THIN FILM CIRCUIT BOARD, MANUFACTURING METHOD THEREFOR, VIA FORMED SUBSTRATE AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a thin film circuit board or a via formed substrate of high reliability in which minute via plugs are formed with minute pitches. SOLUTION: An insulating film that acts as an etching stopper is formed on an Si substrate. Then a via hole is formed in the Si substrate by using a semiconductor process until the etching stopper film is exposed. Further, after a thin film circuit is formed on the insulating film, the insulating film in the via hole is removed to expose the thin film circuit. After the thin film circuit is thermally processed as necessary, the via hole is filled with a conductor, and a bump electrode is further formed.