JPS6181015A - Surface acoustic wave device - Google Patents

Abstract

PURPOSE:To obtain a small-sized surface acoustic wave device by forming a space with a top plate and a bottom plate to seal up input and output transducers consisting of comb-shaped electrodes on a piezoelectric substrate to which external connection terminals are joined. CONSTITUTION:A bottom plate 24 having a recessed part 19 where a piezoelectric substrate 8 is connected and stored and groove parts 20, 21, 22, and 23 on the bottom surface where external connection terminals 15-18 are held and adhered and stored is provided, and a top plate 25 is provided which is provided with a space in parts of input and output transducers 9 and 10 and the part of propagation of the surface wave between transducers 9 and 10 not to hinder propagation of the surface wave and protects said comb-shaped electrodes formed with an Al thin film or the like to secure the reliability and consists of an insulating material not to short-circuit external connection terminals 15-18, and this top plate 25 is adhered to the peripheral part of the bottom plate 24 to constitute the surface acoustic wave device.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a small and inexpensive surface acoustic wave device used in televisions and videos.

Conventional Structure and Problems Conventionally, this surface acoustic wave device has a surface acoustic wave element 1 mounted on an insulating substrate 2 with an adhesive 3, as shown in FIGS. 1 and 2. After wiring the electrode to the extraction electrode 5 using wire bonding 4 or the like, a cap 6 was attached using the adhesive 3, and then a resin mold 7 was applied.

In the conventional example as described above, there are a large number of component parts and a large number of assembly steps, making it impossible to provide the product at low cost and making it difficult to reduce the size.

Purpose of the Invention The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional surface acoustic wave. It is intended to provide devices.

Structure of the Invention In order to achieve the above object, the present invention has a structure in which an input/output transducer consisting of a comb-shaped electrode is placed on a piezoelectric substrate to which external connection terminals are bonded, and a space is formed using a top plate and a bottom plate and sealed. By doing so, a small-sized surface acoustic wave device can be provided.An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. First, an input transducer 9 and an output transducer 1o made of comb-shaped electrodes are provided on a piezoelectric substrate 8, and extraction electrodes 11, 12, 13.
14 to external connection terminal 15. i6 and 17.18 are joined by soldering or the like.

This makes an electrical connection.

A bottom plate 24 having a recess 19 for adhesively housing the piezoelectric substrate 8, grooves 20, 21, 22, and 23 extending over the bottom surface for sandwiching and adhesively housing the external connection terminals 15 to 18, and at least the input and output transducers. 9 and 10 and the transnuducers 9 and 10, where a surface wave propagates, a top plate 25 made of an insulator is attached to the periphery of the bottom plate 24 with an adhesive 26 to prevent short-circuiting of the table 18. It is made up of adhesive. Note that the external connection terminals 15~
18 is bent and stored along the grooves 20 to 23 of the bottom plate 24.

Effects of the Invention According to the surface acoustic wave device of the present invention, the number of components and people is reduced compared to conventional products.

There is no need for wire bonding to the lead-out electrodes connected to the output transducer and peripheral circuits, which greatly reduces manufacturing man-hours and can be provided at a much lower cost than conventional products. This makes it possible to make the device extremely compact and also contributes to the miniaturization of peripheral circuits.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional surface acoustic wave device, Fig. 2 is a top view showing the state in which the exterior of Fig. 1 is removed, and Fig. 3 is a cross-sectional view showing a conventional surface acoustic wave device.
The figure is a sectional view showing one embodiment of the surface acoustic wave device according to the present invention, and FIG. 4 is an exploded perspective view of the device. 8...Piezoelectric substrate, 9...Input transducer, 10...Output transducer, 15
, 16゜17.18... External connection terminal, 24.
...Bottom plate, 26...Top plate, 26...
·glue. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] An input transducer and an output transducer made of comb-shaped electrodes are provided on a piezoelectric substrate, external connection terminals are bonded to respective extraction electrodes of the input and output transducers, the piezoelectric substrate is adhesively housed, and the external connection terminal is held between the piezoelectric substrates. A surface acoustic wave device comprising: a bottom plate having a groove extending to the bottom surface of the transducer; and a top plate forming a space between the input and output transducers; and an external connection terminal bent and stored in the groove of the bottom plate.