JPH0325966B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric plate processing method suitable for mass production. A typical example of a piezoelectric plate is a quartz plate, which is used as a quartz resonator by disposing predetermined excitation electrodes on the quartz plate. In order to meet the recent demand for miniaturization of crystal resonators, rectangular crystal plates are used for those with oscillation frequencies of 1 MHz or higher, and tuning fork-shaped crystal plates are used for those with oscillation frequencies of several KHz to several hundred KHz. . Figure 1a shows a crystal resonator using a rectangular crystal plate 1. The long side of the main surface of this crystal plate 1 is parallel to the X axis, the short side is parallel to the Z' axis, and the long side is parallel to the Z' axis. both sides of the direction
It is machined at an angle α=1 to 16° with respect to the Y′ axis. Note that this crystal resonator has excitation electrodes 2 and 3 arranged opposite to both main surfaces of a crystal plate 1, and applies a high frequency voltage corresponding to an oscillation frequency inversely proportional to the thickness of the crystal plate 1 to the excitation electrodes 2 and 3. Thickness shear vibration is produced by applying By the way, the Z′ axis is
Similar to the Y' axis, it is the crystal axis obtained by rotating the Z axis (the same goes for the Y axis) around the X axis by an angle θ = 34° to 36°, as shown in Figure 1b, and this X-Z' A crystal plate parallel to the axial plane is called an AT-cut crystal plate. The inclination angle α of both side surfaces of the crystal plate 1 has the effect of suppressing undesired contour shear vibrations that occur in addition to desired thickness shear vibrations, thereby improving frequency-temperature characteristics.

However, as the main stage for processing such an inclined side surface, a single crystal blank 4 cut parallel to the X-Z′ axis plane and processed into a rectangular shape is prepared as shown in FIGS. 2a and b. Then, both sides in the X-axis direction, which is the long side direction, are cut at an inclination angle α from the Y' axis, which is the normal direction of the crystal plate 4. Generally, piezoelectric plates such as crystal plates are cut. When cutting, it is necessary to cut in the normal direction of the plane of the piezoelectric plate, and it is difficult to cut at an angle of inclination α.Therefore, it is difficult to mass produce piezoelectric plates such as quartz plates with inclined sides. I couldn't do it.

The present invention has been made to solve the above problems, and its gist is to provide a piezoelectric plate processing method for obtaining a piezoelectric plate having a predetermined thickness dimension. , the main surfaces of the piezoelectric plates are processed into substantially the same quadrilateral shape, and the main surfaces of the piezoelectric plates are arranged at the same angle as the predetermined angle when cutting at least two or more of the piezoelectric plates. After temporarily bonding each other, the piezoelectric plates are cut at a predetermined angle and interval on the one end face toward one end face perpendicular to the temporarily bonded surface of the piezoelectric base plates,
Next, this is a piezoelectric plate processing method in which a large number of piezoelectric plates are simultaneously obtained by peeling off the temporary adhesive.

FIG. 3 shows a method of processing a crystal plate according to an embodiment of the present invention. Crystal blank plates 41, 42, 43 of this example,
...is approximately 100 pieces (only 7 pieces are shown in the drawing).
In both cases, two opposing sides of the four sides are made parallel to the X-axis direction and the Z'-axis direction, and the lengths of each of the two sides in the X-axis direction and the Z'-axis direction are set to a predetermined value (in this example :8 mm and 50 mm), and the thickness (dimension in the Y' axis direction) to a predetermined value according to the desired oscillation frequency (this example:
Processed by cutting, polishing, etc. into a four-sided plate with a diameter of 0.4 mm at 4 MHz. These crystal blanks 41, 42, 43, . . . are subjected to surface treatments such as etching and cleaning to remove the processed layer as necessary, and are temporarily coated with a thin layer of processing wax 5 etc. on each main surface. Glue. When temporarily bonding, it is preferable that both end faces in the X-axis direction are aligned on the same Y'-Z'-axis plane, in order to produce the same shape when cutting as described later.

Next, one end face perpendicular to the temporarily bonded surface, that is, facing the upper Y'-Z' axis plane in the drawing, is perpendicular to the same plane as shown by the arrow,
These crystal blanks 41, 42, 43, . . . are cut by a cutting machine such as a wire saw or a band saw at a predetermined angle α (α=5° in this example) from the Y' axis. Then, at a predetermined interval W (2 mm in this example),
Cut by moving parallel to the Z′ axis direction.

Next, the cut crystal plates 61, 62, 63,...
... is shown in FIG. 3b, the temporarily bonded varnish 5 is peeled off using a release agent such as methyl, ethyl, ketone, etc., and a large number (approximately 100 in this example) of crystal plates 61,
62, 63, ... are obtained.

According to the above processing method, each dimension of the crystal base plate and the crystal plate processed from it is arbitrarily selected,
In particular, the angle α can be arbitrarily selected and cutting can be performed perpendicularly from one end face, and the range of its use is vast.

Next, as a processing method to reduce the notches that cannot be used effectively at the beginning and end of cutting, as shown in FIG. 4, crystal blanks 41, 42, 43, .
The main surface (X-Z' axis plane) of What is necessary is to temporarily bond them by arranging them at the same angle as the predetermined angle α.

In the above examples, as the material of the piezoelectric plate
AT cut crystal was used, but BT, DT, CT,
In addition to other cut crystals such as GT, NT, and +5°X, piezoelectric materials such as lithium tantalate and lithium niobate may also be used, and the shape is not limited to the rectangular shape of the example, but also square, square, etc. Any shape having both side surfaces, such as a tuning fork shape, can be used.

As described above, the present invention provides a method for processing a piezoelectric plate having sloped surfaces on both sides, which is suitable for mass production, and therefore has great utility value.

[Brief explanation of drawings]

FIG. 1 shows a crystal resonator having inclined surfaces on both sides, and FIG. 1A is a perspective view, and FIG. 1B is a diagram showing crystal coordinate axes. FIG. 2 shows cutting by a conventional method, in which FIG. 2A is a perspective view and FIG. 2B is a side view. FIG. 3 shows a method of processing a crystal plate according to an embodiment of the present invention, and FIG. Figure b is a perspective view showing the quartz plate after cutting. FIG. 4 shows another embodiment of the present invention, and is a perspective view showing a state when cutting at a predetermined angle α after temporary adhesion. 41, 42, 43, ~ 47...Crystal plate, 5...
...Varnish, 61,62,63,~,67...Crystal plate, α...Angle, W...Space.

Claims (1)

[Claims] 1 Cut the piezoelectric plate into a rectangular shape, and set the slope angle α on the side surface.
In a method of processing a piezoelectric plate to obtain a piezoelectric plate tilted at a certain angle, the main surface is processed into substantially the same quadrilateral shape with a predetermined thickness dimension, and at least two or more of the piezoelectric plates are cut. After arranging the piezoelectric plates at the same angle as the predetermined angle and temporarily bonding the main surfaces of the piezoelectric plates to each other, one A method for processing a piezoelectric plate, which comprises cutting the piezoelectric plate at predetermined angles and intervals on the end face, and then peeling off the temporary adhesive to obtain a large number of piezoelectric plates at the same time.