JPH01196905A - Surface acoustic wave device - Google Patents

Abstract

PURPOSE:To improve the reliability and to simplify the assembling process by leading out an input/output electrode arranged on the plate face of a piezoelectric substrate to its end, forming an external electrode onto the plate face of a base corresponding to the lead electrode and adhering the lead electrode to an external electrode of the base by a conductive adhesives. CONSTITUTION:An external electrode 12 is formed by means of metallizing, etc., on the plate face of the base 1 made of an insulation material such as a ceramic. On the other hand, an electrode 4 of surface acoustic wave resonator type formed onto the plate face of a piezoelectric substrate 3 is led out to a side end face of the piezoelectric substrate 3 by an electrode 11. Then the leadout electrode 11 is connected electrically to an outer electrode 12 of the base 1 by using a conductive adhesives 13, for example, and kept mechanically. Thus, the electric connection of the electrode and the mechanical holding of the piezoelectric substrate are implemented simultaneously, the process is reduced and the thin metallic wire is not exposed externally, then no damage is incurred during the handling in the process and the reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a surface acoustic wave device with a simplified morning stand-up process.

(Technical background of the invention and its problems) Conventionally, surface acoustic wave devices have been known in which surface acoustic waves are propagated by forming, for example, SAW resonator-shaped electrodes on a piezoelectric substrate made of niobium oxide, quartz, or the like. ing.

FIG. 2 is a perspective view showing an example of a conventional surface acoustic wave device of this type, in which a pair of terminals 2.2 are implanted in a metal base 1 insulated with a hermetic glass or the like.

On the other hand, on the surface of the piezoelectric substrate 3 made of crystal, niobium oxide, etc., for example, a SAW as shown in the figure is installed.

A child-shaped electrode 4 was formed, and the substrate 3 was die-bonded to the base 1 using an adhesive 5 such as resin.

Then, the SAW resonator type electrode 4 and the terminal 2.2
A thin metal wire 6 is used to connect the tip of the metal wire 6 to the tip of the metal wire 6, for example, by wire bonding.

However, such a device requires a process of die bonding the piezoelectric substrate 3 to the base l and a wire bonding process of connecting the SAW resonator-shaped electrode 4 to the terminal 2, resulting in two steps and high cost. There was a problem.

Furthermore, when wire bonding is performed, the thin metal wires 6 are exposed, so careful handling during the process is required, and even with this method, accidents that damage the thin metal wires 6 cannot be avoided.

(Object of the Invention) The present invention has been made in view of the above circumstances, and has an elastic surface that can reduce the number of man-hours, is easy to handle in the process, and can improve product reliability. The purpose is to provide a wave device.

(Summary of the invention) Input/output electrodes that excite surface acoustic waves are arranged on the plate surface of a piezoelectric substrate, and the input/output electrodes are drawn out to the ends, and external electrodes are formed on the plate surface of the base in correspondence with the extracted electrodes. death,
This extraction electrode is fixed to the external electrode of the base with a conductive adhesive to electrically connect and mechanically hold it.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to a perspective view shown in FIG. 1, in which the same parts as in FIG. 2 are given the same reference numerals.

In the figure, reference numeral 1 denotes a base made of an insulating material such as ceramic, and external electrodes 12 are formed on the plate surface by metallization or the like.

On the other hand, a SAW resonator-shaped electrode 4 formed on the plate surface of the piezoelectric substrate 3 is led out to the side end surface of the piezoelectric substrate 3 by an extraction electrode 11.

Then, this extraction electrode 11 is connected to the external electrode 12 of the base l.
For example, the conductive adhesive I3 is used to electrically connect and mechanically hold.

With such a configuration, the electrical connection of the electrodes and the mechanical holding of the piezoelectric substrate can be performed at the same time, shortening the process, and since the thin metal wires are not exposed to the outside, Reliability can be improved without being damaged during handling.

It should be noted that the present invention is not limited to the above embodiments; for example, the base l may be made of an insulating material such as glass, or an insulating film may be formed on the surface of a metal plate. .

Furthermore, the electrodes formed on the piezoelectric substrate are not limited to SAW co-photograph type electrodes, and it is possible to form appropriate electrodes that receive surface acoustic waves in this way. It is not limited.

In addition, in the above embodiment, the extraction electrode led out to the side end of the piezoelectric substrate and the external electrode of the base are connected with a conductive adhesive, but if the thickness of the piezoelectric substrate is thin, the end The extraction electrodes drawn out onto the surface may be connected using a conductive adhesive.

Furthermore, it is preferable that the lead-out direction of the extraction electrode be perpendicular to the propagation direction of the surface acoustic wave on the piezoelectric substrate, since this does not impair the propagation characteristics of the surface acoustic wave.

(Effects of the Invention) As described in detail above, according to the present invention, it is possible to provide a surface acoustic wave device that can simplify the assembly process and improve reliability.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a perspective view showing an example of a conventional surface acoustic wave device. l... Base 3... Piezoelectric substrate 4... SAW resonator-shaped electrode 11... Leading electrode 12... External electrode 13... Conductive adhesive

Claims (4)

[Claims] (1) A piezoelectric substrate in which input and output electrodes for exciting surface acoustic waves are arranged on the plate surface, and these input and output electrodes are led out to the ends as extraction electrodes, and external electrodes are formed on the plate surface in correspondence with the extraction electrodes. A surface acoustic wave device comprising: a base; and a conductive adhesive that fixes and electrically connects the extraction electrode to an external electrode of the base and mechanically holds the extraction electrode. (2) The surface acoustic wave device according to claim 1, wherein the base is made of ceramic. (3) The surface acoustic wave device according to claim 1, wherein the base has a metal surface coated with an insulating film. (4) The surface acoustic wave device according to claim 1, wherein the extraction electrode is led out in a direction perpendicular to the propagation path of the surface acoustic wave.