JP2012236256A - Wire saw device, and cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress local tension fluctuation of a wire generated during oscillation cutting.SOLUTION: This wire saw device 1 cuts a workpiece W by pressing the workpiece W on the wire 3 oscillating while traveling. In an oscillating wire guide support part 4, a pair of wire guides 2 rotating while being separated from each other are arranged. One wire 3 is wound around the pair of wire guides 2 to form wire groups 3a substantially parallel to each other between the wire guides 2. A wire travel path 14 for guiding the wire 3 is provided between winders 6 and 7 capable of unwinding and winding the wire 3 and the wire guides 2. A control device 8 includes winder speed control means 8a tuned with the oscillation of the wire guide support part 4 to control rotational speed of the winders 6 and 7.

Description

  The present invention relates to a wire saw device and a cutting method used for cutting out a thin plate-like substrate from, for example, a silicon ingot or the like.

  Generally, in this type of wire saw device, a cutting wire (also simply referred to as a wire) is spirally wound around a roll-shaped wire guide that is spaced apart. By doing so, a group of wires arranged in parallel is formed between the wire guides. By controlling the travel of the wires, each wire of the wire group travels in the same direction at the same speed. By pressing a silicon ingot or the like (also referred to as a workpiece) against the wire group, a plurality of substrates can be simultaneously cut out from the workpiece.

  However, as cutting progresses, the cutting load increases and it becomes difficult for chips to be discharged. Therefore, a method of cutting while rocking the wire (rocking cutting) has been proposed (Patent Document 1). When the wire is swung, the amount of contact between the workpiece and the wire is reduced as a whole, so that the cutting speed is increased and chips are easily discharged.

Japanese Unexamined Patent Publication No. 01-171753

  However, when swing cutting is performed, local tension fluctuations may occur in the wire. In that case, there is a risk of causing problems such as a decrease in cutting accuracy and wire breakage.

  FIG. 1 schematically shows a wire saw device that performs rocking cutting. In the drawing, the wire 101 is unwound from the supply winder 102 and is taken up by the take-up winder 103. An intermediate portion of the wire 101 is wound around a pair of wire guides including a supply side guide 104 and a winding side guide 105, and a wire group is formed between the wire guides 104 and 105. The workpiece W is pressed against the wire group, and the workpiece W is cut.

  A plurality of pulleys P for guiding the wire 101 are arranged between the supply side guide 104 and the supply winder 102 and between the winding side guide 105 and the winding winder 103. The tension of the wire 101 is kept constant by the tension pulley Pt. As shown to (a) and (b) of the figure, a pair of wire guides 104 and 105 rock-displace.

  For example, if the wire guides 104 and 105 are swung and displaced as shown in FIG. 5A, the traveling distance of the wire 101 from the supply winder 102 to the supply side guide 104 becomes relatively long. On the other hand, the travel distance of the wire 101 from the winding side guide 105 to the winding winder 103 is relatively short. As a result, the wire 101 is loosened in the vicinity of the winding side guide 105, and the wire 101 is pulled in the vicinity of the supply side guide 104.

  Further, if the rocking displacement is made as shown in FIG. 5B, the traveling distance of the wire 101 from the supply winder 102 to the supply side guide 104 becomes relatively short, and the take-up winder 103 extends from the take-up side guide 105. The traveling distance of the wire 101 leading to is relatively long. As a result, the wire 101 is pulled in the vicinity of the winding side guide 105, and the wire 101 is loosened in the vicinity of the supply side guide 104. By repeating the states (a) and (b) in the figure, a local tension state and a loose state repeatedly occur in the wire 101.

  Therefore, an object of the present invention is to provide a wire saw device and a cutting method that can effectively suppress the occurrence of fluctuations in wire tension.

  The wire saw device of the present invention is a wire saw device that presses a workpiece against a cutting wire that swings while traveling and cuts the workpiece. The wire saw device is disposed on a wire guide support portion that swings around a swing shaft in a range of a predetermined angle from a reference position substantially perpendicular to a direction in which the workpiece is pressed, and the wire guide support portion. A pair of wire guides, each of which is separated from each other and rotates about a rotation axis parallel to the swing axis, and a single cutting wire is spirally wound around the pair of wire guides, A substantially parallel wire group formed between the wire guides, a winder capable of unwinding and winding the cutting wire, and provided between the wire guide and the winder to guide the cutting wire. A wire travel path, a workpiece holding unit that supports the workpiece, displaces and presses the workpiece against the wire group, and a control device.

  The control device includes a winder speed control means for controlling the rotation speed of the winder in synchronization with the swing of the wire guide support portion.

  According to the wire saw device having such a configuration, the winder speed control means cooperates with the winder or the like, so that the rotation speed of the winder can be controlled in synchronization with the swing of the wire guide support portion.

  In other words, the winder rotation speed can be increased / decreased in accordance with the change in the length of the wire travel path accompanying the swinging of the wire guide support, so that the wire unwinding amount and winding amount can be increased by the changed length. Can be increased or decreased. Therefore, even if the length of the wire travel path changes due to the swing, the tension of the wire can be made constant, and the occurrence of local tension fluctuations of the wire can be effectively suppressed.

  Specifically, when the winder is unwinding the cutting wire, the winder speed control means is configured to cause the wire travel when the wire guide support portion swings in a direction in which the wire travel path becomes longer. What is necessary is just to control so that the rotational speed of the said winder becomes large rather than the time of the said wire guide support part rock | fluctuating in the direction where a path | route becomes short.

  Then, when the wire travel path becomes longer, the winder has a higher rotational speed than when the wire travel path becomes shorter, so when the wire is pulled, the amount of unwinding of the wire becomes relatively large, When the wire is loosened, the amount of unwinding of the wire is relatively reduced. Therefore, the difference in length between the wire travel route and the wire traveling on the wire travel route is almost eliminated, so that the occurrence of local tension fluctuation of the wire can be effectively suppressed.

  For example, the winder speed control means includes control parameters set in advance, and the rotation speed of the winder can be controlled based on the control parameters. Then, it is not necessary to use a complicated device, and it can be realized relatively easily by utilizing an existing device.

  In addition, when a tension pulley that keeps the tension of the cutting wire constant is provided in the wire travel path, the winder speed control unit is configured to perform the above-described measurement based on the measured displacement amount of the tension pulley. Correction means for controlling the rotation speed of the winder can be provided.

  By doing so, even if the tension changes during processing, the rotational speed of the winder can be corrected accordingly, so that the local tension fluctuation of the wire can be stably suppressed.

  The cutting method preferably includes a winder speed control step of automatically controlling the traveling speed of the cutting wire in synchronization with the swinging of the cutting wire. Then, the traveling speed of the wire is automatically controlled in accordance with the swinging of the wire, so that complicated processing is not required, and high-precision cutting can be easily performed.

  According to the wire saw device and the like of the present invention, it is possible to effectively suppress fluctuations in tension that may occur when performing rocking cutting, so that highly accurate cutting can be stably performed.

(A), (b) is the figure which showed simply the different state of the conventional wire saw apparatus which is performing rocking | fluctuation cutting. It is the schematic which shows the whole structure of the principal part of the wire saw apparatus which concerns on embodiment. It is the schematic of the principal part of a wire saw apparatus. It is a figure for demonstrating the change of a wire travel path | route. It is a figure for demonstrating the change of a wire travel path | route. It is the table | surface which put together about the rotational speed control of each winder according to the combination of the running direction of a wire, and the rocking directions of a wire guide support part. It is a time chart of the rotational speed of each winder with respect to a rocking angle. (A) is the change over time of the swing angle, (b) is the change over time in the rotational speed of each winder during forward travel corresponding to (a), and (c) is each winder during reverse travel corresponding to (a). Is the change with time of the rotational speed of It is a figure for demonstrating the displacement of a tension pulley. It is a flowchart which shows the flow of control by a correction program. (A) is a flowchart of the supply winder during forward traveling, and (b) is a flowchart of the winding winder during forward traveling. It is the table | surface which put together about correction | amendment control of the rotational speed of each winder according to the combination of the traveling direction of a wire, and the displacement direction of a tension pulley.

(Wire saw device)
In FIG. 2, the wire saw apparatus 1 of this embodiment is shown. The wire saw device 1 is used, for example, for cutting a column-shaped workpiece (referred to as a workpiece W) such as a silicon ingot used for manufacturing a semiconductor device or a solar cell into a plurality of thin plate-like substrates. . The wire saw device 1 includes a wire guide 2, a cutting wire 3, a wire guide support 4, a supply winder 6, a winding winder 7, a control device 8, a side wall plate 10, a tension holding mechanism 11, a wire travel path 14, and a workpiece holding. The unit 50 and the like are provided.

  The side wall plate 10 is a part of a wall body that defines a processing region of the wire saw device 1, and has a through-hole 12 that opens in a circular shape on a side surface facing the processing region. A rocking disk 91 is disposed inside the through hole 12. The oscillating disk 91 is oscillated and displaced about the oscillating axis A1 passing through the center of the through hole 12.

  The wire guide support portion 4 is fixed to one side surface (processing region side) of the swing disk 91. The wire guide support portion 4 is also oscillated and displaced about the oscillation axis A1. The wire guide support portion 4 is composed of a pair of support walls 4a, 4a facing away from each other in the direction of the swing axis A1, a connecting wall 4b connected to one end of the support walls 4a, and the like. A pair of wire guides 2, 2 are arranged on the opposite side (work W side) of the connecting wall 4 b in the wire guide support portion 4.

  The wire guide 2 has a cylindrical shape. The end portions of the wire guides 2 are supported by both supporting wall portions 4a, and the wire guides 2 are separated from each other and are arranged in parallel. The wire guide 2 rotates around a rotation axis A2 parallel to the swing axis A1 in synchronization with each other. The swing axis A1 is located at the midpoint of the line segment connecting these two rotation axes A2 (see FIG. 3).

  A wire guide drive motor 20 and a swing drive motor 92 are attached to the other side surface (back side) of the swing disk 91. The swing disk 91 swings by driving the swing drive motor 92, and the wire guide 2 rotates by driving the wire guide drive motor 20. The swing drive motor 92 and the wire guide drive motor 20 are driven and controlled by the control device 8.

  In the present embodiment, a fixed abrasive wire in which fine abrasive grains such as diamond are fixed to the surface of the wire 3 is used for the cutting wire 3 (also referred to as the wire 3). For example, one wire 3 having a length of 100 m or more is used for one wire saw device 1. The wire 3 is spirally wound around the pair of wire guides 2, 2 so that a plurality of substantially parallel rows of wires 3 (also referred to as a wire group 3 a) is formed between the pair of wire guides 2, 2. Yes.

  Specifically, as shown in FIG. 3, the intermediate portion of the wire 3 is repeatedly wound around the entire pair of wire guides 2 and stretched between the wire guides 2. The wire 3 passes through the workpiece W side of one wire guide 2 (supply side wire guide 2) to the other wire guide 2 (winding side wire guide 2), and is wound around the winding side wire guide 2. It has been. The wire 3 wound around the winding-side wire guide 2 is stretched to the supply-side wire guide 2 through the connecting wall 4 b side, and is wound around the supply-side wire guide 2. This state is repeatedly performed at a predetermined pitch in the direction of the rotation axis A2, and finally the wire 3 is drawn from the work W side of the winding-side wire guide 2.

  The wire 3 drawn outward from the supply wire guide 2 is guided to a wire travel path 14 (also referred to as a supply-side wire travel path 14a) and extends to the supply winder 6. A plurality of pulleys P are arranged on the supply side wire travel path 14a, and the wire 3 is wound around these pulleys P and extends to the supply winder 6 while changing its direction.

  The supply winder 6 includes a supply-side bobbin 61, a supply-side assist motor 62, and the like. First, a supply-side bobbin 61 around which a new wire 3 is wound is attached to the supply winder 6. The supply-side assist motor 62 rotates the supply-side bobbin 61 in cooperation with the control device 8 to unwind or wind the wire 3.

  The wire 3 drawn outward from the winding-side wire guide 2 is guided to a wire traveling path 14 (also referred to as a winding-side wire traveling path 14b) and extends to the winding winder 7. A plurality of pulleys P are disposed on the winding-side wire travel path 14b, and the wire 3 is wound around these pulleys P and extends to the winding winder 7 while changing its direction.

  The winding winder 7 includes a winding side bobbin 71, a winding side assist motor 72, and the like. First, the winding winder 7 is mounted with an empty winding-side bobbin 71 in which the wire 3 is not wound. The winding side assist motor 72 rotates the winding side bobbin 71 in cooperation with the control device 8 to wind or unwind the wire 3.

  In the present embodiment, the pulley P (first pulley P1) on which the wire 3 drawn out from the wire guide 2 is first wound is secured to the workpiece as viewed from the axial direction so that the wire group 3a is not separated from the wire guide 2. They are arranged away from both wire guides 2 in the direction opposite to the W side.

  In order to hold and control the tension of the wire 3 to be constant, a tension holding mechanism 11 is provided in each wire travel path 14. The tension holding mechanism 11 includes a tension arm 11a, a tension motor 11b, a tension pulley P2, and the like.

  A tension pulley P2 is rotatably supported at the distal end of the tension arm 11a, and the shaft of the tension motor 11b is fixed to the proximal end of the tension arm 11a. The tension pulley P2 is rotationally displaced about the shaft. The length of the wire travel path 14 is changed by the displacement of the tension pulley P2.

  A tension motor 11b made of a servo motor or the like applies a constant torque to the tension arm 11a. Thereby, the tension of the wire 3 is kept constant. The tension motor 11b is provided with an encoder (not shown). By this encoder, the displacement amount of the rotation angle of the tension arm 11a, that is, the displacement amount of the position of the tension pulley P2 is actually measured. The tension motor 11b of this embodiment is connected to the control device 8, and the control device 8 receives the displacement amount of the tension pulley P2 from the tension motor 11b.

  In the wire saw device 1 of the present embodiment, the wire 3 is unwound in each of the supply winder 6 and the winder 7 by driving the wire guide drive motor 20 and both assist motors 62 and 72 by alternately changing the rotation direction. And winding of the wire 3 are repeated alternately.

  Specifically, the wire 3 having a predetermined length is unwound from the supply side bobbin 61, the wire 3 travels from the supply winder 6 side toward the take-up winder 7 side, and is taken up by the take-up side bobbin 71 ( Travel forward). Subsequently, the wire 3 is unwound from the take-up bobbin 71 by a length shorter than a predetermined length, and the wire 3 travels from the take-up winder 7 side to the supply winder 6 side. It is taken up again (reverse running). By repeating this forward traveling and reverse traveling processing alternately, the new wire portion of the wire 3 is sequentially fed out from the supply-side bobbin 61, and the wire 3 is sequentially transferred from the supply-side bobbin 61 to the winding-side bobbin 71. It will be rolled up.

  The workpiece holding unit 50 is configured by a workpiece holding member 51, a workpiece lifting / lowering motor 52, and the like, and is disposed apart from the wire guide support unit 4 on the workpiece W side. Specifically, as shown in FIG. 3, as viewed from the axial direction, the extension line L passes through the swing axis A1 and is substantially perpendicular to the line connecting the two rotation axes A2 when the swing angle is 0. The work holding member 51 is located on the top. One end (also referred to as a table 51a) of the work holding member 51 faces the wire group 3a, and the work W is detachably supported on the table 51a.

  A workpiece lifting / lowering motor 52 is disposed on the other end side of the workpiece holding member 51. The workpiece lifting / lowering motor 52 cooperates with the control device 8 to displace the workpiece holding member 51 along the extension line L by a ball screw mechanism (not shown).

  The control device 8 includes hardware such as a CPU and a memory, and software such as a control program installed in the memory. The control device 8 is connected to a wire guide drive motor 20, a workpiece elevating motor 52, a supply side assist motor 62, a winding side assist motor 72, a swing drive motor 92, and the like. doing.

  Specifically, the control device 8 controls the drive of the work lifting / lowering motor 52. Thereby, the workpiece holding member 51 and the workpiece W are displaced toward the wire group 3a, and the workpiece W is always pressed against the wire 3 until it is cut.

  The control device 8 also controls the drive of the swing drive motor 92. As a result, the oscillating disk 91 oscillates, and the wire guide support 4, the wire guide 2, and the wire group 3 a oscillate together with the oscillating disk 91. Specifically, as shown in FIG. 3, the wire guide support portion 4 is within a predetermined angle (θ) clockwise and counterclockwise from the reference position of the swing angle 0 perpendicular to the extension line L. Etc. are oscillated and displaced about the oscillating axis A1.

  Further, the control device 8 controls driving of the wire guide drive motor 20, the supply side assist motor 62, and the winding side assist motor 72. As a result, the unwinding and winding processes of the wire 3 are repeated alternately, and the wire 3 is gradually wound from the supply side bobbin 61 to the winding side bobbin 71.

  The control device 8 controls the drive of the wire guide drive motor 20 and the like and the wire guide support portion 4 and the like at the same time. As a result, the wire group 3a is oscillated and displaced in the traveling state, and the length of the wire traveling path 14 changes repeatedly.

  For example, as shown in FIG. 4, when the wire guide 2 swings clockwise from the reference position (virtual line) where the swing angle is 0, the drawing position of the wire 3 moves away from the first pulley P1. As a result, the wire travel path 14 becomes longer than the wire travel path 14 at the reference position by the distance (L1) that has moved away. Further, as shown in FIG. 5, when the wire 3 swings counterclockwise from the reference position (virtual line), the drawing position of the wire 3 approaches the first pulley P1. As a result, the wire travel path 14 becomes shorter than the wire travel path 14 at the reference position by the approached distance (L2).

  As a result, since the wire 3 is repeatedly pulled or loosened, there is a possibility of causing problems such as a decrease in cutting accuracy and a disconnection of the wire 3. Further, when the influence of the tension fluctuation reaches the tension pulley P2, the length of the wire travel path 14 also fluctuates, which may increase the local tension fluctuation and may become more unstable.

  Therefore, a winder speed control program 8a (winder speed control means) for controlling the rotational speed of the supply winder 6 and the winding winder 7 is provided in the control device 8 in order to suppress the occurrence of fluctuations in the tension of the wire 3 caused by swinging. It has been incorporated.

  The winder speed control program 8a cooperates with the assist motors 62 and 72 to execute processing for controlling the rotational speed of the winders 6 and 7 in synchronization with the swing of the wire guide support portion 4 and the like. This point will be specifically described with reference to an example in which the vehicle is traveling forward.

  In the supply side wire travel path 14a, the wire 3 is pulled when the wire guide support portion 4 or the like swings clockwise (in the direction in which the supply side wire travel path 14a becomes longer). Therefore, the winder speed control program 8a increases the rotation speed of the supply winder 6 in order to wind many wires 3 in accordance with the change in the length. When the wire guide support 4 or the like swings counterclockwise (the direction in which the supply-side wire travel path 14a is shortened), the wire 3 is loosened. Therefore, the winder speed control program 8a decreases the rotational speed of the supply winder 6 in order to unwind the wire 3 in accordance with the change in the length.

  In the winding-side wire travel path 14b, the wire 3 is loosened when the wire guide support portion 4 or the like swings clockwise (in the direction in which the winding-side wire travel path 14b is shortened). Accordingly, the winder speed control program 8a increases the rotational speed of the winder 7 in order to wind up more wires 3 in accordance with the change in length. When the wire guide support portion 4 or the like swings counterclockwise (the direction in which the winding-side wire travel path 14b becomes longer), the wire 3 is pulled. Therefore, the winder speed control program 8a reduces the rotational speed of the winder 7 in order to wind up the wire 3 less according to the change in the length.

  In the case of reverse traveling, the traveling direction of the wire 3 is reversed, so that the control of the rotational speed of the winders 6 and 7 is also changed accordingly. FIG. 6 shows a table in which the rotational speeds of the winders 6 and 7 are controlled according to combinations of the traveling direction of the wire 3 and the swinging direction of the wire guide support 4 and the like.

  In order to control the rotation speed of each of the winders 6 and 7, control parameters are preset in the winder speed control program 8a. The control parameter is calculated from the mechanical conditions of the wire saw device 1. For example, a control parameter for increasing or decreasing the rotational speed of the winders 6 and 7 is set so that the tension pulley P2 is stabilized at a predetermined reference position even when the wire guide support 4 or the like swings, that is, no tension fluctuation occurs. The rotation speed of each winder 6, 7 is controlled using this control parameter.

  Further, the winder speed control program 8a of the present embodiment is also provided with a correction program 8b (correction means). The correction program 8b executes a process for correcting the rotational speeds of the winders 6 and 7 based on the actually measured value of the displacement amount of the tension pulley P2.

  When the tension of the wire 3 is not constant and is variably controlled, or when the tension of the wire 3 changes with time, the control using the control parameter cannot cope. Therefore, by correcting the rotational speed of each winder 6, 7 based on the actually measured value of the displacement amount of the tension pulley P2 by the correction program 8b, each winder 6, 7 even if the tension of the wire 3 changes during processing. The rotation speed can be kept appropriate.

(Cutting method)
In this wire saw device 1, the workpiece W is set, and for example, by operating the operation switch to operate the wire saw device 1, the workpiece W can be cut by the cooperation of the wire guide drive motor 20 and the control device 8. A series of processing until completion is automatically executed.

  First, the work W is set on the table 51a (work support process). Specifically, the workpiece W is attached to the table 51a so that the cutting direction thereof is parallel to the wire group 3a. When the wire saw device 1 is operated in this manner, the supply winder 6 and the winding winder 7 perform the unwinding process and the winding process of the wire 3 in conjunction with the rotation of the wire guide 2, and the wire 3 moves forward. Repeat reverse travel (wire travel process).

  In conjunction with the travel of the wire 3, the wire guide support 4 and the like are also automatically controlled to swing by the control device 8 (swing control step). When the wire travel process and the swing control process are performed, the winder speed control program 8a and the correction program 8b are executed to control the rotational speeds of the winders 6 and 7.

  FIG. 7 shows a time chart of the rotation speeds of the winders 6 and 7 with respect to the swing angle. (A) of the figure represents a change with time of the swing angle of the wire guide support portion 4 and the like. (B) of the figure represents a change with time of the rotational speed of each of the winders 6 and 7 during forward traveling corresponding to (a). (C) of the same figure represents the time-dependent change of the rotational speed of each winder 6 and 7 at the time of reverse running corresponding to (a). In each of the diagrams (b) and (c), the upper solid line represents the change over time in the rotational speed of the supply winder 6, and the lower solid line represents the change over time in the rotational speed of the winding winder 7.

  In the time zone t1 shown in the figure, as shown in FIG. 3, the wire guide 2 and the like are displaced from the state of S1 to the state of S2 (the swinging direction is clockwise). In the time zone t2, the wire guide and the like are displaced from the state of S2 to the state of S1 (the swinging direction is counterclockwise).

  In the time zone t1, the supply-side wire travel path 14a becomes longer because the supply-side wire guide 2 moves away from the first pulley P1. On the other hand, since the winding side wire guide 2 approaches the first pulley P1, the winding side wire travel path 14b is shortened. Accordingly, in the time zone t1, the winders 6 and 7 are synchronized and controlled to have a large rotational speed during forward traveling, and the winders 6 and 7 are synchronized and controlled to have a small rotational speed during backward traveling.

  In the time zone t2, since the supply side wire guide 2 approaches the first pulley P1, the supply side wire travel path 14a becomes shorter. On the other hand, since the winding side wire guide 2 moves away from the first pulley P1, the winding side wire travel path 14b becomes long. Therefore, in the time zone t2, the winders 6 and 7 are controlled to rotate at low speeds during forward travel, and the winders 6 and 7 are controlled to rotate at high speeds during reverse travel.

  The rotational speeds of the winders 6 and 7 in each time zone t1 and t2 are controlled to a substantially constant speed. The rotation speed of each of the winders 6 and 7 is switched in the time zone (S1, S2 in FIG. 3) in which the swing angle of the wire guide support portion 4 is maximum, that is, the swing speed is the slowest. It is set to switch in the time zone. By doing so, the rotation speed can be switched stably.

  As described above, even if the length of the wire travel path 14 is changed due to the swing, the rotational speed of each of the winders 6 and 7 changes accordingly, so that the tension change of the wire 3 is effectively suppressed. Is done. As a result, the tension pulley P2 is also stabilized at the reference position, and the tension of the wire 3 can be maintained with high accuracy, so that highly accurate cutting can be realized.

  In the wire saw device 1, since the wire 3 repeats traveling while reversing the traveling direction, the tension of the wire 3 may change over time. In some cases, the tension of the wire 3 is intentionally variably controlled during the processing. In such a case, the tension pulley P2 is displaced to a position deviating from the reference position so as to have a predetermined tension.

  FIG. 8 shows the tension pulley P2. For example, when the tension of the wire 3 increases, the tension arm 11a rotates from the reference position indicated by the solid line, and as indicated by the phantom line Y1, the tension pulley P2 is the nearest pulley around which the wire 3 is continuously wound. Displacement in a direction approaching P (also referred to as + direction). Further, when the tension of the wire 3 is loosened, the tension arm 11a is rotated from the reference position, and the tension pulley P2 is separated from the nearest pulley P around which the wire 3 is continuously wound, as indicated by an imaginary line Y2. Displacement in the direction (also referred to as-direction).

  Therefore, even if the tension pulley P2 is displaced from the reference position, the correction program 8b is executed (feedback control) so that it automatically returns to the reference position and is stabilized. During machining, the displacement of the tension pulley P2 is always measured, and the measured value is input to the control device 8. The correction program 8b executes a process for correcting the rotational speed of the winders 6 and 7 based on the actually measured value.

  FIG. 9 shows a flowchart of the correction control. (A) of the figure represents the control of the supply winder 6 during forward traveling, and (b) of the figure represents the control of the winding winder 7 during forward traveling.

  The correction program 8b determines whether or not the tension pulley P2 (also referred to as supply-side tension pulley P2a) in the supply-side wire travel path 14a has been displaced in the + direction (step S1). When the supply-side tension pulley P2a is displaced in the + direction, since the wire 3 is pulled, the correction program 8b sets the rotation speed of the supply winder 6 so that the wire 3 is unwound in response. The increasing process is executed, and the supply side tension pulley P2a is returned to the reference position (step S2).

  Further, the correction program 8b determines whether or not the supply side tension pulley P2a has been displaced in the-direction (step S3). When the supply-side tension pulley P2a is displaced in the-direction, the wire 3 is loosened, so the correction program 8b reduces the rotation speed of the supply winder 6 so that the wire 3 is unwound little accordingly. The process is executed, and the supply side tension pulley P2a is returned to the reference position (step S4).

  Similarly, the correction program 8b determines whether or not the tension pulley P2 (also referred to as the winding side tension pulley P2b) in the winding side wire travel path 14b has been displaced in the + direction (step S11). When the take-up side tension pulley P2b is displaced in the + direction, the wire 3 is pulled, so the correction program 8b rotates the take-up winder 7 so as to take up the wire 3 accordingly. Is executed to return the winding side tension pulley P2b to the reference position (step S12).

  Further, the correction program 8b determines whether or not the winding side tension pulley P2b has been displaced in the-direction (step S13). When the take-up side tension pulley P2b is displaced in the-direction, the wire 3 is loosened. Therefore, the correction program 8b sets the rotation speed of the take-up winder 7 so as to wind up a large amount of the wire 3 accordingly. An increasing process is executed to return the winding side tension pulley P2b to the reference position (step S14).

  In the case of reverse traveling, the traveling direction of the wire 3 is reversed, so that the correction of the rotational speed of the winders 6 and 7 is also changed accordingly. FIG. 10 shows a table that summarizes the correction control of the rotational speeds of the winders 6 and 7 for each combination of the traveling direction of the wire 3 and the displacement direction of the tension pulley P2.

  Therefore, even if the tension of the wire 3 changes during processing, the tension pulley P2 is held at the reference position, so that the rotational speed of the winders 6 and 7 can be kept stable and appropriate. it can.

  Then, in order to press the workpiece W against the wire group 3a, the workpiece holding member 51 is displaced toward the wire group 3a traveling while being controlled to swing (displacement control step). When the workpiece W comes into contact with the traveling wire group 3a, the workpiece W is cut by the frictional resistance. At the time of cutting, oil is supplied to the cutting site of the workpiece W from an oil supply device (not shown). Until the workpiece W is divided, traveling control and swing control of the wire 3 are automatically executed.

  In addition, the wire saw apparatus etc. concerning this invention are not limited to embodiment mentioned above, The other various structure is included. The wire saw device to which the present invention is applicable is not limited to the wire saw device 1 shown in FIG. The present invention can be widely applied to a wire saw apparatus that performs a cutting process by pressing a workpiece against a wire traveling while swinging.

  For example, the tension holding mechanism 11 is not limited to the tension motor 11b and may be configured by a spring or the like. For example, a tension holding mechanism may be incorporated in the supply winder 6 or the winding winder 7. There may be three or more wire guides 2.

  The shape of the workpiece W (the shape before processing) is not particularly limited. For example, the present invention can be widely applied to a workpiece W having various shapes such as a columnar shape and a rectangular parallelepiped shape. The material of the workpiece W is not limited to silicon or the like. The cutting wire is not limited to a fixed abrasive wire, but when the workpiece W is a difficult-to-cut material such as sapphire or silicon carbide (SiC), it is preferable to use a fixed abrasive wire.

  The method of winding the wire around the wire guide, such as pulling out the wire from the opposite side of the workpiece, can be appropriately changed according to the specification.

  The wire saw device and the cutting method of the present invention are suitable for cutting a silicon ingot or the like.

DESCRIPTION OF SYMBOLS 1 Wire saw apparatus 2 Wire guide 3 Cutting wire 4 Wire guide support part 6 Supply winder 7 Winding winder 8 Control apparatus 8a Winder speed control program 8b Correction program 10 Side wall plate 11 Tension holding mechanism 50 Work holding part 61 Supply side bobbin 71 Winding Take-side bobbin P Pulley P1 First pulley P2 Tension pulley W Work A1 Oscillating shaft A2 Rotating shaft

Claims (5)

A wire saw device for cutting a workpiece by pressing the workpiece against a cutting wire that swings while traveling,
A wire guide support that swings about a swing axis in a range of a predetermined angle from a reference position substantially perpendicular to a direction in which the workpiece is pressed;
A pair of wire guides disposed on the wire guide support portion, each of which is separated from each other and rotates about a rotation axis parallel to the swing axis;
A group of substantially parallel wires formed between the wire guides by spirally winding the one cutting wire around the pair of wire guides;
A winder capable of unwinding and winding the cutting wire;
A wire travel path that is provided between the wire guide and the winder and guides the cutting wire;
A workpiece holding unit that supports the workpiece, displaces and presses the workpiece against the wire group;
A control device;
With
A wire saw device, wherein the control device includes a winder speed control means for controlling the rotational speed of the winder in synchronization with the swing of the wire guide support portion. The wire saw device according to claim 1,
When the winder is unwinding the cutting wire, the winder speed control means is configured to shorten the wire travel path when the wire guide support portion swings in the direction in which the wire travel path becomes longer. A wire saw device for controlling the winder so that the rotational speed of the winder is higher than when the wire guide support part swings. The wire saw device according to claim 2, wherein
A wire saw device in which the winder speed control means includes a preset control parameter, and controls the rotational speed of the winder based on the control parameter. The wire saw device according to claim 3,
In the wire travel path, a tension pulley is provided to keep the tension of the cutting wire constant,
The wire saw device, wherein the winder speed control means includes a correction means for controlling the rotational speed of the winder based on an actual measurement value of the displacement amount of the tension pulley. A cutting method for cutting a workpiece by pressing the workpiece against a cutting wire that swings while traveling,
A cutting method including a winder speed control step of automatically controlling a traveling speed of the cutting wire in synchronization with swinging of the cutting wire.

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