Method of manufacturing ball grid array type semiconductor device

A BGA type semiconductor device having high reliability is offered. A pad electrode is formed on a surface of a semiconductor substrate and a glass substrate is bonded to the surface of the semiconductor substrate. A via hole is formed from a back surface of the semiconductor substrate to reach a surface of the pad electrode. An insulation film is formed on an entire back surface of the semiconductor substrate including an inside of the via hole. A cushioning pad is formed on the insulation film. The insulation film is removed from a bottom portion of the via hole by etching. A wiring connected with the pad electrode is formed to extend from the via hole onto the cushioning pad. A conductive terminal is formed on the wiring. Then the semiconductor substrate is separated into a plurality of semiconductor dice.