JP4064189B2 - End face processing method of crystal unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an end face processing method for a crystal resonator that processes an end face of a crystal piece into an inclined surface such as a bevel, and more particularly to an end face processing method that improves productivity.
[0002]
[Prior art]
BACKGROUND OF THE INVENTION A crystal resonator is recognized as a frequency control element, and is incorporated in an oscillator, for example, and widely used as a reference source for frequency and time. In general, although depending on the size of the crystal piece 1, when the vibration frequency is about 30 MHz or less, the bevel or convex end face processing is applied to maintain the vibration characteristics well.
[0003]
(Example of Prior Art) FIG. 4 is a diagram of a crystal resonator for explaining one conventional example.
The crystal resonator is composed of a rectangular crystal piece 1 having an AT cut. And an inclined surface is provided in the both ends of a longitudinal direction. In general, as shown in FIG. 5, a crystal piece 1 and an abrasive 3 are put into a spherical cylinder 2 and rotated. Then, both ends in the longitudinal direction of the crystal piece 1 are shaped to follow the inner diameter of the spherical cylindrical body 2. However, it is drawn on a straight line in the figure for simplicity. It should be noted that electrodes (not shown) are formed on both main surfaces of the crystal piece 1 and are held and accommodated in a sealed container to constitute a crystal resonator.
[0004]
[Problems to be solved by the invention]
(Problem of the prior art) However, in the end face processing method having the above-described configuration, there is a problem that productivity decreases as the size of the crystal piece 1 decreases. That is, in recent years, miniaturization has progressed, and the crystal piece 1 itself in the same frequency band is also processed to be small.
[0005]
For example, when the inclined surfaces having the same radius of curvature are formed at both ends of the crystal piece 1 in order to maintain the vibration characteristics satisfactorily by the similar reason, the spherical cylindrical body 2 is also reduced in proportion to the size of the crystal piece 1. . Therefore, the number of crystal pieces 1 to be put into the spherical cylinder 2 is drastically reduced.
[0006]
Further, the momentum (movement distance) of the crystal piece 1 due to the rotation of the spherical cylindrical body 2 becomes small, and the processing time becomes long. For these reasons, there is a problem that productivity is reduced in the end face processing using the spherical cylindrical body 2. And there existed a problem that variation became large when processing time became long.
[0007]
(Object of the Invention) An object of the present invention is to provide a method for processing an end face of a crystal resonator with improved productivity and small variations.
[0008]
[Means for Solving the Problems]
According to the present invention, as shown in the claims (Claim 1), the quartz wafer is moved linearly by abutting a V-shaped cutting edge against one principal surface of the flat quartz wafer. The one- dimensional and two- dimensional directions are formed by grinding only from one main surface side, and forming an inclined surface in the crystal wafer that gradually decreases in thickness following the cutting edge in at least one-dimensional direction of the one main surface of the crystal wafer. cut into the after the inclined surface to obtain a plurality of quartz pieces was flat as a longitudinal end portion of the one main surface, ridge portions a plurality of quartz pieces and the flat and barrel polishing A method for processing an end face of a crystal resonator, characterized in that a rounded surface is provided. In such an end face processing method , for example, the cutting edge of the dicing blade may be brought into contact with the quartz wafer with a specified inclined surface, so that the processing time is remarkably shortened. An embodiment of the present invention will be described below.
[0009]
【Example】
FIG. 1 (abc) is a process diagram for explaining the end face machining method of the present invention. In addition, the same number is attached | subjected to the same part as a prior art example, and the description is simplified or abbreviate | omitted.
Here, first, a quartz wafer 4 having a diameter of 3 inches and having a thickness of 83 μm (vibration frequency of about 20 MHz) is prepared. In addition, the external dimension of the crystal piece 1 divided | segmented by the cutting line shown by the thin line shall be 1.5 * 1.0 mm, for example.
[0010]
Next, the cutting edge 5 of the dicing blade that matches the inclined surface (bevel surface) of the end face of the crystal piece 1 and has a symmetry angle α is brought into contact with the notch in the one-dimensional direction from the side surface of the crystal wafer 4. In this case, a part of the thickness is left in contact. Then, the crystal wafer 4 is fed in a one-dimensional direction and ground (cut), and inclined surfaces with an angle α are provided at both ends of each crystal piece 1.
[0011]
Next, the groove bottom left in the one-dimensional direction of the crystal wafer 4 is cut by a dicing blade having a thin blade width, and also cut in a two-dimensional direction in accordance with the external dimensions of the crystal piece 1. Thereby, a plurality of crystal pieces 1 are obtained. Then, a large number of crystal pieces 1 obtained in this way are rounded at the ridge line by, for example, barrel polishing (not shown).
[0012]
With such a processing method, the cutting edge 5 of the dicing blade may be cut in conformity with the inclined surface of the crystal piece 1, so that the processing time can be greatly shortened. Incidentally, in the above-described spherical cylindrical body 2, approximately 500 crystal pieces 1 are put in and it takes a processing time of about 100 hours or more. On the other hand, in this embodiment, since the crystal wafer 4 is only mechanically cut, a processing time of about 10 to 20 hours including barrel polishing is sufficient. And variation can be made small. Further, since the inclined surface is formed only on the main surface of the crystal piece 1, the processing is facilitated.
[0013]
[Other matters]
In the above embodiment, the inclined surface is provided by directly contacting the wide cutting edge 5 in the one-dimensional direction of the crystal wafer 4. However, the cutting edge 5 may be contacted and cut after the cut is provided on the surface in advance. . In this case, since the processing amount is small, cutting is facilitated. Moreover, although the inclined surface was provided in the both ends of the crystal piece 1, it can provide in a two-dimensional direction (4 sides).
[0014]
Further, by cutting one side of the blade edge 5 as an inclined surface and the other side as a straight line, an inclined surface can be formed only on one end side of the crystal piece 1, and these can be arbitrarily selected according to vibration characteristics. . Moreover, although the inclined surface left a part of the thickness of the crystal piece 1, it may be cut as it is. However, since it is easy to break, it is better to cut a part vertically as in the embodiment.
[0015]
Moreover, although it finally cut | disconnected and divided | segmented with the dicing blade with a thin blade width | variety, you may divide | segment by putting a crystal wafer in an etching liquid after end surface processing. In this case, even if a mask is formed on both main surfaces and etching is performed, the etching may be performed directly without providing a mask.
[0016]
Further, for example, the cutting edge 5 can be formed in a circular arc shape and can be formed in a concave shape having dents at both ends of the crystal piece 1 (FIG. 3). In this case, since the inclination from the flat portion becomes steep, the amount of energy confinement is large and a reduction in crystal impedance can be expected. In short, the present invention can shorten the processing time by forming an inclined surface following the blade edge 5 at the end of the crystal piece 1.
【The invention's effect】
According to the present invention , a V-shaped cutting edge is brought into contact with one main surface of a flat crystal wafer, the crystal wafer is moved linearly and ground only from the one main surface side, and the cutting edge is applied to the crystal wafer. In accordance with the above, an inclined surface that gradually decreases in thickness is formed in at least one-dimensional direction of one main surface of the crystal wafer, and is cut in the one-dimensional and two-dimensional directions, and the inclined surface is elongated in the longitudinal direction of the one main surface. after obtaining a plurality of quartz pieces and the one end portion and to plate-shaped, since a plurality of quartz pieces and the flat barrel polishing provided rounded ridge portion, less variation to improve the productivity A method of processing an end face of a crystal resonator can be provided.
[Brief description of the drawings]
FIG. 1 is a process chart of end face processing for explaining an embodiment of the present invention.
FIG. 2 is a diagram of a crystal piece according to an embodiment of the present invention.
FIG. 3 is a diagram of a crystal piece showing another example of the present invention.
FIG. 4 is a front view of a crystal piece for explaining a conventional example.
FIG. 5 is a diagram of a spherical cylinder for explaining a conventional example.
[Explanation of symbols]
1 crystal piece, 2 spherical cylinder, 3 abrasive, 4 crystal wafer, 5 cutting edge.

Claims (1)

A V-shaped cutting edge is brought into contact with one main surface of a flat crystal wafer, the crystal wafer is moved linearly, and is ground only from the one main surface side. Is formed in at least one-dimensional direction of one main surface of the quartz wafer and cut in the one-dimensional and two-dimensional directions, the inclined surface is one end in the longitudinal direction of the one main surface A method of processing an end face of a crystal resonator, comprising: obtaining a plurality of crystal pieces in a flat plate shape, and then barrel-polishing the plurality of crystal pieces in a flat plate shape to provide roundness in a ridge line portion.

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