100results about How to "Low dielectric dissipation factor" patented technology

The invention relates to a thermosetting resin composition and a prepreg and a laminate for printed circuits thereby. The thermosetting resin composition comprises at least an epoxy resin with a component being the structural formula (I) and a curing agent. The molecular structure of the epoxy resin composition of the invention contains the low-polarity styrene structure, therefore, the dielectricproperty of the resin is optimized. The dielectric constant and the dielectric loss angle tangent are reduced compared with those of the common epoxy resins. The prepreg obtained by coating the resincomposition on the substrates and the laminate manufactured by laminating the prepreg simultaneously have the characteristics of low dielectric constant, low dielectric dissipation factors, good heatresistance, good dip soldering resistance, good moisture resistance, good humidity resistance and good cohesiveness with copper foils. The resin composition of the invention can be also used for manufacturing the resin sheets, resin composition copper foils, the laminate and the printed circuit boards. R is (a), and n and m are natural numbers.

The preparation process of novel high performance copper-clad PTFE plate includes the following steps: preparing inner layer of glass fiber fabric; preparing outer layer of glass fiber fabric; and cladding copper foil on two sides of the outer layer of glass fiber fabric. The copper-clad PTFE plate of the present invention has excellent electric performance, heat performance and mechanical performance, high bending strength, high size stability and high comprehensive performance.

The present invention relates to an adhesive resin composition for fabrication of circuit boards and its use. The adhesive resin composition of the present invention includes a cyanate ester resin, a fluorine-based resin powder dispersed in the cyanate ester resin, and a rubber component and has low dielectric constant and low dielectric loss factor, which enables the fabrication of circuit boards with further enhanced electrical characteristics.

The invention particularly relates to a halogen-free flame retardant prepolymer, and an application thereof in the manufacture of the copper clad laminate (CCL). The manufacture of the CCL comprises the following steps: taking and reacting the bismaleimides, allyl compound and phosphorus-containing compound for 10 to 120 minutes at the temperature of 80 to 160 DEG C to obtain the halogen-free flame retardant prepolymer; preparing the prepolymer into solution, stirring uniformly the solution to obtain a glue solution, coating the glue solution uniformly on an E-glass fiber cloth with smooth surface, and then baking the E-glass fiber cloth to prepare a B-rank prepreg; and cutting the B-rank prepreg into proper size according to the size of a pressing machine, overlapping a certain amount of prepregs, and pressing the prepregs with a copper foil with the same size on the top and a copper foil with the same size at the bottom in a hot pressing machine to obtain the CCL. The CCL has good flame retardant effect, no release of harmful gases during the burning, and the product after the solidification of the CCL has the advantages of good toughness, higher thermal decomposition temperature and lower dielectric loss.

The invention relates to a thermosetting resin composition and a prepreg and a laminate for printed circuits thereby. The thermosetting resin composition comprises at least an epoxy resin of the structural formula (I) and a cyanate resin. The thermosetting resin composition of the invention has high heat resistance, low dielectric constant and low dielectric dissipation factors, thus being used for manufacturing the resin sheets, resin composition copper foils, the prepregs, the laminate and the printed circuit boards. R is (a), and n and m are natural numbers.

An improved patch radiator is characterised by the following additional features: the radiator surface (11) is designed as an annular and/or frame-shaped radiator surface (11), extending around a recess area (13), - the radiator surface (11) is extended so as to transition into the lateral surfaces or lateral walls (3c), and on the lateral surfaces or lateral walls (3c), a lateral surface radiator structure (18) electrically connected to the radiator surface (11) is formed, comprising, in the peripheral direction of the lateral surfaces or lateral walls (3c), lateral radiator surface sections (19), between which electrically non-conductive recess areas (20) are provided.

The invention discloses a preparation method of a polyimide film with a low dielectric constant and a low dielectric loss factor. Dianhydride and diamine are adopted for preparing a polyamide acid solution, and the polyamide acid solution and additives such as nanometer fluorine-containing macromolecule powder, nanometer aluminum oxide powder and nanometer silicon dioxide powder are prepared into the polyimide film. The preparation method is characterized in that the additives account for 10-50% of the weight of polyamide acid. The obtained polyimide film with the low dielectric constant and the lower dielectric loss factor can achieve the effects that the dielectric constant is smaller than or equal to 2.6, the dielectric loss factor is smaller than or equal to 0.003 on the basis of keeping good mechanical properties, the technology is simple, and raw materials are easy to purchase and low in price.

The invention discloses heat-resistant epoxy anhydride resin suitable for vacuum pressure impregnation (VPI), which is characterized by comprising bisphenol A-type epoxy resin and liquid anhydride which are at the weight ratio of 1:0.8-1.2. The heat-resistant epoxy anhydride resin comprises no volatile cinnamic activated diluents, the cured heat-resistant epoxy anhydride resin has good resistance, high mechanical strength and low dielectric loss factor. The heat-resistant epoxy anhydride resin is suitable for the VPI insulation of the high-voltage motor, the wind power motor, the nuclear power motor and the coil and the impregnation of the electric generator and can meet the technical requirement for the insulation of the single coil bar for the large-scale hydroelectric generating unit and the steam-turbine generatoing unit.

The invention discloses a halogen-free low water-absorbent thermosetting flame retardant resin composition. The composition consists of the following components in parts by weight: 25-75 parts of polycyclic benzoxazine resin, 10-50 parts of multi-functional epoxy resin, 15-25 parts of phosphorus containing phenolic resin and 0.2-20 parts of hardening agent. The halogen-free low water-absorbent thermosetting flame retardant resin composition disclosed by the invention can be prepared into a bonding sheet and a copper-clad plate; the copper-clad plate is high in heat resistance, low in expansion rate, low in dielectric dissipation factor, low in water-absorbing quality and good in processing performance, and flame retardant property can satisfy UL94-V0.

The invention provides a polysiloxane-allyl compound modified polyphenylene ether resin composition, and a prepreg, a laminated board and a printed circuit board thereof. The polysiloxane-allyl compound modified polyphenylene ether resin composition comprises polyphenylene ether resin and a polysiloxane-allyl compound having a structure represented by formula I, and the composition concretely comprises 100 parts by weight of the polyphenylene ether resin and 15-80 parts by weight of the polysiloxane-allyl compound. After the polysiloxane-allyl compound is added to the polyphenylene ether resincomposition, the obtained composition has a low dielectric constant, a low dielectric loss factor, excellent heat resistance and excellent moisture absorption performance, overcomes the application disadvantage of poor adhesion between the composition and metal foil, improves the interlayer adhesion of a copper-clad plate, can achieve the UL94V-0 combustion grade without an additional flame retardant, and truly achieves halogen-free, phosphorus-free and flame-retardant effects.

The invention provides a phosphorus-containing active ester and a halogen-free resin composition thereof, and a prepreg and a laminated board using the halogen-free resin composition. The halogen-freeresin composition comprises (A) thermosetting resin, and (B) phosphorus-containing active ester resin. The prepreg and the laminated board prepared by using the halogen-free resin composition have low dielectric loss factors and can achieve halogen-free flame retardancy.

The invention discloses a low-dielectric-constant halogen-free resin composition and a low-flowability prepreg with the same. The low-dielectric-constant halogen-free resin composition comprises, by weight, 10-80 parts of epoxy resin, 5-30 parts of phenoxy resin, 10-50 parts of flame retardants, 5-50 parts of curing agents, 0-5 parts of curing accelerators, 10-80 parts of fillers, 5-30 parts of toughening agents and 0-80 parts of additives. The low-dielectric-constant halogen-free resin composition and the low-flowability prepreg have the advantages that the low-dielectric-constant halogen-free resin composition is good in wettability and sufficiently low in dielectric constant and dielectric loss tangent, and the low-flowability prepreg prepared from the low-dielectric-constant halogen-free resin composition is good in heat resistance after being cured, is low in dielectric constant and dielectric loss factor, excellent in flame retardance and good in water resistance, water absorption and cohesiveness.

The invention provides a special-shaped glass fiber and a preparation method thereof. The special-shaped glass fiber comprises the following components in percentage by mole: 52-58% of SiO2, 16-24% of B2O3, 13-19% of Al2O3, 1-5% of CaO, 4.2-8% of MgO, 0.4-2% of F2, 0-0.5% of Li2O, 0-0.4% of Fe2O3, 0-0.2% of K2O and 0-0.2% of Na2O. Compared with the prior art, the special-shaped glass fiber with a relatively-low dielectric constant and dielectric loss factor is prepared by controlling components in a formula and the contents of all the components, and meanwhile, the special-shaped glass fiber has relatively-high mechanical property, filling rate and special-shaped rate. Experiment results prove that the special-shaped glass fiber provided by the invention has the dielectric constant of smaller than 4.7 and the dielectric loss factor of smaller than 10<-3>.

The present invention is the making process of wave-permeating fiber reinforced silica-base composite material. With oxide fiber fabric as prefabricated matter, organosilicon alkoxide as precursor and high-purity argon and oxygen as carrier gas and carbon eliminating gas, part with complicated shape, thin wall and relatively precise sizes may be produced in chemical vapor permeating furnace as making equipment, and its dielectric performance can meet the requirement as antenna hood and other astronautic wave-permeating material.

Provided are: an insulating film having excellent adhesive strength to metal foil that forms FPC wiring and to FPC substrate material such as polyimide film and exhibiting electrical characteristics in the high frequency range, specifically, low dielectric constant (epsilon) and low dielectric tangent (tan delta) in the 1-10 GHz frequency range; and a resin composition used in manufacturing said insulating film. This resin composition contains (A) a thermosetting resin having styrene groups on the ends and having a phenylene ether backbone, (B) a hydrogenated styrene thermoplastic elastomer, and (C) a polytetrafluoroethylene filler, and contains 40 mass% to 80 mass% of the component (C) with respect to the total mass of the components (A)-(C).

The invention relates to a thermoplastic polyimide resin composite film with low dielectric property, and belongs to the technical field of composite film materials, the polyimide resin composite film is prepared by blending and modifying polyimide resin and LCP resin, according to the parts by weight, the polyimide resin is prepared from the following components in parts by weight: 20 to 100 parts of p-phenylene-biphenyl trimellitate dianhydride monomer, 0 to 80 parts of other copolymerized dianhydride monomer, 20 to 80 parts of diamine monomer containing fluorine group, and 20 to 80 parts of diamine monomer containing large side group. The polyimide resin has the characteristics of good solubility and good melt processability, the processing cost of polyimide is reduced, the molecular structure contains ester groups, the compatibility can be improved by blending modification with the LCP resin, the anisotropy problem caused by crystal orientation of the LCP resin is improved, the composite film is prepared, the dielectric property is further improved, and the water absorption rate is further reduced.

The invention relates to an epoxy resin containing a TCPD structure, an epoxy resin composition, a prepreg, a laminated board and a printing circuit board. The laminated board manufactured by the epoxy resin containing the TCPD structure or the epoxy resin composition has the advantages of high glass-transition temperature, high thermal decomposition temperature, low thermal expansion coefficients, low dielectric constant, low dielectric loss factors, and low water absorption rate.

The invention relates to the chemical field, and in particular relates to crosslinked polystyrene, a high-power pulse vacuum insulator and a preparation method. The crosslinked polystyrene comprises the following raw materials by mass percent: 85-98% of styrene, 1-10% of divinyl benzene, and 0.5-5% of azobisisobutyronitrile; the preparation method of the crosslinked polystyrene comprises the steps of weighing the raw materials, and mixing the raw materials; injecting the mixed raw materials into a mould; placing the mould into brine so as to conduct polymerization reaction; and drying the polymerized product. The diameter of the high-power pulse vacuum insulator is greater than 1m; the thickness of the high-power pulse vacuum insulator is greater than 0.1m; and the preparation method of the high-power pulse vacuum insulator comprises the crosslinked polystyrene preparation method, the product dried is processed into a finished product according to the size of the insulator. The crosslinked polystyrene, the high-power pulse vacuum insulator and the preparation method are applicable to insulation of the high-power pulse vacuum environment.

The invention discloses titanium-niobium-magnesium-indium acid lead pyroelectric ceramic and a preparation method thereof. The method comprises the following specific steps of: (1) dissolving lead nitrate, magnesium nitrate and indium nitrate into deionized water at the normal temperature according to a proportion in a chemical formula, adding citric acid in the molar ratio of 1:2 between citric acid and metal ions to obtain a mixed solution, dissolving niobium oxalate into deionized water, adding citric acid in the molar ratio of 1:2 between citric acid and metal ions to obtain a niobium oxalate solution, mixing a mixed solution and the niobium oxalate solution, adding into ammonia water to obtain a clarifying solution, dissolving butyl titanate into ethylene glycol to obtain a butyl titanate solution, mixing the clarifying solution with the butyl titanate solution, adjusting the pH value to obtain a precursor liquid, and drying the precursor liquid to obtain gel; (2) putting the gel into a muffle furnace for calcining to synthesize titanium-niobium-magnesium-indium acid lead powder; and (3) pressing the titanium-niobium-magnesium-indium acid lead powder into a blank, and sintering under the protection of a lead atmosphere to obtain titanium-niobium-magnesium-indium acid lead pyroelectric ceramic. The chemical formula of the ceramic is xPb(In1/2Nb1/2)O3-yPb(Mg1/3Nb2/3)O3-(1-x-y)PbTiO3, wherein x is more than or equal to 0.2 and less than or equal to 0.25, and y is more than or equal to 0.15 and less than or equal to 0.5. The ceramic has the advantages of low raw material cost, simple process and high repeatability.