JPH0918278A - Piezoelectric resonator and piezoelectric parts using the resonator - Google Patents

Abstract

PURPOSE: To prevent self-welding between an Ag electrode provided on the surface of a piezoelectric material substrate and a metallic terminal whose surface an Ag film brought into contact with this Ag electrode is provided on. CONSTITUTION: Fine particles 4 having a high melting point are stuck on oscillation electrodes 3 which are provided on front and rear faces of a piezoelectric material substrate 2 and consist of Ag. Ceramics such as an alumina, glass, Ni, Cr, W, Ti, Mo, Ni-Cu (monel), or alloys of these metals are used as materials of these fine particles 4. These fine particles 4 having a high melting point are stuck to or buried in the surface of the oscillation electrode 3 by the sand-blast method, the agitation method, or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonator, and more particularly to a piezoelectric resonator used when constructing an oscillation circuit, a filter circuit and the like, and a piezoelectric component using this piezoelectric resonator.

[0002]

2. Description of the Related Art As one type of piezoelectric component, one having a structure including a piezoelectric resonator and a metal terminal for holding the piezoelectric resonator is known. The piezoelectric resonator has a piezoelectric substrate and vibrating electrodes and extraction electrodes provided on the front and back surfaces of the piezoelectric substrate. These vibrating electrodes and extraction electrodes are usually made of Ag. On the other hand, the metal terminal is obtained by providing an Ag film on the surface of a plate material such as phosphor bronze by means such as plating. Then, the metal terminal is brought into contact with the vibrating electrode or the extraction electrode, and the piezoelectric resonator is held by the metal terminal.

[0003]

In the conventional piezoelectric component, both the vibrating electrode and the extraction electrode of the piezoelectric resonator and the surface coating film of the metal terminal are made of Ag. However, because Ag has a property of easily self-bonding,
Fusing may occur at the portion where the metal terminal is in contact with the vibrating electrode or the extraction electrode. In such a case, vibration energy generated when the piezoelectric resonator resonates is applied to the fusion-bonded portion of the metal terminal and the vibrating electrode, part of the vibrating electrode is peeled off from the piezoelectric substrate, and the vibrating electrode and the metal terminal There was a risk of poor continuity.

Therefore, an object of the present invention is to provide a piezoelectric resonator in which an Ag electrode provided on the surface of a piezoelectric substrate and a metal terminal provided with an Ag film contacting the Ag electrode on the surface are less likely to be fused together, and this piezoelectric resonance. It is to provide a piezoelectric component using a child.

[0005]

In order to achieve the above objects, a piezoelectric resonator according to the present invention comprises (a) a piezoelectric substrate and
(B) an Ag electrode provided on the surface of the piezoelectric substrate,
(C) High melting point fine particles provided on the surface of the Ag electrode,
It is characterized by having. And the Ag electrode is Ag
It is preferable to elastically make contact with a metal terminal provided with a film on its surface.

A piezoelectric component according to the present invention comprises (d) the piezoelectric resonator according to claim 1 or 2, and (e)
A metal terminal provided with an Ag film on the surface thereof, the metal terminal being in contact with the surface of the Ag electrode of the piezoelectric resonator and holding the piezoelectric resonator.

[0007]

With the above structure, A provided on the surface of the piezoelectric substrate
Since the g electrode contacts the Ag film of the metal terminal through the high melting point fine particles in the middle, the direct contact area between the Ag electrode and the Ag film is reduced, and the self-fusion of Ag is suppressed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a piezoelectric resonator according to the present invention and a piezoelectric component using the piezoelectric resonator will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, the piezoelectric resonator 1 includes a piezoelectric substrate 2, a vibrating electrode 3 provided on the entire front and back surfaces of the piezoelectric substrate 2, and a high melting point adhered to the surface of the vibrating electrode 3. And fine particles 4 of. The piezoelectric substrate 2 is made of ceramic such as PZT, quartz, or single crystal such as LiTaO ₃ . The vibrating electrode 3 is Ag sputtering,
It is formed by means such as vapor deposition or print drying.

The fine particles 4 having a high melting point are made of a material having a higher melting point than the vibrating electrode 3, such as ceramics such as alumina or glass,
Alternatively, Ni, Cr, W, Ti, Mo, Ni-Cu (monel), etc., and alloys thereof are used. The fine particles 4 having a high melting point are attached to the surface of the vibrating electrode 3 or embedded in the vibrating electrode 3 by spraying the fine particles 4 on the surface of the vibrating electrode 3 by, for example, a sandblast method. Alternatively, the high melting point fine particles 4 are attached to the surface of the vibrating electrode 3 or embedded in the vibrating electrode 3 by stirring the fine particle 4 and the piezoelectric resonator 1 in the same container by a stirring method. . The reason why the fine particles 4 are embedded in the vibrating electrode 3 by the sandblast method or the stirring method is that the vibrating electrode 3 is made of Ag, which is relatively soft among metals. If the fine particles 4 are embedded in the vibrating electrode 3, even if the fine particles 4 are insulative, the electrical connection between the vibrating electrode 3 and a metal terminal described later does not occur, and there is a concern that the fine particles 4 may fall off the vibrating electrode 3. Disappear. The high melting point fine particles 4 are provided on the vibrating electrode 3 at a density that does not impair the characteristics of the vibrating electrode 3.

Further, if necessary, the vibrating electrode 3 to which the fine particles 4 having a high melting point are attached by a sand blast method, a stirring method or the like is washed, mechanically rubbed, or shaken to remove excess. The fine particles 4 are removed, and the fine particles 4 are arranged in the concave portions of the vibrating electrode 3 to smooth the surface of the vibrating electrode 3. The particle shape and the shape of the high melting point fine particles 4 are arbitrary, and are variously changed according to the specifications.

FIG. 3 shows a resonator 9 assembled using the piezoelectric resonator 1 thus obtained. This resonator 9 is KH
It operates in the z band, and the inner case 10 has metal terminals 11,
The piezoelectric resonator 1 and the metal terminal 13 are housed in an overlapping manner, the opening of the inner case 10 is closed with an inner lid 14, further covered with an outer case 15, and sealed with a sealing resin 16. The piezoelectric resonator 1 is sandwiched between the metal terminals 11 and 13 at the front and back central portions thereof and vibrates in a spreading vibration mode. The metal terminals 11 and 13 are obtained by providing an Ag film on the surface of a plate material such as phosphor bronze by means such as plating. Metal terminals 11, 13
Has a spring property and is elastically in contact with the piezoelectric resonator 1 as a contact.

In the resonator 9 having the above structure, the vibrating electrode 3 of the piezoelectric resonator 1 comes into contact with the metal terminals 11 and 13 through the high melting point fine particles 4 in the middle, so that the vibrating electrode 3 and the metal terminal 11 and The direct contact area with 13 is small and the vibrating electrode 3
Of Ag and the metal terminals 11 and 13 are less likely to self-bond, and even if vibration energy generated when the piezoelectric resonator 1 resonates is applied to the contact portion between the vibration electrode 3 and the metal terminals 11 and 13, There is no concern that a part of 3 will be peeled off from the piezoelectric substrate 2.

The piezoelectric resonator according to the present invention and the piezoelectric component using the piezoelectric resonator are not limited to those in the above embodiment, but can be variously modified within the scope of the invention. In particular, the fine particles having a high melting point do not necessarily need to be attached to the entire surface of the Ag electrode of the piezoelectric substrate, and may be locally attached to a portion in contact with the metal terminal.

[0014]

As is apparent from the above description, according to the present invention, since the high melting point fine particles are provided on the surface of the Ag electrode of the piezoelectric resonator, the Ag electrode has the high melting point fine particles interposed therebetween. Since the Ag film comes into contact with the metal terminal provided on the surface, the direct contact area between the Ag electrode and the Ag film is reduced, and
g self-fusing is less likely to occur. As a result, problems such as the peeling of a part of the Ag electrode from the piezoelectric substrate are reduced, and the reliability of electrical connection between the Ag electrode and the metal terminal is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a piezoelectric resonator according to the present invention.

FIG. 2 is a partially enlarged sectional view of a vibrating electrode of the piezoelectric resonator shown in FIG.

FIG. 3 is a sectional view showing a piezoelectric component using the piezoelectric resonator shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric resonator 2 ... Piezoelectric substrate 3 ... Vibration electrode (Ag electrode) 4 ... High melting point fine particles 9 ... Resonator (piezoelectric component) 11, 13 ... Metal terminals

Claims (3)

[Claims] 1. A piezoelectric resonator comprising: a piezoelectric substrate; an Ag electrode provided on the surface of the piezoelectric substrate; and high-melting point fine particles provided on the surface of the Ag electrode. 2. The piezoelectric resonator according to claim 1, wherein the Ag electrode has a portion on its surface that elastically makes contact with a metal terminal provided with an Ag film on its surface. 3. The piezoelectric resonator according to claim 1 or 2, and a metal terminal provided with an Ag film on the surface, which holds the piezoelectric resonator by contacting the Ag electrode surface of the piezoelectric resonator. , And a piezoelectric component.