Patent ID: 7267559

Claim:
An anisotropic conductive sheet, forming an electrical connection of electronic parts, comprising an insulating base material and a plurality of conductive passages embedded at predetermined positions in the insulating base material, penetrating the insulating base material in the thickness direction, wherein the insulating base material is a sheet-shaped material consisting of an insulating material selected from an insulating thermosetting resin, an insulating thermoplastic resin and an insulating ceramic material, the conductive passage comprises a matrix consisting of non-silicone material having rubber elasticity, the non-silicone material being filled into through-holes formed at a predetermined position in the base material, and a conductive filler dispersed in the matrix at an amount being hardened and retaining conductivity, the conductive filler being in a form of powder-shaped, bead-shaped, flake-shaped, needle-shaped or branch-shaped fine particles, wherein the non-silicone material filling the matrix and the conductive filler in the matrix are hardened and maintain a predetermined level of conductivity, and the conductive passages are formed at a pitch of less than 150 μm, and a surface layer made of conductive material capable of functioning as a contact is further provided on at least one of the end faces of the conductive passage, the surface layer is made of metal selected from the group consisting of gold, silver, copper, nickel and aluminum or an alloy of such metal, the surface layer comprises fine particles, the shape of which is broken-piece-shaped, bead-shaped, rod-shaped or lump-shaped, and the surface layer is constituted from the fine particles or an aggregated body of the same.