JPH05226962A - Oscillator - Google Patents

Abstract

PURPOSE:To obtain the small sized oscillator even when it is vibrated at a low frequency by forming a couple of electrodes polarized in the lengthwise direction of a rectangular ceramic substrate and used to apply an electric field in the broadwise direction to at least one face in parallel with the broad-wise direction of the ceramic substrate to the ceramic substrate. CONSTITUTION:A rectangular electric ceramic substrate 1 is polarized in the lengthwise direction and electrodes 2, 3 having a part opposite to each other in the broadwise direction are formed to a face flat in the broadwise direction. Moreover, the electrodes 2, 3 formed on the front and the rear side respectively are conductors formed on a face in parallel with the broadwise direction and formed integrally respectively. With a voltage applied between the electrodes 2, 3, an electric field is generated between end ridges 2a, 3a of the electrodes 2, 3 opposite to each other and the vibration in the broadwise direction due to energy confinement is caused therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy trap type thickness shear oscillator.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional energy trap type thickness shear oscillator is polarized in the longitudinal direction of a ceramic substrate 41 and is partially opposed to each other on the front and back surfaces parallel to the width direction. A pair of electrodes 42, 43
Is formed. This thickness sliding oscillator is applied to electrodes 42, 43 by applying a voltage to electrodes 42, 43.
An electric field is applied in the thickness direction at a portion where 3 overlaps, energy is trapped, and vibration occurs in the thickness direction. In addition,
Here, the thickness direction refers to the length direction of the shortest surface of the three intersecting surfaces in the rectangular parallelepiped substrate, and the width direction refers to the length of the middle surface of the three surfaces. The direction refers to the direction, and the longitudinal direction refers to the length direction of the surface having the longest length (hereinafter the same).

[0003]

The above-mentioned conventional thickness-shear oscillator has a frequency determined only by the thickness of the ceramic substrate, and is usually used at a frequency of 2 to 6 MHZ. At 2 MHZ, the thickness is about 0.6 mm. In order to vibrate this thickness-sliding oscillator at a frequency lower than 2 MHZ, there is a problem that the thickness of the element becomes large and the oscillator including the package becomes large.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an oscillator capable of obtaining a small one even if it vibrates at a frequency lower than 2 MHZ.

[0005]

The oscillator of the present invention comprises a pair of plates for polarizing an electric field in the width direction on at least one surface of the rectangular parallelepiped thickness slide substrate which is polarized in the longitudinal direction and parallel to the width direction. Forming the electrodes of. In this invention, when a voltage is applied between the pair of electrodes, an electric field is generated in the width direction and energy confinement vibration is generated in the width direction.
Therefore, for example, considering the same thickness and width as a conventional oscillator, the width is larger than the thickness of the substrate.
Causes energy trapping oscillations across the width. The oscillator of the present invention can be vibrated at a lower frequency. In other words, a smaller one is obtained when vibrating at the same low frequency.

[0006]

The present invention will be described in more detail with reference to the following examples. 1A and 1B show a ceramic oscillator according to an embodiment of the present invention. FIG. 1A is a plan view thereof, and FIG. 1B is a side view thereof. In FIG. 1, a rectangular parallelepiped piezoelectric ceramic substrate 1 is polarized in the longitudinal direction,
Also, the planes parallel to the width direction (front and back of the paper in FIG.
The electrodes 2 and 3 having portions facing each other in the width direction are formed. The electrodes 2 and 3 on the front and back sides are conductors formed on surfaces parallel to the thickness direction [the upper surface and the lower surface in FIG. 1B),
Each is integrally formed.

In this oscillator, when a voltage is applied between the electrodes 2 and 3, the opposing edges 2a and 3 of the electrodes 2 and 3 are
An electric field is generated between a and in the width direction [up and down direction in FIG. 1 (b)], and vibration in the width direction is generated here due to energy confinement. As an example, length L = 7.8 mm, width w =
A resonator having a resonance frequency of 950 KHZ and Qm = 200 was obtained with a resonator having a thickness of 1.2 mm and a thickness of t = 0.4 mm. The spurious characteristics of the oscillator of this example are shown in FIG.
As is clear from this spurious characteristic, there is a thickness shear vibration of energy trapping in the width direction,
The third and fifth modes are appearing.

Next, a method for manufacturing the oscillator of the above embodiment will be described. First, as shown in FIG. 3A, the piezoelectric ceramic substrate 31 is polarized in the width direction. Next, electrodes are provided above and below in the thickness direction to adjust the frequency. This frequency adjustment is performed by changing the thickness of the electrode material or by applying a solder resist or the like.

Subsequently, as shown in FIG. 3B, the piezoelectric ceramic substrate 31 is cut into strips in the polarization direction, and many piezoelectric ceramic substrates 32 much smaller than the original piezoelectric ceramic substrate 31 are formed. obtain. Therefore, this piezoelectric ceramic substrate 32 is polarized in the longitudinal direction. Next, as shown in FIG. 3C, the conductor layer 33 for electrodes is formed on the surface parallel to the width direction and the surface parallel to the thickness direction of the piezoelectric ceramic substrate 32 [enlarged version of FIG. 3]. To do. Then, the electrodes 34, 3 are formed by etching.
5 is formed to obtain the oscillator 36.

[0010]

According to the present invention, since a pair of electrodes for polarizing an electric field in the longitudinal direction and applying an electric field to at least one surface parallel to the width direction of a rectangular parallelepiped thickness-sliding substrate is formed, a space between the pair of electrodes is formed. By applying a voltage to, vibration can be obtained by trapping energy in the width direction,
Compared with the conventional one, the element can be made smaller by vibrating at a frequency lower than 2 MHZ. Of course, there is also an advantage that the device is easy to handle because it is energy confinement, and only the overlapping portions of the electrodes vibrate and both ends do not vibrate.

[Brief description of drawings]

FIG. 1 is a diagram showing a ceramic oscillator according to an embodiment of the present invention.

FIG. 2 is a diagram showing a spurious characteristic of the ceramic oscillator of the example.

FIG. 3 is a drawing for explaining the manufacturing method for the ceramic oscillator according to the embodiment.

FIG. 4 is a diagram showing a conventional thickness slip oscillator.

[Explanation of symbols]

 1 Ceramic substrate 2 electrode 3 electrode

Claims (1)

[Claims] 1. An oscillator characterized in that a pair of electrodes for applying an electric field in the width direction is formed on at least one surface of a rectangular parallelepiped thickness-sliding substrate that is polarized in the longitudinal direction and is parallel to the width direction.