JPH098581A - Manufacture of vibrator - Google Patents

Abstract

PURPOSE: To prevent the degradation of a characteristic and the cracking of a cover by etching the worked alteration layer made by a sand-blast and eliminating the layer. CONSTITUTION: A diaphragm 1 has a tongue piece shaped vibration part 7 in the holding part by first and second covers 2 and 3. On the surface and rear surface of this vibration part 7, electrodes 8 and 9 for vibration proof are formed. On the side of the vibration part of the covers 2 and 3, recessed parts 2a and 3a are formed. These recessed parts 2a and 3a are formed by further eliminating the surfaces of the recessed parts 2a and 3a up to the depth corresponding to at least one-third of the average grain diameter of abrasive grains to be used for a sand-blast by an etching after the recessed part shapes are formed by the sand blast.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A conventional vibrator of this type includes a vibrating plate and first and second covers which cover the front and back surfaces of the vibrating plate and sandwich the outer peripheral portion of the vibrating plate at its outer peripheral portion. Prepared,
The vibrating plate had a tongue-shaped vibrating portion inside a portion sandwiched by the first and second covers, and excitation electrodes were formed on the front and back surfaces of the vibrating portion. Further, on the surfaces of the first and second covers on the side of the vibrating portion, recesses are formed in order to prevent contact with the vibrating portion.

[0003]

In the above-mentioned conventional example, the recesses of the first and second covers were formed by, for example, sandblasting. However, this formation causes the surface of the recesses to be degenerated with minute cracks. There are layers. as a result,
When a vibrator is impacted or vibrated, the crystal fragments are cut off from the work-affected layer and adhere to the vibrating part, degrading the oscillator characteristics, or cracks from the work-affected layer grow to cover the oscillator. There was a problem of cracking.

Therefore, the object of the present invention is to prevent deterioration of the characteristics of the vibrator and cracking of the cover by removing the work-affected layer formed on the surface of the concave portion of the cover. .

[0005]

In order to achieve this object, the present invention provides a grinding tool used for sandblasting by etching a recess formed in at least one of the first and second covers and then forming the recess by sandblasting. It is formed by removing the surface of the recess to a depth corresponding to at least one-third of the average particle diameter of the particles.

[0006]

With the above-described structure, the work-affected layer on the surface of the recess formed by sandblasting is removed by etching, so that a vibrator which does not change its characteristics and the cover is not cracked can be obtained.

[0007]

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 quartz 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 bonded by directly bonding the crystals. It should be noted that reference numerals 4 and 5 in FIG. 1 denote external electrodes, which are arranged on the diagonal line of the back surface of the cover 3. As shown in FIGS. 2 and 6, concave portions 2a and 3a having a larger area than at least the vibrating portion 7 are formed on the inner surfaces of the covers 2 and 3, so that the vibrating portion 7 and the inner surfaces of the covers 2 and 3 contact each other. It prevents you from doing it.

As shown in FIGS. 2 and 3, the vibrating plate 1 has a U-shaped cut groove 6 formed inward thereof, thereby forming the tongue-shaped vibrating portion 7. . Excitation electrodes 8 and 9 are formed on the front and back surfaces of the vibrating portion 7, and the lead electrodes 11 and 9 are formed through the root portion 10 of the vibrating portion 7, respectively.
12 are pulled out. The end portion of the inner lead electrode 11 penetrates the diaphragm 1 by the through hole 13 as shown in FIGS. 2 to 5, and then the vibrating portion 7 as shown in FIG.
And extends to the opposite side of the root portion 10 to form a connection portion 14. Further, the lead portion 12 has a root portion 10.
The connection portion 15 is formed on the side. Then, through the conductors 18 in the through holes 16 and 17 formed in the cover 3 corresponding to these connecting portions 14 and 15, the external electrodes 4 and 4, respectively.
5 is connected. 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 lead electrode 11
The portion passing through the side of the vibrating portion 7 is joined to the cover 3 on the outside thereof. Then, in this way, on the back surface side of the diaphragm 1, to the side of the vibrating portion 7,
In order to form the lead electrode 11, as is apparent from FIGS. 5 and 6, the vibrating plate 1 is thickened only at the sandwiching part with the covers 2 and 3, and the vibrating part 7 and the lead electrodes 11 and 12 are formed.
The plate thickness of the portion where the is formed is reduced by etching. FIG. 4 shows the diaphragm 1 after this etching process.
The plate thickness of the back surface portion corresponding to the frame line 19 is thinned by etching. Further, the outer peripheral portion of the frame line 19 is a portion which is sandwiched and joined by the covers 2 and 3. As is clear from FIG. 4, the sandwiching width 20 on the longitudinal side of the diaphragm 1 is sandwiched in the short direction. It is wider than the width 21.

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

It should be noted that 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.

Next, a method of forming the recesses 2a and 3a of the covers 2 and 3 will be described. First, a mask is formed on a mirror-finished quartz plate surface so as to cover portions other than the portions where the recesses 2a and 3a are formed. Next, a concave shape is formed by sandblasting. A work-affected layer is formed up to a depth of about one third of the average grain size of the abrasive grains used at this time. Therefore, at least a portion corresponding to this depth is thereafter removed by etching to remove the work-affected layer. Finally, remove the mask. What is important here is the final stripping of the mask. This is to prevent the mirrors of the covers 2 and 3 that are directly bonded to the diaphragm 1 from being roughened by etching and preventing the crystals from being directly bonded to the diaphragm 1.

[0012]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the vibration of at least one of the first cover and the second cover that covers the front and back surfaces of the diaphragm and the outer peripheral portion of the diaphragm is sandwiched by the outer peripheral portion thereof. The plate is provided with a recess on the vibrating part side, and the recess is formed by sandblasting and then etching the surface of the recess to a depth corresponding to at least one-third of the average grain size of the abrasive grains used for sandblasting. It was done.

With the above structure, the work-affected layer formed by sandblasting can be removed by etching, so that it is possible to prevent the characteristics from changing and the cover from cracking.

[Brief description of drawings]

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

FIG. 2 is an exploded perspective view of FIG. 1;

FIG. 3 is an exploded perspective view of FIG.

FIG. 4 is a top view of the diaphragm of FIG.

5 is a sectional view of the vibrator in which covers 2 and 3 are joined to the vibrating plate of FIG.

6 is a cross-sectional view of the vibrator in which covers 2 and 3 are joined to the vibrating plate of FIG. 4;

[Explanation of symbols]

 1 Vibration Plate 2 Cover 2a Recess 3 Cover 3a Recess 7 Resonator 9 Excitation Electrode 10 Root 11 Lead Electrode 12 Lead Electrode 14 Connection 15 Connection

Claims (1)

[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 periphery of the diaphragm with the outer periphery thereof. The first and second covers have a tongue-like vibrating portion inside the nipping portion, and excitation electrodes are formed on the front and back surfaces of the vibrating portion.
In a vibrator in which at least one of the first and second covers has a concave portion on the vibrating portion side, in the concave portion, after the concave portion is formed by sandblasting, at least 3 of the average particle diameter of abrasive grains used for sandblasting is obtained by etching. A method of manufacturing a vibrator, which is formed by removing the surface of a recess to a depth equivalent to one-half.