JPH0865077A - Vibrator and manufacture thereof - Google Patents

Abstract

PURPOSE: To prevent the characteristic degradation of a vibration part by making the tip side of a tongue piece shaped vibration part a plus X direction and etching the outer peripheral part of this tongue piece shaped vibration part with an etchant. CONSTITUTION: In a diaphragm 1, a U-character shaped notch groove 6 is formed by a sand blast and a tongue piece shaped vibration part 7 is formed by this notch groove. In this vibration part 7, the tip side is made a plus X direction, the root side is made a minus X direction and the axial direction is made a Z direction. By etching the outer peripheral part of the vibration part 7 in the notch groove 6 part, a worked alteration layer is eliminated. On the front and rear surfaces of this vibration part 7, an electrode 8 for exitation is formed. The lead electrode 11 is drawn via the root part 10 of each vibration part 7. The terminal part of this lead electrode passes through the diaphragm 1 by a through hole 13, subsequently passes the side of the vibration part 7, is extended to the side opposite to the root part 10 and forms a connection part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrator such as a crystal and a method for manufacturing the vibrator.

[0002]

2. Description of the Related Art A conventional vibrator of this type includes a diaphragm and first and second covers that cover the front and back surfaces of the diaphragm and sandwich the outer peripheral portion of the diaphragm with its outer peripheral portion. Prepare,
The vibrating plate has a tongue-shaped vibrating portion inside the holding portion between the first and second covers, and excitation electrodes are formed on the front and back surfaces of the vibrating portion.

Conventionally, the front and back excitation electrodes of the vibrating section and the first and the first
The connection with the external electrode outside the second cover is made via the lead electrode provided on the inner surface of the first or second cover.

[0004]

A problem with the above-mentioned conventional example is that a tongue-shaped vibrating portion is formed, which is formed by cutting out the outer periphery into a groove shape by, for example, sandblasting. A work-affected layer is formed on the outer circumference of the part,
It was that the characteristics of the oscillator deteriorated.

Therefore, the present invention is intended to prevent deterioration as a vibrator.

[0006]

In order to achieve this object, according to the present invention, the tongue-shaped vibrating portion has its tip end side in the plus X direction and the outer periphery of the tongue-shaped vibrating portion. It was etched with an etching solution.

[0007]

With the above construction, the work-affected layer on the outer periphery of the tongue-shaped vibrating portion is effectively removed by the etching solution, so that the characteristic deterioration of the vibrating portion does not occur.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is a vibrating plate having a plate thickness of 100 μm.
It is composed of a crystal plate. On the front and back of the diaphragm 1,
The covers 2 and 3 made of a crystal plate having a plate thickness of 400 μm are directly joined. It is to be noted that reference numerals 4 and 5 in FIG. 1 are external electrodes and are arranged on a diagonal portion of the back surface of the cover 3. As shown in FIGS. 2 and 3, the vibrating plate 1 has a U-shaped cut groove 6 formed therein by sandblasting, thereby forming a tongue-shaped vibrating portion 7. The vibrating portion 7 has a tip end side in the positive X direction and a base side in the negative X direction.
The direction and the width direction are the Z direction. Excitation electrodes 8 and 9 are formed on the front and back surfaces of the vibrating portion 7, and lead electrodes 11 and 12 thereof are drawn out via a root portion 10 of the vibrating portion 7, respectively. As shown in FIGS. 2 to 5, the end portion of the inner lead electrode 11 forms the through hole 13 in the diaphragm 1.
And then extends to the opposite side of the root portion 10 to form the connection portion 14 through the side of the vibrating portion 7 as shown in FIG. Further, the lead portion 12 forms a connecting portion 15 on the side of the root portion 10. Then, the through hole 1 formed in the cover 3 corresponding to these connecting portions 14 and 15
The conductors 18 in 6 and 17 are connected to the external electrodes 4 and 5, respectively. The outer peripheral portions of the covers 2 and 3 sandwich the front and rear outer peripheral portions of the diaphragm 1 and are directly joined together. However, the covers 2 and 3 are joined together at the outer peripheral portion of the kerf 6 of the diaphragm 1. The portion where the lead electrode 11 passes through the side of the vibrating portion 7 is joined to the cover 3 on the outside thereof. Then, in order to form the lead electrode 11 on the rear surface side of the diaphragm 1 on the side of the vibrating portion 7 as described above, as is apparent from FIGS. The plate thickness is made thick only at the sandwiching portion between and, and the plate thickness is made thin at the portions where the vibrating portion 7 and the lead electrodes 11 and 12 are formed by etching. FIG. 4 clearly shows the diaphragm 1 after this etching step, in which the back surface portion corresponding to the frame line 19 is thinned by etching. Also,
The outer peripheral portion of the frame line 19 is a portion sandwiched and joined by the covers 2 and 3, and as is clear from FIG. 4,
The holding width 20 on the longitudinal side of the diaphragm 1 is made wider than the holding width 21 on the short side.

Further, since the lead electrode 11 is provided on the side of the vibrating portion 7 as shown in FIG.
Are displaced from the center of the diaphragm 1 to one side.

The cut groove 6 in the root portion 10 has a semicircular shape as shown in FIG. 4, so that cracks are less likely to occur even when an excessive impact is applied.

This is because the atoms constituting the crystal have more binding sites in the plus X direction than in the minus X direction.

When etching is carried out, the molecules of the etching solution are bound to the binding sites thereof, thereby separating the atoms constituting the crystal.

When the tip side of the vibrating portion 7 is in the plus X direction as in this embodiment, many bonding sites are exposed on the surface of the tip portion facing the kerf 6. Therefore (on the contrary, there are few bonding sites exposed on the surface facing the tip through the kerf 6), the tip side of the vibrating portion 7 is effectively etched by etching, and as a result, The work-affected layer will be surely removed. Since more bonding sites are exposed in the width direction of the vibrating portion 7, that is, in the Z direction, the work-affected layer in that portion can be surely removed by this etching.

What is important in the above construction is that in the present embodiment, the tip side of the tongue-shaped vibrating portion 7 is set in the plus X direction, and the cut groove 6 portion is etched in that shape. That is, the cut groove 6 is formed by sandblasting to form the tongue-shaped vibrating portion 7, but at this time, a work-affected layer is formed on the outer periphery of the vibrating portion 7.

Since this work-affected layer is one in which the crystallinity of quartz is lost, if it remains as it is, the overall vibration characteristics will deteriorate. Therefore, in this embodiment, the work-affected layer is removed by etching the outer periphery of the vibrating portion 7 in the cut groove portion 6. At this time, the vibrating section 7
It is extremely important that the tip end side of is in the plus X direction. That is, in the crystal, when the plus X direction and the minus X direction are compared, the growth in the plus X direction is several times (for example, 5 to 6 times) larger.

[0016]

As described above, according to the present invention, the diaphragm and the first and second covers that cover the front and back surfaces of the diaphragm and sandwich the outer peripheral portion of the diaphragm by the outer peripheral portion thereof are provided. Prepare,
The vibrating plate has a tongue-shaped vibrating portion inside the sandwiched portion by the first and second covers. Electrodes for excitation are provided on the front and back surfaces of the vibrating portion, and the outer peripheral portion of the vibrating portion is provided. Has an etching surface formed by an etching solution, and the tongue-shaped vibrating portion has its tip end side in the plus X direction.

Therefore, the work-affected layer on the outer periphery of the tongue-shaped vibrating portion is effectively removed by the etching solution,
The characteristic deterioration of the vibrating section does not occur.

[Brief description of drawings]

FIG. 1 is a perspective view of one embodiment of the present invention.

FIG. 2 is an exploded perspective view thereof.

FIG. 3 is an exploded perspective view of the same.

FIG. 4 is a top view of the diaphragm.

5 is a cross-sectional view taken along the line AA of the vibrator in which the covers 2 and 3 are joined to the diaphragm of FIG.

6 is a cross-sectional view taken along the line BB of the vibrator in which the covers 2 and 3 are joined to the diaphragm of FIG.

[Explanation of symbols]

 1 Vibration Plate 2 Cover 3 Cover 7 Vibrating Part 8 Excitation Electrode 9 Excitation Electrode 10 Root Part 11 Lead Electrode 12 Lead Electrode 14 Connection Part 15 Connection Part

Claims (2)

[Claims] 1. A diaphragm, comprising: a diaphragm; first and second covers that cover the front and back surfaces of the diaphragm and sandwich the outer peripheral portion of the diaphragm with the outer peripheral portion thereof. There is a tongue-shaped vibrating portion inside the sandwiched portion by the first and second covers. Excitation electrodes are provided on the front and back surfaces of this vibrating portion, and the outer peripheral portion of this vibrating portion is etched with an etching solution. The tongue-shaped vibrating portion forming a surface is a vibrator whose tip side is in the plus X direction. 2. A vibrating plate, and first and second covers that cover the front and back surfaces of the vibrating plate and sandwich the outer peripheral part of the vibrating plate at the outer peripheral part thereof. A tongue-shaped vibrating portion is provided inside the sandwiching portion by the first and second covers, and excitation electrodes are provided on the front and back surfaces of the vibrating portion, and the tip side of the tongue-shaped vibrating portion is a plus X. A method of manufacturing a vibrator, in which the outer periphery of the tongue-shaped vibrating portion is etched with an etching solution.