JPS632164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a large quantity of crystal blanks used as convex width-slip oscillators at one time.

Generally, for a crystal resonator in the frequency band of 500kHz to 2000kHz, the vibration mode used is contour shear vibration in the low frequency band, and thickness shear vibration in the high frequency band. For the normally used square profile shear resonator, the crystal plate becomes small in the above frequency band, causing deterioration of electrical characteristics due to the influence of the support wire, and for thickness shear resonators, it is necessary to improve the electrical characteristics. The crystal plate becomes significantly larger, and each has its advantages and disadvantages.

In order to overcome these shortcomings of the conventional technology, we have developed a rectangular crystal plate as a crystal resonator that can firmly hold the crystal plate without adversely affecting the electrical characteristics and can be made smaller. A crystal resonator in which energy is trapped by removing the edges of the crystal has already been published as JP-A-52-105795.

The present invention provides a method for simultaneously processing a large number of crystal blank plates for the above-mentioned crystal resonator.

Hereinafter, a conventional example and the present invention will be explained in detail using the drawings.

Figure 1 shows a crystal plate used in a convex width slip crystal resonator. A is a planoconvex crystal blank, and b is a biconvex crystal blank. As shown in the figure, one or both long sides (Figure 1a) or both (Figure 2b) of the long sides of a rectangular crystal blank plate are processed into an arc shape, and the maximum width w is approximately half the length ( 1/2). Since the processing method for both a and b is basically the same (for example, in the case of b, a curved surface may be formed on the opposite side of a), an example of the case of a will be described below. Convex processing of rectangular crystal blanks has traditionally been the second
The process is carried out using a curved surface processing lap machine N having a curved surface polishing plate as shown in the figure.

This curved surface machining lap machine uses a polishing dish 2 around which a concave part 1 machined with a radius of curvature R is provided, and while rotating it, a jig 4 on which a crystal blank plate 3 is attached is coated with polishing sand. Convex processing is performed on the long sides of the crystal blank by bringing it into contact with the attached concave portion 1. b is an enlarged view of a.

On the other hand, when manufacturing a crystal resonator, it is important to consider economic efficiency as well as performance. Therefore,
It is inefficient to process the crystal plates one by one as described above, and in order to achieve economic efficiency, it is necessary to process a plurality of crystal blank plates at the same time.

Now, in order to manufacture multiple crystal blanks using the curved surface processing lap machine shown in Fig. 2, as shown in Fig. 3, a large number of crystal blanks are glued together to form a block. A method of grinding is considered, but with this method, the distance from the center of the polishing disk is different between the center part (part a) and both ends (part b) of the block, so it is difficult to obtain the same crystal blank shape. It disappears.

That is, in the center part a, the maximum width w is approximately 1/2 as shown in FIG. It has the disadvantage that w deviates from the 1/2 position.

When a crystal resonator is manufactured using the crystal plate shown in Fig. 4, the vibration displacement is approximately zero at the (x) end, but because it vibrates at the (y) end. If this portion is supported, the support loss will be large, leading to a significant drop in Q.

Therefore, in a crystal resonator that convexly processes a rectangular crystal plate to trap energy, the first
As shown in the figure, it is essential to process so that the maximum width w is approximately 1/2.

Therefore, in order to process multiple crystal blanks at the same time as shown in Figure 1a using the curved lapping machine shown in Figure 2, each crystal blank should be placed at the same distance from the center of the polishing plate. This requires a lot of work to bond the crystal blanks, which is inefficient.

It is necessary to prepare a polishing plate each time the radius of curvature changes.

It is necessary to correct the curvature of the concave portion of the polishing plate as appropriate.

There were other problems.

The purpose of the present invention is to eliminate the above-mentioned problems and provide a method for simultaneously manufacturing a large number of convex width sliding crystal plates for crystal resonators that always have a constant shape. In the method for manufacturing a crystal blank for a width-slip crystal resonator in which energy is trapped by a crystal resonator, a plurality of rectangular crystal blanks are glued together to form a block, and the block is held at a predetermined position with respect to a grinding wheel. It is attached to the tip of an arm that reciprocates vertically with a radius of curvature.
This is achieved by a method for manufacturing a crystal blank for a convex width sliding crystal resonator, characterized in that the curved surface of the block is processed by the grinding wheel.

FIG. 5 shows an outline of the processing procedure according to the present invention.

A crystal block b is created by gluing a plurality of rectangular crystal blank plates a, and this is glued to a predetermined jig c.

When the crystal block b bonded to the jig c is attached to a curved surface processing machine (described later) and ground until the maximum width w of the crystal blank plate reaches a predetermined dimension, a curved crystal block d is completed.

Thereafter, the adhesive is melted and the crystal blank is removed from the crystal block to complete the processed crystal blank e.

Next, an example of an apparatus for carrying out such a manufacturing method is shown in FIG. 6a. FIG. 6b is an enlarged view of the tip of the arm during curved surface machining.

In this figure, the height of the center of the grinding wheel 4 and the fulcrum of the arm 7 are the same. The moving table 9 is composed of a motor 8, a cam mechanism (not shown), and an arm 7, and the main parts of the curved surface processing machine are installed therein. When the motor 8 is rotated, the cam mechanism operates, and the arm 7 starts reciprocating up and down along a locus of radius R.

Next, the grinding wheel is initially set at a distance from the crystal block 5, but by operating the handle (not shown) and gradually moving the movable table 9 closer to the grinding wheel 4, grinding can be performed. Become.

If the width of the grinding wheel is smaller than the width of the crystal block as shown in Figure 6b, the moving table is moved little by little in the direction of the arrow by operating the handle (not shown) until the entire crystal block is curved. It would be good if it could be processed.

As explained in detail above, according to the present invention, a plurality of crystal blanks are glued together to form a block, and this is attached to the tip of an arm that moves up and down with a predetermined radius of curvature with respect to the grinding wheel. Since convexation is performed, multiple crystal blanks can be produced at the same time, which has a great effect on making convex width shear oscillators more economical.

Furthermore, even if the radius of curvature changes, it can be easily handled by replacing the arm, and the radius of curvature can be precisely machined, which has great advantages.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a convex crystal blank plate, Fig. 2 is a schematic diagram of a curved surface processing lap machine, and Fig. 3 is a schematic diagram of a convex crystal blank plate.
The installation diagram when processing multiple crystal blank plates, Figure 4 is a schematic diagram of a crystal blank plate with the maximum width position shifted from the center point,
FIG. 5 is a diagram showing a procedure for machining a curved surface of a crystal block according to the present invention, and FIG. 6 is a schematic diagram of a curved surface machining apparatus according to the present invention.

Claims (1)

[Claims] 1. In the method for manufacturing a crystal blank of a width-slip crystal resonator in which the edge of a rectangular crystal blank is processed and removed to trap energy, a plurality of rectangular crystal blanks are glued together to form a block. configure,
A convex width sliding crystal oscillator characterized in that the block is attached to the tip of an arm that reciprocates in the vertical direction with a predetermined radius of curvature with respect to a grinding wheel, and the curved surface of the block is processed by the grinding wheel. Method for manufacturing crystal blanks for use.