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.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a duplexer device implemented by using a film bulk acoustic resonator (hereinafter, referred to as an FBAR), and a manufacturing method thereof, and more particularly to 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. [0003] 2. Description of the Related Art [0004] In recent years, wireless communication devices have tended to become much leaner, and enhanced and diversified in their quality and functions due to the development of the communication industry. This recent trend sincerely requires miniaturization and enhancement in quality related with various elements for use in the wireless communication devices. [0005] In order to satisfy such requirements to miniaturization, therefore, currently, active development is targeting studies f...

AI Technical Summary

Benefits of technology

The present invention provides an FBAR based duplexer device and a manufacturing method that can achieve miniaturization, cost reduction, and yield enhancement due to a simplified process. The method involves preparing a plurality of FBAR chips with electrode pads and bump balls, reversing them and bonding them to a duplexer substrate with protective structures. A molding portion is then formed to cover the protective structures. The duplexer substrate may be made of PCB sheets, and the protective structures may be made of insulation films. The technical effects of the invention include reducing the size of the duplexer device, reducing manufacturing costs, and increasing yield.

Problems solved by technology

In case that the FBARs 12 are formed with the protective structures, respetively, as stated above, however, the overall structure and manufacturing process of the FBARs 12 are disadvantageously complex, since the protective structures should be configured so as to be electrically connected to the device functional portions inside the FBARs 12, respectively, as well as protect the device functional portions.

Since the FBAR device can endure only about 30° C. during its bonding process, there is a considerable restriction in a sealing method for securing a good reliability.

Even when a large amount of the FBAR devices are produced through any precision processes, due to a complexity in process thereof, it is difficult to obtain an appropriate yield.

The LTCC technique, however, causes torsion of the LTCC substrate 15 during a LTCC firing process, resulting in a serious leak problem due to inferior bonding between the lead 17 and the LTCC substrate 15.

Further, due to the fact that the LTCC substrate 15 is formed by vertically laminating a plurality of the ceramic sheets, there is a high possibility of producing any defects in the LTCC substrate itself.

Although the above techniques have been achieved according to a most effective method for miniaturization, since a possibility of inferiority due to complex processes always exists, it is difficult to secure a profit margin required for mass production, causing an unnecessarily high manufacturing cost, and to increase a possibility of producing inferior products due to an operator's carelessness.

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