WO2019077790A1

WO2019077790A1 - Multi-wire saw device

Info

Publication number: WO2019077790A1
Application number: PCT/JP2018/019342
Authority: WO
Inventors: 洋貴井上; 貴行近藤
Original assignee: 株式会社Tkx
Priority date: 2017-10-17
Filing date: 2018-05-18
Publication date: 2019-04-25
Also published as: JP6412284B1; JP2019075531A

Abstract

[Problem] To provide a multi-wire saw device that is capable of reducing kerf loss while suppressing breakage of a slicing wire material. [Solution] A multi-wire saw device 10 includes a wire saw 30 that is repeatedly laid between groove-provided rollers 12A, 12B so as to form a wire-saw row 30L. The wire saw 30 bridges the two rollers 30A, 30B in a state of being twisted so as to bring a first main surface 30A into contact with the groove-provided roller 12A and a second main surface 30B into contact with the groove-provided roller 12B, and an end surface 32A to which abrasive grains 34A-34C have been fixed is pressed against a silicon ingot 20.

Description

Multi-wire saw device

The present invention relates to a multi-wire saw device for slicing an ingot, and more particularly to a multi-wire saw device in which a wire for slicing is placed between feed rollers.

An ingot such as single crystal or polycrystalline silicon is processed into a wafer using a multi-wire saw device. This multi-wire saw device comprises a plurality of feed rollers and a wire rod for slicing which is repeatedly mounted between the rollers. Then, the multi-wire saw device processes the ingot into a wafer by pressing the ingot while moving the slicing wire in a predetermined direction by the rotation of the feed roller.

By the way, when an ingot is processed into a wafer using a multi-wire saw device, kerf loss (cutting waste) is generated, but in order to improve productivity, the amount of kerfloss generated is reduced by thinning the wire rod for slice processing. There is a need.

For this reason, it is conceivable to thin the wire for slicing, but the cross-sectional area decreases as the wire is thinned, and the tensile strength is lowered, and the wire for slicing is easily broken. There's a problem.

Patent Document 1 discloses a multi-wire saw device in which tensile strength is ensured by making the cross-sectional shape of a wire for slicing a substantially rectangular shape, and the amount of kerf loss generated is reduced by slicing an ingot with this wire end face. It is done.

Patent No. 3943584 gazette

However, in the multi-wire saw device described in Patent Document 1 above, since the wire for processing is run while being twisted by 90 ° by the guide installed in the vicinity of the ingot, the frictional force between the wire and the guide is large. There is a problem that it becomes easy to break.

An object of the present invention is to provide a multi-wire saw device capable of reducing kerf loss while suppressing breakage of a wire for slicing.

In the multi-wire saw device according to the present invention, a processing wire rod row formed by repeatedly straddling a slicing wire rod having a width larger than the thickness between the first feed roller and the second feed roller is predetermined along with the rotation of both feed rollers. A multi-wire saw device for slicing a silicon ingot by pressing it against a silicon ingot while traveling in a direction, wherein the wire rod for slicing has a first main surface in contact with the first feed roller and a side opposite to the first main surface The widthwise end portion is twisted so as to be pressed against the silicon ingot by being bridged between the feed rollers so that the second main surface of the above is in contact with the second feed roller.

Further, at least one of the first feed roller and the second feed roller may be provided with a groove portion formed of a first inclined surface and a second inclined surface having different lengths.

In the multi-wire saw device of the present invention, the multi-wire saw device may further include a guide member for guiding the end in the width direction of the wire for slice processing to be pressed against the silicon ingot.

Furthermore, the guide member may be inclined with respect to the traveling direction of the wire for slicing.

According to the multi-wire saw device of the present invention, the first main surface is in contact with the first feed roller, and the second main surface opposite to the first main surface is sliced between the feed rollers so that the second main surface is in contact with the second feed roller. The wire rod is bridged. Thereby, the silicon ingot can be sliced while pressing the end in the width direction of the wire for slicing to the silicon ingot. For this reason, the generation amount of kerf loss which occurs at the time of slice processing can be reduced. In addition, since the width of the wire for slicing is larger than the thickness, the cross-sectional area can be made larger than in the case where the width is only equal to the thickness, and breakage of the wire for slicing can be suppressed at the time of slicing. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the multi wire saw apparatus which concerns on one Embodiment of this invention. FIG. 2 is a perspective view more specifically showing the configuration around the processing area included in FIG. 1. It is a figure which shows the multi wire saw apparatus of the modification 1. FIG. It is a figure which shows the multi wire saw apparatus of the modification 2. FIG. It is a figure which shows the multi wire saw apparatus of the modification 3. FIG. It is a figure which shows the grooved roller of the modification 4, (a) is a general view of a grooved roller, (b) is a figure which shows tilting of the saw wire by the grooved roller of this application, (c) is grooved other than this application. It is a figure which shows the example of a tilting of the saw wire by a roller. It is a figure which shows the multi-wire saw apparatus of the modification 5, (a) is a figure which made it a control member so that it might become contrast centering | focusing on the process area P, (b) inclines a guide member at the same angle. FIG.

Hereinafter, a multi-wire saw device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the traveling direction "X" shown in the figure indicates the horizontal direction. FIG. 1 is a schematic configuration view showing an entire configuration of a multi-wire saw device.

As shown in FIG. 1, the multi-wire saw device 10 includes two grooved rollers (first feed rollers) 12A whose rotation axes are parallel and a grooved roller (second feed rollers) 12B. A large number of guide grooves (not shown) are provided at equal pitches on the outer peripheral surface of each of the

grooved rollers

12A and 12B. The multi-wire saw device 10 further includes a supply reel 14A and a take-up reel 14B having a function of winding and storing a saw wire (wire for slicing).

Further, the multi-wire saw device 10 includes a saw wire row (processing wire row) 30L configured by the saw wire 30 unwound from the supply reel 14A being repeatedly and sequentially laid over the guide grooves of the

grooved rollers

12A and 12B.

The grooved roller 12A, the supply reel 14A, and the take-up reel 14B are each rotationally driven by the power of a corresponding motor (all not shown) or the like, and the saw wire 30 travels with the rotation. At this time, the grooved roller 12A, the supply reel 14A, and the take-up reel 14B rotate the saw wire 30 so that the traveling speed of the saw wire 30 is, for example, about 1000 m / min. On the other hand, the grooved roller 12B is driven to rotate by the frictional force generated between it and the traveling saw wire 30. The multi-wire saw device 10 is configured to reversely rotate the grooved roller 12A or the like to switch the traveling direction of the saw wire 30 to the traveling direction X or the opposite direction every time the traveling distance of the saw wire 30 reaches a preset distance. Be done.

The width of the guide grooves of the

grooved rollers

12A and 12B is determined in consideration of the same as the width of the core wire 32 of the saw wire 30 described later, or the particle diameter of the abrasive grains fixed to the end face 32A. Also, the depth of the guide groove is set such that the guided saw wire 30 does not meander, and is determined to be, for example, 0.1 to 1.0 t with respect to the thickness of the core wire 32.

The multi-wire saw device 10 further includes a pair of

liquid supply nozzles

18A and 18B having a supply port (not shown) of a coolant which is a coolant. Each of the

liquid supply nozzles

18A and 18B is disposed to face the upper side of the saw wire row 30L stretched between the grooved roller 12A and the grooved roller 12B with the silicon ingot 20 interposed therebetween.

Further, the silicon ingot 20 is bonded and fixed to a movable base 22 provided on a bisector of the distance between the two

rollers

12A and 12B via a discarding plate 22A. The movable base 22 has a function of moving up and down relatively parallel to the saw wire row 30L. Then, as the movable base 22 descends, the silicon ingot 20 is pressed against the saw wire row 30L to be cut and processed into a wafer. In the following description, a region where the silicon ingot 20 is pressed against the saw wire row 30L is referred to as a processing region P.

Next, the configuration around the processing area P will be described with reference to FIG. FIG. 2 is a perspective view showing the configuration around the processing area P. As shown in FIG. As shown in FIG. 2, the saw wire 30 is composed of a core wire 32 configured to have a width w larger than a thickness t, and

abrasive grains

34A, 34B, 34C fixed to one end face 32A of the core wire 32. Ru. In the present embodiment, as an example, the thickness t is 50 μm and the width w is 70 μm.

The cross section of the core wire 32, that is, the cross section of the plane orthogonal to the longitudinal direction, is formed in a so-called rounded rectangular shape in which both

end surfaces

32A and 32B are rounded in a substantially semicircular shape. As described above, since the shape of the end face 32A to which the abrasive grains 34A to 34C are fixed is rounded, the slice processing can be stably performed even if the contact angle between the saw wire 30 and the silicon ingot 20 slightly changes during the slice processing. it can.

Moreover, although the core wire 32 is comprised with high carbon steel wires, such as a piano wire, you may comprise it with resin materials, such as a carbon fiber raw material and a phenol resin.

Instead of the saw wire 30, for example, a saw wire 40 shown in FIG. 2 may be used. The saw wire 40 is constituted by a core wire 42 in which the thickness t1 on the side of the end face 42A to which the abrasive grains 44A to 44C are fixed and the thickness t2 on the side of the end face 42B are different. The thickness t2 on the end face 42B side is made equal to or slightly larger than the thickness t3 including the abrasive grains 44A to 44C on the end face 42A. The abrasive grains 44A to 44C hardly contact the comb teeth 54A to 54C of the

guide members

52 and 56, and the comb teeth 54A to 54C can be protected.

The abrasive grains 34A to 34C are fixed to the end face 32A of the core wire 32 by resin coating (not shown) such as elastic urethane resin or metal plating (not shown) using nickel etc. Abrasive grains may be fixed also to end face 32B, or abrasive grains may be fixed to the entire circumference of core wire 32.

Subsequently, a method of bridging the saw wire 30 to the

grooved rollers

12A and 12B will be described. As shown in FIG. 2, the saw wire 30 is wound around the grooved roller 12A such that the first major surface 30A is in contact with the grooved roller 12A. The end face 32 A is oriented between the

guide members

52 and 56 so as to face the silicon ingot 20, and the width w of the saw wire 30 is twisted so as to be perpendicular to the silicon ingot 20. Further, the second major surface 30B is twisted so as to be in contact with the grooved roller 12B. The saw wire 30 is twisted so that the first major surface 30A contacts the grooved roller 12A again. Thus, the saw wire row 30L is configured by repeatedly bridging between the both

rollers

12A and 12B so as to twist 360 ° while winding the saw wire 30 around the circumference of the both

rollers

12A and 12B.

The grooved roller 12B may be in contact with the first major surface 30A. That is, although the saw wire 30 is twisted when passing through the guide member 52, after passing through the guide member 56, the saw wire 30 is twisted back so as to be in the original state. While the saw wire 30 travels from the grooved roller 12B to 12A, it does not twist. Further, the second major surface 30B may be in contact with both grooved

rollers

12A and 12B. The twisting direction of the saw wire 30 is reversed to that described above.

Further, when the saw wire 30 is bridged between both

rollers

12A and 12B, when the wire 30 passes through the processing area P, it is twisted 180 ° in the first direction, and when the wire 30 passes below the processing area P It is also possible to twist 180 ° in the direction opposite to the first direction. Thus, by twisting the saw wire 30 in different directions every half turn, the magnitude of the twist angle of the saw wire 30 per round can be maintained at approximately 0 °.

Further, as shown in FIG. 2, instead of the saw wire 30 in which the abrasive grains 34A to 34C are fixed to only one end face 32A, a saw wire 130 in which the abrasive grains are fixed to both end faces may be used. The saw wire 130 is composed of a core wire 132 having the same configuration as the core wire 32 of the saw wire 30, and abrasive grains 134A to 134C and 134D to 134F fixed to both end faces 132A and 132B of the core wire 132, respectively. In this case, first, in the processing area P, slicing is performed in a state in which the saw wire 130 is bridged over both the

rollers

12A and 12B so that the abrasive grains 134A to 134C fixed to one end face 132A face the silicon ingot 20. I do. Then, when the abrasive grains 134A to 134C fixed to one end face 132A fall off due to friction during slicing and decrease, the abrasive grains 134D to 134F fixed to the other end face 132B are processed into the silicon ingot 20. The saw wire 30 is reinstalled between the two

rollers

12A and 12B so as to face each other in the region P. Thus, the number of times of use of the saw wire 130 can be increased.

After twisting the saw wire 130 from the grooved roller 12A by 180 ° and passing it over the grooved roller 12B, if it is passed from the grooved roller 12B to the grooved roller 12A without twisting, the end faces facing the silicon ingot 20 are designated 132A to 132B. Invert. As a result, after slicing with the abrasive grains 134A to 134C on the end face 132A side, subsequently, slicing is performed with abrasive grains 134D to 134F on the end face 132B side. Therefore, it is possible to slice alternately with the abrasive grains 134A to 134C and the abrasive grains 134D to 134F, and it is possible to process twice as usual.

In addition, the multi-wire saw device 10 may be provided with

guide members

52 and 56 between the

grooved rollers

12A and 12B and the processing area P, respectively. Since the

guide members

52 and 56 have the same configuration, in the following description, only the guide member 52 will be described.

The guide member 52 is composed of a substantially rectangular base 53 disposed so as to cross the row 30L directly below the saw wire row 30L, and a large number of

comb teeth

54A, 54B, 54C standing on the upper surface of the base 53. Ru. The comb teeth 54A to 54C are arranged at equal pitches, and the interval h is formed larger than the thickness t of the saw wire 30 (core 32) and smaller than the width w. As a result, the saw wire 30 can hold the end face 32A with the abrasive grains 34A to 34C fixed between the comb teeth 54A to 54C more reliably while facing the silicon ingot 20.

Further, as described above, since the saw wire 30 is spanned between the two

rollers

12A and 12B in a state of being twisted 180 °, the end face 32A is the same as that of the ingot 20 even at a position slightly away from the silicon ingot 20. It is held in a twisted state to turn to the side. For this reason, the saw wire 30 rubs against the comb teeth 54A to 54C when passing through the

guide members

52 and 56, as compared with the case where the saw wire 30 is not twisted and spanned over both the

rollers

12A and 12B. There is also a merit that the generated frictional force can be reduced.

According to the multi-wire saw device 10 of the present invention, the first main surface 30A is in contact with the first feed roller 12A, and the second main surface 30B opposite to the first main surface 30A is in contact with the second feed roller 12B. The saw wire 30 is bridged between the

rollers

12A and 12B. Therefore, the end face 32A of the saw wire 30 can be pressed against the silicon ingot 20. As a result, the silicon ingot 20 can be sliced using the end face 32A to which the abrasive grains 34A to 34C of the saw wire 30 are fixed. Further, by slicing the silicon ingot 20 using the end face 32A of the saw wire 30, it is possible to reduce the amount of kerf loss generated at the time of slicing. Furthermore, since the width w of the saw wire 30 is larger than the thickness t, the cross-sectional area can be larger than in the case where the width is only equal to the thickness, and breakage of the saw wire 30 can be suppressed during slicing.

Subsequently, a modification of the present embodiment will be described with reference to FIGS. 3 to 5. In the following description, the parts having the same configuration as the multi-wire saw device 10 of the present embodiment will be assigned the same reference numerals and descriptions thereof will be omitted as appropriate, and only different parts will be described.

<Modification 1>
FIG. 3 is a perspective view showing the configuration of the multi-wire saw device 100. As shown in FIG. As shown in FIG. 3, the multi-wire saw device 100 differs from the multi-wire saw device 10 in that the multi-wire saw device 100 includes a grooved roller 12C having the same configuration as the grooved roller 12B in addition to the

grooved rollers

12A and 12B. In this configuration, a saw wire 102 is used instead of the saw wire 30. The saw wire 102 differs from the saw wire 30 in that

abrasive grains

104A, 104B, 104C, and 104D are fixed to both end surfaces of the core wire 32, respectively. Then, the saw wire 102 is repeatedly stretched at equal pitches along the outer periphery of the grooved rollers 12A to 12C to form a saw wire row 102L. At this time, in the same manner as in the above embodiment, the saw wire 102 contacts both the grooved roller 12A with the first main surface 30A in contact and the grooved roller 12B with the second main surface 30B in contact with both rollers 12A, It is bridged to 12B. On the other hand, the saw wire 102 is stretched without being twisted when it is bridged from the grooved roller 12B to the grooved roller 12A via the grooved roller 12C. Also in this case, the same effect as that of the multi-wire saw device 10 in the above embodiment can be obtained.

<Modification 2>
FIG. 4 is a diagram showing the configuration of the multi-wire saw device 140. As shown in FIG. As shown in FIG. 4, the multi-wire saw device 140 differs from the multi-wire saw device 10 in that the multi-wire saw device 140 includes a guide member 120 instead of the

guide members

52 and 56. The guide member 120 includes a base 122 adhesively fixed to the bottom surface 20P of the silicon ingot 20, and a large number of

comb teeth

124A, 124B, 124C erected on the base 122. The saw wire 30 is disposed between the comb teeth 124A to 124C so as to be able to travel. The guide member 120 is made of a material that can be sliced by the saw wire 30, and is sliced by the saw wire 30 together with the silicon ingot 20.

Here, the saw wire 30 is twisted 180 ° between both the

rollers

12A and 12B. For this reason, in the processing area P provided so as to include the position at which the distance between the both

rollers

12A and 12B is equally divided, the saw wire 30 is twisted by about 90 °, and the end face 32A of the saw wire 30 is a silicon ingot. It will face in a state close to a bottom 20P of 20 and a near pair. Therefore, using the guide member 120 fixed to the bottom surface 20P is more effective than using the

guide members

52 and 56 disposed between the both

rollers

12A and 12B and the silicon ingot 20 for the saw wire 30 and the guide member 120. The frictional force generated between each of the comb teeth 124A to 124C can be reduced.

<Modification 3>
FIG. 5 is a diagram showing the configuration of the multi-wire saw device 170. As shown in FIG. As shown in FIG. 5, the multi-wire saw device 170 differs from the multi-wire saw device 10 in that the multi-wire saw device 170 includes

guide members

150 and 160 instead of the

guide members

52 and 56.

The

guide members

150 and 160 are adhesively fixed to both side surfaces of the silicon ingot 20, and have the same configuration. In the following description, only the guide member 150 will be described. The guide member 150 includes a base 152 fixed to the side surface 20S of the silicon ingot 20, and a large number of comb teeth 154A to 154C provided at the lower end of the base 152. The saw wire 30 is disposed between the comb teeth 154A to 154C so as to be able to travel. The guide member 150 is made of a material that can be sliced by the saw wire 30, and is sliced by the saw wire 30 together with the silicon ingot 20. Also in this case, the friction force between the saw wire 30 and the

guide members

150 and 160 can be reduced like the guide member 120 of the second modification. Alternatively, only one of the

guide members

150 and 160 may be fixed to the silicon ingot 20 and used.

<Modification 4>
A plurality of groove portions 60 having two

inclined surfaces

62 and 64 shown in FIG. 6A may be provided in the grooved roller 12B. As shown in FIG. 6 (b), the two

inclined surfaces

62, 64 have different lengths. The first inclined surface 62 has a larger inclination than the second inclined surface 64 with respect to the alignment direction of the saw wires 30. The first inclined surface 62 is inclined at or near the alignment direction of the saw wires 30. Therefore, the second inclined surface 64 is longer than the first inclined surface 62.

Since the saw wire 30 is passed over the two

grooved rollers

12A, 12B so as to be tensioned, the saw wire 30 can be either the first inclined surface 62 or the second inclined surface 64 when the saw wire 30 passes through the groove 60. Try to fall down. At this time, the inclination of the second inclined surface 64 is small with respect to the direction in which the saw wires 30 are arranged, and the first inclined surface 62 is almost perpendicular, so the saw wire 30 tends to fall toward the second plane 64. Since all the saw wires 30 fall in the same direction, all the saw wires 30 are wound around the roller 12B and advanced in a twisted state in the same direction.

As shown in FIG. 6C, in the case of the groove 66 having the same length of the first inclined surface 67 and the second inclined surface 68, the angle of any of the

inclined surfaces

67, 68 is the same. Therefore, the direction in which the saw wire 30 falls can not be determined. If the adjacent saw wires 30 are twisted in different directions, the saw wires 30 may contact each other and break, so the distance between the saw wires 30 needs to be increased. This configuration can avoid disconnection of the saw wire 30 due to the above-described cause, and can shorten the distance between the saw wires 30. If the distance between the saw wires 30 is short, the silicon ingot can be sliced thinly.

In the above description, while the saw wire 30 is transferred from the grooved roller 12B to the grooved roller 12A, the saw wire 30 is twisted by 180 °. However, since the angle of the second inclined surface 64 is not 0 ° with respect to the alignment direction of the saw wires 30, the saw wire is transferred while the saw wire 30 is transferred from the second feed roller 12B to the first feed roller 12A. 30 will twist more than 180 degrees.

Further, the groove 60 may be provided on the grooved roller 12A. By passing the guide member 52 at an angle to the alignment direction of the saw wires 30 by the grooved roller 12A, the saw wire 30 is aligned with the

comb teeth

54A, 54B, 54C of the guide member 52 when passing through the guide member 52. The

main surfaces

30A, 30B are easy to stand. Furthermore, the groove 60 may be provided only in the grooved roller 12A.

<Modification 5>
As shown in FIG. 7A, the guide member 52 may be inclined in a direction other than the direction perpendicular to the traveling direction of the saw wire 30. By inclining with respect to the advancing direction, the width of the saw wire row 30L is narrowed from the dotted line to the solid line. The space between the saw wires 30 after passing through the guide member 52 is narrowed, and the silicon ingot 20 can be sliced thinly. The inclination angles of the

guide members

52 and 56 may be symmetrical with respect to the processing area P (FIG. 7A) or may be inclined at the same angle (FIG. 7B). Further, while the

guide members

52 and 56 are inclined, the distance between the

comb teeth

54A, 54B and 54C may be changed to adjust the distance between the saw wires 30.

The present invention can also be carried out in variously modified, modified or modified forms based on the knowledge of those skilled in the art without departing from the spirit of the invention. Moreover, you may implement in the form which substituted any invention specific matter to the other technique in the range to which the same effect | action or effect arises.

10, 100, 140, 170: Multi-wire saw device 12A: Grooved roller (first feed roller)
12B: Grooved roller (second feed roller)
12C: Grooved roller 20: Silicon ingot 30, 102: Saw wire (wire for processing)
30A: 1st main surface 30B: 2nd

main surface

30L, 102L: Saw wire row (wire rod row for processing)
32: core 32A: end face (width direction end)
32B: End faces 34A to 34C, 134A to 134F:

Abrasive grains

52, 56, 120, 150, 160: Guide members Grooves: 60
Inclined surface: 62, 64

Claims

A processing wire rod row formed by repeatedly straddling a wire rod for slicing having a larger width than the thickness between the first feed roller and the second feed roller is run in a predetermined direction as the feed rollers rotate and the silicon ingot is made A multi-wire saw device for slicing a silicon ingot by pressing it, wherein
The wire rod for slicing is stretched between the feed rollers so that the first main surface contacts the first feed roller and the second main surface opposite to the first main surface contacts the second feed roller. Characterized in that the end in the width direction is twisted so as to be pressed against the silicon ingot by being passed;
Multi-wire saw device.
2. The multi-wire saw device according to claim 1, wherein at least one of the first feed roller and the second feed roller is provided with a groove having a first inclined surface and a second inclined surface having different lengths.
The multi-wire saw device according to claim 1 or 2, further comprising: a guide member for guiding the widthwise end of the wire rod for slicing so as to be pressed against the silicon ingot.
The multi-wire saw device according to claim 3, wherein the guide member is inclined with respect to the traveling direction of the wire for slicing.