Patent ID: 7088983

Claim:
A semiconductor device for a radio communication device in which a signal is received or transmitted a signal after frequency-conversion between frequency bands, the frequency bands including a first frequency band and a second frequency band that is higher in frequency than the first frequency band, wherein a semiconductor device for a radio communication device comprises: a base band chip having a low-frequency signal processing unit for processing a signal in the first frequency band; and a plurality of high-frequency chips piled up on and bonded to the surface of the base band chip, and having high-frequency signal processing units for processing a signal in the second frequency band, the high-frequency chips being electrically connected to the base band chip without any matching circuits interposed between the base band chip and the high-frequency chips, wherein the high-frequency chips are disposed with the surfaces of the high-frequency chips opposite to the surface of the base band chip, and are connected to the base band chip by inter-chip connection members interposed between the opposite surfaces, wherein the inter-chip connection members include metal projections on the surface of at least one of the base band chip and the high-frequency chips, the metal projections having a height that is smaller than the height of a bump, wherein interconnections between the high-frequency chips are made via metal wiring on the surface of the base band chip, and wherein the metal projections and the metal wiring are both formed of non-oxidizable metal films.