JP3222784B2 - Wire saw slurry management system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Field of the Invention The present invention relates to a slurry management system of the wire saw.

[0002]

2. Description of the Related Art Conventionally, when a wafer is made from a highly brittle material such as ceramic, an IC chip substrate, silicon for a solar cell, and synthetic quartz, a processing apparatus called an inner saw is employed. However, since this device cuts highly brittle materials one by one with a cutting blade to make a wafer,
Obtaining a large number of wafers is very time consuming and results in poor production efficiency. In addition, there is a problem that the yield is low due to the large amount of kerf loss (the portion that is cut off from the object to be cut during cutting).

Therefore, recently, a device called a wire saw has been developed and is being implemented. For example, as shown in FIG. 8, one wire is connected to three processing rollers 1.
The wire group 11 includes a wire group 11 extending in parallel between the wires 2a, 12b, and 12c at a predetermined pitch, and a slurry supply pipe 13 that supplies slurry to the wire group 11. Further, the apparatus includes a receiving tank 14 provided in a processing region formed by the wire group 11 and a slurry tank 15 provided on the downstream side of the receiving tank 14. The slurry supply pipe 13 and the slurry tank 15 are connected by a supply pipe 16 provided with a valve V1 and a pump P1 on the way. Further, the slurry tank 15 is provided with a slurry supply port 15a and a slurry discharge pipe 17 having a valve V2.
Is connected.

When cutting the object 18 with such an apparatus, the valve V2 is closed and the valve V1 is opened, and a slurry obtained by dispersing abrasive grains in a water-based or oil-based dispersion liquid is supplied to a slurry tank. Slurry supply pipe 1 from 15
3 circulates and supplies to the wire group 11. At the same time, the rollers 12a, 12b, and 12c are rotated, for example, clockwise in the figure to move the wire group 11 rightward.
The object to be cut 1 arranged above the wire group 11
By lowering 8 and passing it below the wire group 11, the object to be cut 18 is cut by the wire group 11, and a large number of wafers are obtained at the same time.

[0005] The cutting ability of the wire group 11 greatly depends on the mixing weight ratio of the abrasive and the dispersion in the slurry supplied to the wire group 11. For this reason, in order to efficiently cut the workpiece 18, the mixing weight ratio between the abrasive grains and the dispersion liquid in the slurry is maintained at a value such that the wire group 11 can maximize the cutting ability. There is a need to.

[0006] In the above cutting process, the slurry supplied from the slurry supply pipe 13 to the wire group 11 is
It is stored in the slurry tank 15 via the receiving tank 14. Each time the cutting process is completed a predetermined number of times, the slurry tank 1
5 is discharged from the slurry supply port 15a.
The slurry is supplied to the slurry tank 15 through the above, and the slurry is regenerated.

The reason for replacing a part of the slurry in this way is that, when the object to be cut 18 is cut, chips of the object to be cut 18 are mixed into the slurry, and the amount of the chips is increased. Because the amount of abrasive grains usable for cutting is reduced due to the crushing of the abrasive grains at the time of cutting,
This is because the cutting efficiency decreases. However, even if a part of the slurry is regularly replaced, the amount of chips and crushed abrasive grains in the slurry gradually increases. I try to replace it with new slurry.

[0008]

However, as described above, in the conventional apparatus, even if a part of the slurry is periodically replaced, the amount of chips and crushed abrasive particles in the slurry gradually increases. Therefore, the mixing weight ratio between the abrasive grains and the dispersion in the slurry cannot always be maintained at an optimum value. For this reason, the cutting ability of the wire group 11 gradually decreases, and the cutting efficiency decreases.

Further, in the conventional apparatus, when the slurry is exchanged, the slurry discharged from the slurry tank 15 is
It is disposed of as waste slurry. This waste slurry contains usable abrasive grains and dispersion liquid, and discarding it and supplying new abrasive grains and dispersion liquid increases the consumption of abrasive grains and dispersion liquid required for the cutting process. As a result, there is a problem that the cost of the cutting process increases. Further, since the dispersion is disposed of as industrial waste, there is a problem that the load of processing the amount of industrial waste increases.

Further, in the above-mentioned conventional apparatus, when performing the slurry exchange processing, the abrasive grains and the dispersion liquid are charged into the slurry tank 15 and mixed to adjust the slurry. It took time. In addition, since the amount of slurry required for cutting is insufficient during the replacement process, the cutting process of the object to be cut 18 is stopped, and particularly when the entire amount of the slurry is replaced, a very long time is required. Because it takes
There was a problem that work efficiency was poor.

The present invention has been made to cope with such a situation. Its main purpose is to provide a slurry management <br/> system of the wire saw can be formulated a slurry mixing weight ratio of the abrasive grains and the dispersion liquid is set to a suitable value for cutting.

Another object of the present invention is to provide a wire saw slurry management system capable of reusing abrasive grains and a dispersion and reducing the cost of cutting.

Another object of the present invention is to provide a wire saw slurry management system capable of continuously supplying slurry to the wire saw and improving the working efficiency.

[0014]

To achieve the above object, according to the Invention The, <br/> Oite slurried management system of the wire saw of this invention is constructed as described in the following claims It was done.

According to the first aspect of the present invention, a slurry obtained by dispersing abrasive grains in an oil-based dispersion liquid is supplied to a group of wires stretched in parallel with each other, and the object to be cut is connected to the group of wires. by passing, in the slurry management system for wire saw to obtain a large number of wafers simultaneously, the supplying abrasive grains and dispersion blending tank Sula
Blending means for blending leeches , first separating and collecting means for separating and removing fine-grained components and dispersions finer than abrasive grains from the slurry discharged from the wire saw , and collecting reusable abrasive grains. A second separation / recovery means for separating and removing the fine particle component from the dispersion liquid containing the fine particle component separated and removed by the first separation / recovery means, and recovering the dispersion liquid; and the first and second separation / recovery means Abrasives collected by means
Transporting the liquid and the dispersion liquid on the way and transporting them to the mixing tank
Means, wherein the compounding means includes the first and second components.
Reuse abrasive particles and dispersion recovered by separation and recovery means
And mix the slurry to be supplied to the wire saw.
And features.

A slurry management system according to claim 2
In the first aspect, in the mixing means, abrasive grains and
The mixing weight ratio with the il-based dispersion is from 1: 0.91 to 1:
A slurry with a range of 0.6 is prepared. Claim 3
In the slurry management system described above,
And a slurry having a viscosity of 150 to 220 cp is prepared.
You.

In the slurry management system according to the present invention, a slurry obtained by dispersing abrasive grains in an aqueous dispersion is supplied to a group of wires stretched in parallel with each other, and the object to be cut is supplied to the group of wires. In a slurry management system for a wire saw that allows a large number of wafers to be obtained at the same time by passing the same , abrasive grains and a dispersion are supplied to a mixing tank and
Dispensing means for dispensing a slurry, first separating and collecting means for separating and removing fine particles and dispersions finer than abrasive grains from the slurry discharged from the wire saw , and collecting reusable abrasive grains; A second separation / recovery means for separating and removing the fine particle component from the dispersion liquid containing the fine particle component separated and removed by the first separation / recovery means, and recovering the dispersion liquid; and the first and second separation / recovery means Collected by means
Abrasive grains and dispersion liquid are merged on the way and transported to the mixing tank
Transport means, wherein the blending means comprises the first and second
The abrasive particles and the dispersion recovered by the separation and recovery means 2
Reuse and mix slurry to be supplied to the wire saw
It is characterized by doing.

[0018] In the slurry management system according to claim 5,
In claim 4, in the mixing means, abrasive grains and water
The mixing weight ratio with the dispersion of the system is from 1: 0.76 to 1: 0.
A slurry in the range of 5 is prepared. Claim 6
The slurry management system according to claim 4 or 5,
Thus, a slurry having a viscosity of 40 to 50 cp is prepared.

A slurry management system according to claim 7
Is for the wire group according to any one of claims 1 to 6,
The average particle size suitable for cutting with a wire saw is 5 to 30.
A μm of new abrasive is supplied.

[0020] In the slurry management system according to the eighth aspect, the first pipe as a transport means for transporting the abrasive grains recovered by the first separation and recovery means to the mixing tank according to the first or fourth aspect. Is connected to the blending tank , and a second pipe serving as a transporting unit for transporting the dispersion liquid collected by the second separation and collecting unit to the blending tank is a first pipe upstream of the blending tank. Merging with the piping. In the slurry management system according to the ninth aspect, in claim 1 or 4, the average grain size of the abrasive grains reused when preparing the slurry is 5 to 30 μm.

[0021] A slurry management system according to claim 10.
Then, in claim 1 or 4, the first separation and recovery means
The centrifugal separation in
The abrasive grains are separated from the rally.

In the slurry management system according to the eleventh aspect, in the first or fourth aspect, the dispersion liquid is separated from the slurry discharged from the wire saw by centrifugal separation in the second separation and recovery means.

According to a twelfth aspect of the present invention, in the first or fourth aspect, the abrasive grains and the dispersion liquid are separated from the slurry discharged from the wire saw by centrifugal separation in the first and second separation and recovery means. You.

A slurry management system according to claim 13
Then, one of the abrasive grains according to any one of claims 10 to 12,
The next separation and recovery is suitably performed.

In the slurry management system according to the fourteenth aspect, in any one of the tenth to thirteenth aspects, the secondary separation and recovery of the dispersion liquid is performed at a high acceleration. In the slurry management system according to claim 15, in any one of claims 10 to 14, at least one of the first and second separation and recovery means includes a screw conveyor provided inside the case and the screw conveyor. And an inner cylinder rotatably provided in the case so as to surround the inner cylinder. In the slurry management system according to the sixteenth aspect, in any one of the first to sixth aspects, the mixing weight ratio of the abrasive and the dispersion in the slurry prepared by the preparation means or the viscosity of the slurry is set to a set value. Then, the supply amount of the abrasive and the dispersion is adjusted and controlled by the control means. Claim 17
In the slurry management system of the present invention, the abrasive content in the slurry prepared by the mixing means is detected by the abrasive content detecting unit. Then, based on the detection result of the abrasive grain content detection section, the controller controls the abrasive grain supply amount adjustment section and the dispersion liquid supply amount adjustment section, and adjusts the supply amounts of the abrasive grains and the dispersion liquid. Claim 18
In the slurry management system described in Item 17, the abrasive content detection unit detects the abrasive content in the slurry by measuring at least one of the specific gravity and the viscosity of the slurry.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, the blending tank 2 constitutes a blending means for blending a slurry, and a stirrer 20 is provided in the inside thereof. In this mixing tank 2, a hopper 21 and a screw feeder 21a serving as an abrasive grain supply unit for supplying abrasive grains to the inside thereof are connected via a pipe T21 provided with a valve V21 serving as an abrasive grain supply amount adjusting unit. It is connected. In addition, the mixing tank 2 includes an oil tank 22 serving as a dispersion liquid supply unit for supplying a dispersion liquid such as a base oil therein, and a pipe T22 provided with a valve V22 and a pump P22 serving as a dispersion liquid supply amount adjustment unit. Connected through.

Further, in the mixing tank 2, a hydrometer S1 serving as a specific gravity detector for measuring the specific gravity of the slurry, and a viscometer S serving as a viscosity detector for measuring the viscosity of the slurry are provided.
2 are provided. The specific gravity meter S1 and the viscometer S2 constitute a means for detecting the abrasive content of the slurry. Based on these detected values, the valve V2 is controlled by a command signal from a controller C1 constituting a control means.
1, the opening degree of V22 is controlled.

A slurry storage tank 3 for storing the prepared slurry is connected to the downstream side of the mixing tank 2 via a pipe T2, and a stirrer 30 is disposed inside the slurry storage tank 3.
Further, on the downstream side of the slurry storage tank 3, for example, each slurry tank 45 of four wire saws W1 to W4 is provided with pipes T3, T3.
1 to T34. In FIG. 1, V2, V3, and V31 to V34 denote valves, and P3 denotes a pump.

Each of the wire saws W1 to W4 has the same structure. The first wire saw W1 will be representatively described with reference to FIGS. In the drawing, reference numeral 41 denotes a wire made of one piano wire, which is continuously wound spirally at a predetermined pitch between three processing rollers 42a, 42b, and 42c forming a triangular region, and stretched in parallel with each other. It is a wire group provided. The object to be cut 46 is, for example, two rollers 42.
The wire group 41 is disposed above the horizontal plane of the wire group 41 formed between a and 42b, and is lowered so as to pass through the wire group 41.

A slurry supply pipe 43 is provided on the upstream side in the wire advancing direction of the cutting object passing area of the wire group 41.
Are extended in a direction orthogonal to the direction in which the wire group 41 is stretched, and a slurry supply hole (not shown) is formed at a lower portion thereof so as to extend along the longitudinal direction of the pipe 43. Inside the triangular area formed by the rollers 42a to 42c, a receiving tank 44 for receiving the slurry flowing down from the wire group 41 constituting the horizontal surface is provided. A slurry tank 45 is connected to the receiving tank 44, and a stirrer 45a is provided therein.

The slurry tank 45 has a pipe T31 for supplying the slurry prepared in the mixing tank 2, a supply pipe T4 for supplying the slurry in the slurry tank 45 to the slurry supply pipe 43, and a slurry T4. A pipe T41 for discharging is connected. A circulation valve V4 and a pump P4 are provided in the middle of the supply pipe T4, and a discharge valve V41 is provided in the middle of the pipe T41. Then, the supply valve V31, the circulation valve V4, and the discharge valve V41
Are configured to be opened and closed by the controller C2.

As shown in FIG. 1, each wire saw W1, W
The waste slurry storage tank 5 for storing waste slurry is provided in the slurry tanks 45 of 2, W3, and W4, and the pipes T41, T42,
They are connected via T43 and T44, and a stirrer 50 is disposed inside them. A decanter 6 as first separation and recovery means is connected to the downstream side of the waste slurry storage tank 5 via a pipe T5 provided with a valve V5 and a pump P5.

The decanter 6 is a means for removing fine-grain components finer than the abrasive grains and the base oil from the waste slurry discharged from the wire saw by centrifugal separation to collect reusable abrasive grains. The decanter 6 is configured as shown in FIG. 4, for example. That is, inside the decanter body 61 is disposed a screw conveyor 62 is Tsu along the length direction, the screw 62a is formed in a spiral shape on the outer peripheral surface thereof. An inner cylinder 63 is provided on the outer periphery of the screw conveyor 62. And
The screw conveyor 62 is rotated directly by the motor 64, and the inner cylinder 63 is rotated by the motor 64 at a different rotation speed from the screw conveyor 62 via the belt 64a.

The decanter main body 61 has an abrasive outlet 61a for discharging abrasive particles as solid components separated by centrifugation, and a base oil outlet 61b for discharging fine particles and base oil finer than the separated abrasive particles. Are formed. A slurry supply path 62b is formed inside the screw conveyor 62. The abrasive discharge port 61a of the decanter 6 is connected to the mixing tank 2 via a first pipe T6 serving as a transporting unit for transferring the separated abrasive particles to the mixing tank 2. Further, the base oil outlet 61
b is the second through a pipe T61 equipped with a pump P61.
Is connected to a filter 7 as separation and recovery means.

The filter 7 is made of, for example, a non-woven fabric or the like, and is sent from the decanter 6 via a pipe T61.
From a base oil containing finer components finer than abrasive grains,
The base oil is recovered by removing fine particles. In addition, the filter 7 is connected to the mixing tank 2 upstream of the mixing tank 2 via a second pipe T7 serving as a transport unit for transferring the recovered base oil to the mixing tank 2. 2
It is connected to the. In this embodiment, a decanter 6 serving as a first separating and collecting means and a filter 7 serving as a second separating and collecting means constitute a separating and collecting means.

Next, the operation of the slurry management system configured as described above will be described. In the slurry management system, first, the valve V21 on the hopper 21 side is opened, a predetermined amount of abrasive grains is supplied from the hopper 21 to the mixing tank 2 via the screw feeder 21a, and the valve V22 is opened. Oil tank 22 by pump P22
A predetermined amount of base oil is supplied to the mixing tank 2 from the above. Then, the abrasive grains and the base oil are mixed by the stirrer 20 in the mixing tank 2 to form a slurry. The prepared slurry is temporarily stored in the slurry storage tank 3 by opening the valve V2, and then supplied to the slurry tank 45 of each wire saw W1 to W4 by the pump P3 with the opening of the valve V3 and the supply valves V31 to V34. .

As the new abrasive particles supplied from the hopper 21, particles having an average particle diameter of 5 to 30 μm, such as silicon carbide, boron carbide, diamond, and boron nitride, are used. Abrasive grains having such a particle size are suitable for cutting a wafer with a wire saw. Further, the mixing weight ratio of the abrasive grains and the base oil in the slurry prepared and formed in the preparation tank 2 is set in the range of 1: 0.91 to 1: 0.6. For example, from hopper 21 to 100k
g of abrasive grains are supplied and oil tanks 22 to 89
kg of base oil is supplied and the mixing weight ratio is 1:
A slurry of 0.89 is produced. Further, the viscosity of the slurry is set within a range of 150 to 220 cP (centipoise) when the base oil is of a high viscosity type, and within a range of 40 to 60 cP when the base oil is of a low viscosity type. Is done.

In each of the wire saws W1 to W4, the cut object 46 is cut. This cutting will be described with reference to FIG. 3 using the first wire saw W1 as an example. First, the circulation valve V is controlled by the controller C2.
4 is opened, and the supply valve V31 and the discharge valve V41 are closed. Then, the slurry supplied to the slurry tank 45 is supplied to the wire group 41 via the slurry supply pipe 43 by the pump P4. In this state,
The object to be cut 46 is moved from above the wire group 41 to the wire group 41.
, And the object to be cut 46 is cut by the wire group 41 traveling with the abrasive particles attached, and a large number of wafers are simultaneously formed.

At the time of this cutting, the slurry supply pipe 4
The slurry supplied from the wire 3 to the wire group 41 flows down from the wire group 41 and then flows through the receiving tank 44 into the slurry tank 4.
5 and is again circulated and supplied to the slurry supply pipe 43 via the pipe T4. Here, the slurry used for the cutting treatment includes, for example, abrasive grains having an average particle diameter of 10 to 30 μm or the same, and 5 to 15 μm crushed by cutting.
crushed abrasive grains with an average particle size of
It contains cutting powder of the object to be cut having a particle size of about several μm and metal powder coming out of the wire.

As described above, when the cutting of the object to be cut 46 is repeatedly performed, the amount of cutting powder and metal powder in the slurry gradually increases, and the cutting function decreases. For this reason, at the predetermined number of times, for example, at the time of the second processing, the discharge valve V41 is opened for a predetermined time by the controller C2, and the used slurry in the slurry tank 45 is partially discharged through the pipe T41. At the same time, the supply valve V31 is opened for a predetermined time by the controller C2, and new slurry prepared in the preparation tank 2 shown in FIG. 1 is supplied to the slurry tank 45 via the slurry storage tank 3 and the pipe T31 in a predetermined amount. Then, the slurry is regenerated in parallel with the cutting of the workpiece 46. Before the cutting of the next object 46 is started, the supply valve V31 is controlled by the controller C2.
And the discharge valve V41 is closed.

On the other hand, the waste slurry discharged from each of the wire saws W1 to W4 is once stored in a waste slurry storage tank 5 shown in FIG. 1, and then sent to a decanter 6 with opening of a valve V5. In the decanter 6, the waste slurry is supplied into the decanter main body 61 via a supply path 62b shown in FIG. Then, the screw conveyor 62 and the inner cylinder 63 are rotated at different rotation speeds by the motor 64, whereby centrifugal force is applied to the slurry. As a result, the abrasive grains in the slurry settle down on the inner wall of the decanter main body 61, and the base oil containing fine powder components, such as cutting powder, crushed abrasive grains and metal powder, forms a layer inside the abrasive grains. And placed separately.

Further, the base oil containing the fine particle component is sent to the filter 7 through a pipe T61 by a pump P61 shown in FIG.
Fine particle components such as crushed abrasive grains and metal powder are separated and removed. The base oil separated by the filter 7 is supplied to a pipe T7.
And the abrasive particles separated by the decanter 6 through the
6 to the mixing tank 2.

In the decanter 6, the aforementioned 5-30
150-500 suitable for separation and recovery of abrasive particles with a particle size of μm
At a centrifugal acceleration of G, for example, 300 G, the abrasive particles are separated and collected through a residence time of 80 seconds.
The recovery rate of the abrasive grains separated and recovered from the waste slurry by the decanter 6 is set to be in the range of 85 to 95% by weight. Further, the recovery rate of fine particles such as cutting powder separated by the filter 7 is set within a range of 30 to 50% by weight, and the recovery rate of the base oil is set at 90% by weight.

In the mixing tank 2, the specific gravity and the viscosity of the slurry are detected by the hydrometer S1 and the viscometer S2, and the detected values are output to the controller C1.
Target values of the specific gravity and the viscosity of the slurry are previously input to the controller C1, and the opening degrees of the valves V21 and V22 are controlled based on a comparison output between the target values and the detected values. Supply amount and oil tank 22
The supply amount of the base oil from is adjusted.

That is, in the controller C1, the relationship between the detection values of the hydrometer S1 and the viscometer S2 and the content of the abrasive grains in the slurry is grasped in advance. A high ratio and a low specific gravity or viscosity are associated with a low abrasive content. here,
When the cutting of the object 46 is repeatedly performed, the amount of crushed abrasive grains increases, the amount of normal abrasive grains transferred from the decanter 6 to the mixing tank 2 gradually decreases, and the slurry in the mixing tank 2 The specific gravity or the viscosity of the rubber becomes lower. Therefore, in such a case, the opening degree of the valve V21 is increased, and the supply amount of the abrasive grains from the hopper 21 is increased.

Further, since fine oil components such as swarf, crushed abrasive grains, metal powder and the like separated by the filter 7 and removed to the outside of the system have base oil attached thereto, the amount of base oil conveyed to the mixing tank 2 is reduced. Gradually decreases, and the specific gravity or viscosity of the slurry in the preparation tank 2 increases. Therefore, in such a case, the opening degree of the valve V22 is increased, and the supply amount of the base oil from the oil tank 22 is increased. In this way, the mixture weight ratio between the abrasive grains and the dispersion in the prepared slurry is adjusted and maintained so as to be in the range of 1: 0.91 to 1: 0.6.

The effects that can be expected from the above embodiment will be described below. (A) In the slurry management system of this embodiment, abrasive grains and base oil are separated and recovered from the used waste slurry discharged from the wire saws W1, W2, W3, W4 and reused. For this reason, the amount of abrasive grains and base oil required for the cutting process of the object to be cut can be significantly reduced, and the cost can be reduced.

(B) In the slurry management system of this embodiment, the slurry can be continuously supplied to the wire saws W1, W2, W3, and W4, and the cutting by the wire saws W1, W2, W3, and W4 can be performed. Can be performed continuously. For this reason, the cutting efficiency of the object to be cut 46 can be improved. As a result, coupled with cost reduction by reusing abrasive grains and base oil,
The cutting of the object to be cut 46 can be performed at low cost.

(C) In the slurry management system of this embodiment, the specific gravity or the viscosity of the slurry is detected to grasp the content of the abrasive grains in the slurry, and the content of the abrasive grains is set to a set value. Slurry properties are managed by controlling the supply of abrasive grains and base oil. For this reason, it is possible to stably cut the object to be cut.

(D) In the slurry management system of this embodiment, since the base oil is reused, the amount of industrial waste is reduced, and the load of industrial waste treatment can be greatly reduced.

(E) In the slurry management system of this embodiment, the mixing weight ratio between the abrasive grains and the dispersion in the slurry to be prepared and mixed is in the range of 1: 0.91 to 1: 0.6. It is adjusted and maintained. When the mixing weight ratio of the slurry is set in this range, the best cutting conditions can be secured.

FIG. 5 is a graph showing the relationship between the mixing weight ratio of the abrasive grains and the dispersion in the slurry and the cutting load when the object to be cut is cut by the wire group of the wire saw. In addition, this graph was obtained when cutting was performed under the following conditions. That is, 100
Polycrystalline silicon in the form of a quadrangular prism of mm square was used.
Then, the object to be cut was cut by a wire having a diameter of 0.18 mm and running at a speed of 500 m / min. In this cutting, the larger the cutting load, the more efficiently the object to be cut can be cut. Therefore, based on the graph of FIG. 5, the mixing weight ratio between the abrasive grains and the dispersion liquid in the slurry is 1: 0.91 at which the cutting load increases.
From 1 to 0.6.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
Will be described with reference to FIG. By the way, in the slurry management system of the second embodiment, the first
The cyclone 8 is used as the separation and recovery means, and the decanter 6 is used as the second separation and recovery means. The abrasive grains are separated and collected from the waste slurry by the cyclone 8, and the fine particles and the base oil are separated from the remaining waste slurry by the decanter 6.

That is, in the cyclone 8, the abrasive grains contained in the waste slurry collide with the inner wall of the cyclone 8 under the action of the centrifugal force in the downward swirling flow, and are collected and discharged to the lower side. The base oil containing fine particles, which are finer than abrasive grains, crushed abrasive grains and metal powder, is discharged from the upper side on the upward swirling flow. Thereby, the abrasive grains are separated and collected from the waste slurry. Further, the base oil containing the separated fine particle component is sent to the decanter 6 via the pipe T61 by the pump P61, where it is separated into the fine particle component and the base oil.

The abrasive grains separated and recovered by the cyclone 8 are conveyed into the mixing tank 2 via the pipe T6. The base oil separated and recovered by the decanter 6 is combined with the abrasive grains in the pipe T6 on the way by the pipe T7,
It is transported into the mixing tank 2. Other methods, configurations and operations are the same as those of the first embodiment.

In the second embodiment, in the primary separation by the cyclone 8, the abrasive grains are separated and recovered at a centrifugal acceleration of 300 G, for a residence time of 80 seconds, for example. Also, 2 by decanter 6
In the subsequent separation, for example, the centrifugal acceleration of 2,000 to 3,000 G is performed to separate the fine particles from the base oil through a residence time of 50 seconds.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
Will be described with reference to FIG. By the way, in the slurry management system of the third embodiment, the first
A pair of first filters 9a and 9b are used as the separation and collection means, and a pair of second filters 9c and 9d are used as the second separation and collection means. Then, the first filter 9
a, 9b separates and collects abrasive grains from the waste slurry,
The fine particles and the base oil are separated from the remaining waste slurry by the second filters 9c and 9d.

That is, in the first filters 9a and 9b, by switching the three-way valve type switching valve V91, waste slurry is alternately supplied via the pipes T91 and T92 at predetermined time intervals, and the slurry is removed from the waste slurry. The grains are separated and collected. Then, the base oil containing the separated fine particles is sent to the second filters 9c and 9d via the pipe T61 by the pump P61. This second filter 9
In c and 9d, by switching the switching valve V92, the base oil is alternately supplied at predetermined time intervals through the pipes T93 and T94, and is separated into fine particles and base oil.

While the separation operation is interrupted by switching the switching valve V91, the first filters 9a and 9b are backwashed from the downstream side of the pipes T91 and T92 by opening and closing the valve V93 or V94. Oil is supplied and the inside filter surface is backwashed. Similarly, for the second filters 9c and 9d, while the separation operation is interrupted by switching the switching valve V92, the valve V
By opening or closing 95 or V96, backwashing oil is supplied from the downstream side of the pipes T93 and T94, and the inside filter surface is backwashed.

The abrasive particles separated and collected by the first filters 9a and 9b are conveyed into the mixing tank 2 via the pipe T6. Further, the base oil separated and collected by the second filters 9c and 9d joins the abrasive grains in the pipe T6 on the way through the pipe T7, and is conveyed into the mixing tank 2. Other configurations and operations are the same as those of the above-described first and second embodiments.

The present invention can be embodied with the following modifications. (1) Using a decanter as the first separation and collection means,
Using a cyclone as the second separation and recovery means.

(2) A cyclone is used as the first separation and recovery means, and a filter is used as the second separation and recovery means. (3) using a filter as the first separation and collection means,
Using a decanter as the second separation and recovery means.

(4) A filter is used as the first separating and collecting means, and a cyclone is used as the second separating and collecting means. (5) Using a decanter as the first separation and collection means,
Using a decanter as the second separation and recovery means.

(6) A specific gravity meter S1 and a viscometer S2 are provided in the slurry storage tank 3 to detect the content of abrasive grains in the slurry in the slurry storage tank 3. (7) A hydrometer S1 and a viscometer S2 are provided in a pipe T6 downstream of a junction with the pipe T7, and the pipe T6
To detect the content of abrasive grains in the slurry during the process.

(8) Mixing tank 2 and slurry storage tank 3
And forming the compounding means. (9) A configuration in which the abrasive grains and the base oil separated from the used waste slurry are transported to the slurry storage tank 3.

(10) A single wire saw or a plurality of different wire saws from the above-described embodiment are provided. (11) A configuration in which the content of abrasive grains in the slurry is detected by one of the specific gravity meter S1 and the viscometer S2.

(12) The abrasive content in the slurry is detected using an optical detection means such as a turbidity meter different from the specific gravity meter S1 and the viscometer S2. (13) The amount of the base oil attached to the fine particle component separated by the second separation and recovery means and removed to the outside of the system, and the amount of the crushed abrasive particles removed as the fine particle component are the first and second. Is determined by the separation and recovery performance of the separation and recovery means.
For this reason, these amounts should be checked in advance, and the content of the abrasive grains in the slurry should be grasped from the amounts of the abrasive grains and the base oil conveyed to the preparation tank 2.

(14) As a dispersion in the slurry, an aqueous dispersion is used instead of an oil dispersion. When an aqueous dispersion is used, the mixing weight ratio between the abrasive grains and the dispersion is preferably set in the range of 1: 0.76 to 1: 0.5. In this aqueous slurry, the content of abrasive grains is about 20% higher than that of the oil slurry of the above embodiment. In other words, in the case of the aqueous slurry, the abrasive grains are more difficult to mix in the mixing tank 2 than in the oil slurry.
Therefore, in order to stably supply the abrasive grains to the wire saw, it is necessary to increase the content of the abrasive grains. In the case where the aqueous slurry is used, by setting the mixing weight ratio in the above range, the most favorable cutting conditions can be secured, and the object to be cut can be efficiently cut. The viscosity of such an aqueous slurry is set, for example, in the range of 40 to 50 cP.

[0070]

The present invention is configured as described above, and has the following effects. Claims 1, 4, and 8
According to the described invention, the abrasive and the dispersion are reused
And the cost of the cutting process can be reduced.
In both cases, the amount of industrial waste can be reduced. Further
According to the present invention, the slurry is continuously applied to the wire saw.
Can be supplied to improve the work efficiency
it can. Moreover, according to the present invention, the reused slurry is
Can contribute to good cutting conditions.
Wear.

According to the second aspect of the present invention, the wire source
Of the specified mixture weight ratio suitable for cutting the workpiece
Oil-based slurry can be prepared,
Cutting can be performed efficiently.

According to the fifth aspect of the present invention, the wire source
Of the specified mixture weight ratio suitable for cutting the workpiece
Able to mix water-based slurry and cut workpiece
Can be performed efficiently. According to the invention of claim 7,
According to this, an abrasive having the best cutting conditions can be used.

According to the ninth aspect of the present invention, the most cutting
The slurry can be prepared by reusing abrasives with good conditions.
it can.

[0074] According to each aspect of the present invention 10, 11, 12, the first or second separation and recovery means or the first, the second both separation and recovery means, abrasive 及 from the slurry
And the dispersion are preferably separated and recovered by centrifugal force.

According to the thirteenth aspect, the primary component
Recovery of abrasive grains with the best cutting conditions in separation and recovery
It is done efficiently.

According to the fourteenth aspect of the present invention, in the secondary separation and recovery, the dispersion liquid is reliably separated by a high centrifugal force. According to the sixteenth aspect, at the time of preparing the slurry, the mixing weight ratio of the abrasive grains and the dispersion in the slurry or the viscosity of the slurry can be constantly maintained at the set value. According to the invention described in claim 17, the content of the abrasive grains in the slurry is detected, and the mixing weight ratio of the abrasive grains and the dispersion liquid or the viscosity of the slurry is always maintained at a set value based on the detection result. Can be. According to the invention described in claim 18, by measuring at least one of the specific gravity and the viscosity of the slurry, the content of the abrasive in the slurry is detected, and the mixing of the abrasive and the dispersion is performed based on the detection result. The weight ratio or viscosity of the slurry can always be maintained at the set value.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a wire saw.

FIG. 3 is a configuration diagram showing a wire saw and its related configuration.

FIG. 4 is a cross-sectional view showing a configuration of a decanter as a first separation and collection unit.

FIG. 5 is a graph showing a relationship between a mixing weight ratio of abrasive grains and a dispersion in a slurry and a cutting load.

FIG. 6 is a configuration diagram showing a second embodiment of the present invention.

FIG. 7 is a configuration diagram showing a third embodiment of the present invention.

FIG. 8 is a configuration diagram showing a conventional wire saw and its related configuration.

[Explanation of symbols]

Reference numeral 2 denotes a mixing tank constituting a mixing means; 21 a hopper as an abrasive supply unit; 22 an oil tank as a dispersion liquid supply unit;
1: Wire group, 42a, 42b, 42c: Roller, 43
... Slurry supply pipe, 45 ... Slurry tank, 46 ... Cutting object, 6 ... Decanter which constitutes the first separation and collection means in the first embodiment and constitutes the second separation and collection means in the second embodiment , 7... Filters constituting the second separation and recovery means in the first embodiment, 8.
In the embodiment of the present invention, the cyclone constituting the first separation and recovery means, V21...
22: a valve as a dispersion liquid supply amount adjusting unit; S1: a hydrometer which constitutes a specific gravity detecting unit as an abrasive content detecting unit;
2 ... Viscometer constituting a viscosity detecting section as an abrasive content detecting section, C1 ... Controller constituting a control means, W1,
W2, W3, W4 ... wire saw.

Continued on the front page (72) Inventor Noboru Katsumata 1 Shinmeicho, Yokosuka City, Kanagawa Prefecture Inside the Hihira Toyama Technical Center Co., Ltd. ) Inventor Toyohisa Wada 1 Shinmeicho, Yokosuka-shi, Kanagawa Pref., Japan Hibira Toyama Technical Center (72) Inventor Takaharu Nishida 2-2-8 Dojimahama, Kita-ku, Osaka-shi, Osaka Toyobo Co., Ltd. (72) Inventor Shoichi Uemura 2-1-1 Katata, Otsu City, Shiga Prefecture Toyo Boseki Co., Ltd. (72) Inventor Tetsuo Kodama 2-1-1 Katata, Otsu City, Shiga Prefecture Toyo Boseki Co., Ltd. (56) References JP-A-1-316170 (JP, A) JP-A-5-124026 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24B 57/02

Claims (18)

(57) [Claims] 1. A slurry obtained by dispersing abrasive grains in an oil-based dispersion liquid is supplied to a group of wires stretched in parallel with each other, and a workpiece is passed through the group of wires.
In a slurry management system for a wire saw configured to simultaneously obtain a large number of wafers , an abrasive and a dispersion are supplied to a mixing tank to mix the slurry.
A first separating and collecting means for separating and removing fine particles and dispersion liquid finer than abrasive grains from the slurry discharged from the wire saw to collect reusable abrasive grains; and A second separation and collection unit that separates and removes the fine particle component from the dispersion liquid containing the fine particle component that is separated and removed by the first separation and collection unit, and collects the dispersion liquid; and a collection by the first and second separation and collection units. Abrasive grain
And the dispersion liquid is merged on the way and transported to the blending tank.
Feeding means, wherein the mixing means uses the first and second separation and recovery means.
The abrasive particles and the dispersion recovered by
A slurry management system for a wire saw, wherein a slurry to be supplied to a yasaw is prepared . 2. A slurry prepared by the mixing means.
The mixing weight ratio between the abrasive grains and the dispersion in the mixture was 1: 0.
2. The method according to claim 1, wherein the value is set in a range of 91 to 1: 0.6.
Wire saw slurry management system. 3. The slurry has a viscosity of 150 to 220 cp.
3. A slurry tube for a wire saw according to claim 1 or 2.
Management system. 4. A slurry comprising abrasive grains dispersed in an aqueous dispersion liquid is supplied to a group of wires stretched in parallel with each other, and a large number of wafers are formed by passing a workpiece through the group of wires. In a slurry management system for a wire saw that is simultaneously obtained, a slurry is prepared by supplying abrasive grains and a dispersion to a preparation tank.
A first separating and collecting means for separating and removing fine particles and dispersion liquid finer than abrasive grains from the slurry discharged from the wire saw to collect reusable abrasive grains; and A second separation and collection unit that separates and removes the fine particle component from the dispersion liquid containing the fine particle component that is separated and removed by the first separation and collection unit, and collects the dispersion liquid; and a collection by the first and second separation and collection units. Abrasive grain
And the dispersion liquid is merged on the way and transported to the blending tank.
Feeding means, wherein the mixing means uses the first and second separation and recovery means.
The abrasive particles and the dispersion recovered by
A slurry management system for a wire saw, wherein a slurry to be supplied to a yasaw is prepared . 5. A slurry prepared by the mixing means.
The mixing weight ratio between the abrasive grains and the dispersion in the mixture was 1: 0.
5. The method according to claim 4, wherein the value is set in a range of 76 to 1: 0.5.
Wire saw slurry management system. 6. The slurry has a viscosity of 40-50 cp.
A slurry management system for a wire saw according to claim 4 or 5.
Stem. 7. The method according to claim 7, wherein the slurry supplied to the wire group is a new one.
The abrasive grains of the standard have an average particle size of 5 to 30 μm.
6. A wire saw slurry management system according to any one of 6.
M 8. with connecting a first pipe forming the conveying means for conveying the abrasive grains recovered by said first separation and recovery means to the blending tank to the blending tank, the second separation and recovery means 5. The wire saw slurry according to claim 1, wherein a second pipe serving as a transporting unit for transporting the dispersion liquid collected by the mixing tank to the mixing tank is merged with the first pipe upstream of the mixing tank. 6. Management system. 9. An abrasive which is reused when preparing a slurry.
5. The method according to claim 1, wherein the average particle size of the particles is 5 to 30 [mu] m.
A slurry management system for a wire saw as described. 10. The method according to claim 1, wherein the first separating and collecting means performs centrifugal separation.
Therefore, abrasive grains are removed from the slurry discharged from the wire saw.
The slurry of the wire saw according to claim 1 or 4, which is separated.
-Management system. 11. The wire saw slurry management system according to claim 1, wherein the second separation and recovery unit separates the dispersion liquid from the slurry discharged from the wire saw by centrifugal separation. 12. The first and second separation and recovery means,
The slurry management system for a wire saw according to claim 1 or 4, wherein the abrasive particles and the dispersion liquid are separated from the slurry discharged from the wire saw by centrifugation. 13. The centrifugation of the first separation and recovery means is performed by
The method is performed at a centrifugal acceleration of 50 to 500 G.
2. The slurry management system for a wire saw according to any one of 2.
M 14. The centrifugation of the second separation and collection means is performed by
The test is performed at a centrifugal acceleration of 000 to 3000 G.
13. The wire saw slurry management system according to any one of
Stem. 15. The number of first and second separation and recovery means is reduced.
One is a screw control provided inside the case.
To surround the conveyor and its screw conveyor.
And an inner cylinder rotatably provided in the case.
Item 15. A wire saw slurry according to any one of Items 10 to 14.
Management system. 16. A slurry prepared by the mixing means.
-Mixing ratio by weight of abrasive and dispersion in slurry or viscosity of slurry
Control the supply amount of abrasive and dispersion so that the degree becomes the set value.
7. A control device according to claim 1, further comprising:
Wire saw slurry management system. 17. The control device according to claim 16, wherein
Abrasive grain content detection unit that detects the percentage, and abrasive grain supply amount adjustment unit
The detection result of the dispersion liquid supply amount adjustment unit and the abrasive content detection unit
Abrasive supply adjustment unit and dispersion supply adjustment unit based on the result
17. A controller according to claim 16, further comprising:
Earsaw slurry management system. 18. The method according to claim 18, wherein the abrasive content detection unit detects the slurry content.
At least one of the specific gravity detector or the slurry viscosity detector
18. The wire saw slurry management according to claim 17, comprising:
system.