Patent ID: 8497163

Claim:
A method for fabricating a circuit device, the method comprising: preparing a semiconductor substrate and a wiring substrate, wherein an element electrode is provided on one main surface of the semiconductor substrate and wherein a metallic sheet is provided on one main surface of the wiring substrate, whereas a substrate electrode corresponding to the element electrode is provided on the other main surface thereof; and turning the metallic sheet into thin film such that the thickness of the metallic sheet is substantially equal to that of the wiring layer, the method further comprising: a first press-bonding process of bonding together the semiconductor substrate and the wiring substrate at a first temperature applied thereto such that the element electrode connects to the substrate electrode, the first press-bonding process being performed after the preparation process and before the thinning process; and a second press-bonding process of press-bonding the semiconductor substrate and the wiring substrate, which have been bonded together at the first temperature, at a second temperature that is higher than the first temperature, the second press-bonding process being performed after the thinning process.