299 results about "Tape casting" patented technology

The invention discloses a high-strength and high-toughness aluminum nitride ceramic and a preparation method thereof, and relates to the technical field of ceramics, a sol-gel method is adopted to coat the surface of aluminum nitride with a stable shell layer to form a core-shell structure, meanwhile, the low lattice mismatch rate of a core-shell interface is utilized to reduce thermal resistance, and toughness and thermal conductivity are both considered; according to the external magnetic field tape casting method, the magnetic dipole moment orientation principle is utilized, an external magnetic field is applied in the tape casting stage, the in-plane mechanical property is improved, and the fracture toughness is improved through the magnetism of aluminum nitride whiskers; a reinforcement is introduced to improve the mechanical property and corrosion resistance of the aluminum nitride ceramic material, multi-granularity powder is compounded, large-particle aluminum nitride powder is used as a sintering and heat-conducting framework material, and high activity provided by submicron particles is utilized to promote sintering, so that the sintering temperature of aluminum nitride can be remarkably reduced, and the performance is greatly improved; and the aluminum nitride substrate expands more application fields on a future packaging circuit.

The invention discloses a preparation method of a textured silicon nitride ceramic substrate, and belongs to the technical field of ceramic products. Beta-silicon nitride whiskers with the long diameter of 4-15 microns and the short diameter of 1-3 microns are added into silicon nitride ceramic slurry according to the design, and when the whiskers containing beta-silicon nitride pass through a scraper of a casting machine, the whiskers tend to be directionally arranged in the casting direction, so that a textured structure is generated in the silicon nitride ceramic substrate. The textured structure is beneficial to improving the three-point bending strength, the fracture toughness and the thermal conductivity in the horizontal direction of the ceramic substrate.

The invention relates to the technical field of composite materials, in particular to a heat and sound insulation PVB intermediate film and a preparation method thereof. The problem that a PVB intermediate film is insufficient in heat insulation and aging resistance is solved. The preparation method comprises the following steps: pre-plasticizing PVB resin, shearing and mixing the pre-plasticized PVB resin and silane coupling agent modified enhanced nano cellulose, sequentially adding additives such as a plasticizer, molybdenum trioxide loaded lanthanum hexaboride, a composite light stabilizer and modified cerium oxide, and carrying out tape casting and hot pressing treatment to obtain the PVB intermediate film. Wherein the modified lanthanum hexaboride enhances infrared ray shielding, the composite light stabilizer and the modified cerium oxide synergistically improve the aging resistance, all the components are subjected to substance cooperation and process cooperation, comprehensive improvement of heat insulation, sound insulation and aging resistance of the PVB intermediate film is achieved, and the PVB intermediate film is suitable for the field of high-strength building glass.

The invention discloses a high-interface-stability composite solid electrolyte membrane as well as a preparation method and application thereof. The composite solid electrolyte membrane comprises a gradient aperture three-dimensional porous skeleton formed by sintering inorganic solid electrolyte particles, a polymer electrolyte filled in a pore channel, and a plastic interface stable layer positioned between the electrolyte membrane and an electrode. The preparation method comprises the following steps: preparing a gradient aperture porous framework through a pore-forming agent template method and a tape casting technology, dipping and filling a polymer electrolyte precursor solution in a solution, accelerating in-situ polymerization by adopting electric induction, and performing hot-pressing treatment. The composite solid-state electrolyte membrane has high ionic conductivity, excellent interface compatibility and high mechanical strength, can effectively inhibit the growth of lithium dendrites, can be applied to solid-state batteries such as lithium metal batteries, lithium sulfur batteries and lithium air batteries, and can remarkably prolong the cycle life and improve the safety performance of the batteries, and the preparation process is suitable for large-scale production.

The invention belongs to the technical field of silicon nitride ceramic substrates, and particularly relates to a high-thermal-conductivity and high-breaking-strength silicon nitride substrate and a sintering method and application thereof. In order to simultaneously improve the thermal conductivity and the breaking strength of the existing silicon nitride ceramic substrate and ensure the stability and the consistency of the performance during the production of the silicon nitride substrate, the method comprises the following steps: coating the surface of a silicon nitride ceramic biscuit subjected to tape casting with isolation powder, carrying out nitrogen or air atmosphere glue removal treatment, and then sintering; in the sintering process, the cooling process is optimized, a multi-temperature heat preservation platform is arranged above the liquid phase conversion temperature, grain growth and grain boundary composition of the silicon nitride ceramic are regulated and controlled, grain size distribution of the silicon nitride ceramic is made to be more uniform, the grain boundary structure is made to be more optimized, and the heat conductivity coefficient and breaking strength of the substrate are remarkably improved. Meanwhile, the uniformity of a temperature field in the sintering furnace can be greatly improved through the sintering method, it is ensured that the product can reach the consistent performance standard in different areas, and the stability and reliability of the product are improved.

The invention relates to the technical field of electronic ceramic green bodies, in particular to a glue discharging method of an electronic ceramic green body. Comprising the following steps: step 1, ball-milling raw materials, and carrying out tape casting to obtain a ceramic green body; 2, the ceramic green bodies are subjected to powder coating and stacked into a stack, and laminated green bodies are obtained; 3, in the nitrogen atmosphere, primary glue discharging is conducted on the laminated green body, and a primary glue-discharged green body is obtained; 4, in the nitrogen atmosphere, the primary degummed green body is subjected to secondary degummed, and a secondary degummed green body is obtained; 5, under the nitrogen atmosphere, high-temperature vacuum carbon removal is conducted on the secondary rubber-removed green body, and a high-temperature carbon-removed green body is obtained; 6, under the nitrogen atmosphere, the high-temperature carbon-removed green body is rapidly cooled; and obtaining the electronic ceramic body.

The invention provides a preparation method of a high-thermal-conductivity 99 aluminum oxide ceramic substrate, and belongs to the field of electronic ceramic materials. The method comprises the following steps: homogenizing and grinding a high-purity aluminum-containing compound and a modifier to obtain pretreated powder; mixing the pretreated powder with a carrier gas, and carrying out melt spheroidization to obtain a submicron spherical alumina precursor raw material; homogenizing and defoaming the submicron spherical aluminum oxide precursor raw material, an inorganic sintering aid, a dispersing agent, a binder, a plasticizer and a foam inhibitor in a solvent to obtain ceramic slurry; carrying out tape casting on the ceramic slurry to obtain an aluminum oxide green body; the alumina green body is subjected to rubber discharging, pre-sintering and sintering, and the 99 alumina ceramic substrate is obtained. The submicron spherical alumina powder is prepared through a melt spheroidizing process, the surface of the powder is smooth, particle size distribution is concentrated, grain boundary resistance between the powder is remarkably reduced, sintering densification is promoted, and therefore the technical problems that existing tape casting slurry is poor in stability and high in sintering temperature, and consequently microdefects are caused are solved.

The invention discloses a preparation method of an ABM ceramic substrate with a metal through hole, and particularly relates to the technical field of ceramic substrates, a Si3N4 ceramic substrate is prepared through tape casting and hot pressed sintering, a conical stepped through hole is processed by using ultrafast femtosecond laser, the aperture of the through hole is 100-300 [mu] m, and the smoothness of the wall of the through hole is Rat; 1 [mu] m; performing oxygen plasma activation on the inner wall of the through hole to generate a Si-O active group; sputtering a nano titanium transition layer to enhance metal-ceramic interface bonding; the through holes are filled layer by layer through pulse electrochemical deposition, the current density is controlled, and a compact non-porous structure is achieved; in-Sn-Ag low-temperature active brazing filler metal is used, and a surface copper layer is bonded under the assistance of plasma; a fine circuit is formed through photoetching and micro-electroplating, the line width and the spacing of the circuit are the same, and the line width and the spacing of the circuit are both smaller than 20 microns; etching a micro-channel network on the back surface of the substrate by using ultraviolet laser, and filling heat-conducting silicone grease; and finally, carrying out vacuum annealing for 2 hours in an environment with the temperature of 250 DEG C.

The invention relates to the field of ceramic materials, provides a high-voltage-resistant PTC (Positive Temperature Coefficient) thermal sensitive ceramic material as well as a preparation method and application thereof, and aims to improve the voltage resistance and PTC effect stability of thermal sensitive ceramic. The material is composed of aluminum oxide-coated manganese-doped barium titanate nanorods, hollow-core silicon dioxide microspheres and a glass phase sintering aid, and the electric heating performance and the microstructure stability are optimized by constructing a core-shell structure and a three-dimensional composite system. A hydrothermal method and a sol-gel method are adopted to precisely control a raw material structure, and alcohol dispersion, tape casting and weak oxidizing atmosphere sintering are combined, so that the compactness and consistency of the ceramic are ensured. The material is suitable for high-voltage temperature control elements and over-current protection devices, and is widely applied to the fields of new energy automobile battery pack over-temperature protection, high-voltage power equipment current limiting elements, industrial automatic temperature control switches and the like.

The invention relates to the field of textured low-temperature co-fired ceramic materials, in particular to a textured low-temperature co-fired ceramic material and a preparation method thereof. According to the invention, a part of Al2O3 powder is replaced by flaky alpha-Al2O3, and the flaky alpha-Al2O3 is directionally arranged in the green tape along the tape casting direction through tape casting, so that the arrangement mode can play a role in increasing crack deflection and bridging in the fracture process of the textured low-temperature co-fired ceramic material; the bending strength of the textured low-temperature co-fired ceramic material is improved, and therefore the technical problem that an existing textured low-temperature co-fired ceramic material is poor in mechanical property is solved.

The invention relates to the technical field of ceramic materials, in particular to a preparation method of a zirconium oxide toughened aluminum oxide ceramic substrate, which comprises the following steps: 1, pretreating a powder material; step 2, preparing slurry; step 3, tape casting; step 4, stamping and forming; and 5, sintering. Before the slurry is prepared, the aluminum oxide powder and the zirconium oxide powder are uniformly mixed and then subjected to plasma treatment, so that the surface activity of the mixed powder of the aluminum oxide and the zirconium oxide is improved, the grain structure of the mixed powder of the aluminum oxide and the zirconium oxide is changed, and the toughening effect of the zirconium oxide on the aluminum oxide ceramic substrate is improved.

The invention relates to the technical field of ceramic manufacturing processes, and particularly discloses a preparation method of a 96 aluminum oxide ceramic substrate, which comprises the following steps: slurry preparation: carrying out ball milling treatment on high-purity aluminum oxide powder, a sintering aid, a binder, a plasticizer, an organic solvent and a dispersing agent, and fully mixing to obtain tape casting slurry; forming a green body, coating a carrier film with the tape casting slurry through a tape casting machine with a wet film which is uniform in thickness and flat in surface, and drying the carrier film through a drying box in a partitioned manner to obtain a cured green body; and sintering densification treatment: carrying out glue removal treatment on the green body, and carrying out stepped heating sintering to obtain the 96 aluminum oxide ceramic substrate. According to the 96 aluminum oxide ceramic substrate prepared by the scheme, a large number of uniform crystal cores can be formed, small crystal grains can be dissolved, large crystal grains grow at a constant speed, and the uniformity of the crystal grain size is ensured, so that scattering of phonons on a crystal boundary can be reduced, and a structural foundation is laid for improvement of heat conductivity.

The invention relates to the field of aluminum nitride ceramic substrates, provides a preparation method of a high-thermal conductivity aluminum nitride substrate, and solves the defects of low thermal conductivity and insufficient mechanical strength of an aluminum nitride substrate obtained by adopting a preparation method in the prior art. Comprising the following preparation processes: (1) preparing raw materials and auxiliary materials; (2) mixing the raw materials and the auxiliary materials; (3) tape casting; (4) aging; (5) pre-flattening treatment; (6) sintering; and (7) post-treatment.

The invention relates to the field of high-performance ceramics and bulletproof, in particular to a high-toughness layered boron carbide bulletproof ceramic and a preparation method thereof. The preparation method of the layered boron carbide bulletproof ceramic comprises the following steps: step 1, adding boron carbide powder and a sintering aid into a mixed solvent, then adding a dispersing agent, a binder and a plasticizer, and carrying out mixing and ball milling to obtain ceramic slurry; step 2, preparing the ceramic slurry into a boron carbide ceramic biscuit sheet by adopting a tape casting process; and laminating the boron carbide ceramic biscuit sheets, pressing, and carrying out hot pressed sintering to obtain the layered boron carbide bulletproof ceramic. Through the layered structure design, the controllable preparation of the layered boron carbide bulletproof ceramic is realized, so that the layered boron carbide bulletproof ceramic shows the characteristics of high strength and high toughness under the action force vertical to the layered direction, and the actual application effect of the layered boron carbide bulletproof ceramic is improved. Meanwhile, the layered structure provided by the invention has designability and operability, and the preparation process is simple.

The invention relates to the technical field of polymer functional material processing, and particularly discloses a polyethylene waterproof breathable film using PTFE micro powder as an opening agent and a preparation method of the polyethylene waterproof breathable film. The waterproof breathable film is prepared from the following components in parts by weight: 50-70 parts of linear low-density polyethylene, 10-40 parts of PTFE (Polytetrafluoroethylene) micro powder, 3-8 parts of a modified compatilizer and an auxiliary agent. The preparation method comprises the following steps: S1, activating PTFE micro-powder by a silane coupling agent and coating the PTFE micro-powder with polyethylene wax to obtain modified micro-powder; s2, uniformly mixing all the components; s3, carrying out melt extrusion at 180-210 DEG C through a double-screw extruder, and carrying out tape casting to form a cast sheet; s4, the casting piece is heated to 90-115 DEG C for two-way stretching, and micropores are formed through interface stripping between the PTFE particles and the base body; and S5, carrying out heat setting at 120-130 DEG C, cooling, and rolling to form the film. Through the synergistic effect of the self-made compatilizer and the pretreatment process, the interface anchoring force is enhanced, the problems of powder falling and water leakage of highly-filled PTFE are solved, and meanwhile, high moisture permeability, high hydrostatic pressure resistance and high mechanical property are taken into account.

The invention belongs to the technical field of photovoltaic packaging adhesive films, and particularly relates to an assistant precipitation resistant anti-slip POE packaging adhesive film and a preparation method thereof, and the preparation method comprises the following steps: S1, mixing raw materials, and uniformly stirring to obtain a micro-foaming layer raw material and a skeleton layer raw material; s2, performing melt extrusion, namely performing melt extrusion on the raw materials of the framework layer through a single-screw extruder, and controlling the extrusion temperature and the screw rotating speed to obtain the framework layer; s3, supercritical fluid micro-foaming extrusion is conducted, specifically, raw materials of a micro-foaming layer are subjected to melt extrusion through a co-rotating twin-screw extruder, the extrusion temperature and the screw rotating speed are controlled, supercritical fluid carbon dioxide is introduced in the extrusion process to serve as a foaming agent, then heating foaming is conducted, the adding amount of the foaming agent is 0.5%-2% of the mass of matrix resin, the foaming temperature is 160-200 DEG C, the foaming pressure is 10-20 MPa, and the foaming layer is obtained; a micro-foaming layer is obtained; and S4, tape casting: carrying out three-layer co-extrusion on the micro-foaming layer, the skeleton layer and the micro-foaming layer to form an ABA structural adhesive film, thereby obtaining the POE packaging adhesive film.

The invention relates to the technical field of high-temperature sintering, and particularly discloses a gradient composite kiln furniture based on spinel interface strengthening and a preparation method thereof. Wherein the kiln furniture sequentially comprises a mullite matrix layer, a silicon carbide enhancement layer and a zirconium oxide high-temperature-resistant layer from outside to inside, and the layers are chemically bonded through an in-situ generated MgAlO spinel interface layer. The preparation method comprises the following steps: carrying out layered tape casting on gradient slurry, carrying out isostatic pressing lamination molding, generating an MgSi transition phase at 1380-1420 DEG C through a stepped sintering process, and heating to 1600-1650 DEG C at a specific heating rate to form a continuous spinel interface. According to the kiln furniture, gradient component design cooperates with spinel interface strengthening, the problem of interface stripping caused by thermal expansion mutation of a traditional double-layer structure is solved, and the kiln furniture has excellent thermal shock stability and high-temperature strength retention rate. According to the preparation method, precise construction of the spinel interface is realized through staged reaction control.

The invention discloses an LTCC (Low Temperature Co-Fired Ceramic) green tape as well as a preparation method and application thereof, and the preparation method comprises the following steps: mixing LTCC formula powder and additive phase powder to obtain mixed powder; mixing the mixed powder, a dispersing agent and a solvent, and performing first ball milling treatment to obtain a first ball milling product; adding an adhesive and a plasticizer into the first ball-milling product, and carrying out second ball-milling treatment to obtain a second ball-milling product; filtering the second ball-milled product to obtain ceramic slurry for tape casting; drying the casting ceramic slurry to obtain an LTCC (Low Temperature Co-Fired Ceramic) green tape; wherein the weight ratio of the LTCC formula powder to the additive phase powder is (50-95): (5-50); the LTCC formula powder comprises ceramic powder and glass powder; the additive phase powder is at least one of hexagonal boron nitride, fluorophlogopite sheets, bismuthate-based tungsten bronze and phosphate glass. According to the LTCC green tape prepared by the preparation method disclosed by the invention, the technical problem that the machinability and the thermal conductivity of an LTCC green substrate prepared by an existing LTCC green tape are relatively poor can be solved.

The invention discloses a preparation method of a composite current collector base film based on flame-retardant and aging-resistant modified PP and a composite current collector, the method comprises the following steps: 1) preparation of a modified PP master batch: mixing 100 parts by weight of PP resin, 0.5-1.8 parts by weight of a lubricant and 10-25 parts by weight of a flame-retardant and aging-resistant composite filler, and stirring at 100-135 DEG C for 0.5-2 h to obtain the modified PP master batch; (2) carrying out melt extrusion, tape casting and sheet casting to obtain an intermediate sheet; 3) biaxial stretching; and 4) carrying out heat setting, rolling and slitting to obtain the composite current collector base film. The invention provides the PP base film with excellent flame-retardant and aging-resistant performance and good mechanical strength; furthermore, based on the PP base film, the composite current collector is obtained after copper layers are formed on the two surfaces of the PP base film by adopting a conventional water electroplating process, and the copper layers and the PP base film in the composite current collector have high bonding strength, so that the service life of the composite current collector can be effectively prolonged.

The invention discloses a polyimide composite film with ultrahigh transmittance for flexible display. Belongs to the technical field of polyimide composite materials. A transparent polyimide film product doped with Al2O3 filler serves as a substrate, and silicon dioxide anti-reflection films are plated on the two faces of the transparent polyimide film product. The transparent polyimide film substrate is prepared by the following steps: uniformly polymerizing a diamine monomer containing a plurality of large-volume side groups and 6FDA, doping modified Al2O3 microspheres with different mass fractions, and casting on a treated glass substrate by a tape casting method; the silicon dioxide anti-reflection film is a SiO2-PI-SiO2 sandwich structure formed by preparing sol through a Stober method, aging the sol and uniformly plating the sol on a polyimide film substrate through a dip-coating method. The average transmittance of the polyimide composite film with the SiO2 anti-reflection films on the two sides and doped with the modified Al2O3 microspheres in the visible light range exceeds 97%, and meanwhile the polyimide composite film has excellent thermal performance and mechanical performance. The method can be used for large-scale production, and a new high-quality and sustainable substrate material selection is provided for the flexible display industry.

The invention discloses a preparation method of a high-strength aluminum oxide ceramic substrate, which comprises the following steps: firstly, modifying aluminum oxide powder by a liquid phase method, and coating a layer of nano magnesium oxide on the surface of the aluminum oxide powder; then carrying out ball milling treatment on the modified powder, rare earth metal oxide, metal oxide, an organic solvent, a binder, a plasticizer and a dispersing agent together, then carrying out defoaming, tape casting, drying and laminated hot pressing to obtain a ceramic green body, and finally carrying out sintering molding in an air atmosphere to obtain the ceramic. The nano magnesium oxide active coating layer constructed in situ and the added exogenous sintering aid act together, so that uniform growth of isometric crystals is promoted, development of a small amount of dominant oriented grains is directionally induced, a composite enhanced microstructure is formed, atomic scale super-uniform distribution and optimal interface combination of the nano magnesium oxide and the exogenous sintering aid are realized, and the nano magnesium oxide / exogenous sintering aid composite material is prepared. The bending strength of the obtained alumina ceramic can reach up to 881 MPa.

A high-conductivity high-temperature-resistant ceramic electrode with a multilayer gradient composite structure sequentially comprises a bottom supporting layer, a middle transition layer and a surface conductive layer from bottom to top, the bottom supporting layer is a porous supporting layer, the middle transition layer is doped with metal nanowires in a gradient mode to form a three-dimensional conductive network, the surface conductive layer is made of high-conductivity ceramic, and the surface conductive layer is made of high-conductivity ceramic. The preparation method of the high-conductivity high-temperature-resistant ceramic electrode comprises the following steps: (1) tape casting; and (2) hot pressed sintering. The multi-layer gradient composite structure design is adopted, the surface conductive layer is made of high-conductivity ceramic and reduces bulk resistance, the middle transition layer is doped with metal nanowires in a gradient mode to form a three-dimensional conductive network, the bottom supporting layer is a high-strength porous ceramic matrix, the mechanical performance is improved, and thermal stress is relieved; interlayer seamless combination is achieved through the tape casting and hot pressing sintering integrated forming technology, the interface defect of a traditional lamination technology is avoided, and the industrial problem that it is difficult to collaboratively optimize the conductivity, strength and high-temperature resistance of conductive ceramic is solved.

The present invention discloses a debinding process for silicon nitride ceramic green bodies, which includes: (1) After the silicon nitride raw powder is formed by tape casting, a silicon nitride ceramic green body is made. The silicon nitride ceramic green body is placed in a crucible, and a layer of boron nitride powder is applied on the surface of the green body; (2) Debinding is carried out in stages in a muffle furnace; The debinding of the silicon nitride ceramic green body is realized, the generation of silicon dioxide in the debinding process is reduced, and the quality of batch production of silicon nitride ceramic substrates is improved.

The invention discloses a manufacturing method of a grinding wheel for a high-uniformity and easy-to-sharpen grinding single crystal diamond cutter, and belongs to the field of superhard materials and products in machining, the manufacturing method mainly comprises the steps of wet mixing, tape casting, laser cutting, lamination, matrix surface treatment, integrated sintering, size processing, sharpening and the like, and finally the grinding wheel with the total thickness of an abrasive layer being 7-15 mm is formed. The grinding wheel layer is formed by intersecting and laminating a piece a and a piece b, the height of diamonds at the junction of the piece a and the piece b tends to be consistent, the diamond exposure height and smoothness are better compared with direct feeding sintering, meanwhile, the piece a can be designed to be of a porous structure through proper binder selection, and therefore the dressing efficiency is further improved, and the dressing effect is better. And higher processing quality and efficiency of the diamond cutter are indirectly improved.

The invention relates to a preparation method of a silicon nitride ceramic substrate and the silicon nitride ceramic substrate. The preparation method of the silicon nitride ceramic substrate comprises the following steps: preparing slurry by using silicon-based powder, a sintering aid and a dispersion medium; wherein the sintering aid comprises magnesium oxide sol, and the sintering aid further comprises at least one of rare earth oxide sol; carrying out tape casting on the slurry to obtain a green sheet; and sintering the green blank sheet in a nitrogen atmosphere. According to the preparation method of the silicon nitride ceramic substrate, the slurry is prepared by using the sintering aid comprising the magnesium oxide sol and the rare earth oxide sol, the silicon-based powder and the dispersion medium, silicon nitride powder and sintering aid particles in the slurry are relatively uniformly dispersed and are not easy to agglomerate, and a relatively uniformly dispersed green sheet can be obtained through tape casting; therefore, the strength consistency of different areas of the prepared silicon nitride ceramic substrate is relatively good, and the discreteness is relatively small.

The invention relates to the technical field of silicon nitride ceramic chips, in particular to a reactive sintering silicon nitride ceramic chip processing method which comprises the following steps: S1, adding spherical boron nitride powder and a dispersing agent into a solvent, and mixing to obtain a spherical boron nitride solution; s2, mixing the spherical boron nitride solution and the yttrium solution to obtain a mixed solution; s3, a sintering aid, silicon powder and the mixed solution are put into a ball mill for pulping, and slurry is obtained; s4, the slurry is subjected to tape casting through a tape casting machine, and a tape casting green body is prepared; s5, the tape-casting green body is placed on a powder coating machine for powder coating, and the tape-casting green body coated with the powder is obtained; s6, the green bodies coated with the powder are laminated and then put into a hot air glue discharging furnace to be subjected to glue discharging treatment, and laminated green bodies are obtained; and S7, sintering the laminated green body to obtain the silicon nitride ceramic chip. The yttrium-containing substance is locally coated with the spherical boron nitride powder, the invention provides a method for processing the reactive sintering silicon nitride ceramic chip, and the prepared silicon nitride ceramic chip is compact in structure and excellent in bending strength.

The invention discloses a low-temperature sintered microwave dielectric ceramic material and a preparation method thereof, and belongs to the technical field of electronic materials. The composite material comprises the following raw materials: CaCO3, SrCO3, Bi2O3 and B2O3. The preparation method comprises the following steps: burdening and weighing according to a stoichiometric ratio CaxSr1-xBi2B2O7 (x is more than 0.1 and less than 0.9), then carrying out ball milling and mixing, pre-sintering to obtain pre-sintered ceramic powder, adding an organic material to prepare stable slurry, carrying out tape casting to obtain a green body, and sintering to obtain the low-temperature sintered microwave dielectric ceramic material. The sintering temperature of the ceramic material is 700-800 DEG C, the dielectric constant range is 4-8, the loss value is less than 0.00002, and the ceramic material has low dielectric constant and ultrahigh quality factor. The problems that an existing low-temperature sintering microwave dielectric ceramic material is high in water absorption and high in material cost are solved. The microwave ceramic dielectric is applied to the technical field of electronic components requiring low dielectric constant and low loss value microwave ceramic dielectric.

The invention provides an LTCC raw material belt with a high thermal expansion coefficient, an LTCC substrate and a preparation method of the LTCC substrate, the LTCC raw material belt with a smooth surface and a uniform thickness is obtained through tape casting by adjusting the proportion of silicon dioxide ceramic powder, MgTiO3 ceramic, SrTiO3 ceramic, Li2MgSiO4 ceramic, BCBS, ZABS and LASP microcrystalline glass powder, the LTCC raw material belt is sintered in a nitrogen furnace at 880-940 DEG C for 1-3 h, and the LTCC raw material belt can be co-fired with low-cost copper electrode slurry to be flat and tightly attached to the low-cost copper electrode slurry. The LTCC substrate with the thermal expansion coefficient larger than 11 ppm / DEG C is prepared, under the test frequency of 5 GHz, the dielectric constant of the LTCC substrate ranges from 5.1 to 6.1, the dielectric loss ranges from 0.0025 to 0.004, the bending strength ranges from 170 MPa to 230 MPa, the thermal expansion coefficient at the temperature ranging from 30 DEG C to 400 DEG C ranges from 11.0 ppm / DEG C to 13.0 ppm / DEG C, and acid resistance is good.

The invention relates to the technical field of ceramic materials, in particular to a preparation method of a low-temperature sintered high-thermal-conductivity 99 ceramic aluminum oxide ceramic substrate, which comprises the following steps of: 1, preparing slurry; step 2, tape casting; step 3, stamping and forming; 4, performing warm isostatic pressing treatment; step 5, performing main firing to obtain porcelain; and 6, inspecting a finished product. By regulating the particle size of the alumina powder, adopting the specific sintering aid of the solid solution and the liquid phase forming agent, introducing trace La2O3 into the system and combining low-temperature co-firing, the problem that the 99 ceramic alumina ceramic substrate is easy to crack in the processing process is improved while the sintering temperature of the 99 ceramic alumina ceramic substrate is remarkably reduced.

The invention provides an LTCC green tape, an LTCC substrate, a copper co-fired LTCC substrate and a preparation method thereof, and the preparation method of the LTCC green tape comprises the following steps: S1, putting weighed powder into a ball milling tank, adding a solvent and a dispersant, carrying out ball milling and mixing, then adding a binder and a plasticizer, and continuously carrying out ball milling to obtain tape casting slurry; the powder material comprises the following components in percentage by mass: 40wt% of aluminum oxide ceramic powder, 55wt%-60wt% of BMCS glass powder and 0-5wt% of CMAS glass powder; and S2, carrying out vacuum defoaming on the tape casting slurry, and carrying out tape casting to obtain the LTCC green tape. The bending strength of the LTCC substrate formed by the LTCC green tape provided by the invention is improved on the premise of ensuring excellent dielectric properties, and the flat copper co-fired LTCC substrate is formed by matching and co-firing the LTCC green tape and the copper paste in a nitrogen atmosphere, so that the cost is greatly reduced.