JPH02134212A - Cutting method - Google Patents

Abstract

PURPOSE:To prevent the displacement of an inner peripheral edge thereby to improve the accuracy in warp, thickness and parallelism of a thin plate by providing one or more displacement sensors in the vicinity where the inner peripheral edge cuts so a to detect the displacement of the inner peripheral edge, and controlling the speed of a relative movement of a supporting bed in a centrifugal direction of the inner peripheral edge on the basis of a signal from the sensors. CONSTITUTION:When cutting of a plate 4 is started, the displacement of an inner peripheral edge 2 is detected by a displacement sensor 6. A signal output from the sensor 6 is latched into a control unit 8. The control unit 8 obtains the displacement of the inner peripheral edge 2, operating and outputting a cutting speed controlling signal to a feeding speed controlling unit 9. The cutting speed is changed faster or slower in accordance with the displacement of the inner peripheral edge 2. On the basis of the input controlling signal, the feeding speed controlling unit 9 drives a controlling valve 10 which controls the flow rate of pressurizing oil running in a driving cylinder 11. Accordingly, the cutting and feeding speed of the plate 4 by a feed supporting bed 3 is changed. Meanwhile, an air nozzle 7 is always driven during cutting, taking the air into a gap 4a so as to blow away entering water drops. Thus, the deformation of the inner peripheral edge 2 due to the interference between a thin plate 41 and the edge 2 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for cutting a hard and brittle material, such as a silicon ingot, which is formed into an annular shape. This invention relates to a method of cutting by rotating an inner peripheral blade having a blade on its periphery at high speed and moving the inner peripheral blade of a cutting feed support in a centrifugal direction.

[Prior art]

When cutting silicon wafers from silicon ingots, a cutting device is used that rotates an extremely thin circular ring-shaped inner peripheral blade at high speed.

FIG. 13 shows the schematic structure of the cutting device, in which an annular inner peripheral blade 51 is provided horizontally on the cutting device main body 50, and the inner peripheral blade 51 rotates at high speed. . A workpiece holder 52 that can be moved independently in the axial direction and radial direction of the inner peripheral blade 51 is provided on the inner peripheral side of the inner peripheral blade 51. This workpiece holder 52 supports a workpiece 53 such as a cylindrical silicon ingot with its axial direction being vertical.

When the inner peripheral blade 51 is rotated at high speed and the workpiece 53 is moved outward in the centrifugal direction of the inner peripheral blade 51 as shown by the broken line, the workpiece 53 comes into contact with the inner peripheral edge of the inner peripheral blade 51. The cutting will begin. Cutting fluid is continuously supplied to this cutting position from cutting fluid nozzles 54 and 54 disposed on both sides of the material to be cut 53, and the material to be cut 53 is cut.

By the way, when cutting a silicon ingot,
Since silicon is fragile and expensive, the thickness of the inner circumferential blade 51 is made extremely thin in order to eliminate waste due to cutting allowance as much as possible. Therefore, when a hard and brittle silicon ingot is cut, the inner circumferential blade 51 is displaced in its axial direction, which may impair the parallelism of both surfaces of the cut thin silicon wafer.

Therefore, in order to prevent cutting when the inner peripheral blade 51 is displaced, a non-contact displacement meter 55 that detects the displacement of the inner peripheral blade 51 is provided near the workpiece 53, and the inner peripheral blade 51 is Blade 5
1, and if the magnitude of displacement during cutting exceeds a preset limit value, a notification is given and the workpiece 53 is cut.
The cutting operation is stopped.

In addition, in order to prevent such displacement of the inner circumferential cutter,
No. 8-101082 proposes a method of supplying fluid at a constant pressure to the inner peripheral blade. However, when cutting with this method, unnecessary fluid is supplied to the space between the material to be cut and the inner blade, and the thin plate being cut and the inner blade, resulting in an increase in the displacement of the inner blade. This causes problems such as the thin plate cracking and scattering, so it is not put into practical use.

(Problems to be Solved by the Invention) As described above, when the displacement of the inner peripheral blade 51 exceeds the limit value and the cutting operation stops during cutting of the material to be cut 53, the operator must dress the inner peripheral blade 51 or After stopping the rotation of the inner circumferential blade 51 and performing work such as re-stretching to change the attachment state of the inner circumferential blade 51 or replacing the inner circumferential blade 51, the material to be cut 53 is
After confirming that the displacement of the inner peripheral blade 51 is within the limit value, the cutting operation is restarted. Such a cutting device has the trouble of having to temporarily interrupt the cutting operation.

On the other hand, the operator needs to determine the cause of the displacement from the output of the displacement meter 55 and correct the displacement of the inner peripheral cutter 51, so there is a problem in that the operator requires skill. For this reason, productivity is low when cutting thin plates from hard and brittle materials to be cut.
Further, there are problems such as a poor yield of the cut thin plates and an increase in the manufacturing cost of the cut thin plates.

The present invention has been made in view of the above problems, and includes:
A cutting method that prevents displacement of the inner circumferential blade during cutting and improves the warpage, thickness, and parallelism accuracy of a thin plate when cutting a thin plate from a material to be cut, thereby improving yield and productivity. The main purpose is to provide.

[Means to solve the problem]

In order to achieve the above object, the present invention has an annular shape and rotates an inner circumferential cutter provided on the inner circumferential edge thereof.
In the cutting method, the workpiece is cut by bringing the workpiece supported on the cutting feed support stand into contact with the inner peripheral blade by relative movement of the cutting feed support stand or the inner peripheral blade in the inner peripheral blade centrifugal direction. , a displacement sensor for detecting displacement of the blade is provided at one or more force points near the cutting point of the inner peripheral blade, and based on a signal from the displacement sensor, relative movement of the inner peripheral blade of the cutting feed support base in a centrifugal direction is provided. Control speed.

Furthermore, the present invention is characterized in that the rotation speed of the inner peripheral blade is controlled instead of controlling the relative movement speed.

Furthermore, 0.2 to 2 kg/c between the material to be cut and the inner peripheral blade
The present invention is characterized in that a nozzle for blowing gas at a pressure of rA is provided, and the blowing pressure of the gas from the nozzle is controlled based on a signal from the change sensor.

[Effect]

The displacement sensor detects the displacement of the inner circumferential blade in the vicinity of the cutting location, the displacement sensor transmits this detection signal to the control section, and the control section controls the relative cutting feed support base based on the signal. The moving speed of the inner circumferential cutter in the centrifugal direction, the rotational speed of the inner circumferential cutter, or the blowing pressure are controlled, the displacement of the inner circumferential cutter is corrected, and the parallelism of the inner circumferential cutter is maintained.

〔Example〕

The present invention will be described in detail below with reference to drawings showing embodiments thereof.

FIG. 1 is a schematic perspective view of a cutting device according to the present invention,
An annular inner peripheral blade holder 1 is rotatably attached in a horizontal position to a cutting device main body (not shown).

On the inner circumferential side of this inner circumferential blade holder l, an annular inner circumferential blade 2 whose outer circumferential side is held between the inner circumferential holder l is stretched and disposed. The inner peripheral blade 2 is composed of an inner peripheral blade body 2a made of an annular stainless steel thin plate and a blade member 2b made of a diamond blade provided along the inner peripheral edge thereof. A cutting feed support 3 is disposed on the inner circumferential side of the inner peripheral blade 2, and the material to be cut 4, such as a cylindrical silicon ingot, is mounted on this with its axis in a horizontal state. It has become. In other words, so that the material to be cut 4 is cut by the inner peripheral blade 2 at right angles to its length,
The inner peripheral blade 2 and the workpiece 4 can be positioned. This cutting feed support stand 3 is movable independently in the centrifugal direction and axial direction of the inner peripheral blade 2.

By these movements, the material to be cut 4 is moved in the direction of the outlined arrow and cut, and by moving in the axial direction of the inner peripheral blade 2, the thickness of the thin plate to be cut can be set. A cutting fluid nozzle 5 that sprays cutting fluid is disposed on one or both sides of the inner peripheral blade 2 of the cutting feed support base 3 in the circumferential direction at a position where the inner peripheral blade 2 and the workpiece 4 come into contact. has been done. The inner peripheral blade 2 is located near the cutting point on the upper surface side of the inner peripheral blade 2.
A displacement sensor 6 is provided to detect displacement in the vicinity of the cutting point.

Even if the movement of the cutting feed support 3 in the centrifugal direction coincides with the radial direction of the inner peripheral blade 2, it rotates around the base end of a horizontal arm (not shown) that supports the cutting feed support 3. The cutter 4 may be moved in a substantially radial direction to draw a large-diameter arc.Also, the workpiece 4 may be fixed and the inner peripheral blade 2 may be moved in a centrifugal direction.

As shown in FIGS. 2 and 3, a gap 4a between the cut portion of the workpiece 4 and the blade member 28 portion of the inner peripheral blade 2 is located near the cutting location on the lower surface side of the inner peripheral blade 2. Approximately 0.2~
An air nozzle 7 is provided that blows air at a pressure of 2 kg/cm''.

Further, the displacement sensor 6 is connected to a control section 8, which will be described later, to send the displacement of the inner peripheral blade 2 as a signal.
is connected to a feed speed control section 9 that controls the amount of movement of the cutting feed support 3, and further, the feed speed control section 9 controls the amount of movement of the rod of the drive cylinder 11 that moves the cutting feed support 3. The pressure oil flow control valve lO is connected to the sticky wire.

Note that a hydraulic servo valve may be used instead of the pressure oil flow control valve 10. Further, the inner peripheral blade holder 1 is rotated by the rotational drive of the drive motor 12 by a belt 13 that is passed between the pulley 1a of the holder 1 and the boot 2a of the drive motor 12. The inner peripheral blade holder 1 is provided with a rotation detector 15, which emits a pulse signal when the inner peripheral blade 2 held by the inner peripheral holder 1 makes one rotation, which is sent to the control section 8. It is ready to be sent.

Thus, with the above configuration, by driving the drive cylinder 11, the cutting feed support base 3 is moved in the centrifugal direction of the inner peripheral blade 2 with the workpiece 4 attached thereto, and The inner peripheral blade holder l is rotated by the rotational drive of the drive motor 12, and the inner peripheral blade 2 is rotated integrally with the inner peripheral blade holder l, so that the workpiece 4 attached to the cutting feed support stand 3 is rotated in the inner peripheral blade holder l. A thin plate is cut by the blade member 2b of the peripheral blade 2, and if displacement occurs in the inner peripheral blade 2 during this cutting, the displacement of the internal peripheral blade 2 is corrected as described below.

That is, as shown in the flowchart of FIG. 4, when cutting of the material to be cut 4 is started, the displacement of the inner peripheral blade 2 is detected by the displacement sensor 6, and its output signal is sent to the controller 8.
be taken into account. This control section 8, as shown in FIG.
The amount of displacement of the inner peripheral blade 2 is determined by averaging the data acquired for each one-rotation pulse signal a of the inner peripheral blade 2 sent from the rotation detector 15, and the speed changes to a slower speed depending on the magnitude of this displacement amount. The feed speed control section 9 calculates a cutting speed control signal to
Output to. Then, the feed speed control section 9 operates a pressure oil flow control valve 10 to control the oil flow rate flowing into the drive cylinder 11 to control the feed speed based on the input control signal. The cutting feed rate of the material to be cut 4 by the support base 3 is changed.

On the other hand, the air nozzle 7 is always operated during the cutting operation of the material 4 to be cut into a thin plate (wafer) 41 to blow air into the gap 4a and blow away water droplets that have entered the gap 4a. This prevents deformation of the inner peripheral blade 2 due to interference between the inner peripheral blade 2 and the inner peripheral blade 2.

As a result, as shown in the graph of FIG. 6, when the present invention is applied, the amount of displacement of the inner peripheral cutter 2 is reduced as shown on the right side of the figure, compared to the amount of displacement of the inner peripheral cutter 2 when the present invention is not applied, which is shown on the left side of the figure. The amount of displacement becomes extremely small. In addition, C in the same figure
D shows a displacement curve of the inner circumferential cutter 2 when the present invention is not applied, and D shows a displacement curve of the inner circumferential cutter 2 when the present invention is applied.

Therefore, as described above, when the present invention is applied, it is possible to prevent the displacement (warpage) of the inner peripheral blade 2 that occurs during cutting of the material 4 to be cut, and to reduce the warpage, thickness, and thickness of the cut thin plate 41. Parallelism accuracy can be improved and yield can be improved. Furthermore, since the frequency of operator intervention in dressing, retention, etc. is reduced, the operating rate can be improved and variations in work can be reduced. Furthermore, since the frequency of dressing is reduced, the life of the inner peripheral cutter 2 can be extended.

FIG. 7 is an explanatory diagram of another embodiment of the present invention. In this embodiment, a servo motor 21 is used in place of the pressure oil flow control valve 10 in the above embodiment, and the drive cylinder 11 Instead, a drive feed screw 22 is used, the drive feed screw 22 is rotated by the rotational drive of a servo motor 21, and the cutting feed support base 3 is moved by the rotation of the drive feed screw 22. Then, the displacement sensor 6 sends a signal indicating the amount of displacement of the inner peripheral blade 2 to the control section 8, and the control section 8 sends a control signal to the feed speed control section 9, which controls the feed speed control section. 9 controls the rotation speed of the servo motor 21, thereby changing the rotation speed of the drive feed screw 22 to control the inner peripheral blade 2 during cutting.
control to reduce the displacement of

FIG. 8 is an explanatory diagram of still another embodiment of the present invention,
In this embodiment, as in the embodiment shown in FIG. A motor rotation control section 31 is connected, an inverter 32 is connected to the drive motor rotation control section 31, and the drive motor rotation control section 31 is controlled by a control signal from the control section 8, and based on this control. The inverter 32 is controlled to change the rotational speed of the drive motor 12, thereby controlling the amount of displacement of the inner peripheral blade 2 to be small.

In this embodiment, the moving speed of the cutting feed support 3 is controlled, but the rotation speed of the motor 12 may also be controlled in accordance with the warpage detected by a displacement sensor.

Figures 9 and 10 are graphs showing the effect of controlling the rotational speed of the motor 12 or the inner blade 20, and Figure 9 shows the case where the inner blade is displaced (positive) toward the material to be cut (ingot). , and Figure 10 shows examples of displacement (negative) toward the cut piece (wafer) side. The left side of each figure shows the inner peripheral blade rotation speed and displacement when there is no control, and the right side shows the case when there is control. It shows the relationship with quantity.

In either case, the displacement is significantly reduced by applying the present invention.

In the present invention, the amount of displacement can also be suppressed by deflecting the blowing pressure from the air nozzle according to the amount of displacement detected by the inner peripheral blade. Figure 11.12 shows the relationship between the displacement amount of the inner peripheral blade and the blowing pressure in this example.
It is shown in the same manner as Figure 10. In this case as well, the displacement is significantly reduced by applying the present invention.

〔Effect of the invention〕

The cutting method according to the present invention has the above configuration,
Therefore, the displacement of the inner peripheral blade is detected by a displacement sensor, and based on the signal from the displacement sensor, the controller controls the relative movement speed of the cutting feed support and the inner peripheral blade or the inner peripheral blade. By controlling the rotation speed or blowing pressure, displacement of the inner circumferential blade during cutting can be prevented, and when cutting a thin plate from the material to be cut, the accuracy of warp, thickness, and parallelism of the thin plate can be improved. It is possible to improve yield and increase productivity.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view of an embodiment of a device for carrying out the cutting method according to the present invention, Fig. 2 is a bottom view of the main part seen from below, and Fig. 3 is a side view of the main part. 4 is a flowchart showing the control process, FIG. 5 is a graph of the displacement amount signal of the inner peripheral blade by the displacement sensor and a graph of the one-rotation pulse signal of the internal peripheral blade, and FIG. 6 is the diagram before application of the present invention. FIG. 7 and FIG. 8 are explanatory diagrams of other embodiments, respectively. 10, 11, and 12 are graphs showing the effects of other embodiments, and FIG. 13 is a plan view of a conventional cutting device. 2...Inner peripheral blade 3...Cutting feed support base 6...Displacement sensor 8...Control unit patent Applicant: Sumitomo Metal Industries, Ltd. (3 others) Agent: Noboru Kono, patent attorney Figure 6 Figure 1] b Figure 7 Figure 8! l (βml Ingo Iytobin 1 to IA firing Kai @ sushi toe tomorrow diagram diagram 1

Claims (1)

[Claims] 1. By rotating the inner peripheral blade which is formed in an annular shape and is provided on the inner peripheral edge thereof, and by relative movement of the cutting feed support stand or the inner peripheral blade in the inner peripheral blade centrifugal direction. In a cutting method in which a workpiece supported by a cutting feed support table is brought into contact with the inner peripheral blade to cut the workpiece, displacement of the blade is detected at one or more locations near the cutting location of the inner peripheral blade. Install a displacement sensor,
A cutting method characterized in that the relative moving speed of the inner peripheral blade of the cutting feed support base in a centrifugal direction is controlled based on a signal from the displacement sensor. 2. The inner peripheral blade, which is formed in an annular shape and is provided on the inner peripheral edge thereof, is rotated and supported on the cutting feed support stand or by relative movement of the inner peripheral blade in the inner peripheral blade centrifugal direction. In the cutting method of cutting the workpiece by bringing the workpiece into contact with the inner peripheral blade, a displacement sensor for detecting the displacement of the blade is provided at one or more locations near the cutting location of the inner peripheral blade,
A cutting method characterized in that the rotation speed of the inner peripheral blade is controlled based on a signal from the displacement sensor. 3. The inner peripheral blade, which is formed in an annular shape and is provided on the inner peripheral edge thereof, is rotated and supported on the cutting feed support stand or by relative movement of the inner peripheral blade in the inner peripheral blade centrifugal direction. In the cutting method of cutting the workpiece by bringing the workpiece into contact with the inner peripheral blade, a displacement sensor for detecting the displacement of the blade is provided at one or more locations near the cutting location of the inner peripheral blade,
Also, there is a weight of 0.2 to 2 kg/cm between the material to be cut and the inner peripheral blade.
2. A cutting method characterized in that a nozzle for blowing gas at a pressure of 2 is provided, and the blowing pressure of the gas from the nozzle is controlled based on a signal from the change sensor.