68results about How to "Stable dielectric properties" patented technology

The invention discloses a dielectric composite material for a fingerprint sensor induction layer and a preparation method thereof. The dielectric composite material is prepared from an epoxy resin, a phenol aldehyde resin, a first dielectric inorganic filler, a second dielectric inorganic filler, a curing agent, an adhesion accelerator, a releasing agent and a flame retardant. The dielectric composite material has the advantages of high dielectric constant, small dielectric loss, stable dielectric properties (can not greatly change along with test frequency), non-transparency and high hardness; and the prepared fingerprint sensor induction layer satisfies the requirements for reliability and stability on the premise of achieving the thickness requirement, and can be used in various portable electronic products. The dielectric composite material is free of heavy metal lead, and thus, is green and environment-friendly. The dielectric composite material is convenient and safe; and thus, the terminal not only can be substituted for the existing digital-input cryptographic identification system, and can also be used on any electronic component in need of privacy.

The invention provides a thermosetting resin composition, comprising a diallyl compound, wherein the structural formula of the diallyl compound is as shown in formula (1), wherein R1 is -C(CH3)2, -C(CF3)2, -SO2, -CH(CH3), -CH2 or oxygen atom; R2 and R3 are the same or different aliphatic chain alkyls or aromatic alkyls; and R2 and R3 contain no allyl group. The thermosetting resin composition are excellent in heat stability and humidity resistance, low in dielectric constant and dielectric loss angle tangent, and excellent in processability. The embodiment of the invention also provides applications of the thermosetting resin composition in a resin sheet, a resin compound metal foil, a prepreg, a laminated board, a metal foil covered laminated board and a printed circuit board.

The invention relates to a high-voltage-resistant and high-energy-density capacitor and a preparation method thereof. The high-voltage-resistant and high-energy-density capacitor comprises a substrate, a bottom electrode, a dielectric layer and a top electrode, wherein Si or SiO2 / Si is taken as the substrate; the bottom electrode is a metal film, a conductive oxide film or a combination of both; the dielectric layer consists of a BaTiO3 ferroelectric film; and the top electrode is a metal film point electrode. A metal target or / and conductive oxide target is adopted, and a single target is used for depositing a metal film or a conductive oxide film, or depositing the meal film and the conductive oxide film in sequence on the substrate in a radio-frequency or direct current magnetron sputtering way; a ceramic BaTiO3 target is adopted, and a BaTiO3 layer is deposited on the bottom electrode in a radio-frequency magnetron sputtering way; and a metal target is adopted, and the top electrode is deposited in a radio-frequency magnetron sputtering way. The film capacitor prepared with the method has the advantages of small size, high voltage resistance and breakdown field strength Eb of higher than 1000kV / cm; the practical discharging energy density is not less than 10J / cm<3>; and the loss is low, and the dielectric performance is kept stable when the frequency and temperature change.

The invention discloses a manufacturing method of a modified teflon copper-clad plate. The method comprises the following steps: (1) modifying sodium-naphthalene treated teflon through a grafting monomer to obtain modified teflon; (2) modifying a filler through a coupling agent to obtain a modified filler; (3) dispersing the modified teflon obtained in the step (1) into kerosene, then adding the modified filler obtained in the step (2), mixing to obtain a slurry; (4) coating the slurry obtained in the step (3) on a copper foil, and pressing to obtain the modified teflon copper-clad plate. Thepressed copper-clad plate does not contain a glass fabric and effectively avoids the effect of glass weaving; the pressed teflon copper-clad plate has the advantages of stable dielectric property, lowcoefficient of thermal expansion, good size stability and the like.

The invention discloses a magnetic isolation sheet applied to wireless charging and near field communication (NFC). The magnetic isolation sheet comprises at least one magnetic isolation unit, whereinthe magnetic isolation unit comprises a soft magnetic strip and a double-side adhesive tape, wherein the soft magnetic strip is of a sheet structure with two exposed surfaces, the double-side adhesive tape covers one of the exposed surfaces, and the other exposed surface of the soft magnetic strip is pressed to form a mesh-shaped line. The invention also discloses a fabrication process of the magnetic isolation sheet applied to wireless charging and NFC. The fabrication process comprises the steps of constructing a magnetic isolation unit, in which the double-side adhesive tape is pasted ontoone of the exposed surfaces of the soft magnetic strip by taking the soft magnetic strip of the sheet structure with the two exposed surfaces as an element, and the other exposed surface of the softmagnetic strip is pressed to form the mesh-shaped line; and constructing the magnetic isolation sheet. The magnetic isolation sheet applied to wireless charging and NFC, fabricated by the fabricationprocess has the advantages of thin thickness, good magnetic isolation capability, high charging efficiency, NFC working frequency stability and high product stability, and the process and the materialcost are greatly reduced.

The present invention relates to artificial crystal synthetic mica and its preparation process. Its raw material composition includes (by wt%) 33%-37% of quartz, 28%-31% of magnesium oxide, 9%-12% of aluminium oxide, 18%-21% of potassium fluorosilicate and 0.3%-0.4% of potassium carbonate. Its preparation process includes the procedures of preparing raw materials, processing in container and melting, etc.

The invention discloses a method for preparing a nanocomposite dielectric film. The method comprises the following steps of: firstly obtaining a polymer dielectric film by a Langmuir-Blodgett (LB) film method; secondly preparing a high-dielectric inorganic / organic composite nanoparticle film on the polymer dielectric film by the LB film method; and finally preparing a polymer dielectric film on the composite nanoparticle film by the LB film method, thereby forming a high-dielectric composite film material with nanoparticles dispersed in a polymer. The polymer-nanoparticle composite dielectric film material prepared by the method overcomes the shortcomings of the prior art, and the preparation method is reasonable and simple, and easy to operate.

The present invention relates to a resin composition for high-frequency electrical and electronic components and a molded article thereof. An object of the present invention is to provide a thermoplastic resin composition, a sheet-like molded product, and a copper-clad laminate, which are excellent in molding processability such as extrusion processability and injection moldability, solder heat resistance, and bending It has excellent mechanical properties such as properties, durability, and drillability, and satisfies the low dielectric loss required for high-frequency band electrical communication components. The present invention relates to a molded body composed of a resin composition in which specific graphite is added to a resin composition mainly composed of (a) polyarylene sulfide resin and (b) polyphenylene ether resin. The present invention also relates to a multi-layer molded body, the inner layer of which is composed of (a) polyarylene sulfide resin and (b) polyphenylene ether resin as the main components of the resin combination The outer layer of the multilayer molded body is made of a resin composition without adding metal oxides. The present invention further relates to a copper-clad laminate produced by laminating copper foil or copper plating on one or both surfaces of the above-mentioned molded body or multilayer molded body.

Provided is a dielectric composite material for a fingerprint sensor induction layer and a preparation method therefor, wherein the dielectric composite material is made from the following components: an epoxy resin, a phenolic resin, a first type of dielectric inorganic filler, a second type of dielectric inorganic filler, a curing agent, an adhesion promoter, a mould releasing agent and a flame retardant. The dielectric composite material has a high dielectric constant, a small dielectric loss, very stable dielectric properties which change very little with the test frequency, non-transparency and high hardness, such that the fingerprint sensor induction layer prepared therefrom satisfies the requirements of reliability and stability while reaching the thickness requirement, and can be used in various portable electronic products. The dielectric composite material for the fingerprint sensor induction layer is free of heavy metal lead, and is green and environmentally friendly. The dielectric composite material has convenience and high safety, and therefore the terminal application thereof can not only replace the existing digital-input password identification system, but can also be used on any electronic component in need of security.

The invention provides a composite material and a sheet for a microwave circuit base plate, and the microwave circuit base plate and a preparation method thereof. The preparation method of the composite material comprises the following steps: 1) mixing a polytetrafluoroethylene dispersion emulsion, an inorganic filler and a coupling agent to obtain a glue solution; 2) adding a settling agent intothe glue solution, demulsifying, centrifugally separating to obtain a slurry mixture, and drying the slurry mixture to obtain a solid; 3) crushing the solid to obtain powder, mixing the powder and a lubricant, and aging to obtain an aged material; 4) stirring the aged material to fibrillate the aged material to obtain a fibrillated material; 5) heating the fibrillated material to remove the lubricant to obtain powder; 6) conducting isostatic pressing on the powder in a mold to obtain a hollow round billet, and conducting heat treatment to remove internal stress; 7) sintering the hollow round billet; and 8) conducting rotary cutting on the round billet to form continuous sheets. The sheet prepared from the composite material can achieve large-area industrial production and has stable dielectric properties.

The invention discloses a high-temperature-resistant weatherproof fireproof chlorinated polyvinyl chloride (CPVC) corrugated board with low heat conductivity, and a preparation method of the chlorinated polyvinyl chloride (CPVC) corrugated board. The corrugated board is prepared from the following raw materials by weight: 10-60 parts of CPVC resin, 30-70 parts of PVC (polyvinyl chloride) resin, 1-8 parts of composite lead salt stabilizer, 1-4 parts of processing aids, 8-12 parts of anti-impact aids, 25-75 parts of filler, 1.5-4.5 parts of lubricant, and a reasonable amount of colorant. The corrugated board has the advantages of high mechanical strength, excellent weatherability, high aging resistance and chemical stability and the like, and the formed raised corrugated board has higher thickness uniformity and uniform stress distribution, thereby being not easy to break due to stress concentration.

The invention discloses a preparation method of a high-strength high-temperature-resistant polyarylene ether nitrile film. The preparation method comprises the specific steps of preparing phthalonitrile-terminated polyarylene ether nitrile; preparing a biphenyl type bisphthalonitrile prepolymer; blending and dissolving the obtained phthalonitrile-terminated polyarylene ether nitrile powder and biphenyl bisphthalonitrile prepolymer powder in N-methyl pyrrolidone, and heating and stirring to obtain a transparent solution; and carrying out film forming by a tape casting method, heating, carrying out heat treatment, and naturally cooling to obtain the high-strength high-temperature-resistant polyarylene ether nitrile film. The film obtained by the invention not only has high glass transition temperature, high tensile strength and high modulus, but also has stable dielectric properties.

The invention discloses a preparation process of a wireless charging application shielding sheet. The wireless charging application shielding sheet comprises at least one longitudinally superposed shielding layer, wherein each shielding layer is formed by transversely splicing at least one soft magnetic shielding unit. The preparation process comprises the following steps: selecting soft magneticmaterials, and performing winding and heat treatment on the soft magnetic materials sequentially to obtain a substrate with two exposed surfaces; coating one exposed surface of the substrate with a double-sided adhesive tape, and cutting and vibrating the other exposed surface of the substrate by combining energy wire cutting and acoustic wave vibration to decompose the substrate into a pluralityof thin sheets in uniform shapes and certain size and obtain a soft magnetic shielding unit. The invention further discloses the wireless charging application shielding sheet. The wireless charging application shielding sheet comprises at least one shielding layer, a colloidal protective film and a PET film. The preparation process is simple and feasible, the shielding sheet is thin, good in shielding capability, high in charging efficiency and stable in work, and the process cost and the material cost are greatly saved.

The invention relates to a composite application shield sheet of a coil module and a preparation process thereof. The preparation process comprises, at least, the following process steps of heat treatment, composite lamination and soft magnetic material surface graphical processing. magnetic sheets formed by a resin bonding agent and a magnetic powder mixture are attached to the back of a first magnetic conductive layer formed by soft magnetic material strip laminations undergoing graphical processing or upper-single-layer graphical processing to form a second magnetic conductive layer; then cooling fins are attached to finally form the shield sheet, and finally the coil module is formed through shaped attachment. The process is simple and feasible, the integrated automation degree is high, the made shield sheet is small in thickness, good in shield capability, high in charging efficiency, small in temperature rise and more suitable for NFC composite functional module coils, the magnetic parameters of the materials are controllable, the surface processing shape of the shield sheet is uniform, the product stability is improved, and the processes and material costs are greatly saved.

Disclosed is a dielectric gelling composition, exhibiting a thermo-reversible liquid-gel transition at a transition temperature, Tt, wherein the gel comprises an oil and a combined gelator system having molecules of a polymer compound together with fine dielectric particles with a particle size in the nanomneter range, preferably a particle size within the range from 0.001 to 1000 nm, the use of this dielectric gelling composition in an electric device comprising one or more conductors, a casing or enclosure and an insulation system comprising the dielectric gelling composition. An electric DC-cable having a conductor and an electrical insulation comprising a solid part with a porous, fibrous and / or laminated structure impregnated with the dielectric gelling composition and a method for production of such DC-cable wherein the combined gelator is prepared prior to impregnation are also disclosed.

The invention discloses a method for effectively improving Curie temperature of a barium titanate-based dielectric material. The method comprises the following steps: batching Na2CO3, Bi2O3 and TiO2 according to a molar ratio of 1:(0.95-0.65):2, performing ball-milling, drying, calcining at the temperature of 950 DEG C, preparing sodium bismuth titanate powder, adding the sodium bismuth titanate powder into barium titanate according to 15-20 weight percent, ball-milling, screening and pelleting, pressing into a green body, sintering at the temperature of 1200-1240 DEG C, and preparing the barium titanate-based dielectric material. The Curie temperature of the barium titanate-based dielectric material can be effectively improved (the highest Curie temperature can be 200 DEG C), so that a multiplayer ceramic chip capacitor can keep stable dielectric property in a high-temperature environment of more than 150 DEG C).

The invention discloses a low-dielectric polyperfluorinated ethylene propylene copper-clad plate and a preparation method thereof. The preparation method comprises the following steps: performing pretreatment on chopped glass fibers, performing modification with a silane coupling agent, adding a dispersing agent to perform fluffing by a fluffer, and enabling the glass fibers to be uniformly dispersed; drying the dispersed glass fibers to remove water, adding polyperfluorinated ethylene propylene emulsion, uniformly mixing the polyperfluorinated ethylene propylene emulsion and the glass fibers,and performing dehydration and concentration; coating a high temperature resistant film with a concentrated solution uniformly by using an automatic coater; performing vacuum drying, and taking out the materials after cooling so as to prepare a polyperfluorinated ethylene propylene prepreg; and attaching the prepreg onto a copper foil, and performing pressing by a hot press so as to obtain the copper-clad plate. The copper-clad plate is prepared by selecting a polyperfluorinated ethylene propylene resin, and has a dielectric constant value up to 2-2.5, a dielectric loss value up to 0.0008-0.0015 and the water absorption rate of 0.02-0.05%. The copper-clad plate disclosed by the invention is excellent in dielectric property, low in water absorption rate, good in cohesive property and highin machinability.

The invention relates to a millimeter wave printed dipole antenna array radiating element and an array antenna. The millimeter wave printed dipole antenna array radiating element include a dielectricsubstrate, a feed strip line, and a dipole antenna. First, two dipole antennas are printed on the two surfaces of the dielectric substrate respectively so as to enhance the radiating and receiving capabilities of the dipole antennas. Secondly, because the projection of the feed strip line in the horizontal direction and the projection of a slot in the horizontal direction intersect each other, theslot is divided into two sections, the upper section of which is a series feed slot, and the lower section of which is a balance / unbalance conversion structure. The series feed slot moves the radiating arms of the dipole antennas upward to facilitate feeding. The balance / unbalance conversion structure improves the working frequency band of the dipole antennas such that the dipole antennas can operate in a wide frequency band. Thus, the millimeter wave printed dipole antenna array radiating element that is convenient for feeding and can operate in a wide frequency band is achieved, and is simple in structure and easy to machine.

The present invention relates to a novel ZnTiO3-based dielectric material, having the composition represented by the formula (Zn1-aMga)(Ti1-b-cMnbDc)dO3, wherein D is an element having a valence of 5 or above, 0<=a<=0.5, c<=b<=0.1, 0<c<=0.1, 1<=d<=1.5, which has properties of ultra low sintering temperature, high reliability, and high dielectric strength, and is capable of being applied to produce low capacitance multilayer ceramic capacitor with high quality factor, low ESR, and high insulation resistance. The present invention also relates to a method of preparing such a novel ZnTiO3-based dielectric material.

The invention discloses a low-dielectric bismaleimide resin system. The low-dielectric high-performance bismaleimide resin system is prepared from bismaleimide, an allyl compound, mesoporous silica and polyphenylene ether by preparing polyphenylene ether-coated mesoporous silica and applying the polyphenylene ether-coated mesoporous silica to a bismaleimide resin system. A method disclosed in theinvention has the characteristics of simple process, extensive applicability and the like. The produced low-dielectric bismaleimide resin system has good application potential in fields of aviation, spaceflight and electronics.

The invention relates to a negative resistance temperature coefficient zinc oxide linear resistance ceramic material and a preparation method, which belong to the technical field of functional ceramic material manufacture. The negative resistance temperature coefficient zinc oxide linear resistance ceramic material is characterized by comprising, by mole percentage, zinc oxide 90%-95%, magnesium oxide 1.0%-3.0%, aluminum oxide 3.0%-5.0% and metasilicic acid 1.0%-3.0%. By adjusting reasonable proportion of functional additives and adopting the negative resistance temperature coefficient zinc oxide linear resistance ceramic material prepared by a high energy grinding preparation technology, products have excellent comprehensive performance, the optimal nonlinearity coefficient can reach 1.0, the dielectric property can be stable in a high frequency region, the dielectric constant is in a range of 0.6*104-1*104, the resistivity is 40-50 ohm / centimeter, the temperature resistance coefficient is in a range from -3.7*10-3 to -3.6*10-3 ohm / DEG C.

The invention discloses polyimide fiber mica paper which is formed by causing modified mica and modified polyimide fiber to undergo on-line processing in a paper sheet machine. The invention further discloses a method for preparing the mica paper. The method for preparing the mica paper comprises the steps of preparing modified mica; causing the modified mica to undergo defibering to make mica slurry; making concentrated solution of polyimide into polyimide fiber, and causing the polyimide fiber to undergo fiber bundle removal and then be modified through phosphoric acid; adding PEO into the polyimide fiber to serve as a dispersing agent, adding the polyimide fiber into the mica slurry, and obtaining the polyimide fiber mica paper through on-line forming hot-pressing drying. The paper has more stable dielectric properties and temperature resistance, the quality of an insulating material is improved, the service life of the material is prolonged, the stability of the material is improved, and the electrical industry development is promoted effectively. Besides, the polyimide fiber mica paper is simple in process steps, the controllability of process parameters is high, the raw material source is extensive, raw materials are low in price, the production conditions are mild, and the application prospect is wide.

The invention discloses a method for preparing a nanocomposite dielectric film. First, a polymer dielectric film is obtained by a Langmuir-Blodgett (LB) film method, and then a high dielectric inorganic / The organic composite nanoparticle film is finally prepared on the composite nanoparticle film by the LB film method to prepare a polymer dielectric film, thereby forming a high dielectric composite film material in which nanoparticles are dispersed in the polymer. The polymer-nano particle composite dielectric film material prepared by the method overcomes the defects in the prior art, and the preparation method is reasonable and simple, and is easy to operate.

The invention discloses a multifunctional modified resin blended prepreg hydrocarbon composition and an application thereof, and a method for preparing a high-frequency high-speed copper-clad plate byusing the prepreg hydrocarbon composition. The prepreg hydrocarbon composition comprises the following components: 20-60 parts of multifunctional modified resin; 25 to 65 parts of an inorganic filler; 10 to 50 parts of a flame retardant; 0.1 to 10 parts of an antioxidant; and 2-10 parts of a cross-linking agent. The multifunctional modified resin is one or more of a hydroxyl modified polybutadiene polymer, a hydroxyl modified polybutadiene-styrene copolymer, sulfydryl modified polybutadiene, polyether modified polybutadiene, an isoprene-styrene copolymer, a styrene-butadiene-styrene copolymerand a butadiene-acrylonitrile copolymer. The special multifunctional modified resin blended prepreg hydrocarbon composition for the high-frequency copper-clad plate provided by the invention has thecharacteristics of low dielectric constant, low dielectric loss, excellent heat resistance, good thermal mechanical properties, extremely low water absorption and stable performance.

The invention discloses a poly-n-butyl methacrylate (PBMA) / polyvinylidene fluoride vinyl compound dielectric film. The film is formed by performing mixing and tape casting on florin-containing polymer and organic PBMA. The compound dielectric film is composed of, by mass percent, the components of 10%-30% of the organic PBMA and 70%-90% of the florin-containing polymer. The compound dielectric film is novel dielectric materials which are high in dielectric constant and low in dielectric loss. The compound dielectric film with the needed dielectric constant can be prepared by controlling the filler appending proportion. The compound dielectric film is simple in preparation technology, low in compound temperature and friendly to environment, and has a wide application prospect.

The invention relates to the field of energy storage thin-film materials and discloses a lead-free epitaxial thin film with wide working temperature and a preparation method thereof. The lead-free epitaxial thin film comprises a Nb:SrTiO3 substrate and a thin film body, wherein the thin film body is arranged on the upper surface of the Nb:SrTiO3 substrate; the thin film body is Ba0.3Sr0.7TiO3 / 0.85BaTiO3-0.15Bi(Mg0.5Zr0.5)O3 composite multilayer thin film; and the structure of the lead-free epitaxial thin film is Nb:SrTiO3 / Ba0.3Sr0.7TiO3 / 0.85BaTiO3-0.15Bi(Mg0.5Zr0.5)O3. The lead-free epitaxialthin film with wide working temperature does not contain lead and has excellent energy storing property, and more importantly, the lead-free epitaxial thin film has high thermal stability within the wide temperature area of 25-250 DEG C, and the working temperature of the lead-free epitaxial thin film is far higher than that of other lead-free thin films.

The invention relates to an olefin-benzoxazine copolymer oligomer, cross-linked resin and a preparation method of the olefin-benzoxazine copolymer oligomer and the cross-linked resin. A free radical initiator is selected, a benzoxazine monomer containing double bonds and a diene monomer are adopted for free radical binary copolymerization, or a third monomer styrene is added for free radical ternary copolymerization, olefin-benzoxazine copolymerization oligomers are synthesized, and the copolymerization oligomers are soluble by controlling the reaction degree. Then, further heating is carriedout to enable the benzoxazine ring to be subjected to a ring-opening reaction; consequently, cured resin is produced, according to the invention, the low dielectric property of hydrocarbon resin and the excellent performance of polybenzoxazine are combined together at the molecular level; the problem of compatibility between resins is solved, and the composition proportion of polydiene and polyoxazine in a molecular chain can be regulated and controlled in a large range, so that a novel high polymer material with low dielectric constant, low dielectric loss, high heat resistance and high adhesive property is obtained.

The invention discloses a manufacturing process of a two-dimensional material filled copper-clad plate, which comprises the following steps: S1, modifying a two-dimensional material by using a modifier to obtain a modified two-dimensional filler; S2, mixing a base material and a dispersing agent, obtaining dispersion emulsion, wherein the base material is PTFE or polyphenyl ether resin; S3, addingthe modified two-dimensional filler into the dispersion emulsion, fully and uniformly mixing, transferring into an impregnation tank, impregnating the dispersion liquid with glass fiber cloth, and carrying out heat treatment to obtain prepregs; and S4, pressing the prepreg and copper to obtain the two-dimensional material filled copper-clad plate. The modified two-dimensional material is used asa dispersion phase to be added into a matrix material, so that the prepared copper-clad plate has a relatively low dielectric constant, relatively low dielectric loss and relatively high thermal conductivity, is stable in dielectric property, and can meet the performance requirements of a high-frequency circuit in the 5G era.

The invention relates to the field of preparation of dielectric film materials, in particular to a nanometer indium tin oxide doped high-dielectric polypropylene-based composite dielectric film for a film capacitor and a preparation method thereof. The composite film uses a polypropylene film with the thickness smaller than or equal to 5 microns as a basic film, a spherical ferroferric oxide magnetic powder and nanometer indium tin oxide doped nano crystalline cellulose / polyvinylidene chloride composite coating with the thickness smaller than or equal to 5 microns is arranged on the surface of the basic film, has good compatibility with the polypropylene film, is firm in absorption, excellent in mechanical property, high in strength and good in toughness and has higher dielectric constants and lower dielectric loss, the dielectric performance is stable, the advantages of organic / inorganic dielectric materials are fully integrated, and the nanometer indium tin oxide doped high-dielectric polypropylene-based composite dielectric film is suitable for large-scale production and can be used for production of the small-sized large-capacity light-weight film capacitor.

The invention discloses a preparation method of a wireless charging shielding sheet and the shielding sheet, and belongs to the technical field of electromagnetic shielding, and the method comprises the steps: S1, carrying out the heat treatment of a soft magnetic material strip, and forming a substrate; S2, forming at least one shielding layer unit; S3, superposing at least one shielding layer unit to form a shielding sheet structure; S4, pressurizing and crushing the shielding sheet structure through a roller with a preset pattern arranged on the surface; and S5, enabling the upper and lowersurfaces of the shielding sheet structure to be attached to a heat dissipation film, and forming a wireless charging shielding sheet, wherein the shielding sheet comprises a shielding sheet structureand a heat dissipation film, the shielding sheet structure comprises at least one shielding layer unit, and each shielding layer unit comprises a base material and colloid. The technical scheme has the beneficial effects that the shielding sheet obtained after graphical processing is uniform in shape and grain size, good in gap size consistency, good in colloid filling property, large in impedance on the surface of the shielding sheet, small in eddy-current loss, stable in dielectric property and easy to produce in batches.