JPS589601B2 - Manufacturing method of piezoelectric ceramic vibrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a piezoelectric ceramic vibrator using all types of vibration such as thickness vibration, radial vibration, spread vibration, and bending vibration, and particularly relates to a method for manufacturing a piezoelectric ceramic vibrator in an efficient and economical manner. The present invention relates to a method for manufacturing a piezoelectric ceramic vibrator that is small in size and has no fluctuation in characteristics.

Generally, for piezoelectric ceramic vibrators, it is essential to provide a space near the vibrating part so as not to impede the vibration.
Forming this space is difficult in terms of manufacturing.

Conventionally, as a manufacturing method that facilitates the formation of this space, for example, as described in Japanese Patent Publication No. 45-122384, an electrode part provided on a piezoelectric ceramic plate is coated with a material such as wax. It has been proposed to form a space above the electrode portion by forming an insulating resin layer, and heating the resin layer during or after the formation to melt the film and absorb it into the insulating resin layer. ing.

However, in the piezoelectric ceramic vibrator manufactured by this manufacturing method, a space is formed only above the electrode part, and the peripheral part of the piezoelectric ceramic plate is fixedly supported by an insulating resin layer, making it difficult to store energy. It can only be used for piezoelectric ceramic vibrators, and cannot be used for non-energy confined type vibration modes such as thickness vibration, radial vibration, spread vibration, and bending vibration, which are the object of the present invention.

The present invention improves the conventional manufacturing method of energy-containing type piezoelectric ceramic vibrators, and provides a method that can be used for piezoelectric ceramic vibrators in all vibration modes, and is efficient, economical, and suitable for mass production. The main purpose of this invention is to provide a method for manufacturing a piezoelectric ceramic vibrator that is small and has excellent characteristics.

That is, in the present invention, when supporting a piezoelectric ceramic substrate provided with electrodes, that is, a vibrating element, with a terminal, the annular heat-shrinkable film is shrunk to ensure support and prevent support shift in subsequent steps. That is.

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

In FIG. 1, reference numeral 1 denotes a piezoelectric ceramic vibrating element, with electrodes 1b on both sides of a piezoelectric ceramic substrate 1a made of lead zirconate titanate, etc.
1c is formed.

2 and 3 are terminals, and as extracted and shown in FIG.

) has a larger external shape, and has protrusions 2a and 3a near the center.
Notches 2b and 3b are provided on each side, and drawer portions 2c and 3c extend from one corner.

The protrusions 2 of the terminals 2 and 3 are then shrunk by the contraction of the heat-shrinkable film T suspended around the terminals 2 and 3 so as to surround the vibrating element 1.
The vibrating element 1 is connected to the vibrating element 1 by the terminals 2 and 3 so that a and 3 a are kept in contact with the node point of the vibrating element 1 or its vicinity.
is crimped and clamped.

Reference numeral 4 denotes a porous thermosetting insulating resin layer that covers the entire vibrating element 1 with a space 5 in between, and also covers part of the terminals 2 and 3 (
In the embodiment, not only the lower part of the terminal but also the peripheral part of the terminal is fixed.

However, even though it is called the peripheral part, a part of the notches 2b and 3b is excluded, and in short, the insulating resin layer 4 is connected to the vibration element 1.
It is preferable to provide a space around the entire vibrating element 1 so as not to suppress the vibration of the vibrating element 1.

This insulating resin layer 4 is impregnated with a space-forming material such as wax, paraffin, and vaseline, as will be described in detail later.

The shape of the terminals 2 and 3 is not limited to the above embodiment, but is a shape that contacts the node point of the vibrating element 1 or its vicinity, a shape that makes it easy to hang the heat-shrinkable film T, and a shape that is sufficient to cover the entire circumference of the vibrating element. Any other shape may be used as long as it can be coated with a suitable space-forming material.

Next, various methods of manufacturing the piezoelectric ceramic vibrator described above will be explained.

(1) In FIG. 2, a vibrating element 1 is sandwiched between terminals 2 and 3 that are integrally connected at the bottom.

At this time, the protrusions 2a and 3a of the terminals 2 and 3 are aligned with the node point of the vibrating element 1 or a fixed point in the vicinity thereof.

A heat-shrinkable film T is suspended around the terminals 2 and 3 so as to surround the vibrating element 1.

The heat-shrinkable film T contracts when heat is applied,
This helps the terminals 2 and 3 to clamp the vibrating element 1.

In this way, the vibrating element 1 is fixed with the terminals 2 and 3.

This vibrating element 1 may be made of a molten liquid (a molten liquid may be used) made of a space forming material such as wax, vaseline, or paraffin.

Hereinafter, it will be referred to as molten liquid. ).

In this way, the above-mentioned space forming material is adhered to the terminals 2 and 3 and the outer surfaces of the terminals 2 and 3 except for their peripheral parts, and the first layer 1
Set 0.

This first layer 10 reliably covers the entire periphery of the vibrating element 1 since the vibrating element 1 is located between the terminals 2 and 3 and is made smaller than the outer diameter of the terminals 2 and 3.

Next, the vibration element 1 provided with the first layer 10 is immersed in a liquid made of porous thermosetting insulating resin such as phenol or epoxy, and the second layer 11 is formed on the outside of the first layer 10. establish.

After drying, this second layer 11 is heated, and the heat-shrinkable film T is also completely shrunk, if it has not completely shrunk, so that the terminals 2 and 3 can sufficiently crimp and clamp the vibrating element 1. At the same time, the wax or other material of the first layer 10 is liquefied or vaporized and absorbed into or released from the porous second layer 11 to form a space 12 in the first layer 10.

At this time, notches 2 are provided in the terminals 2 and 3 so that materials such as wax are easily absorbed into the second layer or released to the outside.
b, 3b are provided.

Therefore, the space 12 can be formed around the entire vibrating element 1, and the peripheral edges of the terminals 2 and 3 can be fixed with the second layer 11, so that the vibration is not suppressed in any way, no matter what the vibration state is. From this, a desired piezoelectric ceramic vibrator can be obtained.

(2) Figure 3 shows the second manufacturing method, 20 is a container,
It has a substrate 21 with a large number of holes 21a therein, and a tube 22 at the bottom of which feeds air into the container 20.
is provided.

A powder 23 of wax, paraffin, vaseline, etc. is placed on a substrate 21 within this container 20.

Then, air is sent through the tube 22 to spread the powder 23.

Then, in the same manner as the first method shown in FIG.
, 3 is heated by a heater 24, and then placed in the diffusion powder 23.

Then, the powder 23 is melted and adhered to the entire vibrating element 1, thereby providing a first layer.

The process of providing the second layer and the process of forming the space are the same as those in the first method, so their explanation will be omitted.

(See Figure 2) (3) Figure 4 shows the third manufacturing method,
A container 30 is provided with a conduit 31 having a spray nozzle 31a.

A space-forming material 32 such as wax, paraffin, petrolatum, etc. is placed in this container 30.

An air nozzle 33 is arranged near the spray port 31a, and air is blown from the air nozzle 33 to the spray port 31a to spray the material 32 in the form of a mist.

Then, the vibrating element 1 provided with the terminals 2 and 3 is placed in the atomized material 32, and the material 32 is adhered to the entire vibrating element 1 to form a first layer.

The process of providing the second layer and the process of forming the space are the same as those in the first method, so their explanation will be omitted.

(See Figure 2) By the way, it is common to use soldering to fix the terminal and the vibrating element, but when soldering, the solder spreads over the electrode to an area where it is not necessary, and the terminal The vibration element and the vibration element may not make point contact.

Therefore, soldering requires skill, and the resonant resistance of the vibrator becomes high, resulting in increased loss.

In addition, the heat of the soldering iron may cause the so-called electrode to be eaten away.

Furthermore, with soldering, the electrodes and terminals are bonded more strongly than necessary, so if the bond between the piezoelectric ceramic substrate and the electrode is weak, the electrode may be peeled off from the surface of the piezoelectric ceramic substrate due to impact. be.

However, in the present invention, since the terminal is crimped to the vibrating element by shrinking the heat-shrinkable film, the tip of the protrusion of the terminal can be made sufficiently thin, so that the terminal and the vibrating element come into ideal contact.

Therefore, mechanical damping of the vibrating element by the terminals is reduced, and loss of the vibrating element is reduced.

In addition, costs can be reduced by eliminating the need for skilled processes such as soldering.

Furthermore, since the terminals and the electrodes of the vibrating element are not soldered, the electrodes will not come off due to impact.

The present invention is as described above, and can be used for any type of vibration configuration, and is extremely effective for efficient and economical mass production.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIGS. 2 to 4 are diagrams showing a method for manufacturing a piezoelectric ceramic vibrating element according to the present invention. 1 is a piezoelectric ceramic vibrating element, 2 and 3 are terminals, 4 is a porous thermosetting insulating resin layer, and 5 is a space.

Claims (1)

[Claims] 1. In a method for manufacturing a piezoelectric ceramic vibrator having a piezoelectric ceramic vibrating element and a terminal whose part comes into contact with a node point of the piezoelectric ceramic vibrating element or a fixed point in the vicinity thereof, a terminal having a larger outer diameter than the piezoelectric ceramic vibrating element , a heat-shrinkable film is suspended around the terminal to surround the piezoelectric ceramic vibrating element,
The heat-shrinkable film is shrunk by heat so that the terminal holds the piezoelectric vibrator, and then a space-forming material such as wax, paraffin, or petrolatum is applied to the entire piezoelectric vibrator, and a part of the terminal is A porous thermosetting insulating resin is attached to the entire piezoelectric vibrating element, and the space-forming material is liquefied or vaporized by heat, absorbed by the porous thermosetting insulating resin, or released to the outside, so that the entire piezoelectric ceramic vibrating element becomes a space. 1. A method for manufacturing a piezoelectric ceramic vibrator, characterized in that the piezoelectric ceramic vibrator is coated with an insulating resin cured through a process.