JPS61114813A - Cutting method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Field of application of the invention] This article relates to a method for reducing man-hours.

[Background of the invention]

Conventionally, a method of cutting a hard and brittle material such as a silicon single crystal into wafers is shown in FIG.

The workpiece 4 is rotated while the inner peripheral diamond blade 1 is rotated.
A method of cutting by cutting is used.

In this method, the tension of the inner peripheral diamond blade 1, the unevenness of the material of the blade 2, the roundness error of the inner peripheral blade part 3, the eccentricity between the center of the inner peripheral blade part 3 and the center of rotation, the inner peripheral diamond blade Warpage occurs in the cut wafer due to non-uniform sharpness of the portion 3, large changes in cutting resistance during cutting, and the like.

For this reason, the cut wafer is generally subjected to finishing processing in post-processes such as lapping and grinding, but in lapping, as shown in FIG.
As a result, the warpage of the wafer 7 is processed in a state in which the warpage is corrected by pressure, so when the processing pressure is released after processing, the warp is restored to its original state and is not improved.

Furthermore, in grinding, as shown in Fig. 6, the wafer 7 is generally processed by suctioning it to a vacuum chuck 8, but the wafer 7 is processed after its warpage is corrected by the suction force. Therefore, the warpage cannot be improved by repairing it after processing.

As described above, it is extremely difficult to correct the warpage that occurs during the cutting process in a subsequent process, which has the disadvantage of impairing the final accuracy of the wafer.

[Purpose of the invention]

An object of the present invention is to provide a cutting method that eliminates the above-mentioned drawbacks of cutting and causes less warpage.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that the end face of the material to be cut is flattened in a rigid state before cutting, and then the cutting process is performed using an inner peripheral diamond blade. .

[Embodiments of the invention]

The present invention will be explained below with reference to FIG.

In FIG. 1, 4 is a workpiece to be processed into a wafer, 1 is an inner peripheral diamond blade, 9 is a chuck body that holds the inner peripheral diamond blade 1, and 10 is a cup-shaped diamond grindstone.

In the above configuration, first, the cup-shaped diamond grinding wheel lO
is rotated to the right of the figure and sent downward.

The end face 11 of the workpiece 4 is ground. Next, the inner peripheral diamond blade 1 is sent downward in the figure while rotating.
A portion of the workpiece 4 is cut into wafers 7.

By processing in this way, the cut surface of one side of the wafer 7 by the inner peripheral diamond blade 1 can be cut using a cup-shaped diamond grinding wheel with high force and high rigidity, even if there is a flatness error as in the conventional technology. -10, so it is processed into a highly accurate flat surface.

As described above, according to the present invention, the cup-shaped diamond grindstone 10 forms a highly accurate surface that can serve as a processing reference in the subsequent process.

As shown in Figure 3, by lapping and grinding,
With this reference surface, other surfaces are corrected, and a highly accurate wafer without warpage can be obtained.

In the above embodiment, the cup-shaped diamond grinding wheel 10 and the inner diamond blade 1 were moved separately, but the cup-shaped diamond grinding wheel 10 was moved slightly ahead of the inner diamond blade 1 and both were moved at the same time. Good too. At this time, the workpiece 4 may be moved and processed.

Further, in the above embodiment, the work material 4 was machined while being stopped, but the work material 5 may be machined while rotating.

〔Effect of the invention〕

As described above, according to the present invention, since one surface of the wafer becomes a highly accurate reference surface, the flatness error on the other surface can be corrected in the subsequent process, and a highly accurate wafer with less warpage can be obtained. There is.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the cutting method according to the present invention, FIG.
FIG. 3 is a schematic diagram showing the finishing process of a wafer cut by the present invention, FIG. 4 is a schematic diagram showing the cutting method by the conventional technique, and FIGS. 5 and 6 are the finishing steps of the wafer cut by the conventional technique. It is a schematic diagram showing a process.

Claims (1)

[Claims] In a method of cutting work materials such as hard and brittle materials using an inner peripheral diamond blade, the end face of the work material is ground flat, and then the work material is cut into thin pieces using an internal peripheral diamond blade. A cutting method characterized by: