JPH0818371A - Manufacture of crystal vibrator - Google Patents

Abstract

PURPOSE:To easily form electrodes which are separated in the thickness direction of a thin crystal plate. CONSTITUTION:The electrodes which have the different polarities are formed in the thickness direction on an etched surface so that the depth of etching is <=1/5 as large as the thickness, and then the remaining part of the etching is broken. Consequently, the A excitation electrode 2 and B excitation electrode 3 which have the different polarities are formed in the thickness direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a crystal unit formed by an etching method.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a tuning fork type crystal unit has a tuning fork portion and a base portion on the side surface of the tuning fork portion, that is, on the etching surface of the excitation portion when manufactured by etching, in the thickness direction. It is necessary to form the divided electrodes and connect them to the opposing surfaces as shown in FIG. 5 so as to form excitation electrodes having different polarities and to excite them. When the thickness of the crystal unit was large, an electrode film was formed on the front surface of the side surface, and then an unnecessary portion was mechanically or chemically peeled off to form a necessary electrode.
Further, in addition to the excitation electrodes, it is necessary to form electrodes having different polarities on the side surfaces also in the drawing electrode portion of the base portion.

[0003]

SUMMARY OF THE INVENTION In the prior art methods,
The thickness of the vibrator becomes smaller as the size of the vibrator becomes smaller, and there is a problem that the electrode cannot be formed by the conventional method of mechanically or chemically removing the unnecessary portion of the electrode.

[0004]

In order to solve the problem, the etching depth for forming electrodes having different polarities in the thickness direction is left less than ⅕ of the thickness of the quartz plate, and the electrodes are formed on the etching surface. The problem was solved by breaking away the remaining portion of the etching to form electrodes having different polarities from the A excitation electrode 2 and the B excitation electrode 3 in the thickness direction.

[0005]

EXAMPLE In order to mold the outer shape of a crystal unit from a crystal plate, a resist film that does not melt in an etching solution is formed in a portion that is not etched and etching is performed. FIG. 2 shows a cross-sectional view of the excitation part of the crystal unit. The thickness of the crystal plate is t _2, and the side surface of the excitation part is left with a thickness t _{1 in the} thickness direction. The thickness t _1, as will become until fall out from t ₁ = 4t _2/5 or less, is etched to form an etching groove 4 from both sides. The resist film is removed, a mask for forming electrodes is formed, and a metal film is formed by means such as vapor deposition. FIG. 3 shows a state in which the side electrode is vapor-deposited. Since the electrodes are vapor-deposited on the side surfaces, vapor deposition is performed obliquely.

FIG. 1 shows a perspective view of the embodiment. By removing the unnecessary portion in FIG. 3, the excitation electrode separated into the A excitation electrode 2 and the B excitation electrode 3 in the thickness direction is formed on the etched surface of the vibrating portion of the crystal unit. The excitation electrodes are connected as shown in FIG. When voltages with different polarities are applied to the opposing electrodes, a force that moves in a direction perpendicular to the electric field works. In the present embodiment, the means for forming the electrodes of the excitation part is shown, but when forming electrodes on the side surface not only by the excitation part but also by electrodes of other parts, it should be useful for separating the electrodes of different polarities. You can Furthermore, although an example of a tuning fork type resonator is given, a crystal resonator of another shape is also effective.

[0007]

According to the present invention, even if the crystal unit is made smaller and thinner, the electrodes divided in the thickness direction can be easily formed on the side surface of the excitation part of the thin crystal unit, so that the crystal vibration can be reduced. It has become possible to reduce the size, thickness, and cost of the child. As a result, it becomes unnecessary to separate electrodes, which is performed after the electrodes are formed, as in the conventional case, and it is possible to apply the present invention even to a downsized vibrator.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment having an electrode according to the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of the present invention in a state where etching is performed from both sides and a central portion is left.

FIG. 3 is a cross-sectional view showing an example of a state in which electrodes are vapor-deposited on the etched side surface of FIG.

FIG. 4 is a cross-sectional view showing an embodiment of the connection of the present invention, in which the etching surfaces are opposite polarities facing each other.

FIG. 5 is a front view, a side view, a top view, and an excitation electrode connection diagram showing an outline of an outer shape of an embodiment of the present invention.

[Explanation of symbols]

 1 Quartz crystal 2 A excitation electrode 3 B excitation electrode 4 Etching groove

Claims (2)

[Claims] 1. A method of manufacturing a crystal resonator, wherein electrodes having different polarities are arranged on etching side surfaces of a crystal plate of a crystal resonator whose outer shape is formed by an etching method, in the thickness direction of the crystal plate. An etching step of forming a remaining portion of the etching on the side surface of the quartz plate, a step of forming a side surface electrode on the side surface portion of the quartz plate, and an electrode having a different polarity on the side surface of the quartz plate by folding and removing the remaining portion of the etching. A method of manufacturing a crystal unit, which comprises a step of forming. 2. A method of manufacturing a crystal resonator, wherein the remaining portion of the etching is formed to be ⅕ or less of the thickness of the crystal plate.