JPH03252132A - Detecting method of cutting resistance of slicer - Google Patents

Abstract

PURPOSE:To obtain a detecting method capable of accurately detecting cutting resistance so as to be able to reduce cutting resistance causing warpage of an inner circumferential blade by comparing the standard pattern of the change of power consumption, the number of revolution, etc., altering in response to the preset position of cutting and the pattern of the change of power consumption, the number of revolution, etc., at the current position of cutting. CONSTITUTION:In a slicer, in which an inner circumferential blade is held by a rotary disc and turned and driven and a material to be cut is sustained and moved to the inner circumferential blade side and sliced, a detecting means 21 for the power consumption of a motor 8 for driving the inner circumferential blade, a detecting means 22 for the number of revolution or rotational speed of the inner circumferential blade and a detecting means 23 for the location of cutting or speed of travel of the material to be cut are provided. When the fluctuation of cutting resistance is detected from the variation of power consumption and the number of revolution or rotational speed at the time of cutting, the standard pattern A of the change of power consumption and the number of revolution or rotational speed altering in response to the preset position of cutting and the pattern B or C or the like of the change of power consumption and the number of revolution or rotational speed at the current position of cutting are compared, thus detecting the state of the deformation of the inner circumferential blade together with the fluctuation of cutting resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cutting resistance detection method for a slicing device that can detect the dressing timing of an inner peripheral blade and can predict and detect deformation i of the inner peripheral blade, and reduces the consumption of an electric motor. When detecting fluctuations in cutting resistance from minute fluctuations in power, rotational speed of the inner peripheral blade, and the relationship between a pre-patterned cutting position and the measurement element, the current cutting situation can be grasped. The present invention relates to a method for detecting cutting resistance of an apparatus.

Conventional Technology As shown in Figure 1, a cutting machine is used to cut silicon wafers that are much thinner than silicon ingots, which are hard and brittle.
A slicing device is often used that cuts a wafer of a desired thickness from a silicon ingot (10) by attaching an inner peripheral blade (1) having a circumference of 2) to a rotating disk (3) and rotating it.

In a slicing machine, the inner peripheral blade deforms in the axial direction due to an increase in cutting resistance, causing warping and ridges in the cut silicon wafer, causing variations in thickness, and partially chipping the silicon wafer. Otherwise, cracks may occur.

This deterioration of the cut surface shape and wafer quality is caused by the warpage of the inner peripheral blade, and as a measure to suppress warpage due to increased cutting resistance of the internal peripheral blade, the change in the blade edge displacement over time is examined. Conventionally, methods such as performing dressing, controlling the cutting feed rate, and controlling the disk rotation speed have been implemented.

Dressing is a countermeasure that depends on the experience of the worker, and there are large variations, and it is particularly difficult to select the timing for dressing, and there are many cases where it is not done properly.

To indirectly measure the cutting resistance that occurs during cutting of the workpiece with the inner blade, an ammeter or wattmeter is installed on the electric motor that drives the rotation of the inner blade, and It is generally known that it is possible to measure the required value of time and detect the cutting resistance from this difference.

It is thought that the cutting resistance generated during cutting by the inner peripheral blade increases or decreases due to various factors, but of course the true cutting resistance cannot be measured using the indirect method mentioned above, and it is difficult to determine which factors cause the cutting resistance. I have no idea if it's increasing or not.

On the other hand, when the tension of the inner peripheral blade decreases, the alloy of the internal peripheral blade may come into contact with the material to be cut, which increases the cutting resistance and clearly determines the cause of defects such as warping. In order to do this, it is necessary to accurately understand the tension state of the inner peripheral blade, and furthermore, it is necessary to understand the cutting status of the inner peripheral blade.

In view of the problems of such a slicing device, an object of the present invention is to provide a detection method that can accurately detect cutting resistance so as to reduce the cutting resistance that causes the inner peripheral blade to warp. The object of the present invention is to provide a cutting resistance detection method that can detect cutting resistance and grasp the cutting situation.

Summary of the invention This invention monitors the cutting status of the inner peripheral blade of a slicing device.
As a result of various studies on the detection of cutting resistance with the aim of finding a way to understand it, we found that when detecting cutting resistance from minute fluctuations in the power consumption of the electric motor, the rotational speed of the inner peripheral blade, or the rotational speed,
By comparing the correlation with the measurement elements, which change depending on the cutting position of the material to be cut, with the patterned pattern in advance, it is possible to grasp the current cutting situation, detect the timing of dressing, and check the deformation state of the inner peripheral blade. The present invention was completed based on the finding that it is possible to predict and detect.

That is, the present invention provides a slicing device that holds and rotates an inner blade with a rotating disk, holds a material to be cut, and moves it toward the inner blade to slice it. A detection means for detecting the number of revolutions or rotational speed of the inner peripheral blade, and a means for detecting the cutting position or moving speed of the material to be cut are provided. When detecting resistance fluctuations, there is a standard pattern of power consumption and changes in rotational speed or rotational speed that change according to the preset cutting position, and a pattern of power consumption and changes in rotational speed or rotational speed at the current cutting position. A cutting resistance detection method for a slicing device is characterized in that the deformation state of the inner peripheral blade is detected as well as the variation in cutting resistance.

Structure of the Invention The present invention provides a slicing device including: 1. First, in order to prevent warping by detecting the cutting resistance that causes the inner peripheral blade to warp, the cutting resistance is detected from the power consumption of the electric motor as is well known, and also the rotational speed or rotational speed of the internal peripheral blade is detected. The cutting resistance can be detected even from minute fluctuations in .

The means for detecting the power consumption (VA) of the internal blade drive motor is as follows:
A known wattmeter may be used.

The means for detecting the rotational speed or rotational speed of the inner peripheral blade can detect the rotational speed using an optical encoder or the like, or can detect the rotational speed using a magnetic sensor, a linear sensor, or the like.

In addition, instead of the power consumption of the electric motor, the number of revolutions or the rotational speed of the inner peripheral blade, fluctuations in the rotational torque received by the inner peripheral blade drive system, for example, the shaft of a rotating disk, can be detected using a strain sensor, magnetostrictive sensor, etc. It is also good to detect the cutting resistance.

Next, changes in power consumption and rotational speed or rotational speed change depending on the cutting position of the material to be cut, so in order to accurately grasp the cutting condition, it is necessary to know the cutting position and pattern the changes. Detects the cutting position or moving speed of the material to be cut. The detection means is to detect the position of the material to be cut directly with an optical, magnetic, etc. sensor, or to detect the position of the material by installing an optical, magnetic, tracing, etc. sensor in the holding and moving system of the material to be cut. good.

Patterns of power consumption and changes in rotational speed or rotational speed that change depending on the cutting position.Firstly, a standard pattern of ideal cutting conditions, and furthermore, for example, if chips become clogged in the grindstone part of the inner peripheral blade, Change patterns under various conditions measured and set in advance, such as when the inner peripheral blade alloy is in contact with the material to be cut, etc., and the power consumption and rotation speed at the required cutting position during cutting. The deformed state of the inner peripheral blade can be detected by comparison with the pattern of changes in rotational speed.

In a slicing device, the tension state of the inner peripheral blade has a large effect on the control state such as warping of the inner peripheral blade. For example, if the tension of the internal peripheral blade decreases, the alloy of the internal peripheral blade may come into contact with the material to be cut. As a result, the power consumption of the electric motor for rotating the inner peripheral blade increases, but it is not only possible to judge that this is due to an increase in cutting resistance, but also to detect the deformed state of the inner peripheral blade by comparing the patterns described above. It is possible to accurately grasp the tension state and clearly determine the cause of defects such as warpage.

Based on the cutting force determined above, the deformation state of the inner peripheral blade, and the amount of displacement, for example, it is possible to determine the appropriate dressing time, or to send a control signal to a known internal blade warpage control device. The inner peripheral blade is controlled to maintain a stable condition.

Alternatively, as a warpage control device, electromagnets are placed on the front and back surfaces of the inner circumference so that electromagnetic force can be applied to the inner circumference blade,
When an imbalance of cutting resistance occurs, i.e.
If the detection signal of the displacement meter becomes larger than when there is no load, this detection signal is input to the logarithmic amplifier, and the output side is excited by passing current through the coil on the side where the distance between the inner peripheral blade and the electromagnet is larger. By doing so, it is possible to use a device configured to apply electromagnetic force to the inner peripheral blade to attract the inner peripheral blade and maintain cutting in a stable state.

As shown in FIG. 1, the slicing device according to the embodiment includes an inner peripheral blade (1) having a cutting blade grindstone (2) arranged around the inner peripheral edge of an annular metal disk having a required inner diameter, and a rotating disk (3). It consists of a structure that can be attached and rotated.

In addition, this slicing device cuts a wafer of a required thickness from a silicon ingot (10), which is a material to be cut.
The silicon ingot (10) is placed on the same base (4) that pivotally supports the rotating disk (3), and an indexer (6) placed on a feed table (5) that is horizontally movable at the required speed.
It is fixed and vertically suspended.

A silicon ingot (10) vertically fixed to an indexer (6) via an adhesive block (7) is moved in the vertical direction by an indexing motor.

Furthermore, as shown in Fig. 2, a motor wattmeter (21) is used to measure the power consumption of the three-phase motor (8) for driving the rotating disk (3), and the rotational speed of the inner peripheral blade (1) is measured. a blade tachometer (22) that detects the displacement of the cutting edge of the inner peripheral blade (1), a cutting position input device (23) using a copying method consisting of a cam and a resistor attached to the feed table (5), and a blade displacement meter that detects the displacement of the cutting edge of the inner peripheral blade (1). (24) is provided, and each detection signal is transmitted by a monitoring and control device (
20).

In such a slicing device, for example, when a 4-inch diameter silicon ingot is cut with an inner peripheral blade diameter of 21 inches,
The relationship between the length of the cutting arc and the cutting position is as shown in FIG. 3, and the relationship between the cutting resistance force and the amount of power fluctuation is usually directly proportional as shown in FIG. 4.

Therefore, the change in power consumption during cutting depending on the cutting position is:
Under normal conditions, the pattern is curve A shown in FIG.

For example, if chips clog the grindstone portion of the inner peripheral blade, cutting resistance increases, and power consumption increases, the pattern of curve B will be obtained.

When the cutting resistance of the inner blade increases due to clogging, the alloy of the inner blade bends and comes into contact with the material to be cut, which increases the power consumption of the electric motor for rotating the inner blade, and in this case, the curve C
This becomes the pattern. Furthermore, as the power consumption increases, the rotational speed of the inner peripheral blade may decrease.

In this way, by monitoring slight fluctuations in cutting resistance and slight fluctuations in the rotation speed of the inner peripheral blade, it is possible to accurately grasp the tension state of the inner peripheral blade and clearly determine the cause of defects such as warping. I can do it.

Furthermore, in addition to detecting slight fluctuations in the cutting resistance and the rotational speed of the inner peripheral blade, the difference between the cutting position detection signal of the cutting position input device (23) and the corrected value of the moving speed constant of the feed tenible (5) is calculated. It is possible to detect the true cutting resistance by inputting it into a dynamic amplifier, determine the appropriate timing for dressing, and output an alarm (25).

Effects of the Invention According to the present invention, the power consumption of the electric motor under various conditions measured and set in advance, the pattern of minute fluctuations in the rotational speed or the rotational speed of the inner peripheral blade, and the consumption at the required cutting position during cutting. By comparing the pattern of changes in power and rotational speed or rotational speed, it is possible to detect the deformation state of the inner peripheral blade, and also to determine the appropriate dressing time, and to use known internal blade warping control devices. It is possible to issue a control signal to control the inner peripheral cutter and maintain a stable state.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory diagram of the slicing apparatus, and FIG. 2 is a flowchart of the control system. FIG. 3 is a graph showing the relationship between the cutting position and the length of the cutting arc, and FIG. 4 is a graph showing the relationship between the amount of power fluctuation and cutting resistance force. FIG. 5 is a graph showing the relationship between cutting position and power consumption. DESCRIPTION OF SYMBOLS 1... Inner peripheral blade, 2... Cutting blade grindstone, 3... Rotating disk, 4... Base, 5... Feeding table, 6...
- Indexer, 7... Adhesive block, 8... 3-phase motor, 10... Silicon ingot, 2o... Supervisory control device, 21... Motor wattmeter, 22... Blade tachometer, 23... Cutting position input device, 24... Blade displacement meter, 25... Alarm.

Claims (1)

[Claims] 1. In a slicing device that holds and rotates an inner blade with a rotating disk, holds a material to be cut, and moves it toward the inner blade for slicing, the consumption of the electric motor for driving the inner blade is A means for detecting electric power, a means for detecting the rotational speed or the rotational speed of the inner peripheral blade, and a means for detecting the cutting position or moving speed of the material to be cut are provided, and the power consumption and rotational speed during cutting can be detected from fluctuations in the rotational speed or rotational speed. When detecting fluctuations in cutting resistance, a standard pattern of changes in power consumption and rotational speed or rotational speed that changes according to a preset cutting position, and a standard pattern of changes in power consumption and rotational speed or rotational speed at the current cutting position are used. A cutting resistance detection method for a slicing device, characterized in that a change in cutting resistance and a deformed state of an inner peripheral blade are detected by comparison with a pattern. 2. A cutting resistance detection method for a slicing device, characterized in that a detection means for detecting fluctuations in the rotational torque of a rotating disk is provided instead of or in addition to the power consumption detection means.