WO2020230423A1

WO2020230423A1 - Workpiece cutting method and wire saw

Info

Publication number: WO2020230423A1
Application number: PCT/JP2020/010008
Authority: WO
Inventors: 小林　健司
Original assignee: 信越半導体株式会社
Priority date: 2019-05-16
Filing date: 2020-03-09
Publication date: 2020-11-19
Also published as: KR20220008262A; JP7020454B2; CN113710397A; JP2020185649A; TW202042998A

Abstract

A workpiece cutting method according to the present invention is for simultaneously cutting a workpiece, by a wire saw, at a plurality of portions arranged axially by infeeding the workpiece held by a workpiece holding means with respect to wire rows which is formed by winding a fixed abrasive grain wire on a plurality of rollers with grooves, while supplying a coolant to the fixed abrasive grain wire and axially reciprocating the fixed abrasive grain wire, the cutting method being characterized in that the flow rate of the coolant is set to 180 L/min. or higher, and the traveling speed of the fixed abrasive grain wire in the axial direction is set to 6-30 m/min. after completion of cutting the workpiece and during pulling-out of the workpiece from the wire rows. Accordingly, it is possible to provide a workpiece cutting method that enables preventing the workpiece from being caught in the fixed abrasive grain wire to suffer a saw mark or preventing the fixed abrasive grain wire from being cut off, during the pulling-out of the cut workpiece from the fixed abrasive grain wire.

Description

Work cutting method and wire saw

The present invention relates to a work cutting method and a wire saw.

Conventionally, a wire saw is known as a means for cutting a wafer from a silicon ingot or a compound semiconductor ingot. In this wire saw, a wire row is formed by winding a large number of cutting wires around a plurality of rollers, the cutting wires are driven at high speed in the axial direction, and the wires are appropriately supplied with slurry. By cutting and feeding the work to the row, the work is cut at each position of the wire row at the same time (see Patent Document 1).

Here, FIG. 3 shows an outline of an example of a conventional general wire saw. As shown in FIG. 3, the wire saw 101 mainly includes a plurality of wires 102 (high-strength steel wire) for cutting the work W', grooved rollers 103 and 103' wound with the wires 102, and wires 102. Wire row 130 formed by being wound around the grooved rollers 103 and 103', tension adjusting mechanisms 104 and 104'that adjust the tension of the wire 102, and work feeding mechanism 105 that feeds the work W'to be cut downward. It is composed of a slurry supply mechanism 106 that supplies slurry at the time of cutting.

The wire 102 is unwound from one wire reel 107, passed through a traverser 108, a pulley 109, and a tension adjusting mechanism 104, wound around grooved rollers 103, 103'about 300 to 500 times, and then the other tension is adjusted. It is wound on a wire reel 107'through a mechanism 104', a pulley 109', and a traverser 108'.

Further, the grooved rollers 103 and 103'are rollers in which polyurethane resin is press-fitted around a steel cylinder and grooves are cut on the surface at a substantially constant pitch, and the wound wire 102 is a grooved roller drive motor. The 110 allows the vehicle to be driven in one direction or in a reciprocating direction at a predetermined cycle.

The wire reels 107 and 107'are rotationally driven by the wire reel drive motors 111 and 111', and the tension applied to the wire 102 is increased by controlling the speeds of the grooved roller drive motor 110 and the wire reel drive motors 111 and 111', respectively. Can be adjusted.

Further, as shown in FIG. 4, the work feeding mechanism 105 for feeding the work W'in FIG. 3 downward has a work holding means 114 composed of a work holding portion 112 and a work plate 113, and the work plate 113 has a work holding means 114. Is bonded to the work W'via a joining member (beam) 120 attached to the work W'.

When the work W'is cut, the work W'is relatively pushed down while being held by the work feed mechanism 105, and is fed out to a wire row 130 composed of wires 102 wound around the grooved roller 103.

Using such a wire saw 101, an appropriate tension is applied to the wire 102 by using the tension adjusting mechanisms 104 and 104', and the wire reel drive motors 111 and 111'move the wire 102 in the reciprocating direction while the slurry supply mechanism. Slurry is supplied from 106, and the work W'is cut and fed by the work feed mechanism 105 to cut the work W'.

On the other hand, there is also known a method of cutting a work by using a fixed abrasive wire in which diamond abrasive grains or the like are fixed to the surface of the wire without using a slurry containing abrasive grains, and the diameter is about 150 mm or less. It has been partially put to practical use for cutting small diameter wires.

In cutting with this fixed abrasive wire, a fixed abrasive wire is attached instead of the steel wire of the wire saw shown in FIG. 3, and the slurry is changed to a coolant such as cooling water that does not contain abrasive grains. The wire saw can be used as it is.

Japanese Unexamined Patent Publication No. 9-262826

Cutting with a fixed abrasive wire does not use free abrasive grains, so there is an advantage that there is little industrial waste from the environmental point of view. It also has the advantage of high processing speed, and is more convenient than processing with a wire saw using free abrasive grains. However, in the wire saw, as shown in FIG. 3, the work W'is pressed against one wire 102 wound around the grooved roller 103 to move and cut, so that the work W'is the work W'at the end of cutting. It is located below the wire 102 on which the'was pressed. Therefore, in order to take out the work W', by moving the work W'upward, the wire 102 is pulled out relatively downward through the gap of the work W'that has been cut into a wafer shape. There is a need.

In the case of a wire saw using free abrasive grains when pulling out the wire, as shown in FIG. 5A, there is a gap (clearance) between the wire 102 and the work W'by the width of the free abrasive grains G. Therefore, it was relatively easy to pull out the wire 102. However, as shown in FIG. 5B, in the case of a wire saw using fixed abrasive grains, there is no gap between the fixed abrasive grain wire 402 and the work W', so that the fixed abrasive grain wire 402 is difficult to come off. ..

Therefore, the fixed abrasive grain wire 402 is lifted by being caught by the work W', and if the fixed abrasive grain wire 402 is pulled out in this state, the work cut surface is damaged and a so-called saw mark is generated on the cut surface. Worp worsens and impairs quality. If the floating of the fixed abrasive grain wire 402 becomes larger, the wire may be broken. When a wire break occurs, it takes time and effort to rewind the fixed abrasive wire on the grooved roller, and an extra fixed abrasive wire for rewinding is required, resulting in a large loss.

The present invention has been made in view of the above-mentioned problems, and when the fixed abrasive wire is pulled out after cutting the work, the fixed abrasive wire is caught on the work and a saw mark is generated, or the fixed abrasive wire is broken. It is an object of the present invention to provide a method of cutting a work and a wire saw which are not used.

In order to achieve the above object, the present invention forms a wire row by winding a fixed abrasive wire having abrasive grains fixed on the surface around a plurality of grooved rollers, and applies a coolant to the fixed abrasive wire. By supplying and reciprocating the fixed abrasive wire in the axial direction, the work held by the work holding means via the joining member attached to the work is cut and fed to the wire row. In a method of cutting a work with a wire saw that simultaneously cuts the work at a plurality of locations arranged in the axial direction.
After the work has been cut and when the work is pulled out from the wire row, the flow rate of the coolant is 180 L / min. With the above, the traveling speed of the fixed abrasive grain wire in the axial direction is 6 m / min. As mentioned above, 30 m / min. Provided is a method for cutting a work, which is characterized by the following.

According to the work cutting method of the present invention, the lubricity between the work and the fixed abrasive wire can be improved, and the fixed abrasive wire can be prevented from being caught when the work is pulled out. Therefore, according to the work cutting method of the present invention, it is possible to prevent the occurrence of saw marks and the occurrence of disconnection of the fixed abrasive wire due to the fixed abrasive wire being caught on the work.

At this time, the flow rate of the coolant was changed to 250 L / min. The following is preferable.
By suppressing the supply of coolant in this way, it is possible to reduce the amount of coolant used while obtaining the above-mentioned effects.

Further, in order to achieve the above object, the present invention has a wire row formed by winding a fixed abrasive wire with abrasive grains fixed on the surface around a plurality of grooved rollers.
A coolant supply mechanism that supplies coolant to the fixed abrasive wire,
It is provided with a work feeding mechanism that cuts and feeds the work with respect to the wire row while holding the work by the work holding means via a joining member attached to the work.
A wire saw that simultaneously cuts the work at a plurality of locations aligned in the axial direction by cutting and feeding the work to the wire row by the work feed mechanism while reciprocating the fixed abrasive wire in the axial direction. There,
After the work has been cut and when the work is pulled out from the wire row, the flow rate of the coolant is 180 L / min. As described above, the traveling speed of the fixed abrasive grain wire in the axial direction is 6 m / min. As mentioned above, 30 m / min. Provided is a wire saw characterized in that it is controlled below.

With the wire saw of the present invention, the lubricity between the work and the fixed abrasive wire can be improved, and the fixed abrasive wire can be prevented from being caught when the work is pulled out. Therefore, the wire saw of the present invention can prevent the occurrence of saw marks and the occurrence of disconnection of the fixed abrasive wire due to the fixed abrasive wire being caught on the work.

Further, the flow rate of the coolant is 250 L / min. It is preferably as follows.
By suppressing the supply of the coolant in this way, it is possible to suppress the amount of the coolant used while obtaining the above-mentioned effects.

As described above, in the work cutting method and wire saw of the present invention, the saw mark and the fixed abrasive wire are broken due to the fixed abrasive wire being caught in the work when the fixed abrasive wire is pulled out after cutting the work. Can be prevented. As a result, it is not necessary to rewind the fixed abrasive wire due to contact with the work and to add the fixed abrasive wire for the rewinding, and the work can be cut one after another with one wire saw.

It is the schematic which shows an example of the wire saw which can be used for the cutting method of the work of this invention. (A) It is a figure which shows the positional relationship between a work and a fixed abrasive wire at the end of cutting of a work. (B) It is a figure which shows the state of the work and the fixed abrasive grain wire at the time when the wire is caught. (C) It is a figure which shows the positional relationship between a work and a fixed abrasive wire at the end of drawing of a work. It is a schematic diagram which shows an example of a general wire saw. It is the schematic which shows an example of the work holding means of a general wire saw. (A) It is explanatory drawing which shows the pulling out of a wire in the case of the wire saw which used the free abrasive grain (free abrasive grain method). (B) It is explanatory drawing which shows the extraction of the wire in the case of the wire saw which used the fixed abrasive grain wire (fixed abrasive grain method).

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

As described above, when cutting a work using fixed abrasive wire, when the work after cutting is pulled out from the wire row, the fixed abrasive wire is caught on the work, causing saw marks on the cut surface, or fixed abrasive. There was a problem that the grain wire was broken.

Therefore, the present inventor has made extensive studies to solve such problems. As a result, in the method of cutting a work with a wire saw using a fixed abrasive wire, the coolant flow rate and the traveling speed of the fixed abrasive wire in the axial direction are determined after the work has been cut and when the work is pulled out from the wire row. The present invention was completed by discovering that the fixed abrasive wire can be pulled out without being caught by the work.

That is, in the present invention, a fixed abrasive wire having abrasive grains fixed on the surface is wound around a plurality of grooved rollers to form a wire row, and coolant is supplied to the fixed abrasive grain wire to supply the fixed abrasive. While the grain wire is reciprocated in the axial direction, the work held by the work holding means via the joining member attached to the work is cut and fed to the wire row, whereby the work is axially reciprocated. In the method of cutting a work with a wire saw that cuts at multiple points in a row at the same time,
After the work has been cut and when the work is pulled out from the wire row, the flow rate of the coolant is 180 L / min. With the above, the traveling speed of the fixed abrasive grain wire in the axial direction is 6 m / min. As mentioned above, 30 m / min. It is a work cutting method characterized by the following.

Further, the present invention comprises a wire row formed by winding a fixed abrasive wire having abrasive grains fixed on the surface around a plurality of grooved rollers.
A coolant supply mechanism that supplies coolant to the fixed abrasive wire,
It is provided with a work feeding mechanism that cuts and feeds the work with respect to the wire row while holding the work by the work holding means via a joining member attached to the work.
A wire saw that simultaneously cuts the work at a plurality of locations aligned in the axial direction by cutting and feeding the work to the wire row by the work feed mechanism while reciprocating the fixed abrasive wire in the axial direction. There,
After the work has been cut and when the work is pulled out from the wire row, the flow rate of the coolant is 180 L / min. As described above, the traveling speed of the fixed abrasive grain wire in the axial direction is 6 m / min. As mentioned above, 30 m / min. It is a wire saw characterized in that it is controlled as follows.

Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

[Wire saw]
First, a wire saw that can be used in the work cutting method of the present invention will be described with reference to FIG. As shown in FIG. 1, the wire saw 1 of the present invention mainly includes a fixed abrasive grain wire 2 in which abrasive grains are fixed to a surface for cutting a work W, and a grooved roller around which the fixed abrasive grain wire 2 is wound. 3,3', wire row 30 formed by winding fixed abrasive wire 2 around a plurality of grooved rollers 3,3', work feed for feeding the work W to be cut downward with respect to the wire row 30. It is composed of a mechanism 5 and a coolant supply mechanism 6 that supplies coolant to the fixed abrasive wire 2.
Like the conventional work feed mechanism 105, the work feed mechanism 5 has a work holding means as shown in FIG. 4, and the work holding means is a joining member (beam) 20 (beam) 20 attached to the work W. The work W is held through FIG. 1).

The wire saw 1 can further include tension adjusting mechanisms 4, 4'that adjust the tension of the fixed abrasive grain wire 2.
In FIG. 1, the fixed abrasive grain wire 2 is unwound from one wire reel 7, passes through a traverser 8, a pulley 9, and a tension adjusting mechanism 4, and is wound around a grooved roller 3, 3'about 300 to 500 times. After that, it is wound on a wire reel 7'through the other tension adjusting mechanism 4', a pulley 9', and a traverser 8'.

Grooved rollers 3 and 3'are, for example, rollers in which polyurethane resin is press-fitted around a steel cylinder and grooves are cut on the surface at a substantially constant pitch, and the wound fixed abrasive wire 2 is grooved. The roller drive motor 10 can drive the motor in one direction or in a reciprocating direction at a predetermined cycle.

The wire reels 7 and 7'are rotationally driven by the wire reel drive motors 11 and 11', and by controlling the speeds of the grooved roller drive motor 10 and the wire reel drive motors 11 and 11', respectively, the fixed abrasive wire 2 is formed. The tension can be adjusted.

In such a wire saw 1, a plurality of work W are arranged in the axial direction by cutting and feeding the work W to the wire row 30 by the work feed mechanism 5 while reciprocating the fixed abrasive grain wire 2 in the axial direction. Cut at the same time at.
In the reciprocating travel of the fixed abrasive grain wire 2, the fixed abrasive grain wire 2 wound between the plurality of grooved rollers 3 and 3'is advanced in one direction by a predetermined length, and then the above-mentioned advance amount is advanced in the other direction. It is performed by a method such as feeding the wire in one direction by retreating the wire by a length smaller than that of the wire and using this as a one-feed cycle and repeating this cycle. The grooved roller 3'is such that the wound fixed abrasive grain wire 2 can be driven in the reciprocating direction by the grooved roller drive motor 10 at a predetermined cycle.

Further, in the wire saw 1 of the present invention, when the work W is pulled out from the wire row 30 after the cutting of the work W is completed, the flow rate of the coolant is 180 L / min. With the above, the traveling speed of the fixed abrasive grain wire 2 in the axial direction is 6 m / min. As mentioned above, 30 m / min. It is controlled as follows.

Here, (a) and (c) of FIG. 2 show the positional relationship between the work W at the end of cutting the work and the end of drawing out the work and the fixed abrasive grain wires 202 wound around the grooved rollers 203 and 203', respectively. It is a figure which showed. As shown in FIG. 2A, the work W is located below the wire row at the end of cutting. Therefore, in order to take out the work W, the work W is moved upward so as to pass through the gap between the wafers of the work W which has been cut into a wafer shape, and the fixed abrasive grain wire 202 is relatively downward. Need to pull out.

However, in the case of a conventional wire saw using such a fixed abrasive wire, there is no clearance between the fixed abrasive wire 202 and the work W (see FIG. 5B), so that the fixed abrasive wire The 202 is caught by the work W and floats up as shown in FIG. 2B, so that a saw mark is generated on the cut surface of the work W and a wire is broken.

On the other hand, in the wire saw 1 of the present invention, the coolant flow rate and the traveling speed of the fixed abrasive wire 2 in the axial direction are controlled by the controller 31 as described above, thereby between the work W and the fixed abrasive wire 2. It is possible to improve the lubricity and prevent the fixed abrasive grain wire 2 from being caught when the work W is pulled out. Therefore, the wire saw 1 of the present invention can prevent the occurrence of saw marks and the occurrence of disconnection of the fixed abrasive wire due to the fixed abrasive wire 2 being caught on the work W.

Further, the flow rate of the coolant is 250 L / min. It is preferably as follows.
By suppressing the supply of coolant in this way, it is possible to reduce the amount of coolant used while obtaining the above-mentioned effects.

[Work cutting method]
Subsequently, the method of cutting the work of the present invention will be described by taking the case of using the wire saw of the present invention as an example. First, as shown in FIG. 1, a wire row 30 is formed by winding a fixed abrasive wire 2 having abrasive grains fixed on its surface around a plurality of grooved rollers 3 and 3'. Subsequently, the fixed abrasive grain wire 2 is reciprocated in the axial direction of the fixed abrasive grain wire 2 by the grooved roller drive motor 10. At this time, an appropriate tension is applied to the fixed abrasive grain wire 2 by using the tension adjusting mechanisms 4 and 4', and the fixed abrasive grain wire 2 is moved in the reciprocating direction by the wire reel drive motors 11 and 11', and the fixed abrasive grain wire 2 is fixed. The tension applied to the grain wire 2 can be adjusted. Then, the coolant is supplied from the coolant supply mechanism 6 to the fixed abrasive grain wire 2, and while the fixed abrasive grain wire 2 travels in the reciprocating direction, the work holding means is passed through the joining member 20 attached to the columnar work W. By cutting and feeding the work W held in 1 to the wire row 30, the work W is simultaneously cut at a plurality of locations aligned in the axial direction.

The above is the same as the work cutting method described above, but in the work cutting method of the present invention, when the work W is pulled out from the wire row 30 after the work W has been cut, the coolant flow rate is 180 L / min. With the above, the traveling speed of the fixed abrasive grain wire 2 in the axial direction is 6 m / min. As mentioned above, 30 m / min. It differs from the normal work cutting method in the following points.

With the work cutting method of the present invention as described above, the lubricity between the work W and the fixed abrasive wire 2 can be improved, and the fixed abrasive wire 2 can be prevented from being caught when the work W is pulled out. Therefore, according to the work cutting method of the present invention, it is possible to prevent the occurrence of saw marks and the occurrence of disconnection of the fixed abrasive wire due to the fixed abrasive wire 2 being caught on the work W.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention, but the present invention is not limited thereto.
(Examples and comparative examples)

Using the wire saw 1 of the present invention as shown in FIG. 1, the columnar work W was cut according to the method of cutting the work of the present invention, and the work W was pulled out from the wire row 30. The work was cut and the work was pulled out using the work cutting method of the comparative example. Table 1 shows the common conditions of the examples and the comparative examples.

Next, Table 2 shows the conditions when the workpieces of Examples and Comparative Examples have been cut and the workpieces are pulled out from the wire row. The results are shown in Table 3.

As a result, as shown in Table 3, the flow rate of the coolant was changed to 180 L / min when the work was pulled out from the wire row after the work was cut. With the above, the traveling speed of the fixed abrasive grain wire in the axial direction is 6 m / min. As mentioned above, 30 m / min. In Examples 1 to 6 described below, no disconnection or saw mark occurred during pulling out. On the other hand, in Comparative Examples 1 to 8 in which at least one of the coolant flow rate and the traveling speed in the axial direction of the fixed abrasive wire was out of the range of the present invention, disconnection and saw mark were confirmed at the time of drawing.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

Claims

A wire row is formed by winding a fixed abrasive wire having abrasive grains fixed on the surface around a plurality of grooved rollers, coolant is supplied to the fixed abrasive grain wire, and the fixed abrasive grain wire is axially rotated. While reciprocating, the work held by the work holding means via the joining member attached to the work is cut and fed to the wire row, so that the work can be simultaneously arranged at a plurality of locations arranged in the axial direction. In the method of cutting a work with a wire saw to be cut,
After the work has been cut and when the work is pulled out from the wire row, the flow rate of the coolant is 180 L / min. With the above, the traveling speed of the fixed abrasive grain wire in the axial direction is 6 m / min. As mentioned above, 30 m / min. A method for cutting a workpiece, which comprises the following.
The flow rate of the coolant was 250 L / min. The method for cutting a work according to claim 1, wherein the work is cut as follows.
A wire row formed by winding a fixed abrasive wire with abrasive grains fixed on the surface around a plurality of grooved rollers, and
A coolant supply mechanism that supplies coolant to the fixed abrasive wire,
It is provided with a work feeding mechanism that cuts and feeds the work with respect to the wire row while holding the work by the work holding means via a joining member attached to the work.
A wire saw that simultaneously cuts the work at a plurality of locations aligned in the axial direction by cutting and feeding the work to the wire row by the work feed mechanism while reciprocating the fixed abrasive wire in the axial direction. There,
After the work has been cut and when the work is pulled out from the wire row, the flow rate of the coolant is 180 L / min. As described above, the traveling speed of the fixed abrasive grain wire in the axial direction is 6 m / min. As mentioned above, 30 m / min. A wire saw characterized in that it is controlled as follows.
The flow rate of the coolant is 250 L / min. The wire saw according to claim 3, wherein the wire saw is as follows.