Abstract: The present invention provides a polybenzoxazole precursor, which comprises a structure of formula (I): wherein the definitions of Y, Z, R1, i, j, and V are provided herein. By means of the polybenzoxazole precursor, the resin composition of the present invention is able to form a film with high frequency characteristics and high contrast.

Abstract: A method is provided to fabricate a high-power module. A non-touching needle is used to paste a slurry on a heat-dissipation substrate. The slurry comprises nano-silver particles and micron silver particles. The ratio of the two silver particles is 9:1˜1:1. The slurry is pasted on the substrate to be heated up to a temperature kept holding. An integrated chip (IC) is put above the substrate to form a combined piece. A hot presser processes thermocompression to the combined piece to form a thermal-interface-material (TIM) layer with the IC and the substrate. After heat treatment, the TIM contains more than 99 percent of pure silver with only a small amount of organic matter. No volatile organic compounds would be generated after a long term of use. No intermetallic compounds would be generated while the stability under high temperature is obtained. Consequently, embrittlement owing to procedure temperature is dismissed.

Abstract: The present invention provides a polyimide comprising a structural unit, which comprises a first structural unit represented by formula (1) and a second structural unit represented by formula (2), wherein A, D and E are defined herein. A polyimide film formed by the polyimide has a low linear thermal expansion coefficient.

Abstract: A light metal joint filler is provided. The light metal joint filler is formed by uniformly mixing a solvent with a light metal powder and a silver powder, where a powder particle size of the light metal powder is on a micron scale, and a powder particle size of the silver powder is on a nanometer scale or a submicron scale. A metal joining method of the present disclosure includes: coating a joint of two to-be-joined light metal pieces with the light metal joint filler; and hot pressing the two to-be-joined light metal pieces, so that the silver powder is sintered and bonded with the light metal powder and surfaces of the two to-be-joined light metal pieces, and completing joining of the two to-be-joined light metal pieces after the silver powder is condensed.

Abstract: A method is provided to fabricate a high-power module. A non-touching needle is used to paste a slurry on a heat-dissipation substrate. The slurry comprises nano-silver particles and micron silver particles. The ratio of the two silver particles is 9:1˜1:1. The slurry is pasted on the substrate to be heated up to a temperature kept holding. An integrated chip (IC) is put above the substrate to form a combined piece. A hot presser processes thermocompression to the combined piece to form a thermal-interface-material (TIM) layer with the IC and the substrate. After heat treatment, the TIM contains more than 99 percent of pure silver with only a small amount of organic matter. No volatile organic compounds would be generated after a long term of use. No intermetallic compounds would be generated while the stability under high temperature is obtained. Consequently, embrittlement owing to procedure temperature is dismissed.

Abstract: A light metal joint filler is provided. The light metal joint filler is formed by uniformly mixing a solvent with a light metal powder and a silver powder, where a powder particle size of the light metal powder is on a micron scale, and a powder particle size of the silver powder is on a nanometer scale or a submicron scale. A metal joining method of the present disclosure includes: coating a joint of two to-be-joined light metal pieces with the light metal joint filler; and hot pressing the two to-be-joined light metal pieces, so that the silver powder is sintered and bonded with the light metal powder and surfaces of the two to-be-joined light metal pieces, and completing joining of the two to-be-joined light metal pieces after the silver powder is condensed.

Abstract: A method is provided to make a nano-silver paste. An organic acid is used as a protective agent. Silver nitrate is used as a source of silver ions to reduce silver nanoparticles on a surface protected by the organic acid. The particle size of the silver nanoparticle is 45 nanometers. In the other hand, a silver precursor of organic metal is synthesized. The organic metal is cracked at 200 celsius degrees (° C.) to fill pores left during sintering. After mixing the silver nanoparticle, the silver precursor and the solvent, the nano-silver paste is obtained. After being heated at 250° C. for 30 minutes, the nano-silver paste has a resistance of (3.09±0.61)×10?5 ?·cm. By being heated at 250° C. and applied with a pressure of 10 MPa to be hot-pressed for 30 minutes for joining copper to copper, the nano-silver paste obtains a bonding strength reaching 36 MPa.

Abstract: A method is provided to make a nano-silver paste. An organic acid is used as a protective agent. Silver nitrate is used as a source of silver ions to reduce silver nanoparticles on a surface protected by the organic acid. The particle size of the silver nanoparticle is 45 nanometers. In the other hand, a silver precursor of organic metal is synthesized. The organic metal is cracked at 200 celsius degrees (° C.) to fill pores left during sintering. After mixing the silver nanoparticle, the silver precursor and the solvent, the nano-silver paste is obtained. After being heated at 250° C. for 30 minutes, the nano-silver paste has a resistance of (3.09±0.61)×10?5 ?·cm. By being heated at 250° C. and applied with a pressure of 10 MPa to be hot-pressed for 30 minutes for joining copper to copper, the nano-silver paste obtains a bonding strength reaching 36 MPa.

Abstract: A method is provided to fabricate an electrolyte membrane. The membrane has an asymmetric structure and is a polybenzimidazole membrane doped with phosphoric acid. The asymmetric structure comprises a dense layer and a porous layer. The content of phosphoric acid introduced into the polybenzimidazole membrane reaches 20 phosphoric acid molecules per polymer repeating unit. The proton conductivity of the polybenzimidazole membrane reaches 5×10?2 siemens per centimeter (S/cm). An electrode made with the polybenzimidazole membrane can be smoothly operated in a proton exchange membrane fuel cell.

Abstract: A method is provided to fabricate an electrolyte membrane. The membrane has an asymmetric structure and is a polybenzimidazole membrane doped with phosphoric acid. The asymmetric structure comprises a dense layer and a porous layer. The content of phosphoric acid introduced into the polybenzimidazole membrane reaches 20 phosphoric acid molecules per polymer repeating unit. The proton conductivity of the polybenzimidazole membrane reaches 5×10?2 siemens per centimeter (S/cm). An electrode made with the polybenzimidazole membrane can be smoothly operated in a proton exchange membrane fuel cell.

Abstract: An enameled wire containing a nano-filler includes a metallic wire and at least one layer of insulating coating. At least one layer of the at least one layer of insulating coating includes a nano-filler. The nano-filler is a modified silicon dioxide slurry comprising silicon dioxide, organic solvent and organic silane coupling agent. The nano-filler comprises silicon dioxide modified with an organic silane coupling agent to improve dispersion of the nano-filler and maintain properties of the insulating coating. In addition, material and manufacturing costs of the enameled wire can be lowered.

Abstract: A nano-scaled antifouling paint for boat is fabricated. A few hydrophobic nano-particles are added into the paint to obtain a nanostructure and a low surface energy. Thus, sea creatures are hard to adhere on the boat or are easily removed. Moreover, owing to a low wettability of the paint, a water drag is reduced when the boat sails, and so fuel is saved.

Abstract: A method for fabricating a polybenzoxazole/clay nanocomposite material includes performing an ion exchange reaction between an organic amine and Na+-montmorillonite to form a swelled organoclay. A polycondensation reaction is conducted between two types of monomers, isophthaloyl chloride and 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane to form a polybenzoxaxole precursor polyhydroxyamide to form a PBO/clay composite material.

Abstract: A positive photosensitive resin composition of at least one uncapped polybenzoxazole precursor polymer, at least one capped polybenzoxazole precursor polymer, at least one photosensitive agent and at least one solvent, use of such compositions to pattern an image on a substrate and the resulting relied patterned substrates and electronic parts therefrom.

Abstract: A positive photosensitive resin composition of at least one uncapped polybenzoxazole precursor polymer, at least one capped polybenzoxazole precursor polymer, at least one photosensitive agent and at least one solvent, use of such compositions to pattern an image on a substrate and the resulting relied patterned substrates and electronic parts therefrom.

Abstract: A positive photosensitive resin composition of at least one uncapped polybenzoxazole precursor polymer, at least one capped polybenzoxazole precursor polymer, at least one photosensitive agent and at least one solvent, use of such compositions to pattern an image on a substrate and the resulting relied patterned substrates and electronic parts therefrom.

Abstract: A positive photosensitive composition and method of pattern formation using the same. The composition comprises a precursor of poly(imide-benzoxazole) (PIBO) copolymer prepared by the reaction of trimellitic anhydride halide monomer with bis(o-diaminophenol) monomer; a photosensitizer; and a solvent.

Abstract: The present invention relates to a positive-working photosensitive composition comprising a partially diazonaphthoquinone (DNQ) capped polyamic ester with a capping level of about 5-80 molar %; a photosensitive agent and a solvent. The composition shows a high photosensitivity and leaves a relief pattern with high resolution and low dark film loss.

Abstract: A method for fabricating a polybenzoxazole/clay nanocomposite material includes performing an ion exchange reaction between an organic amine and Na+-montmorillonite to form a swelled organoclay. A polycondensation reaction is conducted between two types of monomers, isophthaloyl chloride and 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane to form a polybenzoxaxole precursor polyhydroxyamide to form a PBO/clay composite material.

Abstract: The invention provides a poly(imide-benzoxazole) (PIBO) copolymer prepared from a trimellitic anhydride halide monomer and a bis(o-diaminophenol) monomer. The PIBO copolymer is characterized by the following recurring unit: wherein X is —O—, —S—, —C(CF3)2—, —C(CH3)2—, —CO—, —CH2—, —SO2—, —SO—, or deleted; and n is an integer. The PIBO copolymers of this invention are particularly useful as dielectric layers in semiconductor devices because they possess hydroxyl groups which create better adhesion to semiconductor substrates.