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

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.

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 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.

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 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 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.