WIRING SUBSTRATE AND METHOD FOR MANUFACTURING WIRING SUBSTRATE

摘要

A wiring substrate comprises a wiring layer. Metal posts are arranged on the wiring layer. The metal posts are used to mount an electronic component. A protective layer covers a surface of the wiring layer on which the metal posts are arranged. The wiring layer comprises a seed layer and a metal plating layer. The metal plating layer has the same size as the size of the seed layer in a plan view. Each of the metal posts comprises an upper end, which protrudes from the protective layer, and a lower end, which has the same width as the width of the upper end or wider. The protective layer comprises a fillet for each metal post. The fillet extends toward an upper end surface of a corresponding metal post and comes in contact with a side surface of the corresponding metal post.