JP2003318698A - Working method for quartz piece and quartz resonator worked by this method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working method for a quartz piece, capable of working a quartz piece so that its cut surface becomes vertical to, e.g. the main surface and planar, thereby realizing superior resonant characteristics, and to provide resonator. <P>SOLUTION: The quartz pieces 1, 2 are cut and formed by wet etching and blasting process for blasting fine powder, and the quartz resonator is cut and formed by the wet etching and the blasting process for blasting the fine powder. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing a crystal piece which is capable of fine processing and is suitable for mass production, and a crystal resonator processed by this processing method.

[0002]

2. Description of the Related Art Conventionally, in the manufacturing process of a crystal unit, a synthetic quartz crystal is cut into a plate shape using a multi-blade saw, the outer shape is formed into a strip or a round plate, and then the plate surface is polished. The thickness is set to a desired value and the target resonance frequency is set.

However, the shape of the crystal unit tends to be remarkably downsized, and the size of the smallest crystal unit is 1 m.
There is also one that uses a crystal piece with a size of about mx 2 mm,
The productivity is low with conventional mechanical processing. A large number of tuning fork-shaped crystal oscillators are also used, and with such a miniaturized crystal unit, the processing efficiency becomes low in conventional mechanical processing.

For this reason, in some oscillators, a mask having a predetermined shape is formed on the plate surface of the crystal piece, and wet etching is performed, for example, by immersing the crystal piece in a hydrofluoric acid aqueous solution to obtain a plurality of individual pieces from one crystal plate. It is considered that the outer shape is processed so as to obtain In such wet etching, a relatively good processing speed can be obtained by optimizing the conditions. However, the quartz piece has a crystal axis, and the etching rate differs depending on the axial direction.

On the other hand, most of the cut surfaces of the crystal pieces are vertical except for those which are tilted at a certain angle with respect to the main surface for a special purpose. On the other hand, the cut surface of the crystal piece processed by wet etching is inclined from the vertical direction of the main surface,
Alternatively, there is a problem in that good vibration characteristics cannot be obtained because the surface becomes curved and distortion occurs in the shape.

Further, a plurality of quartz plates may be used, for example, in Japanese Patent Laid-Open No.
A method of directly joining is known by means such as disclosed in No. -50544 (crystal oscillator). Then, wet etching the plates bonded by such a method,
For example, it is considered to obtain a large number of tuning fork type vibrators having the shape shown in the perspective view of FIG. 2 at one time.

In such a case, the pair of leg portions 11 of the tuning fork
It is desired that the front end surface 12 of the is rectangular as shown in FIG. However, since the etching rate of quartz differs depending on the direction of the crystal axis, for example, as shown in FIG.
In some cases, the external shape was distorted and the desired performance could not be obtained.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to machine a cut surface in a vertical direction with respect to the main surface and to form a flat surface. An object of the present invention is to provide a method of processing a crystal piece capable of realizing vibration characteristics and a crystal resonator processed by this processing method.

[0009]

According to a first aspect of the present invention, there is provided a method of processing a crystal piece, which is characterized in that the crystal piece is cut and formed by wet etching and blasting for spraying fine powder. Item 2 is the method of processing a crystal piece according to the item 1, wherein a protective film is formed on the surface of a non-processed portion of the crystal piece when performing at least one of wet etching and blasting.

Further, a third aspect of the present invention is a crystal resonator characterized in that a crystal piece is cut and formed by wet etching and blasting for spraying a fine powder. In what is described,
A crystal resonator characterized in that a protective film is formed on a surface of a non-processed portion of a crystal piece and processed when at least one of wet etching and blast processing is performed.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The steps of forming two or more tuning fork type vibrators according to an embodiment of the present invention will be described below by laminating two crystal plates and cutting the plate material into a desired shape. 1
This will be described in detail with reference to the sectional views shown in FIGS.

First, as shown in FIG. 1 (a), two crystal plates 1 and 2 cut at a predetermined angle with respect to a crystal axis are processed by a method as disclosed in, for example, JP-A-7-50544. And stick directly. Then, as shown in FIG. 1B, a resist film 4 is applied to both main surfaces of the bonded plate bodies 3.

Then, a mask (not shown) having a pattern corresponding to the shape of the vibrator obtained from the plate 3 is overlaid on the resist film 4 and exposed to light, and, for example, as shown in FIG. The resist film of the non-exposed portion is removed, and the non-processed portion 6 corresponding to the desired tuning fork shape, that is, the resist film 4 of the exposed portion is solidified. Then, the plate body 3 is immersed in, for example, a hydrofluoric acid aqueous solution to perform wet etching.

When wet etching is performed for a certain period of time,
For example, as shown in FIG. 1D, the processed portion 5 has a portion having a high etching rate and a portion having a slow etching rate depending on the direction of the crystal axis of the crystal piece. Therefore, when the etching reaches the unprocessed portion 6 which is to be left as the tuning fork type vibrator, the etching is finished.

Then, as shown in FIG. 1E, a protective film 7 is formed on the resist film 4 on the main surface of the plate body 3. The protective film 7 prevents the unprocessed part from being damaged by the blasting process.

Then, as shown in FIG. 1 (f), the processed portion 5
A blast process is performed on the crystal parts to scrape off the crystal pieces remaining in the processed part 5. In this case, since the protective film 7 made of, for example, silicone resin is formed, the entire surface of the plate body 3 on which a large number of tuning fork vibrators are formed can be simultaneously blasted, which is suitable for mass production and good. High productivity.

In the blast processing, for example, the particle size is several tens of μm.
Fine powder is sprayed on the workpiece together with high-pressure air to enable fine cutting. Therefore, although the processing speed is slower than that of wet etching, fine processing can be performed on a desired portion.

As described above, by performing the wet etching and the blasting process in combination, a desired processed surface can be obtained, and thereby good vibration characteristics can be realized. When considering processing efficiency, perform etching until just before etching reaches the non-processed part,
Although it is conceivable to remove the remaining processed portion by blasting, it goes without saying that the present invention is not limited to this.

For example, wet etching may be performed on a portion having a low processing speed by wet etching and then wet etching may be performed, and the blast processing may be performed again immediately before the wet etching reaches a non-processed portion. . That is, by combining both wet etching and blasting, a material having etching anisotropy such as quartz can be processed into a desired shape with good processing efficiency.

[0020]

As described in detail above, according to the present invention, it is possible to efficiently process a crystal piece into a desired shape, and to obtain good vibration characteristics by such processing. A processing method and a crystal resonator processed by this processing method can be provided.

[Brief description of drawings]

1A to 1F are cross-sectional views illustrating a processing procedure according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of a tuning fork vibrator.

3 (a) and 3 (b) are plan views comparing the front end faces of the customers of the tuning fork vibrators.

[Explanation of symbols]

1, 2, ... Crystal pieces 3 ... Plate 5 ・ ・ Processed part 6 ・ ・ Non-processed parts 7 ... Protective film

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Uehara             2 days at 1275, Kamihirose, Sayama City, Saitama Prefecture             Inside the Sayama Plant of Honden Kogyo Co., Ltd. F term (reference) 5J108 BB02 CC06 KK01 MM11

Claims (4)

[Claims] 1. A method of processing a crystal piece, which comprises cutting and molding the crystal piece by wet etching and blasting in which fine powder is sprayed. 2. A crystal piece according to claim 1, wherein a protective film is formed on a surface of a non-processed portion of the crystal piece when performing at least one of wet etching and blasting. Processing method. 3. A crystal resonator, which is obtained by cutting and molding a crystal piece by wet etching and blasting in which fine powder is sprayed. 4. The method according to claim 3, wherein a protective film is formed on the surface of the non-processed portion of the crystal piece when the wet etching and / or the blasting are at least performed. Characteristic crystal unit.