JPH0590878A - Vertical width crystal resonator - Google Patents

Abstract

PURPOSE:To obtain a vertical width crystal resonator that is superior in electric field efficiency having less oscillating energy loss, resulting in the reduction of equivalent serial resistance (R1) by installing exciting electrodes on the etching surface which is orthogonal to the width direction of the oscillating section and by making the central section of the width greater than the end section of the width. CONSTITUTION:Two sides 2 and 4 of a vertical width crystal resonator 1 are beveled. That is, letting the central width of the oscillating section 6 be x0 and the width of the end section be x1, the two sides 2 and 4 are beveled so as to satisfy the relation of x0>x1. Further, the vertical width crystal resonator 1 is usually formed by means of a chemical etching method. The central section of this etching surface is formed to be orthogonal to the electric axis of the quartz. Accordingly, exciting electrodes 3 and 5 are installed so as to surround the etching surface of the central section of a resonator 6. These exciting electrodes 3 and 5, in order to connect them to an external connecting terminal, are installed so as to be collected on one side of the resonator 6, or on the opposite surface. Furthermore, y'-axis and z'-axis are the new y-axis and the new light z-axis obtained by rotating the z plate by theta=20 deg.-30 deg. degrees around the x-axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape of a width-longitudinal quartz oscillator and an excitation electrode. In particular, the present invention relates to a width-vertical crystal oscillator most suitable as a reference signal source for pagers, IC cards, mobile radios, etc., which are strongly required to be compact, highly accurate, shock resistant, and inexpensive.

[0002]

2. Description of the Related Art Crystal oscillators with a frequency of 4 MHz or higher are
A thickness-sliding quartz crystal oscillator, whose frequency is roughly determined by the plate thickness, has been used. In particular, AT cut, which has excellent frequency-temperature characteristics, has been widely used. Further, for these vibrators, a method of forming the vibrator by machining has been adopted.

[0003]

However, since the AT-cut quartz crystal oscillator, which has been widely used in the past, is formed by machining, it is difficult to support the oscillator when miniaturized, and the equivalent series due to vibration leakage is generated. The increase in resistance (R ₁ ) and the occurrence of spurious vibrations were large, and there was a limit to miniaturization. In addition, it is vulnerable to shocks, and further, there is a limit to the cost reduction because it mechanically processes each oscillator one by one, and as a crystal oscillator for ultra-compact portable devices, extremely important problems remain. It was For this reason, a new crystal resonator having a frequency of 4 MHz or more, an ultra-small size, a small equivalent series resistance (R ₁ ), a zero temperature coefficient, and an easy etching process has been desired.

[0004]

The present invention solves the conventional problems by the following methods. That is, in a crystal resonator that vibrates in the width-longitudinal vibration mode, the excitation electrode is arranged on the etching surface perpendicular to the width dimension direction of the vibrating portion, and the width center portion dimension is made larger than the width end portion dimension. The problem is solved by making the part beveled or convex.

[0005]

As described above, the present invention is a width-vertical crystal oscillator, in which the excitation electrode is arranged on the vertical surface in the width direction, and the shape of the vibrating portion is beveled or convex so that the equivalent series resistance (R ₁ ) Is small and has a zero temperature coefficient, a microminiaturized, high-frequency width vertical crystal unit can be obtained.

[0006]

EXAMPLES Next, the present invention will be specifically described based on Examples. FIG. 1 shows an outline view of the width-longitudinal quartz crystal resonator shape and its coordinate system. Both side surfaces 2 and 4 of the width-vertical crystal oscillator 1 have a bevel shape. That is, the width x of the central portion of the vibrating portion 6
_0, when the width x ₁ end, beveling have been made to satisfy x _0> x _1. Further, the width-vertical crystal oscillator 1 of the present invention is usually formed by a chemical etching method. Therefore, the side surfaces 2 and 4 are also called etching surfaces.
Of course, it goes without saying that mechanical processing may be used. The central portion of this etched surface is formed so as to be perpendicular to the electric axis x of the crystal.

Therefore, the excitation electrode 3 for exciting the width-longitudinal mode
And 5 (not shown) are provided centering on the etching surface of the central portion of the vibrating portion 6. The excitation electrodes 3 and 5 are provided so as to be concentrated on one surface of the vibrating portion 6 or to be opposed to each other in order to connect to the external connection terminals. Also, y ', z'
The axis is a new axis of the mechanical axis y and the optical axis z after the Z plate is rotated by θ = 20 ° to 30 ° in the x-axis rotation.

FIG. 2 is a schematic view of another embodiment of the width-longitudinal crystal oscillator shape of the present invention and its coordinate system. Width vertical crystal unit 7
Both side surfaces 8 and 9 have a convex shape. That is, the width x ₀ of the central portion of the vibrating section 10, when the width x ₁ end, convex machining so as to satisfy x _0> x ₁ have been made. Further, as described in FIG. 1, the side surfaces 8 and 9 are called etching surfaces. An excitation electrode 11 and an excitation electrode 12 (not shown) are arranged on this etching surface. The excitation electrodes 11 and 12 are concentrated on one surface of the vibrating portion 10 or are connected to an external connection terminal, or
It is provided on the opposite surface. The y ′ and z ′ axes are the same as in FIG. 1 and 2, the excitation electrodes 3, 5, 11, 12
Is disposed on the entire side surface of the vibrating portion, but of course, it may be disposed on a part of the etching surface of the vibrating portions 6 and 10, and is further perpendicular to the thickness direction (z ′ axis direction). Even if some electrodes are arranged on any surface, sufficient electrical characteristics can be obtained. Further, in the width-vertical crystal oscillator of the present invention, since the frequency constant is approximately 270 kHz · cm, the frequency f = 4.0.
To realize a vibrator of MHz or higher, the width x ₀ is approximately x _0.
= 675 μm (ignoring the bevel or convex processing amount). Therefore, a small width vertical crystal unit can be obtained at a frequency of 4 MHz or higher.

[0009]

As described above, the width-longitudinal crystal oscillator of the present invention has the following remarkable effects due to the shape and the devising of its excitation electrode. (1) Since the vibrating portion is processed into a bevel or convex shape and the excitation electrode is provided on the etching surface, a width-vertical crystal oscillator with small energy loss due to vibration and excellent electric field efficiency can be obtained. As a result, the equivalent series resistance (R ₁ ) becomes smaller. (2) Since this oscillator is formed by the etching method, the size can be reduced. At the same time, it has excellent impact resistance. (3) Since the frequency is roughly determined by the width x ₀ and the frequency constant is approximately 270 kHz · cm, the frequency is 4
Particularly, downsizing is possible at MHz or higher. (4) Since a large number of vibrators can be batch-processed on one wafer at a time, the cost can be reduced. (5) Since the vibrator is formed from the KT cut quartz plate,
Excellent frequency temperature characteristics.

[Brief description of drawings]

FIG. 1 is a schematic view and a coordinate system of an embodiment of a width-vertical crystal oscillator shape of the present invention.

FIG. 2 is a schematic view and another coordinate system of another embodiment of the width-longitudinal crystal oscillator shape of the present invention.

[Explanation of reference signs] 1,7 width vertical crystal oscillator 2,4,8,9 side surface 3,5,11,12 excitation electrode 6,10 vibrating part x ₀ width x ₁ end width x electric axis y'coordinate rotation Machine axis after z'axis Optical axis after rotation

Claims (1)

[Claims] 1. A quartz resonator vibrating in a width-longitudinal vibration mode, wherein an excitation electrode is arranged on an etching surface perpendicular to a width dimension direction of a vibrating portion, and a width center portion dimension is made larger than a width end portion dimension. A width-vertical crystal unit characterized by the following.