JPH08187724A - Blade deflection correcting mechanism for slicing machine and correcting method therefor - Google Patents

Abstract

PURPOSE: To more accurately regulate the deflecting amount of a blade by presuming the change of the deflecting amount of the blade in advance. CONSTITUTION: Axial load detecting means 17 detects an axial load which operates at least at either a work W or a blade 7. Deflecting amount calculating means 21 calculates the deflecting amount of a blade 7 based on the input signal from the means 17. Deflecting amount storage means 22 stores the input signal from the means 21. Deflection compensating means 23 presumes the change of the deflecting amount of the blade 7 on the way of cutting the work W from the apparent deflecting amount of the blade 7 to be detected before the cutting of the work W at the previous time is started and after the cutting is finished based on the signals from the means 21 and 22, presumes the change of the apparent deflecting amount of the blade 7 on the way of cutting this time from the apparent deflecting amount, and calculates the actual deflection of the blade 7 based on the apparent deflecting amount and the deflecting amount of the blade 7 to be detected during cutting of the work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade bending correction mechanism for a slicing device for detecting and correcting the bending generated in a blade when a thin piece is cut from a work such as a semiconductor ingot by an inner peripheral blade of the blade, and a correction method thereof. It is a thing.

[0002]

2. Description of the Related Art Conventionally, when cutting a thin piece from a work such as a semiconductor ingot, a slicing device has been used as follows. That is, one end of the work is exposed to the inside of a blade having a circular inner peripheral blade, and the work is relatively moved in the radial direction of the blade while rotating the blade to cut a thin piece from the work. In such a slicing device, since the processing accuracy is deteriorated when the blade is bent during cutting of the work, the bending amount of the blade is detected, and by adjusting the rotational speed of the blade, the cutting feed speed, or the like, I was able to cut with precision. In this case, the amount of bending of the blade is detected by a magnetic sensor or the like provided in the vicinity of the blade (Japanese Utility Model Laid-Open No. 62-70904, Japanese Patent Laid-Open No. 1-90904).
182015 gazette).

[0003]

However, in the above slicing device, when the sensor detects the amount of bending of the blade, if the sensor is arranged in a range in which the work moves with respect to the blade, the sensor interferes with the work, so that the mounting position Was restricted. For this reason, there has been a problem that the amount of bending of the blade cannot be accurately detected, and therefore the blade cannot be cut with a preferable accuracy.

In order to solve this problem, there has already been proposed a device in which the bending of the blade is detected through the thin piece to be cut (see Japanese Patent Laid-Open No. 4-138210).

However, although this device can avoid interference between the sensor and the work, it is not suitable for use in a work having a resistance value close to that of a conductor. Because if the work is always cut with the same thickness,
It is also possible to exclude only the component related to the intervening thin piece from the detection result by the sensor and to separately detect only the component related to the deflection of the blade, but in general, there is variation in the thickness of the thin piece to be cut, so it is high. This is because accurate detection cannot be expected.

Therefore, the present inventors have previously proposed Japanese Patent Application No. 5-2.
No. 48953 proposes a slicing device capable of estimating the bending amount of the blade from the change of the load acting in the axial direction of the blade and performing more accurate detection.

However, in this slicing device, the amount of bending of the blade is detected by converting the strain in the sensor into an electric signal, and the load acting on the sensor changes due to thermal displacement of the sensor mounting portion. Since an error occurs in the detection result of the sensor, noise corresponding to this error is generally added to the electric signal. Therefore, for example, as shown in FIG. 6A, a noise component (indicated by A in FIG. 6A) is added to the detected deflection amount and the actual deflection amount (in FIG. 6B) is added. , B) and a larger apparent deflection amount (indicated by C in FIG. 6A). Then, the magnitude of this noise changes depending on changes in temperature and operating conditions of the slicing device. As a result, there is a problem that the deflection of the blade cannot be properly corrected.

In view of this, the present application aims to provide a blade deflection amount correction mechanism for a slicing device and a correction method capable of more accurately detecting and correcting the blade deflection amount in consideration of the influence of noise in advance. And

[0009]

In order to achieve the above object, in the invention according to claim 1, one end of the work is exposed to the inside of the inner peripheral blade of the blade, and the work is rotated while the radius of the blade is rotated. In a slicing device that cuts a thin piece from a work by relatively moving in a direction, an axial load detection means for detecting an axial load acting on at least one of the work and the blade, and the axial load detection. A deflection amount calculation means for calculating the deflection amount of the blade based on an input signal from the means, a deflection amount storage means for storing the input signal from the deflection amount calculation means, the deflection amount calculation means and the deflection amount storage means Based on the input signal of, the blade's apparent deflection amount detected before and after the cutting of the previous work is changed Deflection compensating means for estimating the actual deflection of the blade based on the apparent deflection and the blade deflection detected during cutting of the workpiece And a bending correction means for correcting the bending amount of the blade based on the actual bending amount of the blade.

According to a second aspect of the present invention, the deflection compensating means is detected by the axial load detecting means before the cutting start of the previous work by the blade and after the cutting is finished, and is calculated by the deflection amount calculating means. Assuming that the apparent bending amount changes linearly during cutting, the actual bending amount of the blade is calculated by excluding it from the bending amount of the blade calculated during cutting of the work this time.

According to the third aspect of the invention, the axial load acting on at least one of the work and the blade is converted into an electric signal, and the deflection amount of the blade is calculated based on the electric signal. Predict the apparent deflection amount only during the cutting from the change in the electric signal generated before the cutting of the work and after the completion of the cutting, at the time of the next cutting, calculate the actual deflection amount of the blade by eliminating the influence of the deflection amount, The blade deflection is adjusted based on the actual deflection amount.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a slicing apparatus to which the present invention is applied, in which a headstock 2 is erected on a base 1. A main shaft 4 is rotatably supported by a main bearing 3 of the main stock 2, and the main shaft 4 is rotated by driving a main shaft drive motor 5. A tension disk 6 is fixed to the tip of the main shaft 4, and a blade 7 is attached to the peripheral edge of the tension disk 6. The blade 7 is made of a circular thin plate having an opening in the center, and an inner peripheral blade 8 made of diamond particles or the like is fixed to the inner peripheral edge thereof.

Further, two rows of guide rails 9 are provided on the base 1 so as to be orthogonal to the axial direction of the main shaft 4,
A slide table 10 is slidably mounted on both guide rails 9. A central portion of the slide table 10 is extended downward, and a first ball screw 11 is screwed therein. The first ball screw 11 is rotated by the drive of the cutting feed motor 12, and the slide table 10 is reciprocated along the guide rail 9.

A holding member 13 is mounted on the upper surface of the slide table 10 along a guide rail 10a so as to be slidable in the axial direction of the main shaft 4. The holding member 13 holds one end of the work W such as a semiconductor ingot, and the downwardly extending portion is screwed into the second ball screw 14.
The second ball screw 14 is rotated by the indexing motor 15,
The holding member 13 is adapted to reciprocate.

As described above, the work W is given a cutting feed by driving the cutting feed motor 12 to rotate the first ball screw 11 and moving the slide table 10 to the right side in FIG. Further, the work W is the indexing motor 1
By driving 5 to rotate the second ball screw 14 and move the holding member 13 leftward in FIG. 1, its tip is indexed inside the inner peripheral blade 8 of the blade 7, and the cutting position is Adjusted.

A dress grindstone 16 is provided on the upper surface of the slide table 10. This dress grindstone 1
6 can face the inside of the blade 7, and the inner peripheral blade 8 of the blade 7 can be dress-formed.

As shown in FIG. 3, the holding member 13 is provided with an axial load detection sensor 17. The axial load detection sensor 17 employs a so-called strain sensor that replaces the acting force with a strain amount and further converts the strain amount into an electric signal. Then, a positive signal is output when a compressive load acts on the axial load detection sensor 17, and a negative signal is output when a tensile load acts. As a result, the load acting in the axial direction of the work W when the work W is cut by the blade 7 is detected. The detected load is input to the control unit 18, and is converted into the bending amount of the blade 7 as described below.

As shown in FIG. 3, the control section 18 comprises a first control section 19 and a second control section (deflection amount adjusting means) 20. The first control unit 19 includes a bending amount calculation device 21, a bending amount storage device 22, and a bending compensation device 23.

The deflection amount calculation device 21 calculates the deflection amount of the blade 7 based on the electric signal input from the axial load detection sensor 17. Therefore, the following mathematical formula is stored in the deflection amount calculation device 21.

Here, the calculation method is shown in FIG.
This will be described with reference to (b). First, the balance of the axial component of the work W of the illustrated load will be considered. Blade 7 is Z
It is not bent in the axial direction, and the work W is on the Z ₁ axis and Y
When not tilted in the axial direction, the balance equation is as follows.

[0022]

[Equation 1]

When the blade 7 bends in the Z-axis direction and the load Fz in this direction acts on the work W, the balance equation is as follows in consideration of the gravity Fy acting on the work W.

[0024]

[Equation 2]

Therefore, the load acting on the work W in the Z-axis direction is given by the following equation.

[0026]

(Equation 3)

According to (Equation 3), in consideration of the case where the axial direction of the work W is inclined with respect to the axial direction of the blade 7 and the case where the cutting force or gravity acts on the work W by the blade 7. The corrected axial load Fz of the blade can be accurately calculated.

The balance equation in the direction orthogonal to the axial direction of the workpiece is as follows.

[0029]

[Equation 4]

When these equations are modified and substituted for (Equation 3) with sin ² θ ₁ ≈0, the following equation equivalent to (Equation 3) can be obtained.

[0031]

(Equation 5)

Based on such an equation, each load can be detected only by the Kistler dynamometer, the amount of bending of the blade 7 can be accurately calculated, and the cutting control thereafter can be accurately performed.

When the size and weight of the work W in the axial direction are relatively small, that is, when the load Fy in the Y-axis direction is sufficiently small, or when the work W is attached, the value detected by the axial load detection sensor 17 is set to 0. -F to reset
The term of yk sin θ ₂ can be omitted.

Further, the cutting force Fx is detected from the cutting power, specifically, the amount of increase in the power of the cutting feed motor 5 at the start of cutting, and directly substituted into (Equation 1), the load is detected by the axial load detection sensor 17. It is possible to correct the bending amount of the blade 7 related to the cutting force without detecting Fxk.

The deflection amount storage device 22 stores the result calculated by the deflection amount calculation device 21 based on the electric signal input from the axial load detection sensor 17.

The bending compensator 23 is a bending amount calculator 21.
And an input signal from the deflection amount storage device 22,
The control signal is output to the second controller 20. That is, the bending amount of the blade 7 before and after the cutting of the work W stored in the bending amount storage device 22 at the time of the previous cutting, and the bending amount of the blade 7 at the present time detected by the bending amount calculation device 21. Based on the above, a control signal is output to the second controller 20 so that the blade 7 is not bent.

More specifically, according to the input signal from the deflection amount storage device 22, the apparent deflection amounts S ₁ , S _{2 of the} blade 7 detected before and after the cutting of the work W are calculated at the next cutting according to the following equation. The change in the apparent deflection amount δ ₁ of the blade 7 is estimated.

[0038]

(Equation 6)

The load acting in the axial direction during the cutting of the workpiece W is converted into an electric signal by converting the strain in the axial load detecting sensor 17 into the electric signal as described in the section of [Problems to be Solved by the Invention]. Since noise is added to this electric signal during detection by the above-mentioned detection, the noise component is removed according to the following equation based on the result calculated by the above equation in the present embodiment, so that the actual deflection of the blade 7 during cutting is performed. The quantity δ is calculated accurately.

[0040]

(Equation 7)

On the other hand, in the second control section 20, a control signal based on the actual deflection amount δ of the blade 7 calculated by the deflection compensating device 23 is input to the rotation speed calculating device 24 and the dress timing determining device 25, respectively, to drive the spindle. The spindle drive motor 5 and the cutting feed motor 12 are passed through the motor control device 26, the cutting feed motor control device 27, and the dress control device 28.
Drive control. In addition, the pulse signal generated from the cutting feed motor 12 is the cutting status detection device 2
By inputting into 9, the cutting feed speed and the relative position of the blade 7 and the work W are detected.

The rotation speed calculation device 24 drives and controls the spindle drive motor 5 via a spindle drive motor control device 26. Specifically, the target rotation speed Na is calculated so that the amount of bending of the blade 7 is zero. The calculation of the target rotation speed Na is performed based on the preset correlation between the rotation speed and the bending amount of the blade 7.

The spindle drive motor control device 26 drives and controls the spindle drive motor 5 according to the target rotation speed Na or the previously stored basic rotation speed N _{0 in} accordance with the control signal from the deflection compensating device 23.

The cutting condition detecting device 29 receives the pulse signal output from the cutting feed motor 12, and the cutting feed position of the work W from the cutting start position to the cutting end position of only the work W not including the slice base 30 described below. It is determined whether or not it is within the range L up to. When it is determined that the value is within the range L, the rotation amount calculation device 24 and the dress timing determination device 25 are output via the deflection amount calculation device 21 or the deflection compensation device 23, respectively, and the spindle drive motor 5,
The cutting feed motor 12 and the like are drive-controlled. Further, when it is determined that it is outside the range L, only the cutting feed motor 12 is drive-controlled.

Further, the dress timing determination device 25 is
Based on the input signal from the deflection compensating device 23, it is determined whether or not it is time to perform dressing, and drive control is performed on the members related to dressing, such as the spindle drive motor 5 and the cutting feed motor 12. .

The side edge of the work W, that is,
A slice base 30 made of carbon or the like is fixed to a portion of the blade 7 that is finally cut by the inner peripheral blade 8. The slice base 30 prevents the cutting resistance acting on the blade 7 from being suddenly released at the end of the cutting of the work W and damaging the work W at the final cutting portion.

Next, the cutting control of the slicing device having the above construction will be described with reference to the flowchart of FIG.

First, in step S1, the spindle drive motor 5 is driven so that the rotation speed of the blade 7 becomes the reference rotation speed N ₀ . Then, in step S2, the index feed motor 15 is driven to rotate the second ball screw 14, thereby advancing the work W to the left side in FIG. As a result, one end of the work W is inserted from the front surface 7 a side of the blade 7 to the inside of the blade 7, and is projected and indexed by a minute amount toward the back surface 7 b side of the blade 7. Then, in step S3, the cutting feed motor 12 is driven to rotate the first ball screw 11, and the work W is moved to the right side in FIG.

Next, in step S4, the cutting feed position is detected, and in step S5, the deflection amount S ₁ of the blade 7 before the start of cutting, which is detected by the axial load detection sensor 17, is detected. After the bending amount S ₁ of the blade 7 detected in S5 is stored, it is determined in step S7 whether cutting has started. If the cutting has not been started, steps S3 to S6 are repeated, and if the cutting has been started, the process proceeds to step S8 to detect the deflection amount S of the blade 7. At the time of the first disconnection, the detection value correction in step S10 is not performed, and the process proceeds to step S11.

In step S11, the deflection amount of the blade 7 detected by the axial load detection sensor 17 and the deflection amount S ₁ of the blade before the start of cutting stored in step S6 are stored.
It is determined whether or not the bending amount δ ₂ due to cutting, which is the difference between the above and the above, is larger than a predetermined value X. If the deflection amount δ ₂ due to cutting is larger than the predetermined value X, the blade 7 is moved in step S12.
The rotational speed of is controlled to reach the target rotational speed Na.

On the other hand, if it is determined in step S11 that the bending amount δ ₂ due to cutting is less than or equal to the predetermined value X, step S
At 13, the rotation speed of the blade 7 is kept at the reference value N ₀ .

Then, in step S14, it is determined whether the inner peripheral blade 8 of the blade 7 needs to be dressed. Specifically, the absolute value of the bending amount δ ₂ due to the cutting of the blade 7 is
It is determined that dressing is necessary only when the corresponding critical value R is exceeded, and dressing is performed in step S15.
If it is determined that the dress is unnecessary, step S1
Go to 6.

In step S16, it is determined whether or not the cutting of the work W is completed. If the cutting has not been completed, steps S8 to S15 are repeated. This makes it possible to control the rotational speed of the blade 7 so that the amount of bending due to the cutting of the blade 7 detected during the cutting of the work W becomes zero. If the cutting of the work W is completed, it is determined in step S17 whether or not the cutting work is completed. If it is determined that the cutting work is completed, the cutting control is ended, and if it is determined that the cutting work is not completed, the process proceeds to step S18.

In step S18, the deflection amount S ₂ of the blade 7 after the cutting of the work is detected, and in step S19, the deflection amount S ₂ of the blade 7 detected in step S18 is stored.

After that, the work W is indexed and moved in step S20, and the process returns to step S3 to set the work W 2 as described above.
Make the second disconnection. At the time of the second cutting, the same cutting control as at the time of the first cutting is performed from step S3 to step S8, but at the time of the second and subsequent cutting, the detection value is corrected at step S10. That is, the bending amount S of the blade 7 before cutting stored in step S6 during the previous cutting
_{From 1} and the bending amount S ₂ of the blade 7 after cutting, which is stored in step S19, the actual bending amount δ is calculated by the above-mentioned (Equation 6) and (Equation 7). Then, in step S11, the actual deflection amount δ obtained in step S10 is compared with X to determine whether or not the rotation speed control is necessary.

As described above, according to the above-described embodiment, by detecting the bending amount of the blade 7 before the start of cutting the work W and after the end of the cutting, the fluctuation due to the influence of noise occurring between the two detection values is estimated. However, since the rotational speed of the blade 7 is controlled so as to remove the influence of this noise from the next cutting, the amount of deflection of the blade 7 can be detected based on the change in the axial load. The error can be suppressed, and the work W can be appropriately cut.

In the above-described embodiment, the work W is cut by moving the work W with respect to the inner peripheral blade 8 of the blade 7, but the headstock 2 may be moved. In this case, in order to move the headstock 2, a structure similar to that of the slide table 10 can be adopted.

Further, in the above embodiment, the load acting in the axial direction of the work W due to the deflection of the blade 7 is detected by the axial load detecting sensor 17, but the load acting in the axial direction of the blade 7 itself is detected. You may make it detect.

Further, in the above-mentioned embodiment, the bending of the blade 7 is removed by adjusting the rotation speed of the blade 7.
It may be performed by moving in the axial direction.

In the above embodiment, the case where the detected value is corrected only at the second and subsequent cuttings has been described.
Only in the _first cutting, after the bending amount S ₁ of the blade 7 before the start of cutting is stored in step S6, the cutting feed is stopped, the bending amount of the blade 7 after a predetermined time is detected, and the bending amount is S It is also possible to store the value as ₂ , to restart the cutting feed, and to correct the detected value in step S10 similarly to the second time and thereafter.

Further, in the above-mentioned embodiment, an example in which the work W is cut flatly has been described, but the same correction is carried out when the work W is cut into a preset curvilinear balance to remove the influence of noise. be able to.

[0062]

As is apparent from the above description, according to the present invention, not only is the deflection of the blade generated when cutting the work detected based on the load acting in the axial direction, Since the bending that occurs during cutting is predicted and the cutting conditions are changed in advance so that such bending does not occur, the work can be cut with high accuracy.

[Brief description of drawings]

FIG. 1 is a front view of a slicing device according to an embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a block diagram of a control unit that controls cutting of the slicing device shown in FIG.

FIG. 4 is a flowchart showing a control method in the control unit shown in FIG.

5A and 5B show a load acting on a work, where FIG. 5A is a plan view and FIG. 5B is a front view.

FIG. 6 is a graph showing the relationship between the cutting time and the bending amount of the blade.

[Explanation of symbols]

 7 Blades 17 Axial Load Detection Sensor (Axial Load Detection Means) 21 Bending Amount Calculator (Bending Amount Computing Means) 22 Bending Amount Storage Device (Bending Amount Storage Means) 23 Bending Compensation Device (Bending Compensation Means) W Work

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Youji Hotta 5-3-3, Ujinahigashi, Minami-ku, Hiroshima City, Hiroshima Prefecture Toyo Advanced Technologies Co., Ltd.

Claims (3)

[Claims] 1. A slicing device in which a thin piece is cut out from a work by exposing one end of the work to the inside of an inner peripheral blade of the blade and relatively moving the work in the radial direction of the blade while rotating the blade. An axial load detecting means for detecting an axial load acting on at least one of the work and the blade, and a flexure amount calculating means for calculating the flexure amount of the blade based on an input signal from the axial load detecting means. And a bending amount storage means for storing an input signal from the bending amount calculation means, and detection based on the input signals from the bending amount calculation means and the bending amount storage means before the cutting start of the previous work and after the cutting end. The change in the apparent deflection of the blade during cutting is estimated from the apparent deflection of the blade, Deflection compensating means for calculating the actual deflection amount of the blade based on the deflection amount of the blade taken out, and deflection correcting means for correcting the deflection amount of the blade based on the actual deflection amount of the blade obtained by the deflection compensating means, A blade deflection correcting mechanism of a slicing device, which is provided with. 2. The deflection compensating means cuts the apparent deflection amount of the blade, which is detected by the axial load detecting means before the cutting start of the previous work by the blade and after the cutting is finished, and calculated by the deflection amount calculating means. Claim that the actual deflection amount of the blade is calculated by excluding it from the deflection amount of the blade calculated during the cutting of the workpiece this time, assuming that it changes linearly on the way. A blade deflection correcting mechanism of the slicing device according to 1. 3. An axial load acting on at least one of a work and a blade is converted into an electric signal, the amount of bending of the blade is calculated based on the electric signal, and before the cutting of the work by the blade is started. Predicting the amount of bending that is apparent during cutting from the change in electrical signal that occurs after the end of cutting, the actual amount of bending of the blade is calculated by eliminating the influence of the amount of bending when cutting next time, and based on the actual amount of bending. A blade bending correction method for a slicing device, characterized in that the bending of the blade is adjusted.