Wiring board, method for manufacturing same, and semiconductor package

摘要

A wiring board in which lower-layer wiring composed of a wiring body and an etching barrier layer is formed in a concave portion formed on one face of a board-insulating film, upper-layer wiring is formed on the other face of the board-insulating film, and the upper-layer wiring and the wiring body of the lower-layer wiring are connected to each other through a via hole formed in the board-insulating film. The via hole is barrel-shaped, bell-shaped, or bellows-shaped.