Abstract: A substrate for a laminate which comprises a nonwoven fabric which is composed mainly of a liquid crystal polyester fiber, and which is subjected to (1) an entangling treatment, (2) a heating treatment to impart adhesivity to a thermosetting resin, and (3) a surface-modifying treatment, and a laminate containing at least one prepreg prepared by impregnating the substrate with a thermosetting resin and drying are disclosed. The substrate of the present invention has low dielectric constant, is light, exhibits low hygroscopicity, and has good properties to be impregnated with the thermosetting resin and good adhesiveness to the thermosetting resin.

Abstract: A method of drilling a through-hole for inter-surface conduction in a laminate for a printed wiring board, in which the heat generation in a drill bit can be inhibited in drilling holes, quality holes can be highly efficiently made in the presence, on the laminate surface, of a novel water-soluble lubricant sheet which has high strength and can be handled easily, the method comprising drilling the through-holes in the presence of a water-soluble lubricant sheet which has a thickness of 0.02 to 3 mm and is formed from a mixture of 20 to 90% by weight of a polyether ester with 10 to 80% by weight of a water-soluble lubricant.

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 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 photo-curable resin composition is disclosed comprising (i) a mixture and/or a preliminary reaction product of (a) at least one cyanate compound selected from the group consisting of polyfunctional cyanate esters, prepolymers of the cyanate esters, coprepolymers of the cyanate esters and an amine and mixtures thereof, (b) at least one compound selected from the group consisting of monomers having at least one olefinically double bond prepolymers of the monomers, liquid rubbers having one or more acryloyl or methacryloyl groups and mixtures thereof and optionally (c) at least one maleimide compound selected from the group consisting of polyfunctional maleimides, prepolymers of the maleimides, coprepolymers of the maleimides and an amine and mixtures thereof and (ii) a photo polymerization initiator or a photo sensitizer.