Arch Specialty Chemicals, Inc.

National Cheng-kung University

Industrial Technology Research Institute

Metal Industries Research & Development Centre

Microcosm Technology Co., Ltd

Steve Lien-Chung Hsu

Ahmad A Naiini

William D Weber

Pamela J Waterson

In-Gann Chen

Chang-Shu Kuo

Pamela D Waterson

Andrew J Blakeney

Sanjay Malik

Jinn-Shing King

Chia-Ming Yang

Shih-Jung Tsai

Li-Cheng Jheng

Chi-Wah Keong

Hung-Tao Chen

Jhy-Long Jeng

Yen-Ting Chen

Yu-Ching Lin

Yu-Chiao Shih

Keng-Chuan Chang

Hung-Cheng Chen

Po-I Lee

Yuan-Pin Huang

Hou-Chieh Cheng

The present invention provides a polybenzoxazole precursor, which comprises a structure of formula (I): wherein the definitions of Y, Z, R, 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.

Polybenzoxazole precursor and application thereof

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&#x2dc;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.

Method of fabricating high-power module

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.

Light metal joining method and joint filler for same

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 (&#xb0; 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&#xb0; C. for 30 minutes, the nano-silver paste has a resistance of (3.09&#xb1;0.61)&#xd7;10&#x3a9;&#xb7;cm. By being heated at 250&#xb0; 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.

Method of fabricating nano-silver paste having high bonding strength

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&#xd7;10siemens per centimeter (S/cm). An electrode made with the polybenzimidazole membrane can be smoothly operated in a proton exchange membrane fuel cell.

Method of fabricating proton-conducting electrolytic membrane

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.

Method for fabricating polybenzoxazole/clay nanocomposite materials

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.

Photosensitive resin compositions

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.

Positive working photosensitive composition, article and process for forming a relief pattern

Synthesis of poly (imide-benzoxazole) copolymer

A positive photosensitive resin composition comprising (a) a silane diol such as diarylsilane diol or dialkylsilane diol, (b) one or more polybenzoxazole precursors having the structure:

A heat resistant positive-working photosensitive composition that has a polybenzoxazole precursor bearing acid labile functional groups, a photoacid generator, a photosensitizer, and a solvent. The polybenzoxazole precursor bearing acid labile functional groups, has the structure: ##STR1## wherein k.sub.1 is an integer of 1 or 2, k.sub.2 is an interger of 0 or 1, and the sum of k.sub.1 and k.sub.2 is 2; Ar.sub.1 is a tetravalent aromatic, aliphatic, or heterocyclic group, or mixtures thereof; Ar.sub.2 is a divalent aromatic, aliphatic, or heterocyclic group or siloxane group; D is a monovalent acid labile group; and n is an integer from 20 to 200. A portion of Ar.sub.1 can be a divalent aromatic, aliphatic, or heterocyclic diamine moiety such that the fraction of diamine compound is 0-60 mole percent and the sum of diamine and diamino dihydroxy compound is 100%. Preparation of chemical amplification based positive-working, aqueous base developable photosensitive polybenzoxazole (PBO) precursors, the formulation of the resin composition, and the process for preparing heat-resistant relief structures from this resin composition. The positive photosensitive resin compositions are suitable especially for applications in microelectronics.

Photosensitive polybenzoxazole precursor compositions

A positive photosensitive resin composition comprising (a) a silane diol such as diarylsilane diol or dialkylsilane diol, (b) one or more capped polybenzoxazole precursors having the structure: ##STR1## wherein Ar.sub.1 is a tetravalent aromatic group, aliphatic group, heterocyclic group, or mixtures thereof; Ar.sub.2 is a divalent aromatic, heterocyclic, alicyclic, or aliphatic group that optionally may contain silicon; Ar.sub.3 is divalent aromatic group, aliphatic group, heterocyclic group, or mixtures thereof;

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Tainan, Taiwan

Steve Lien-Chung Hsu