JPS63139601A - Surface machining for linbo3 single crystal - Google Patents

Abstract

PURPOSE:To improve flatness and surface roughness of a cut surface, by a method wherein surface cutting is effected so that a cutting direction can be specified in a direction in which machinability is most excellent. CONSTITUTION:When a workpiece 2 is secured to a work holder 4, provided the advancing direction of the workpiece 2 is B and a radial direction extending toward the rotation center of a main shaft 1 is A, a cutting direction C is extended in reverse direction to the advancing direction B, and an angle of the cutting direction with an axis Y is set to 60 deg.. The holder 4 is secured to the tip of the main shaft 1, clockwise rotation is exerted on the main shaft 1, and a feed from the outside of the workpiece 2 toward a center is exerted, as shown by an arrow mark, on a bite 3 having a diamond tip 3a. As noted above, by performing a cutting work in a way that the cutting direction c is specified, uniform and excellent flatness and surface roughness can be provided. An angle of the direction C with the axis Y may be set to 180 deg. or 300 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to LiNb0. This paper relates to a method for finishing two cut surfaces of a single crystal, and is concerned with turning processing to obtain good flatness and surface roughness.

(Prior Art) FIG. 5 is a diagram showing a conventional plane machining method. In the figure, 1 is the main shaft of a lathe, 2 is a workpiece (1, a2a is the pre-machined surface, and 2b is the lathe-machined surface that requires flatness and good surface roughness. 3 is the lathe turning tool, which usually has a diamond tip at its tip. 3a.The movement of the cutting tool 3 is such that the position of the tip of the tip 3a forms the turning surface 2b, and the cutting tool 3 is fed linearly at right angles to the rotation axis of the main shaft 1 as shown in the figure. Then, the pre-machined surface 2a is sequentially turned from the outer periphery of the workpiece 2.

[Problem that the invention seeks to solve]

The conventional plane turning method for two-cut surfaces of L i N b Os single crystal has the rotation center of the main axis l within the plane of the workpiece 2, and the linear movement of the cutting tool 3 and the rotation of the workpiece 2 For example, in a previous report (1985 Institute of Electronics and Communication Engineers General Conference Preprint Collection 995), the surface roughness was very poor. The crystal is a 3m school of fish and has a hexagonal plane (10TT), so the cutting characteristics depend on the crystal orientation depending on the cutting direction. Therefore, if the center of rotation is within the plane of the workpiece 2, the tip 3 of the cutting tool 3
The cutting direction a is rotated by 360@ around the rotation axis of the main spindle, and as shown in FIG. It is divided by 3 minutes ·, + ( by 120'' period.

Further, in FIG. 6, a difference in level between portions D and E occurs on the order of several tenths of a micron, and the flatness also decreases.

This was a particularly big problem when finishing the cutting process 2b with good flatness and surface roughness.

This invention was made to solve the above-mentioned problems, and is a LiNb0. , the purpose is to obtain a surface turning method for single crystal Z-cut surfaces.

[Means for solving problems]

Isshi α Minato Subanyu 1 Jin and year number ÷.

The method for planar processing of LiNbOs single crystal according to the present invention is a method for flattening LiNbOs single crystal. Considering the crystal orientation dependence of single crystal,
The cutting direction of the cutting tool is set to any one of 60°, 180°, 300°, and ±5° counterclockwise with the +Y direction as a reference.

[Effect]

In this invention, the cutting direction by the cutting tool is set to LiNb
0. Since it is set to be constant in the direction of the single crystal Z-cut surface with the best machinability, after cutting, the cut surface has uniform and good flatness and surface roughness.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a diagram showing a planar processing method for a LiNb 0° single crystal according to an embodiment of the present invention, and in the figure, the same reference numerals as in FIG. 5 indicate corresponding parts. In this embodiment, as a method for keeping the cutting direction constant, a so-called off-axis interrupted turning method in which the rotation center of the main spindle is not within the plane of the workpiece is used.

FIG. 3 is a diagram showing the relationship between the cutting direction and the surface roughness in plane turning of the Z-cut surface of a L i N b Os single crystal.

From Figure 3, 60° counterclockwise with +Y as the reference.

It can be seen that the surface roughness is improved if the cutting direction is set at around 180° and 300°. However, due to the instability of the atmosphere during processing, the above angle is considered to have a range of approximately ±5@.

Next, the operation will be explained. A workpiece 2 having a Z-cut surface of a LiNbO5 single crystal is fixed to a work holder 4 with wax, and a workpiece holder 4 is fixed to the tip of the main spindle 1 by a vacuum chuck using negative pressure. The tip 3a of the cutting tool 3 is made of diamond, and a so-called R cutting tool is used.

The main shaft 1 is given clockwise rotation, and the cutting tool 3 is given a feed from the outside of the workpiece 2 to the center, as shown by an arrow 5 in the figure. The workpiece 2 is fixed to the holder 4 by the method shown in FIG. 2, where A is the radial direction toward the center of rotation, and B is the direction of movement of the workpiece 2 as the main shaft rotates clockwise. Therefore, the cutting direction is the C direction, which is opposite to the B direction. In the embodiment, the angle between the cutting direction and the Y axis is 60 degrees.

By performing the above processing, the cutting direction is constant and is set to the cutting direction with the best machinability, so uniform and good flatness and surface roughness can be obtained. FIG. 4 shows a photograph of a machined surface subjected to plane turning using the above-mentioned processing method.

In the above example, the angle between the cutting direction and the Y axis is 60°.
However, the same effect can be obtained even if the angle is 180° and 300''.

Furthermore, although the interrupted shaft cutting method was used as the cutting method, a similar effect can be achieved by a cutting tool rotating type fly-cut cutting method in which the direction of cutting is constant, and a reciprocating motion type shaping method.

In addition, in the above explanation, the present invention has been described as a case where the present invention is applied to a flat surface cutting method, but it goes without saying that the idea of the present invention can also be widely applied to machining such as grinding and polishing. Needless to say, it can be used not only for flat surfaces but also for high-precision machining of general rotating surfaces such as spherical and aspherical surfaces.

〔Effect of the invention〕

As described above, according to the present invention, in the planar processing method for l,1N bos single crystal, the cutting direction by the cutting tool is set to be constant in the direction with the best machinability, and the planar cutting is performed. After that, there is an effect that the cut surface can be finished uniformly and with good flatness and surface roughness.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a planar processing method for a LiNb0° single crystal according to an embodiment of the present invention, Figure 2 is a diagram showing the direction in which a workpiece is attached to a work holder, and Figure 3 is a diagram showing the cutting direction and surface roughness. Figure 4 is a photograph of the surface when cutting in the cutting direction with good machinability, Figure 5 is a diagram showing the conventional planar machining method, and Figure 6 is a photograph of the surface of LiNbO5 produced by the conventional machining method. This is a photo of the surface. 1 is the main shaft of the lathe, 2 is the workpiece, 3 is the turning tool, 3a is the diamond tip, 4 is the work holder, and 5 is the direction of movement.

Claims (1)

[Claims] (1) In the plane processing method that planes the Z-cut surface of LiNbO_3 single crystal, the cutting direction is set at 60° counterclockwise with the +Y direction as the reference.
, 180°, 300°, each of ±5°.