / min and kept at this temperature for 4 hours under nitrogen to obtain the MOF metal composite material.

[0034] Preparation of conductive paste: According to the mass percentage, the conductive slurry contains 2 wt% ethyl cellulose, 8 wt% pyrrole, 10 wt% MOF metal material, 1.5 wt% dispersant, 55 wt% conductive silver powder, and the balance is terpineol. Terpineol, dispersant, and ethyl cellulose are ball-milled at 200 rpm for 30 min. Then, while stirring, polypyrrole, MOF metal composite material, and conductive silver powder are added sequentially, and stirring continues at 300 rpm for 60 min to obtain the conductive slurry. Ambient pressure plasma electrode ceramic sheet is then prepared. S1. Raw material inspection: Inspect the raw materials, take qualified materials, and obtain untreated raw ceramic pieces; S2. Aging: The untreated raw ceramic pieces are subjected to high-temperature aging at 70°C for 20 minutes to obtain raw ceramic pieces. S3. Frame and film application: Fix the green ceramic tile and frame in position using a vacuum adsorption platform, and stick them together with tape. Then apply the film to the Mylar surface. S4. Drilling and Filling: Drilling is performed on the surface of the green ceramic sheet using laser drilling at a frequency of 115 kHz, a power of 71%, and a speed of 410 mm / s. The drilled holes are then trimmed using a frequency of 110 kHz, a power of 68%, and a speed of 400 mm / s. Conductive paste is then filled into the holes on the drilled green ceramic sheet to create vertical pathways for circuit connections between layers. Hole filling is performed using printing. The machine parameters are: pressure 550 N, squeegee position 75 mm, distance from the plate 0.13 mm, printing speed 8 mm / s, and filling speed 10 mm / s, resulting in a ceramic green body. After filling, the surface of the ceramic green body is leveled by adjusting the pressure. S5. Printing: Use screen printing. The printing station and printing machine parameters are as follows: pressure 72N, squeegee position 140mm, distance from the plate 2.0mm, printing speed 40mm / s, and inking speed 60mm / s. S6. Cavity Opening: Based on the cavity structure, a laser is used to open a cavity on a green ceramic sheet with a printed conductor. The parameters of the cavity opening machine are: frequency 100KHz, power 66%, and speed 300mm / s. S7. Screen printing: Using screen printing, the coated screen is printed to obtain a ceramic sheet with a printed circuit pattern. S8. Stacking and isostatic pressing: The ceramic sheets with printed circuit patterns are stacked in the design order to meet the requirements of the composite circuit structure, and to align and accurately position them. During the stacking process, the green ceramic sheets are rotated counterclockwise in sequence according to the flow of the green ceramic sheets. The stacked green ceramic sheets are then bonded together to form a complete, dense, and high-strength multilayer substrate blank. S9. Hot cutting and electroplating: The multilayer substrate blank is cut and separated according to the cutting boundaries of each component and module, and then placed in a sintering furnace and heated according to the curve to obtain a cooked porcelain. The lead hole diameter of the cooked porcelain is electroplated with a nickel layer with a thickness of 30μm. S10, Brazing: The lead wire is welded to the lead wire hole of the atmospheric pressure ceramic electrode sheet. After inspecting the product, it is packaged to obtain the atmospheric pressure plasma electrode sheet.

[0035] Example 4 Example 4 is based on Example 3. In Example 4, when preparing MOF metal composite material, the amount of nickel acetate tetrahydrate used is 18.77g and the amount of cobalt nitrate hexahydrate used is 1.23g.

[0036] Example 5 Example 5 is based on Example 3. In Example 5, when preparing MOF metal composite material, the amount of nickel acetate tetrahydrate used is 19.1g and the amount of cobalt nitrate hexahydrate used is 0.9g.

[0037] Example 6 Example 6 is based on Example 3. In Example 6, 49g of melamine was used when preparing the MOF metal composite material.

[0038] Example 7 Example 7 is based on Example 3. In Example 7, 77g of melamine was used when preparing the MOF metal composite material.

[0039] Example 8 Example 8 is based on Example 3. In Example 8, the proportion of MOF metal composite material is 5 wt% when preparing the conductive paste.

[0040] Example 9 Example 9 is based on Example 3. In Example 9, the proportion of MOF metal composite material is 15 wt% when preparing the conductive paste.

[0041] Example 10 Example 10 is based on Example 3. In Example 10, the preparation method of the atmospheric pressure plasma electrode ceramic sheet, step S2, has an aging temperature of 55°C.

[0042] Example 11 Example 11 is based on Example 3. In Example 11, the preparation method of the atmospheric pressure plasma electrode ceramic sheet, step S2, has an aging temperature of 85°C.

[0043] Example 12 Example 12 is based on Example 3. In Example 12, the preparation method of the atmospheric pressure plasma electrode ceramic sheet, step S2, has an aging time of 15 min.

[0044] Example 13 Example 13 is based on Example 3. In Example 13, the preparation method of the atmospheric pressure plasma electrode ceramic sheet, step S2, has an aging time of 25 min.

[0045] Comparative Example 1 Comparative Example 1 is based on Example 3, but the raw ceramic pieces were not aged in Comparative Example 1.

[0046] Comparative Example 2 In Comparative Example 2, no MOF metal composite material was added to the conductive paste.

[0047] Performance testing Samples from Examples 1-13 and Comparative Examples 1-2 were taken and subjected to the following performance tests: (1) Conductivity test Using GB / T 17473.1-2008 as the testing reference, a four-probe tester was used to randomly select 5 points on the flat circuit pattern of the sample for measurement, and the average volume resistivity was calculated. Each sample was tested 3 times, the average value was taken, and the test results were filled in Table 1. (2) Impact resistance test Using GB / T 14484-2019 as the testing reference, the impact performance of the samples was tested. Each sample was tested 3 times, the average value was taken, and the test results were filled in Table 1. (3) High temperature resistance test Using GB / T 2423.2-2008 as the testing reference, the temperature resistance of the samples was tested. The samples were kept at 300℃ for 1000 hours, and the resistance change rate was tested. Each sample was tested 3 times, and the average value was taken. The test results were recorded in Table 1.

[0048] Table 1 Performance test results of Examples 1-13 and Comparative Examples 1-2 As shown in Table 1, the volume resistivity of Examples 1-3 is all around 8.5 × 10⁻⁶. -5 The adhesion strength of Ω·cm and below indicates that the electrode ceramic sheet prepared in this application has good electrical conductivity; the adhesion strength of Examples 1-3 is all 46N and above, indicating that the electrode ceramic sheet prepared in this application has good mechanical strength; after high temperature testing, the resistance change rate of Examples 1-3 is all 5.2% and below, indicating that the electrode ceramic sheet prepared in this application has good high temperature resistance.

[0049] In Examples 4 and 5, the mass ratio of nickel acetate tetrahydrate to cobalt nitrate hexahydrate in the preparation of MOF nanomaterials was not within the range specified in this application. When the content of nickel acetate tetrahydrate was too low, excessive cobalt was generated, resulting in a wide diameter distribution of carbon nanotubes grown on the surface of the MOF nanomaterials and the production of amorphous carbon byproducts, which affected the electrical conductivity and increased structural defects in the carbon nanotubes, leading to a decrease in impact strength and thermal conductivity. When the content of nickel acetate tetrahydrate was too high, the cobalt content in the system was insufficient, causing Ni nanoparticles to migrate during high-temperature treatment, affecting the average particle size of subsequent carbon nanotube growth, and reducing the overall quality.

[0050] In Examples 6 and 7, the mass ratio between MOF nanomaterials and melamine during the preparation of MOF nanomaterials was not within the range specified in this application. When the melamine content was too low, it was difficult to provide sufficient carbon source for the growth of carbon nanotubes on the surface of MOF nanomaterials, making it difficult to form a continuous three-dimensional network. As a result, the conductivity, heat resistance, and impact resistance all decreased. When the melamine content was too high, the excess melamine produced a large number of carbon / nitrogen gaseous species during pyrolysis. Amorphous carbon was deposited in large quantities on the surface of MOF nanomaterials, making it difficult to form carbon nanotubes. This resulted in a decrease in the overall conductivity, heat resistance, and impact resistance of the system.

[0051] In Examples 8 and 9, the proportion of MOF metal composite material in the preparation of conductive paste was not within the above range. When the amount of MOF metal material added was too small, it was difficult to form a through three-dimensional conductive and thermally conductive network after sintering, and the heat dissipation performance was affected, and the mechanical effect was difficult to improve further. When the content of MOF metal material was too high, the viscosity of the conductive paste was too large, the rheological properties decreased, and defects such as screen clogging occurred during screen printing. It was also difficult to disperse evenly, which reduced the bonding ability with the ceramic matrix and reduced various properties.

[0052] The aging temperature of Example 10 was 55°C and the aging time of Example 12 was 15 minutes. Both of these conditions resulted in insufficient aging, which led to inadequate stress release inside the green ceramic sheet, reduced uniformity of organic carrier distribution, and caused ceramic sheet warping and cracking. Furthermore, the accuracy of positioning and drilling decreased.

[0053] The aging temperature in Example 11 was 85°C, and the aging time in Example 13 was 25 minutes. Excessive temperature or excessive aging time will lead to over-aging, which will make the green ceramic tile brittle and lose its toughness. During the subsequent film application and drilling process, cracks will be generated, affecting the quality of subsequent products.

[0054] In Comparative Example 1, no aging treatment was performed on the green ceramic chips, resulting in a decrease in the uniformity of the green ceramic chip components. This led to a decrease in the stability of the green ceramic chips, causing cracks and other defects during subsequent decomposition and other processing, which affected the product quality.

[0055] In Comparative Example 2, the conductive paste did not contain MOF composite material, lacking a thermally conductive network, and it was difficult to further enhance the overall mechanical reinforcing phase of the product, resulting in decreased performance.

[0056] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. A method for preparing a ceramic sheet for an atmospheric pressure plasma electrode, characterized in that: Includes the following steps: S1. Raw material inspection: Inspect the raw materials, then take the materials to obtain raw ceramic shards; S2. Aging: The raw ceramic tiles are aged by heating. S3. Frame and film application: Fix the green ceramic tile to the frame using a vacuum adsorption platform and then apply the film. Finally, apply a micro-adhesive film to the Mylar surface. S4. Drilling and filling: Drill holes on the surface of the raw ceramic sheet to form through holes, then fill the through holes with conductive paste, and then adjust the pressure to make the surface of the ceramic body smooth and flat. S5. Printing: By screen printing, a printing screen coated with conductive paste is placed on the ceramic blank, and then pressure is applied, and the conductive paste is transferred from the holes of the screen to the ceramic blank. S6. Cavity Opening: Based on the provided cavity structure, a laser is used to open a cavity on a green ceramic sheet with a printed conductor. S7. Screen Printing: Using screen printing, circuit patterns are printed on the surface of the raw ceramic sheet through the prepared screen printing hole to obtain a ceramic sheet with printed circuit patterns. S8. Stacking and Isostatic Pressing: The ceramic sheets with printed circuit patterns are stacked in the design order. Then, the temperature and pressure are adjusted, and the stacked green ceramic sheets are placed in an isostatic press to bond the multiple green ceramic sheets together to obtain a multi-layer substrate blank. S9. Hot cutting and electroplating: The multilayer substrate blank is cut and separated according to the cutting boundaries of each component and module, and then placed in a sintering furnace for sintering. Then, the lead hole diameter of the atmospheric pressure plasma electrode sheet is electroplated. S10, Brazing: The lead wire is welded to the lead wire hole of the atmospheric pressure ceramic electrode sheet. After inspecting the product, it is packaged to obtain the atmospheric pressure plasma electrode sheet.

2. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 1, characterized in that: In step S2, the aging temperature is 65-75℃ and the aging time is 18-22min. In step S4, the drilling method is either mechanical drilling or laser drilling.

3. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 2, characterized in that: The laser drilling frequency is 115KHz, the power is 71%, and the drilling speed is 410mms. After laser drilling, the hole is then repaired at a frequency of 110KHz, a power of 68%, and a speed of 400mms.

4. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 1, characterized in that: In step S5, the conductive paste includes terpineol, MOF metal composite material, polypyrrole, and dispersant.

5. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 4, characterized in that: The raw materials for the MOF metal composite material include cobalt nitrate hexahydrate, nickel acetate tetrahydrate, glutaric acid, and melamine.

6. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 5, characterized in that: The MOF metal composite material was prepared by the following method: Glutaric acid, potassium hydroxide, hydrated nickel acetate, water and ethanol were mixed, stirred and transferred to a reaction vessel, heated and reacted, then cooled, washed and dried to obtain MOF nanomaterials; MOF nanomaterials, melamine and ethanol were mixed and dried to obtain dried material, which was then calcined and kept at a certain temperature to finally obtain MOF metal composite material.

7. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 6, characterized in that: The mass ratio between nickel acetate tetrahydrate and cobalt nitrate hexahydrate is (17.2-19.2):

1.

8. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 6, characterized in that: The mass ratio of the MOF nanomaterial to melamine is 1:(8.5-9.5).

9. The method for preparing a ceramic sheet for an atmospheric pressure plasma electrode according to claim 6, characterized in that: The proportion of MOF metal composite material in the conductive paste is 8-12 wt%.

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