JPS628609A - Piezoelectric vibrator - Google Patents

Abstract

PURPOSE:To suppress generation of undesired vibration by prolonging couplers from four corners of a vibrator along a couple of opposed sides of the vibrator respectively so as to be crossed with the vibrating direction of the vibration. CONSTITUTION:The four thin and log couplers 26a-26d are prolonged respectively from the four corner of the vibrator 2 along longer sides B of the vibrator 2 so as to be nearly orthogonal in the vibrating direction of the short side spread vibration thereby supporting the four corners of the vibrator 2 to a frame 4. Thus, not only the bending vibration and the long side spread vibration are suppressed but also the symmetrical ram wave which have been impossible of suppression conventionally is suppressed and the characteristic is made stable. Further, the mechanical strength is increased remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a piezoelectric vibrator that utilizes short side or long side wave vibration of a quadrilateral vibrator.

[Conventional technology]

For example, there is a piezoelectric vibrator that utilizes short-side spreading vibration of a quadrilateral vibrator as shown in FIGS. 2 and 3. This piezoelectric vibrator includes a rectangular vibrator 2, a frame 4 surrounding it with a space left, and two elongated connectors 6a and 6b that support the vibrator 2 from the frame 4 on the center line of the short side A. , is integrally formed of a plate-shaped constant elastic metal material such as an iron-nickel alloy, and a piezoelectric thin film 8 of, for example, zinc oxide is formed on one main surface of the vibrator 2 by, for example, sputtering. An electrode film 10 made of silver or the like is formed by, for example, sputtering. In this example, in order to draw out the electrodes, a piezoelectric thin film 8 is also formed on the surface of one connector 6a and the part of the frame 4 adjacent thereto, and a lead wire 12 and a lead electrode 14 are formed thereon. are formed together. Then, the extraction electrode 14 and the frame 4 facing it. For example, a leaf spring-shaped lead terminal 1
6a and 16b are pressed from above and electrically connected. Note that the reference numeral 18 in FIG. 3 is a case.

[Problem that the invention seeks to solve]

Although the piezoelectric vibrator described above has a short-side spreading vibration in the length direction of the short side A as shown by the arrow in FIG. There is a problem in that unnecessary vibrations such as bending vibration, long-side wave vibration in the longitudinal direction of the long side B, and symmetrical Lamb waves in which the four corners of the vibrator 2 are deformed into a shape are generated.

In addition, the characteristics of the piezoelectric vibrator ( For example, the spurious response ratio, response, etc.) are affected, so there is also the problem that it is difficult to obtain stable characteristics.

This kind of problem can be solved when using long side wave vibration,
This is common to quadrilateral oscillators, such as when a square oscillator is used.

Therefore, an object of the present invention is to provide a piezoelectric vibrator that can suppress the occurrence of unnecessary vibrations as described above and can stabilize its characteristics.

[Means for solving problems]

The piezoelectric vibrator of the present invention is characterized in that the couplers are extended from the four corners of the vibrator along a pair of opposing sides of the vibrator to intersect the vibration direction of the vibration in use.

[Effect]

Since the couplers extend from the four corners of the vibrator along the pair of opposing sides, they hardly interfere with the spreading vibration of the vibrator.Moreover, by providing the couplers in this way, unnecessary Vibration is suppressed and the characteristics are also stabilized.

〔Example〕

FIG. 1 is a plan view showing a piezoelectric vibrator according to an embodiment of the present invention. Components equivalent to those in FIGS. 2 and 3 are given the same reference numerals and their explanations will be omitted.

In this piezoelectric vibrator, four elongated connectors 26a
~26d extend from the four corners of the vibrator 2 along the long side B of the vibrator 2, in other words, the vibration direction of the short side wave vibration as shown by the arrow in the figure is applied to the four corners of the vibrator 2. The connectors 26a to 26d are arranged so as to be substantially orthogonal to each other, so that the four corners of the vibrator 2 are supported with respect to the frame 4. In this example, the electrode film 10 and the extraction electrode 14 are connected by two extraction lines 12a and 12b provided on the connectors 26a and 26b. Note that the lead terminals 16a and 16b mentioned above.

Although the case 18 is not shown, such a case may be used in this example as well.

In this piezoelectric vibrator, the coupling elements 26a to 26d extend substantially perpendicularly to the vibration direction of the short-side wavy vibration of the vibrator 2, so that they hardly interfere with the vibration. Moreover, by providing the couplers 26a to 26d as described above, it is possible not only to suppress bending vibration and long-side wave rolling vibration, but also to suppress symmetrical Lamb waves, which was impossible in the past. . This is because the conical expansion of the four corners of the vibrator 2 is suppressed by the connectors 26a to 26d.

In addition, unlike conventional piezoelectric vibrators, the four corners of the vibrator 2 are supported instead of supporting the center line of the vibrator 2, so the symmetry (balance) of the vibrator 2 may be disrupted depending on the machining accuracy. Therefore, characteristics such as spurious ratio and response are stabilized.

Conventionally, when processing the vibrator 2 by, for example, etching, the corners C1 to C of the vibrator 2 (see FIG. 2) are omitted because the left half is the same as the right half.

) is rounded (with a so-called R), and this is especially true for the corner C.
, SC4 being round causes variations in the characteristics such as the resonant frequency of the piezoelectric vibrator, but in this embodiment, the long side B of the vibrator 2 and the side sides of the couplers 26a to 26d are linear. Since there are no angles that correspond to the conventional angles CI- and Ca, this also stabilizes the characteristics.

In addition, in conventional piezoelectric vibrators, there was a risk that the vibrator 2 would be twisted around the center line due to something hitting it during manufacturing, etc., but in this piezoelectric vibrator, the vibrator 2 Since it is supported at the four corners, such twisting can be prevented, and mechanical strength is also greatly improved.

Furthermore, in the case of a structure in which the lead wires are passed on the connector and connected to the outside as described above, the number of lead wires can be doubled compared to the conventional method. Lines 12a and 12b sides can be used,
Doing so will improve credibility. Of course, connector 26
It is possible to provide lead lines and lead electrodes on the c and 26d sides as well.

However, in that case, the lead terminal 16b (Fig. 2, 3)
Since it is necessary to attach the lead terminal 16a (see figure) upside down with respect to the lead terminal 16a, the one shown in Fig. 1 is preferable in terms of manufacturing.

〔Effect of the invention〕

As described above, according to the present invention, unnecessary vibrations are suppressed and characteristics are stabilized. Furthermore, mechanical strength is also significantly improved.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a piezoelectric vibrator according to an embodiment of the present invention. FIG. 2 is a plan view showing a conventional piezoelectric vibrator. FIG. 3 is a cross-sectional view taken along line mm in FIG. 2.

Claims (1)

[Claims] (1) A quadrilateral vibrator, a frame surrounding it, and a connector that supports the vibrator from the frame are integrally formed from a plate-shaped constant elastic metal material, and a piezoelectric thin film is formed on one main surface of the vibrator. In a piezoelectric vibrator further comprising an electrode film formed thereon, the couplers are extended from the four corners of the vibrator along a pair of opposing sides of the vibrator to intersect with the vibration direction of the vibration in use. A piezoelectric vibrator featuring: