JPS6322939B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cylindrical crystal resonator.

Rotation Y of AT cut, BT cut, etc. of crystal plate
For thickness-shear resonators using plates, square plates and circular plates are often used when there are no restrictions on external dimensions, especially when preventing leakage of thickness-shear vibration and obtaining a high-Q resonator. Convex-shaped resonators are often used.

Recently, there has been a demand for smaller and thinner crystal resonators for use in small electronic devices and electronic watches, and at the same time, in order to reduce power consumption, crystal resonators with low equivalent resistance are desired. It is rare. A device that satisfies these requirements is, for example, a rectangular plate formed into a convex shape by increasing the dimension of the crystal piece in the direction of vibration change and shortening the dimension in the direction perpendicular to the vibration displacement.

However, in order to obtain such a small oscillator, conventionally, polishing was performed by hand using a semi-concave spherical polishing plate, or a crystal plate was pasted on a semi-convex spherical substrate. Polishing was carried out using a concave spherical polishing plate, but the machining itself was difficult due to the small size of the vibrator, resulting in very large variations in size.

The present invention has been made in view of the above points,
The object of the present invention is to provide a method for easily and accurately manufacturing a small-sized vibrator that satisfies the above-mentioned requirements.

That is, in the present invention, a rectangular crystal plate is pasted on the outer peripheral surface of a cylindrical body with a radius of R, and the crystal plate and the grindstone are brought into contact with this cylinder and a cylinder whose outer peripheral surface is formed of a grindstone at least. The main plane of the crystal plate is processed into a curved surface with a curvature of R, and then r<R
A processed crystal plate is pasted on the outer circumferential surface of a cylindrical body with a radius r under the conditions of The crystal plate is characterized in that chamfered portions with a curvature r are formed at both ends, and then the crystal plate is cut into a predetermined size.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the main parts of the manufacturing apparatus used in this embodiment, and a rectangular crystal plate (for example, an AT cut plate) 3 is attached to the outer peripheral surface of a cylindrical body 1 having a radius R. Further, an outer diameter grinder 6 is disposed near the cylindrical body 1 and uses a cylindrical body 5 whose outer peripheral surface is formed by a grindstone 4 as a processing means. and 8
They are rotating in the same direction as shown in . In such a state, when the crystal plate 3 and the grindstone 4 are brought into contact, the outer surface of the crystal plate 3 is ground by the grindstone 4, a curved surface with a curvature R is formed on one main surface of the crystal plate 3, and a planar surface is formed. A convex-shaped crystal plate is obtained. At this time, while reciprocating at least one of the cylindrical body 1 and the outer diameter grinder 6 in the X-X' direction, the distance between the cylindrical body 1 and the outer diameter grinder 6 is narrowed by a minute interval each time. (hereinafter referred to as traverse motion), the grinding process can be performed more quickly and efficiently.

Next, the planoconvex-shaped crystal plate 3 obtained in the first grinding process is attached to the cylindrical body 1 again with the machined surface facing inside, and the grinding process is performed again using the outer diameter grinding machine 6. A double convex crystal plate 10 having curved surfaces with a curvature R on both sides as shown in FIG. 2 is obtained.

Next, this double convex type crystal plate,
Furthermore, it is pasted on the outer circumferential surface of a cylindrical body with radius r under the condition of r<R, and using the manufacturing apparatus shown in Fig. 1, the curvature R
A cylindrical crystal plate 20 as shown in FIG. 3 is obtained by chamfering with a curvature of r in the same manner as in the case of forming the curved surface. In addition, in Figure 3,
21 is a main surface processed with a curvature of R, and 22 is a chamfered portion processed with a curvature of r. By cutting the thus obtained crystal plate 20 to an appropriate width in the Y-Y′ direction shown in FIG. 3, a cylindrical crystal resonator 30 having a small equivalent resistance and having a shape shown in FIG. can get.

In the above embodiment, when selecting a grindstone, since quartz is a hard material with a hardness of 7, it is desirable to use a grindstone containing diamond abrasive grains. Furthermore, the particle size of the abrasive grains is #500 to #2000.
It is desirable that it be within the range of #500, and if it is larger than #500, problems will occur with respect to the quartz plate during processing. For the same reason, it is desirable that the feed of the grindstone be 10 μm or less per reciprocating traverse movement.

Specific examples of the present invention will be shown below.

An AT with a length of 10 mm, a width of 8 mm, and a thickness of 0.43 mm is placed on the outer peripheral surface of a cylindrical body with a curvature R of 80 mm and a length of 50 mm.
Using an outer diameter grinder equipped with a grindstone containing #600 diamond abrasive grains, 30 pieces of cut rectangular crystal flat plates were pasted, and the cylindrical body was rotated and traversed while the cylindrical body was rotated and traversed to a diameter of 3 μm per reciprocating traverse.
Machining was carried out by adjusting the feed of the external diameter grinder so that the cutting depth was , and a double convex type crystal plate was obtained.

Next, this double convex type crystal plate,
Furthermore, 15 pieces were attached to the cylindrical surface of a cylinder with a curvature r of 30 mm and a length of 50 mm, and similarly processed using a #600 diamond grindstone to obtain cylindrical crystal plates with very good surface precision. .

This cylindrical crystal plate was cut with a diamond cutter to a width of 2.4 mm, and the required etching and electrode deposition were performed to adjust the resonance frequency.
We obtained 180 small rectangular cylindrical crystal resonators with a frequency of 3.9MHz and an equivalent resistance of 50Ω or less.

As described above, according to the present invention, cylindrical crystal resonators with very good surface precision, small size, and low equivalent resistance can be easily manufactured in large quantities at one time, and therefore have great industrial value. be.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the main parts of the manufacturing equipment used in the present invention, Figures 2 and 3 are perspective views of double convex type and cylindrical crystal plates obtained by the equipment shown in Figure 1, and Figure 4. 1 is a perspective view of an example of a small cylindrical crystal resonator obtained according to the present invention. 1... Cylindrical body, 3, 10, 20... Crystal plate, 4
. . . Grindstone, 6 . . . External diameter grinder, 21 .

Claims (1)

[Claims] 1. A rectangular flat crystal plate is attached to the outer peripheral surface of a first cylindrical body having a radius of R, and a second cylinder whose at least the outer peripheral surface is formed of a grindstone is attached to the first cylindrical body. The body is rotated with the crystal plate and the grindstone in contact with each other to process one main plane of the crystal plate into a curved surface with a curvature R, and then similarly process the other main plane into a curved surface with a curvature R.
Next, the crystal plate is pasted on the outer peripheral surface of a third cylindrical body with a radius r under the condition r<R, and is brought into contact with the second cylindrical body in a rotating state again. , curvature R of one main plane of the crystal plate
A chamfered portion with a curvature r is formed at both ends of the quartz crystal plate, and a chamfered portion with a curvature r is further formed at both ends of the other main plane with a curvature r, and then this crystal plate is cut into a predetermined size. A method for manufacturing a cylindrical crystal resonator. 2 The first cylindrical body and the second cylindrical body, and the second cylindrical body and the third cylindrical body are relatively moved in the rotation direction, and the distance between the respective cylindrical bodies is changed in the rotation axis direction. 2. The method of manufacturing a cylindrical crystal resonator according to claim 1, wherein the distance is narrowed by a minute distance each time the cylindrical crystal resonator is moved.