JPS5828927B2 - Holding structure of thickness-shear oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a holding structure for a thickness-shear vibrator that can be downsized and has a simple structure.

Thickness-shear resonators, such as AT-cut crystal resonators, form an electrode,
A high frequency voltage is applied there to excite thickness shear vibration.

FIG. 1 is a cross-sectional view showing the vibration state of a general thickness-shear oscillator.

When an electrode film 2 is formed on the piezoelectric vibrator 1 by vacuum deposition or the like and a high frequency voltage is applied thereto, thickness shear vibration is excited.

In an ideal state where thickness shear vibration is not affected by external influences, it shows a displacement distribution as shown by the arrows in the figure.

However, when this type of thickness-shear vibrator is actually used, its shape is subject to various restrictions, and it is extremely difficult to realize the ideal state as described above.

Furthermore, since the size of each element of the vibrator is finite, it is also difficult to eliminate parasitic vibrations that occur in the circumferential portion.

Further, in order to support the vibrator element in a certain way and seal it in a predetermined container, an external force is applied from the holding part to the vibrator element, making the state further far from ideal.

Due to such an influence, the thickness-shear vibrator has a problem of deterioration of its electrical characteristics, resulting in various inconveniences in use.

Conventionally, as a method of reducing the external force applied from the holding part of a thickness-shear vibrator to the vibrator element, conductive rubber was interposed between the electrode of the holder and the vibrator element to maintain and conduct the element. Something was being done.

FIG. 2 is a cross-sectional view showing an example of a conventional holding structure for a thickness shear vibrator, in which a pair of electrodes 5 are provided on a retainer base 4, and an electrode 6 is formed between the electrodes 5. The element piece 7 is placed with a conductive rubber 8 interposed therebetween, and a retainer cover 10 is placed over the thickness shear vibrator via an elastic body 9 such as rubber or a metal spring, and then placed on the retainer base 4. I am trying to attach it and enclose it.

In this case, electrical continuity with the electrode 6 of the piece 7 is achieved through contact between the electrode 6 and the metal particles in the conductive rubber 8.

However, since such conductive rubber 8 maintains conductivity by mixing a large number of metal particles in the insulating rubber,
This impairs the good elasticity of the rubber itself, making it difficult to maintain a stable state for a long period of time, and the contact resistance between metal particles cannot be ignored, causing deterioration of the electrical characteristics of a thickness-shear oscillator. It had become.

Therefore, the present invention improves the electrical characteristics of the vibrator by using a material with a layered structure of insulating rubber and metal foil or metal wire as a holding member that can maintain good elasticity and also has conductivity. To provide a holding structure for a thickness-shear vibrator that reduces the external force exerted on the vibrator element from a holding part among deteriorating influences, and maintains the electrical characteristics of the vibrator stably for a long period of time. The purpose is to

An embodiment of the present invention will be described below with reference to the cutaway side views of the ends of the vibrator elements shown in FIGS. 3a and 3b.

Note that the same parts as in FIG. 2 are given the same reference numerals and their explanations will be omitted.

In the figure, reference numeral 11 denotes a holding member inserted between the electrode 5 of the cage base 4 and the electrode 6 of the thickness-shear vibrator element piece 7.

This holding member 11 is made by laminating an insulating elastic body 11a, such as rubber, and a conductive material 11b, such as metal foil or metal wire, in a multilayered structure.

Note that FIG. 3a shows a case where the electrode 6 formed on the vibrator element piece 7 and the electrode 5 provided on the retainer base 4 are opposed in parallel, and in this case, the insulating rubber 11a and the conductive material 1
It is most effective to arrange 1b in a layered structure with a slight inclination as shown in the figure.

Further, Fig. 3 shows a case where the electrode 6 of the vibrator element piece 7 and the electrode 5 of the retainer base 4 are opposed at right angles, and in this case, the insulating rubber 11a and the conductive material 11b are connected as shown in the figure. It is effective to arrange them in a tilted layered structure.

A single layer of the conductive material 11b can provide sufficient conduction, but by providing multiple layers, reliable conduction can be obtained without impairing the elasticity of the insulating rubber 11a.

If such a holding member 11 is used to hold and conduct the thickness-shear vibrator, the external force applied from the holding part to the vibrator element can be extremely minimized, and the elasticity of the insulating rubber 11a can be kept to a minimum. Therefore, it is possible to improve the quality of the thickness-shear oscillator.

Furthermore, the holding structure of the present invention can be easily miniaturized;
We can supply inexpensive, high-quality thickness-shear resonators.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the vibration mode of a thickness-shear oscillator, Fig. 2 is a sectional view showing an example of a conventional holding structure, Fig. 3a is a cutaway sectional view showing an embodiment of the present invention, and Fig. 3 FIG. 6 is a cutaway sectional view showing another embodiment of the present invention. 4...Case for cage, 5...Electrode,
6... Electrode, 7... Thickness shear vibrator, 11... Holding member, 11a... Elastic material, 11b... Conductive material .

Claims (1)

[Claims] 1. A thickness-shear oscillator is constructed by interposing a holding member made of a multilayer stack of insulating elastic material and conductive material such as metal foil or thin metal wire between the thickness-shear oscillator and the electrode for the output terminal of the case. A holding structure for a thickness-shear vibrator, which is characterized by holding a thickness-shear vibrator.