JPH0442603A - Surface acoustic wave device - Google Patents

Abstract

PURPOSE:To prevent a sealing resin material from giving adverse effect on the propagation of a surface acoustic wave to a surface acoustic wave element by sealing the surface acoustic wave element provided with a frame pattern formed around a propagation path of a surface acoustic wave generated from a transducer and with a film arranged on the frame pattern to cover the propagation path by means of the resin material. CONSTITUTION:The device is provided with a surface acoustic wave element A with a transducer 10 and a pad 11 formed thereto, a frame pattern 12 formed around a propagation path of a surface acoustic wave generated from the transducer 10 and a film 13 arranged on the frame pattern 12 to cover the propagation path. Then the element A provided with the frame pattern 12 and the film 13 is sealed by the resin member 15. Since the sealing resin material 15 is not in contact with the surface of the surface acoustic wave element, the material 15 has no adverse effect on the propagation and since the device is formed as the resin sealing package, the productivity is improved and the cost is reduced because of the adoption of the resin package.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a surface acoustic wave device, and particularly to a sealing structure for a surface propagation path of a surface acoustic wave element.

[Summary of the Invention] The present invention forms an insulating layer to cover the propagation path of a surface acoustic wave element, leaves a free space between the propagation path surface and the insulating layer, and thereby enables resin sealing. This is what I did.

[Prior Art] Due to the function of a surface acoustic wave element, the presence of a foreign material layer on a surface through which surface waves propagate adversely affects the propagation of surface waves and impairs desired characteristics.

Therefore, measures have been taken to house the surface acoustic wave device in a package, but in this case, the resin sealing means used in ICs etc. cannot be applied, and the hermetic seal (air-sealing) using a metal or ceramic package is not applicable. A sealing means called a hermetic structure (sealing structure) is often used. 7th
The figure shows a typical hermetic seal, where l is a base, A is a surface acoustic wave element, 2 is an adhesive, 3 is a cap, 4 is a lead, and 5 is a bonding wire.

[Problem to be solved by the invention] The hermetic sealing structure using the metal package or ceramic package described above is higher in cost and lower in productivity than the resin sealing structure, so it is difficult to reduce costs and improve production efficiency. It has been demanded.

C. Object of the Invention] An object of the present invention is to provide a surface acoustic wave device that can be sealed with a resin without causing any adverse effects on the propagation of surface waves.

[Means for Solving the Problems] A surface acoustic wave device according to the present invention includes a surface acoustic wave element in which a transducer and a pad are formed, and a surface acoustic wave propagation path generated by the transducer on the element. A configuration consisting of a rod-shaped pattern formed around the periphery, a film disposed on the frame-shaped pattern so as to cover the propagation path, and a resin member that seals the element provided with the frame-shaped pattern and the film. It has the following characteristics.

[Production] In the surface acoustic wave device with the above configuration, the propagation surface of the element is held in a hollow shape by the frame pattern and the film, so even if it is sealed with resin, the propagation of surface waves is prevented. not be hindered.

[Example 1] Figures 1 to 6 show an example of the present invention.

FIG. 1 shows the overall structure of the surface acoustic wave device, and FIGS. 2 to 6 show partial structures during the manufacturing process.

First, on the surface acoustic wave element A, as shown in FIGS. 2 and 3, the comb-shaped electrode IO and the bonding pad 11 of the transducer are formed by well-known photolithography.

Next, as shown in FIG. 4, a frame-shaped pattern 12 is formed by photolithography so as to surround the comb-shaped electrode 10 and the surface wave propagation path. The bonding pad 11 is located outside the frame pattern 12. This frame pattern 12
For example, insulating resin such as polyimide resin is used. These processes are performed in the wafer state.

After forming the frame pattern 12, a predetermined process is performed to form a chip. In this state, as shown in FIG. 5, a strip-shaped insulating film 13 is placed on the frame pattern 12. , joined by heating or pressure. In this way, on the element A, the surface wave propagation region is surrounded by the insulating layer with the bonding pad 11 on the outside, and as shown in FIG.
It becomes 4.

The element A having the hollow portion formed on its surface as described above is subjected to the same assembly process as a normal IC, and is resin-sealed with a resin material 15 as shown in FIG. 1st [middle, 1
6 is a base, 17 is an adhesive, 18 is a bonding wire, and 19 is a lead.

According to the above configuration, the sealing resin material 15 does not come into contact with the surface of the surface acoustic wave element, and therefore does not adversely affect the propagation.

[Effects of the Invention] As described above, according to the present invention, the package of the surface acoustic wave element can be configured as a resin-sealed package, so that productivity can be improved and costs can be reduced by using the resin package.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a surface acoustic wave device showing an embodiment of the present invention, FIG. 2 is a plan view of a surface acoustic wave element, and FIG. 3 is an enlarged sectional view of a part of the surface acoustic wave device. The figure is a plan view of the element showing the manufacturing process, FIG. 6 is an enlarged sectional view of a part of FIG. 5, and FIG. 7 is a longitudinal sectional view of a conventional surface acoustic wave device. A...Surface acoustic wave element, 10...
......Comb-shaped electrode, 11......Ponding pad, 12......Frame-shaped pattern, 13.
......Film, 14...Hollow part, 15...Sealing resin material, Yu6...
......Base, 17...Adhesive, 18...Bonding wire, 19.
・・・・・・・・・Lead. Patent Applicant Clarion Co., Ltd. Agent Patent Attorney Nagai 1) Take 3 Part IIA Figure 1g7

Claims (1)

[Claims] a surface acoustic wave element on which a transducer and a pad are formed; a frame-shaped pattern formed around a surface acoustic wave propagation path generated by the transducer on the element; and a frame-shaped pattern formed on the frame-shaped pattern so as to cover the propagation path. 1. A surface acoustic wave device comprising: a film disposed in the frame pattern; and a resin material sealing the frame pattern and the element provided with the film.