JP2009262305A - Method and device for cutting single crystal sapphire substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for cutting a single crystal sapphire substrate accurately in the direction of from parallel to within 1° relative to a (1-102) surface (r surface) of a single crystal sapphire with a super abrasive grain wire saw. <P>SOLUTION: The direction of cutting of the super abrasive grain wire saw is from parallel to within 5° relative to the (1-102) surface (r surface) of the single crystal sapphire, and the running direction of the super abrasive grain wire saw is from parallel to within 5° relative to the (11-20) surface (a surface) of the single crystal sapphire. An accurate single crystal sapphire substrate having the r surface as a main surface is thereby provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method of cutting a single crystal sapphire substrate with a superabrasive wire saw with high accuracy in a direction parallel to (1-102) plane (r-plane) or within 1 degree from the parallel, and the superabrasive wire saw cutting. It relates to the device.

Single crystal sapphire is a single crystal of α-AL2O3, and has excellent physical characteristics, thermal characteristics, electrical characteristics, and optical characteristics. Therefore, wear-resistant parts, heat-resistant parts, optical parts, electrical -Widely used for electronic parts, semiconductor parts, etc.
The crystal structure of the single crystal sapphire belongs to the dense hexagonal system, and according to the plane orientation shown in FIG. 2, there is a (0001) plane (referred to as c-plane) in a direction perpendicular to the c-axis of the single crystal. (11-20) plane (referred to as a-plane) parallel to the axis, (1-102) plane (referred to as r-plane) and (11-23) (referred to as n-plane) having a certain angle with respect to the c-axis ) Exists.

As a superabrasive wire saw, a diamond wire saw of a fixed abrasive system in which diamond abrasive grains are fixed to a core wire has been proposed. This diamond wire saw has a very good sharpness, no slurry required, and water-soluble or water-insoluble grinding fluid can be used, so that dirt on the machine and its surroundings is reduced and the working environment can be improved. . Moreover, since a diamond wire saw having a length of several tens of kilometers or more can be manufactured, it can be cut with a multi-piece, and has a feature that a cutting speed several times or more can be obtained as compared with a multi-wire saw using slurry. The fixed abrasive diamond wire saw is made of polyethylene, nylon, polyester, or the like, or a material reinforced with glass fiber or carbon fiber. The core wire has diamond abrasive grains on the outer periphery of the core wire. Or what adheres by electrodeposition is proposed.
(For example, see Patent Document 1)
As another diamond wire saw, a carbon fiber, an aramid fiber, an alumina fiber, a boron fiber, a silicon carbide fiber, or a monofilament or a multifilament such as a silicon-titanium-carbon-oxygen-based inorganic fiber is used as a core wire, and the outer periphery of the core wire A diamond abrasive grain fixed by plating or a synthetic resin binder has been proposed.
(For example, see Patent Document 2)

These superabrasive wire saws can be used in the cutting apparatus shown in FIG. 3 as an example. A superabrasive wire saw cutting device is a device that slices a workpiece into a plurality of pieces at a time while pressing a number of superabrasive wire saws against the workpiece and reciprocating the superabrasive wire saw. Attempts have been made to use superabrasive wire saw cutting equipment not only for single crystal sapphire, but also for slicing silicon wafers from large diameter silicon gots, cutting magnetic materials such as ferrite and neodymium magnets, and cutting optical glass. ing.
Specifically, as shown in FIG. 3, grooves are provided on the outer peripheral surfaces of the main rollers 5 and 6 in accordance with the cut dimensions of the workpiece. The superabrasive wire saw 1 is wound around the outer peripheral surfaces of the reels 2 and 9. The superabrasive wire saw 1 taken out from one reel 2 via the guide rollers 3 and 4 is sequentially wound around the grooves of the main rollers 5 and 6, and is wound around the other reel 9 via the guide rollers 7 and 8. It is wound up. While the superabrasive wire saw 1 is reciprocated between the reels 2 and 9, a large number of superabrasive wire saws 1 are pressed against the work piece 10 to cut the work piece 10 into a large number at a time. At this time, the grinding liquid is supplied from the nozzles 11 and 12 to the grooves of the main rollers 5 and 6.

As a prior document on a method for cutting a single crystal sapphire substrate, a method for cutting a single crystal sapphire substrate having a (0001) plane (c-plane) as a main surface is known.
(For example, see Patent Document 1)

Japanese Patent Laid-Open No. 8-126953 JP-A-9-155631 JP 2003-320521 A

When cutting a single crystal sapphire substrate using a superabrasive wire saw, the cutting progresses along a crystal surface with good machinability compared to a loose-abrasive wire saw, and there is a tendency to greatly affect the cutting accuracy. It is done. For example, when cutting a single crystal sapphire within 1 degree from parallel to the (1-102) plane (r-plane) using a superabrasive wire saw, the traveling direction of the superabrasive wire saw is arbitrary with respect to the crystal plane When set in a different direction, there was a problem that cutting was not possible in parallel.
Accordingly, an object of the present invention is to enable high-accuracy cutting in a direction within 1 degree from parallel to the (1-102) plane (r-plane) in cutting with a superabrasive wire saw on a single crystal sapphire substrate. The present invention provides a cutting method and a cutting device for the same.

A method for cutting a single crystal sapphire substrate according to the present invention is a method for cutting a single crystal sapphire substrate having a (1-102) plane (r-plane) as a main surface by using a superabrasive wire saw. Cutting direction is within 1 degree from parallel to the (1-102) plane (r-plane), and the traveling direction of the superabrasive wire saw is within 5 degrees from parallel to the (11-20) plane (a-plane). A method for cutting a single crystal sapphire substrate with a superabrasive wire saw.
Here, the (1-102) plane (r-plane) being a main plane refers to a single crystal sapphire substrate having an angle parallel to the r-plane or having an angle within 1 degree from the parallel to the r-plane.

A single crystal sapphire substrate cutting device according to the present invention is a superabrasive wire saw cutting device used for cutting a single crystal sapphire, the means for holding the single crystal sapphire, and (1 -102) means for setting the plane (r-plane) within 1 degree from parallel to the cutting direction of the superabrasive wire saw, and (11-20) (a-plane) of the single crystal sapphire It has a means for setting within 5 degrees from parallel to the running direction.

The cutting direction of the superabrasive wire saw is within 1 degree from parallel to the (1-102) plane (r-plane), and the traveling direction of the superabrasive wire saw is parallel to the (11-20) plane (a-plane). Is set within 5 degrees, the single crystal sapphire substrate having the (1-102) plane (r-plane) as the main surface can be cut with high accuracy.

A feature of the method for cutting a single crystal sapphire substrate according to the present invention is a method for cutting a single crystal sapphire substrate having a (1-102) plane (r-plane) as a main surface using a superabrasive wire saw. The cutting direction is within 1 degree from parallel to the (1-102) plane (r-plane), and the traveling direction of the superabrasive wire saw is within 5 degrees from parallel to the (11-20) plane (a-plane). It is to be.
A schematic diagram of the cutting method is shown in FIG. In this case, an axial direction (a-axis) orthogonal to (11-20) (a-plane) measured in advance by an orientation measuring device is measured, and the traveling direction of this axis and the superabrasive wire saw is perpendicular to each other. Is set. The superabrasive wire saw being perpendicular to the a-axis is preferably within 5 degrees from the direction in which the reference axis and the superabrasive wire saw are completely orthogonal, and more preferably within 2 degrees. Further, the cutting direction of the superabrasive wire saw is set parallel to the (1-102) plane (r-plane), and cutting is performed.
If the traveling direction of the superabrasive wire saw is set to an arbitrary direction with respect to the crystal plane, the following may be considered as reasons why the superabrasive wire saw cannot be cut parallel to the (1-102) plane (r-plane). For example, when any surface other than the (11-20) plane (a-plane) is cut so as to be a plane parallel to the traveling direction of the superabrasive wire saw, the (11-23) plane (n-plane) and (0001 ) Since the superabrasive wire saw is cut along the plane (c-plane), the cutting accuracy is considered to be lowered.

Also, the single crystal sapphire substrate cutting device according to the present invention is characterized by a superabrasive wire saw cutting device used for cutting a single crystal sapphire, the means for holding the single crystal sapphire, and (1 -102) means for setting the plane (r-plane) within 1 degree from parallel to the cutting direction of the superabrasive wire saw, and (11-20) (a-plane) of the single crystal sapphire And means for setting within 5 degrees from parallel to the traveling direction.
As the cutting device, for example, the cutting device shown in FIG. 3 can be used. This superabrasive wire saw cutting device is a device that can cut multiple workpieces at a time while pressing the superabrasive wire saw against the workpiece and reciprocating the superabrasive wire saw. In particular, it is most suitable when a highly efficient cutting process is required.
Also, for cutting a single crystal sapphire substrate with a superabrasive wire saw, it is appropriate to use a water-soluble processing liquid rather than a water-insoluble processing liquid because a higher cutting speed can be obtained. The reason why the cutting speed decreases when using a water-insoluble processing liquid is considered to be because the diamond abrasive grains slide on the surface of the workpiece (single crystal sapphire) due to the excellent lubricity of the water-insoluble processing liquid. .

A single crystal sapphire cutting experiment was conducted using a diamond wire saw in which diamond abrasive grains having an average abrasive grain size of 42 μm were fixed to a core wire made of a piano wire having a diameter of 0.18 mm with a resin bond. In the following cutting conditions, when the cutting direction of the superabrasive wire saw is parallel to the (1-102) plane and the traveling direction of the superabrasive wire saw is parallel to the (11-20) plane (invention), it is perpendicular to The effect of the present invention was confirmed by comparing cases (conventional examples).
(Cut condition)
Workpiece: Single crystal sapphire Workpiece size: φ50mm-L30mm
Super-abrasive wire saw cutting machine: made by Takatori
Main roller spacing: 570mm
Super-abrasive wire saw wire speed: 400 m / min
Superabrasive wire saw traveling direction: Reciprocating workpiece cutting speed: ave 0.1 mm / min
Tension of superabrasive wire saw: 35N
Processing liquid: A water-soluble processing liquid single crystal sapphire was cut into a substrate, and the waviness in the cutting direction of the substrate was measured. Three test pieces (nine in total) from the front side, center, and back side were used as samples. The test results are shown in Table 1.

As is clear from Table 1, it was found that the cutting accuracy is improved by making the traveling direction of the superabrasive wire saw parallel to the (11-20) plane (a-plane). The waviness of the cut surface is clearly large in the direction of 10 degrees with the a-plane. However, in the direction of 1 to 5 degrees, a difference from the parallel case was not recognized, and therefore it is considered that 5 degrees or less is preferable for cutting with high accuracy.

It is the schematic which shows the cutting method of a single crystal sapphire. It is the schematic which shows the crystal plane of a single crystal sapphire. It is the schematic which shows a superabrasive wire saw cutting device.

Explanation of symbols

1 Super Abrasive Wire Saw 2, 9 Reel 3, 4, 7, 8, Guide Roller 5, 6 Main Roller 10 Workpiece 11, 12 Nozzle

Claims (2)

A method for cutting a single crystal sapphire substrate having a (1-102) plane (r-plane) as a main surface by a superabrasive wire saw,
The cutting direction of the superabrasive wire saw is within 1 degree from parallel to the (1-102) plane (r-plane),
A method of cutting a single crystal sapphire substrate with a superabrasive wire saw, wherein the traveling direction of the superabrasive wire saw is within 5 degrees from parallel to the (11-20) plane (a-plane). A superabrasive wire saw cutting device used for cutting a single crystal sapphire substrate,
Means for holding the single crystal sapphire;
Means for setting the (1-102) plane (r-plane) of the single crystal sapphire within 1 degree from parallel to the cutting direction of the superabrasive wire saw;
A superabrasive wire saw cutting device comprising means for setting (11-20) (a-plane) of the single crystal sapphire within 5 degrees from parallel to the running direction of the superabrasive wire saw.

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