Patent ID: 6946320

Claim:
A method for manufacturing an FBAR based duplexer device comprising the steps of: a) preparing a plurality of FBAR chips, each FBAR chip comprising a substrate, air gap and piezoelectric layer unit, which are successively arranged, a plurality of electrode pads electrically connected to the piezoelectric layer unit, and bump balls formed on the electrode pads in a one to one ratio; b) preparing a duplexer substrate having a duplexing circuit; c) reversing a plurality of the FBAR chips after contacting them with the duplexer substrate so that the substrates of the FBAR chips face upward, and bonding the bump balls to the duplexer substrate; d) forming protective structures by the use of a film, the protective structures being positioned on side surfaces as well as an upper surface of the respective FBAR chips; and e) forming a molding portion on the duplexer substrate so as to cover the protective structures.