JPH02224515A - Piezoelectric vibrator and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a piezoelectric vibrator with ease of assembling and low cost by providing a contact piece being an electric contact part with an outer conductor to part of input and output electrodes and bonding the contact piece with the electrode independently through the use of an isotropic elastic conductor material. CONSTITUTION:Contact pieces 13, 14 being electric contact parts with an outer conductor are bonded to electrodes 22, 32 with a conductive adhesives made of an isotropic elastic conductive material showing equal conductivity in all directions and bonded to electrodes 22, 32 with a conductive adhesives and integrated with a piezoelectric vibrator. Moreover, the contact pieces 13, 14 are made independent via a distance d1 and the electrodes 22, 23 are isolated electrically. Then the contact piece 13, 14 are arranged in the midposition being a node of the vibration in the lengthwise direction and the vibration fault is evaded. Thus, the piezoelectric vibrator with ease of assembling and mounting in a case, no position deviation of the contact piece and inexpensive cost is obtained.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention mainly relates to a piezoelectric vibrator using a longitudinal vibration mode and a method for manufacturing the same, and relates to an input electrode and a piezoelectric vibrator provided on one surface of a piezoelectric element. By independently bonding contact pieces made of isotropic elastic conductive material to each of the output electrodes, assembly is easy and the contact pieces that make electrical contact with the external conductor do not become misaligned. Moreover, it is possible to provide an inexpensive piezoelectric vibrator and a manufacturing method thereof.

<Prior Art> Conventional technologies for piezoelectric vibrators using a longitudinal vibration mode include those described in, for example, Japanese Patent Laid-Open No. 58-99017, Japanese Patent Laid-Open No. 58-99022, and the like. FIG. 4 shows a conventional piezoelectric vibrator disclosed in the above-mentioned publication, in which grooves Sl
In addition, grooves 32 and S3 for spurious reduction are provided on both ends in the length direction, leaving an appropriate interval from the end, and perpendicular to the groove 51, and are partitioned by eight grooves Sl to S3. On the surface, electrodes 21 to 23 and electrodes 31 to
33 is deposited and the electrode 4 is deposited on the other side. The electrodes 21 to 23 and the electrodes 31 to 33 are
When one is a manual electrode, the other is an output electrode. The electrode 4 serves as a common electrode that commonly faces the electrodes 21 to 23 and 31 to 33.

The piezoelectric vibrator described above is usually used by being built into a case. The electrodes 21 to 23, 31 to 33, and the common electrode 4, which serve as input/output electrodes, are led out of the case through terminals.

As shown in FIG. 4, the electrodes 21 to 23 and the electrodes 31 to 33 are on the same surface of the piezoelectric element 1 and are close to each other, so when taking out the electrodes with the terminal, there is no electrical It is necessary to have a structure that is independent and does not cause vibration disturbances. Conventionally, as a means for this purpose, anisotropic conductive rubber has been interposed between the input/output electrodes and the terminals, as disclosed in, for example, Japanese Utility Model Application Publication No. 60-158324. An example is shown in FIG. In FIG. 5, 5 is a piezoelectric vibrator;
6 is anisotropic conductive rubber, 7 to 9 are terminals made of thin metal plates, 1
o is a case molded from insulating resin, 11 is a lid, and 12 is an exterior case.

The piezoelectric vibrator 5 has electrodes 21 to 23, and 31 to 33 in case 1.
The terminal 9 is arranged so as to face the bottom side of the terminal 9, and spring pressure is applied by the spring piece 91 of the terminal 9 to the top side where the common electrode 4 is located.

A terminal 71.8 is arranged on the bottom surface of the case 10, and an anisotropic conductive rubber 6 is interposed in a non-adhered state between the terminal 7.8 and the electrode 22.32 of the piezoelectric vibrator 5. be. The anisotropic conductive rubber 6 is arranged at an intermediate portion in the longitudinal direction that becomes a node of vibration, that is, an electrode 22 so as not to interfere with the vibration of the piezoelectric vibrator.
．． 33, so as to be in contact with each other approximately in the middle.

The anisotropic conductive rubber 6 has conductivity in the thickness direction, but not in the plane direction perpendicular to the thickness direction. Therefore,
The electrode 22 and the terminal 7 and the electrode 32 and the terminal 8 are electrically connected to each other due to the conductivity of the anisotropic conductive rubber 6, but the electrode 22 and the electrode 32 share the anisotropic conductive rubber 6. However, they are electrically isolated from each other.

After the lead-out ends of the terminals 7 to 9 are entirely covered by the outer case 12, they are bent into a predetermined shape as shown by the dashed line.

<Problems to be Solved by the Invention> As described above, the conventional piezoelectric vibrator utilizes the anisotropic conductive rubber 6 to form the electrodes 22 and 32 that serve as input and output electrodes when incorporated into the case. was in electrical contact with terminal 7.8. For this reason, it is essential to use the expensive anisotropic conductive rubber 6, which increases the cost of the product.

Furthermore, when assembling the anisotropic conductive rubber 6 into the case 10, the piezoelectric vibrator 5 must be placed on top of the anisotropic conductive rubber 6, which increases the number of assembly steps. There was also the problem that assembly was troublesome. The piezoelectric vibrator 5 has a width of 0. The anisotropic conductive rubber 6 is an even smaller component, so the conventional structure in which the anisotropic conductive rubber 6 and the piezoelectric vibrator 5 have to be handled separately is difficult to assemble. was extremely bothersome.

Moreover, since the piezoelectric vibrator 5 is placed on the anisotropic conductive rubber 6 in a non-adhered state and is pressed down by the spring pressure of the spring piece 91 of the terminal 9, the anisotropic conductive rubber 6 may be misaligned. There was also a risk that spurious signals would occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a piezoelectric vibrator that solves the above-mentioned conventional problems, is easy to assemble, does not cause displacement of the contact piece that contacts the outside, and is inexpensive. An object of the present invention is to provide a manufacturing method.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention provides a piezoelectric vibrator having an input electrode and an output electrode on one side of a piezoelectric element body, each of the input electrode and the output electrode , a part thereof has a contact piece that becomes an electrical contact part with the external conductor, and each of the contact pieces is made of an isotropic elastic conductive material that exhibits substantially equal conductivity in all directions, and It is characterized in that it is independently connected to each of the input electrode and the output electrode.

The manufacturing method according to the present invention for obtaining the piezoelectric vibrator described above includes forming a conductive film for an electrode on one surface of a piezoelectric substrate, and then cutting the piezoelectric substrate to obtain a single piezoelectric vibrator. After forming the conductive film and before cutting the piezoelectric substrate, an isotropic elastic conductive material exhibiting substantially equal conductivity in all directions is placed on the surface of the conductive film at intervals. The piezoelectric substrate is cut so that independent isotropic elastic conductive pieces remain on each of the input electrode and the output electrode of each piezoelectric vibrator.

Each of the contact pieces that make electrical contact with the external conductor is
Since it is made of an isotropic elastic conductive material that exhibits substantially equal conductivity in all directions, compared to conventional anisotropic conductive rubber,
The cost becomes significantly lower.

In addition, since each contact piece is joined to each of the input electrode and the output electrode, the contact piece is integrated with the piezoelectric vibrator, making it easy to incorporate it into the case, and eliminating the possibility of misalignment. It is possible to avoid the occurrence of spurious signals due to positional deviation.

Since each of the contact pieces is independent from each other, the input and output electrodes are electrically separated, and when installed in the case,
By bringing a terminal, which is an external conductor, into contact with the contact piece, the input/output electrode can be led out to the outside of the case.

In order to obtain the piezoelectric vibrator described above, the manufacturing method according to the present invention includes forming a conductive film for electrodes on a piezoelectric substrate, and then, before cutting the piezoelectric substrate, substantially forming a film on the surface of the conductive film in all directions. Isotropic elastic conductive materials that exhibit equal conductivity are applied in strips at intervals, and then independent isotropic elastic conductive materials are applied to the input and output electrodes of each piezoelectric vibrator. Since the piezoelectric substrate is cut so that pieces remain, the piezoelectric component according to the present invention can be manufactured efficiently.

<Example> FIG. 1 is a perspective view of a piezoelectric vibrator according to the present invention. In the figure, the same reference numerals as in FIG. 4 indicate the same components. 13 and 14 are contact pieces that serve as electrical contact portions with the external conductor. Each of the contact pieces 13.14 is
It is constructed from an isotropic elastic conductive material that exhibits substantially equal conductivity in all directions. The isotropic elastic conductive material is generally a conductive rubber, which is significantly cheaper than conventional anisotropic conductive rubber.

Each of the contact pieces 13.14 has an electrode 22 and an electrode 32.
are joined to each. As a joining means, it is possible to use the adhesive force of the isotropic elastic conductive material itself, or to use a conductive adhesive. As a result, the contact pieces 13 and 14 and the piezoelectric vibrator are integrated, and the case 10
It is easy to incorporate the device into the interior, and no misalignment occurs.

Further, each of the contact pieces 13, 14 is independent from each other with a distance d1 between them, and the electrodes 22-32 are electrically isolated from each other. The distance d1 is between the electrodes 21 to 23 and the electrode 31.
It is almost equal to the groove S1 provided between .

In the case of the illustrated piezoelectric vibrator using the longitudinal vibration mode, the contact pieces 13, 14 have a length of 10,1 from the middle part in the longitudinal direction, which is the node of vibration, that is, from both ends.

Place it at a position where the values are approximately equal. By doing so, vibration disturbances caused by the contact pieces 13, 14 can be avoided.

FIG. 2 is a partial sectional view of a piezoelectric vibrating component in which a piezoelectric vibrator according to the present invention is incorporated into a case. In the figure, the same reference numerals as in FIG. 4 indicate the same components.

The piezoelectric vibrator 5 has electrodes 22, 32, as shown in FIG.
Since it has a structure in which the contact pieces 13 and 14 are integrally joined on top of the piezoelectric vibrator 5, the contact piece 1
3.14 is also incorporated at the same time, making it easy to integrate into the case. Moreover, since no positional deviation occurs in the contact pieces 13, 14, it is possible to avoid spurious generation due to positional deviation.

Since the contact pieces 13.14 are independent from each other with a distance dl between them, and the electrodes 22-32 are electrically isolated, the terminal 7.8, which is an external conductor, is brought into contact with the contact piece 13.14. , the electrodes 22.32 can be led out of the case 10.

FIGS. 3(a) and 3(b) are diagrams showing a method for manufacturing a piezoelectric vibrator according to the present invention. First, as shown in FIG. 3(a), after forming electrode conductive films B and C on a piezoelectric substrate A,
Before cutting the piezoelectric substrate A, isotropic elastic conductive materials D1 to D, which exhibit substantially equal conductivity in all directions, are deposited in strips at intervals on the surface of the conductive film B. . The isotropic elastic conductive materials D1 to Ds are prepared by mixing a conductive component, an organic elastic material such as rubber, and an appropriate solvent to form a paste, and applying it in a predetermined pattern. It can be formed by As a coating means, screen printing or the like can be used.

Next, after going through the steps of drying and curing the isotropic elastic conductive material -D, as shown in Figure 3(b), the required grooves S1 to S3 are cut using a dicing saw or the like. At the same time, the dividing lines (X+ X+) to (X4-X4), (y+
-Yl) to (Y5-Ys). As a result, the piezoelectric vibrator shown in FIG. 1 is obtained.

According to this manufacturing method, it is possible to efficiently mass-produce a piezoelectric vibrator in which a microscopic contact piece is integrally bonded to a piezoelectric element body that is a microscopic component.

<Effects of the Invention> As described above, the piezoelectric vibrator according to the present invention is a piezoelectric vibrator having an input electrode and an output electrode on one side of a piezoelectric element body, and each of the input electrode and the output electrode has the following characteristics: Part of it has a contact piece that becomes an electrical contact with the external conductor,
Each of the nine contact pieces is made of an isotropic elastic conductive material that exhibits substantially equal conductivity in all directions, and is independently joined to each of the input and output electrodes. It is possible to provide a piezoelectric vibrator that is easy to assemble, does not cause displacement of a contact piece that electrically contacts an external conductor, and is inexpensive.

Further, according to the manufacturing method according to the present invention, the piezoelectric vibrator described above can be efficiently mass-produced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a piezoelectric vibrator according to the present invention, FIG. 2 is a partial sectional view of a main part of a piezoelectric component incorporating a piezoelectric vibrator according to the present invention, and FIGS. 3(a) and (b) are FIG. 4 is a perspective view of a conventional piezoelectric vibrator, and FIG. 5 is a partial sectional view of a piezoelectric component incorporating a conventional piezoelectric vibrator. 1... Piezoelectric element bodies 21-23... Input electrodes or output electrodes 31-33.
...Output electrode or manual electrode 4...Common electrode 13.14...Contact piece 51%52, S3...Groove diagram diagram diagram diagram diagram

Claims (3)

[Claims] (1) A piezoelectric vibrator having an input electrode and an output electrode on one side of a piezoelectric element, each of the input electrode and output electrode having a contact piece that serves as an electrical contact portion with an external conductor. each of the contact pieces is made of an isotropic elastic conductive material that exhibits substantially equal conductivity in all directions, and is independently joined to each of the input and output electrodes. A piezoelectric vibrator characterized by: (2) A piezoelectric vibrator using a longitudinal vibration mode, wherein the input electrode and the output electrode are separated by a groove linearly provided on the one surface of the piezoelectric element, and the contact A piezoelectric vibrator characterized in that the pieces are arranged near nodes in longitudinal vibration. (3) After forming a conductive film for an electrode on one surface of the piezoelectric substrate,
A method for manufacturing a piezoelectric vibrator in which a single piezoelectric vibrator is obtained by cutting the piezoelectric substrate, the method comprising: after forming the conductive film, and before cutting the piezoelectric substrate, a film is formed on the surface of the conductive film in all directions. Isotropic elastic conductive material exhibiting substantially equal conductivity is applied in strips at intervals, and independent isotropic elastic conductive pieces are attached to each of the input electrode and output electrode of each piezoelectric vibrator. A method of manufacturing a piezoelectric vibrator, characterized in that the piezoelectric substrate is cut so that a portion of the piezoelectric substrate remains.