JP2000158340A - Operation control method of wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a cutting accuracy even in the cutting after the pause of a wire saw. SOLUTION: At the non-cutting time of a wire saw, as at least one standby operation is carried out, out of a standby operation for running a wire or a standby operation for circulating a processing liquid or a standby operation for regulating the temperature of the processing liquid, the deformation of a group roller can be prevented at the standby time of the wire saw, and the keeping state of the processing liquid can be maintained favorably and the next cutting accuracy can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire saw operation control method, and more particularly to a wire saw operation control method for performing a standby operation during non-cutting processing of a wire saw for cutting highly brittle materials such as silicon, glass and ceramics.

[0002]

2. Description of the Related Art When a wire saw is suspended for two hours or more between the end of a cutting process and the removal of a workpiece, a pause date is inserted before the next cutting process is started, or the setup of the next cutting process is performed. If the wire saw is suspended for 2 hours or more for reasons such as a shift of an operator before starting the operation, the operation of the wire saw in the wire saw, the circulation of the working fluid, the temperature control of the working fluid, etc. is stopped. Was.

[0003]

However, when the wire saw is paused for two hours or more before the workpiece is removed after the completion of the cutting process as in the prior art, or when the wire saw is stopped until the next cutting process is started. If there is a pause time longer than the time, the wire wound portion of the groove roller whose surface is covered with resin is deformed by the tension of the wire during the pause time, and the tension of the wire row at the next cutting There has been a problem that the cutting accuracy is degraded due to fluctuations or runaway of a running wire. In addition, the processing fluid containing abrasive grains solidifies or solids settled throughout the processing fluid storage tank, the inside of the heat exchanger, and the flow path of the processing fluid including the pump, and the processing fluid becomes a predetermined amount. If the flow rate does not flow, or the working fluid cannot exhibit the predetermined ability, there has been a problem that the cutting accuracy is deteriorated at the next cutting.

The present invention has been made in view of the above circumstances, and prevents the groove roller from being deformed when the wire saw is on standby, and maintains the state of preservation of the working fluid in a good state, thereby improving the accuracy of the next cutting operation. The purpose is to maintain.

[0005]

According to the present invention, in order to achieve the above object, a wire is wound around a plurality of groove rollers to form a wire array, and the wire is run and a machining fluid is applied to the wire array. In a wire saw that cuts a large number of wafers by pressing a workpiece while supplying it, a standby operation of running a wire, a standby operation of circulating a processing liquid, or a standby state of adjusting the temperature of the processing liquid during non-cutting processing It is characterized in that at least one standby operation is performed among the operations.

According to the present invention, since the wire saw performs the standby operation during the non-cutting operation, the state of the apparatus can be maintained until the next cutting operation, so that the processing accuracy can be maintained.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a wire saw operation control method according to the present invention. FIG. 1 is a perspective view showing the overall configuration of a wire saw to which the control method of the present invention is applied.

As shown in FIG. 1, a wire 14 wound around a wire reel 12 has a large number of guide rollers 16, 16,
Are wound around three groove rollers 18A, 18B and 18C via a wire running path formed by... To form a parallel wire row 20. Wire 1 on which wire row 20 is formed
The wire 4 is wound around a wire reel (not shown) through a wire running path on the other side formed symmetrically with respect to the wire row 20.

Guide rollers 16, 16,..., A wire guide device 22, a dancer roller 24, and a wire cleaning device 26 are provided on the wire running paths formed on both sides of the wire row 20 (only one side is shown). ), The wire guiding device 22 guides the wire 14 from the wire reel 12 at a constant pitch. The dancer roller 24 is provided with a weight (not shown) having a predetermined weight, and applies a constant tension to the traveling wire 14 with the weight. The wire cleaning device 26 sprays a cleaning liquid onto the running wire 14 and removes the processing liquid attached to the wire 14 from the wire 14.

FIG. 2 is a diagram showing an embodiment of a control system of each motor and a circulation system of cooling water according to the present invention. Forward and reverse rotatable reel motors 13M and 13M (only one side is shown) are connected to the pair of wire reels 12 and 12 (only one side is shown), and forward and reverse rotatable motor 19M is connected to the groove roller 18C. The wire 14 is driven by these motors to form a pair of wire reels 12,
It runs back and forth between 12 at high speed. These reel motors 13
The rotation speeds of the motors M and 13M and the motor 19M are controlled according to a command from the control means 50. Since these motors have large outputs, they are cooled by cooling water 56.

The reel motors 13M, 13M have rotation detecting means 13 for detecting the rotation speed of the motor rotating shaft.
G, 13G. A rotation detecting means 19 for detecting the rotation speed of the motor rotation shaft is provided on the motor 19M.
G is provided. The detected rotation speeds of the respective motors are sent to the control means 50 and used for controlling the rotations of the respective motors.

Above the wire row 20, a wire row 2
A work feed table 28 that moves vertically with respect to 0 is installed. The work feed table 28 is provided with a holding unit 30, and the ingot 32 is held at a lower portion of the holding unit 30 with the crystal orientation aligned.
A forward / reverse rotatable motor 29M is connected to the work feed table 28 via a power transmission mechanism. The work feed table 28 is a power transmission for converting the forward / reverse rotation of the motor 29M into vertical movement. It moves up and down by a mechanism. The motor 29M is provided with rotation detection means 29G for detecting the rotation speed of the motor rotation shaft.
0 is used to control the motor 29M. The motor 29M is a motor 19M or a reel motor 13M.
In the embodiment shown in FIG. 2, the motor 29M is not forcibly cooled by the cooling water 56 because the amount of heat generation is smaller than that of the motor 29M.

As shown in FIG. 2, a pair of working fluid nozzles 42 are provided above the wire row 20.
The pair of machining fluid nozzles 42, 42 are located near the groove rollers 18A, 18B, respectively.
A and 18B are installed coaxially. A processing fluid storage tank 34 is provided below the wire saw 10 and stores a processing fluid therein. The working fluid in the working fluid storage tank 34 is pumped up by a supply pump 44, supplied to working fluid nozzles 42, 42 installed above the wire row 20, and ejected from the working fluid nozzles 42, 42 to the wire row 20. You. An oil pan 36 is provided below the wire row 20, and collects the working fluid injected to the wire row 20 and sends it to the working fluid storage tank 34.

The working fluid nozzles 42, 42 have slits (supply ports) formed in the lower surface thereof in a slit shape, and uniformly eject the working fluid supplied to the working fluid nozzles 42, 42 over the entire width of the wire row 20. It is formed so that. Further, a flow controller (not shown) for adjusting the flow rate of the processing liquid is provided in a flow path connecting the processing liquid storage tank 34 to the processing liquid nozzles 42, 42, and the flow rate of the processing liquid ejected to the wire row 20 is provided. The flow rate is controlled by the control means 50 so that the flow rate becomes an optimum flow rate, and the processing liquid necessary for cutting the ingot 32 is sufficiently attached to the wire row 20.

Since the temperature of the working fluid rises due to the working heat during the cutting work, the wire saw 10 is provided with a heat exchanger 38 for adjusting the temperature of the working fluid. The working fluid in the working fluid storage tank 34 is
The work fluid is circulated and supplied by the heat exchange pump 46 for heat exchange. Since the working fluid is a solution containing abrasive grains, it is constantly stirred to prevent precipitation. The stirring device is installed in the working fluid storage tank 34, and a stirring blade (not shown) is connected to a rotating shaft of a stirring motor (not shown), and the working fluid is uniformly stirred by rotating the stirring blade. The processing liquid and components having different specific gravities such as abrasive grains contained in the processing liquid are uniformly dispersed.

In the wire saw 10, in order to cool each heat-generating portion, a cooling water 56 is supplied in accordance with a command from the control means 50 to exchange heat and cool each heat-generating portion. An input unit 52 for inputting each condition is displayed on the control unit 50, and an input value from the input unit 52 is displayed.
Display means 54 for displaying the operation status of the wire saw 10 is connected.

The parts that need to be cooled by heat generation are the motors 19M and 19M that are the power sources of the reel motors 13M and 13M groove rollers 18A to 18C, the supply pump 44, the heat exchange pump 46, the heat exchanger 38, and the groove rollers 18A.
~ 18C bearing. The cooling water 56 passes through the cooling water supply passage 58 to cool the respective parts, and then the cooling water discharge passage 6
0 to the outside of the wire saw.

A valve which can be independently controlled by a command from the control means 50 is provided near each cooling portion. A reel motor cooling valve 62 is provided in the coolant supply passage 58 of the reel motors 13M, 13M, a motor cooling valve 64 is provided near the motor 19M, and a pump cooling valve 65 is provided near the supply pump 44 and the heat exchange pump 46. 66, a heat exchanger cooling valve 68 near the heat exchanger 38, and groove rollers 18A to
A bearing cooling valve 70 is provided near each of the 18C bearings.

At the time of cutting, each cooling valve is opened according to a command from the control means 50 to start cooling, and the reel motor 13 is controlled according to a command from the control means 50.
M, 13M and motor 19M to drive the wire reel 1.
2 and the groove rollers 18A to 18C are rotated at a high speed,
The wire 14 is reciprocated at a high speed. Then, the work feed table 28 is lowered and the ingot 32 is pressed against the wire array 20 while ejecting the machining fluid from the injection port of the machining fluid nozzle 42 to the traveling wire array 20. Then, the ingot 32 is cut into a large number of wafers by the lapping action of the abrasive grains contained in the processing liquid.

When the cutting is completed and the workpiece is removed, or after the cutting is completed and the workpiece is removed, if the cutting is not performed by the wire saw for more than 2 hours, and the machine is stopped, The operation is performed by setting the wire saw to a preset standby operation mode. The following describes an example of an operation method for setting the conditions of the standby operation mode and activating the standby operation.

FIG. 3 shows a setting menu screen of the automatic operation mode of the wire saw 10 displayed on the display means 54. The operation mode items of the wire saw 10 are displayed side by side on the menu screen. After the message line 72 is moved by pressing a cursor key provided on the input unit 52, the message mode is provided on the input unit 52. Press the ENTER key to select the required operation mode. Here, an example in which the mode of “10. standby operation function selection setting” is selected will be described below.

FIG. 4 shows a menu screen for selecting and setting the standby operation function of the wire saw 10 displayed on the display means 54. On the menu screen, items to be operated during the standby operation are displayed side by side. When a cursor key provided on the input means 52 is pressed, a message line 7 is displayed.
After moving 2, the number of 1 or 0 is input to enable / disable each function. Whether the prepared function is valid or invalid can be confirmed by the operator by displaying <valid> or <invalid> on the display line of the functioning item. In the state of this screen, the input means 52
By pressing the START key provided in the system, the standby operation which continues to operate until the next disconnection is started, and when the ESC key is pressed in the state of this screen, the standby operation is not started and the screen returns to the previous screen shown in FIG.

The standby operation (operation holding function) from the end of the cutting process to the removal of the workpiece is usually performed as follows.
Before the cutting process is completed, wait for the operation
The operator inputs “valid” or “invalid” using the input means 52 in advance. Then, the wire saw 10 automatically enters the standby operation mode (operation holding function) immediately after the completion of the cutting processing without bothering the operator.

The operation holding function is to remove the workpiece immediately due to lack of workers, for example, when the cutting of the workpiece is completed at a plurality of wire saws at a time when the number of workers at midnight is small, and the next workpiece is removed. It is convenient to keep the operation of the wire saw for a period of time until the daytime personnel removes the workpiece after cutting, when there is a possibility that preparation for cutting may not be possible. .

FIG. 5 shows a display example of a screen for setting operating conditions during standby operation. This setting screen is the screen that is displayed next when the mode of “9. Standby operation condition setting” in FIG. 3 is selected. In the standby operation condition setting screen shown in FIG. 5, the message line 72 is moved by the cursor keys provided on the input means 52 in the same manner as the operation method on the previous screen, so that wire running, machining fluid circulation, machining fluid temperature are performed. The operating conditions during the standby operation can be set by selecting each condition such as adjustment and supply of a working fluid and inputting a numerical value.

Operating under the conditions set as described above,
An embodiment of the standby operation according to the present invention will be described below with reference to the drawings. FIG. 6 is a diagram showing the relationship between time and wire traveling speed during the cutting operation and the standby operation. According to the figure, the wire 14 is traveling reciprocally, and the wire traveling speed is set to be much lower in the standby operation than in the cutting operation, and the wire 14 is traveling.

FIG. 7 is a diagram showing another embodiment of the method of traveling the wire 14 during standby operation. This figure shows the relationship between time and wire traveling speed. In the example of the traveling method of the wire 14 shown in FIG. 6, the wire 14 reciprocates, but in the example of the traveling method of the wire 14 shown in FIG. This shows a situation where the vehicle is traveling at a low traveling speed only in one direction.

FIGS. 8A to 8D show an embodiment of a control method when the working fluid temperature control function during standby operation is enabled. FIG. 8A shows time t on the horizontal axis.
The vertical axis indicates the measured temperature (° C.) of the working fluid, and shows how the temperature of the working fluid is adjusted. FIG. 8B shows the time t.
The horizontal axis indicates the temperature control circulating flow rate (l / min) of the machining fluid, and the vertical axis indicates the temperature control circulating flow rate controlled according to the machining fluid temperature in FIG. According to FIG. 8, when the measured value of the working fluid temperature rises in FIG. 8A, the flow rate of the working fluid circulating through the temperature controller is increased to improve the cooling property of the working fluid, and the working fluid temperature is reduced. The figure shows a state in which control is performed so as to decrease to a set temperature. Then, when the measured temperature of the working fluid becomes equal to or lower than the set temperature, the temperature control circulation flow rate is set to 0 and cooling is stopped. The means for controlling the temperature control circulation flow rate may control the flow rate of the machining fluid discharged from the heat exchange pump 46 by changing the rotation speed of the motor of the heat exchange pump 46, A valve for controlling the flow rate may be provided in the middle of the flow path with the storage tank 34 to control the flow rate of the processing liquid.

FIG. 8C shows how the temperature of the working fluid is controlled by plotting the electric power (W) supplied to the heater for warming the working fluid on the vertical axis with time t on the horizontal axis. FIG.
(B) shows the temperature control circulating flow rate which is a control means for lowering the temperature of the working fluid, whereas FIG. 3 (B) shows that the temperature of the working fluid increases when the temperature of the working fluid is lower than the set temperature. The figure shows the amount of power supplied to the heater, which is a control means for causing the heater to operate. In FIG. 8A, when the measured temperature of the working fluid is lower than the set temperature, the power supplied to the heater is increased to warm the working fluid, and the temperature of the working fluid is increased to approach the set temperature. Control.

FIG. 8 (D) shows how the heat exchanger cooling water valve for controlling the flow of the cooling water supplied to the heat exchanger is opened and closed with time t as the horizontal axis. In the example shown in the figure, the heat exchanger cooling water valve of the cooling water supplied to the heat exchanger is always open while the wire saw is cutting. This is because the temperature of the machining fluid tends to increase due to the machining heat during cutting, and the rate of time for cooling the machining fluid is longer than the rate of time for heating the machining fluid. The water valve is left open to supply cooling water to the heat exchanger,
The heat exchanger cooling water valve may be controlled according to the temperature control circulation flow rate.

FIGS. 9A to 9C show an embodiment of a control method according to the present invention when the working fluid temperature control function during the standby operation is disabled. In the case of standby operation (operation holding function) between the end of cutting and the removal of the workpiece, there is a high possibility that the used working fluid will be replaced later. As shown in FIG. 9, a circulating process in which the working fluid temperature control function is disabled is often used.

FIG. 9 (A) shows the temperature control circulating flow rate (l / min) of the working fluid on the vertical axis with time t as the horizontal axis, and a predetermined circulation cycle O at every predetermined circulation cycle OFF time Tn1.
An operation for circulating the machining fluid for N hours Tn2 to prevent the machining fluid from solidifying in the heat exchanger and the circulation path of the machining fluid and preventing problems such as settling of abrasive grains. Is shown. A predetermined circulation cycle O in FIG.
The temperature control circulating flow rate of the working fluid circulating during the FF time Tn1 and the temperature control circulating flow rate of the working fluid circulating during the predetermined circulating cycle ON time Tn2 are the pump rotations shown in FIG. Number (number of rotations of pump 46 shown in FIG. 2)
The flow rate can be varied by changing.

In FIG. 9B, the electric power (W) supplied to the heater for heating the working fluid is plotted on the ordinate, with time t as the abscissa. According to the drawing, since the temperature of the working fluid is not adjusted, power is not supplied to the heater during the standby operation. FIG. 9C shows how the heat exchanger cooling water valve 68 for controlling the flow of the cooling water supplied to the heat exchanger is opened and closed with time t as the horizontal axis. In the example shown in the figure, since it is not necessary to control the temperature of the working fluid, the heat exchanger cooling water valve 68 of the cooling water 56 always supplied to the heat exchanger 38 is closed while the wire saw 10 is in the standby operation. , The supply of the cooling water 56 is shut off. Therefore, useless consumption of the cooling water 56 can be prevented.

FIG. 10 shows an embodiment of a control method according to the present invention when the machining fluid supply function during standby operation is enabled. In FIG. 10, the time t is set on the horizontal axis, and the supply flow rate of the working fluid (l / min) is set on the vertical axis, and the predetermined supply cycle Hi time Tj is set for each predetermined supply cycle Lo time Tj1.
A state in which a predetermined amount of the working fluid is supplied for each of two times to prevent the working fluid from being solidified in the working fluid nozzle or the working fluid supply path, or the occurrence of problems such as settling of abrasive grains. Is shown. A supply flow rate of the machining fluid supplied during a predetermined supply cycle Lo time Tj1 in FIG.
The supply flow rate of the machining fluid supplied during the predetermined supply cycle Hi time Tj2 is obtained by changing the pump rotation speed (the rotation speed of the pump 44 shown in FIG. 2) in the item of the machining fluid supply shown in FIG. The flow rate can be changed. By finely controlling the flow rate of the processing liquid to be supplied in this manner, an efficient standby operation can be performed.

[0035]

As described above, according to the present invention,
Since the wire saw performs a standby operation at the time of non-cutting processing, deformation of the groove roller can be prevented, and the preservation state of the processing liquid can be maintained in a good state, thereby maintaining the accuracy of the next cutting processing. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a wire saw to which an embodiment of a control method according to the present invention is applied.

FIG. 2 is a diagram showing an embodiment of a control system of each motor and a circulation system of cooling water according to the present invention.

FIG. 3 is a diagram showing a setting menu screen of a wire saw automatic operation mode displayed on a display means.

FIG. 4 is a diagram showing a menu screen for selecting and setting a standby operation function of the wire saw displayed on the display means.

FIG. 5 is a view showing a screen for setting operating conditions during standby operation of the wire saw displayed on the display means.

FIG. 6 shows the time during the cutting operation and the standby operation;
Diagram showing relationship with wire running speed

FIG. 7 is a diagram showing another embodiment of a method of traveling a wire during standby operation.

FIG. 8A is a diagram illustrating an embodiment of a control method when a machining fluid temperature control function is enabled during a standby operation. FIG. 8A shows a measured temperature (° C.) of machining fluid with time t as a horizontal axis. FIG. 8 (B) shows how the temperature of the working fluid is adjusted on the vertical axis, and FIG. 8 (A) shows the temperature control circulating flow rate (l / min) of the working fluid on the vertical axis with time t as the horizontal axis. (C) showing a state in which the temperature control circulating flow rate is controlled in accordance with the temperature of the processing fluid of FIG. FIG. 4D shows how the temperature of the liquid is controlled. FIG. 4D shows how the heat exchanger cooling water valve for controlling the flow of the cooling water supplied to the heat exchanger is opened and closed with time t as the horizontal axis. Figure

FIG. 9 is a diagram showing an embodiment of a control method according to the present invention when the working fluid temperature control function during the standby operation is invalidated. FIG. The vertical axis indicates the flow rate (l / min) and the state of the temperature control circulation during the standby operation. (B) indicates the power (W) supplied to the heater for warming the working fluid with the time t as the horizontal axis. FIG. 2C shows the state of heating of the working fluid, and FIG. 2C shows the opening and closing of a heat exchanger cooling water valve that controls the flow of cooling water supplied to the heat exchanger with time t as the horizontal axis.

FIG. 10 is a diagram showing an embodiment of a control method when a machining fluid supply function is enabled during a standby operation according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wire saw 12 ... Wire reel 13M ... Reel motor 14 ... Wire 16 ... Guide roller 18A-18C ... Groove roller 19M ... Motor 32 ... Ingot 38 ... Heat exchanger 44 ... Supply pump 46 ... Heat exchange pump 50 ... Control means 56 ... Cooling water

Continued on the front page F term (reference) 3C047 FF06 FF09 GG13 GG15 GG20 3C058 AA05 AA07 AA11 AA18 AC01 AC04 BA04 BA08 BC02 BC03 CA01 CA04 CA05 CA06 DA03 3C069 AA01 BA06 BB03 BC01 CA04 DA06 EA02 EA03

Claims (2)

[Claims] A wire is wound around a plurality of groove rollers to form a wire row, and the wire is run and cut into a large number of wafers by pressing a workpiece while supplying a working liquid to the wire row. In a wire saw to be processed, at least one of a standby operation of running a wire, a standby operation of circulating a processing fluid, and a standby operation of adjusting a temperature of a processing liquid is performed during non-cutting processing. An operation control method for a wire saw. 2. A wire is wound around a plurality of groove rollers to form a wire array, and the wire is run and cut into a large number of wafers by pressing a workpiece while supplying a working liquid to the wire array. For the wire saw to be processed, an operation holding function that automatically continues the running of the wire after the end of the cutting process, an operation holding function that continues the circulation of the working fluid, or an operation holding function that continuously adjusts the temperature of the working fluid An operation control method for a wire saw, wherein at least one operation holding function is provided.