FBAR based duplexer device and manufacturing method thereof

Abstract

Disclosed herein is an FBAR based duplexer device and a manufacturing method thereof, which can achieve miniaturization, and reduction of a manufacturing cost and enhancement of a yield due to a simplified process. According to the present invention, first, a plurality of FBAR chips are prepared. Each of the FBAR chips comprises a substrate, air gaps 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. Then, a duplexer substrate having a duplexing circuit is prepared, and a plurality of the FBAR chips come into contact with the duplexer substrate. In this state, they are reversed so that the substrates of the FBAR chips face upward, and the bump balls are bonded to the duplexer substrate. After that, protective structures are formed by the use of a film, so as to be positioned on side surfaces as well as upper surface of the respective FBAR chips, and finally, a molding portion is formed so as to cover the protective structures.

1 - 6 . (canceled)  
     
     
         7 . An FBAR based duplexer device comprising: 
 a PCB substrate having a duplexing circuit;    a plurality of FBAR chips, each comprising an FBAR chip substrate, an air gap defined at a lower surface of the FBAR chip substrate, a piezoelectric layer unit formed under the air gap, a plurality of electrode pads provided at a lower side of the FBAR chip substrate so as to be electrically connected to the piezoelectric layer unit, and a plurality of bump balls formed on a lower side of the electrode pads so as to be bonded to an upper surface of the PCB substrate;    protective structures made of a film, the protective structures being laminated on the PCB substrate so as to cover side surfaces and upper surfaces of the respective FBAR chips; and    a molding portion formed on the PCB substrate so as to completely cover the protective structures.    
     
     
         8 . The device as set forth in  claim 7 , wherein the protective structures are made of an insulation film including a photosensitive polymer film and a non-photosensitive polymer film, and laminated on the PCB substrate by using a vacuum deposition.