Abstract: There is provided a semiconductor plastic package in the form in which at least one semiconductor chip is mounted on a small-sized printed wiring board, a metal plate for the above package and a method of producing a copper-clad board for the above package. More particularly, there is provided a semiconductor plastic package suitable for relatively high-watt, multi-terminal and high-density semiconductor plastic packages such as a microprocessor, a micro-controller, ASIC and graphic, and a method of producing the same.

Abstract: There are disclosed a nonwoven reinforcement for a printed wiring base board which nonwoven reinforcement contains a wet system nonwoven fabric constituted of thermotropic cystalline polyester fiber having a melting point of 290° C. or higher (component A) and a thermotropic cystalline polyester binder which has a melting point of 290° C. or higher and is in the form of a film having holes including at least 5 holes/mm2 each with an area of opening of 400 to 1000 &mgr;m2 (component B), the component A being fixed by the component B; a process for producing the above nonwoven reinforcement; a printed wiring base board produced from the above nonwoven reinforcement; and a printed wiring board produced from the above printed wiring base board. The nonwoven reinforcement and the printed wiring (base) board are excellent in various performances such as uniformity, dimensional stability, heat resistance and electrical characteristics such as dielectric constasnt and dielectric loss tangent.

Abstract: There is provided a semiconductor plastic package in the form in which at least one semiconductor chip is mounted on a small-sized printed wiring board, a metal plate for the above package and a method of producing a copper-clad board for the above package. More particularly, there is provided a semiconductor plastic package suitable for relatively high-watt, multi-terminal and high-density semiconductor plastic packages such as a microprocessor, a micro-controller, ASIC and graphic, and a method of producing the same.

Abstract: The invention is a process for making a cyanate ester resin cured product by (1) adding organic metal compound (a) and triethanol amine(b) to a cyanate resin composition which is flowable at a temperature of not more than 50.degree. C. comprising as its main component polyfunctional cyanate ester compound having at least two cyanate groups, thereby forming a cyanate resin composition having 0.1-5% by weight of (a) and 0.1-5% by weight of (b), which is flowable at a temperature of not more than 50.degree. C.; (2) molding the composition at a temperature of not more than 50.degree. C. (3) primary curing at a temperature of not more than 50.degree. C.; and (4) post-curing at a temperature of not less than 170.degree. C.

Abstract: An electrical laminate having an ability to absorb or shield ultraviolet rays having wavelength of 300-420 nm which comprises (i) at least one thermosetting resin-impregnated substrate, (ii) said substrate and a metal foil or (iii) said substrate, a metal foil and an adhesive layer for the metal foil comprising a thermosetting resin, characterized in that the thermosetting resin constituting part or all of said substrates or constituting said adhesive layer contains 0.2-6.0% by weight of a light absorber (A) on the basis of weight of the thermosetting resin, said light absorber is (a) an alkylthioxantone or a mixture of (a) said alkylthioxantone and (b) an ultraviolet rays-absorber.

Abstract: A method of drilling a through-hole in a printed circuit board panel, which comprises placing a water-soluble lubricant sheet on one surface or each of two surfaces of a printed circuit board panel and drilling a through-hole through the printed circuit board panel, the water-soluble lubricant sheet being composed of a mixture of 20 to 90% by weight of a polyethylene glycol having a weight average molecular weight of not less than 10,000 with 10 to 80% by weight of a water-soluble lubricant and having a thickness of 0.05 to 3 mm.

Abstract: A process for producing a multilayer printed wiring board, characterized in that copper surface of internal layer(s) is chemically oxidized, thereby forming a brown or black, oxidized copper surface on the internal layer board; and said oxidized copper surface of said internal layer board is treated with an acidic aqueous solution of a reducing agent containing at least one material selected from the group consisting of zinc formaldehyde sulfoxylate and sodium hypophosphite.

Abstract: A printed circuit board material composed of a reinforcing base material and a cured or uncured resin is disclosed, in which the base material is a fabric woven from hybrid yarns each of which is prepared from (I-1) at least one multifilament yarn made of glass fiber having a dielectric constant at 1 MHz of not higher than 5.5 or (I-2) at least one multifilament yarn made of heat resistant engineering plastic fiber having a dielectric constant at 1 MHz of not higher than 5.5 and (II) at least one yarn made of fluoroplastic long fiber and the thermosetting resin is a thermosetting resin whose dielectric constant after curing is not higher than 3.7. The material is excellent in dielectric properties and characteristics required for use in printed circuit board, such as heat resistance in soldering, flexural strength and peel strength of copper foil.

Abstract: A method for preparing a thin copper foil-clad substrate for the manufacture therefrom of circuit boards, which comprises subjecting a copper foil-clad circuit board substrate comprising an electrically insulating support having provided on one or both sides thereof a copper foil having an average thickness of 12 .mu.m or more to etching with an etching solution for copper, the etching being performed such that the whole surface of the copper foil is etched at a predetermined etching rate selected from the range of from 0.01 to 0.3 .mu.m/sec, thereby to reduce the thickness of the copper foil on at least one side of the insulating support to 10 to 80% of its original thickness, and the variation of the thickness of the copper foil remaining after the etching is within .+-.2.0 .mu.m on the basis of a desired thickness.

Abstract: A thermosetting resin composition polyfunctional cyanate ester resin composition comprising:(I) a cyanate ester compound selected from the group consisting of a polyfunctional cyanate ester having at least two cyanate esters in its molecule, a prepolymer of such a cyanate ester and mixtures thereof; and(II) at least one non-branched aromatic compound in an amount of 5-40% by weight of the total resin composition, said aromatic compound having a number-average molecular weight of 178-800, an average number of aromatic nuclei of 2-6, and a boiling point of more than 300.degree. C., and in which the portion having aromatic nuclei of 2-6 constitutes more than 50% is disclosed.

Abstract: A hot melt adhesive composition comprising (A) 99 to 80 wt % of a thermoplastic resin selected from the group consisting of a substantially amorphous thermoplastic saturated polyester resin, an ethylene-vinyl acetate copolymer and an ethylene-ethyl acrylate copolymer and (B) from 1 to 20 wt % of a monofunctional or polyfunctional cyanate ester compound having at least one cyanato group in the molecule is disclosed. The hot melt adhesive composition can further contain a co-modifier, a monofunctional or polyfunctional maleimide compound or a cross-linking catalyst for the thermoplastic resin (A). This composition has improved adhesive force, mechanical characteristics and heat resistance.

Abstract: A hot melt adhesive composition comprising (A) 99 to 80 wt % of a thermoplastic resin selected from the group consisting of a substantially amorphous thermoplastic saturated polyester resin, an ethylene-vinyl acetate copolymer and an ethylene-ethyl acrylate copolymer and (B) from 1 to 20 wt % of a monofunctional or polyfunctional cyanate ester compound having at least one cyanato group in the molecule is disclosed. The hot melt adhesive composition can further contain a co-modifier, a monofunctional or polyfunctional maleimide compound or a cross-linking catalyst for the thermoplastic resin (A). This composition has improved adhesive force, mechanical characteristics and heat resistance.

Abstract: A process for producing a polyfunctional cyanate ester polymer which comprises heating at least one polyfunctional cyanate ester compound having the formula:R--OCN).sub.mwherein m is an integer of at least 2 and R is one or more aromatic organic groups, and the cyanato groups are bonded to the arylene ring, in the presence of a catalytic amount of a dialkyl tin oxide having the formula:R.sup.1 R.sup.2 SnOwherein each of R.sup.1 and R.sup.2 is C.sub.1 -C.sub.30 alkyl is disclosed.

Abstract: A stabilized polyolefin resin composition in which (a) 0.005-5% by weight of at least one monofunctional or polyfunctional cyanate ester compound having at least one cyanato group in its molecule, (b) 0.01-5% by weight of at least one hindered amine ultraviolet absorber and (c) 0.005-2% by weight of at least one hindered phenolic antioxidant are incorporated into a polyolefin resin is disclosed. The resin composition has excellent heat stability and resistance to weathering.

Abstract: There is disclosed a thermosetting resin composition comprising a thermosetting cyanate ester resin composition (A) and a butadiene based copolymer (B)(i) or an epoxy resin-modified butadiene based copolymer (B)(ii), in which said component (B)(i) or (B)(ii) are used for modifying said component (A), component (A) and (B) being as follows;(A) a cyanate ester thermosetting resin composition comprising a cyanate ester compound selected from the group consisting of,(i) a polyfunctional cyanate ester having at least two cyanate group in its molecule,(ii) prepolymer of the cyanate ester of (i),(iii) coprepolymer of the cyanate ester of (i) and an amine, and(iv) mixtures thereof, and optionally adding another thermosetting resin,(B)(i) a butadiene based copolymer comprising a butadienaromatic vinytl monomer copolymer having 0.

Abstract: A method for producing a rigid resin mold for preparing plastic moldings which comprises:(1) preparing a composition (I) consisting essentially of(A) a cyanate ester resin composition, and(B-1) a metallic substance which does not substantially accelerate gelation of the cyanate ester resin composition (A),(2) preparing a composition (II) consisting essentially of(C) epoxy resin, and(B-2) a metallic substance which accelerates gelation of the cyanate ester resin composition (A) and does not substantially accelerate gelation of the epoxy resin (C) at temperatures below or equal to 100.degree. C.,(3) mixing composition (I) of step (1) and composition (II) of step (2) to form composition (III),(4) casting composition (III) of step (3) into a mold(5) and gelling the cast resin.

Abstract: An adhesive composition comprising at least(A) at least one cyanate ester compound selected from the group consisting of:(i) polyfunctional aromatic cyanate ester monomers having the formulaR--O--C.tbd.N).sub.nwherein n is integer of 2-10 and R is an aromatic organic group, the cyanate groups being bonded to an aromatic ring or said aromatic organic group;(ii) homoprepolymers of (i) and(iii) coprepolymer of (i) and an amine, and(B) at least one thermoplastic saturated polyester resin which is non-crystalline, substantially non-crystalline or of low crystallinity is disclosed. The adhesive composition has excellent heat resistance, moisture resistance and chemical resistance.

Abstract: An adhesive composition comprising at least(A) at least one cyanate ester compound selected from the group consisting of:(i) polyfunctional aromatic cyanate ester monomers having the formulaR--O--C.tbd.N).sub.nwherein n is integer of 2-10 and R is an aromatic organic group, the cyanate groups being bonded to an aromatic ring or said aromatic organic group;(ii) homoprepolymers of (i) and(iii) coprepolymer of (i) and an amine, and(B) at least one thermoplastic saturated polyester resin which is non-crystalline, substantially non-crystalline or of low crystallinity is disclosed. The adhesive composition has excellent heat resistance, moisture resistance and chemical resistance.

Abstract: A process for producing a curable resin liquid comprising: (a) at least one cyanate ester compound and (b) at least one polyfunctional maleimide compound, characterized in that the process comprises:(A) reacting at least one said maleimide compound with said diamine in the presence of a diluent at a temperature of 60.degree.-200.degree. C., the ratio of the maleimide group to the amine group being in the range of from 1:0.0015 to 1:0.3 to form a preliminary reaction product substantially free from amine group; and(B) mixing said preliminary reaction product with at least one cyanate ester compound ratio by weight of said preliminary reaction product to said cyanate ester compound is disclosed.

Abstract: A process for producing a curable resin which comprises reacting (a) at least one cyanate ester compound selected from the group consisting of polyfunctional cyanate esters having two or more cyanato groups per one molecule, prepolymers of the cyanate esters or mixtures thereof with (b) at least one compound having hydroxy group(s) and radical-polymerizable unsaturated double bond(s) in its molecule, the cyanate ester compound (a) and the compound (b) being used so that the ratio of the cyanato group to the hydroxy is in the range of from about 1:0.1 to about 1:2, in the presence of (c) a radical polymerization inhibitor at a temperature of about 80.degree.-about 140.degree. C.The curable resin produced according to the present invention is capable of giving cured products having excellent heat resistance and electrical properties.