Wire saw and cutting method

Abstract

To provide a wire saw making it possible to use a wire uniformly in a circumferential direction thereof with a compact configuration.SOLUTION: A wire saw 10 includes a pair of wire movement means 1 to move a wire 9 in a tensioned state in a length direction, a first roller 2a and a second roller 2b which are disposed between the pair of wire movement means 1 and hold the wire 9 therebetween by forming a pair, and which rotates in synchronization with movement of the wire 9 by a frictional force between them and the wire 9, and a roller unit 2 having a slide mechanism 2c to slide the first roller 2a and the second roller 2b with the wire 9 held therebetween so as to change a positional relationship between the first roller 2a and the second roller 2b in rotation axes 2aa and 2ba.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wire saw and a cutting method.

Background Art

[0002] For cutting workpieces such as semiconductor ingots and stones, a wire saw using a wire with abrasive grains is used. The abrasive grains are made of hard metals, diamonds, etc., and these abrasive grains are fixed to the wire. In such a wire saw, the workpiece is cut by moving the wire in the length direction while pressing one side of the wire against the workpiece. Therefore, when the processing continues, there is a problem that the wire is consumed on one side, the processing speed decreases, and the life of the wire becomes short. Therefore, techniques for evenly using the circumferential direction of the cross-section of the wire have been developed.

[0003] For example, Patent Document 1 discloses a technique of a forced rotation device for a wire saw that rotates a wire about its center. In this technique, a pair of pulleys that suspend an endless wire and move it in the length direction, and a pair of pressure wheels (rollers) that sandwich the wire and rotate in the moving direction of the wire are provided. Further, a large gear that supports the pair of pressure wheels, surrounds the entire pair of pressure wheels, and rotates with respect to the center of the pair of wires is provided. With the above configuration, since the wire can be rotated about the center of its cross-section, the wire can be evenly used in the circumferential direction of its cross-section.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technology of Patent Document 1, since the large gear surrounds the entire pair of crimping wheels and further has a mechanism for rotating the large gear on the outside of the large gear, there is a problem that the device becomes large-sized.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a wire saw having a compact configuration and capable of uniformly using a wire in the circumferential direction of its cross section.

Means for Solving the Problems

[0007] In order to solve the above problems, the wire saw of the present invention includes a pair of wire moving means for moving a wire in a length direction in a stretched state, and is disposed between the pair of wire moving means, and when the wire is sandwiched in a pair, a first roller and a second roller that rotate in synchronization with the movement of the wire due to the frictional force between the wire and the wire, and in a state where the wire is sandwiched, the first roller and the second roller are slid so that the positional relationship between the first roller and the second roller in the rotation axis direction changes. And a roller unit having a slide mechanism.

[0008] Further, the cutting method of the present invention is to move a wire in a length direction in a stretched state by a pair of wire moving means, and when the wire is sandwiched in a pair between the pair of wire moving means, the wire is sandwiched by a first roller and a second roller that rotate in synchronization with the movement of the wire due to the frictional force between the wire and the wire, and in a state where the wire is sandwiched, the first roller and the second roller are slid so that the positional relationship between the first roller and the second roller in the rotation axis direction changes.

Effects of the Invention

[0009] The effect of the present invention is that it is possible to provide a wire saw having a compact configuration and capable of uniformly using a wire in the circumferential direction of its cross section.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, although the embodiments described below have technically preferable limitations for carrying out the present invention, the scope of the invention is not limited thereto. The same components in each drawing may be denoted by the same reference numerals, and the description thereof may be omitted.

[0012] (First Embodiment) FIG. 1 is a schematic diagram showing a wire saw 10 of the present embodiment. The wire saw 10 has a pair of wire moving means 1 and a roller unit 2.

[0013] The wire moving means 1 moves in the length direction with the wire 9 stretched.

[0014] The roller unit 2 has a first roller 2a and a second roller 2b that sandwich the wire 9 and rotate in the moving direction of the wire 9 being dragged by the movement of the wire 9. The first roller 2a and the second roller 2b are arranged such that their respective rotation axes 2aa and 2ba are parallel. Further, the roller unit 2 has a slide mechanism 2c that slides the first roller 2a and the second roller 2b in a state where the wire 9 is sandwiched so that the positional relationship between the first roller 210 and the second roller 220 in the axial direction of the rotation axes 2aa and 2ba changes.

[0015] In the above configuration, the workpiece 20 to be cut is pressed against the wire 9 stretched between the wire moving means 1 and the roller unit 2, and the wire 9 is moved in the longitudinal direction by the wire moving means 1, so that the workpiece 20 can be cut and cut. At this time, the wire 9 is sandwiched between the first roller 2a and the second roller 2b. Then, when a predetermined period has elapsed since the start of cutting or when the wire 9 has been fed a predetermined length, the first roller 2a and the second roller 2b are slid so as to change the positional relationship between the two in the direction of the rotation axis. In FIG. 1, this direction is indicated by double arrows on a straight line. By this operation, the wire 9 twists about the center of the wire 9. By repeating the feeding movement of the wire 9 and the above-described twisting, the portion of the wire 9 that contacts the workpiece 9 on the outer peripheral portion of the wire can be replaced for each period during cutting. As a result, the portions used for cutting the wire 9 can be equalized in the circumferential direction.

[0016] As described above, in the present embodiment, only the slide mechanism 2c that supports the rotation axes of the first roller 2a and the second roller 2b and slides these rotation axes is provided at the ends of the rotation axes. Therefore, according to the wire saw of the present embodiment, a wire saw having a compact configuration compared to the configuration of Patent Document 1 in which a circular large gear surrounding the entire two rollers is provided and capable of evenly using the wire in the circumferential direction can be provided.

[0017] (Second Embodiment) In the present embodiment, a specific configuration example of a wire saw having the basic configuration of the first embodiment will be described. FIG. 2 is a block diagram showing the wire saw 1000 of the present embodiment. The wire saw 1000 includes a first reel 100, a second reel 110, a guide pulley A 120, a guide pulley B 130, a guide pulley C 140, a tension pulley 150, a first roller unit 200, and a second roller unit 300. Here, the first reel 100 and the second reel 110 are examples of the pair of wire moving means 1 in the first embodiment. Further, the first roller unit 200 and the second roller unit 300 are examples of the roller unit 2.

[0018] The first reel 100 and the second reel 110 wind the abrasive wire 400. Then, one performs an operation of supplying the abrasive wire 400, and the other performs an operation of taking up the abrasive wire 400.

[0019] The guide pulley A120, the guide pulley B130, the guide pulley C140, and the tension pulley 150 guide the abrasive wire 400 stretched between the first reel 100 and the second reel 110 so that the workpiece 2000 can be cut. In the example of FIG. 2, the workpiece 2000 is cut and cut by the abrasive wire 400 stretched between the guide pulley A120 and the guide pulley B130. The tension pulley 150 adjusts the tension so as to keep the tension applied to the abrasive wire 400 within a predetermined range.

[0020] The first roller unit 200 sandwiches the abrasive wire 400 and twists the abrasive wire 400 in the same manner as the roller unit 2 of the first embodiment. FIG. 3 is a schematic diagram showing an example of the configuration of the first roller unit 200. The first roller unit 200 includes a first roller 210 and a second roller 220. As the material of the first roller 210 and the second roller 220, a material that can obtain a large frictional force with the abrasive wire 400 so as to sandwich the abrasive wire 400 without slipping is used. Specifically, soft plastic, rubber, hard sponge, etc. can be used. As an example, polyurethane can be mentioned. The first roller 210 is pivotally supported by a first shaft 211, and the second roller 220 is pivotally supported by a second shaft 221. The first roller 210 and the second roller 220 are configured to rotate smoothly by the movement of the abrasive wire 400 sandwiched between them. In order to make the rotation of the first roller 210 and the second roller 220 smooth, general-purpose techniques such as using bearings as bearings can be applied.

[0021] Further, the first roller 210 and the second roller 220 are supported by a slide mechanism 230. The slide mechanism 230 slides both of them so as to change the positional relationship between the first roller 210 and the second roller 220 in the rotation axis direction.

[0022] In the operation of the wire saw 1000, with the above configuration, the first roller 210 and the second roller 220 sandwich the wire 400 with abrasive grains therebetween. Then, when the wire 400 with abrasive grains moves in the longitudinal direction, the first roller 210 and the second roller 220 rotate around the first shaft 211 and the second shaft 221, respectively, so as not to interfere with the movement of the wire 400 with abrasive grains. And the first roller 210 and the second roller 220 slide axially relative to each other by the slide mechanism 230. By this operation, the wire 400 with abrasive grains is twisted.

[0023] FIG. 4 is a schematic diagram showing an example of the operation of the first roller unit 200. FIG. 4(a) shows a state where the first roller 210 and the second roller 220 are controlled to be at the same height. Here, it is assumed that the amount of twist of the wire 400 with abrasive grains in this state is zero. FIG. 4(b) is a schematic diagram showing a state where the first roller 210 is slid upward and the second roller 220 is slid downward by the slide mechanism 230. In this state, the wire 400 with abrasive grains twists clockwise in FIG. 4. FIG. 4(c) is a schematic diagram showing a state where, contrary to FIG. 4(b), the first roller 210 is slid downward and the second roller 220 is slid upward. In this state, the wire 400 with abrasive grains twists counterclockwise in FIG. 4.

[0024] The second roller unit 300 also operates in the same manner as the first roller unit 200. For example, the amount of twist applied to the abrasive wire 400 by the first roller unit 200 can be made the same as the amount of twist applied to the abrasive wire 400 by the second roller unit 300. By doing so, the amount of twist of the abrasive wire 400 stretched between the guide pulley A120 and the guide pulley B130 between the first roller unit 200 and the second roller unit 300 can be made uniform. Thereby, the portion where the abrasive wire 400 contacts the workpiece 2000 can be controlled to a desired position in the cross-section of the abrasive wire 400. By this control, if the location in the cross-section where the abrasive wire 400 contacts the workpiece 2000 is appropriately switched, the contact location can be equalized around the circumference of the cross-section. Specifically, for example, by switching the states of FIGS. 4(a), (b), and (c) at predetermined intervals or for each predetermined wire feed amount, the contact portion of the abrasive wire 400 with the workpiece 2000 in the cross-section can be equalized.

[0025] FIG. 5 is a timing chart showing an example of the above switching operation. FIG. 5 shows the relationship between the feed speed of the abrasive wire 400 and the amount of twist of the abrasive wire 400. In this example, control is performed to change the amount of twist of the abrasive wire 400 every predetermined period of the abrasive wire 400. The feed amount is defined such that the direction of feeding the abrasive wire 400 from the first reel 100 and winding it up by the second reel 110 is positive, and the reverse is negative. And every time a set of a period of feeding the abrasive wire 400 in the positive direction and a period of feeding it in the negative direction is completed, control is performed to change the amount of twist by 90° each time. It is changed from 0° to 90°, 180°, 270°, and after 270°, it is controlled to return to 0°. By performing such control, the location where the abrasive wire 400 hits the workpiece 2000 can be equalized, and the location where the abrasive wire 400 wears can be equalized. Note that the above control is merely an example, and the control for equalizing wear is not limited to the above example. For example, control may be performed such that the amount of twist changes continuously like a sine wave.

[0026] As described above, by controlling the twisting amounts of the first roller unit 200 and the second roller unit 300 to be synchronized, the abrasive grain wire 400 between the first roller unit 200 and the second roller unit 300 can be made in a non-twisted state. However, when cutting continues, twisting may occur in the abrasive grain wire 400 between the first roller unit 200 and the second roller unit 300. In preparation for such a case, it is advisable to provide the slide mechanism 230 with a mechanism for separating the first roller 210 and the second roller 220. FIG. 6 is a schematic diagram showing the operation of the first roller unit 200 provided with this mechanism. By using the above mechanism to separate the first roller 210 and the second roller 220 as shown by the arrows in the figure, the clamping of the abrasive grain wire 400 by the first roller 210 and the second roller 220 can be released. Also, in the second roller unit 300, the same operation is performed. By these operations, the twisting of the abrasive grain wire 400 is once eliminated. And after eliminating the twisting, the first roller unit 200 and the second roller unit 300 again clamp the abrasive grain wire 400, so that the control of the twisting amount of the abrasive grain wire 400 can be performed again.

[0027] In the above description, the first roller unit 200 and the second roller unit 300 are respectively arranged between the guide pulley A120 and the tension pulley 150, and between the guide pulley B130 and the second reel 110, but it is not limited to this. For example, the first roller unit 200 may be provided near the guide pulley A120 between the guide pulley A120 and the guide pulley B130, or near the guide pulley B130 between the guide pulley A120 and the guide pulley B130. Also, three or more roller units may be arranged.

[0028] As described above, in the wire saw 1000 of the present embodiment, only the slide mechanism 230 that supports the rotation shafts of the first roller 210 and the second roller 220 and slides these rotation shafts is provided at the ends of the rotation shafts. Therefore, according to the wire saw of the present embodiment, compared with the configuration of providing a circular large gear that surrounds the entire two rollers in Patent Document 1, it has a more compact configuration, prevents the wear of one side of the wire with abrasive grains, and can equalize the consumption amount of the wire with abrasive grains in the circumferential direction.

[0029] As described above, the present invention has been described by taking the first to second embodiments as exemplary examples. However, the present invention is not limited to the above embodiments. That is, within the scope of the present invention, various aspects understandable by those skilled in the art can be applied.

Explanation of Reference Numerals

[0030] 1 Wire movement means 2 Roller unit 9 Wire 20, 2000 Workpiece 100 First reel 110 Second reel 200 First roller unit 300 Second roller unit 400 Wire with abrasive grains 1000 Wire saw

Claims

1. A pair of wire moving means for moving in the longitudinal direction with the wire stretched; A first roller and a second roller which are arranged between the pair of wire moving means and rotate in synchronization with the movement of the wire due to the frictional force between the wire and the wire when the wire is sandwiched therebetween, and a slide mechanism for sliding the first roller and the second roller so that the positional relationship between the first roller and the second roller in the rotational axis direction changes while the wire is sandwiched; a roller unit having; having; The sliding is performed every time a set period of a period in which the wire moving means moves the wire in one direction in the longitudinal direction of the wire and a period in which the wire moving means moves the wire in the other direction is completed. A wire saw characterized by the above.

2. The roller unit has a separating means for separating the first roller and the second roller. The wire saw according to claim 1, characterized by the above.

3. having two sets of the roller units; The wire saw according to claim 1 or 2, characterized by the above.

4. The sliding of the two sets of the roller units is performed synchronously. The wire saw according to claim 3, characterized by the above.

5. The wire moving means has a pair of reels for winding, feeding out, and winding up the wire. The wire saw according to any one of claims 1 to 4, characterized by the above.

6. The wire moving means is a pair of pulleys for moving the endless wire. The wire saw according to any one of claims 1 to 4, characterized by the above.

7. A pair of wire moving means for moving in the longitudinal direction with the wire stretched, clamping the wire between a first roller and a second roller that rotate in synchronization with the movement of the wire due to the frictional force between the wire and the wire when the wire is clamped between the pair of wire moving means, sliding the first roller and the second roller so that the positional relationship between the first roller and the second roller in the rotational axis direction changes while the wire is clamped, The sliding is performed every time a set period of a period in which the wire moving means moves the wire in one direction in the longitudinal direction of the wire and a period in which the wire moving means moves the wire in the other direction is completed. A cutting method characterized by the above.

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