Patent ID: 6949990

Claim:
A filter device comprising: a filter element that has a plurality of piezoelectric thin-film resonators arranged in series arms end parallel arms; and a package that houses the filter element in a face-down state, the filter element and the package being electrically connected to each other through bumps, the package having a plurality of first pad parts on which the bumps are placed, and a plurality of transmission paths that electrically connect the first pad parts to the outside, the filter element having a plurality of second pad parts that are electrically connected to the first pad parts through the bumps, and a plurality of wiring parts that electrically connect the second pads to the piezoelectric thin-film resonators and electrically connect the piezoelectric thin-film resonators to one another, and inductances formed with the transmission paths being connected in series to the piezoelectric thin-film resonators, wherein the area of each of the first pad parts is one to six times larger than the placement area of each corresponding one of the bumps, and wherein the transmission paths are formed under the filter element on a die-attach face of the package.