JPH10166255A - Wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform cutting work of a wire saw without causing fluctuation in working load even if a cutting length varies with cutting work for a work. SOLUTION: A wire 15 is wound at a preset pitch between working rollers 13, 14. Slurry is supplied onto the wire 15 while the wire 15 is running, and a work 21 is put in contact with the wire 15 to perform cutting work for time work 21. In cutting work for the work 21, working load is detected by a working load detector 44. In accordance with a result, detected by the detector 44, a controller 38 controls the running speed of the wire 15 and the supply amount of the slurry to keep working load per unit cutting length of the work 21 constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire saw for cutting a workpiece made of a hard and brittle material such as a semiconductor material, a magnetic material, and a ceramic using a wire.

[0002]

2. Description of the Related Art In a wire saw of this type, a plurality of processing rollers are disposed at predetermined intervals, and a plurality of annular grooves are formed at a predetermined pitch on the outer periphery of the rollers. In addition, one wire is sequentially wound around the annular groove between the processing rollers. Then, while the wire is running at a predetermined speed, an aqueous or oily slurry containing loose abrasive grains is supplied onto the wire, and in this state, the work is pressed against the wire and is brought into contact with the wire, and the work is cut into slices. It is to be processed.

[0003]

However, in a conventional wire saw, for example, as shown in FIG. 5, when a columnar work is cut, the work is cut from the position P1 to the positions P2, P3 and P3. When sequentially proceeding to P4, the actual cutting length of the workpiece changes and the processing load fluctuates. That is, the cutting is performed from the position P1 to the position P3.
During this process, the cutting length of the workpiece increases, and the processing load is gradually increased. Further, the cutting is performed from the position P3 to the position P4.
During the process, the cutting length of the work is reduced, and the processing load is gradually reduced.

As described above, as the cutting of the workpiece progresses,
When the cutting length changes and the processing load changes, the thickness of the cut wafer and the surface roughness of the cut surface change depending on the cut position. In other words, there is a problem that the thickness of the wafer becomes thinner and the surface roughness becomes rougher in a portion where the processing load is large as compared with a portion where the processing load is small, and the processing accuracy is reduced. This has been found to occur because the supply amount of the slurry supplied for cutting is constant despite the cutting length becoming longer. On the other hand, in the case of an initial light load, excessive slurry not used for cutting is supplied, which may cause thermal deformation of the machine.

[0005] The present invention has been made by paying attention to such problems existing in the prior art. The purpose is that even if the cutting length changes with the cutting of the workpiece, the cutting can be performed without causing a change in the processing load, and the thickness of the cut wafer and the surface of the cut surface can be cut. It is an object of the present invention to provide a wire saw that can prevent roughness from changing depending on a cutting position and can improve processing accuracy.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, in a wire saw, a detecting means for detecting a processing load when cutting a workpiece, and a detection result of the detecting means. And control means for adjusting and controlling the supply of the slurry based on the above.

According to a second aspect of the present invention, in the wire saw according to the first aspect, the control means adjusts at least one of a traveling speed of the wire, a supply amount of the slurry, and a pressing force of the work on the wire. By doing
The processing is controlled so that the processing load per unit cutting length of the work is kept constant.

According to a third aspect of the present invention, in the wire saw according to the first or second aspect, the detecting means detects a machining load by measuring a current or an electric power to a wire traveling motor. It was made.

In the wire saw according to the first aspect, while the wire is running, a slurry is supplied onto the wire, and the workpiece is brought into contact with the wire to cut the workpiece into a slice. . At the time of cutting the work, the processing load is detected by the detecting means. Then, the supply of the slurry is adjusted and controlled by the control means based on the detection result. For this reason, even when the cutting length changes depending on the cutting position of the work as in the case of cutting a cylindrical work, the processing load does not fluctuate.

[0010] In the wire saw according to claim 2,
By controlling the traveling speed of the wire and the supply amount of the slurry by the control means, the processing load per unit cutting length of the work is maintained and controlled to be constant. For this reason, the processing load can be adjusted in response to a change in the cutting length during the cutting.

[0011] In the wire saw according to the third aspect,
The processing load is detected by measuring the current or power to the wire traveling motor by the detecting means. For this reason, it is possible to accurately detect a change in the processing load during the cutting processing.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the wire saw according to the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the cutting mechanism 11 is mounted on an apparatus base 12. The cutting mechanism 11 includes a processing drive roller 13 and a processing driven roller 14 extending in parallel, and annular grooves 13a and 14a are formed on the outer periphery thereof at a predetermined pitch. In the drawings, the number of the annular grooves 13a and 14a is less than the actual number for easy understanding.

A wire 15 made of one wire is continuously wound around each of the annular grooves 13a and 14a of the processing rollers 13 and 14. The wire running motor 16 is disposed on the apparatus base 12. When the processing drive roller 13 is directly rotated by the motor 16, the driven roller 14 is rotated via the wire 15. The rotation of the processing rollers 13 and 14 causes the wire 15 to run at a predetermined running speed. The traveling of the wire 15 is performed by moving forward by a certain amount (for example, 10 m) and retreating by a certain amount (for example,
m) is repeated so as to advance progressively as a whole.

A work supporting mechanism 19 is supported by a column 20 erected on the apparatus base 12 so as to be able to move up and down so as to be located above the cutting mechanism 11, and a work made of a hard and brittle material is provided below the work supporting mechanism 19. 21 is set detachably. The work elevating motor 22 is disposed on the column 20, and the work support mechanism 19 is vertically moved by the motor 22 via a ball screw (not shown) or the like. Slurry supply mechanism 3
Reference numeral 4 denotes a plurality of slurry supply pipes 35 disposed above the cutting mechanism 11 and extending in parallel with the processing rollers 13 and 14.
It has.

During operation of the wire saw, the work supporting mechanism 19 is lowered toward the cutting mechanism 11 while the wire 15 is running between the processing rollers 13 and 14 of the cutting mechanism 11. At this time, an aqueous or oily slurry containing loose abrasive particles is supplied from the slurry supply pipe 35 of the slurry supply mechanism 34 onto the wire 15, and the work 21 is pressed against the wire 15 and is brought into contact with the wire 15. 21 is cut into a slice.

A reel mechanism 23 is mounted on the apparatus base 12, and is a feed reel 24 for feeding the wire 15.
And a winding reel 25 for winding the wire 15. A pair of reel rotation motors 26 and 27 each composed of a servomotor whose rotation direction and rotation speed can be changed are arranged on the apparatus base 12, and reels 24 and 25 are connected to their motor shafts via a transmission mechanism (not shown). Are linked.

The traverse mechanism 28 includes the reel mechanism 23
Is mounted on the device base 12 adjacent to the
The feeding of the wire 15 from the wire 4 and the winding of the wire 15 to the take-up reel 25 are guided while traversing up and down. The two reels 24, 2 of the reel mechanism 23
5, the wire 15 is paid out from the pay-out reel 24 to the cutting mechanism 11, and the processed wire 1 is
5 is wound on a take-up reel 25.

The tension applying mechanism 29 and the guide mechanism 30
It is arranged between the reel mechanism 23 and the cutting mechanism 11. Then, the processing rollers 13 and 14 of the cutting mechanism 11
Both ends of the wire 15 wound between them are hung on the tension applying mechanism 29 via the respective guide rollers 31 of the guide mechanism 30. In this state, a predetermined tension is applied to the wire 15 between the processing rollers 13 and 14 by the tension applying mechanism 29.

The tension reducing mechanism 32 is disposed between the reel mechanism 23 and the tension applying mechanism 29, and includes a pair of rotating rollers 33. The wire 15 is wrapped around these rotating rollers 33, and by rotating both rotating rollers 33, the tension imparting mechanism 29 is moved from the reel mechanism 23
The tension of the wire 15 which spreads to each of the reels 24 and 25 is reduced.

Next, a control device for controlling the processing load during the cutting of the work 21 will be described. As shown in FIGS. 2 and 3, a control device 38 as a control means is disposed near the device base 12, and a central processing unit (CPU) 39 and a memory 40 are mounted therein.
The CPU 39 stores a program for controlling the operation of the entire apparatus, and the memory 40 temporarily stores various input data and detection data.

An operation panel 41 is mounted on the front of the control device 38, and various switches such as a start switch and an indicator lamp are arranged on the operation panel 41. The keyboard 42 is arranged at the front of the operation panel 41, and a number of input keys 43 are arranged there. Then, various data such as a processing load serving as a reference per unit cutting length is input from the keyboard 42 to the CPU 39.

A machining load detector 44 as a detecting means is attached to the side of the wire traveling motor 16 and is used to detect the workpiece 2.
At the time of the first cutting, the current or electric power to the wire traveling motor 16 is measured to detect the machining load. And
A detection signal of the processing load detected by the processing load detector 44 is input to the CPU 39 and compared with a reference processing load value, an actual processing load with respect to the reference processing load is calculated, and the processing load is fixed. Is provided for control.

The driving circuits 45 and 4 are provided from the CPU 39.
6, 47, 48 through the wire running motor 1
6. The drive control signal is output to the reel rotation motor 26, the take-up reel rotation motor 27, and the slurry supply amount adjusting device 49 of the slurry supply mechanism 34. The slurry supply amount adjusting device 49 includes a circulation pump or a flow control valve connected to a supply pipe of the slurry supply mechanism 34, and the rotation speed of the circulation pump or the opening of the flow control valve is adjusted. The circulation flow rate of the slurry is adjusted. The running speed of the wire 15 is adjusted by changing the speed of each of the motors 16, 26, 27.

Next, the operation of the wire saw configured as described above will be described. Well, in this wire saw,
The wire 15 is paid out from the pay-out reel 24 of the reel mechanism 23, and is wound up on the take-up reel 25 while repeating stepwise running of advancing and retreating between the processing rollers 13 and 14 of the cutting mechanism 11 for a fixed amount. . And
While the slurry containing the loose abrasive particles is supplied from the slurry supply pipe 35 of the slurry supply mechanism 34 onto the wire 15 between the processing rollers 13 and 14, the work 21 is lowered with respect to the wire 15 by lowering the work support mechanism 19. Are pressed and contacted. Thereby, the work 21 is cut to a predetermined thickness.

At the time of cutting the work 21, if the work 21 has a cylindrical shape as shown in FIGS. 1 and 5, the cutting of the work 21 by the wire 15 is performed from the position P1 to the positions P2, P3 and P3. When proceeding to P4 in order,
The actual cutting length of the workpiece 21 changes, and the processing load changes. That is, while the cutting proceeds from the position P1 to the position P3, the cutting length of the work 21 increases, and the processing load gradually increases. Further, the cutting is performed from the position P3 to the position P4.
During this process, the cutting length of the work 21 is reduced, and the processing load is gradually reduced.

This change in the processing load is detected by the processing load detector 4
By measuring the current flowing through the wire running motor 16 or its power at 4, it is detected as needed and the CPU 39
Is input to Then, based on the detection result of the processing load, the CPU 39 changes the rotation speed of the motors 16, 26, and 27, and adjusts the slurry supply amount adjusting device 49 so that the traveling speed of the wire 15 and the supply of the slurry are adjusted. The amount is adjusted. Thereby, the adjustment control is performed so that the processing load per unit cutting length of the work 21 becomes constant.

That is, as shown in FIG. 4, while the cutting position shifts from the position P1 to the position P3 and the processing load is increased with the increase in the cutting length of the work 21, the wire 1
5, and the supply amount of the slurry is increased. In addition, while the cutting position shifts from the position P3 to the position P4 and the cutting load of the work 21 is reduced and the processing load is reduced, the traveling speed of the wire 15 is reduced and the slurry supply amount is reduced. Is done. For this reason,
Even if the cutting length changes as the cutting of the work 21 progresses, the processing load per unit cutting length of the work 21 is kept constant.

The effects that can be expected from the above embodiment will be described below. (A) In the wire saw of this embodiment, when cutting the work 21, the processing load is detected by the processing load detector 44, and the control device 3 is controlled based on the detection result.
8, the processing load per unit cutting length of the work 21 is adjusted and controlled to be constant. Therefore, work 2
Even when the cutting length changes with the cutting process 1, the processing load hardly fluctuates, and the cutting process can be performed with a uniform load. Therefore, it is possible to prevent the thickness of the cut wafer and the surface roughness of the cut surface from being changed depending on the cut portion, and to improve the processing accuracy. In the initial light machining load condition,
The slurry is not excessively supplied, and the thermal deformation of the machine is suppressed.

(B) In the wire saw of the present embodiment, the processing load per unit cutting length of the work 21 is kept constant by adjusting the traveling speed of the wire 15 and the amount of slurry supplied by the control device 38. Is controlled.
For this reason, the processing load can be adjusted in response to a change in the cutting length during the cutting.

(C) In the wire saw of this embodiment, the machining load detector 44 uses the wire traveling motor 16
The processing load is detected by measuring the current or power to the device. For this reason, it is possible to accurately detect a change in the processing load during the cutting processing.

The embodiment of the present invention can be modified as follows. (1) Since the temperature of the slurry changes with the change in the processing load, the processing load is detected by measuring the temperature of the slurry, and the control is performed so that the processing load is constant. .

(2) The processing load is detected by measuring the current or electric power to the work lifting motor 22. That is, the reaction force acting on the work support mechanism 19, in other words, the upward force opposing the force for lowering the work 21 changes with the change in the processing load. Therefore, by detecting this variation, the processing load can be detected and the processing load can be controlled to be constant.

(3) The processing load is detected by detecting the current or power of the reel rotation motors 26 and 27. (4) The processing load is detected by the reel rotation motors 26, 2
7, wire running motor 16, slurry supply amount adjusting device 4
6. The operation is performed based on data obtained from one of the work lifting / lowering motors 22. Alternatively, it is performed based on data from a plurality of devices such as the reel rotation motors 26 and 27 and the slurry supply amount adjusting device 46.

[0034]

The present invention is configured as described above, and has the following effects. According to the first aspect of the present invention, even when the cutting length changes with the cutting of the work, the cutting can be performed without a change in the processing load. Therefore, it is possible to prevent the thickness of the cut wafer and the surface roughness of the cut surface from being changed depending on the cut portion, and to improve the processing accuracy. Further, in the light machining load state, the slurry is not excessively supplied, and the thermal deformation of the machine is suppressed.

According to the second aspect of the present invention, since the machining load is controlled to be constant by adjusting the slurry supply amount and the slurry supply angle, the cutting length during the cutting process is reduced. The processing load can be adjusted in response to the change.

According to the third aspect of the present invention, by measuring the current or power to the wire traveling motor,
Since the processing load is detected, it is possible to accurately detect a change in the processing load during cutting.

[Brief description of the drawings]

FIG. 1 is a front view showing a wire saw embodying the present invention.

FIG. 2 is a plan view of the wire saw.

FIG. 3 is a block diagram showing a control circuit of the wire saw.

FIG. 4 is a graph showing an adjustment state of a wire running speed and a slurry supply amount.

FIG. 5 is an explanatory diagram illustrating a cutting position of a workpiece by a wire.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Cutting mechanism, 13 ... Processing drive roller, 14 ... Processing driven roller, 13a, 14a ... Annular groove, 15 ... Wire, 16 ... Wire running motor, 19 ... Work support mechanism, 21 ... Work, 23 ... Reel Mechanism, 24 ... pay-out reel, 25 ... take-up reel, 26, 27 ... reel rotation motor, 34 ... slurry supply mechanism, 35 ... slurry supply pipe, 38 ... control device as control means, 39 ... CPU,
44: Processing load detector as detecting means, 49: Slurry supply amount adjusting device.

Claims (3)

[Claims] A wire is wound at a predetermined pitch between a plurality of processing rollers, and while the wire is running, a slurry is supplied onto the wire and the workpiece is brought into contact with the wire to cut the workpiece. A wire saw, comprising: detecting means for detecting a processing load when cutting the work; and control means for adjusting and controlling the supply of the slurry based on the detection result of the detecting means. 2. The method according to claim 1, wherein the control unit adjusts at least one of a traveling speed of the wire, a supply amount of the slurry, and a pressing force of the workpiece against the wire to keep a processing load per unit cutting length of the workpiece constant. The wire saw according to claim 1, wherein the wire saw is controlled in such a manner. 3. The wire saw according to claim 1, wherein the detecting means detects a processing load by measuring a current or an electric power to the wire traveling motor.