JP2013027958A - Wire saw device and method for cutting workpiece, and method for manufacturing wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut a workpiece promptly by higher tension as compared to a conventional device without causing wire breakage.SOLUTION: A wire saw device 1 includes a cutting wire 4 wound between grooved rollers 2 and 3 one end of which is wound around a supply bobbin 5 via a first dancer roller 10 and the other end of which is wound around a collection bobbin 6 via a second dancer roller 13. The wire saw device 1 cuts a workpiece 7 at a plurality of rows of the wire 4 between the grooved rollers 2 and 3. The wire saw device is provided with: a first buffer bobbin 14 as a first buffer means disposed between the grooved rollers 2 and 3 the first dancer roller 10, a second buffer bobbin 18 as a second buffer means disposed between the grooved rollers 2 and 3 and the second dancer rollers 13; a third dancer roller 17 disposed between the grooved rollers 2 and 3 and the first buffer bobbin 14, and a fourth dancer roller 21 disposed between the grooved rollers 2 and 3 and the second buffer bobbin 18.

Description

  The present invention relates to a wire saw device that cuts a workpiece with a wire array of cutting wires by running a cutting wire passed through the outer periphery of a plurality of grooved rollers arranged at predetermined intervals, and a workpiece cutting using the same. The present invention relates to a method of manufacturing a wafer by cutting a workpiece into a plurality of wafers with a wire row of the wire saw apparatus to manufacture a wafer material.

  In this type of conventional wire saw apparatus, a workpiece is cut into a number of wafers by a wire array while controlling the tension of a wire stretched around a grooved roller to produce a wafer material. This is disclosed in Patent Document 1.

  FIG. 11 is a perspective view schematically showing a configuration example of a main part of a conventional wire saw device disclosed in Patent Document 1. As shown in FIG.

  As shown in FIG. 11, a conventional wire saw apparatus 100 mainly includes a fixed abrasive wire 101 for cutting a workpiece W, two grooved rollers 102 around which the fixed abrasive wire 101 is wound, and a fixed wire. Wire tension applying mechanisms 103A and 103B for applying tension to the abrasive wire 101, a workpiece feeding mechanism 104 for holding and cutting the workpiece W to be cut, and a cooling water supply for cooling the workpiece W to be cut And a mechanism 105.

  The fixed abrasive wire 101 is fed out from the supply bobbin 106A, and enters the grooved roller 102 through the wire tension applying mechanism 103A. The fixed abrasive wire 101 is wound around the grooved roller 102 about 300 to 400 times to form a wire row. The fixed abrasive wire 101 from another grooved roller 102 is wound around the recovery bobbin 106B via the other wire tension applying mechanism 103B.

  In this way, tension is applied to the fixed abrasive wire 101 wound around the grooved roller 102 by these wire tension applying mechanisms 103A and 103B, and a predetermined traveling time is set every predetermined reversal cycle time by the drive motor 107. It is traveling back and forth at speed. The workpiece W is pressed against the fixed abrasive wire 101 traveling in a reciprocating manner and cut and fed to cut the workpiece W into a number of wafers.

  In the conventional wire saw apparatus 100, the tension of the fixed abrasive wire 101 is managed by the wire tension applying mechanisms 103A and 103B on the new line supply side and the old line collection side.

JP 2011-20197 A

  In the conventional wire saw device 100 disclosed in Patent Document 1, a fixed abrasive wire 101 is used to cut a workpiece W, which is a semiconductor ingot, into a wafer shape by reciprocating wire movement.

   FIG. 12 shows wire tension fluctuation factors in a general wire saw device 100.

   FIG. 12A is a diagram schematically illustrating the tension monitoring result on the wire supply side with respect to the time axis (min), and FIG. 12B is a diagram schematically illustrating the wire traveling speed with respect to the time axis (min). is there.

As shown in FIGS. 12 (a) and 12 (b), in the wire saw device 100, (1) wire acceleration / deceleration at the time of reciprocating wire direction switching, (2) bobbin relative to the supply bobbin 106A and the recovery bobbin 106B Traverser folding when moving the fixed abrasive wire 101 in the width direction (it is difficult to follow by the traverser), (3) The fixed abrasive wire 101 is fed out and wound by causing the traverser to follow the supply bobbin 106A and the recovery bobbin 106B. The wire tension fluctuates due to the winding direction of the traverser around the bobbin when performing (4) inertia of the pulley and (5) wire vibration.
The tension fluctuation range at this time is as follows: (1) wire acceleration / deceleration and (4) pulley inertia of 15-20% in total, (2) 5-10% by traverser folding, 3) 15 to 20 percent due to tension fluctuation in the bobbin winding direction, and (5) 3 to 4 percent due to wire vibration.

  As specific tension fluctuation values, when the dancer roller tension set value is set to 13.5 N, (1) wire acceleration / deceleration, (4) tension fluctuation due to pulley inertia occurs ± 2.5 N, (2 ) Tension fluctuation due to traverser folding occurs ± 1N, (3) Tension fluctuation due to bobbin winding direction occurs ± 2.5N, (5) Tension fluctuation due to wire vibration occurs ± 0.5N It is confirmed that a tension fluctuation of ± 6.5 N occurs in total.

  In particular, the wire tension fluctuation has a great influence on (1) wire acceleration / deceleration, (2) traverser folding and (3) bobbin winding direction. When these multiple events occur at the same time, the wire tension fluctuation occurs. The maximum value exceeded T_max (20N in the figure), which is the breaking strength of the wire, and was the cause of wire breakage.

  Therefore, the workpiece W must be cut with a tension of 13.5 N or less obtained by subtracting the wire tension fluctuation (± 6.5 N) from the wire breaking strength (20 N).

  When the wire tension fluctuation becomes large and the fixed abrasive wire 101 is disconnected, the temperature state of the workpiece W or the wire saw device itself is lower than that immediately after the disconnection due to the time required for repairing the wire disconnection, and the cutting method is changed to cause a step. Therefore, there is a problem that both the workpiece W and the fixed abrasive wire 101 need to be exchanged.

  Conventionally, each of the dancer roller tensions of the wire tension applying mechanisms 103A and 103B has been controlled by a tension of about 60% of the wire breaking strength to prevent wire breakage. However, in recent thinning of the fixed abrasive wire 101, breakage When using the thin fixed abrasive wire 101 having low strength, if the dancer roller tension is lowered accordingly, there is a problem that the ability to cut the workpiece W is remarkably lowered and the cutting time is greatly increased.

  The present invention solves the above-described conventional problems, and is a wire saw device capable of efficiently cutting a workpiece without wire breakage even at a higher tension than the conventional device. (1) Wire acceleration / deceleration, (4) Tension fluctuation due to pulley inertia, (2) Tension fluctuation due to traverser folding, (3) Tension fluctuation due to bobbin winding direction, (5) Tension fluctuation due to wire vibration , (1) Wire acceleration / deceleration, (5) By providing a mechanism that does not exert tension fluctuations other than tension fluctuations due to wire vibration on the workpiece cutting area, it is possible to process tension fluctuations by further increasing the tension in the workpiece cutting area. Wire saw apparatus and workpiece cutting method using the same, and Solution 2 includes (1) wire acceleration / deceleration, which is a factor of tension fluctuation, and (4) pulley inertia (5) Tension fluctuation due to traverser folding, (3) Tension fluctuation due to bobbin winding direction, (5) Tension fluctuation due to wire vibration, (5) Tension fluctuation other than tension fluctuation due to wire vibration A wire saw device that can be processed by further increasing the tension at the time of cutting the workpiece by suppressing or preventing by the fluctuation absorbing means, a workpiece cutting method using the wire saw device, and a wire row of the wire saw device using this solution It is an object of the present invention to provide a wafer manufacturing method for manufacturing a wafer by cutting a plurality of wafers.

  In the wire saw device of the present invention, one end of a cutting wire wound between a plurality of grooved rollers arranged at a predetermined interval is wound around a supply bobbin via a first dancer roller, and the other end is second. In a wire saw device wound around a recovery bobbin via a dancer roller and reciprocatingly moving the wire to cut a workpiece by a plurality of rows of wires between the plurality of grooved rollers, the plurality of grooved rollers and the first dancer roller The first buffer bobbin means and the second buffer bobbin means are respectively disposed between the second dancer roller and the second dancer roller, and the third dancer roller is disposed between the plurality of grooved rollers and the first buffer bobbin means. And a fourth dancer roller is disposed between the plurality of grooved rollers and the second buffer bobbin means. Serial object is achieved.

  Preferably, in the wire saw device of the present invention, each tension value managed by the first dancer roller and the second dancer roller is lower than each tension value managed by the third dancer roller and the fourth dancer roller. Is set.

  Further preferably, in the wire saw device according to the present invention, the first buffer bobbin means and the second buffer bobbin means each have a tension fluctuation caused by a wire folding operation of the traverser with respect to the supply bobbin, and a wire folding of the traverser with respect to the recovery bobbin. The tension variation due to the operation has a wire winding length that does not affect each tension value managed by the third dancer roller and the fourth dancer roller.

  Further preferably, in the wire saw device according to the present invention, each tension value managed by the third dancer roller and the fourth dancer roller is greater than each tension value managed by the first dancer roller and the second dancer roller. It is set high within the range of the tension fluctuation value due to the wire folding operation.

  Further preferably, the tension values managed by the third dancer roller and the fourth dancer roller during the wire acceleration / deceleration accompanying the reciprocating switching of the wire travel in the wire saw device of the present invention are more than the respective tension values when the wire speed is constant. Each is set to a low setting.

  Further preferably, the workpiece feed amount is temporarily set to 0 during wire acceleration / deceleration accompanying reciprocal switching of wire travel in the wire saw device of the present invention.

  Further preferably, in the wire saw device of the present invention, each of the first buffer bobbin means and the second buffer bobbin means comprises one or a plurality of grooved rollers.

Further preferably, in the wire saw device of the present invention, a first traverser that moves following the wire winding position of the supply bobbin is provided between the supply bobbin and the first dancer roller, and the second dancer roller and the first dancer roller A second traverser that moves following the wire winding position of the recovery bobbin is provided between the recovery bobbins,
First wire tension fluctuation absorbing means for absorbing fluctuations in tension caused by wire folding movement of the first traverser relative to the supply bobbin and tension fluctuations caused by wire folding movement of the second traverser relative to the recovery bobbin; At least one of second wire tension fluctuation absorbing means for absorbing tension fluctuation at the time of acceleration / deceleration accompanying the acceleration / deceleration.

  Still preferably, in a wire saw device according to the present invention, the first traverser and the second traverser are each provided with the first wire tension fluctuation absorbing means.

  Further preferably, the first wire tension fluctuation absorbing means in the wire saw device of the present invention is disposed between the supply bobbin and the first traverser and between the recovery bobbin and the second traverser, respectively.

  Still preferably, in a wire saw device according to the present invention, the second wire tension fluctuation absorbing means is provided between each of the grooved roll and the first buffer bobbin means and the second buffer bobbin means, and the first buffer bobbin means. And at least one of the first traverser and the second buffer bobbin means and the second traverser.

  Further preferably, in the wire saw device of the present invention, each of the first wire tension fluctuation absorbing means and the second wire tension fluctuation absorbing means is provided such that each guide roller is rotatably provided at both ends of the plate body, A rotation shaft is provided between each guide roller, and each guide roller is rotatably supported around the rotation shaft, and the wire is passed through each guide roller so as to urge the wire in one rotation direction. In addition, tension applying means is provided so as to urge in the other rotation direction, and the urging force in the one rotation direction and the urging force in the other rotation direction are set in an equilibrium state.

  Further preferably, in the wire saw device of the present invention, the tension applying means applies the same tension to each guide roller as the tension by the first dancer roller and the second dancer roller, and each guide roller has the rotation shaft. It is in equilibrium as the center of rotation.

  In the workpiece cutting method of the present invention, one end of a cutting wire wound between a plurality of grooved rollers arranged at a predetermined interval is wound around a supply bobbin via a first dancer roller, and the other end is In a work cutting method in which a work is cut by a plurality of rows of wires between the plurality of grooved rollers by being wound around a recovery bobbin via two dancer rollers and reciprocating the wire, the plurality of grooved rollers and the first groove A first buffer bobbin means and a second buffer bobbin means are respectively disposed between the first dancer roller and the second dancer roller, and a third dancer roller is provided between the plurality of grooved rollers and the first buffer bobbin means. And a fourth dancer roller is disposed between the plurality of grooved rollers and the second buffer bobbin means. Serial object is achieved.

  Preferably, in the workpiece cutting method of the present invention, each tension value managed by the first dancer roller and the second dancer roller is lower than each tension value managed by the third dancer roller and the fourth dancer roller. Set to.

  Further preferably, in the workpiece cutting method according to the present invention, the first buffer bobbin means and the second buffer bobbin means each have a tension fluctuation due to a wire folding operation of the traverser with respect to the supply bobbin and a wire of the traverser with respect to the recovery bobbin. It has a wire winding length that does not affect each tension value managed by the third dancer roller and the fourth dancer roller with respect to tension fluctuation caused by the folding operation.

  Further preferably, in the work cutting method according to the present invention, each of the tension values managed by the third dancer roller and the fourth dancer roller is more than the tension values managed by the first dancer roller and the second dancer roller. Is set high within the range of the tension fluctuation value due to the wire folding operation.

  Further preferably, the tension values managed by the third dancer roller and the fourth dancer roller during the wire acceleration / deceleration associated with the reciprocating switching of the wire travel in the work cutting method of the present invention are determined from the tension values when the wire speed is constant. Are also controlled to be low.

  Further preferably, the workpiece feed amount is temporarily set to zero during wire acceleration / deceleration accompanying reciprocal switching of wire travel in the workpiece cutting method of the present invention.

  Further preferably, in the work cutting method of the present invention, each of the first buffer bobbin means and the second buffer bobbin means is composed of one or a plurality of grooved rollers.

  Further preferably, in the workpiece cutting method according to the present invention, a first traverser that moves the wire following the wire winding position of the supply bobbin is provided between the supply bobbin and the first dancer roller, and the second A second traverser that moves the wire following the wire winding position of the recovery bobbin is provided between the dancer roller and the recovery bobbin, and changes in tension due to the wire folding movement of the first traverser with respect to the supply bobbin and the recovery A first wire tension fluctuation absorbing means for absorbing a tension fluctuation due to a wire folding movement of the second traverser with respect to the bobbin; a second wire tension fluctuation absorbing means for absorbing a tension fluctuation at the time of acceleration / deceleration accompanying the reciprocating switching of the wire reciprocating travel; At least one of them.

  Further preferably, in the work cutting method according to the present invention, the first traverser and the second traverser are respectively provided with the first wire tension fluctuation absorbing means.

  Further preferably, the first wire tension fluctuation absorbing means in the work cutting method of the present invention is disposed between the supply bobbin and the first traverser and between the recovery bobbin and the second traverser, respectively.

  Still preferably, in a work cutting method according to the present invention, the second wire tension fluctuation absorbing means is provided between each of the grooved roll, the first buffer bobbin means, and the second buffer bobbin means, and the first buffer bobbin. Means and the first traverser and between the second buffer bobbin means and the second traverser.

  Further preferably, in the work cutting method according to the present invention, each of the first wire tension fluctuation absorbing means and the second wire tension fluctuation absorbing means is provided such that each guide roller is rotatably provided at both ends of the belt-like plate body. A rotation shaft is provided between the guide rollers, the guide rollers are rotatably supported around the rotation shaft, and the wire is urged to the guide rollers in one rotation direction. The tension applying means is provided so as to urge in the other rotation direction, and the urging force in the one rotation direction and the urging force in the other rotation direction are set in an equilibrium state.

  Still preferably, in a work cutting method according to the present invention, the tension applying means applies the same tension to the guide rollers as the tensions by the first dancer roller and the second dancer roller, and applies the guide rollers to the rotating shaft. Equilibrium around the center of rotation.

  The wafer manufacturing method of the present invention is the above-described workpiece cutting method of the present invention, wherein the workpiece is a semiconductor ingot, and the semiconductor ingot is cut into a plurality of wafers by a wire row of a wire saw device. The material is manufactured, and the above object is achieved thereby.

  With the above configuration, the operation of the present invention will be described below.

  In the present invention, one end of a cutting wire wound between a plurality of grooved rollers arranged at a predetermined interval is wound around a supply bobbin via a first dancer roller, and the other end is connected to a second dancer roller. In a wire saw device that is wound around a recovery bobbin to reciprocate a wire and cut a workpiece by a plurality of rows of wires between the plurality of grooved rollers, a plurality of grooved rollers, a first dancer roller, and a second dancer roller A first buffer bobbin means and a second buffer bobbin means are respectively disposed therebetween, a third dancer roller is disposed between the plurality of grooved rollers and the first buffer bobbin means, and a plurality of grooved A fourth dancer roller is disposed between the roller and the second buffer bobbin means.

  As a result, with respect to the wire tension of the cutting area where the workpiece is cut, the buffer bobbin is not affected by the fluctuation of the wire tension due to the bobbin turning back where the tension fluctuation is large, and the wire tension of the cutting area is set to be increased accordingly. Since the wire tension can be set small in the region where the wire tension fluctuation due to bobbin folding exists, it is possible to efficiently cut the workpiece with higher wire tension in the cutting region compared to the conventional device. Wire tension due to bobbin folding In the region where the fluctuation exists, the wire tension can be weakened to suppress or prevent the wire breakage. In short, even if the wire tension is weakened in the region where the wire tension fluctuation due to bobbin folding exists, the wire tension is increased by that much in the cutting area where the buffer bobbin is not affected by the wire tension fluctuation due to bobbin folding. Can be performed.

  As described above, according to the present invention, the wire tension in the cutting region where the workpiece is cut is not affected by the buffer bobbin due to the bobbin wrapping with a large tension variation, and the wire tension in the cutting region is reduced. Since the wire tension can be set small in the region where the wire tension fluctuation due to bobbin folding exists, the workpiece can be cut efficiently with higher wire tension than the conventional device in the cutting region. In a region where wire tension fluctuation due to bobbin folding exists, the wire tension can be weakened to suppress or prevent wire breakage.

It is a perspective view which shows typically the example of a principal part structure of the wire saw apparatus in Embodiment 1 of this invention. (A) is a diagram schematically showing the tension monitoring result on the wire supply side with respect to the time axis (min), (b) is a diagram schematically showing the wire traveling speed with respect to the time axis (min), and (c) is a diagram. It is a figure which shows typically the tension monitoring result of the wire cutting area | region with respect to a time-axis (min). It is a perspective view which shows typically the example of a principal part structure of the wire saw apparatus in Embodiment 2 of this invention. It is a front view which shows an example of the 1st wire tension | tensile_strength fluctuation | variation absorption means of the traverser of FIG. It is a side view which shows the example different from the 1st wire tension | tensile_strength fluctuation | variation absorption means of FIG. It is a front view of the 1st wire tension fluctuation | variation absorption means of FIG. It is a front view which shows the example of the 2nd wire tension | tensile_strength fluctuation | variation absorption means different from the 1st wire tension | tensile_strength absorption means of FIG. It is a front view containing the 2nd tension | tensile_strength fluctuation | variation absorption means of another example from the 2nd tension | tensile_strength absorption means of FIG. (A) is a diagram schematically showing the tension monitoring result on the wire supply side with respect to the time axis (min), (b) is a diagram schematically showing the wire traveling speed with respect to the time axis (min), and (c) is a diagram. It is a figure which shows typically the tension monitoring result of the wire cutting area | region with respect to a time-axis (min). (A) is a diagram schematically showing the tension monitoring result on the wire supply side with respect to the time axis (min), (b) is a diagram schematically showing the wire traveling speed with respect to the time axis (min), and (c) is a diagram. It is a figure which shows typically the tension monitoring result of the wire cutting area | region with respect to a time-axis (min). It is a perspective view which shows typically the example of a principal part structure of the conventional wire saw apparatus currently disclosed by patent document 1. FIG. (A) is a figure which shows typically the tension | tensile_strength monitoring result by the side of the wire supply with respect to time-axis (min), (b) is a figure which shows typically the wire travel speed with respect to time-axis (min).

  Embodiments 1 and 2 of a wire saw device, a workpiece cutting method, and a wafer manufacturing method of the present invention will be described below in detail with reference to the drawings. In addition, each thickness, length, etc. of the structural member in each figure are not limited to the structure to illustrate from a viewpoint on drawing preparation.

(Embodiment 1)
FIG. 1 is a perspective view schematically showing a configuration example of a main part of a wire saw device according to Embodiment 1 of the present invention.

  In FIG. 1, a wire saw device 1 according to the first embodiment has a plurality of (here, two) grooved rollers 2 and 3 arranged horizontally at a predetermined interval. The rotating shafts of the two grooved rollers 2 and 3 are parallel to each other in the axial direction, and are rotatably provided with an outer peripheral groove outside the rotating shaft. Each of the grooved rollers 2 and 3 has a plurality of outer peripheral grooves formed at predetermined pitch intervals on the peripheral surface thereof. A cutting wire 4 is wound around the outer peripheral grooves of the plurality of grooved rollers 2 and 3 arranged at a predetermined interval.

  The wire 4 wound around the outer peripheral grooves of the grooved rollers 2 and 3 is wound spirally. When the number of windings between the grooved rollers 2 and 3 is large, the number is several thousand. One end of the wire 4 wound spirally between the grooved rollers 2 and 3 is wound around the supply bobbin 5 on the new line supply side, and the other end is wound around the recovery bobbin 6 on the old line collection side. By driving the grooved rollers 2 and 3, the supply bobbin 5 and the recovery bobbin 6 in synchronization with each other, the wire 4 wound between the grooved rollers 2 and 3 is caused to travel so that a plurality of rows of the wires 4 are driven. A large number of workpieces 7 (here, semiconductor ingots) are cut simultaneously. When there are many cut sheets, several thousand sheets are cut simultaneously. The wire 4 has a core wire diameter of about 50 μm to 500 μm, for example, and a fixed abrasive wire in which abrasive grains such as diamond are fixed around the core wire. For example, when the diameter of the wire 4 is 50 μm (0.05 mm), the cutting margin is ideally about 50 μm (0.05 mm). For example, a wire 4 of several tens to several hundreds Km is wound around the supply bobbin 5. The wire saw device 1 reciprocates along the wire 4, and the wire 4 wound around the recovery bobbin 6 operates as a supply bobbin by inverting the driving of the grooved rollers 2 and 3, the supply bobbin 5 and the recovery bobbin 6. Here, the supply bobbin 5 and the recovery bobbin 6 are described with their names determined.

  In order to give a required tension to the wire 4 wound around each grooved roller 2, 3, inertia driven guide rollers 8, 9 are provided between the grooved roller 2 and the supply bobbin 5. A first dancer roller 10 is provided therebetween. Similarly, in order to give a required tension, inertia driven guide rollers 11 and 12 between the grooved roller 2 and the recovery bobbin 6 are provided, and a second dancer roller 13 is provided between the guide rollers 11 and 12. ing. A buffer bobbin 14 that rotates in synchronization with the wire travel is provided between the grooved roller 2 and the guide roller 9, and inertia driven guide rollers 15 and 16 are provided between the grooved roller 2 and the buffer bobbin 14. A third dancer roller 17 is provided between the guide rollers 15 and 16 to provide the required tension. Similarly, a buffer bobbin 18 that rotates in synchronization with the wire travel is provided between the grooved roller 2 and the guide roller 11, and inertia driven guide rollers 19, 20 are provided between the grooved roller 2 and the buffer bobbin 18. And a fourth dancer roller 21 is provided between the guide rollers 19 and 20 in order to give a required tension.

  Each of the buffer bobbins 14 and 18 is for buffering so that the wire 4 can go around several hundred meters and the tension on the grooved rollers 2 and 3 side and the tension on the supply bobbin 5 or the recovery bobbin 6 side do not affect each other. Is provided. Here, the winding length of the wire 4 around the buffer bobbins 14 and 18 is set to a length that is not affected by the tension before and after the bobbin (for example, 200 m to 300 m), so that the wires 4 do not overlap and there is no wire friction. Like that. Each of the buffer bobbins 14 and 18 may have one bobbin configuration, two bobbin configurations, or a plurality of bobbin configurations beyond that. For example, in the case of two bobbin configurations as the buffer bobbin 14, the number of turns of the wire 4 can be reduced and the distance of the wire 4 can be increased as compared with one bobbin configuration. The buffer bobbins 14 and 18 may or may not have grooves, but the wire 4 need not slip. Further, the buffer bobbins 14 and 18 are rotated so as to be synchronized with the rotational driving of the grooved rollers 2 and 3, respectively. Accordingly, the tension fluctuation between the supply bobbin 5 and the buffer bobbin 14 and the tension fluctuation between the buffer bobbin 18 and the recovery bobbin 6 are separated, and the tension fluctuation between the buffer bobbins 14 and 18 and the grooved rollers 2 and 3 are separated into separate dancer rollers. 10 and 13 and dancer rollers 17 and 21. The position A on the grooved rollers 2 and 3 side of the buffer bobbins 14 and 18 is prevented from being always transmitted with the tension change due to the wire folding by the traversers 22 and 23 described later.

  The first dancer roller 10 controls the tension of the wire 4 between the supply bobbin 5 and the buffer bobbin 14 to be constant. The second dancer roller 13 controls the tension of the wire 4 between the buffer bobbin 14 and the recovery bobbin 6 to be constant. The third dancer roller 17 controls the tension of the wire 4 between the buffer bobbin 14 and the grooved roller 2 to be constant. Further, the fourth dancer roller 21 controls the tension of the wire 4 between the grooved roller 2 and the buffer bobbin 18 to be constant. These dancer rollers 10, 13, 17, and 21 are configured so that a constant urging force acts downward and a constant tension acts on the wire 4. The tension values managed by the third dancer roller 17 and the fourth dancer roller 21 are set higher than the tension values managed by the first dancer roller 10 and the second dancer roller 13. In short, the tension of the cutting region 31 for cutting the workpiece 7 can be increased by the amount that the fluctuation in tension due to the wire folding does not affect the cutting region 31 side by the buffer bobbins 14 and 18, and the supply region 32 or the recovery bobbin 6 on the supply bobbin 5 side. The side recovery area 33 is managed with a lower tension. Each tension in the supply area 32 and the collection area 33 is preferably 3.5 N or more lower than the tension in the cutting area 31 of the workpiece 7. This is because the supply region 32 and the recovery region 33 are (1) wire acceleration / deceleration, (4) tension variation due to pulley inertia, (2) tension variation due to traverser folding, (3) tension variation due to bobbin winding direction, ( 5) An area affected by fluctuations in tension due to wire vibration, and the workpiece cutting area 31 is (1) wire acceleration / deceleration, (4) tension fluctuation due to pulley inertia, and (5) influence of tension fluctuation due to wire vibration. By controlling with a tension lower than 3.5N, which is the difference between these, even if multiple tension fluctuation events occur simultaneously, the breaking strength of the wire is not exceeded and wire breakage is prevented. can do.

  Specifically, in the workpiece cutting region 31 where the workpiece 7 is cut, the tension is controlled at 17 N by the third dancer roller 17 and the fourth dancer roller 21, and the third dancer roller 17 and the fourth dancer roller 21 at the time of acceleration / deceleration of the wire reciprocating travel. In order to prevent the wire 4 from being disconnected, the tension is controlled at 13.5N, which is 3.5N lower than 17N. In this way, during acceleration / deceleration of the wire reciprocation, the tension control value of the third dancer roller 17 and the fourth dancer roller 21 for controlling the tension of the grooved rollers 2 and 3 is set in order to prevent the wire 4 from being disconnected due to the tension fluctuation. Lower. The control tension value is decreased as the wire travel starts decelerating, the control tension value is minimized when the travel is stopped (travel speed is 0), and the control tension value is increased as the wire travel starts. At the same time, if the feeding of the workpiece 7 is also temporarily stopped, it is effective to prevent the wire 4 from being disconnected at the third dancer roller 17 and the fourth dancer roller 21. On the other hand, in the supply area 32 on the supply bobbin 5 side and the recovery area 33 on the recovery bobbin 6 side, the tension is controlled by 10 N by the first dancer roller 10 and the second dancer roller 13. The control tension values of the first dancer roller 10 and the second dancer roller 13 are set to be lower than the control tension values of the third dancer roller 17 and the fourth dancer roller 21 by the traversers 22 and 23 and below the amount of wire tension fluctuation caused by the wire folding. .

  A traverser 22 is provided between the supply bobbin 5 and the guide roller 8 so that the traverser 22 moves in the bobbin width direction of the supply bobbin 5 so that the wires 4 aligned and wound around the supply bobbin 5 are sequentially taken out. Works. A traverser 23 is provided between the guide roller 12 and the recovery bobbin 6 so that the traverser 23 moves in the bobbin width direction of the recovery bobbin 6 and is aligned with the recovery bobbin 6 so that the wire 4 is wound up. Works. In this case, the traverser 22 on the supply side has a function of smoothly moving to the bobbin wire position when the wire 4 is taken in from the supply bobbin 5 and smoothly taking out the aligned and wound wire 4. Further, the traverser 23 on the collection side has a function of sequentially moving to the bobbin wire position and winding the wires 4 smoothly and sequentially in order to wind the wires 4 around the collection bobbins 6.

  The upper wire row surface of the wire 4 between the grooved rollers 2 and 3 is a cut surface of the work 7 of the semiconductor ingot, and the processing liquid supply parts 24 and 25 are provided in front of and behind the work 7 so as to cross the cut surface left and right. It has been. For example, the workpiece 7 is pressed against the wire row surface of the cut surface and cut while applying cooling coolant to the wire rows of the cut surface from the machining liquid supply ports of the machining liquid supply units 24 and 25. While cooling liquid coolant is applied to the workpiece 7 and each wire 4 for the purpose of cooling, the workpiece 7 is simultaneously cut into a plurality of wafers by the multiple wires 4.

  For pressing the workpiece 7 against the wire row, the fixing portion 26 to which the workpiece 7 is fixed is moved up and down by the workpiece feeding mechanism 27, and the workpiece 7 is pressed against the wire row between the grooved rollers 2 and 3 from above. By pressing the workpieces 7 on a plurality of rows of wires 4 in which a large number of wires are arranged in parallel, a plurality of thin wafers having a uniform thickness are simultaneously cut. As a result, a wafer material having a uniform thickness can be manufactured.

  The operation of the above configuration will be described below.

  FIG. 2A is a diagram schematically showing the tension monitoring result on the wire supply side with respect to the time axis (min), FIG. 2B is a diagram schematically showing the wire traveling speed with respect to the time axis (min), FIG.2 (c) is a figure which shows typically the tension | tensile_strength monitoring result of the wire cutting area | region 31 with respect to the time-axis (min).

  As described above, the causes of wire tension fluctuation are mainly (1) wire acceleration / deceleration, (4) tension fluctuation due to pulley inertia, (2) tension fluctuation due to traverser folding, (3) tension fluctuation due to bobbin winding direction, and (5) Tension fluctuation due to wire vibration.

  As shown in FIG. 2A, the wire tension fluctuates in a ± 1N split mountain shape and a valley shape, for example, centering on a tension of 13.5N in the wire turn-back cycle by the traversers 22 and 23. In addition, a trigger-like tension fluctuation of ± 2.5 N is generated by the acceleration / deceleration accompanying the reciprocating travel of the wire. Further, a tension fluctuation of ± 2.5 N occurs due to a tension fluctuation depending on the winding direction of the supply bobbin 5 and the recovery bobbin 6.

  As shown in FIG. 2B, the workpiece 7 is cut into a number of wafers by reciprocating wire movement, but the wire 4 is accelerated and decelerated from a predetermined constant speed when the direction of the reciprocating wire is switched. The forward traveling and the backward traveling of the wire 4 have a time ratio of about 1000 to 990.

  As shown in FIG. 2A, the wire tension is increased or decreased in a trigger-like manner at a position around the wire speed 0 at the time of wire acceleration / deceleration accompanying reciprocal switching of wire travel. Therefore, the influence of fluctuations in the wire tension is large. The supply bobbins of the traversers 22 and 23 when the traversers 22 and 23 follow the supply bobbins 5 and the recovery bobbins 6 and the fixed abrasive wire 4 is fed and wound. 5 and when the tension fluctuation due to the winding direction to the recovery bobbin 6 is maximum, the maximum value of the wire tension fluctuation due to the wire folding operation by the traversers 22 and 23 overlaps, and the wire tension fluctuation due to the wire acceleration / deceleration during the reciprocating movement of the wire Wire tension fluctuations are maximized when they occur simultaneously. This is the maximum tension position T max indicated by the arrow in the left lateral direction in FIG. This maximum tension must not exceed the breaking tension 20N of the wire 4.

  In the first embodiment, buffer bobbins 14 and 18 are provided between a workpiece cutting area 31 where the workpiece 7 is cut, a supply area 32 on the supply bobbin 5 side, and a recovery area 33 on the recovery bobbin 6 side. The wire tension of 31 is not affected by the fluctuation of the wire tension due to the wire folding operation of the traversers 22 and 23 having a large fluctuation of the wire tension. The maximum value of the wire tension is lowered by the amount that the wire tension fluctuation due to the wire folding operation of the traversers 22 and 23 is not transmitted to the workpiece cutting area 31 by the buffer bobbins 14 and 18. On the contrary, even if the wire tension is increased, the wire 4 is not broken and the workpiece 7 can be cut efficiently because the maximum value of the wire tension is lowered in the workpiece cutting region 31.

  Therefore, in the workpiece cutting region 31 sandwiched between the buffer bobbins 14 and 18, the wire tension fluctuation increases or decreases in a trigger shape due to the wire acceleration / deceleration at the time of reciprocating wire direction switching, but with respect to the supply bobbin 5 and the recovery bobbin 6. Then, the traversers 22 and 23 are caused to follow, the fixed abrasive wire 101 is fed out, and the tension variation due to the winding direction of the traversers 22 and 23 around the supply bobbin 5 and the recovery bobbin 6 when winding is performed, and the supply bobbin 5 and the recovery bobbin 6 On the other hand, when the wire 4 is moved in the bobbin width direction, the wire tension does not fluctuate due to the wire folding operation, and the corrugated waveform of the mountain shape and the valley shape shown in FIG. As shown in the figure, it becomes a horizontal single line with only the trigger-like tension fluctuations shown periodically, Variation is not divided, it is possible to increase the efficiency of cutting by increasing the tension.

  In short, the tension values managed by the third dancer roller 17 and the fourth dancer roller 21 are different from the tension values managed by the first dancer roller 10 and the second dancer roller 13, and the tension fluctuation values due to the wire folding operation of the traversers 22 and 23. It may be set high within the range.

  On the other hand, in the supply region 32 on the supply bobbin 5 side and the recovery region 33 on the recovery bobbin 6 side that are isolated by the buffer bobbins 14 and 18, as shown in FIG. The supply bobbin together with the tension variation (for example, 2.5 N) depending on the winding direction of the supply bobbin 5 and the recovery bobbin 6 of the traverser 22 and 23 when the traversers 22 and 23 are caused to follow and the fixed abrasive wire 101 is fed and wound. 5 or fluctuations in wire tension due to wire wrapping when the wire 4 is moved in the bobbin width direction with respect to the recovery bobbin 6 (for example, 1 N). Wire tension fluctuation (for example, 2.5 N) and tension fluctuation (for example, 0.5 N) due to wire vibration occur, By lowering the tension value can be ensured the safety of the breakage of the wire 4.

  As described above, according to the first embodiment, one end of the cutting wire 4 wound between the grooved rollers 2 and 3 arranged at a predetermined interval is connected to the supply bobbin 5 via the first dancer roller 10. The other end of the cutting wire 4 wound between the grooved rollers 2 and 3 is wound around the recovery bobbin 6 via the second dancer roller 13, and the wire 4 travels to cause each grooved roller 2 to run. , 3, the wire saw device 1 that cuts the workpiece 7 with a plurality of rows of wires 4, each grooved roller 2, 3 between the first dancer roller 10 and the second dancer roller 13 as a first buffer bobbin means, respectively. A first buffer bobbin 14 and a second buffer bobbin 18 as a second buffer bobbin means are respectively disposed, and a third damper bobbin 18 is provided between each grooved roller 2, 3 and the first buffer bobbin 14. With roller 17 is arranged, a fourth dancer rollers 21 are disposed between the respective grooved rollers 2 and the second buffer bobbin 18.

  As a result, the first buffer bobbin 14 and the second buffer bobbin 18 are provided so that the wire tension of the region 31 where the work 7 is cut, such as a semiconductor ingot, is not affected by the bobbin folding, which is a cause of large fluctuations in the wire tension. The tension on each grooved roller 2 and 3 side can be set to the maximum by the tension fluctuation at the time of bobbin folding, and cutting of workpieces 7 such as semiconductor ingots without wire breakage with higher wire tension than conventional devices Can be performed efficiently.

  That is, the wire tension in the wire cutting region 31 that cuts the workpiece 7 is not affected by the buffer bobbins 14 and 18 due to the wire tension fluctuation caused by the bobbin folding operation with large tension fluctuation. Is set to be larger by that amount, and the wire tension can be set smaller in the supply region 32 and the recovery region 33 where the wire tension fluctuation due to the bobbin folding operation exists, so that the wire cutting region 31 has a higher wire tension than the conventional device. The workpiece 7 can be efficiently cut, and the wire tension can be weakened to suppress or prevent the wire breakage in the region where the wire tension fluctuation due to the bobbin folding operation exists (supply region 32 and recovery region 33).

(Embodiment 2)
In the first embodiment, the buffer bobbin 14 is provided between the grooved roller 2, the supply bobbin 5 and the traverser 22, and the buffer bobbin 18 is provided between the grooved roller 2, the traverser 23, and the recovery bobbin 6. Although the case where the bobbin 14 or 18 does not affect the wire tension fluctuation caused by the wire turnback by the traverser on the workpiece cutting area on the grooved rollers 2 and 3 side has been described, in the second embodiment, the wire turnback by the traverser is the cause. The case where the wire tension fluctuation to be absorbed is absorbed by the tension fluctuation absorbing means as the tension fluctuation absorbing mechanism will be described.

  FIG. 3 is a perspective view schematically showing a configuration example of a main part of a wire saw device according to Embodiment 2 of the present invention. In FIG. 3, the same reference numerals are given to the components having the same operational effects as the components of FIG. 1.

  In FIG. 3, in the wire saw device 1 </ b> A according to the first embodiment, each of the grooved rollers 2 and 3 disposed at a predetermined distance is formed with a plurality of outer peripheral grooves at predetermined pitch intervals on the peripheral surface thereof. A cutting wire 4 is wound around the outer peripheral grooves of the plurality of grooved rollers 2 and 3. One end of the wire 4 spirally wound between the grooved rollers 2 and 3 is wound around the supply bobbin 5 on the new line supply side from the grooved roller 2, and the other end is recovered from the grooved roller 2 at the other end. It is wound around the recovery bobbin 6 on the side. By driving the supply bobbin 5 and the recovery bobbin 6, the wire 4 wound between the grooved rollers 2 and 3 is caused to travel so that a plurality of workpieces 7 (here, semiconductor ingots) are simultaneously formed in a plurality of rows of the wires 4. It is designed to cut.

  A first dancer roller 10 is provided between the grooved roller 2 and the supply bobbin 5 in order to give a required tension to the wire 4 wound around each grooved roller 2, 3. A second dancer roller 13 is provided. A traverser 22A having a tension fluctuation absorbing means is provided between the first dancer roller 10 and the supply bobbin 5, and the traverser 22A follows the wire winding position of the supply bobbin 5 and moves in the bobbin width direction. The wire 4 wound in alignment with the wire 5 acts so as to be sequentially taken out. Further, a traverser 23A having a tension fluctuation absorbing means is also provided between the second dancer roller 13 and the recovery bobbin 6, and the traverser 23A moves in the bobbin width direction following the wire winding position of the recovery bobbin 6, The wire 4 is wound up in alignment with the recovery bobbin 6. In this case, the supply-side traverser 22A has a function of smoothly taking out the aligned and wound wires 4 by sequentially moving to the bobbin wire position when the wires 4 are taken in from the supply bobbin 5. Further, the recovery-side traverser 23A has a function of sequentially moving to the bobbin wire position and winding the wire 4 smoothly and sequentially in order to wind the wire 4 around the recovery bobbin 6.

  The tension fluctuation absorbing means of the traversers 22A and 23A respectively absorbs the tension fluctuation generated in the wire folding operation when the wire 4 is moved in the bobbin width direction with respect to the supply bobbin 5 and the recovery bobbin 6, respectively. Absorbing means.

  Although the upper wire row surface of the wire 4 between the grooved rollers 2 and 3 is a cut surface of the work 7, although not shown here, the machining liquid supply units 24 and 25 cross the cut surface left and right. It is provided before and after the workpiece 7. The workpiece 7 is pressed against the wire row by moving the fixing portion 26 fixing the workpiece 7 up and down by the workpiece feeding mechanism 27 and pressing the workpiece 7 against the wire row between the grooved rollers 2 and 3 from above. . These configurations are the same as those in FIG.

  4 is a front view showing an example of the first wire tension fluctuation absorbing means of the traverser 22A of FIG. The first wire tension fluctuation absorbing means of the traverser 22A has the same configuration as the first wire tension fluctuation absorbing means of the traverser 23A.

  As shown in FIG. 4, in the first wire tension fluctuation absorbing means of the traverser 22A, the guide rollers 221 and 222 are rotatably provided at both ends of the belt-like plate body, and rotate between the guide rollers 221 and 222. A shaft 223 is provided, and the guide rollers 221 and 222 are rotatably supported around the rotation shaft 223 as a rotation center. The first wire tension fluctuation absorbing means of the traverser 22A is passed through each guide roller 221 and 222 in an S shape so that the wire 4 is biased in one rotation direction, and the tension applying means is biased in the other rotation direction. (Rotation urging means) is provided so that the urging force in one rotation direction and the urging force in the other rotation direction are in an equilibrium state (equilibrium state).

  That is, in the first wire tension fluctuation absorbing means of the traverser 22A, the guide rollers 221 and 222 are pivotally supported around the rotation shaft 223 at both ends of the belt-like plate body, and are not shown here. There is tension applying means (rotating urging means) such as a helical spring and a rotating solenoid coil that urges the rotating shaft 223 as a center of rotation with a predetermined urging force (tension setting value of the dancer roller) in the left rotation direction. The biasing force of a spring or the like is adjusted so that the seesaw-like tension fluctuation absorbing means having the rotation shaft 223 is balanced with the tension setting values of the dancer rollers 10 and 13. In this way, the wire 4 extends from the right side of the guide roller 221 so that the two guide rollers 221 and 222 are balanced in a seesaw shape with the rotation shaft 223 therebetween being urged in the left rotation direction. The wire 4 is drawn out to the right side through the guide roller 222 after being passed in an S shape on the left side.

  In this case, when the tension of the wire 4 gradually or instantaneously increases and the wire 4 is pulled to the right, the counterclockwise direction of the tension applying means (rotating biasing means) counteracts the counterclockwise biasing force. The tension fluctuation is absorbed by rotating in the direction. Conversely, even if the tension of the wire 4 gradually or instantaneously decreases and the wire 4 loosens and moves to the left, the seesaw balance with the counterclockwise biasing force of the tension applying means (rotating biasing means). When the guide rollers 221 and 222 rotate around the rotation shaft 223 in the counterclockwise direction by the urging force of the tension applying means (rotation urging means) and the wire 4 is loosened, the loosened portion of the wire 4 can be absorbed.

  The traverser 22A moves in the bobbin width direction (traverser reciprocation range B) of the supply bobbin 5 together with the first wire tension fluctuation absorbing means, and the wires 4 wound in alignment with the supply bobbin 5 are sequentially taken out.

  FIG. 4 illustrates the case where the first wire tension fluctuation absorbing means is provided in each of the first traverser 22A and the second traverser 23A. However, in FIG. 5 and FIG. A case will be described in which the means are arranged between the supply bobbin 5 and the recovery bobbin 6 and the traverser.

  FIG. 5 is a side view showing an example different from the first wire tension fluctuation absorbing means of FIG. FIG. 6 is a front view of the first wire tension fluctuation absorbing means of FIG.

  As shown in FIGS. 5 and 6, the first wire tension that absorbs each fluctuation in tension caused by the relative position fluctuation between the supply bobbin 5 and one traverser 22B and the relative position fluctuation between the recovery bobbin 6 and the other traverser 23B. A tension fluctuation absorbing means 225 as a fluctuation absorbing means is disposed between the supply bobbin 5 and the traverser 22B and between the recovery bobbin 6 and the traverser 23B. Here, the tension fluctuation absorbing means 225 as the first wire tension fluctuation absorbing means provided between the supply bobbin 5 and the traverser 22B will be described. In this tension fluctuation absorbing means 225, the guide rollers 221 and 222 provided at both ends of the belt-like plate body are rotatably supported around the rotation shaft 223 therebetween, and are directly connected by the belt-like plate body. The guide rollers 221 and 222 themselves are also rotatably supported. The rotary shaft 223 is urged in the clockwise direction by a predetermined urging force of the spring 224 (same as the tension setting value of the dancer roller 10) in the right rotation direction. The wire 4 is inverted S-shaped from the left side of the guide roller 221 to the right side of the guide roller 222 so that the tension fluctuation absorbing means 225 is biased in the clockwise direction by the spring 224 and is balanced in a seesaw shape with the rotation shaft 223 as the rotation center. Then, the wire 4 is drawn from the guide roller 222 through the traverser 22B. The left rotational force by the first dancer roller 10 that applies tension to the wire 4 and the right rotational force by the biasing force of the spring 224 that applies the same tension as the dancer roller 10 are balanced in a seesaw shape.

  In this case, when the tension of the wire 4 gradually or instantaneously increases and the wire 4 is pulled, the tension fluctuation absorbing means 225 rotates counterclockwise against the biasing force of the spring 224 in the clockwise direction. As a result, the tension fluctuation is absorbed. Conversely, even if the tension of the wire 4 gradually or instantaneously decreases and the wire 4 is loosened, the seesaw balance with the urging force of the spring 224 in the clockwise direction is lost, and the urging force of the spring 224 causes it to rotate in the clockwise direction. As the guide rollers 221 and 222 rotate around the rotation shaft 223, the loosened portion of the wire 4 can be absorbed.

  FIG. 7 is a front view showing an example of second wire tension fluctuation absorbing means different from the first wire tension fluctuation absorbing means of FIG.

  As shown in FIG. 7, the traverser 22 </ b> C is provided with a tension fluctuation absorbing means as a second wire tension fluctuation absorbing means for absorbing a tension fluctuation during acceleration / deceleration accompanying switching of the reciprocating travel of the wire 4. The second wire tension fluctuation absorbing means of the traverser 22C is disposed on the dancer roller 10 side. In this traverser 22C, guide rollers 221 and 222 provided at both ends of a belt-like plate body are rotatably supported around a rotation shaft 223 therebetween, and each guide roller is directly connected by the belt-like plate body. 221 and 222 themselves are also rotatably supported. The guide rollers 221 and 222 are rotated in the clockwise direction with the rotation shaft 223 as the center of rotation, and urged by a predetermined urging force (same as the tension setting value of the dancer roller 10) of the spring 224 as tension applying means (rotating urging means). Has been. After the wire 4 is passed in a reverse S-shape from the left side of the guide roller 221 to the lower side of the guide roller 222 so that the guide rollers 221 and 222 are balanced in a state of being urged in the clockwise direction by the spring 224, The wire 4 is pulled out from the guide roller 222. The left rotational force by the dancer roller 10 that applies tension to the wire 4 and the right rotational force by the biasing force of the spring 224 that applies the same tension as the dancer roller 10 are balanced in a seesaw shape.

  In this case, when the tension of the wire 4 gradually or instantaneously increases and the wire 4 is pulled, the tension fluctuation is absorbed by rotating in the counterclockwise direction against the urging force of the spring 224 in the clockwise direction. Is done. Conversely, even if the tension of the wire 4 gradually or instantaneously decreases and the wire 4 is loosened, the balance with the biasing force of the spring 224 in the clockwise rotation direction is lost, and the biasing force of the spring 224 guides it in the clockwise rotation direction. As the rollers 221 and 222 rotate around the rotation shaft 223, the loosened portion of the wire 4 can be absorbed.

  FIG. 8 is a front view including the second tension fluctuation absorbing means in another case different from the second tension fluctuation absorbing means of FIG.

  As shown in FIG. 8, the tension fluctuation absorbing means 225 as the first wire tension fluctuation absorbing means for absorbing the tension fluctuation caused by the relative position fluctuation between the supply bobbin 5 and one traverser 22B includes the supply bobbin 5 and the traverser 22B. It is arranged between. Further, a tension fluctuation absorbing means 226 as a second wire tension fluctuation absorbing means for absorbing a tension fluctuation at the time of acceleration / deceleration accompanying switching of the reciprocating travel of the wire 4 is provided between the traverser 22B and the dancer roller 10. In short, the tension fluctuation absorbing means 225 as the first wire tension fluctuation absorbing means and the tension fluctuation absorbing means 226 as the second wire tension fluctuation absorbing means are provided together with the traverser 22B (or traverser 23B) in between.

  In this tension fluctuation absorbing means 225, the guide rollers 221 and 222 provided at both ends of the belt-like plate body are rotatably supported around the rotation shaft 223 therebetween, and are directly connected by the belt-like plate body. The guide guide rollers 221 and 222 are also rotatably supported on the shaft. Each guide guide roller 221, 222 is rotated in the clockwise direction around the rotation shaft 223 by a predetermined urging force (same as the tension setting value of the dancer roller 10) of a spring 224 as a tension applying means (rotating urging means). It is energized. After the wire 4 is passed in a reverse S-shape from the left side of the guide roller 221 to the right side of the guide roller 222 so that the tension fluctuation absorbing means 225 is balanced in a seesaw shape with the spring 224 biased in the clockwise direction. The wire 4 is drawn from the guide roller 222 via the traverser 22B. The left rotational force by the dancer roller 10 that applies tension to the wire 4 and the right rotational force by the biasing force of the spring 224 that applies the same tension as the dancer roller 10 are balanced in a seesaw shape.

  In this case, when the tension of the wire 4 gradually or instantaneously increases and the wire 4 is pulled, the tension fluctuation absorbing means 225 rotates counterclockwise against the biasing force of the spring 224 in the clockwise direction. As a result, the tension fluctuation is absorbed. Conversely, even if the tension of the wire 4 gradually or instantaneously decreases and the wire 4 is loosened, the balance with the biasing force of the spring 224 in the clockwise rotation direction is lost, and the biasing force of the spring 224 guides it in the clockwise rotation direction. As the rollers 221 and 222 rotate around the rotation shaft 223, the loosened portion of the wire 4 can be absorbed.

  Next, the tension fluctuation absorbing means 226 is such that guide rollers 221 and 222 provided at both ends of the belt-like plate body are rotatably supported around the rotation shaft 223 therebetween, and are directly connected by the belt-like plate body. The guide rollers 221 and 222 themselves are also rotatably supported. The rotary shaft 223 is urged in the clockwise direction with a predetermined urging force (same as the tension setting value of the dancer roller 10) of the spring 224 as the tension applying means (rotating urging means) in the right rotation direction. After the wire 4 is passed in an inverted S shape from the left side of the guide roller 221 to the lower side of the guide roller 222 so as to be balanced in a state of being biased in the clockwise direction by the spring 224, the wire 4 is passed from the guide roller 222 to the lower side. Has been pulled out. The left rotational force by the dancer roller 10 that applies tension to the wire 4 and the right rotational force by the biasing force of the spring 224 that applies the same tension as the dancer roller 10 are balanced in a seesaw shape.

  In this case, when the tension of the wire 4 gradually or instantaneously increases and the wire 4 is pulled, the tension fluctuation is absorbed by rotating in the counterclockwise direction against the urging force of the spring 224 in the clockwise direction. Is done. Conversely, even if the tension of the wire 4 gradually or instantaneously decreases and the wire 4 is loosened, the balance with the biasing force of the spring 224 in the clockwise rotation direction is lost, and the biasing force of the spring 224 guides it in the clockwise rotation direction. As the rollers 221 and 222 rotate around the rotation shaft 223, the loosened portion of the wire 4 can be absorbed.

  The operation of the above configuration will be described below.

  FIG. 9A is a diagram schematically illustrating the tension monitoring result on the wire supply side with respect to the time axis (min), and FIG. 9B is a diagram schematically illustrating the wire traveling speed with respect to the time axis (min). FIG. 9C is a diagram schematically illustrating the tension monitoring result of the workpiece 7 cutting region with respect to the time axis (min).

  As described above, wire tension fluctuations are mainly caused by (1) wire acceleration / deceleration and (4) tension fluctuation ± 2.5N due to pulley inertia, (2) tension fluctuation ± 1N due to traverser folding, (3) bobbin The tension fluctuation is ± 2.5 N due to the winding direction of the wire, and (5) The tension fluctuation is ± 0.5 N due to the wire vibration, and a total tension fluctuation of ± 6.5 N is generated.

  As shown in FIG. 9A, the wire tension fluctuates in a ± 1N split mountain shape and a valley shape, for example, centering on a tension of 13.5N at the wire turn-back cycle by the traversers 22 and 23. In addition, a trigger-like tension fluctuation of ± 2.5 N is generated by the acceleration / deceleration accompanying the reciprocating travel of the wire. Further, a tension fluctuation of ± 2.5 N occurs due to a tension fluctuation depending on the winding direction of the supply bobbin 5 and the recovery bobbin 6.

  As shown in FIG. 9B, the workpiece 7 is cut into a number of wafers by reciprocating wire, but the wire 4 is accelerated or decelerated from a predetermined constant speed when the direction of the reciprocating wire is switched. The forward traveling and the backward traveling of the wire 4 have a time ratio of about 1000 to 990.

  As shown in FIG. 9A, the wire tension increases or decreases in a trigger-like manner at a position around the wire speed 0 at the time of wire acceleration / deceleration accompanying reciprocal switching of wire travel. Therefore, the influence of fluctuations in wire tension is large. The supply bobbins of the traversers 22 and 23 when the traversers 22 and 23 follow the supply bobbins 5 and the recovery bobbins 6 and the fixed abrasive wire 4 is fed out and wound up. 5 and when the tension fluctuation due to the winding direction to the recovery bobbin 6 is maximum, the maximum value of the wire tension fluctuation due to the wire folding operation by the traversers 22 and 23 overlaps, and the wire tension fluctuation due to the wire acceleration / deceleration during the reciprocating movement of the wire Wire tension fluctuations are maximized when they occur simultaneously. This is the maximum tension position T max indicated by the arrow in the left lateral direction in FIG. This maximum tension must not exceed the breaking tension 20N of the wire 4.

  The tension fluctuation absorbing means is configured such that the wire 4 guides from the right side of the guide roller 221 so that the two guide rollers 221 and 222 are balanced in a seesaw shape with the rotation shaft 223 therebetween being urged in the left rotation direction. After being passed in an S shape on the left side of the roller 222, the wire 4 is drawn out on the right side through the guide roller 222.

  In this case, when the tension of the wire 4 gradually or instantaneously increases and the wire 4 is pulled to the right, the counterclockwise direction of the tension applying means (rotating biasing means) counteracts the counterclockwise biasing force. The tension fluctuation is absorbed by rotating in the direction. Conversely, even if the tension of the wire 4 gradually or instantaneously decreases and the wire 4 loosens and moves to the left, the seesaw balance with the counterclockwise biasing force of the tension applying means (rotating biasing means). When the guide rollers 221 and 222 rotate around the rotation shaft 223 in the counterclockwise direction by the urging force of the tension applying means (rotation urging means) and the wire 4 is loosened, the loosened portion of the wire 4 can be absorbed.

  For this reason, (1) wire acceleration / deceleration and (4) tension fluctuation due to pulley inertia, which are the tension fluctuation factors, can be absorbed by ± 1N, and (2) tension fluctuation due to traverser folding can be absorbed ± 0N, (3) Tension fluctuation due to winding direction on bobbin can be suppressed to ± 1N, (5) Tension fluctuation due to wire vibration remains unchanged to ± 0.5N, and can be reduced to ± 2.5N. Thus, it becomes possible to perform processing by increasing the tension of the cutting region of the workpiece 7 to 17.5 N, and the cutting time can be shortened.

  In the wire saw device 1A of the second embodiment described above, the traversers 22A and 23A including the first wire tension fluctuation absorbing means, the tension fluctuation absorbing means 225 (first wire tension fluctuation absorbing means), and the traverser including the second wire tension fluctuation absorbing means. 22C, 23C, and further, the tension fluctuation absorbing means 226 (second wire tension fluctuation absorbing means) has been described. In the wire saw device of the second embodiment, the tension fluctuation due to the wire folding movement of the first traverser with respect to the supply bobbin 5 and First wire tension fluctuation absorbing means for absorbing the tension fluctuation due to the return movement of the second traverser with respect to the recovery bobbin 6, and second wire tension fluctuation absorbing means for absorbing the tension fluctuation during acceleration / deceleration accompanying the reciprocating switching of the wire reciprocating travel. And at least one of them may be provided.

  As described above, according to the second embodiment, the wire 4 of the supply bobbin 5 passes the traverser 22A and the dancer roller 10 and is wound around the grooved rollers 2 and 3 a plurality of times, and then passes through the dancer roller 13 and the traverser 23A to the recovery bobbin 6. It is wound up. The traversers 22A and 23A regularly wind or wind the wire 4 around the supply bobbin 5 and the recovery bobbin 6 while moving the traverser reciprocating range B in FIG. 4 so as to follow the winding position of the wire 4 around the supply bobbin 5 and the recovery bobbin 6. The traverser reciprocating range B is reciprocated by returning. When a relative displacement between the wire folding position and the traverser folding position of the supply bobbin 5 and the recovery bobbin 6 occurs, a tension fluctuation corresponding to the folding timing deviation occurs. However, like a seesaw having a rotation center 223 as shown in FIG. By providing such a tension fluctuation absorbing means, the tension fluctuation is absorbed and canceled between the supply bobbin 5 and the traverser 22A and between the recovery bobbin 6 and the traverser 23A, and the dancer rollers 10 and 13 are not affected by the tension fluctuation. Wire tension caused by wire wrapping when the wire 4 is moved in the bobbin width direction with respect to the supply bobbin 5 and the recovery bobbin 6 by absorbing the tension variation affecting the tension variation due to the acceleration by the tension variation absorbing means. Variations can be prevented and wire breakage can be prevented. Therefore, it is possible to quickly realize the cutting of the workpiece W with a higher tension than the conventional apparatus and without wire breakage.

  That is, by providing wire tension fluctuation absorbing means, at least one of wire tension fluctuation due to wire acceleration / deceleration accompanying wire reciprocating switching of wire traveling and wire tension fluctuation due to wire folding operation is absorbed. Can be prevented. Since the wire tension can be set higher as much as the fluctuation of the wire tension is suppressed or prevented, the workpiece can be efficiently cut without a wire break even with a higher tension than in the conventional apparatus.

  In the second embodiment, the two guide rollers 221 and 222 are arranged so as to be balanced in a seesaw shape with the rotation shaft 223 therebetween being urged in the left rotation direction, but the guide rollers 221 and 222 are independent. The spring 224 may be arranged so as to follow the displacement in the opposite direction.

  Although not specifically described in the first and second embodiments, the first and second embodiments may be combined. That is, the wire saw device according to the second embodiment is a wire saw apparatus that can process the tension fluctuation by further increasing the tension in the workpiece cutting region by providing a mechanism that does not exert the tension variation on the workpiece cutting region. A case where a mechanism for suppressing or preventing the tension fluctuation by the tension fluctuation absorbing means is provided will be described.

FIG. 10A is a diagram schematically illustrating the tension monitoring result on the wire supply side with respect to the time axis (min), and FIG. 10B is a diagram schematically illustrating the wire traveling speed with respect to the time axis (min). FIG. 10C is a diagram schematically illustrating the tension monitoring result of the workpiece 7 cutting region with respect to the time axis (min).
As shown in FIGS. 10 (a) to 10 (c), (1) wire acceleration / deceleration and (4) pulley inertia, which are tension fluctuations that could not be absorbed by the buffer bobbins 14, 18 of the first embodiment. By providing a tension fluctuation absorbing means, the tension fluctuation ± 2.5N can be reduced to ± 1N, and the work can be cut by raising the tension in the work cutting area 31 to 19N. The cutting time can be shortened, and the effect of the present invention that can efficiently cut the workpiece without wire breakage with higher tension compared to the conventional apparatus is enhanced.

  That is, one end of the wire 4 wound between the grooved rollers 2 and 3 arranged at a predetermined interval is wound around the supply bobbin 5 via the first dancer roller 10, and the other end is routed via the second dancer roller 13. In the wire saw device 1 that is wound around the recovery bobbin 6 and reciprocates the wire 4 to cut the workpiece 7 by a plurality of rows of the wires 4 between the grooved rollers 2 and 3, the grooved rollers 2 and 3 and the first dancer roller The first buffer bobbins 14 and 18 are respectively disposed between the first and second dancer rollers 13, and the third dancer roller 17 is disposed between the grooved rollers 2 and 3 and the buffer bobbin 14. A fourth dancer roller 21 is disposed between the double grooved rollers 2 and 3 and the buffer bobbin 18. In this case, the first wire tension fluctuation absorbing means for absorbing the tension fluctuation caused by the wire folding movement of the first traverser 22 relative to the supply bobbin 5 and the tension fluctuation caused by the wire folding movement of the second traverser 23 relative to the recovery bobbin 6; At least one of the second wire tension fluctuation absorbing means for absorbing the tension fluctuation at the time of acceleration / deceleration accompanying the reciprocating switching of traveling may be provided. In particular, the second wire tension fluctuation absorbing means is provided between the grooved rolls 2 and 3 and the buffer bobbins 14 and 18 and between the buffer bobbin 14 and the first traverser 22 and between the buffer bobbin 18 and the second traverser 23. It is arranged between each of at least one of them.

  As described above, each of the first wire tension fluctuation absorbing means and the second wire tension fluctuation absorbing means is provided such that the guide rollers 221 and 222 are rotatably provided at both ends of the plate body, respectively. A rotation shaft 223 is provided between the guide rollers 221 and 222. The guide rollers 221 and 222 are rotatably supported around the rotation shaft 223, and the wire 4 is urged to the guide rollers 221 and 222 in one rotation direction. The tension applying means is provided so as to urge in the other rotation direction, and the urging force in one rotation direction and the urging force in the other rotation direction are set in an equilibrium state.

  In other words, one end of the cutting wire 4 wound between the plurality of grooved rollers 2 and 3 arranged at a predetermined interval is wound around the supply bobbin 5 via the first dancer roller 10, and the other end. Is wound around the recovery bobbin 6 via the second dancer roller 13, and a first traverser 22A that moves following the wire winding position of the supply bobbin 5 is provided between the supply bobbin 5 and the first dancer roller 10. Between the dancer roller 13 and the recovery bobbin 6, a second traverser 23A that moves following the wire winding position of the recovery bobbin 6 is provided, and the wire 4 is reciprocated to move the wire between the plurality of grooved rollers 2 and 3. In the wire saw apparatus 1A that cuts the workpieces 7 in a plurality of four rows, the tension fluctuation caused by the wire folding movement of the first traverser 22A relative to the supply bobbin 5 and the recovery First wire tension fluctuation absorbing means for absorbing the tension fluctuation due to the wire folding movement of the second traverser 23A relative to the bin 6, and second wire tension fluctuation absorbing means for absorbing the tension fluctuation during acceleration / deceleration accompanying the reciprocating switching of the wire reciprocating travel. Or at least one of them. In this case, the first buffer bobbins 14 and 18 are disposed between the grooved rollers 2 and 3 and the first dancer roller 10 and the second dancer roller 13, respectively. A third dancer roller 17 may be disposed therebetween, and a fourth dancer roller 21 may be disposed between the double grooved rollers 2 and 3 and the buffer bobbin 18. In particular, the second wire tension fluctuation absorbing means is provided between the grooved roll 2.3 and the first dancer roller 10 and the second dancer roller 13, and between the first dancer roller 10, the first traverser 22A, the second dancer roller 12 and the second dancer roller 12. What is necessary is just to be arrange | positioned between each of at least any of each between the traversers 23A.

  The wire saw device 1 provided with the buffer bobbins 14 and 18 will be described in the first embodiment, and the wire saw device 1A provided with the tension fluctuation absorbing means provided in the traverser, the tension fluctuation absorbing means 225, 226 and the like will be described in the embodiment. The wire saw device 1 provided with the buffer bobbins 14 and 18 is the main configuration, whereas the tension fluctuation absorbing means provided in the traverser, Needless to say, the tension fluctuation absorbing means 225 and 226 may be provided. Conversely, the wire saw device 1A provided with the tension fluctuation absorbing means provided in the traverser, the tension fluctuation absorbing means 225, 226, etc. is the main configuration, and the buffer bobbins 14, 18 are the same as those of the first embodiment. It goes without saying that the same position may be provided.

  The present invention is a wire saw device capable of efficiently cutting a workpiece without wire breakage even at a higher tension as compared with the conventional device, and is (1) wire acceleration / deceleration, (4) pulley inertia, which is a factor of tension fluctuation. (1) Wire acceleration / deceleration, (5) Tension due to wire vibration, (2) Tension variation due to traverser folding, (3) Tension variation due to bobbin winding direction, (5) Tension variation due to wire vibration A wire saw device capable of cutting a workpiece by further increasing the tension of the workpiece cutting region 31 by providing a mechanism (buffer bobbins 14 and 18) that does not exert a tension variation other than the variation on the workpiece cutting region. This is a workpiece cutting method using this. That is, an object of the present invention is to provide a wafer manufacturing method in which a wafer is manufactured by cutting a plurality of wafers with a wire row of a wire saw apparatus using this solution.

  The present invention is also a wire saw device capable of efficiently cutting a workpiece without wire breakage even at a higher tension than that of the conventional device, and (1) wire acceleration / deceleration, (4) pulley, which is a factor of tension fluctuation. Tension fluctuation due to factors (1) to (4) among tension fluctuation due to inertia, (2) tension fluctuation due to traverser folding, (3) tension fluctuation due to bobbin winding direction, (5) tension fluctuation due to wire vibration This is a wire saw device 1A that can further increase the tension at the time of cutting a workpiece by suppressing or preventing the tension fluctuation absorbing means, and a workpiece cutting method using the wire saw device 1A. That is, an object of the present invention is to provide a wafer manufacturing method in which a wafer is manufactured by cutting a plurality of wafers with a wire row of a wire saw apparatus 1A using this solution.

  As mentioned above, although this invention was illustrated using preferable Embodiment 1, 2 of this invention, this invention should not be limited and limited to this Embodiment 1,2. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge, from the description of specific preferred embodiments 1 and 2 of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  The present invention relates to a wire saw device for cutting a workpiece with a cutting wire by running a cutting wire passed through the outer periphery of a plurality of grooved rollers arranged at a predetermined interval, and a workpiece cutting method using the same. In the field of a wafer manufacturing method for manufacturing a wafer by cutting a workpiece into a plurality of wafers with a wire row of a wire saw device, a wire by bobbin folding having a large tension variation with respect to the wire tension of a cutting region for cutting the workpiece Since the buffer bobbin is not affected by fluctuations in tension, the wire tension in the cutting area can be set higher, and the wire tension can be set lower in areas where there is fluctuation in wire tension due to bobbin folding. The workpiece can be cut efficiently with higher wire tension than In the region where the wire tension variation is present by can be suppressed or prevented wire breakage weakening the wire tension.

DESCRIPTION OF SYMBOLS 1, 1A Wire saw apparatus 2, 3 Grooved roller 4 Wire for cutting 5 Supply bobbin on new line supply side 6 Collection bobbin on old line collection side 7 Work 8, 9 Guide roller 10 of inertial drive 10 First dancer rollers 11, 12 Inertia Driving guide roller 13 Second dancer roller 14 Buffer bobbin (first buffer bobbin means)
15, 16 Inertial drive guide roller 17 Third dancer roller 18 Buffer bobbin (second buffer bobbin means)
19, 20 Inertial drive guide roller 21 Fourth dancer roller 22, 23 Traverser 24, 25 Processing fluid supply part 26 Fixing part 27 Work feed mechanism 31 Work cutting area 32 Supply area 33 Collection area 22A, 23A, 22B, 23B, 22C, 23C traverser 221, 222 guide roller 223 rotating shaft 224 spring (tension applying means)
225 Tension fluctuation absorbing means (first wire tension fluctuation absorbing means)
226 Tension fluctuation absorbing means (second wire tension fluctuation absorbing means)

Claims (27)

One end of a cutting wire wound between a plurality of grooved rollers arranged at a predetermined interval is wound around a supply bobbin via a first dancer roller, and the other end is wound around a recovery bobbin via a second dancer roller. In a wire saw device that is wound and reciprocates the wire to cut a workpiece with a plurality of rows of wires between the plurality of grooved rollers,
A first buffer bobbin means and a second buffer bobbin means are disposed between the plurality of grooved rollers and the first dancer roller and the second dancer roller, respectively. The plurality of grooved rollers and the first buffer A wire saw device in which a third dancer roller is disposed between bobbin means and a fourth dancer roller is disposed between the plurality of grooved rollers and the second buffer bobbin means. The wire saw device according to claim 1,
The wire saw device in which each tension value managed by the first dancer roller and the second dancer roller is set to a value lower than each tension value managed by the third dancer roller and the fourth dancer roller. In the wire saw device according to claim 1 or 2,
The first buffer bobbin means and the second buffer bobbin means respectively have a tension fluctuation caused by a wire folding operation of the traverser with respect to the supply bobbin and a tension fluctuation caused by the wire folding action of the traverser with respect to the recovery bobbin. A wire saw device having a wire winding length that does not affect each tension value managed by the fourth dancer roller. The wire saw device according to claim 3,
Each tension value managed by the third dancer roller and the fourth dancer roller is higher than each tension value managed by the first dancer roller and the second dancer roller within a range of tension fluctuation values due to the wire folding operation of the traverser. Wire saw device set. The wire saw device according to claim 1,
A wire saw device in which each tension value managed by the third dancer roller and the fourth dancer roller is set and controlled to be lower than each tension value when the wire speed is constant during wire acceleration / deceleration accompanying reciprocal switching of wire travel. The wire saw device according to claim 1,
A wire saw device in which the workpiece feed amount is temporarily set to 0 during wire acceleration / deceleration associated with reciprocating switching of wire travel. The wire saw device according to claim 1,
A wire saw device in which each of the first buffer bobbin means and the second buffer bobbin means comprises one or a plurality of grooved rollers. The wire saw device according to claim 1,
A first traverser that moves following the wire winding position of the supply bobbin is provided between the supply bobbin and the first dancer roller, and wire winding of the recovery bobbin is performed between the second dancer roller and the recovery bobbin. There is a second traverser that moves following the position,
First wire tension fluctuation absorbing means for absorbing fluctuations in tension caused by wire folding movement of the first traverser relative to the supply bobbin and tension fluctuations caused by wire folding movement of the second traverser relative to the recovery bobbin; A wire saw device provided with at least one of second wire tension fluctuation absorbing means for absorbing tension fluctuation during acceleration / deceleration accompanying the acceleration and deceleration. The wire saw device according to claim 8, wherein
A wire saw apparatus in which the first traverser and the second traverser are each provided with the first wire tension fluctuation absorbing means. The wire saw device according to claim 8, wherein
The wire saw device, wherein the first wire tension fluctuation absorbing means is disposed between the supply bobbin and the first traverser and between the recovery bobbin and the second traverser. The wire saw device according to claim 8, wherein
The second wire tension fluctuation absorbing means is provided between each of the grooved roll and the first buffer bobbin means and the second buffer bobbin means, and between the first buffer bobbin means, the first traverser, and the second buffer. A wire saw device disposed between at least one of the bobbin means and the second traverser. The wire saw device according to claim 8, wherein
In each of the first wire tension fluctuation absorbing means and the second wire tension fluctuation absorbing means, each guide roller is rotatably provided at both ends of the plate, and a rotation shaft is provided between the guide rollers. Each guide roller is rotatably supported around a rotation axis, and the wire is passed through each guide roller so as to bias it in one rotation direction and tension so as to bias it in the other rotation direction. A wire saw device in which an applying means is provided and the biasing force in the one rotation direction and the biasing force in the other rotation direction are set in an equilibrium state. The wire saw device according to claim 12, wherein
The tension applying means applies the same tension to each guide roller as the tension by the first dancer roller and the second dancer roller, and each guide roller is in an equilibrium state with the rotation axis as a rotation center. apparatus. One end of a cutting wire wound between a plurality of grooved rollers arranged at a predetermined interval is wound around a supply bobbin via a first dancer roller, and the other end is wound around a recovery bobbin via a second dancer roller. In a workpiece cutting method in which the wire is reciprocated to cut the workpiece with a plurality of rows of wires between the plurality of grooved rollers,
A first buffer bobbin means and a second buffer bobbin means are disposed between the plurality of grooved rollers and the first dancer roller and the second dancer roller, respectively. The plurality of grooved rollers and the first buffer A work cutting method in which a third dancer roller is disposed between bobbin means and a fourth dancer roller is disposed between the plurality of grooved rollers and the second buffer bobbin means. In the workpiece cutting method according to claim 14,
A workpiece cutting method in which each tension value managed by the first dancer roller and the second dancer roller is set to a value lower than each tension value managed by the third dancer roller and the fourth dancer roller. In the workpiece cutting method according to claim 14 or 15,
The first buffer bobbin means and the second buffer bobbin means respectively change the tension fluctuation caused by the wire folding operation of the traverser with respect to the supply bobbin and the tension fluctuation caused by the wire folding action of the traverser with respect to the recovery bobbin. A workpiece cutting method having a wire winding length that does not affect each tension value managed by the fourth dancer roller. The work cutting method according to claim 16, wherein
The tension values managed by the third dancer roller and the fourth dancer roller are higher than the tension values managed by the first dancer roller and the second dancer roller within a range of tension fluctuation values due to the wire folding operation of the traverser. The workpiece cutting method to be set. In the workpiece cutting method according to claim 14,
A workpiece cutting method in which each tension value managed by the third dancer roller and the fourth dancer roller is set and controlled to be lower than each tension value when the wire speed is constant during wire acceleration / deceleration accompanying reciprocal switching of wire travel. In the workpiece cutting method according to claim 14,
A workpiece cutting method in which the workpiece feed amount is temporarily set to 0 during wire acceleration / deceleration accompanying reciprocal switching of wire travel. In the workpiece cutting method according to claim 14,
The work cutting method, wherein each of the first buffer bobbin means and the second buffer bobbin means comprises one or a plurality of grooved rollers. In the workpiece cutting method according to claim 14,
A first traverser that moves the wire following the wire winding position of the supply bobbin is provided between the supply bobbin and the first dancer roller, and the recovery bobbin is disposed between the second dancer roller and the recovery bobbin. A second traverser that moves the wire following the wire winding position is provided,
First wire tension fluctuation absorbing means for absorbing fluctuations in tension caused by wire folding movement of the first traverser relative to the supply bobbin and tension fluctuations caused by wire folding movement of the second traverser relative to the recovery bobbin; A workpiece cutting method provided with at least one of second wire tension fluctuation absorbing means for absorbing tension fluctuation at the time of acceleration / deceleration accompanying the acceleration and deceleration. The work cutting method according to claim 21, wherein
A workpiece cutting method in which the first traverser and the second traverser are provided with the first wire tension fluctuation absorbing means, respectively. The work cutting method according to claim 21, wherein
The work cutting method in which the first wire tension fluctuation absorbing means is disposed between the supply bobbin and the first traverser and between the recovery bobbin and the second traverser. The work cutting method according to claim 21, wherein
The second wire tension fluctuation absorbing means is provided between each of the grooved roll and the first buffer bobbin means and the second buffer bobbin means, and between the first buffer bobbin means, the first traverser, and the second buffer. A work cutting method arranged between at least one of bobbin means and the second traverser. The work cutting method according to claim 21, wherein
In each of the first wire tension fluctuation absorbing means and the second wire tension fluctuation absorbing means, each guide roller is rotatably provided at both ends of a belt-like plate body, and a rotation shaft is provided between the guide rollers. The guide rollers are rotatably supported around the rotation shaft, and the wires are passed through the guide rollers so as to be biased in one rotation direction, and are biased in the other rotation direction. A workpiece cutting method in which a tension applying means is provided to set the urging force in the one rotation direction and the urging force in the other rotation direction to an equilibrium state. The work cutting method according to claim 25,
The tension applying means applies the same tension to the guide rollers as the tensions of the first dancer roller and the second dancer roller, and equilibrates the guide rollers with the rotation axis as a rotation center.   27. The work cutting method according to claim 14, wherein the work is a semiconductor ingot, and the semiconductor ingot is cut into a plurality of wafers by a wire row of a wire saw device. A method for manufacturing a wafer to be manufactured.