Ceramic substrate laser processing method

Abstract

The invention discloses a laser processing method for a ceramic substrate, and relates to the technical field of advanced packaging of semiconductors, the ceramic substrate is prepared by adopting a method of filling slurry on the ceramic substrate, filling blind holes, magnetron sputtering and electrocoppering, and graphene oxide nanosheets are used as carriers in electrocoppering liquid. Micron boron nitride and nano silicon dioxide are used as layer struts to be inserted between graphene oxide nanosheet layers, and a corrosion inhibitor benzotriazole is added, so that the corrosion resistance of the ceramic substrate is enhanced; chloride ions, polyethylene glycol, sodium 3, 3 '-dithiodipropane sulfonate and polyethyleneimine in the electroplating solution interact with one another, so that a plating layer is bright and leveled; and chloride ions can form a layer of anode film on the anode and are complexed with cuprous ions, so that copper deposition is prevented, and the stability of the electroplating liquid is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of advanced semiconductor packaging, in particular to a laser processing method for a ceramic substrate. Background Art

[0002] As electronic devices develop towards miniaturization, lightweight, high integration, high reliability and low cost, the microwave circuit field has put forward an urgent demand for multifunctional microwave multi-chip module stacking technology in the vertical direction of the Z axis. In order to realize the vertically interconnected 3D multi-chip module structure, a ceramic substrate was prepared by using filling slurry and magnetron sputtering and direct electroplating copper filling method. The copper-plated area of ​​the prepared ceramic substrate is prone to corrosion.

[0003] In order to solve the problem that ceramic substrates are easily corroded, the present invention provides a laser processing method for ceramic substrates. Summary of the Invention

[0004] The object of the present invention is to provide a laser processing method for a ceramic substrate to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A laser processing method for a ceramic substrate comprises the following steps:

[0007] Step 1: Laser drilling a through hole on the substrate to form a laser through hole on the substrate, cleaning, polishing, soaking in sulfuric acid for 1 to 3 hours, cleaning, and drying to obtain a drilled ceramic tile;

[0008] Step 2: Laser-drill the drilled ceramic sheet to form a blind hole, clean, polish, soak in sulfuric acid for 1 to 3 hours, clean, and blow dry; magnetron sputter titanium copper to obtain a ceramic substrate with a sputtering seed layer;

[0009] Step 3: placing the ceramic substrate with the sputtered seed layer into a hole-filling electroplating solution, performing electroplating, grinding and polishing to obtain a ceramic substrate.

[0010] A more optimized method for preparing the substrate is: take a ceramic sheet, coat a layer of nano-silver paste on the surface, take a copper sheet, place it on the surface of the ceramic sheet coated with the nano-silver paste, vacuum sinter, clean, soak in an alcohol solution for 3 to 5 minutes, and dry to obtain a substrate.

[0011] Another more optimized method for preparing the substrate is: selecting a ceramic sheet, coating a layer of copper slurry on one side of the ceramic sheet, vacuum curing, cleaning, soaking in an alcohol solution for 5 to 7 minutes, and drying to obtain a substrate.

[0012] The more optimized parameters for laser drilling are: setting the laser power to 30-40W, the frequency to 500-700Hz, the speed to 80-100mm / s, and the drilling rate to 800-1000 holes / min.

[0013] The parameters of the magnetron sputtering titanium copper are more optimized as follows: the sputtering thickness of the titanium layer is set to 0.06-0.08 μm, the sputtering power is set to 5-7 kW, the thickness of the copper layer is set to 0.8-1.0 μm, and the sputtering power is set to 6-8 kW.

[0014] More optimized, in step three, the titanium iridium ruthenium mesh is the anode and the ceramic substrate is the cathode, and the electroplating solution includes the following substances: copper sulfate: 220-240 g / L, sulfuric acid: 60-80 g / L, chloride ion: 50-70 ppm, complex: 6-8 g / L, inhibitor: polyethylene glycol 10-12 g / L, brightener: sodium polydisulfide dipropylene sulfonate 10-12 g / L, leveling agent: polyethyleneimine 10-12 g / L.

[0015] The most optimized method for preparing the nano silver paste is as follows:

[0016] S1: Take phenolic resin, heat, evacuate, cool, add isocyanate-terminated polybutadiene liquid rubber, heat, react for 6-8 hours, and cool to obtain modified phenolic resin;

[0017] S2: Take molybdenum disulfide, add benzyl alcohol solution and modified phenolic resin, ultrasonically disperse for 1 to 3 hours, add polydimethylsiloxane and polyetheramine, stir for 1 to 3 hours to obtain a mixture; take deionized water, add ethylene glycol, heat in a water bath, add nanosilver particles, stir evenly, add ethyl cellulose and trisodium citrate, ultrasonically disperse for 1 to 3 hours, add the mixture, ultrasonically disperse for 1 to 3 hours, grind to a fineness of 10 nm, and prepare nanosilver paste.

[0018] A more optimized method for preparing the composite is as follows: take γ-aminopropyltriethoxysilane, add ethanol solution, add glacial acetic acid dropwise to adjust the pH to 4, stir for 1 to 3 hours, add micron boron nitride and nano-silica, stir for 8 to 10 hours, wash, dry, add N,N-dimethylformamide, add modified graphene oxide nanosheets, add benzotriazole, ultrasonically disperse for 5 to 7 hours, wash, and dry to obtain a composite.

[0019] A more optimized method for preparing modified graphene oxide nanosheets is as follows: taking flake graphite, adding sodium nitrate and concentrated sulfuric acid, stirring and reacting in an ice-water bath for 40 to 60 minutes, adding potassium permanganate, stirring for 2 to 4 hours, heating in a water bath, reacting for 3 to 5 hours, adding deionized water dropwise, heating in an oil bath and reacting for 20 to 40 minutes, adding hydrogen peroxide, stirring for 20 to 40 minutes, washing, centrifuging, ultrasonically dispersing for 1 to 3 hours, and centrifuging to obtain a graphene oxide solution; taking the graphene oxide solution, adding deionized water, ultrasonically dispersing for 60 to 80 minutes, centrifuging, filtering to obtain graphene oxide nanosheets, adding a crosslinking agent glutaraldehyde dropwise, reacting for 5 to 7 hours, heating and reacting for 6 to 8 hours, washing, and obtaining modified graphene oxide nanosheets.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Chloride ions are added to the electroplating solution. Chloride ions interact with brighteners and levelers to make the coating bright and leveled. Chloride ions can form an anodic film at the anode, complex with cuprous ions, prevent copper deposition, and enhance the stability of the electroplating solution.

[0022] 2. The brightener is selected as sodium polydisulfide dipropane sulfonate. During the electroplating process, the brightener has the effect of refining the grains, making the crystal nuclei densely distributed and making the copper plating layer smooth; the inhibitor is selected as polyethylene glycol, which can form a complex with chloride ions and cuprous ions, adsorb on the cathode surface, produce a plugging pinning effect, and prevent copper ions or cuprous ions from diffusing to the copper plate surface.

[0023] 3. Graphene oxide nanosheets have a large specific surface area and are prone to agglomeration. The strong van der Waals force between graphene oxide sheets makes it difficult for graphene oxide to have good dispersion in the solvent and maintain the stability of the solvent. Therefore, a cross-linking agent glutaraldehyde is used, and micron boron nitride and nano-silica are added. Micron-sized boron nitride is used as interlayer pillars to support and adjust the interlayer distance, and nano-sized silica fills the gaps to enhance the stability of graphene oxide nanosheets in the electroplating solution, thereby forming a protective film on the ceramic substrate to prevent corrosion of the ceramic substrate.

[0024] 4. Graphene oxide nanosheets are two-dimensional network structures with high aspect ratio, high strength and excellent physical barrier properties. They can effectively isolate corrosive media such as oxygen and water, slowing the speed at which corrosive media reach the substrate, thereby slowing down the corrosion of ceramic substrates. The conductivity of graphene oxide nanosheets can effectively passivate the plated metal, further enhancing the corrosion resistance of the ceramic substrate.

[0025] 5. Micron boron nitride and nano silicon dioxide have good chemical stability, wear resistance and corrosion resistance. When added to the electroplating solution and electroplated onto the ceramic substrate, they can effectively slow down the corrosion process of the ceramic substrate and enhance the corrosion resistance of the ceramic substrate.

[0026] 6. Benzotriazole can form a protective film on the metal surface. This film can be physically adsorbed on the metal surface to form a dense protective layer, preventing corrosive substances from directly contacting the metal, effectively interfering with the electrochemical process of the corrosion reaction, and thus significantly inhibiting the corrosion rate of the metal.

[0027] 7. The interlayer bonding force of molybdenum disulfide is small, and it has wear-resistant lubricating effect; the phenolic resin is modified by using terminal isocyanate liquid rubber, and the isocyanate group in the terminal isocyanate liquid rubber reacts with the hydroxyl group in the phenolic resin to generate a block polymer, forming an interpenetrating polymer network system, which can effectively improve the wear resistance of the phenolic resin; adding modified phenolic resin and molybdenum disulfide to the nano silver paste effectively improves the wear resistance of the nano silver paste. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0029] The sources and types of the substances involved in the present invention are not particularly limited, and exemplary examples include:

[0030] The phenolic resin is R012974-500g, provided by Beijing Naxi Biochemical Technology Co., Ltd.; the isocyanate-terminated polybutadiene liquid rubber is TY-IRI-II, provided by Tianyuan Aviation Materials (Yingkou) Technology Co., Ltd.; the ethylene glycol is E119700, provided by Shanghai Aladdin Biochemical Technology Co., Ltd.; the silver nanoparticles are XFJ63, with a particle size of 20 nm, provided by Nanjing Xianfeng Nanomaterials Technology Co., Ltd.; the ethyl cellulose is HBWS-166, provided by Hubei Weishi Chemical Reagent Co., Ltd.; trisodium citrate is A3174, provided by Beijing Kangruina Biotechnology Co., Ltd.; nano copper powder is XFJ10, with a particle size of 10 nm, provided by Nanjing Xianfeng Nanomaterials Technology Co., Ltd.; molybdenum disulfide is JYS12, with a particle size of 20 nm, provided by Wuhan Jiyesheng Chemical Co., Ltd.; flake graphite is A00843, with a particle size of 4 nm, provided by Wuhan Jiyesheng Chemical Co., Ltd.; glutaraldehyde is JYS154, provided by Wuhan Jiyesheng Chemical Co., Ltd. The CAS number of γ-aminopropyltriethoxysilane is 919-30-2, provided by Nantong Runfeng Petrochemical Co., Ltd.; the product number of micron boron nitride is HZ-BN-01, with a particle size of 4μm, provided by Hebei Huazuan Alloy Welding Materials Co., Ltd.; the product number of nano-silica is S817575, with a particle size of 10nm, provided by Shanghai Yunguan Mechanical and Electrical Equipment Co., Ltd.; the product number of N,N-dimethylformamide is Jk-G4340, provided by Shanghai Jingkang Bioengineering Co., Ltd.; the product number of copper sulfate is C1297-1 00G, provided by Zhejiang Yigao Biotechnology Co., Ltd.; the product number of sulfuric acid is S477360, provided by Shanghai Aladdin Biochemical Technology Co., Ltd.; the product number of polyethylene glycol is 0052, provided by Xi'an Jinxiang Pharmaceutical Excipients Co., Ltd.; the product number of sodium polydisulfide bispropane sulfonate is 077, provided by sodium polydisulfide bispropane sulfonate; the product number of polyethyleneimine is Y14868, provided by Beijing Biolab Technology Co., Ltd.; the product number of benzotriazole is B101002-500g, provided by Shanghai Aladdin Biochemical Technology Co., Ltd.

[0031] Example 1: A method for laser processing a ceramic substrate:

[0032] Step 1: (1) 10 g of phenolic resin was heated to 120° C., vacuumed, cooled to 80° C., 3 g of isocyanate-terminated polybutadiene liquid rubber was added, heated to 100° C., reacted for 6 h, and cooled to obtain a modified phenolic resin;

[0033] (2) 3 g of molybdenum disulfide was added to 20 mL of benzyl alcohol solution and 5 g of modified phenolic resin, and ultrasonically dispersed for 1 h. 2 g of defoaming agent polydimethylsiloxane and 2 g of curing agent polyetheramine D230 were added and stirred for 1 h to obtain a mixture;

[0034] (3) Take 50 mL of deionized water, add 0.5 g of ethylene glycol, heat in a water bath to 80° C., add 5 g of nanosilver particles, stir evenly, add 0.2 g of ethyl cellulose and 0.5 g of trisodium citrate, ultrasonically disperse for 1 h, add 1 g of the mixture, ultrasonically disperse for 1 h, grind in a grinder, control the fineness of the silver paste to 10 nm, and prepare a nanosilver paste;

[0035] (4) Select a copper sheet with a thickness of 100 μm and the same size as the solder sheet for standby use; select a ceramic sheet with a thickness of 0.38 mm and a size of 3 inches, apply a layer of nano-silver paste on the surface of the ceramic sheet to a thickness of 20 μm, place the copper sheet on the surface of the ceramic sheet coated with the nano-silver paste, sinter one side at 250°C in a vacuum environment, wash in a 2% dilute hydrochloric acid solution for 0.1 min, put into an alcohol solution, ultrasonically disperse for 3 min, and dry to obtain a substrate;

[0036] (5) Laser drilling holes on the substrate, irradiating the substrate surface with a laser beam, setting the laser power to 30 W, the frequency to 500 Hz, the speed to 80 mm / s, and the drilling rate to 800 holes / min, heating and evaporating the substrate to form laser holes, cleaning, polishing, soaking in 0.1 mol sulfuric acid for 1 hour, ultrasonically cleaning with ultrapure water for 5 minutes, ultrasonically cleaning with alcohol for 3 minutes, and drying to obtain a drilled ceramic tile;

[0037] (6) The drilled ceramic sheet is laser drilled, and the holes are repeatedly drilled in the already drilled area to the position of the copper sheet to form a blind hole, cleaned, polished, soaked in 0.1 mol sulfuric acid for 1 hour, ultrasonically cleaned in ultrapure water for 5 minutes, ultrasonically cleaned in alcohol for 3 minutes, and blown dry; magnetron sputtering of titanium copper is performed as a seed layer for copper plating, and the sputtering thickness of the titanium layer is set to 0.06 μm, the sputtering power is 5 kW, the thickness of the copper layer is 0.8 μm, and the sputtering power is 6 kW to obtain a ceramic substrate with a sputtering seed layer;

[0038] Step 2: (1) Take 3.3 g of flake graphite, add 1.2 g of sodium nitrate and 50 mL of concentrated sulfuric acid, stir and react in an ice-water bath for 40 min, add 5.4 g of potassium permanganate, stir for 2 h, heat in a water bath to 40°C, react for 3 h, add 100 mL of deionized water dropwise, heat in an oil bath to 100°C and react for 20 min, add 15 mL of hydrogen peroxide, stir for 20 min, wash, centrifuge, ultrasonically disperse for 1 h, and centrifuge to obtain a graphene oxide solution;

[0039] (2) 4 mL of graphene oxide solution was added to 100 mL of deionized water, ultrasonically dispersed for 60 min, centrifuged, and filtered to obtain graphene oxide nanosheets. 3 mL of cross-linking agent glutaraldehyde was added dropwise, reacted for 5 h, heated to 60 ° C for 6 h, and washed to obtain modified graphene oxide nanosheets;

[0040] (3) 3 g of γ-aminopropyltriethoxysilane was added to 100 mL of ethanol solution, glacial acetic acid was added dropwise to adjust the pH to 4, the mixture was stirred at 40 ° C for 1 h, 0.5 g of micronized boron nitride and 0.5 g of nano-silica were added, the mixture was stirred at 60 ° C for 8 h, washed, dried, 100 mL of N, N-dimethylformamide was added, 0.3 g of modified graphene oxide nanosheets were added, 4 g of benzotriazole was added, ultrasonic dispersion was performed for 5 h, washed, and dried to obtain a composite;

[0041] Step 3: Place the ceramic substrate with the sputtered seed layer into a hole-filling electroplating solution, with the titanium-iridium-ruthenium mesh as the anode and the ceramic substrate as the cathode. Align the hole position with the anode and perform electroplating. The coating thickness is 4 μm, the DC plating current is 1.5 ASD, and the plating time is 120 min. Set the speed to 30 rpm, use cerium oxide as the grinding medium, and polish for 20 minutes to obtain a ceramic substrate.

[0042] The main components of the electroplating solution are copper sulfate: 220g / L, sulfuric acid: 60g / L, chloride ion: 50ppm, complex: 6g / L, inhibitor: polyethylene glycol 10g / L, brightener: sodium polydisulfide dipropylene sulfonate 10g / L, leveling agent: polyethyleneimine 10g / L.

[0043] Example 2: A method for laser processing a ceramic substrate:

[0044] Step 1: (1) 10 g of phenolic resin was heated to 130° C., vacuumed, cooled to 90° C., 3 g of isocyanate-terminated polybutadiene liquid rubber was added, heated to 110° C., reacted for 7 h, and cooled to obtain a modified phenolic resin;

[0045] (2) 3 g of molybdenum disulfide was added to 20 mL of benzyl alcohol solution and 5 g of modified phenolic resin, and ultrasonically dispersed for 1 h. 2 g of defoaming agent polydimethylsiloxane was added and stirred for 1 h to obtain a mixture;

[0046] (3) Take 50 mL of deionized water, add 0.5 g of ethylene glycol, heat in a water bath to 80 ° C, add 5 g of nano copper powder, stir evenly, add 0.2 g of ethyl cellulose and 0.5 g of trisodium citrate, ultrasonically disperse for 1 h, add 1 g of molybdenum disulfide, ultrasonically disperse for 1 h, grind in a grinder, control the fineness of the silver paste to 10 nm, and prepare a copper slurry;

[0047] (4) A 3-inch ceramic sheet with a thickness of 0.38 mm was selected, and a layer of copper slurry was coated on one side of the ceramic sheet to a thickness of 20 μm. The sheet was vacuum cured at 100°C, cleaned in a 2% dilute hydrochloric acid solution for 2 min, immersed in an alcohol solution, ultrasonically dispersed for 5 min, and dried to obtain a substrate;

[0048] (5) Place the substrate in a laser and irradiate the substrate surface with a laser beam. Set the laser power to 40 W, the frequency to 700 Hz, the speed to 100 mm / s, and the drilling rate to 100 holes / min. Heat and evaporate the substrate to form laser through-holes. Clean and polish it. Soak it in 0.1 mol sulfuric acid for 3 h. Ultrasonic cleaning with ultrapure water for 7 min. Ultrasonic cleaning with alcohol for 6 min. Dry it to obtain a drilled tile.

[0049] (6) Place the drilled ceramic sheet in the laser, repeatedly drill holes in the already drilled area to the copper sheet position to form a blind hole, clean, polish, soak in 0.1 mol sulfuric acid for 3 hours, ultrasonically clean with ultrapure water for 7 minutes, ultrasonically clean with alcohol for 7 minutes, and blow dry; magnetron sputter titanium copper as a seed layer for copper plating, set the sputtering thickness of the titanium layer to 0.06 μm, the sputtering power to 7 kW, the thickness of the copper layer to 0.8 μm, and the sputtering power to 8 kW, to obtain a ceramic substrate with a sputtering seed layer;

[0050] Step 2: (1) Take 3.3 g of flake graphite, add 1.2 g of sodium nitrate and 50 mL of concentrated sulfuric acid, stir and react in an ice-water bath for 60 min, add 5.4 g of potassium permanganate, stir for 4 h, heat in a water bath to 60 ° C, react for 5 h, add 100 mL of deionized water dropwise, heat in an oil bath to 120 ° C and react for 40 min, add 15 mL of hydrogen peroxide, stir for 40 min, wash, centrifuge, ultrasonically disperse for 3 h, and centrifuge to obtain a graphene oxide solution;

[0051] (2) Take 4 mL of graphene oxide solution, add 100 mL of deionized water, ultrasonically disperse for 80 min, centrifuge, filter to obtain graphene oxide nanosheets, dropwise add 3 mL of cross-linking agent glutaraldehyde, react for 7 h, heat to 80 ° C for 10 h, wash, and obtain modified graphene oxide nanosheets;

[0052] (3) 3 g of γ-aminopropyltriethoxysilane was added to 100 mL of ethanol solution, glacial acetic acid was added dropwise to adjust the pH to 4, the mixture was stirred at 60 ° C for 3 h, 0.5 g of micronized boron nitride and 0.5 g of nano-silica were added, the mixture was stirred at 80 ° C for 10 h, washed, dried, 100 mL of N, N-dimethylformamide was added, 0.3 g of modified graphene oxide nanosheets were added, 4 g of benzotriazole was added, ultrasonic dispersion was performed for 7 h, washed, and dried to obtain a composite;

[0053] Step 3: Place the ceramic substrate with the sputtered seed layer into a hole-filling electroplating solution, with the titanium-iridium-ruthenium mesh as the anode and the ceramic substrate as the cathode. Align the hole position with the anode and perform electroplating. The coating thickness is 4 μm, the DC electroplating current is 2.5 ASD, and the electroplating time is 140 min. Set the speed to 50 rpm, use cerium oxide as the grinding medium, and polish for 40 minutes to obtain a ceramic substrate.

[0054] The main components of the electroplating solution are copper sulfate: 230g / L, sulfuric acid: 60g / L, chloride ion: 50ppm, complex: 8g / L, inhibitor: polyethylene glycol 12g / L, brightener: sodium polydisulfide dipropylene sulfonate 12g / L, leveling agent: polyethyleneimine 12g / L.

[0055] Example 3: A method for laser processing a ceramic substrate:

[0056] Step 1: (1) 10 g of phenolic resin was heated to 140° C., vacuumed, cooled to 100° C., 3 g of isocyanate-terminated polybutadiene liquid rubber was added, heated to 120° C., reacted for 8 h, and cooled to obtain a modified phenolic resin;

[0057] (2) 3 g of molybdenum disulfide was added to 20 mL of benzyl alcohol solution and 5 g of modified phenolic resin, and ultrasonically dispersed for 3 h. 2 g of defoaming agent polydimethylsiloxane was added and stirred for 3 h to obtain a mixture;

[0058] (3) Take 50 mL of deionized water, add 0.5 g of ethylene glycol, heat in a water bath to 90° C., add 5 g of nanosilver particles, stir evenly, add 0.2 g of ethyl cellulose and 0.5 g of trisodium citrate, ultrasonically disperse for 3 h, add 1 g of the mixture, ultrasonically disperse for 1 h, and grind in a grinder to control the fineness of the silver paste to 15 nm and the viscosity to 12 Pa·s, thereby preparing a nanosilver paste;

[0059] (4) Select a copper sheet with a thickness of 100 μm and the same size as the solder sheet for standby use; select a ceramic sheet with a thickness of 0.38 mm and a size of 3 inches, apply a layer of nano-silver paste on the surface of the ceramic sheet to a thickness of 20 μm, place the copper sheet on the surface of the ceramic sheet coated with the nano-silver paste, sinter one side at 280°C in a vacuum environment, wash in a 2% dilute hydrochloric acid solution for 1 min, soak in an alcohol solution, ultrasonically disperse for 5 min, and dry to obtain a substrate;

[0060] (5) Place the substrate in a laser and irradiate the substrate surface with a laser beam. Set the laser power to 35 W, the frequency to 600 Hz, the speed to 90 mm / s, and the drilling rate to 900 holes / min. Heat and evaporate the substrate to form laser through-holes. Clean and polish it. Soak it in 0.1 mol sulfuric acid for 3 h. Ultrasonic clean it with ultrapure water for 6 min. Ultrasonic clean it with alcohol for 5 min. Dry it to obtain a drilled tile.

[0061] (6) Place the drilled ceramic piece into the laser, repeat drilling at the already drilled place to the position of the copper piece to form a blind hole, clean, polish, soak in 0.1 mol sulfuric acid for 2 hours, ultrasonically clean with ultrapure water for 6 minutes, ultrasonically clean with alcohol for 4 minutes, and blow dry; magnetron sputter titanium copper as the seed layer for copper plating, set the sputtering thickness of the titanium layer to 0.06 μm, the sputtering power to 6 kW, the thickness of the copper layer to 0.8 μm, and the sputtering power to 7 kW, to obtain a ceramic substrate with a sputtering seed layer;

[0062] Step 2: (1) Take 3.3 g of flake graphite, add 1.2 g of sodium nitrate and 50 mL of concentrated sulfuric acid, stir and react in an ice-water bath for 50 min, add 5.4 g of potassium permanganate, stir for 3 h, heat in a water bath to 50° C., react for 4 h, add 100 mL of deionized water dropwise, heat in an oil bath to 110° C., react for 30 min, add 15 mL of hydrogen peroxide, stir for 30 min, wash, centrifuge, ultrasonically disperse for 2 h, and centrifuge to obtain a graphene oxide solution;

[0063] (2) 4 mL of graphene oxide solution was added to 100 mL of deionized water, ultrasonically dispersed for 70 min, centrifuged, and filtered to obtain graphene oxide nanosheets. 3 mL of cross-linking agent glutaraldehyde was added dropwise, reacted for 6 h, heated to 70 ° C for 8 h, and washed to obtain modified graphene oxide nanosheets;

[0064] (3) 3 g of γ-aminopropyltriethoxysilane was added to 100 mL of ethanol solution, glacial acetic acid was added dropwise to adjust the pH to 4, the mixture was stirred at 50 ° C for 3 h, 0.5 g of micronized boron nitride and 0.5 g of nano-silica were added, the mixture was stirred at 70 ° C for 9 h, washed, dried, 100 mL of N, N-dimethylformamide was added, 0.3 g of modified graphene oxide nanosheets were added, 4 g of benzotriazole was added, ultrasonic dispersion was performed for 7 h, washed, and dried to obtain a composite;

[0065] Step 3: Place the ceramic substrate with the sputtered seed layer into a hole-filling electroplating solution, with the titanium-iridium-ruthenium mesh as the anode and the ceramic substrate as the cathode. Align the hole position with the anode and perform electroplating. The coating thickness is 4 μm, the DC plating current is 2 ASD, and the plating time is 130 min. Set the speed to 40 rpm, use cerium oxide as the grinding medium, and polish for 30 minutes to obtain a ceramic substrate.

[0066] The main components of the electroplating solution are copper sulfate: 240g / L, sulfuric acid: 70g / L, chloride ion: 80ppm, complex: 7g / L, inhibitor: polyethylene glycol 11g / L, brightener: sodium polydisulfide dipropylene sulfonate 11g / L, leveling agent: polyethyleneimine 11g / L.

[0067] Comparative Example 1: No graphene oxide nanosheets were added, and the rest was referred to Example 1. The specific operations were as follows:

[0068] Step 2: (1) Take 3 g of γ-aminopropyltriethoxysilane, add 100 mL of ethanol solution, add glacial acetic acid dropwise to adjust the pH to 4, stir at 40°C for 1 hour, add 0.5 g of micron boron nitride and 0.5 g of nano-silica, stir at 60°C for 8 hours, add 4 g of benzotriazole, ultrasonically disperse for 5 hours, wash, and dry to obtain a complex.

[0069] Comparative Example 2: No micron boron nitride was added, and the remaining operations were the same as in Example 1. The specific operations were as follows:

[0070] Step 2: (1) Take 3.3 g of flake graphite, add 1.2 g of sodium nitrate and 50 mL of concentrated sulfuric acid, stir and react in an ice-water bath for 40 min, add 5.4 g of potassium permanganate, stir for 2 h, heat in a water bath to 40°C, react for 3 h, add 100 mL of deionized water dropwise, heat in an oil bath to 100°C and react for 20 min, add 15 mL of hydrogen peroxide, stir for 20 min, wash, centrifuge, ultrasonically disperse for 1 h, and centrifuge to obtain a graphene oxide solution;

[0071] (2) 4 mL of graphene oxide solution was added to 100 mL of deionized water, ultrasonically dispersed for 60 min, centrifuged, and filtered to obtain graphene oxide nanosheets. 3 mL of cross-linking agent glutaraldehyde was added dropwise, reacted for 5 h, heated to 60 ° C for 6 h, and washed to obtain modified graphene oxide nanosheets;

[0072] (3) Take 3 g of γ-aminopropyltriethoxysilane, add 100 mL of ethanol solution, add glacial acetic acid dropwise to adjust the pH to 4, stir at 40 ° C for 1 h, add 0.5 g of nano-silica, stir at 60 ° C for 8 h, wash, dry, add 100 mL of N, N-dimethylformamide, add 0.3 g of modified graphene oxide nanosheets, add 4 g of benzotriazole, ultrasonically disperse for 5 h, wash, and dry to obtain a composite.

[0073] Comparative Example 3: No nano-silicon dioxide was added, and the remaining operations were the same as in Example 1. The specific operations were as follows:

[0074] Step 2: (1) Take 3.3 g of flake graphite, add 1.2 g of sodium nitrate and 50 mL of concentrated sulfuric acid, stir and react in an ice-water bath for 40 min, add 5.4 g of potassium permanganate, stir for 2 h, heat in a water bath to 40°C, react for 3 h, add 100 mL of deionized water dropwise, heat in an oil bath to 100°C and react for 20 min, add 15 mL of hydrogen peroxide, stir for 20 min, wash, centrifuge, ultrasonically disperse for 1 h, and centrifuge to obtain a graphene oxide solution;

[0075] (2) 4 mL of graphene oxide solution was added to 100 mL of deionized water, ultrasonically dispersed for 60 min, centrifuged, and filtered to obtain graphene oxide nanosheets. 3 mL of cross-linking agent glutaraldehyde was added dropwise, reacted for 5 h, heated to 60 ° C for 6 h, and washed to obtain modified graphene oxide nanosheets;

[0076] (3) Take 3 g of γ-aminopropyltriethoxysilane, add 100 mL of ethanol solution, add glacial acetic acid dropwise to adjust the pH to 4, stir at 40 ° C for 1 hour, add 0.5 g of micron boron nitride, stir at 60 ° C for 8 hours, wash, dry, add 100 mL of N, N-dimethylformamide, add 0.3 g of modified graphene oxide nanosheets, add 4 g of benzotriazole, ultrasonically disperse for 5 hours, wash, and dry to obtain a composite.

[0077] Comparative Example 4: Without adding benzotriazole, the rest is the same as in Example 1, and the specific operation is as follows:

[0078] Step 2: (1) Take 3.3 g of flake graphite, add 1.2 g of sodium nitrate and 50 mL of concentrated sulfuric acid, stir and react in an ice-water bath for 40 min, add 5.4 g of potassium permanganate, stir for 2 h, heat in a water bath to 40°C, react for 3 h, add 100 mL of deionized water dropwise, heat in an oil bath to 100°C and react for 20 min, add 15 mL of hydrogen peroxide, stir for 20 min, wash, centrifuge, ultrasonically disperse for 1 h, and centrifuge to obtain a graphene oxide solution;

[0079] (2) 4 mL of graphene oxide solution was added to 100 mL of deionized water, ultrasonically dispersed for 60 min, centrifuged, and filtered to obtain graphene oxide nanosheets. 3 mL of cross-linking agent glutaraldehyde was added dropwise, reacted for 5 h, heated to 60 ° C for 6 h, and washed to obtain modified graphene oxide nanosheets;

[0080] (3) Take 3 g of γ-aminopropyltriethoxysilane, add 100 mL of ethanol solution, add glacial acetic acid dropwise to adjust the pH to 4, stir at 40 ° C for 1 hour, add 0.5 g of micron boron nitride and 0.5 g of nano-silica, stir at 60 ° C for 8 hours, wash, dry, add 100 mL of N, N-dimethylformamide, add 0.3 g of modified graphene oxide nanosheets, ultrasonically disperse for 5 hours, wash, and dry to obtain a composite.

[0081] Comparative Example 5: No isocyanate-terminated polybutadiene liquid rubber-modified phenolic resin was added. The rest was similar to Example 1. The specific operation was as follows:

[0082] Step 1: (1) 3 g of molybdenum disulfide was added to 20 mL of benzyl alcohol solution and 5 g of phenolic resin, and ultrasonically dispersed for 1 h. 2 g of defoaming agent polydimethylsiloxane and 2 g of curing agent polyetheramine D230 were added, and stirred for 1 h to obtain a mixture;

[0083] (2) Take 50 mL of deionized water, add 0.5 g of ethylene glycol, heat in a water bath to 80° C., add 5 g of nanosilver particles, stir evenly, add 0.2 g of ethyl cellulose and 0.5 g of trisodium citrate, ultrasonically disperse for 1 h, add 1 g of the mixture, ultrasonically disperse for 1 h, grind in a grinder, control the fineness of the silver paste to 10 nm, and prepare a nanosilver paste;

[0084] (3) Select a copper sheet with a thickness of 100 μm and the same size as the solder sheet for standby use; select a ceramic sheet with a thickness of 0.38 mm and a size of 3 inches, apply a layer of nano-silver paste on the surface of the ceramic sheet to a thickness of 20 μm, place the copper sheet on the surface of the ceramic sheet coated with nano-silver paste, sinter one side at 250°C in a vacuum environment, wash in a 2% dilute hydrochloric acid solution for 0.1 min, put into an alcohol solution, ultrasonically disperse for 3 min, and dry to obtain a substrate;

[0085] (4) Laser drilling holes on the substrate, irradiating the substrate surface with a laser beam, setting the laser power to 30 W, the frequency to 500 Hz, the speed to 80 mm / s, and the drilling rate to 800 holes / min, heating and evaporating the substrate to form laser holes, cleaning, polishing, soaking in 0.1 mol sulfuric acid for 1 hour, ultrasonically cleaning with ultrapure water for 5 minutes, ultrasonically cleaning with alcohol for 3 minutes, and drying to obtain a drilled ceramic tile;

[0086] (5) The drilled ceramic piece is laser drilled, and the holes are repeatedly drilled in the already drilled place to the position of the copper piece to form a blind hole, which is then cleaned, polished, and immersed in 0.1 mol sulfuric acid for 1 hour, ultrasonically cleaned with ultrapure water for 5 minutes, ultrasonically cleaned with alcohol for 3 minutes, and blown dry; magnetron sputtering of titanium copper is performed as a seed layer for copper plating, and the sputtering thickness of the titanium layer is set to 0.06 μm, the sputtering power is set to 5 kW, the thickness of the copper layer is set to 0.8 μm, and the sputtering power is set to 6 kW to obtain a ceramic substrate with a sputtering seed layer.

[0087] experiment:

[0088] 1. Salt spray resistance test:

[0089] The ceramic substrates prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were tested at 37° C. with a sodium chloride concentration of 60 g / L for a certain period of time. The conditions of the ceramic substrates were recorded. The results are shown in Table 1 below.

[0090] 2. Wear resistance test:

[0091] Take the ceramic substrates prepared in Examples 1 to 3 and Comparative Examples 1 to 5, select high carbon chromium bearing steel as the grinding material, set the load to 20N, set the turntable speed to 120r / min, and the wear time to 1h. The wear amount is calculated and the data is recorded. The results are shown in Table 1 below.

[0092] Table 1

[0093] Ceramic substrate situation Wear loss mg Example 1 No surface corrosion after 3 hours 0.15 Example 2 No corrosion on the surface after 3 hours 0.14 Example 3 No surface corrosion after 3 hours 0.15 Comparative Example 1 Corrosion spots appear on the surface after 0.5h 0.22 Comparative Example 2 Corrosion spots appear on the surface after 1.5 hours 0.19 Comparative Example 3 Corrosion spots appear on the surface after 1.5 hours 0.20 Comparative Example 4 Corrosion spots appear on the surface after 1 hour 0.16 Comparative Example 5 Corrosion spots appear on the surface after 2.5 hours 0.18

[0094] Conclusion: The ceramic substrates prepared in Examples 1 to 4 have smooth and flat surfaces and good corrosion resistance and wear resistance.

[0095] By comparing Comparative Example 1 and Example 1 without the addition of graphene oxide nanosheets, it can be seen that corrosion spots appear on the surface of the ceramic substrate prepared in Comparative Example 1 after 0.5 h, and the wear amount is 0.22 mg. This is because the graphene oxide nanosheets are a two-dimensional network structure with a high aspect ratio, high strength and excellent physical barrier properties, which can effectively isolate corrosive media such as oxygen and water, delay the speed at which the corrosive media reaches the substrate, thereby slowing down the corrosion of the ceramic substrate.

[0096] Comparison of Comparative Example 2 without adding micron boron nitride, Comparative Example 3 without adding nano-silicon dioxide and Example 1 shows that corrosion spots appear on the surface of the ceramic substrates prepared in Comparative Example 2 and Comparative Example 3 after 2.5 hours, and the wear amount is 0.19 mg and 0.20 mg respectively. Micron boron nitride and nano-silicon dioxide have good chemical stability, wear resistance and corrosion resistance. When added to the electroplating solution and electroplated onto the ceramic substrate, they can effectively slow down the corrosion process of the ceramic substrate and enhance the corrosion resistance of the ceramic substrate.

[0097] Comparison between Comparative Example 4 and Example 1, in which no benzotriazole is added, shows that corrosion spots appear on the surface of the ceramic substrate prepared in Comparative Example 4 after 1 hour, and the wear amount is 0.16 mg. Benzotriazole can form a protective film on the metal surface. This film can be physically adsorbed on the metal surface to form a dense protective layer, preventing corrosive substances from directly contacting the metal, effectively interfering with the electrochemical process of the corrosion reaction, thereby significantly inhibiting the corrosion rate of the metal.

[0098] By comparing Comparative Example 5 in which no other substances are added to the nano-silver paste with Example 1, it can be seen that corrosion spots appear on the surface of the ceramic substrate in Comparative Example 5 after 2.5 hours, and the wear amount is 0.18 mg. This is because the phenolic resin is modified by using terminal isocyanate liquid rubber, and the isocyanate group in the terminal isocyanate liquid rubber reacts with the hydroxyl group in the phenolic resin to generate a block polymer, forming an interpenetrating polymer network system, which can effectively improve the wear resistance of the phenolic resin; adding modified phenolic resin to the nano-silver paste can effectively improve the wear resistance of the nano-silver paste.

[0099] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A laser processing method for a ceramic substrate, characterized in that: The following steps are involved: Step 1: Laser drilling a through hole on the substrate to form a laser through hole on the substrate, cleaning, polishing, soaking in sulfuric acid for 1 to 3 hours, cleaning, and drying to obtain a drilled ceramic tile; Step 2: Laser-drill the drilled ceramic sheet to form a blind hole, clean, polish, soak in sulfuric acid for 1 to 3 hours, clean, and blow dry; magnetron sputter titanium copper to obtain a ceramic substrate with a sputtering seed layer; Step 3: placing the ceramic substrate with the sputtered seed layer into a hole-filling electroplating solution, performing electroplating, grinding and polishing to obtain a ceramic substrate.

2. The laser processing method for a ceramic substrate according to claim 1, characterized in that: The preparation method of the substrate comprises the following steps: taking a ceramic sheet, coating the surface with a layer of nano-silver paste, taking a copper sheet, placing the copper sheet on the surface of the ceramic sheet coated with the nano-silver paste, vacuum sintering, cleaning, soaking in an alcohol solution for 3 to 5 minutes, and drying to obtain the substrate.

3. The laser processing method for a ceramic substrate according to claim 1, wherein: Another method for preparing the substrate is as follows: selecting a ceramic sheet, coating a layer of copper slurry on one side of the ceramic sheet, vacuum curing, cleaning, soaking in an alcohol solution for 5 to 7 minutes, and drying to obtain the substrate.

4. The laser processing method for a ceramic substrate according to claim 1, wherein: The parameters of the laser drilling holes are as follows: setting the laser power to 30-40W, the frequency to 500-700Hz, the speed to 80-100mm / s, and the drilling rate to 800-1000 holes / min.

5. The laser processing method for a ceramic substrate according to claim 1, wherein: The parameters of the magnetron sputtering titanium copper are as follows: setting the sputtering thickness of the titanium layer to 0.06-0.08 μm, the sputtering power to 5-7 kW, the thickness of the copper layer to 0.8-1.0 μm, and the sputtering power to 6-8 kW.

6. The laser processing method for a ceramic substrate according to claim 1, characterized in that: In step three, the titanium iridium ruthenium mesh is the anode and the ceramic substrate is the cathode. The electroplating solution includes the following substances: copper sulfate: 220-240 g / L, sulfuric acid: 60-80 g / L, chloride ion: 50-70 ppm, complex: 6-8 g / L, inhibitor: polyethylene glycol 10-12 g / L, brightener: sodium polydisulfide dipropylene sulfonate 10-12 g / L, leveling agent: polyethyleneimine 10-12 g / L.

7. The laser processing method for a ceramic substrate according to claim 2, characterized in that: The preparation method of the nano silver paste is: The following steps are involved: S1: Take phenolic resin, heat, evacuate, cool, add isocyanate-terminated polybutadiene liquid rubber, heat, react for 6-8 hours, and cool to obtain modified phenolic resin; S2: Take molybdenum disulfide, add benzyl alcohol solution and modified phenolic resin, ultrasonically disperse for 1 to 3 hours, add polydimethylsiloxane and polyetheramine, stir for 1 to 3 hours to obtain a mixture; take deionized water, add ethylene glycol, heat in a water bath, add nanosilver particles, stir evenly, add ethyl cellulose and trisodium citrate, ultrasonically disperse for 1 to 3 hours, add the mixture, ultrasonically disperse for 1 to 3 hours, grind to a fineness of 10 nm, and prepare nanosilver paste.

8. The laser processing method for a ceramic substrate according to claim 6, characterized in that: The preparation method of the composite comprises the following steps: taking γ-aminopropyltriethoxysilane, adding an ethanol solution, dropping glacial acetic acid to adjust the pH to 4, stirring for 1 to 3 hours, adding micron boron nitride and nano-silicon dioxide, stirring for 8 to 10 hours, washing, drying, adding N,N-dimethylformamide, adding modified graphene oxide nanosheets, adding benzotriazole, ultrasonically dispersing for 5 to 7 hours, washing, and drying to obtain the composite.

9. The laser processing method for a ceramic substrate according to claim 8, characterized in that: The preparation method of the modified graphene oxide nanosheets comprises the following steps: taking flake graphite, adding sodium nitrate and concentrated sulfuric acid, stirring and reacting in an ice-water bath for 40 to 60 minutes, adding potassium permanganate, stirring for 2 to 4 hours, heating in a water bath, reacting for 3 to 5 hours, dropwise adding deionized water, heating in an oil bath, reacting for 20 to 40 minutes, adding hydrogen peroxide, stirring for 20 to 40 minutes, washing, centrifuging, ultrasonically dispersing for 1 to 3 hours, and centrifuging to obtain a graphene oxide solution; taking the graphene oxide solution, adding deionized water, ultrasonically dispersing for 60 to 80 minutes, centrifuging, filtering to obtain graphene oxide nanosheets, dropwise adding a crosslinking agent, glutaraldehyde, reacting for 5 to 7 hours, heating for reaction for 6 to 8 hours, and washing to obtain modified graphene oxide nanosheets.

10. A ceramic substrate prepared by the laser processing method for a ceramic substrate according to any one of claims 1 to 9.