JPS5930314A - Surface acoustic wave device - Google Patents

Abstract

PURPOSE:To prevent the change in the characteristic due to temperature, by fitting a piezoelectric substrate to a holder with an elastic member. CONSTITUTION:The piezoelectric substrate is placed to a prescribed position of the holder 4 so that the back side of the piezoelectric substrate 1 formed with an interdigital electrode 2 may contact therewith. The piezoelectric substrate 1 is brought into press contact with the holder 4 by using the elastic member 6. The elastic member 6 is formed with a nickel plate or the like and formed to the folded into M shape so as to produce a pressure. Since the piezoelectric substrate 1 is slid with the holder even if each part is deformed because of temperature, the stable support is kept.

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a surface acoustic wave device, and particularly relates to a surface acoustic wave device in which a piezoelectric substrate is attached to a lyricist using an elastic member. be.

('b) Prior art and problems In conventional surface acoustic wave devices, an epoxy-based material is used to fix the piezoelectric substrate on which the interdigitated electrodes are formed and the holder on the opposite side of the surface where the surface waves propagate, that is, on the back surface. Adhesive etc. were applied to almost the entire surface and it was fixed to the cage. A perspective view of such a surface acoustic wave device is shown in FIG. In the figure, 1 is a piezoelectric substrate made of crystal or the like, 2 is a piezoelectric substrate, interdigitated electrodes formed on the clay, 8 is an adhesive member, and 4 is a lyricist made of metal such as iron (Fe)-nickel (Ni). It is.

An epoxy adhesive member 8 is applied to almost the entire surface of the back surface of the piezoelectric substrate 1 on which the interdigital electrodes 2 are formed, and is fixed to the holder 4. However, with this type of bonding method, distortion occurs due to mechanical stress during sealing of the lyricist 4 and distortion due to the difference in thermal expansion coefficient between the lyricist 4 and the piezoelectric substrate 1, resulting in fluctuations in the center frequency before and after sealing, and changes in temperature characteristics. There were various problems such as deterioration of frequency aging characteristics due to changes in stress over time, and deterioration of frequency aging characteristics. Therefore, as shown in FIG. 2, there is a method in which the piezoelectric substrate 1 is supported in a floating state via lead wires 5 above the lyricist 4, but this method requires the work of supporting the piezoelectric substrate 1 and connecting the lead wires 6. Each had their own problems, such as being difficult.

(0) Purpose of the Invention In view of the above-mentioned conventional problems, an object of the present invention is to provide a surface acoustic wave device in which a part of a piezoelectric substrate on which interdigital electrodes are formed is pressure-connected with an elastic member. be.

(C1) Structure of the Invention 1 In order to achieve the above-mentioned object, the present invention provides an elastic transducer having a configuration in which an input/output trannuducer consisting of interdigitated electrodes is formed on a piezoelectric substrate, and the piezoelectric substrate is attached to a holder. In the surface acoustic wave device, attachment of the piezoelectric substrate to the holder is achieved by pressing an elastic member into contact with the holder and fixing both ends of the elastic member to the holder.

(e) Embodiments of the Invention Hereinafter, embodiments of the surface acoustic wave device according to the present invention will be described in detail with reference to the drawings.

FIG. 8 is a perspective view for explaining one embodiment of the present invention.
Parts that are the same as the previous one are given the same symbols, and 6
7 is an elastic member made of metal such as nickel/l/(Ni), and 7 is a welding member to be bonded with solder or the like.

Hold gi? A cross-sliding electric current fi2 is formed at a predetermined position of I4, and the elastic member 6 and the piezoelectric substrate l are placed so that the back surfaces of the piezoelectric substrate l are in contact with each other with an adhesive or the like, and the piezoelectric substrate l is pressed into contact with the elastic member 6. However, the elastic member 6
Cut an elastic metal plate, such as a Ni plate, into a predetermined shape, bend the metal plate into an M-shape with a height corresponding to the thickness of the piezoelectric substrate 1, and bend both ends of the metal plate to the outside. While the elastic member 6 having a horizontal portion 61 bent horizontally is fitted so as to press the piezoelectric substrate 1, the horizontal portion 61 of the elastic member 6 is pressed against the retainer 4 and welded with solder or the like. It can be bonded using member 7.

FIG. 4 is a perspective view for explaining an embodiment of the music of the elastic member according to the present invention, and 8 is an elastic member formed by bending a metal such as Ni.

As is clear from the figure, by making the pressing portion 81 of the elastic member 8 flat, the contact area with the piezoelectric substrate 1 is increased, so that stable pressure contact can be achieved.

Note that if a recess into which the piezoelectric substrate 1 fits is formed in the holder 4, the piezoelectric substrate 1 can be supported more stably. Further, the horizontal portions of the elastic members 6 and 8 may be removably fixed without adhesive.

It may be fixed.

(0) Effects of the Invention As is clear from the above explanation, according to the surface acoustic wave device of the present invention, the piezoelectric substrate is pressure-bonded instead of adhering to the conventional one, so there is no influence on the deformation of the cage due to temperature, etc. Therefore, characteristic changes such as frequency changes can be prevented, which greatly contributes to improving the performance and reliability of the surface acoustic wave device.

[Brief explanation of the drawing]

1 and 2 are perspective views for explaining a conventional surface acoustic wave device, FIG. 8 is a perspective view for explaining an embodiment of the surface acoustic wave device according to the present invention, and FIG. 4 is a perspective view for explaining an embodiment of the surface acoustic wave device according to the present invention. FIG. 3 is a perspective view illustrating an example of the bending of the elastic member according to the present invention. In the figure, l is a piezoelectric substrate, 2 is a crossed finger electrode, 8 is an adhesive member, 4 is a holder, 5 is a lead wire, 6 and 8 are elastic members, 7 is a welding member, 61 is a horizontal part, and 81 is a suppressor. Each section is shown below. Figure 1) Figure 2 Figure 3 Figure 41 j忰7・□.

Claims (1)

[Claims] In a surface acoustic wave device configured such that an input/output trannuducer consisting of interdigital electrodes is formed on a piezoelectric substrate and the piezoelectric substrate is attached to a lyricist, the piezoelectric substrate is attached to the lyricist by pressure contact using an elastic member. A surface acoustic wave device characterized in that the elastic body member has both ends fixed to the holder.