JPH11277397A - Wire saw processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire saw processing method excellent in practicality by further improving. SOLUTION: In this wire saw processing device, a wire 7 is moved, and the wire 7 is pressed onto a material 1 to be machined while the material is rotated cutting the material. The revolving speed of the material 1 to be machined during the period of time from a starting time to a time when shallow grooves are formed over the outer circumferential surface of the material 1 to be machined, is made lower than its revolution speed later on. By this constitution, the wire 7 can be stably processed without shaking over the processed surface of the material when the processing is started. As the moving direction of the wire 7 is reversed, the rotational direction of the material 1 to be machine is reversed. Before the material 1 to be machined is cut off at its center portion, the rotation of the material 1 to be machined is suspended, and the moving wire 7 is pressed onto the material 1 to be machined in a state of the material 1 to be machine suspended in rotation to cut off the material 1 to be machined at its center portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire saw processing method for grooving or cutting semiconductor material while moving a stretched wire.

[0002]

2. Description of the Related Art As a conventional technique, a wire saw is used for cutting hard and brittle materials and reducing cutting loss of expensive materials. This cutting method applies a slurry (working fluid mixed with abrasive grains) to a wire on which abrasive grains such as diamond have been electrodeposited, or a wire such as a piano wire. Pressing and cutting. Since this cutting is close to the principle of lapping, there is a disadvantage that the processing time is very long.

For this reason, many equipments (multi-wire saws) for winding a wire several times and cutting several tens of materials by one cutting are often used. However, in order to further improve the cutting speed, Japanese Patent Application Laid-Open No. 8-85053 is disclosed. In the publication, the material is driven to swing back and forth.

However, in this method, since the material is driven to reciprocate in a swinging manner, the working is temporarily stopped at both ends, and the working efficiency is low. In addition, there is a problem that a mechanism for swinging becomes complicated, and equipment cost increases due to enhancement of equipment rigidity for suppressing swinging.

[0005] Further, by rotating the work material as disclosed in Japanese Patent Application Laid-Open No. 9-141650, very high efficiency can be obtained. However, in this method, when a material having a solid shape is cut, instead of using a ring-shaped material as described in the publication, a navel (projection) remains. In addition, there is a problem that the wire slips on the surface of the workpiece at the time of starting the processing and the wire is easily shaken.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a wire saw processing method which is further improved and has excellent practicality.

[0007]

According to the wire saw processing method of the present invention, the number of rotations of the workpiece from the start of the processing until a shallow machining groove is formed on the outer peripheral surface of the workpiece is determined. It is characterized by being lower than the rotation speed.

[0008] Therefore, the wire can be stably processed without being blurred on the processed surface at the beginning of the processing. Here, if the rotation direction of the work material is reversed in accordance with the reversal of the moving direction of the wire, the processing can be continued without changing the condition.

Further, as described in claim 3, before cutting at the center of the work material, the rotation of the work material is stopped, and the moving wire is cut with the rotation of the work material stopped. When the material is pressed against the material and cut off at the center of the work material, the occurrence of projections at the center can be suppressed.

[0010] The wire saw processing method according to claim 4 is characterized in that:
Before cutting at the center of the work material, the rotation of the work material is stopped, each thin plate to be cut is held by a holder, and in this state, the moving wire is pressed against the work material and It is characterized by being separated at the center.

Therefore, it is possible to prevent the cut work material from falling apart. Here, as described in claim 5, it is practically preferable that the holder has a hole for draining the working fluid.

[0012] The wire saw processing method according to claim 6 is characterized in that:
It is characterized in that the rotational speed of the work material is increased with the progress of the processing of the work material in the radial direction, so that the peripheral speed of the work material on the outer peripheral contact surface is constant.

Therefore, stable processing can be performed. In the wire saw processing method according to claim 7, the work material is rotatably supported, and after the wire is pressed against the work material in a state where the work material is fixed to form a cut having a predetermined depth,
It is characterized in that the work material is rotated by a predetermined angle, and thereafter, this operation is repeated.

Therefore, when the work material is large and rotation is difficult, the processing location is close to point contact, so that it is efficient. The wire saw processing method according to claim 8 is characterized in that the whole or a part of the work material is processed in a state of being immersed in a processing liquid.

[0015] Therefore, the working fluid (slurry) is reliably supplied to the working location, and the chip removing property is enhanced, and the working efficiency is improved. Here, when the work material is rotated as described in claim 9, the relative speed increases.

Further, when the work material is moved downward, the dipping of the working fluid can be further reduced. A wire saw processing method according to claim 11 is characterized in that a wire is brought into contact with at least two points on a processed cross section of a work material.

Therefore, the processing efficiency can be reliably improved. Here, as described in claim 12, if the wires contacting at two or more places are connected to one, the number of drive systems can be reduced, which leads to a reduction in equipment costs and an improvement in setup.

Further, when the work material is rotated, the relative speed increases. A wire saw processing method according to a fourteenth aspect is characterized in that a groove larger than the diameter of the wire is formed in a processing portion on the outer periphery of the work material before processing.

Therefore, the supply of the working fluid (slurry) can be enhanced. Here, it is practically preferable that the groove has a V-shape as described in claim 15.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a wire saw processing apparatus according to the present embodiment. The work material 1 uses a hard and brittle rod-shaped semiconductor material (ingot), and more specifically, single crystal silicon carbide (SiC). The diameter of the ingot 1 is about 15 mm. The present wire saw processing apparatus cuts the rod-shaped ingot 1 of FIG. 3 by forming a processing groove 26 deeply with a wire saw (7) as shown in FIG. This is a machine for manufacturing the thin plate 25.

FIG. 2 shows a cross section of the side of the wire saw processing apparatus, and FIG. 3 shows a cross section of the front of the wire saw processing apparatus. As shown in FIG. 3, this apparatus includes a work material rotating motor 2, and a support plate 3 is provided on an output shaft 2a. One end surface of the bar-shaped work material 1 is bonded to the support plate 3 with wax, and the bar-shaped work material 1 is supported in a state of extending in the horizontal direction. Therefore, the work material 1 can be rotated by driving the motor 2. The rotation speed of the motor 2 (workpiece 1) is 1 to several tens rpm.
It is.

A pressing roller 4 is disposed on the other end surface of the rod-shaped workpiece 1, and moves to a position shown by a broken line in FIG. 3 to support the workpiece 1 when the workpiece 1 rotates. .
That is, the rotation is stabilized even when the long work material 1 is processed by the pressing roller 4. However, just before the work material 1 is completely cut, the pressing roller 4 separates from the work material 1 (the position shown by the solid line in FIG. 3). This prevents the wire 7 from being crushed while being pinched by the pressing pressure.

As shown in FIG. 1, bar-shaped pulleys 5 and 6 are rotatably supported above the bar-shaped workpiece 1, and a number of wires 7 are parallel between the pulleys 5 and 6, and , Which are stretched horizontally. This wire 7 is composed of a single wire, and as shown in FIG.
12, and both ends of the pulley 9 are fixed. The pulley 9 is connected to an output shaft of a wire moving motor 13 so that the wire 7 can be moved by driving the motor 13. The pulleys 5 and 6 in FIG. 2 can move up and down, and the wire 7 stretched in a horizontal state is moved up and down by the up and down movement of the pulleys 5 and 6.

In this embodiment, a piano wire having a diameter of 0.2 mm is used as the cutting wire 7 and its length is about 30 m. The cutting wire 7 reciprocates while its moving direction is reversed. Further, the wire feed speed is 1 to 5 m / sec, and the wire processing load is 50
~ 200g, and wire tension is 1000 ~ 35
00 g.

As shown in FIGS. 1 and 2, a slurry nozzle 15 is provided above the rod-shaped work material 1, and a slurry 16 is supplied from the nozzle 15 toward the work material 1. ing. Here, the slurry 16 is a mixture of water, glycerin and diamond powder.

A slurry scattering cover 17 is provided above the rod-shaped workpiece 1, and the cover 17 prevents the slurry 16 from scattering. That is, in the processing using the method of rotating the work material 1, the slurry 16 is easily scattered in the equipment, but the cover 17 is provided on the work material 1, so that the slurry can be prevented from being scattered. . The end of the slurry scattering cover 17 is shaped and positioned so as not to interfere with the wire 7.

Further, an air nozzle 18 is provided at an end of the slurry scattering cover 17, and air 19 is jetted from the air nozzle 18. That is, by blowing out the air 19 in a curtain shape, the scattering of the slurry 16 is further suppressed, and the effect of dropping the abrasive particles attached to the wire 7 is obtained.

Below the bar-shaped workpiece 1, a workpiece holder 2 is provided.
0 is arranged. The work holder 20 is for holding the wafer after cutting. That is, in the method in which the work material 1 is rotated, the work material holder 2 is provided below the work material 1 in order to prevent the cut work material 1 from falling apart.
By providing 0, falling is prevented. More specifically,
The body 21 of the work holder 20 has a semicircular cylindrical shape,
As shown in FIG. 2, the sectional shape is a concave shape for receiving the work material 1. As shown in FIG. 3, a large number of projections 22 are formed on the bottom surface of the main body 21. The projections 22 are inserted into the processing grooves 26 formed by the wires 7 as shown in FIG. 11 as shown in FIG. That is, the wafer 25 is held upright between the projections 22. The projection width (X value in FIG. 11) is preferably large enough to enter the machining groove 26 without tilting the work material 1.
Is slightly smaller than the removal width Y (the sum of the loss due to the wire diameter and the inclination of the rotation and the cutting loss due to the abrasive grains), and the interval Z is the thickness of the workpiece 1 (wafer 25) to be cut. The width is slightly wider than W.

Further, as shown in FIG.
A number of holes (through-holes) 23 for removing a slurry are formed on the bottom surface of the main body (dish-shaped body) 21. The holes 23 allow the slurry accumulated inside to be removed. As described above, the slurry discharge path is formed by the slurry removal hole 23, so that the contamination in the next step can be prevented, and the slurry using an expensive diamond can be prevented from being taken out of the machine.

A moving arm 24 extends from the main body 21 of the workpiece holder 20, so that the arm 24 can be driven up and down. The holder 20 has a shape that does not interfere with the wire 7 (θ in FIG. 2 is 180 degrees or less).
The position is below the center of rotation of the work material 1. The work material holder 20 can be used as a case for the work material 1 and can also be used for transport to the next step of cleaning.

FIG. 4 is a diagram showing an electrical configuration of the wire saw processing apparatus. In FIG. 4, the wire saw processing apparatus includes a microcomputer (hereinafter, referred to as a microcomputer) 30. The microcomputer 30 has a start switch 31
And the height sensor 32 are connected. Start switch 31
Is operated by the operator, the signal is sent to the microcomputer 30. The height sensor 32 detects the height H from the center of the workpiece 1 in the vertical direction to the position of the cutting wire 7 as shown in FIG. Results are sent.

The microcomputer 30 shown in FIG. 4 is connected to the wire moving motor 13, the work material rotating motor 2, the guide pulley moving motor 33, the pressing member moving motor 34, and the work material holder moving motor 35. ing. As previously mentioned,
The wire 7 is moved by the drive of the wire moving motor 13, and the work material 1 is rotated by the drive of the work material rotating motor 2. The guide pulley moving motor 33 is a motor for moving the guide pulleys 5 and 6 in FIG. The pressing member moving motor 34 is a motor for moving the pressing member 4 in FIG. The work holder moving motor 35 is a motor for moving the work holder 20 up and down. The microcomputer 30 controls the driving of these motors 13, 2, 33, 34, 35.

Next, the operation of the wire saw processing apparatus thus configured will be described. First, a work material 1 to be processed is prepared. The work material 1 has an orientation flat as shown in FIG. Then, as shown in FIG. 3, one end surface of the bar-shaped work material 1 is attached to the support plate 3 with wax. This is set in the processing device.

When the start switch 31 of FIG. 4 is pressed, the microcomputer 30 drives the pressing member moving motor 34 to move the pressing roller 4 of FIG. 3 from the position indicated by the solid line in FIG. 3 to the position indicated by the broken line in FIG. The work material 1 is supported by the pressing roller 4. Thereafter, the microcomputer 30 starts driving the wire moving motor 13 and the work material rotating motor 2 and drives the guide pulley moving motor 33 to drive the wire 7.
Start the downward movement. That is, the wire saw processing is started in which the wire 7 is pressed against the work material 1 while moving the wire 7 and the work material 1 is rotated to cut the work material 1. At this time, as shown in FIG. 5, the microcomputer 30 drives the wire moving motor 13 to reverse the wire moving direction (timing of t1, t2, t3, t4 in FIG. 5). When the wire moving direction is reversed by controlling the material rotating motor 2, the rotating direction of the work material 1 is also reversed. In other words, when the wire moving motor 13 rotates forward,
The wire 7 moves in the direction indicated by α, and when the motor 13 rotates forward, the work material rotating motor 2 rotates forward and the work material 1 rotates in the direction indicated by β in FIG. As shown, when the motor 13 rotates in the negative direction, the motor 2 also rotates in the negative direction.

As described above, if the direction of rotation of the work material 1 is also reversed when the direction of movement of the wire is reversed, the machining can be continued without changing the condition as compared with the case where the direction of rotation of the work material 1 is constant. it can.

As described above, by rotating the workpiece 1 in addition to the movement of the wire 7, the cutting speed when the workpiece 1 (about 15 mm in diameter) is not rotated is about 17 minutes (the cutting capacity is 10.0 mm ^2). / Min), but by rotating, the cutting speed is about 11 minutes (cutting capacity 16.0 m
m ² / min). Also, in the method of fixing the work material 1, a rough saw mark (working trace of the wire) is attached about 1.0 μm in parallel with the moving direction of the wire, but when the work material 1 is rotated, the saw mark becomes 0.3 μm.
And become very small. Further, by rotating the work material 1, the flatness is also improved.

As shown in FIG. 6, the relationship between the moving speed of the wire 7 and the number of revolutions of the work material rotating motor 2 is as follows.
Processing is started at timing t11 to keep the moving speed of the wire 7 constant, and the rotation speed of the work material rotating motor 2 is reduced to about 1 rpm from the timing of t11 to the timing of t12 after a predetermined time has elapsed. Rotation. During the period from t11 to t12, a shallow machining groove 26 is formed on the outer peripheral surface of the work material 1. More specifically, the unprocessed portion 1b of the work material (ingot) 1 including the orientation flat has a circular shape as shown in FIG. Thereafter, as shown in FIG. 6, the rotation speed of the work material rotating motor 2 is increased. Thereby, in the method of rotating the work material 1 in addition to the movement of the wire 7, it is possible to prevent the wire 7 from blurring on the processing surface when the processing is started. That is, after the start of processing, a processing groove of the wire 7 is formed t1.
If the wire is rotated at a low speed until the timing of 2, and then the rotation is increased, a rotation trajectory for stably driving is formed, and the blur of the wire 7 can be suppressed.

On the other hand, when the work material 1 is processed while moving the wire 7 and rotating the work material 1 from the state shown in FIG. 2, the state shown in FIG. 9 is obtained. , The microcomputer 30 detects the height H based on a signal from the height sensor 32. More specifically, the microcomputer 30 detects the position H of the wire drive system by the height sensor 32, and further corrects the position H in consideration of the deflection ΔH of the wire 7 as shown in FIG. Position) is determined. That is, as shown in FIG.
2, the height H is measured, and the value (= H + ΔH) obtained by adding the corrected height ΔH due to the deflection of the wire 7 is detected as the height of the wire contact portion. The deflection ΔH of the wire 7 varies depending on the tension of the wire 7, the cutting load tension (there may be a cutting feed speed) and the hardness of the work material 1. I remember.

Further, as shown in FIG. 6, in the relationship between the rotation speed of the work material rotating motor 2 and the height H, the height H is gradually reduced after the timing t12, and The rotation speed of the rotation motor 2 is gradually increased.
Thus, cutting is continued with the peripheral speed v kept constant. That is, as shown in FIG. 7, when the diameter of the work material 1 is large (the locus of AB) and when it is small (A′-B ′).
Trajectory), the moving speed of the wire contact surface is kept constant (L2 = L1). More specifically, when the work material 1 is processed at a constant rotation speed, the outermost peripheral portion of the work material 1 has a high peripheral speed, so that the cut amount per unit time is large, and the processed surface is also excellently finished. However, the processing speed becomes rougher as the peripheral speed decreases as it approaches the center. For this reason, the rotation speed of the work material 1 is increased so that the peripheral speed becomes constant as the processed portion approaches the center.

Further, by cutting the work material 1 further, FIG.
As shown at 0 and 11, the timing is approaching when the workpiece 1 is cut off at the center. The timing of t14 in FIG. 6 is the timing of separation at the center of the work material 1. At the timing of t13 immediately before the separation timing t14, the microcomputer 30 stops the drive of the work material rotating motor 2. That is, the microcomputer 30 has a height H (more precisely, H
When (+ ΔH) reaches the predetermined value H1, the driving of the motor 2 is stopped. Then, the microcomputer 30 drives the work holder moving motor 35 to move the holder 20 upward from the state shown in FIG. 11 to move the holder 20 into the processing groove 26 formed by the wire 7 as shown in FIG. Insert the projection 22 of the holder into the holder. Thereafter, the microcomputer 30 drives the pressing member moving motor 34 to separate the pressing roller 4 from the workpiece 1, and releases the supporting of the workpiece 1 by the roller 4. Then, in a state where each wafer 25 is held by the holder 20, the wire 7 is moved downward to be cut (cut off).

That is, when cutting is completed in a state where the work material 1 is simply rotated at the time of cutting, a projection remains at the center of rotation. These projections increase the processing time when performing surface grinding in the next step. Especially hard Si
C takes a lot of time. Therefore, in order to reduce the occurrence of projections at the center, the rotation is stopped just before the work material 1 is cut, and the microscopic region is cut off in the stopped state. Can be

The position H1 (see FIG. 6) at which the rotation of the workpiece 1 is stopped can be managed by time if the ingot (product) 1 is always the same. When the workpiece 1 is cut off from the state shown in FIG.
Since the workpiece 5 is held, the wafer 25 does not tilt until the workpiece 1 is completely cut. Thereby, the flatness of the central portion of the work material 1 can be improved.

As described above, this embodiment has the following features. (A) In the wire saw processing method of cutting the work 1 by pressing the wire 7 against the work 1 while rotating the work 1 while moving the wire 7, t11 to t in FIG.
As shown in 12, the rotation speed of the work material 1 from the start of processing to the formation of the shallow processing groove 26 on the outer peripheral surface of the work material 1 was set lower than the subsequent rotation speed. Therefore, the wire 7 does not shake on the processing surface at the beginning of the processing,
Processing can be performed stably. (B) As shown in FIG. 5, the direction of rotation of the work material 1 is reversed with the reversal of the moving direction of the wire 7, so that the processing can be continued without changing the conditions. (C) t1 in FIG.
At timing 3, before cutting at the center of the work material 1, the rotation of the work material 1 is stopped, and the moving wire 7 is pressed against the work material 1 while the work material 1 is stopped rotating. Since the cutting is performed at the center of the work material 1, the occurrence of projections at the center can be suppressed. (D) In the wire saw processing method of cutting the work material 1 by pressing the wire 7 against the work material 1 while moving the wire 7 and rotating the work material 1, before cutting at the center portion of the work material 1, The rotation of the work material 1 is stopped, and each wafer 25 (thin plate) to be cut is held in the holder 20 as shown in FIG.
In this state, the moving wire 7 is
And cut off at the center of the work material 1. Therefore, it is possible to prevent the cut work material 1 from falling apart. (E) In a wire saw processing method for cutting the work material 1 by pressing the wire 7 against the work material 1 while moving the wire 7 and rotating the work material 1, t12 to t in FIG.
In the period of 13, the rotational speed of the work material 1 is increased with the progress of the processing of the work material 1 in the radial direction so that the peripheral speed of the work material 1 at the outer peripheral contact surface is constant. did. Therefore, stable processing can be performed. (F) As shown in FIG.
3 is provided, which is practically preferable. (Second Embodiment) Next, a second embodiment will be described with reference to the first embodiment.
The following description focuses on the differences from this embodiment.

In this embodiment, as shown in FIG. 13, the drive of the work material rotating motor 2 (the rotation of the work material 1) is intermittent, and as shown in FIG. The wire 7 is pressed against the work material 1 in a state where the work material 1 is fixed to the material before processing as shown in (b) to form a cut 40 having a predetermined depth d1. This processing corresponds to t20 to t21 in FIG.
It is performed during the period. Thereafter, t21 to t22 in FIG.
In the period of (1), as shown in FIG.
Only the work material 1 is rotated. At this time, since the end of the unprocessed portion rotates as the outer diameter (radial distance), it is necessary to temporarily return to the upper portion so as not to catch the wire 7 to avoid the length from the rotation center to the end. Is desirable. Then, in a period from t22 to t23 in FIG. 13, the wire 7 is pressed against the work material 1 while the work material 1 is fixed, and a predetermined depth d is set.
2 (= d1) cuts 41 are formed. Further, FIG.
In the period from t23 to t24 of FIG. 3, the wire 7 is rotated by a predetermined angle θ2 (= θ1) as shown in FIG. 14D, and the wire 7 is pressed against the work material 1 while the work material 1 is fixed. A notch 42 having a depth d3 (= d1 = d2) is formed. Hereinafter, this is repeated.

That is, when the work 1 is large and it is difficult to rotate, the work is performed with the work 1 (work) stopped, and the work is slightly indexed when the work has progressed to some extent. By doing so, the removal point becomes closer to point contact, which is more efficient.

As described above, this embodiment has the following features. (A) In a wire saw processing method in which the wire 7 is pressed against the work material 1 while moving the wire 7, and the work material 1 is cut, the work material 1 is rotatably supported and the work material 1 is fixed. The wire 7 is pressed against the workpiece 1 to a predetermined depth d1.
After the notch 41 is formed, the work material 1 is rotated by a predetermined angle θ1, and this is repeated thereafter. Therefore, when the workpiece 1 is large and rotation is difficult, the processing location is close to point contact, which is efficient. (Third Embodiment) Next, a third embodiment will be described with reference to the first embodiment.
The following description focuses on the differences from this embodiment.

FIGS. 15 and 16 show a wire saw processing apparatus according to this embodiment. The apparatus includes a slurry tank 50, and the tank 50 is filled with a slurry 51. A suction pipe 52 is connected to the bottom of the slurry tank 50,
A circulation pump 53 is connected to the suction pipe 52. The liquid discharged from the circulation pump 53 is returned to the bottom of the tank 50 by the stirring nozzle 54 and is supplied to the vicinity of the processing section by the nozzle 55. By circulating the liquid in this manner, the abrasive grains of the slurry 51 are likely to settle in the tank 50, but the settling of the abrasive grains is prevented by stirring the liquid. In addition,
Instead of the liquid circulation by the pump 53, the abrasive grains may be agitated by using an air pump, an ultrasonic vibrator or the like.

Then, the processed portion of the work material 1 is immersed in the slurry 51 in the tank 50, and processing is performed in this state. In addition, the rotation unit and the wire-driven pulleys 5, 6 and the like come into contact with the slurry 51 containing abrasive grains, so that deterioration is easily caused. In addition, a large tank 50 is required to immerse the entire work material 1. Therefore, pulleys 5 and 6 are about half
The workpiece 1 is immersed in the slurry 51 and immersed in the slurry 51, and the workpiece 1 is processed by moving the workpiece 1 downward.

The other configuration is the same as that of the first embodiment, and the description thereof will be omitted by retaining the same reference numerals.
The work 1 is processed while being rotated. Note that the work material 1 is the same as the slurry (working fluid) 51 in FIGS.
6 is a part, but the whole may be immersed.

As described above, in the present embodiment, as another means for increasing the efficiency, the processing portion of the workpiece 1 is
To ensure that the slurry 51 is supplied to the processing point. Therefore, the chip removing property is improved, and the processing efficiency is improved.

As described above, this embodiment has the following features. (A) In the wire saw processing method in which the work material 1 is cut while moving the wire 7, the work material 1 is processed in a state of being immersed in the slurry (working liquid) 51 in whole or in part, so that the work material 1 is surely processed. The processing liquid (slurry) 51 is supplied to the processing location, thereby improving the chip removal performance and improving the processing efficiency. (B) Since the work material 1 is rotated, the relative speed increases, which is practically preferable. (C) Since the work material 1 is moved downward, the immersion of the slurry 51 can be further reduced. (Fourth Embodiment) Next, a fourth embodiment will be described with reference to the first embodiment.
The following description focuses on the differences from this embodiment.

In this embodiment, as shown in FIG. 17, the wire 7 is positioned so as to be in contact with the upper and lower surfaces of the work material 1. In other words, it has a configuration having two processing points, and the pair of pulleys 5 and 6 move down and the pair of pulleys 5 'and 6' move up, so that the processing proceeds toward the processing center. .

However, in the case of the final cutting, since the wires, pulleys and the like interfere with each other, the cutting must be completed with one wire. The wire 7 used at this time
, One wire is routed by a pulley. By doing so, the number of drive systems (motors) can be reduced, which leads to a reduction in equipment costs and an improvement in setup. The work 1 is processed while being rotated.

As described above, the number of processing points is increased as an alternative to the first to third embodiments for increasing the efficiency. This makes it possible to reliably improve the processing efficiency.

As described above, this embodiment has the following features. (A) In a wire saw processing method in which the wire 7 is pressed against the work material 1 while moving the wire 7 and the work material 1 is cut, the wire 7 is brought into contact with two or more locations in the processing cross section of the work material 1. Therefore, processing efficiency can be reliably improved. (B) Since the wires 7 contacting at two or more locations are connected to one wire, the number of drive systems can be reduced, which leads to a reduction in equipment costs and an improvement in setup. (C) Since the work material 1 is rotated, the relative speed increases, which is practically preferable.

Although FIG. 17 has two processing points, the number of processing points may be three or more. Also in this configuration, the efficiency is further improved by further combining the rotation mechanism with the third embodiment. (Fifth Embodiment) Next, a fifth embodiment will be described with reference to FIG.
The following description focuses on the differences from this embodiment.

In this embodiment, the work material 1 before processing is
As shown in FIG. 18A, a groove 60 having a diameter larger than the diameter of the wire 7 is formed in a processing portion on the outer periphery of the work material 1. This groove 60 has a V-shape, and FIG.
As shown in FIG. 7, the width is larger than the width of the groove 26 formed by the wire 7. The cross-sectional shape of the groove 60 may be a U-shape other than the V-shape. The grooves 60 are formed using other equipment (for example, a grinder) before processing. Alternatively, the groove is formed by a wire saw that is larger than the width of the groove 26 formed by the wire 7.

Then, it is set in the wire saw processing apparatus described with reference to FIGS. Then, as shown in FIG. 18 (b), the wire 7 enters into the groove 60 and the processing proceeds, and the wire 7 is cut as shown in FIG. 18 (c).

At the time of this processing, the wire 7 having a diameter of 0.2 mm is used. However, it is difficult to supply slurry into the processing groove 26 formed by the wire 7. On the other hand, when the groove 60 is provided on the outer periphery of the work material 1, slurry is easily supplied. Thereby, slurry supply property is improved and cutting property is improved. Also, the wafer 25 in FIG.
Is chamfered by the groove 60, which is practically preferable. That is, when the wafer is used as a wafer, the outer peripheral portion is chamfered. By forming the V-shaped groove 60 in advance, the chamfering can be eliminated or the number of processing steps for chamfering can be reduced.

As described above, this embodiment has the following features. (A) In a wire saw processing method in which the wire 7 is pressed against the work material 1 while the wire 7 is moved and the work material 1 is rotated, the wire 1 is cut into the processing portion on the outer periphery of the work material 1 by cutting the work material 1. A groove 60 larger than the diameter of No. 7 was formed before processing. Therefore, the supply of the slurry can be improved. (B) Since the groove 60 has a V-shaped cross-sectional structure, it is practically preferable.

In the above description, the work material is Si
Although it was C, it may be applied when processing silicon or the like. That is, the present invention is not limited to the SiC wafer and may be applied to the manufacture of a large-diameter silicon wafer (for example, a 12-inch wafer).

In the above description, the case where the material is cut has been described, but the present invention may be applied to the case where the material is grooved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wire saw processing apparatus according to a first embodiment.

FIG. 2 is a cross-sectional view of a side surface of the wire saw processing apparatus.

FIG. 3 is a cross-sectional view at the front of the wire saw processing apparatus.

FIG. 4 is a diagram showing an electrical configuration.

FIG. 5 is a time chart for explaining the operation.

FIG. 6 is a time chart for explaining the operation.

FIG. 7 is a diagram for explaining a peripheral speed.

FIG. 8 is a view for explaining a height position.

FIG. 9 is a cross-sectional view during processing.

FIG. 10 is a cross-sectional view during processing.

FIG. 11 is a cross-sectional view during processing.

FIG. 12 is a cross-sectional view during processing.

FIG. 13 is a time chart illustrating a wire saw processing apparatus according to a second embodiment.

FIG. 14 is a sectional view showing a processing procedure.

FIG. 15 is a perspective view of a wire saw processing apparatus according to a third embodiment.

FIG. 16 is a sectional view of the wire saw processing apparatus.

FIG. 17 is a sectional view of a wire saw processing apparatus according to a fourth embodiment.

FIG. 18 is a cross-sectional view for explaining a wire saw processing method according to the fifth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Work material, 7 ... Wire, 20 ... Work material holder, 25 ...
Wafer, 51 ... Slurry, 60 ... Groove

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tatsuyuki Hanazawa 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation (72) Inventor Yasuo Kito 1-1-1, Showa-cho, Kariya-shi, Aichi Co., Ltd. Inside DENSO

Claims (15)

[Claims] 1. A wire saw processing method for cutting a work material by pressing the wire against the work material while moving the wire and rotating the work material, wherein a shallow machining groove is formed on the outer peripheral surface of the work material from the start of processing. A method for processing a wire saw, wherein the number of revolutions of a work material before being formed is lower than the number of revolutions thereafter. 2. The method according to claim 1, wherein the direction of rotation of the workpiece is reversed with the reversal of the moving direction of the wire. 3. The cutting of the work material is stopped before cutting at the center portion of the work material, and the moving wire is pressed against the work material in a state in which the rotation of the work material is stopped. 2. The wire saw processing method according to claim 1, wherein the wire saw is separated at a portion. 4. A wire sawing method for cutting a work material by pressing the wire against the work material while moving the wire and rotating the work material, wherein the work material is cut before being cut at a central portion of the work material. A wire saw processing method, wherein the rotation is stopped, each thin plate to be cut off is held by a holder, and in this state, the moving wire is pressed against the work and cut off at the center of the work. . 5. The wire saw processing method according to claim 4, wherein the holder has a hole for draining a processing liquid. 6. A wire saw processing method for cutting a work material by pressing the wire against the work material while moving the wire and rotating the work material, wherein the work is performed as the work in the radial direction of the work material progresses. A method for processing a wire saw, characterized in that the number of revolutions of the material is increased so that the peripheral speed on the outer peripheral contact surface of the workpiece is constant. 7. A wire sawing method for cutting a work material by pressing the wire against the work material while moving the wire, wherein the work material is rotatably supported and the wire is cut in a state where the work material is fixed. A method for processing a wire saw, comprising: forming a cut having a predetermined depth by pressing against a material, rotating the work material by a predetermined angle, and thereafter repeating the process. 8. A wire saw processing method for cutting a workpiece while moving a wire, wherein the workpiece is entirely or partially immersed in a processing liquid. 9. The wire saw processing method according to claim 8, wherein the work material is rotated. 10. The wire saw processing method according to claim 8, wherein the work material is moved downward. 11. A wire saw processing method for cutting a work material by pressing the wire against the work material while moving the wire, wherein the wire is brought into contact with at least two positions in a processed cross section of the work material. Wire saw processing method. 12. The wire saw processing method according to claim 11, wherein the wires contacting at two or more locations are connected to one wire. 13. The wire saw processing method according to claim 11, wherein the work material is rotated. 14. A wire saw processing method for cutting a work material by pressing the wire against the work material while moving the wire and rotating the work material, wherein a processing portion on an outer periphery of the work material has a diameter smaller than a diameter of the wire. A wire saw processing method, wherein a thick groove is formed before processing. 15. The wire saw processing method according to claim 14, wherein the groove has a V-shape.