Abstract: A lower chip is fixed to a surface of an interposer by flip-chip bonding with an under fill acting as an adhesive applied to the surface. A lifted pad having a height of approximately 10 ?m is provided on the surface of the interposer. A bonding wire connects the lifted pad and a bonding pad provided on a surface of an upper chip. A stick-out portion of the under fill at the time of fixing the lower chip to the interposer is dammed by the lifted portion of the lifted pad. This prevents the stick-out portion of the under fill from covering the top of the lifted pad.

Abstract: A semiconductor device includes a semiconductor chip, solder balls, a printed wiring substrate on which the semiconductor chip is provided and which serves to electrically connect the semiconductor chip and the solder balls. When such a semiconductor device is mounted on a motherboard, at least one through-aperture is in advance formed on the printed wiring substrate oppositely to the semiconductor chip. After the solder balls are soldered to the motherboard, an under-filler is introduced from either of a space between the semiconductor chip and the printed wiring substrate or a space between the printed wiring substrate and the motherboard, thus flowing from one space into the other space via the through-aperture.