TWI417128B - Method and device for managing coolant of wire saw - Google Patents

Description

Cooling agent management method and device for wire saw

The present invention relates to a coolant management method and apparatus for a wire saw for cutting a tantalum material.

In the prior art, a device for cutting a tantalum material such as a twin ingot or a tantalum wafer is a so-called wire saw (see, for example, Patent Document 1). In the prior art, as shown in the patent document 1, the steel wire formed of the ferrous metal wire is moved while maintaining the specified tension, and the cutting fluid in which the abrasive grains have been dispersed in the dispersion (referred to as free) The abrasive grain method is supplied to the wire saw while the steel wire is brought into contact with the wire material, thereby cutting the contact portion in a line shape for cutting.

The cutting fluid used in the wire saw is obtained by mixing a large amount of abrasive grains having a weight ratio of, for example, 1:1 (that is, about 50%) in the dispersion to improve the machinability, and further, in order to perform uniformity. Cutting is required to improve dispersibility, so a relatively high viscosity dispersion is used.

In this case, when the cutting fluid having the high viscosity is supplied to the wire saw to cut the crucible material, the used slurry after the cutting is mixed with the above-mentioned high-concentration abrasive grains. The crumbs of the crucible after the material is cut, so that the concentration of the solid component is further increased, so the viscosity of the used slurry is increased.

The above-mentioned used slurry from the wire saw is usually taken into the recovery tank for storage after being taken into the slurry receiving tank. The used slurry stored in the slurry recovery tank is first supplied to the first separation means to separate the abrasive grains having a larger particle size than the swarf chips, and then sent to the second separation means to separate the swarf chips and the separation. liquid. The abrasive grains separated by the first separation means and the separation liquid separated by the second separation means are supplied to the stirring tank, and the unused agitating liquid or the unused dispersion liquid is supplied in the stirring tank. The cutting fluid is stirred, and the agitated cutting fluid is supplied to the wire saw. In the wire saw of the above-described free abrasive type, when the dispersibility of the abrasive grains in the cutting fluid is lowered, there is a problem that the wire saw cannot be uniformly cut. Therefore, it is necessary to carry out stirring for a long period of time to avoid precipitation and separation of the abrasive grains, thereby maintaining uniformity. Dispersion.

The used slurry from the above-mentioned wire saw has a very high viscosity as described above, and is mixed with abrasive grains and swarf chips. Therefore, it is necessary to provide a plurality of separation means for separating the abrasive grains and the swarf chips so that the separation operation is cumbersome and separate. The means are also relatively large and there is a problem of high equipment costs. As described above, the used slurry is difficult to separate, and therefore the separation of the previously used slurry is carried out in a batch mode after the completion of the cutting operation.

In addition, the swarf generated by the cutting operation reacts with water and additives in the dispersion to form a gelling action or a sol action, so that a blocky substance (clot) is formed in the cutting fluid. When it is desired to increase the traveling speed of the steel wire of the wire saw to perform the operation, the clot may bite on the steel wire, causing a problem that the quality of the cut surface of the tantalum material is lowered.

In addition, in the wire saw of the prior free-abrasive type, when the traveling speed of the steel wire is increased, there is a problem that the amount of abrasive grains substantially supplied to the cutting portion is reduced, and, as described above, the quality is lowered due to biting of the clot. The problem is that the traveling speed of the steel wire is previously lowered. Therefore, when the twin wire saw is cut by the previous wire saw, it takes a long time of about 12 to 24 hours, so that the cutting operation efficiency is low.

On the other hand, in recent years, a technique of cutting a silicon wafer by using a fixed abrasive grain steel wire (so-called fixed abrasive grain method) in which a diamond abrasive grain is fixed on a surface of a steel wire core material such as a piano wire is known (for example, refer to the patent document) 2, etc.). Patent Document 2 is a used slurry in which a coolant is supplied to a fixed abrasive steel wire and a crucible is cut, and the used swarf generated by the cutting is mixed, and is taken up by the slurry receiving groove and sent to the recovery. Slot storage. Then, the used slurry stored in the recovery tank is introduced into a sedimentation tank or the like to remove the swarf chips, and the coolant after removing the swarf swarf is introduced into the supply tank and then supplied to the fixed abrasive steel wire as a re-entry. use.

Since the fixed abrasive steel wire shown in Patent Document 2 has the diamond abrasive grains fixed on the steel wire, the dispersibility of the abrasive grains can be always ensured, so that the machinability can be improved in a shorter time than in Patent Document 1 described above. The cutting is completed, and as long as the coolant for cooling the main body is supplied to the fixed abrasive steel wire (no dispersibility is required), the advantage is that the coolant can be a low-viscosity and inexpensive product such as a water-soluble coolant.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-322066

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2002-144229

However, even when the crucible material is cut by using the fixed abrasive steel wire shown in Patent Document 2, the concentration of the solid component (the crumb) in the circulating coolant is maintained at a relatively high state, and According to the investigation by the inventors, when the cutting of the crucible material is started, the solid content concentration in the coolant at the end of the cutting is increased by 6 to 7%, so that the cutting speed of the fixed abrasive steel wire is lowered. The problem. In addition, during the storage of the used slurry in the recovery tank, the high concentration of the swarf swarf will react with the water and additives in the coolant to cause a gelation or sol to form agglomerates. Block) problem. Therefore, there is a problem in that the clot is bitten into the fixed abrasive grain line, and the quality of the cut surface of the tantalum material is lowered. Therefore, even if the fixed abrasive steel wire itself is excellent in machinability, the performance cannot be fully exerted. There is a problem of lowering the cutting speed.

The present invention has been made in view of the above problems, and provides a coolant management method and apparatus for a wire saw capable of greatly improving a cutting speed when a crucible material is cut by a fixed abrasive grain steel wire.

The coolant management method for a wire saw according to the present invention is a coolant management method for a wire saw for supplying a coolant to a fixed abrasive steel wire to which a diamond abrasive grain is fixed on a surface of a steel wire core material, and is characterized in that The used slurry obtained by cutting off is directly introduced into the centrifugal separator to remove the swarf chips, and the coolant after removing the swarf chips is supplied to the fixed abrasive grain steel wire for reuse.

In the above-described coolant management method for a wire saw, it is preferred that the used slurry is supplied to the centrifugal separator by gravity.

Further, in the coolant management method for the wire saw, the solid content concentration of the coolant after removing the chopped chips by the centrifugal separator is preferably 6 to 8% by weight.

Further, in the method for managing a coolant of the wire saw, it is preferred that the used slurry introduced into the centrifugal separator is heated.

A coolant management device for a wire saw according to the present invention has: a fixed abrasive grain steel wire provided by a wire saw body in which a diamond abrasive grain is fixed on a surface of a steel wire core material to cut a crucible material; and A coolant supply device for supplying a coolant to a fixed abrasive steel wire, comprising: a used slurry directly introduced into the wire saw body to remove swarf chips, and a coolant supply after removing swarf chips a centrifugal separator to the above coolant supply device.

In the coolant management device for the wire saw, a centrifugal separator is disposed below the wire saw body, and the used slurry from the wire saw body is preferably supplied to the centrifugal separator by gravity.

Further, in the coolant management device for the wire saw, it is preferable that a heater capable of heating the used slurry is provided at the inlet portion of the centrifugal separator.

According to the coolant management method and apparatus for a wire saw according to the present invention, the used slurry generated by the cutting can be directly introduced into the centrifugal separator, and the chopped chips in the used slurry can be immediately removed. The swarf concentration in the coolant returned to the coolant supply device as reused is managed in a stable low state, and therefore, the fixed abrasive grain steel wire can be kept at a high cutting speed, and, in addition, it is immediately removed and used. The swarf in the slurry can suppress the problem of gelation or sol action caused by the reaction of moisture and additives in the swarf and the coolant. Therefore, the problem of preventing the bite of the clot can be improved. The result of the quality of the cut surface of the crucible material is that it can achieve an excellent effect of increasing the cutting speed of the fixed abrasive grain steel wire.

In addition, since the separation performance of the centrifugal separator is adjusted so that the solid content concentration of the coolant after removing the chopped chips from the used slurry is 6 to 8% by weight, the quality of the cut surface can be maintained. The effect of raising the cutting speed of the fixed abrasive steel wire in a high quality state.

[Best Embodiment of the Invention]

Hereinafter, embodiments of the present invention will be described together with examples of the drawings.

Fig. 1 is a schematic block diagram showing an embodiment of a coolant management device for a wire saw according to the present invention. In Fig. 1, 1 is a wire saw body, and the wire saw body 1 has a fixed abrasive grain steel wire 2 to which a diamond abrasive grain is fixed on a surface of a steel wire core material, and is a plurality of times of hanging in a vertices downwardly arranged in an inverted triangular shape. The rollers 3a, 3b, 3c are driven to travel. Further, the upper portion of the fixed abrasive steel wire 2 hung between the rollers 3b and 3c is provided with the tantalum material 4 (workpiece), and the upper portion of the tantalum material 4 is provided so that the tantalum material 4 can be locked upward. The detached brake 5.6 is a coolant supply device 6 having: a supply tank 8 for housing the coolant 7; a coolant supply pipe 9 connected to the supply tank 8; and a coolant supply pipe provided therein The pump 10 and the cooler 11 of 9 are driven by the pump 10 to cause the coolant 7 of the supply tank 8 to be supplied to the wire saw body 1 through the supply nozzle 12 to be in contact with the fixed abrasive steel wire 2 Part.

Next, while driving the fixed abrasive grain steel wire 2, while the coolant supply device 6 supplies the coolant 7 to the portion where the crucible material 4 and the fixed abrasive grain steel wire 2 are in contact with each other, the inverted triangle is provided. When the shape of the rollers 3a, 3b, and 3c rises in the direction of the arrow A, the dam material 4 is cut by the fixed abrasive steel wire 2 in a state of being locked in the brake 5, and the cutting is completed in a plurality of portions.

The lower portion of the wire saw body 1 is a slurry receiving groove 14 for receiving the used slurry 13 which has fallen from the wire saw body 1, and is used in the slurry receiving groove 14 The slurry 13 is directly supplied from the slurry supply pipe 16 to the centrifugal separator 15 disposed on the lower side than the slurry receiving groove 14. That is, the used slurry 13 of the slurry receiving tank 14 is supplied to the centrifugal separator 15 by gravity. 17 is a warmer provided between the inlet of the centrifugal separator 15 and the slurry receiving tank 14. Further, in the illustrated example, the used slurry 13 showing the used slurry receiving tank 14 is supplied to the centrifugal separator 15 by gravity, but it may be supplied at the inlet of the centrifugal separator 15 as indicated by a broken line. With the pump 18, the used slurry 13 is supplied to the centrifugal separator 15 by the pump pressure.

As shown in FIG. 2, the centrifugal separator 15 is a cylindrical outer casing which is provided with a tapered portion 19 at one end side of a high speed rotation of, for example, 2000 to 6000 rpm, and is formed inside the cylindrical rotating body 19. The used slurry 13 is introduced through the inner shaft 22 provided inside the shaft 21 on the side of the tapered portion 19, and the inside of the rotating body 20 is provided with a slight rotation with the rotating body 20. The spiral 23 that rotates is poor, and therefore, the swarf chips of the used slurry 13 supplied from the inner shaft 22 inside the rotary body 20 are pushed by the centrifugal force toward the inner surface of the rotary body 20, and, in addition, the action of the spiral 23 is utilized. The left side of the second drawing is moved along the tapered portion 19 to form dehydration, and the dehydrated chopped chips 24 are discharged from the solid outlet 25. Further, the coolant 7 is sent to the right direction of the second drawing, and is taken out from the take-out port 27 of the side plate 26.

The chopping chips 24 discharged from the solids outlet 25 of the centrifugal separator 15 are collected in the chip collecting container 28 shown in Fig. 1, and the coolant 7 discharged from the outlet 27 of the centrifugal separator 15 is returned. The supply tank 8 to the coolant supply device 6 is used again. In the supply tank 8, a new coolant 7' is supplied as a supplement to reduce the amount of the coolant 7 due to evaporation, etc., and is supplemented with a component which is reduced in the centrifugal separator 15 due to the large component discharge together with the swarf chip 24. In order to adjust the composition.

The centrifugal separator 15 is a separation baffle that can be disposed inside the rotating body 20 to separate the chopping chips 24 and the coolant 7 in accordance with the supplied amount of the slurry 13 and the angle and length of the cone portion of the rotating body 20. The height can be adjusted to the removal performance of the chip 24, and the rotation speed of the rotating body 20 can be adjusted to adjust the removal performance of the chip 24, so that the solid content concentration in the coolant 7 after the chopping of the chopped chips can be adjusted to the target. value.

The inventors of the present invention performed the cutting test of the tantalum material 4 under the condition that the solid content concentration contained in the coolant 7 was adjusted to various values, and as a result, it was found that the solid content concentration of the coolant 7 was adjusted to 6 to 8 wt%. In this case, even if the cutting is performed while maintaining the high cutting speed, the high-quality cut surface of the crucible material 4 can be maintained. Further, the average particle diameter of the fixing component when the solid content concentration of the coolant 7 is 6 to 8% by weight is about 1 μm. Further, in order to improve the separation performance of the centrifugal separator 15 and maintain the solid content concentration of the coolant 7 at 6 to 8 wt%, it is known that the effective means is to supply the centrifugal separator 15 to the centrifugal separator 15 by means of the warmer 17. The used slurry 13 is heated.

Next, the operation of the above embodiment will be described.

While driving the fixed abrasive steel wire 2 of the wire saw body 1 to travel, the pump 10 is driven to supply the coolant 7 of the agitation supply tank 8 to the portion where the crucible material 4 and the fixed abrasive steel wire 2 are in contact, and the inverted triangle is made The shape of the rollers 3a, 3b, 3c rises in the direction of the arrow symbol A. As a result, the crucible material 4 stuck to the brake 5 is cut by the fixed abrasive steel wire 2 in a plurality of portions to complete the cutting.

The used slurry 13 produced by the cutting of the crucible material 4 is discharged to the slurry receiving groove 14, and the used slurry 13 of the slurry receiving groove 14 is supplied from the slurry supply pipe 16 to the centrifugal separator 15 to be immediately removed. Chips 24. The coolant 7 after the cutting of the chips 24 is supplied to the supply tank 8. At this time, the used slurry 13 is formed such that only the swarf chips 24 are mixed in the coolant 7, so that the viscosity is lower than that of the used granules in which the abrasive grains are previously mixed with the abrasive grains. With the centrifugal separator 15, it is possible to continuously and easily remove the swarf chips 24.

The supply tank 8 is supplied with a new coolant 7' as a supplement to reduce the amount of the coolant 7 due to evaporation or the like, and is supplemented with a decrease in the centrifugal separator 15 due to the large component being discharged together with the swarf chips 24. The composition, whereby the component adjustment, the component-adjusted coolant 7, is maintained at a specified temperature by the cooler 11 and then supplied to the wire saw body again.

As described above, since the used slurry 13 which is formed by cutting the tantalum material 4 is directly introduced into the centrifugal separator 15, the tantalum chips 24 in the used slurry 13 are immediately removed, so that the return to cooling can be performed. The agent supply device 6 manages the swarf concentration in the coolant 7 to be used in a stable low state, and therefore, the fixed abrasive steel wire 2 can be maintained at a high cutting speed. In addition, since the chopped chips in the used slurry 13 are removed immediately, it is possible to suppress the problem of gelation or sol action caused by the reaction between the chopped chips and the coolant and the additives in the coolant 7, and therefore, From the viewpoint of being able to prevent the problem of the bite of the clot, the quality of the cut surface of the crucible material 4 can be improved, that is, the cutting speed of the fixed abrasive grain 2 can be increased, that is, the cutting speed of the fixed abrasive steel wire can be improved.

Therefore, even if the coolant 7 obtained via the centrifugal separator 15 is returned to the coolant supply device 6 and re-supplied to the wire saw body 1 to cut the crucible material 4, the cut surface of the crucible material 4 can be maintained high. In the state of quality, the fixed abrasive grain steel wire 2 is used for high-speed cutting.

In the above, the number of rotations of the centrifugal separator 15 is controlled, and the solid content concentration of the coolant 7 after the removal of the chopping chips 24 is adjusted to 6 to 8 wt%. As described above, when the solid content concentration of the coolant 7 is adjusted to 6 to 8% by weight, the average particle diameter of the solid component is about 1 μm.

As described above, when the solid content concentration of the coolant 7 is adjusted to 6 to 8% by weight, the average particle diameter of the solid content at this time is about 1 μm, so that the influence of the solid content on the machinability is small, and therefore, the abrasive grains are fixed. The steel wire 2 can maintain a high cutting speed, and since there is almost no clot formation, the cut surface of the tantalum material 4 can maintain a high quality.

At this time, if the used slurry 13 to be supplied to the centrifugal separator 15 is heated by the warmer 17, the separation performance of the centrifugal separator 15 can be improved, so that the solidity of the coolant 7 can be made. It is easy to manage the concentration of the component to 6 to 8 wt%. Further, as described above, when the crucible material 4 is cut at a high speed by the fixed abrasive steel wire 2, the heat at the time of cutting causes the temperature of the used slurry 13 to rise, but it is used as the above temperature rises. Since the slurry 13 is directly introduced into the centrifugal separator 15, the separation performance of the centrifugal separator 15 can be improved by the heat.

Further, the method and apparatus for managing the coolant of the wire saw of the present invention are not limited to the above-described embodiments, and the method of cutting the material of the fixed abrasive steel wire of the steel wire body is not limited, and other examples are provided without departing from the invention. The scope of the subject matter is of course subject to various changes.

1. . . Wire saw body

2. . . Fixed abrasive steel wire

4. . .矽 material

6. . . Coolant supply device

7. . . Coolant

13. . . Used paste

15. . . Centrifugal separator

17. . . Warmer

twenty four. . .矽 矽

Fig. 1 is a schematic block diagram showing an embodiment of a coolant management device for a wire saw according to the present invention.

Fig. 2 is a schematic cross-sectional side view showing an example of a centrifugal separator.

1. . . Wire saw body

2. . . Fixed abrasive steel wire

3a, 3b, 3c. . . Wheel

4. . .矽 material

5. . . Brake

6. . . Coolant supply device

7. . . Coolant

7’. . . New coolant

8. . . Supply slot

9. . . Coolant supply tube

10. . . Pump

11. . . Cooler

12. . . Supply nozzle

13. . . Used paste

14. . . Slurry receiving groove

15. . . Centrifugal separator

16. . . Slurry supply tube

17. . . Warmer

18. . . Supply pump

20. . . Rotating body

twenty four. . .矽 矽

28. . . Chip recycling container

Claims (6)

A coolant management method for a wire saw, a coolant management method for a wire saw for supplying a coolant to a fixed abrasive grain steel wire with a diamond abrasive grain on a surface of a steel wire core material, characterized in that it is cut off The used used slurry is directly introduced into the centrifugal separator to remove the chopped chips, and the coolant after removing the chopped chips is supplied to the fixed abrasive steel wire for reuse, and is introduced into the centrifugal separator. The slip is heated. The coolant management method for a wire saw according to the first aspect of the invention, wherein the used slurry is supplied to a centrifugal separator by gravity. The coolant management method for a wire saw according to the first aspect of the invention, wherein the solid concentration of the coolant after removing the chopped chips by the centrifugal separator is 6 to 8% by weight. The coolant management method for a wire saw according to the second aspect of the invention, wherein the solid concentration of the coolant after removing the chopped chips by the centrifugal separator is 6 to 8% by weight. A coolant management device for a wire saw, comprising: a fixed abrasive steel wire provided by a wire saw body on which a diamond abrasive grain is fixed on a surface of a steel wire core material to cut a crucible material; and the fixed abrasive grain can be A coolant supply device for supplying a coolant to a steel wire, comprising: using a used slurry directly introduced into the wire saw body to remove swarf chips, and supplying the coolant after removing the swarf chips to the cooling a centrifugal separator of the agent supply device, and is provided at the inlet portion of the centrifugal separator The slurry is heated by a heater. The coolant management device for a wire saw according to claim 5, wherein a centrifugal separator is disposed in a lower portion of the wire saw body, and the used slurry from the wire saw body is supplied to the centrifugal by gravity. machine.