36results about How to "Low dielectric loss value" patented technology

The invention discloses a halogen-free resin composition, a prepreg prepared from the halogen-free resin composition and a laminated board prepared from the halogen-free resin composition and used for a printed circuit. The halogen-free resin composition comprises alkylphenol epoxy resin, benzoxazine resin, an alkylphenol aldehyde curing agent and a phosphorus-contained flame retardant. The molecular structure of alkylphenol epoxy resin adopted in the halogen-free resin composition contains more branched alkyls, so that the halogen-free resin composition is relatively high in glass transition temperature, low in water absorption rate, favorable in heat resistance and excellent in dielectric performance; benzoxazine resin is mixed, so that the dielectric constant, dielectric loss value and water absorption rate of a solid can be further reduced; alkylphenol aldehyde is used as a curing agent, so that the advantages of excellent dielectric performance and low water absorption rate generated by more alkyls in the structure are sufficiently exerted. The prepreg prepared from the halogen-free resin composition and the laminated board prepared from the halogen-free resin composition and used for the printed circuit have the advantages of low dielectric constant, low dielectric loss factor, low water absorption rate, high size stability, high heat resistance, and favorable flame retardance, processability and chemical resistance.

The invention relates to an epoxy resin composition, and a prepreg and a laminated board with the epoxy resin composition. The epoxy resin composition comprises imide-modified active ester and epoxy resin. The imide-modified active ester resin composition has good process workability and solubility. With the composition, the advantages of no secondary hydroxyl generation and intrinsic good dielectric properties of active ester resin cured epoxy resin are maintained. Also, imide group with better heat resistance is introduced into the main chain, such that the heat resistance of existing active ester is improved. The prepreg and laminated board prepared with the composition has the advantages of high glass transition temperature, low dielectric constant, low dielectric loss value and low water absorption.

The invention discloses a triphase-body nanometer composite material with high dielectric constant and high elasticity and a preparation method thereof, wherein the triphase-body nanometer composite material comprises an inorganic material and an organic material, wherein the inorganic material comprises conductive stuffing carbon black (CB) powder and barium titanate BaTiO3 (BT) and the organic material comprises methylvinylsiloxane rubber (VMQ). The triphase-body nanometer composite material has the formula in a volume ratio: 0.5 to 4% of CB powder body, 40% of barium titanate powder body (BT) and 56 to 59.5% of methylvinylsiloxane rubber (VMQ). The preparation method comprises the steps of: heat-treating the BT powder and the CB powder, grinding and formulating a VMQ solution, carrying out pressure moulding by adopting a solution mixing and low-temperature hot pressing vulcanization method, and carrying out post treatment. The triphase-body (CB/BaTiO3/VMQ) nanometer composite material disclosed by the invention has the advantages of high dielectric constant, low dielectric loss and high elasticity; and a hot pressing method for reducing forming temperature, shortening preparation time and being convenient for forming is adopted; and the composite material with stable performance and fine tenacity is obtained in a shorter time, therefore time and energy are saved.

The embodiment of the invention discloses a method for manufacturing a high dielectric composite thin film. The method comprises the following steps of: uniformly mixing micron barium titanate, nano strontium titanate and polyvinylidene fluoride powder; dissolving the mixed material powder in an organic solvent; carrying out standing vacuum defoaming on organic mixed solution at the room temperature; carrying out casting knifing on the organic mixed solution on a substrate to form a flat plate film; and heating the flat plate film so that the organic solvent is evaporated to obtain a polyvinylidene fluoride-barium titanate-strontium titanate composite thin film. With the adoption of the method of the embodiment of the invention, strontium titanate particles with nano partical sizes can be filled in gaps among barium titanate particles with micron particle sizes, the barium titanate particles can be stacked more closely, and therefore, a dielectric constant of the obtained composite thin film can be improved greatly and loss can be reduced.

The invention relates to a halogen-free thermosetting resin composition and a prepreg and a printed circuit laminate employing the halogen-free thermosetting resin composition. An organic condensate of the halogen-free thermosetting resin composition comprises the ingredients in parts by weight (based on 100 parts): (A) 5-50 parts of cyanate resin; (B) 5-40 parts of polyphenylether resin; (C) 5-30 parts of phosphoric bisphenol polymer; (D) 30-60 parts of halogen-free epoxy resin. The prepreg and the printed circuit laminate made from the halogen-free thermosetting resin composition, provided by the invention, have high glass transition temperature, excellent dielectric properties, low water absorption rate, high heat resistance, high peel strength, excellent humidity resistance and good process processability, can achieve no halogen and flame retardance and reaches UL94 V-0.

The invention discloses a halogen-free polyphenyl ether resin composition. The composition comprises the following components: (a) 100 parts of polyphenyl ether resin containing carbon-carbon unsaturated bonds; (b) 5-60 parts of a phosphorus-containing compound containing carbon-carbon unsaturated bonds; and (c) 0-10 parts of an initiator. According to the invention, the phosphorus-containing compound containing carbon-carbon unsaturated bonds is used as a cross-linking agent for polyphenyl ether and a compound containing carbon-carbon unsaturated bonds, so that the polyphenyl ether and the compound containing carbon-carbon unsaturated bonds can be well and uniformly compounded together, and a lower dielectric constant and a lower dielectric loss value are obtained. Experimental data proves that the resin composition and the laminated board prepared from the resin composition can meet requirements of current 5G products.

The embodiment of the invention discloses a preparation method of a high-dielectric polymer composite film. The preparation method is characterized by comprising the following steps of: sufficiently mixing a main material A and a certain quantity of first solvent to obtain a first slurry; mixing an organic dielectric material B with high dielectric constant and low loss and a certain quantity of second solvent, and dispersing the mixture to obtain a second slurry; sufficiently mixing the first slurry and the second slurry to obtain a third slurry; standing and curing the third slurry in a vacuum container to obtain a uniformly-mixed gel-state high-dielectric organic composite; and adding the gel-state high-dielectric organic composite into an extruding machine for heating and extruding, quenching a molten film through a cooling roller after the molten film is extruded, stretching the extruded cooled film in two ways through a film stretch forming machine, and finally, carrying out heat setting at the temperature of 150 DEG C to obtain the high-dielectric polymer composite film. The film has a high dielectric constant value, a high breakdown voltage value and a low dielectric loss value.

The invention provides a halogen-free thermosetting resin composition, a prepreg comprising the same, a laminated board and a printed circuit board. The halogen-free thermosetting resin composition comprises the following substances serving as necessary components, in 100 parts of organic solid matters by weight: (A) 35-65 parts of halogen-free epoxy resin; (B) 10-35 parts of poly-phosphonate; (C) 10-30 parts of cyanate ester. The halogen-free thermosetting resin composition, the prepreg comprising the same, the laminated board and the printed circuit board have high glass transition temperature, excellent dielectric property, high peeling strength, high heat resistance, low water absorption and good process machinability, can realize halogen-free flame resistance and reach UL94 V-0.

The invention relates to a halogen-free thermosetting resin composition and a prepreg, a laminated board, a coated metal foil laminated board and a printed circuit board using it. According to 100 parts by weight of organic solid matter, the halogen-free thermosetting resin composition is prepared from, by weight, (A) 25-55 parts of phosphorus containing epoxy resin, (B), 10-40 parts of active ester curing agent, (C), and 20-50 parts of bisphenol fluorine benzoxazine resin. The laminated board prepared by the halogen-free thermosetting resin composition is featured by high glass-transition temperature, low dielectric loss factor, high heat resistance, low water absorption, and good fire resistance, processing performance, and chemical resistance.

The invention relates to an epoxy resin composition and a prepreg and laminated board using same.The epoxy resin composition is prepared from novolac epoxy resin, core-shell rubber-toughened epoxy resin or/and core-shell rubber, bromized bisphenol A epoxy resin, four-functional-group epoxy resin, active ester and a linear phenolic resin compound curing agent.Adopted novolac epoxy resin has high glass-transition temperature, low water absorption and excellent dielectric property at the same time, core-shell rubber-toughened epoxy resin can improve toughness and technical processablity, bromized bisphenol A epoxy resin provides flame retardance while raising glass-transition temperature, and the active ester and the linear phenolic resin compound curing agent are beneficial for realizing balance among heat resistance, dielectric property and water absorption and reducing cost at the same time.The prepreg and laminated board made of the epoxy resin composition are high in heat resistance, small in dielectric loss value, high in humidity resistance, low in water absorption and good in toughness.

The invention provides a resistance measurement method for a shielding layer of a large hydrogenerator stator bar. The resistance of the shielding layer of the processed and molded stator bar can be measured by a lead-out copper bar; and the dielectric loss value of the stator bar can be reduced after the lead-out copper bar is connected with a stator bar outgoing line.

The invention discloses a terahertz waveband medium material, a preparation method and a method of preparing a dielectric medium therefrom. The chemical formula of the medium material is [(Mg<1 x>Al<2/3x>)<1/3>Nb<2/3>]O<2> + y wt% ABSMV, 0<=x<=0.3, and y=1 or 2. The medium material has the advantages of low sintering temperature, low dielectric loss, and moderate dielectric constant.