HIGH-DENSITY THIN FILM WIRING BOARD AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a high-density thin film wiring board and its manufacturing method in which costs can be reduced while sufficiently performing its functions. SOLUTION: The high-density thin film wiring board have at least one thin film wiring layer on the first side of a substrate 6, and a conductive layer 8 in the lowermost layer of a thin film wiring layer which is in contact with the first side of the substrate. A hole 10 for electrical conduction between both sides of the substrate which passes through from the first side to the second side of the substrate with the conductive layer being exposed. The diameter of the hole 10 gradually increases from the first side toward the second side.