45results about How to "High surface insulation resistance" patented technology

The invention discloses a method for preparing a polytetrafluoroethylene copper-clad plate, which comprises the following steps of: pretreating glass fiber cloth, preparing impregnation liquid, preparing dielectric cloth by impregnating the glass fiber cloth, and cladding copper and aluminum on the dielectric cloth, wherein the step of cladding copper and aluminum on the dielectric cloth comprises the following sub-steps of: a, cutting the dielectric cloth, copper foils and aluminum foils according to required sizes; and b, staking on a template in a sequence of an aluminum foil, a copper foil, the dielectric cloth, a copper foil and an aluminum foil, putting into a hot press, raising the temperature in a mode of wave bands, applying pressure of 6-9MPa when the temperature is between 360 and 380DEG C, cooling, and quenching when the temperature is reduced to be 200DEG C to obtain the modified polytetrafluoroethylene copper-clad plate. The dielectric cloth copper-clad plate has the dielectric loss factor reduced from 1*10<-3> to 7*10<-4>, the surface insulation resistance improved from 1*10<10> to the average 10<15>, the bending strength improved from 80MPa to average 140MPa, and the peel strength from 1.5kN/m to average 3kN/m.

The invention discloses a preparation method of dielectric cloth for preparing copper-clad plate. The method comprises the following steps of: a, performing heat treatment and drying on a glass fiber fabric; b, preparing two kinds of impregnation liquid, namely impregnation liquid I and impregnation liquid II; c, impregnating the glass fiber fabric treated in the step a in the impregnation liquid I, and drying in a drying tunnel with the temperature of between 60 and 250 DEG C; d, impregnating the glass fiber fabric treated in the step c in the impregnation liquid II and drying in the drying tunnel with the temperature of between 60 and 250 DEG C; and e, solidifying the glass fiber fabric obtained in the step d in a three-section temperature rise drying channel with the temperature of between 350 and 400 DEG C to obtain the dielectric cloth. The dielectric loss factor of the copper-clad plate prepared from the dielectric cloth is reduced from 1*10<-3> to 7*10<-4>, the surface insulation resistance is improved from 1*10<10> to mean 10<15>, the bending strength is improved from 80MPa to mean 140MPa, and the peeling strength is improved from 1.5kN/m to mean 3.5kN/m.

The invention discloses novel environmental-protection flux which comprises solvent, surfactants and an addition agent. Main ingredients of the flux comprise deionized water, polypropylene glycol 1200, hydroxybenzotriazole, secondary alcohol ethoxylate, tripropylene glycol n-butyl ether, tetraethylene glycol dimethyl ether, succinic acid and an aliphatic dicarboxylic acid mixture. The solvent of the flux is formed by mixing the deionized water of different types, alcohols and ethers. The mixed solvent has a suitable boiling point, more polar groups and moderate viscosity, and endows the flux with high activity. Few residues are generated. The effect of protecting the welding surface is achieved. Different types of the surfactants with different components are used in cooperation, and the surfactants have a good synergistic effect and can improve wettability of welding flux and prevent oxidation. The surface of the flux is clean, and the flux is free from halogen, low in carbon, environmentally friendly and capable of meeting the use requirement of welding.

The invention discloses a steel no-clean welding flux. The steel no-clean welding flux is characterized by comprising the following components in weight percent: 10-35% of organic silicon modified acrylic resin, 15-80% of mixed alcohol solvent, 5-30% of active mixed component and 1-20% of benzenediol. The invention further discloses a preparation method for the steel no-clean welding flux. The steel no-clean welding flux is an environment-friendly novel welding flux which is no-clean, good in weld assistant property, large in expansion rate, non-corrosive and residue-free.

A ferrite substrate for thin-film inductors is provided by means of blending raw materials to meet a composition of di-iron trioxide (Fe₂O₃): 40 to 55 molt %, nickel oxide (NiO): 5 to 35 molt, zinc oxide (ZnO): 10 to 40 molt %, and bismuth trioxide (Bi₂O₃): 150 to 750 ppm, or of Fe₂O₃: 40 to 55 molt %, NiO: 5 to 35 mol %, ZnO: 10 to 40 mol %, cupric oxide (CuO): 5 to 10 molt, and manganese dioxide (MnO₂): 0.5 to 2 molt %, and then molding and sintering the blended material, and applying hot isostatic pressing to the sintered article. A thin-film common mode filter and a thin-film common mode filter array using the ferrite substrate and the manufacturing method of the substrate are also provided.

The invention discloses a preparation method of a modified polytetrafluoroethylene copper clad plate, which comprises the following steps: pretreating glass fiber cloth, impregnating the glass fiber cloth, cladding copper and aluminum on the medium cloth, wherein the impregnation liquid for impregnating the glass fiber cloth is a perfluoro-alkoxy concentrated dispersion liquid modified polytetrafluoroethylene dispersion liquid. The copper clad plate using the medium cloth impregnated in the impregnation liquid has lower dielectric loss factor, higher surface insulation resistance, higher bending strength and higher peel strength.

The invention relates to the technical field of welding material and discloses a wash-free soldering flux. The flux contains the following components in terms of mass percentage: 7.0 to 8.5% of film former, 3.5 to 4.0% of active agent, 0.3 to 0.4% of surfactant, 0.20 to 0.25% of corrosion inhibitor, 0.45 to 0.50% of additive and the remaining is solvent. The above components are uniformly mixed, heated to 70 to 80 DEG C, and undergo reflux stirring reaction for 2 to 2.5 hours, cooled to 20 to 25 DEG C, and filtered to obtain the product. The wash-free soldering flux does not contain a halide active agent, has strong ability to remove metal oxides, has low spatter value and is basically non-corrosive to the device, and has good soldering quality. It has a very high surface insulation resistance, is wash-free after welding, saves equipment and solvents, and is environmentally friendly.

The invention relates to a preparation method of a platinized copper powder lead-free soldering paste, and belongs to the technical field of material preparation.The method comprises the steps that copper powder with no oxide layer and a stannic chloride solution are mixed and stirred, the mixture is centrifuged, lower-layer precipitation is washed and dried to obtain activated copper powder, the activated copper powder and matter such as absolute ethyl alcohol are mixed and stirred, a platinum nitrate solution is dropwise added into the mixture, centrifugation is carried out, lower-layer precipitation is washed and dried to obtain platinized copper powder for use, rosin and matter such as ammonium cholate are mixed and heated to prepare scaling powder for use, the platinized copper powder and tin powder are mixed, the mixture is pressed into a blank, the blank is heated, cooled, subjected to ball milling and screened and then is mixed with the platinized copper powder and calcined, and therefore the lead-free soldering paste can be prepared.The surface insulation resistance of the prepared lead-free soldering paste is high and reaches 95*108-105*108 Ohm; by using the platinized copper powder lead-free soldering paste, the service life of a template is prolonged and can reach up to 9h.

The invention discloses high-performance halogen-free and lead-free soldering paste and a preparation method thereof. The halogen-free and lead-free soldering paste comprises, by mass percent, 80-90%of tin base alloy powder, 2-5% of hydroxy acid metal salt, 1-2% of acid alkyl phosphates, 0.2-1% of (1-hydroxyethylene) diphosphonic acid, 0.5-1.5% of polyaniline, 0.1-0.5% of amine antioxidants, 0.5-2% of rheological additives, 2-4% of film formers and 3-8% of hydrotropic agents. The soldering paste has high activity, low corrosivity and a few residues, the common problems such as periphery blackening after welding, too many tin beads and too many residues of current low temperature lead-free soldering paste can be well solved, the defective rate of printing is greatly reduced, and the reliability of welding is improved.

The invention discloses an impregnation liquid used in a copper clad plate preparation process, which comprises a first impregnation liquid and a second impregnation liquid, wherein the first impregnation liquid is formed by stirring and mixing a perfluoro-alkoxy concentrated dispersion and distilled water in a volume ratio of 1:1.4; and the second impregnation liquid is formed by evenly mixing a perfluoro-alkoxy concentrated dispersion, a polytetrafluoroethylene concentrated dispersion and distilled water in a volume ratio of 1:12:6. The dielectric loss factor of the copper clad plate with glass fiber cloth impregnated by the impregnation liquid disclosed by the invention is reduced from 1*<-3> to 7*10<-4>, the surface insulation resistance is raised from 1*10<10> to 10<15> on average, the bending strength is raised from 80 MPa to 120 MPa on average, and the peel strength is raised from 1.5kN/m to 2.3kN/m on average.

Belonging to the technical field of filling adhesive preparation, the invention particularly relates to an underfill adhesive with high surface insulation resistance and a preparation method thereof.The underfill adhesive disclosed by the invention does not adopt any flexibilizer or plasticizer, has the characteristics of low storage modulus, high glass-transition temperature, low hygroscopicity,good high and low temperature resistance, high surface insulation resistance under the conditions of high temperature and high humidity, etc., and ensures long-term reliable use of micro-sized densely packaged components in various environments.

The invention discloses a lead-free solder tin wire applicable to the drag soldering technology. The lead-free solder tin wire comprises the following components in percentage by weight: 96.0%-98.5% of lead-free solder and 4.0%-1.5% of scaling powder, wherein the scaling powder comprises the following components in percentage by weight: 1-4% of an organic solvent with a low boiling point, 4-10% of an activator, 0-0.5% of corrosion inhibitor and the balance of modified rosin. The lead-free solder tin wire can rapidly weld a component on a base plate, is high in tin breaking performance, does not cause the continuous tin phenomenon during the continuous application process, greatly improves the working efficiency, lowers the cost, does not contain the forbidden substances including RoHS2.0, REACH and the like, does not cause harm to the environment and meets the environmental protection requirement.