Abstract: A block copolymer of polyamide acid includes a first polyamide acid and a second polyamide acid alternately connected. The first polyamide acid is made by first dianhydride monomers and second diamine monomers. The second polyamide acid is made by second dianhydride monomers and first diamine monomers. Each first dianhydride monomer is or comprises a liquid crystal structure. Each second dianhydride monomer and each second diamine monomer respectively include a first flexible structure. Each first diamine monomer includes a liquid crystal structure. Each liquid crystal structure includes a cyclic group selected from a chemical structural formula of and intermediate groups selected from a chemical structural formula of Each flexible structure includes a group selected from a group consist of ether bond, ketone group, sulphone group, aliphatic hydrocarbon group, and any combination thereof.

Abstract: A polymer dispersion is disclosed. The polymer dispersion includes a liquid crystal polymer powder, a polyamide acid, and a solvent. A solid content of the polymer dispersion includes the liquid crystal polymer powder and the polyamide acid. The liquid crystal polymer powder has a mass ratio of 20% to 30% in the solid content. The polyamide acid has a mass ratio of 70% to 80% in the solid content. The polyamide acid is obtained by mixing two kinds of diamines and two kinds of dianhydrides together, causing the diamines and the dianhydrides to be polymerized with each other. Both two kinds of diamines and two kinds of dianhydrides comprise a liquid crystal structure and a flexible structure respectively. A method of preparing the polymer dispersion, and a method for preparing a polymer composite film using the polymer dispersion are also disclosed.

Abstract: A transparent polyimide mixture is disclosed. The transparent polyimide mixture includes a transparent polyimide, an additive, and a solvent. A molecular chain of the transparent polyimide includes an active hydrogen atom. The additive includes a carbodiimide group. An equivalent ratio of the active hydrogen atom and the carbodiimide group is in a range of 1:0.8 to 1:1.2. A method for preparing the transparent polyimide mixture, a transparent polyimide film, and a method for preparing a transparent polyimide film are also disclosed.

Abstract: A diamine monomer compound with reduced dielectric losses for better integrity and stability in digital transmissions is represented by a structural formula of wherein n1 is an integer greater than 1. A method for preparing the diamine monomer compound and a polyimide resin developed therefrom are disclosed. The diamine monomer compound introduces a long even numbered carbon chain and a liquid crystal unit structure, the long even numbered carbon chain giving flexibility, which reduces the regularity and rigidity of the molecular chain and facilitates film-forming processing. Dimensional stability is improved, and the coefficient of thermal expansion of the materials is reduced, the materials have good mechanical and heat-tolerant thermal properties, the loss factor and the coefficient of thermal expansion of the materials being reduced. A flexible film of the resin and an electronic device are also disclosed.

Abstract: A diamine monomer compound with a structural formula of wherein n1 is an integer greater than 1, forms the basis of a dielectric material with reduced dielectric losses for improved signals transmission. A method for preparing the compound, a polyimide resin made from the compound, a flexible film, and an electronic device including the polyimide resin are also disclosed. The compound has a long but flexible even numbered carbon chain and a liquid crystal unit structure. The reduced regularity and rigidity of the molecular chain make the polyimide resin convenient for film-forming. Dimensional stability is improved, the coefficient of thermal expansion of the materials is reduced, and the materials have good mechanical and thermal properties, the electron loss factor and coefficient of thermal expansion of the materials being reduced.

Abstract: A method for manufacturing a thick polyimide film includes providing a first and second laminated structures. The first and second laminated structures are heated, and the heated first and second laminated structures are wound together to form a third laminated structure. The first polyamic acid gel film of the heated first laminated structure and the second polyamic acid gel film of the heated second laminated structure are overlapped and bonded together to form a third polyamic acid gel film. Two third laminated structures are wound together to form a fourth polyamic acid gel film. A dehydration ring-closure imidization reaction is applied to the fourth polyamic acid gel film by heating to obtain the thick polyimide film. A thick polyimide film manufactured by the method is also disclosed.

Abstract: A transparent polyimide mixture is disclosed. The transparent polyimide mixture includes a transparent polyimide, an additive, and a solvent. A molecular chain of the transparent polyimide includes an active hydrogen atom. The additive includes a carbodiimide group. An equivalent ratio of the active hydrogen atom and the carbodiimide group is in a range of 1:0.8 to 1:1.2. A method for preparing the transparent polyimide mixture, a transparent polyimide film, and a method for preparing a transparent polyimide film are also disclosed.

Abstract: A polymer dispersion is disclosed. The polymer dispersion includes a liquid crystal polymer powder, a polyamide acid, and a solvent. A solid content of the polymer dispersion includes the liquid crystal polymer powder and the polyamide acid. The liquid crystal polymer powder has a mass ratio of 20% to 30% in the solid content. The polyamide acid has a mass ratio of 70% to 80% in the solid content. The polyamide acid is obtained by mixing two kinds of diamines and two kinds of dianhydrides together, causing the diamines and the dianhydrides to be polymerized with each other. Both two kinds of diamines and two kinds of dianhydrides comprise a liquid crystal structure and a flexible structure respectively. A method of preparing the polymer dispersion, and a method for preparing a polymer composite film using the polymer dispersion are also disclosed.

Abstract: A method for manufacturing a thick polyimide film includes providing a first and second laminated structures. The first and second laminated structures are heated, and the heated first and second laminated structures are wound together to form a third laminated structure. The first polyamic acid gel film of the heated first laminated structure and the second polyamic acid gel film of the heated second laminated structure are overlapped and bonded together to form a third polyamic acid gel film. Two third laminated structures are wound together to form a fourth polyamic acid gel film. A dehydration ring-closure imidization reaction is applied to the fourth polyamic acid gel film by heating to obtain the thick polyimide film. A thick polyimide film manufactured by the method is also disclosed.

Abstract: A polyimide film with improved dielectric and mechanical properties includes a polyimide layer with a liquid crystal structure which incorporates liquid crystal polymer powder. The polyimide layer is formed by a condensation reaction applied to dianhydride and diamine monomers, at least one of the dianhydride monomer and the diamine monomer having the liquid crystal structure. A method for manufacturing the polyimide film is also disclosed.

Abstract: A circuit board includes an insulating made by a low dielectric resin composition includes a low dielectric resin containing acid anhydride, an epoxy resin, polyphenylene ether resin with vinyl and active esters, maleic acid liquid polybutadiene, and an accelerator. Such low dielectric resin can be dissolved in organic solvent more easily than a low dielectric resin without acid anhydride, and the low dielectric resin containing acid anhydride has a better compatibility with other organic components than a low dielectric resin without acid anhydride. A low dielectric resin composition with lower dielectric constant and better properties can thus be obtained.

Abstract: A fluorine-containing dispersion is disclosed, the solid content of the fluorine-containing dispersion including a fluorine-containing polymer powder and polyimide. The fluorine-containing polymer powder has a mass ratio greater than 85% in the solid content, and the polyimide has a mass ratio less than 15% in the solid content. An average particle size of the fluorine-containing polymer powder is less than or equal to 3 ?m. A method of preparing the fluorine-containing dispersion, and a fluorine-containing composite film made using the fluorine-containing dispersion are also disclosed.

Abstract: A polyimide component being transparent includes a dianhydride monomer and a diamine monomer. The dianhydride monomer has an asymmetric structure. The dianhydride monomer has at least one first polar group and at least one side chain group. The first polar group is an ester group. A molecular structural formula of the side chain group is: The diamine monomer has an asymmetric structure and at least one second polar group. The second polar group is at least one of a nitrogen heterocycle and an ether group. The polyimide component is polymerized by the dianhydride monomer and the diamine monomer. The disclosure also relates to a polyimide film and a polyimide copper clad laminate.

Abstract: A liquid crystal polymer composition for a copper substrate with low dielectric constant and low dielectric loss suitable for use in printed circuit boards includes a solvent, a soluble liquid crystal polymer dissolved in the solvent, and a liquid crystal polymer powder dispersed in the solvent. The soluble LCP and the LCP powder form a solid content in the LCP composition. A mass ratio of the soluble LCP in the solid content of the LCP composition is in a range from 40% to 60%, and a mass ratio of the LCP powder in the solid content of the LCP composition is in a range from 40% to 60%.

Abstract: A circuit board includes an insulating made by a low dielectric resin composition includes a low dielectric resin containing acid anhydride, an epoxy resin, polyphenylene ether resin with vinyl and active esters, maleic acid liquid polybutadiene, and an accelerator. Such low dielectric resin can be dissolved in organic solvent more easily than a low dielectric resin without acid anhydride, and the low dielectric resin containing acid anhydride has a better compatibility with other organic components than a low dielectric resin without acid anhydride. A low dielectric resin composition with lower dielectric constant and better properties can thus be obtained.

Abstract: A block copolymer of polyamide acid includes a first polyamide acid and a second polyamide acid alternately connected. The first polyamide acid is made by first dianhydride monomers and second diamine monomers. The second polyamide acid is made by second dianhydride monomers and first diamine monomers. Each first dianhydride monomer is or comprises a liquid crystal structure. Each second dianhydride monomer and each second diamine monomer respectively include a first flexible structure. Each first diamine monomer includes a liquid crystal structure. Each liquid crystal structure includes a cyclic group selected from a chemical structural formula of and intermediate groups selected from a chemical structural formula of Each flexible structure includes a group selected from a group consist of ether bond, ketone group, sulphone group, aliphatic hydrocarbon group, and any combination thereof.

Abstract: A photosensitive resin composition comprises a modified polyimide polymer having a chemical structural formula of: photosensitive monomers, a bisphenol A epoxy resin, a photo-initiator, and a pigment. The modified polyimide polymer is made by a reaction of a polyimide polymer having a chemical structural formula of: and glycidyl methacrylate. The carboxyl group of the polyimide polymer reacts with the epoxy group of glycidyl methacrylate. The polyimide polymer is made by a reaction of dianhydride monomers each having an A group, diamine monomers each having the R group, diamine monomers each having the R1 group, and diamine monomers each having the R2 group. The diamine monomer having R group is a diamine compound having R group bonding with the carboxyl group. The diamine monomer having R1 group is a soft long-chain diamine monomer. R2 group comprises at least one secondary amine group or tertiary amine group.

Abstract: A polyamic acid composition is polymerized by dianhydride monomers and diamine monomers. A range of molar ratio of the dianhydride monomers to the diamine monomers is from 0.9 to 1.1. The diamine monomers have a combination of specific functional groups containing at least one nitrogen heterocycle structure, at least one liquid crystal structure, and at least one soft structure, wherein the diamine monomer containing nitrogen heterocycle structure has a molar weight percentage of 3% to 8% of a total molar weight of the diamine monomers, and the diamine monomers containing at least one liquid crystal structure and at least one soft structure have a molar weight percentage of 92% to 97% of the total molar weight of the diamine monomers. The disclosure further relates to a polyimide film, a copper clad laminate, and a printed circuit board.

Abstract: A low dielectric resin composition comprises a low dielectric resin containing acid anhydride, an epoxy resin, a rigid cross-linking agent, a soft cross-linking agent, and an accelerator. Such low dielectric resin can be dissolved in organic solvent more easily than a low dielectric resin without acid anhydride, and the low dielectric resin containing acid anhydride has a better compatibility with other organic components than a low dielectric resin without acid anhydride. A low dielectric resin composition with lower dielectric constant and better properties can thus be obtained. A film and a circuit board using such resin composition are also provided.

Abstract: A low dielectric polyimide composition comprises an aliphatic anhydride, a long chain diamine, and an ester diamine. A polyimide made of such low dielectric polyimide composition has low polarizability group, thus the dielectric constant of the polyimide is lower. A polyimide made of the low dielectric polyimide composition, a polyimide film using the polyimide, and a copper clad laminate using the polyimide film are also provided.