803results about How to "High thermal conductivity" patented technology

The invention belongs to the technical field of aviation accessory production, and particularly relates to a welding machining system and method for assembling a combined aviation aluminum shell. The inner supporting plate bending assembly and the inner supporting plate punch forming assembly are jointly used for conducting punching machining on the upper side and the lower side of the joint, a protruding plate which is folded inwards is formed in the punching forming process, and the inner supporting plate bending assembly is used for bending the protruding plate to form an inner supporting plate; the inner side and the outer side of the joint can be welded at the same time through the joint welding assembly; by means of the inner supporting plate punching assembly, an installation hole facilitating installation of a threading plate through a bolt can be formed and machined in the inner supporting plate, in this way, main components of the combined type aviation aluminum shell can be reliably clamped, and reliable anti-deformation supporting is provided in the trepanning and welding process; two sides of the weld are uniformly heated, and internal stress is relatively balanced, so that deformation is reduced, and the overall quality of the weld is improved.

The invention relates to a composite phase-change film based on liquid metal and PBO fiber and a preparation method thereof, and belongs to the technical field of phase-change material preparation, and the preparation method comprises the following steps: the composite phase-change film comprises a poly (p-phenylbenzobisoxazole) fiber (PBO) base material, a phase-change material and a heat-conducting filler, the phase-change material is composed of phase-change microcapsules (PM) which are prepared by taking polyurethane (PU) as a wall material and organic solid-liquid phase-change materials (OPCMs) as a core material through a Pickering emulsion polymerization method. The prepared PM has a core-shell structure, and leakage of OPCMs is effectively prevented. The PM and the PBO fiber network are combined, so that the dual packaging of the OPCMs is realized, and the leakage of the OPCMs is further prevented. Meanwhile, dispersion and interaction of the OPCMs in a PBO matrix are optimized, and formation of a network structure with a limited domain is promoted. The composite phase change film prepared by the invention has relatively high mechanical properties, remarkable heat conductivity, excellent and stable flexibility and excellent heat storage capacity.

The invention relates to the technical field of powder metallurgy, in particular to a tungsten-copper alloy preparation method and a tungsten-copper alloy. The preparation method of the tungsten-copper alloy comprises the following steps: mixing double-scale compound tungsten powder containing nanocrystals and ultra-fine grains or double-scale compound tungsten-tungsten oxide powder containing nanocrystals and ultra-fine grains with copper oxide powder to obtain precursor slurry; drying the precursor slurry to obtain precursor composite powder; the precursor composite powder is subjected to segmented reduction, tungsten-copper composite powder is obtained, and tungsten crystal grains in the tungsten-copper composite powder are distributed in a double-scale mode of nanocrystals and ultra-fine crystals; and the tungsten-copper composite powder is prepared into a blank and sintered, and the tungsten-copper alloy is obtained. The heat conductivity and density of the tungsten-copper alloy can be improved.

The invention discloses a high-performance polyether-ether-ketone plate and a preparation method thereof, and belongs to the technical field of semiconductor manufacturing. The high-performance polyether-ether-ketone plate comprises the following components in parts by weight: 80-90 parts of polyether-ether-ketone, 1-3 parts of carbon nanotubes, 1-3 parts of graphene nanosheets, 2-5 parts of conductive tin oxide micro powder, 3-5 parts of polytetrafluoroethylene micro powder and 0.5-1 part of a silane coupling agent. The PEEK composite material provided by the invention has excellent mechanical, conductive, heat management, corrosion resistance and antistatic properties, and is suitable for severe environments such as high temperature, corrosion and fatigue resistance.

The invention relates to the technical field of coating preparation, and particularly discloses a multifunctional composite filler modified water-based coating and a preparation method thereof.The water-based coating is prepared from, by weight, 80-100 parts of modified core-shell acrylic acid dispersoid, 5-7 parts of multifunctional composite filler, 0.5-1 part of defoaming agent, 0.5-1 part of wetting agent, 2-5 parts of thickening agent, 1-2 parts of coalescing agent and 25-35 parts of deionized water. The water-based paint provided by the invention is modified by adding a proper amount of multifunctional composite filler, the performance is excellent, the stability is good, the components in the water-based paint have good compatibility by optimizing the preparation process conditions of the water-based paint, and the preparation method is simple to operate and suitable for industrial production.

The embodiment of the invention provides a gold-silver alloy bump structure, a preparation method and a semiconductor device, and the preparation method comprises the steps: providing a semiconductor device, and forming a seed layer on the surface of the semiconductor device; a first gold-silver alloy bump is formed on the seed layer through an electroplating technology, the gold content in the formed first gold-silver alloy bump is larger than 45%, and the thickness of the first gold-silver alloy bump ranges from 0.2 micrometer to 5 micrometers; and electroplating the first gold-silver alloy bump by using the same electroplating liquid to form a second gold-silver alloy bump, wherein the gold content in the formed second gold-silver alloy bump is less than 30%, and the thickness range of the second gold-silver alloy bump is 3-20 [mu] m. The first gold-silver alloy bump with high gold content improves the binding force between the bottom of the gold-silver alloy bump structure and the seed layer of the semiconductor device, and improves the reliability of the semiconductor device. The second gold-silver alloy bump with low gold content can avoid pure gold bumps on the surface of the gold-silver alloy bump structure, the hardness and morphology of the gold-silver alloy bump structure are controlled, and subsequent packaging is ensured.

The invention discloses a phase change fiber membrane with a composite core-sheath structure and a preparation method and application thereof.The method comprises the steps that polyacrylonitrile is dissolved in N 'N-dimethylformamide and stirred to be completely dissolved, then hydroxylated boron nitride is added, the hydroxylated boron nitride is evenly dispersed through ultrasonic treatment, and a sheath spinning precursor solution is prepared; dissolving polyethylene glycol in N 'N-dimethylformamide, stirring to melt the polyethylene glycol, and taking the polyethylene glycol as a core layer spinning precursor solution; preparing a phase change fiber membrane with a core-sheath structure from the sheath spinning precursor solution and the core spinning precursor solution through a coaxial electrostatic spinning process; and placing the phase change fiber membrane with the core-sheath structure in an ethanol dispersion liquid of hydroxylated boron nitride, carrying out ultrasonic dip-coating, and then carrying out cold pressing treatment to prepare the phase change fiber membrane with the composite core-sheath structure. The obtained composite core-sheath structure phase change fiber membrane has good latent heat property, thermal conductivity and flexibility, and meanwhile, leakage of the phase change material is prevented through the core-sheath structure.

The invention belongs to the technical field of semiconductor devices, and discloses a diamond-based CMOS (complementary metal oxide semiconductor) inverter and a preparation method thereof. The diamond-based CMOS inverter comprises a diamond substrate, a monocrystalline diamond film, a hydrogen terminal region, a mesa isolation region, an n-type oxide semiconductor layer, a first source electrode, a first drain electrode, a second source electrode, a second drain electrode, a first gate dielectric layer, a first gate electrode, a second gate dielectric layer and a second gate electrode. The first drain electrode and the second drain electrode are in metal interconnection; the first gate electrode and the second gate electrode are metal-interconnected. The diamond-based CMOS phase inverter is prepared by combining the p-type hydrogen terminal diamond and the n-type oxide semiconductor, so that the technical problem that an n-type MOS device is difficult to realize by the diamond at present is effectively avoided, respective advantages of the diamond and the n-type oxide semiconductor are fully exerted, and the high-performance diamond-based monolithic integrated CMOS phase inverter is realized.

The invention discloses a low-thermal-conductivity and high-temperature-resistant silicon oxide aerogel heat insulation felt and a preparation method thereof, and the prepared silicon oxide aerogel felt has the characteristics of temperature resistance of 1100 DEG C, good flexibility, excellent high-temperature heat insulation performance and convenience in construction, and has wide application prospects in the fields of aerospace, industrial kilns and the like.

The invention discloses a surface plasmon-based 3 [mu] m waveband solid femtosecond laser, comprising: a fiber laser pumping source for emitting a laser beam; the resonant cavity comprises an input mirror group and a surface plasmon light modulation element; the laser beam can be input into the surface plasmon light modulation element through the input lens group; and an output mirror; wherein the laser beam is reflected to the input mirror group through the surface plasmon light modulation element, so that the laser beam can be output through the output mirror. The laser prepared by the invention has the advantages of high damage threshold, strong nonlinear modulation characteristic, high stability and the like, and effectively breaks through the barrier in the prior art.

The invention discloses an integrated preparation method of a large-thickness high-density electrical insulation-corrosion-resistant ceramic coating on the surface of a heat dissipation substrate for a high-power device, and relates to the technical field of surface treatment of aluminum alloys and composite materials thereof. The method comprises the following steps: placing a pretreated substrate as an anode and a stainless steel plate as a cathode in a basic arc suppression type electrolyte, and performing low-temperature soft plasma electrolytic oxidation on the surface of the pretreated substrate by using an asymmetric bipolar pulse micro-arc oxidation technology to grow a large-thickness high-density ceramic layer in situ; specifically, low-temperature soft spark discharge is induced by inserting additional negative pulse voltage, the plasma temperature and energy are stabilized, spark discharge is uniform, and the density is increased by an order of magnitude, so that continuous bombardment with no damage to the surface flatness as the plasma intensity upper limit is carried out on a passive film on the surface of a substrate; and the defects such as pores and cracks are continuously healed and repaired, and the densification of the coating is promoted, so that the aluminum oxide coating with large thickness, high density, high electrical insulation and corrosion resistance is obtained.

The invention relates to a packaging electrode, a manufacturing method thereof and a semiconductor packaging device. The manufacturing method comprises the steps that a diamond composite metal base layer is prepared, a first alloy layer and a second alloy layer are formed on the upper side surface and the lower side surface of the diamond composite metal base layer respectively, and a conductive flange is formed on the side wall of the diamond composite metal base layer; the diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are of an integrated structure. The surfaces, deviating from the diamond composite metal base layer, of the first alloy layer and the second alloy layer are machining surfaces and are used for being in direct contact with a chip; the flange welding surface of the conductive flange is free of diamond composition. According to the invention, the forming quality and performance of the large-size packaging electrode can be improved, so that the packaging reliability of the semiconductor packaging device can be effectively improved.

The invention discloses a preparation method of a low-density high-thermal-conductivity copper-based graphite heat sink material, which comprises the following steps of: 1, selecting one or more than two copper alloy powder of CuZr powder, CuCr powder and CuCrZr powder as matrix powder, and mechanically ball-milling and mixing the matrix powder with graphite powder; 2, sintering the mixed powder to obtain a sintered body; and 3, carrying out aging heat treatment on the sintered body to obtain the low-density high-thermal-conductivity copper-based graphite heat sink material. The reinforced phase raw material graphite powder is added into the copper alloy powder to be mixed and sintered, so that a carbide ceramic phase is generated in situ, a ceramic phase transition layer is formed, the interface bonding capacity between a copper matrix and graphite is improved, the copper alloy powder with different components and sizes is used at the same time, a heterostructure matrix structure is formed, and the performance of the composite material is improved. The strength and plasticity of the copper-based graphite heat sink material are improved, so that the copper-based graphite heat sink material has excellent mechanical properties and thermal conductivity, and is simple in process, low in cost and suitable for the field of heat sink materials.

The invention provides low-moisture-absorption and high-thermal-conductivity electrical-grade magnesium oxide and a preparation method thereof.The preparation method comprises the steps that silicon powder and silica sol are mixed to serve as coating slurry; carrying out coating treatment on the fused magnesium oxide by using the coating slurry, and then drying and screening to prepare silicon-coated fused magnesium oxide powder; the preparation method comprises the following steps: performing multi-stage preheating treatment and nitriding treatment on silicon-coated fused magnesium oxide powder in a nitrogen atmosphere, so that silicon powder on the surface of magnesium oxide is nitrided to form molten silicon nitride, and finally cooling and sizing to obtain high-temperature electrical-grade magnesium oxide powder with a spherical core-shell structure. The electrical grade magnesium oxide powder can resist high temperature and moisture, more importantly, the heat conduction performance of magnesium oxide is ensured, and the flowability and filling efficiency of the powder are improved.

The invention discloses a rubber composite material for a high-performance tire and a preparation method of the rubber composite material. The rubber composite material is prepared from the following raw materials in parts by weight: 30-50 parts of natural rubber, 10-15 parts of butadiene rubber, 25-40 parts of butadiene styrene rubber, 10-20 parts of carbon black, 10-30 parts of composite filler, 2-8 parts of aromatic hydrocarbon oil, 2-5 parts of an anti-aging agent, 1-5 parts of a vulcanizing agent, 1-5 parts of a vulcanization accelerator and 1-3 parts of stearic acid. The prepared rubber composite material has excellent mechanical properties, enhanced tear resistance and overall strength, the outstanding wear resistance enables a tire to adapt to various road conditions, the heat dissipation performance is optimized, thermo-oxidative aging is reduced, the service life is prolonged, the hardness and rigidity are improved, the wear resistance is enhanced, the rolling resistance is reduced, and the fuel efficiency is improved; the improved dynamic balance performance and anti-flowability improve the driving safety, are suitable for wear-resistant tires used for a long time and vehicles with special road conditions, and provide high-quality choices for severe environments.

The embodiment of the invention provides a preparation method of a tungsten-copper alloy and the tungsten-copper alloy, and relates to the technical field of alloy preparation.The method comprises the steps that superfine tungsten oxide powder, tungsten salt, copper salt and a polymer additive are added into deionized water to be evenly mixed, and a precursor mixed solution is obtained; carrying out spray granulation on the precursor mixed solution by adopting a spray dryer to obtain spherical tungsten-copper precursor composite powder; roasting the spherical tungsten-copper precursor composite powder to obtain tungsten-copper oxide composite powder, and carrying out segmented reduction on the tungsten-copper oxide composite powder to obtain tungsten-copper composite powder with tungsten grains having a nanocrystalline / ultra-fine grain bimodal distribution characteristic; and the tungsten-copper composite powder is pressed to obtain an alloy blank, the alloy blank is sintered, and the tungsten-copper alloy is prepared. According to the double-peak distribution tungsten-copper composite powder, full densification of the alloy can be promoted through coupling rearrangement of large and small tungsten particles in the sintering process, and the compactness, the heat conductivity and the electric conductivity of the tungsten-copper alloy can be improved.

The invention discloses a mesophase pitch carbon matrix modified high-thermal-conductivity C / SiC composite material and a preparation method thereof, the material is subjected to high-thermal-conductivity matrix modification through mesophase pitch melt impregnation, in-situ mesophase inversion and in-situ carbonization, and mesophase pitch carbon fibers are combined as a reinforcement, so that the high-thermal-conductivity C / SiC composite material is obtained. The mesophase pitch carbon matrix modified high-thermal-conductivity C / SiC composite material is obtained by densifying a silicon carbide matrix by adopting a polycarbosilane melt impregnation and in-situ cracking process, has excellent mechanical and high-thermal-conductivity properties, can be widely applied to the front edge, the end head and other parts of a hypersonic aircraft, and can effectively improve the use temperature and the service environment of the material. Meanwhile, the preparation process is simple, the equipment use requirement is low, and the material preparation process period and cost can be correspondingly reduced.

The invention provides a preparation method of a coated particle dispersion fuel, which comprises the following steps: mixing silicon carbide powder and a binder according to a preset mass ratio, banburying and granulating to obtain a silicon carbide matrix feed; printing a silicon carbide shell green body by using powder extrusion printing equipment and the silicon carbide matrix feed; degreasing the silicon carbide shell green body by using a degreasing solvent to obtain a silicon carbide shell brown blank; a cavity of the silicon carbide shell brown blank is filled with cladding fuel particles, and pores of the cladding fuel particles are filled with silicon carbide powder; and filling the filled silicon carbide shell brown blank into a chemical vapor infiltration device, generating silicon carbide by the introduced methyl trichlorosilane, filling a gap between the silicon carbide powder and the silicon carbide shell green blank with the silicon carbide, and obtaining the coated particle dispersion fuel after the chemical vapor infiltration is completed. By adopting powder extrusion printing and chemical vapor infiltration methods, the problems that the irradiation swelling resistance of existing coated particle dispersion fuel is reduced, the heat conductivity is low, and the loading capacity of coated fuel particles is limited are solved.

The invention relates to the field of preparation of silicon carbide micro powder, in particular to a preparation process of high-purity silicon carbide micro powder, which comprises the following steps: mixing silicon powder and carbon powder in proportion; the mixed raw materials generate silicon carbide in the heating chamber; cooling the silicon carbide; preliminarily grinding to obtain silicon carbide particles; purifying the silicon carbide particles; drying equipment is used for removing moisture in the silicon carbide particles, and the silicon carbide particles are finely ground into silicon carbide micro powder; judging the production quality according to the purity of the silicon carbide micro powder; and determining a corresponding mode for improving the purity of the silicon carbide according to the production quality. According to the method, the controllability of the purity of the prepared silicon carbide micro powder is improved through free carbon removal and acid pickling, and the production efficiency is improved.

The invention discloses low-lithium high-strength transparent microcrystalline glass and a preparation method thereof. The low-lithium high-strength transparent microcrystalline glass is prepared from the following raw materials: 7wt%-15wt% of Li2O, 2wt%-12wt% of Al2O3, 60wt%-78wt% of SiO2, 1wt%-4wt% of ZrO2, 1wt%-5wt% of P2O5, 0-1wt% of Na2O and 0-3wt% of K2O. The preparation method comprises the following steps: mixing the raw materials, melting, annealing and crystallizing to obtain the low-lithium high-strength transparent glass ceramic which is a glass ceramic product with high mechanical strength, high transmittance, low haze, low dielectric loss and high thermal conductivity, can meet the requirements of mobile phone cover plate glass on the glass ceramic, reduces the cost, has a very good market value, and is suitable for popularization and application. The high-strength transparent microcrystalline glass can be applied to a front cover and / or rear cover protection component in a cover plate material for a touch display product.

The invention relates to the technical field of heat-resistant materials, in particular to a heat-resistant polyethylene material and a preparation method thereof, and the heat-resistant polyethylene material comprises the following raw materials: ultra-high molecular weight polyethylene, zirconium oxide-zinc aluminate spinel (ZrO2-ZnAl2O4), modified graphdiyne, an antioxidant, a heat stabilizer, a plasticizer, a flame retardant and an anti-ultraviolet agent. The ultrahigh molecular weight polyethylene, the ZrO2-ZnAl2O4 and the modified graphdiyne play a role through a synergistic effect, a polyethylene molecular chain forms a firm three-dimensional network structure in a high-temperature radiation process, and a stable matrix supporting effect is provided; the excellent chemical stability and oxidation resistance of ZrO2-ZnAl2O4 in a high-temperature environment effectively inhibit the thermal degradation reaction of polyethylene, the service life of the material is prolonged, the modified graphdiyne is beneficial to rapid heat transmission, the thermal stability of the material is improved, meanwhile, the layered structure of the material has good lubricating performance, and the service life of the material is prolonged. The modified graphdiyne and the ZrO2-ZnAl2O4 are combined to avoid heat accumulation and material aging caused by the friction effect, and the ultrahigh molecular weight crosslinked polyethylene, the ZrO2-ZnAl2O4 and the modified graphdiyne form a multi-layer protection system to jointly improve the heat stability of the material.

The invention discloses an infrared radiation heat dissipation composite material as well as a preparation method, a coating and application thereof. The preparation method of the infrared radiation heat dissipation composite material comprises the following steps: firstly, dispersing soluble rare earth metal salt and graphene oxide in deionized water, adjusting the pH value, heating, and carrying out a hydrothermal reaction; and washing and drying the reaction product, and calcining in a protective atmosphere. A hydrothermal in-situ loading method is adopted, carrier absorption of reduced graphene oxide is promoted by utilizing a rich electronic structure of the synthesized rare-earth metal oxide, and the rare-earth metal oxide is uniformly loaded on the surface of the reduced graphene oxide due to a porous structure constructed between the reduced graphene oxide, so that the surface of the reduced graphene oxide is uniformly loaded on the surface of the rare-earth metal oxide. Incident light is subjected to multiple times of diffuse reflection and absorption, and the emissivity is promoted to be improved. The prepared composite material is added into a high-molecular polymer to form an infrared radiation heat dissipation coating, and the infrared radiation heat dissipation coating not only has full-wave-band high emissivity, but also has high heat conductivity.

The invention discloses a ceramic heat sink material and a preparation method thereof, and the preparation method comprises the following steps: S1, taking a Si-Al alloy ingot, porous C-Si3N4 and a sintering aid as raw materials, and carrying out pre-sintering to obtain a compound; and S2, carrying out spark plasma sintering treatment on the compound in a vacuum atmosphere to obtain the ceramic heat sink material, according to the preparation method, the Si-Al alloy ingot and the porous C-Si3N4 are taken as raw materials, the Si-Al alloy ingot permeates into the porous C-Si3N4 material under the heating melting condition, the composite AlN-SiC ceramic material which is uniform in phase distribution and compact is formed in situ in combination with the sintering aid, the obtained ceramic heat sink material is large in crystal grain and small in number of crystal boundaries, scattering of phonons is reduced during heat conduction, and the heat sink material has the advantages of being high in heat sink efficiency and good in heat sink performance. The heat conductivity is improved; meanwhile, the prepared ceramic heat sink material is high in grain density and uniformity, low in oxygen content in crystal lattices and moderate in impurity-phase silicon content, so that the heat conductivity is high, and the ceramic heat sink material is suitable for being used as a heat sink ceramic substrate.

The invention relates to ceramic slurry, a ceramic substrate and a preparation method thereof, and belongs to the technical field of ceramic materials. The ceramic slurry provided by the invention comprises the following components in parts by weight: 85-90 parts of aluminum oxide powder, 6-15 parts of heat-conducting powder, 1-7 parts of a plasticizer, 3-9 parts of a sintering aid, 2-6 parts of a dispersing agent, 2-5 parts of a viscosity modifier and 10-15 parts of a solvent, the heat-conducting powder comprises aluminum nitride, zirconium oxide and beryllium oxide; the sintering aid is prepared from TiN, ZrO2 and CaC2. According to the invention, the heat-conducting powder and the sintering aid are added into the ceramic slurry, and are reasonably proportioned with other components, so that the high-heat-conductivity and high-strength ceramic substrate is obtained.

The invention relates to the technical field of high-temperature heat storage, in particular to a foundation structure for supporting a high-temperature fused salt storage tank. The foundation structure comprises a concrete foundation layer, a ceramsite layer, a foam glass layer, a calcium silicate layer and a sand cushion layer which are sequentially stacked upwards from the ground. The sand cushion layer is used for making contact with the tank bottom of the high-temperature fused salt storage tank, receiving heat from the tank bottom of the high-temperature fused salt storage tank and conducting the heat downwards. The calcium silicate layer can keep the temperature of the foam glass layer to be lower than the temperature-resistant upper limit value when receiving heat transferred from the sand cushion layer. According to the foundation structure, the heat loss of the foundation structure in the ground direction can be reduced while the cost is not obviously increased, meanwhile, differential settlement is avoided, and the foundation structure is suitable for molten salt materials with the use temperature reaching 650 DEG C or above.

The utility model provides a high-reliability SIC-MOSFET terminal structure, belonging to the technical field of semiconductor devices, the high-reliability SIC-MOSFET terminal structure comprises a source electrode and a drain electrode, the source electrode is the input end of an MOSFET and is used for current in a circuit to enter, and the drain electrode is the output end of the MOSFET and is used for exporting current; a groove and a grating are arranged between the source electrode and the drain electrode, the structure among the source electrode, the drain electrode, the groove and the grating is a FinFET structure, the source electrode and the drain electrode are fixedly connected through the middle groove and the grating, the groove is fixedly connected with the grating, the groove comprises a first groove and a second groove, and the first groove and the second groove are communicated with each other. The first groove is fixedly connected with the source electrode. The problem that an existing SIC-MOSFET0 is prone to being broken down under the conditions of high voltage and high current can be solved.

The invention belongs to the technical field of electronic packaging materials, and particularly relates to an epoxy resin composite material with a low thermal expansion coefficient, a cured product and application. The epoxy resin composite material with low thermal expansion coefficient, high thermal conductivity and good flowability is prepared by compounding the negative thermal expansion filler, the thermal conductive filler, the epoxy resin and the curing agent through the synergistic effect of the components, so that the epoxy resin composite material has good flowability and filling property during plastic packaging; the packaging operation can be better carried out, the packaging effect is improved, the working stability of electronic components is effectively improved, the working life is prolonged, and the packaging material has wide application prospects in the field of electronic packaging materials.

The invention discloses a composite sheet for chip bonding and a preparation method thereof, and belongs to the technical field of electronic packaging, the product is compounded by a copper sheet and a silver-containing pre-sintered layer which are arranged in a specific size and composition, the heat conductivity and the electric conductivity of the material are high, and lead bonding only needs to be directly realized on the surface of the copper sheet during use, so that the production cost is reduced, and the production efficiency is improved. Chip bonding can be completed by connecting the silver-containing pre-sintered layer with the chip, additional operation is not needed, use is convenient, and it is guaranteed that the chip cannot be damaged.

The invention provides a black aluminum oxide ceramic material as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, manganese oxide, chromium oxide and a solvent to obtain an aluminum oxide ceramic mixed solution; (2) mixing the alumina ceramic mixed solution with a binder, and grinding to obtain alumina ceramic powder; and (3) carrying out cold pressing treatment on the aluminum oxide ceramic powder, and carrying out vacuum pressureless sintering treatment to obtain the black aluminum oxide ceramic material. The black aluminum oxide ceramic material prepared by the method disclosed by the invention is relatively small in crystal grain, relatively small in pore and relatively high in density, and has relatively high compactness and thermal conductivity.

The invention relates to the technical field of heat conduction and heat dissipation materials, and particularly discloses an efficient heat dissipation graphite material for LED large-screen display and a preparation method of the efficient heat dissipation graphite material. The efficient heat dissipation graphite material for LED large screen display comprises a graphene layer and a thin film coating, and the graphene layer comprises the following raw materials: 50-60 parts of graphite powder, 1-2 parts of nano silver, 25-30 parts of modified nano carbon fibers, 10-15 parts of modified sodium alginate, 3-6 parts of sodium carboxymethyl cellulose, 5-8 parts of a heat conduction agent and 3-5 parts of a plasticizer. The graphite material prepared by the invention has relatively good mechanical properties, heat dissipation performance and corrosion resistance, can meet high requirements of LED large screen display on heat dissipation performance, is widely applied to a heat dissipation system of LED large screen display, effectively reduces the temperature of an LED large screen, improves the display effect and prolongs the service life.