CONNECTION STRUCTURE BETWEEN WIRING LAYERS OF MULTI-LAYER CIRCUIT BOARD AND FORMATION OF THE CONNECTION STRUCTURE

摘要

PURPOSE:To provide a new wiring interlayer connection structure, which replaces a conventional through-hole system, to contrive a finer miniaturization of the metal wirings of a multilayer circuit board and the improvement of the mounting density of the metal wirings. CONSTITUTION:In a wiring interlayer connection structure of a multilayer-circuit board, wherein wirings provided via an insulator are connected to each other through a through hole to penetrate the insulator, the through hole 5 has an edge of roughly a linear form and at the same time, a slant face 6 formed into such a form that the thickness of the insulator is gradually decreased from the outside of the hole toward the inward of the hole is formed at the edge part. A plurality of the wirings 2, which are provided on the surface A on one side of the surfaces of the insulator 1, go down the face 6 and are extendedly provided in the hole 5, and a plurality of the wirings 3, which are provided on the other surface B of the insulator 1 and are extendedly provided in the hole 5, are connected to each other. Accordingly, the pitch between the wirings can be miniaturized to a degree of 100 or shorter to 50mum at a low-cost manufacturing cost.