JPH0491510A - Piezoelectric resonator - Google Patents

Abstract

PURPOSE:To prevent the vibration of a vibratory element from being damped and occurrence of short circuit by winding and fixing ring-like members around and to both end sections of the vibratory element. CONSTITUTION:After electrodes 13 and 13 are provided on both surfaces of a piezo-electric substrate 12 in such a state where the electrodes 13 and 13 are faced to each other at the central part of the substrate 12, ring-like members 14 and 14 are wound around and fixed to both end sections of the substrate 12. The members 14 are formed of a heat-shrinkable tube having a heat resisting property and fixed to a vibratory element 11 in such a way that, after the tube is loosely fit around the substrate l near both ends of the element 11, the tube is contracted by heating. The distance A from each end section of the element 11 to each member 14 is arbitrarily selected so that the members 14 do not interfere with the resonant section of the element 11. Therefore, the reliability and yield of this piezo-resonator can be improved and the cost of the resonator can be reduced, because a bonding agent flowing on the surface of the vibratory element can be blocked by means of the ring-like members 14 at the time of assemblage and, accordingly, deterioration of the characteristics of the resonator caused by the damping of the vibrations and short circuit can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a two-terminal piezoelectric resonator in which a thickness-shear vibrating element is housed in an exterior body.

<Prior Art> FIGS. 5 and 6 show a conventional piezoelectric resonator, in which a vibrating element 3 with counter electrodes 2.2 provided on both sides of a piezoelectric substrate 1 is housed in a cylindrical exterior body 4. Then, external electrodes 5.5 made of metal caps are fitted to both ends of the exterior body 4.

Further, the conductive adhesive 6.6 is filled in the outer electrode 5.5, which is usually made of a metal cap, and is fitted into the outer case 4.

(Problems to be Solved by the Invention) By the way, during the piezoelectric resonator assembly process as described above, since the conductive adhesive 6 has fluidity until it is thermoset, the vibrating element 3 may be damaged by its own weight inside the exterior body 4. descend or slope downwards.

When the vibrating element 3 is tilted, there is a problem in that the conductive adhesive 6 flows along the surface of the vibrating element 3 and adheres to the resonant portion, causing vibration damping.

In addition, if the exterior body 4 is a rectangular tube or a cylinder, as shown in FIG.
When the vibrating element 3 descends within the exterior body 4, the lower surface of the vibrating element 3 comes into contact with the inner lower surface of the exterior body 4, a capillary phenomenon occurs between the two contact surfaces, and the conductive adhesive 6 flows into the resonant part.
There are problems in that vibration damping and short circuits occur frequently.

Therefore, in order to solve the above-mentioned problems, this invention aims to provide a piezoelectric resonator that does not cause conductive adhesive to flow into the surface of the vibrating element and can prevent vibration damping and short circuits. There is.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention involves winding and fixing a heat-resistant ring-shaped member around both ends of a vibrating element, and using this ring-shaped member to bind a conductive adhesive. This structure employs a structure that prevents the flow from flowing into the resonant portion of the vibrating element.

<Function> The ring-shaped member wound and fixed at both ends of the vibrating element can prevent the conductive adhesive from flowing into the resonant part, thereby preventing vibration damping and short-circuiting.

<Embodiments> Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 4 of the accompanying drawings.

1 and 2 show a thickness-shear vibrating element 11, in which electrodes 13 are placed on both sides of a piezoelectric substrate 12 made of ceramic.
．． 13 are provided so as to face each other at the center, and ring-shaped members 14 and 14 are wound and fixed at both ends thereof.

The ring-shaped member 14 is formed using a heat-resistant heat-shrinkable tube, and as shown in FIG. As shown in Figure 2 (fixed to the vibration element 11).

By the way, the ring-shaped member 14 has a thickness and width of about 0.5 m.
A distance A from the end of the vibrating element 11 is used.
may be arbitrarily selected within a range that does not affect the resonance part of the vibration element 11.

In FIG. 3, an extraction electrode is formed from the supporting portion of the case body 16 to the upper part of the case.

The vibrating element 11 and the extraction electrode 18, the cover plate 17 and the case body 16, and the case 15 and the external electrode 19 are fixed with a conductive adhesive 2o, so that the electrode 13 of the vibrating element 11 and the external electrode 19 are electrically connected. .

FIG. 4 shows a piezoelectric resonator using a cylindrical body 21 as an exterior body,
The vibration element 11 is housed inside the cylinder 21, external electrodes 19, 19 fitted on both ends of the cylinder 21, and the vibration element 11 is filled with a thermosetting conductive adhesive applied to both ends of the cylinder 21. Immobilized at 2o, electrode 13.13 and external electrode 19.19
It has a structure that connects.

Incidentally, the cylinder '21 used for the exterior body may be a square cylinder or a cylinder (
The vertical cross-sectional structure is approximately the same as that shown in FIG.

The piezoelectric resonator of the present invention has the above-mentioned configuration, and the first
As shown in the figure and FIG. 2, a ring-shaped member 14 is loosely fitted to both ends of the vibrating element 11, and the ring-shaped member 14 is heated and contracted to be wound and fixed.
This vibrating element 11 is housed in a case I5 in FIG. 3 or a cylindrical body 21 in FIG. The agent 2o is heated and cured to form a piezoelectric resonator.

Since the vibrating element 11 has ring-shaped members I4 wound around both ends thereof, the vibrating element 11 is housed in the case 15 or the cylindrical body 21 before the conductive adhesive 2o is cured. Even if the conductive adhesive 2o tries to flow toward the resonant part along the surface of the vibrating element 11 due to the inclination, it is blocked by the ring-shaped member 14, so that the conductive adhesive 20 adheres to the resonant part. Never happened.

Furthermore, when the resonant element 11 is housed in the cylinder 21 as shown in FIG. This ensures that the conductive adhesive 20 does not flow in due to capillary action.

As described above, according to the present invention, heat-resistant ring-shaped members are wound and fixed near both ends of the vibrating element housed in the exterior body, so that the vibrating element can be attached to the exterior body with conductive adhesive. During the assembly process of immobilizing the electrode and connecting it to an external electrode,
The flow of adhesive along the surface of the vibrating element can be blocked by the ring-shaped member, which eliminates vibration damping due to adhesive adhesion to the resonant part and characteristic deterioration due to short circuits, improving product reliability and yield. By doing so, it is possible to reduce costs.

In addition, since the ring-shaped member has heat resistance, it will not be damaged during the heat curing process of the conductive adhesive, and the ability to prevent the flow of the adhesive can be maintained. In this case, a ring-shaped member can be used to secure a gap between the lower surface of the vibrating element and the inner lower surface of the cylinder.
Therefore, it is possible to prevent the adhesive from flowing due to capillary action (and to prevent the adhesive from adhering to the resonant portion).

[Brief explanation of drawings]

1 and 2 are perspective views of a vibrating element used in a piezoelectric resonator according to the present invention, FIG. 3 is a longitudinal cross-sectional view of a piezoelectric resonator using a case as an exterior body, and FIG. FIG. 5 is a vertical cross-sectional view of a conventional piezoelectric resonator, and FIG. 6 is a perspective view showing the external appearance of the same. 11... Vibration element 12... Piezoelectric substrate 3...
- Counter electrode 5... Case O... Conductive adhesive 14... Ring-shaped member 19... External electrode 21... Cylindrical body

Claims (1)

[Claims] A vibrating element with opposing electrodes on both sides of a piezoelectric substrate is housed in an exterior body, external electrodes are fitted on both sides of the exterior body, and the external electrodes and the opposing electrodes of the vibrating element are electrically connected using a conductive adhesive. In this piezoelectric resonator, a heat-resistant ring-shaped member is wound and fixed at both ends of the vibrating element, and this ring-shaped member prevents conductive adhesive from flowing into the resonant part of the vibrating element. Features a piezoelectric resonator.