Surface acoustic wave device and manufacruring method thereof

Abstract

In the surface acoustic wave device including a lead frame made of metal in which a plurality of inner leads 9 are formed, wherein a chip 1 comprising at least one piezoelectric substrate is mounted on a resin base 3 into which a lead frame is molded integrally, are provided a wire lead section metal surface 7a that is formed by exposing a wire lead section 7, which is electrically connected with an electrode of the chip through a bonding wire 4, out of inner leads that are arranged on both sides of the chip, from the resin base, and a chip lead section metal surface 10a that is formed by exposing a chip lead section 10, which is partially covered with the chip, from the resin base.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a surface acoustic wave device such as a resonator, a filter and so forth that is housed in a mobile communication apparatus such as a mobile telephone and so forth. More particular, the present invention relates to a package structure and a manufacturing method of the surface acoustic wave device. [0002] Conventionally, for the surface acoustic wave device, a ceramic package for surface mounting, and a metal package by cold weld or electro-deposition have been employed. [0003]FIG. 11 is a view illustrating a section of the surface acoustic wave device using the conventional ceramic package. [0004] As shown in this Fig., in general, for the ceramic package is employed a multi-layer structure of a first ceramic layer 118, a second ceramic layer 119, and a third ceramic layer 120. [0005] Further, in order to cover a top portion thereof with a cap 122, a metal ring 121 was brazed. [0006] In such a multi-layer ceramic p...

AI Technical Summary

Benefits of technology

The present invention provides a surface acoustic wave device that increases attenuation volume in the high-frequency attenuation band, reduces stress on the printed circuit board, and improves production efficiency. The device includes a lead frame made of metal with a chip mounted on a resin base. The lead frame has inner leads that are disposed on both sides of the chip, and a wire lead section metal surface that is exposed on one side of the chip. The device also includes a chip lead section metal surface on both sides of the chip, which increases the degree of freedom of the connection of the bonding wire. The device is designed to be compact, lightweight, and cost-effective.

Problems solved by technology

In the surface acoustic wave device using the above-mentioned ceramic package, however a first problem exists that low pricing is difficult.

Also, this is because, as to the sealing method, in the case of the seam welding, it is necessary to braze the metal ring 121 on the ceramic, and also in the case of the solder sealing, it is unavoidable to prepare a special solder lid.

In the surface acoustic wave device disclosed in JP-A-63495 / 1993, however, a third problem exists: it is necessary to cover with an insulating film from the inside of the device the periphery of the peripheral unit of which the internal surface is a conductive layer, or of the lead wire that is caused to pass through the peripheral unit that is formed of the conductive resin, whereby the production process increases and low pricing of the surface acoustic wave device is difficult.

Further, in the SIP-shape surface acoustic wave device disclosed in JP-A-63495 / 1993 and JP-A-188672 / 1994, a fourth problem exists: This is inclined when mounted on a printed circuit board, stress such as distortion of the printed circuit board and so forth has an influence over characteristics of the surface acoustic wave device, or unification of the surface-mounting surface acoustic wave device using the conventional ceramic package and the printed circuit board is impossible, whereby the specific printed circuit board becomes necessary.

Further, in the SIP-shape surface acoustic wave device disclosed in JP-A-63495 / 1993 and JP-A-188672 / 1994, in order to support the chip comprising the piezoelectric substrate, it was illustrated that it was fastened to and mounted on the lead frame; however a fifth problem exists that it is not suitable for downsizing.

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