JP7687015B2 - Wire saw and cutting method - Google Patents

Description

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

Wire saws using wires with abrasive grains are used to cut workpieces such as semiconductor ingots and stone. The abrasive grains are made of hard metals or diamonds, and these grains are fixed to the wire. With such wire saws, the workpiece is cut by moving the wire in the length direction while one side of the wire is pressed against the workpiece. This causes problems such as uneven wear of the wire as processing continues, slowing down the processing speed and shortening the life of the wire. As a result, technology has been developed to use the wire evenly in the circumferential direction of its cross section.

For example, Patent Document 1 discloses a technique for a forced rotation device for a wire saw that rotates the wire about its center. This technique includes a pair of pulleys that suspend an endless wire and move it in the length direction, and a pair of crimping wheels (rollers) that clamp the wire and rotate in the direction of wire movement. It also includes a large gear that supports the pair of crimping wheels, surrounds the entire pair of crimping wheels, and rotates about the center of the pair of wires. With the above configuration, the wire can be rotated about the center of its cross section, allowing the wire to be used evenly in the circumferential direction of its cross section.

Japanese Patent Application Publication No. 03-294170

However, the technology in Patent Document 1 has a problem in that the large gear surrounds the pair of crimping wheels, and the mechanism for rotating the large gear is located outside the large gear, which results in a large device.

The present invention was made in consideration of the above problems, and aims to provide a wire saw with a compact configuration that allows the wire to be used evenly in the circumferential direction of its cross section.

In order to solve the above problems, the wire saw of the present invention has a pair of wire moving means for moving the wire in a taut state in the longitudinal direction, a first roller and a second roller arranged between the pair of wire moving means and rotating in synchronization with the movement of the wire due to the frictional force between the first roller and the second roller when the pair clamps the wire, and a roller unit having 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 direction of the rotation axis changes when the wire is clamped.

The cutting method of the present invention also involves moving a wire in a taut state in the longitudinal direction using a pair of wire moving means, and when the wire is clamped between the pair of wire moving means, the wire is clamped 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 first roller and the second roller are slid while the wire is clamped so that the positional relationship between the first roller and the second roller in the direction of the rotation axis changes.

The effect of the present invention is to provide a wire saw that has a compact configuration and can use the wire evenly in the circumferential direction of its cross section.

FIG. 1 is a schematic diagram showing a wire saw according to a first embodiment. FIG. 13 is a block diagram showing a wire saw according to a second embodiment. 13 is a schematic diagram illustrating an example of a configuration of a roller unit according to a second embodiment. FIG. FIG. 11 is a schematic diagram illustrating an example of an operation of the second embodiment. 13 is an example of a timing chart of an operation of the second embodiment. FIG. 11 is a schematic diagram showing another example of the operation of the second embodiment.

Below, an embodiment of the present invention will be described in detail with reference to the drawings. However, the embodiment described below has limitations that are technically preferable for implementing the present invention, but does not limit the scope of the invention to the following. Note that similar components in each drawing are given the same numbers, and descriptions may be omitted.

(First embodiment)
1 is a schematic diagram showing a wire saw 10 according to the present embodiment. The wire saw 10 has a pair of wire moving means 1 and a roller unit 2.

The wire moving means 1 moves the wire 9 in the longitudinal direction while keeping it taut.

The roller unit 2 has a first roller 2a and a second roller 2b that sandwich the wire 9 and rotate in the direction of movement of the wire 9 as they are pulled by the movement of the wire 9. The first roller 2a and the second roller 2b are arranged so that their respective rotation axes 2aa and 2ba are parallel. The roller unit 2 also has a slide mechanism 2c that slides the first roller 2a and the second roller 2b while sandwiching the wire 9 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.

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 moving means 1 moves the wire 9 in the length direction, thereby cutting the workpiece 20. At that 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 to change the positional relationship between them in the direction of the rotation axis. In FIG. 1, this direction is indicated by a straight double-headed arrow. With 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-mentioned twisting, the part of the wire that contacts the workpiece 9 on the outer periphery can be replaced for each period during cutting. As a result, the part of the wire 9 used for cutting can be made uniform in the circumferential direction.

As described above, in this embodiment, the rotating shafts of the first roller 2a and the second roller 2b are supported, and the slide mechanism 2c that slides these rotating shafts is simply provided at the end of the rotating shaft. Therefore, with the wire saw of this embodiment, it is possible to provide a wire saw that can use the wire evenly in the circumferential direction with a more compact configuration than the configuration of Patent Document 1 in which a circular gear wheel is provided to completely surround the two rollers.

Second Embodiment
In this 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 a wire saw 1000 of this embodiment. The wire saw 1000 has 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 an example of a pair of wire moving means 1 of the first embodiment. Also, the first roller unit 200 and the second roller unit 300 are an example of a roller unit 2.

The first reel 100 and the second reel 110 wind the abrasive wire 400. One reel supplies the abrasive wire 400, and the other reels the abrasive wire 400.

Guide pulley A120, guide pulley B130, guide pulley C140, and tension pulley 150 guide the abrasive wire 400 stretched between the first reel 100 and the second reel 110 so that it can cut the workpiece 2000. In the example of FIG. 2, the abrasive wire 400 stretched between guide pulley A120 and guide pulley B130 is configured to cut and cut the workpiece 2000. The tension pulley 150 adjusts the tension applied to the abrasive wire 400 to keep it within a specified range.

The first roller unit 200, like the roller unit 2 of the first embodiment, pinches the abrasive wire 400 and twists the abrasive wire 400. FIG. 3 is a schematic diagram showing an example of the configuration of the first roller unit 200. The first roller unit 200 has a first roller 210 and a second roller 220. The first roller 210 and the second roller 220 are made of a material that can provide a large friction force between the abrasive wire 400 and the abrasive wire 400 so that the abrasive wire 400 can be pinched without slipping. Specifically, soft plastic, rubber, hard sponge, etc. can be used. One example is polyurethane. The first roller 210 is supported by a first shaft 211, and the second roller 220 is supported by a second shaft 221. The first roller 210 and the second roller 220 rotate smoothly by the movement of the abrasive wire 400 pinched between them. To ensure smooth rotation of the first roller 210 and the second roller 220, general-purpose technology can be applied, such as using bearings as bearings.

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

When the wire saw 1000 is operated, the first roller 210 and the second roller 220 sandwich the abrasive wire 400 between them in the above configuration. When the abrasive wire 400 moves in the length 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 impede the movement of the abrasive wire 400. The first roller 210 and the second roller 220 slide against each other in the axial direction by the slide mechanism 230. This operation twists the abrasive wire 400.

Figure 4 is a schematic diagram showing an example of the operation of the first roller unit 200. Figure 4(a) shows a state in which the first roller 210 and the second roller 220 are controlled to the same height. Here, the amount of twisting of the abrasive wire 400 in this state is assumed to be zero. Figure 4(b) is a schematic diagram showing a state in which the first roller 210 is slid up and the second roller 220 is slid down by the slide mechanism 230. In this state, the abrasive wire 400 twists clockwise in Figure 4. Figure 4(c) is a schematic diagram showing a state in which the first roller 210 is slid down and the second roller 220 is slid up, the opposite of Figure 4(b). In this state, the abrasive wire 400 twists counterclockwise in Figure 4.

The second roller unit 300 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 and the amount of twist applied to the abrasive wire 400 by the second roller unit 300 can be made the same. In this way, 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. This allows the portion where the abrasive wire 400 abuts against the workpiece 2000 to be controlled to a desired position on the cross section of the abrasive wire 400. By appropriately switching the location on the cross section where the abrasive wire 400 abuts against the workpiece 2000 through this control, the abutment location can be made uniform around the cross section. Specifically, for example, by alternating between the states of FIG. 4(a), (b), and (c) for a specified period or for a specified wire feed amount, the contact portion between the cross section of the abrasive wire 400 and the workpiece 2000 can be made uniform.

Figure 5 is a timing chart showing an example of the above-mentioned replacement operation. Figure 5 shows the relationship between the feed speed of the abrasive wire 400 and the twist amount of the abrasive wire 400. In this example, the control is performed to change the twist amount of the abrasive wire 400 for each predetermined period of the abrasive wire 400. The feed amount is defined as the direction in which the abrasive wire 400 is fed from the first reel 100 and wound on the second reel 110 as positive, and the opposite direction as negative. The control is performed to change the twist amount by 90° each time one set of periods in which the abrasive wire 400 is fed in the positive direction and the negative direction is completed. The control is performed to change from 0° to 90°, 180°, and 270°, and to return to 0° after 270°. By performing such control, the area where the abrasive wire 400 hits the workpiece 2000 can be equalized, and the area where the abrasive wire 400 is worn 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, the amount of twist may be controlled to change continuously like a sine wave.

As described above, by controlling the amount of twisting of the first roller unit 200 and the second roller unit 300 to be synchronized, the abrasive wire 400 between the first roller unit 200 and the second roller unit 300 can be made to be in a state without twisting. However, if cutting is continued, the abrasive wire 400 between the first roller unit 200 and the second roller unit 300 may become twisted. 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 pinching of the abrasive wire 400 by the first roller 210 and the second roller 220 can be released. The same operation is also performed in the second roller unit 300. These operations temporarily remove any twisting in the abrasive wire 400. After the twisting is removed, the abrasive wire 400 is clamped again between the first roller unit 200 and the second roller unit 300, allowing the amount of twisting of the abrasive wire 400 to be controlled once again.

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 this is not limited to the above. For example, the first roller unit 200 may be provided between the guide pulley A120 and the guide pulley B130, near the guide pulley A120, or between the guide pulley A120 and the guide pulley B130, near the guide pulley B130. Also, three or more roller units may be arranged.

As described above, in the wire saw 1000 of this embodiment, the rotation shafts of the first roller 210 and the second roller 220 are supported, and the slide mechanism 230 for sliding these rotation shafts is simply provided at the end of the rotation shaft. Therefore, with the wire saw of this embodiment, it is possible to prevent uneven wear of the abrasive wire and equalize the amount of wear of the abrasive wire in the circumferential direction with a more compact configuration than the configuration of Patent Document 1 in which a circular large gear is provided to completely surround the two rollers.

The present invention has been described above using the first and second embodiments as exemplary examples. However, the present invention is not limited to the above-mentioned embodiments. In other words, the present invention can be applied in various aspects that can be understood by a person skilled in the art within the scope of the present invention.

REFERENCE SIGNS LIST 1 Wire moving means 2 Roller unit 9 Wire 20, 2000 Workpiece 100 First reel 110 Second reel 200 First roller unit 300 Second roller unit 400 Abrasive wire 1000 Wire saw

Claims (7)

a pair of wire moving means for moving the wire in a longitudinal direction while the wire is tensioned;
a roller unit including a first roller and a second roller disposed between the pair of wire moving means, the first roller and the second roller rotating in synchronization with the movement of the wire due to frictional force between the first roller and the second roller when the first roller and the second roller sandwich the wire, and a slide mechanism for sliding the first roller and the second roller so that a positional relationship between the first roller and the second roller in a rotation axis direction changes while the wire is sandwiched;
having
The sliding is performed each time a set of periods, which includes a period during which the wire moving means moves the wire in one direction in the length direction of the wire and a period during which the wire moving means moves the wire in the other direction, is completed.
A wire saw comprising: The roller unit is
a spacing means for spacing the first roller and the second roller apart;
2. The wire saw according to claim 1 . The roller unit has two sets of the roller units.
3. The wire saw according to claim 1 or 2. The two sets of roller units are slid synchronously.
4. The wire saw according to claim 3. The wire moving means
A pair of reels for winding, unwinding, and winding the wire are provided.
5. The wire saw according to claim 1, wherein the wire saw is a ferroelectric material. The wire moving means
A pair of pulleys that move the endless wire.
5. The wire saw according to claim 1, wherein the wire saw is a ferroelectric material. A pair of wire moving means moves the wire in a longitudinal direction while keeping it taut;
When the wire is sandwiched between the pair of wire moving means, the wire is sandwiched between a first roller and a second roller which rotate in synchronization with the movement of the wire due to a frictional force between the wire and the first roller and a second roller;
With the wire sandwiched between them, the first roller and the second roller are slid so that a positional relationship between the first roller and the second roller in a rotation axis direction changes ;
The sliding is performed each time a set of periods, which includes a period during which the wire moving means moves the wire in one direction in the length direction of the wire and a period during which the wire moving means moves the wire in the other direction, is completed.
A cutting method comprising the steps of:

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