JPS6357965B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a non-energy confining piezoelectric resonator.

Conventionally, non-energy confining piezoelectric resonators,
For example, in a piezoelectric ceramic resonator, the resonant element is sandwiched between electrode supports from both sides, and housed in a molded resin case 11 having an opening on one side as shown in FIG.
After covering the two, the two were manufactured by welding or gluing.

When the resonator is housed in a resin case in this manner, it becomes large in size and has a disadvantage in that the shape is not suitable for the purpose of downsizing and mass production of ceramic resonators and the like.

For this reason, it is possible to make the shape smaller and thinner by using a resin dip type (so-called dip exterior method), but in this case, it is difficult to make a cavity only around the vibrating part so as not to interfere with the vibration of the resonant element, and it is not practical. It had become an obstacle.

On the other hand, according to Japanese Patent Publication No. 45-22384, after a film is formed on the resonator electrode part using a material that is solid or semi-solid at room temperature and easily melts when heated, an insulating resin layer is formed by a dipping method or a molding method.
Energy trapping type porcelain, characterized in that a void is provided above the resonator electrode section by heating the coating during or after the formation of the insulating resin layer to melt the coating and absorb it into the insulating resin layer. A method of manufacturing corrugated equipment is described.

However, the content of the above publication is to directly apply a material such as wax to only the resonator electrode portion partially formed on the substrate to form a cavity only around the vibrating electrode portion of the resonator. When the target is a non-energy-containing resonator that utilizes bending vibration, longitudinal vibration, contour vibration, radial vibration, etc. in which the entire piezoelectric resonator vibrates, it is necessary to make the entire area around the resonator hollow. Therefore, it is necessary to uniformly apply wax, etc. to the entire resonator with an appropriate thickness, which leads to problems such as an increase in the amount of wax, etc. applied and a decrease in workability. It was hot.

This invention was made to solve the above-mentioned problems.In order to form a cavity that does not interfere with the vibration of a resonator configured with a resin dip shape, a resonator is created in advance using wax, paraffin, etc. A frame with a shape that can contain the elements is provided,
A resonant element is housed in this frame assembly, and after sandwiching it with terminal-equipped electrode supports from both sides, an exterior resin is applied using a dip method, etc., and this resin is heated and baked.
It is an object of the present invention to provide a method for manufacturing a piezoelectric resonator in which a cavity is formed around the entire resonant part by melting the frame and adsorbing or volatilizing it in the exterior resin by capillary action.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an outline of a method for manufacturing a two-terminal, non-energy confinement type piezoelectric ceramic resonator according to an embodiment of the present invention. In the figure, 1 is a resonant element in which vibrating electrodes are formed on both sides of the piezoelectric ceramic. Yes, this resonant element 1 is built into a frame 2 made of wax or paraffin, and this is connected to 3a,
Preferably, the resonant element 1 is completely sealed by sandwiching it between both sides with a support body with a terminal shown in 3b, and then a resin exterior is applied and integrated.

Preferably, protrusions are provided on the upper and lower surfaces of the four corners of the frame assembly 2, respectively, integrally with the frame assembly 2, while holes or recesses into which the protrusions enter are provided at the four corners of the supports 3a and 3b with terminals for positioning. is the capacity.

Note that contact protrusions 4a, 4b are provided at the center portions of the inner surfaces of the terminal supports 3a, 3b.

In addition, as the exterior resin, a thermosetting insulating resin such as epoxy or phenolic resin dissolved in a solvent is used, and it is sandwiched between the supports 3a and 3b with terminals via the frame 2 by dipping or coating. The resonator body made of the resonator element 1 is then attached to the resonator body.

The resonator according to the present invention manufactured through the above steps has the structure shown in FIG. It is in contact with Wakugumi 2.

Next, as shown in FIG. 3B, when the exterior resin 5 is heated and baked to harden, the frame 2 melts or evaporates, and is absorbed into the interior of the exterior resin 5, which has become porous due to the action of volatilization of the solvent. or volatilized;
A cavity is formed between a resonant element 1 having a vibrating electrode formed on the surface of a piezoelectric ceramic substrate and an exterior resin 5. Since the exterior resin contracts due to baking, an appropriate holding pressure can be applied to the resonant element.

As a result, the resonant element can vibrate suitably.

As described above, according to the method of the present invention, a cavity suitable for the vibration of the piezoelectric resonator can be formed between the resonant element and the exterior resin without directly attaching wax or the like to the resonant element. There is no risk of deterioration of vibration characteristics due to residual marks of wax, etc., and the shape of the resonant element is not limited to the rectangular shape shown in the example, but can also be applied to resonant elements of round shape or other shapes in the applicable frequency band. Therefore, its application range is wide.

Furthermore, the structure is dip-shaped, eliminating the need for a resin case that was previously required, making the resonator smaller and thinner, ensuring reliable sealing, improving reliability, and making it suitable for mass production. As a result, costs can be reduced, and the effects are remarkable.

Note that the term "resonator" as used in this specification refers to all devices that utilize resonance phenomena, such as filters, oscillators, and FM discriminators.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional resin case type resonator, Fig. 2 is an exploded perspective view showing a configuration example of the resonator of the present invention, and Fig. 3 is an embodiment of the present invention, showing aspects of the manufacturing process. FIG. DESCRIPTION OF SYMBOLS 1... Resonance element, 2... Frame assembly, 3... Terminal, 3a, 3b... Support with terminal, 4a, 4b...
...Contact protrusion, 5...Exterior resin.

Claims (1)

[Claims] 1 A resonant element with a resonant electrode formed on a piezoelectric substrate,
It is stored in a frame made of a material that is solid at room temperature but easily melts or evaporates when heated.
After sandwiching with supports with terminals from both sides, the outer surface is covered with an insulating resin, and the frame assembly is melted or volatilized when the coating resin is baked and heated,
A method for manufacturing a non-energy-containing piezoelectric resonator, characterized in that a cavity is provided between the resonant element and the exterior resin.