Semiconductor devices provided with semiconductor chips are conventionally known (see Patent Document 1, for example). A semiconductor device of ball grid types such as a CSP (Chip Size Package) type or a BGA (Ball Grid Array) type has a plurality of bumps. Such a semiconductor device is mounted on a mounting substrate by bonding the bumps onto mounting pads formed on the mounting substrate (electrically and mechanically connected to the mounting substrate).
When such a semiconductor device is mounted on a mounting substrate, stress may be applied to the bumps. The bumps, when receiving stress, break due to fatigue, which blocks electrical conduction between the semiconductor chip and the mounting pads on the mounting substrate. Such a condition may cause a malfunction of the semiconductor device and is not desirable.
Patent Document 1: JP-A-2008-159949