To enable a larger number of bonding pads to be used without causing damage to a fine transistor and other IC devices.
An interposer 10 for electrically connecting a semiconductor die 50 to a board 70 is equipped with an interposition body 12 which is formed of a dielectric material and provided with a contacting surface 14 and an opposed bonding surface 16, contacting pads 18 arranged almost in the peripheral part of the contacting surface 14, bonding pads 20 arranged on nearly all the surface of the bonding surface 16, and conduction paths 22 each arranged inside the interposition body 12 as a whole so as to connect one of the contact pads to a corresponding bonding pad 20. Furthermore, in some cases, the interposer 10 includes a hermetically closed cooling groove 28 specified in the interposition body 12, fluid medium 30 almost filling up the groove 28, and a piezoelectric device which is fixed to the interposition body 12 so as to communicate with the cooling groove 28 and the fluid medium 30 and functionally coupled to at least the two conduction paths 22.
FRANK BURKE DEIPURATTSUA
J DAVIS BAKER
MARK ALAN STRAUB
VIVEK AMIIA JIAIRAZUHOI
