JP5347801B2 - Wire saw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller for a wire saw having a groove allowing reuse of the roller, while suppressing groove skipping of a wire. <P>SOLUTION: This roller for the wire saw has a plurality of peripheral direction grooves formed in a peripheral direction. In the roller, an angle formed by a peripheral surface of the roller and a groove wall of the peripheral direction groove is 90&deg;, as viewed from a plane including a rotation axis of the roller, and a depth of the peripheral direction groove is 0.83 to 3 times as large as a groove width of the peripheral direction groove. In this case, it is desirable that the peripheral direction groove has a cross section of a U-shape. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to a wire saw using a wire saw roller used in the guide wire in the wire saw for cutting a variety of hard materials such as the pillar-shaped silicon ingot, in particular, the peripheral surface of the roller after used for a predetermined time The present invention relates to a wire saw using a wire saw roller that can be reused by scraping until a groove disappears and re-grooving.

  Conventionally, silicon wafers for solar cells (solar wafers) are manufactured by slicing a silicon ingot manufactured using an electromagnetic casting method or a Czochralski method into a wafer, followed by cleaning. As a method of slicing the silicon ingot, a cutting method using a multi-wire saw that can obtain a wafer with good thickness accuracy is used.

  In this cutting method using a multi-wire saw, the wire supplied from the wire feeding bobbin has a plurality of circumferential grooves (grooves arranged at a predetermined pitch along the circumferential direction on the circumferential surface of the roller). By running along the groove of each grooved roller (main roller), a wire row with a predetermined interval is formed, and the work piece such as a silicon ingot is pressed against the wire row so that the work piece is flat. Disconnected. In addition, as a main roller, what wound urethane rubber around the metal core is generally used.

  Here, since the thinning of solar wafers has been progressing in recent years, the pitch of the circumferential grooves has been shortened (for example, 350 μm or less, particularly as a main roller for a multi-wire saw used in the manufacture of solar wafers. The main roller is required. This is because the interval between the circumferential grooves adjacent to each other in the rotation axis direction of the main roller is directly related to the thickness of the wafer obtained by cutting the workpiece with a wire.

  By the way, as for the main roller used conventionally, it is common that the cross-sectional shape of the circumferential direction groove | channel has comprised V shape. However, in order to reduce the pitch in the main roller having a circumferential groove having a V-shaped cross section, it is necessary to make the V-shaped opening angle an acute angle. On the other hand, if the V-shaped opening angle is made an acute angle, the groove Because the distance between the walls becomes shorter, the entire wire does not fit in the groove, the wire moves out of the groove and moves to the next groove while using the wire saw, and the workpiece with the desired thickness cannot be cut, There was a problem that the wire was twisted and disconnected.

  On the other hand, by forming a groove having a U-shaped cross section in the circumferential direction of the roller, a roller has been developed that makes it difficult for the wire to come off the groove and suppresses the occurrence of disconnection troubles ( For example, see Patent Document 1).

JP 2008-126341 A

  However, in the wire saw roller formed with the U-shaped groove, the deep U-shaped groove is formed to prevent the wire from jumping out of the groove (groove jumping). When the groove was worn by use, it was difficult to recycle by scraping the peripheral surface of the roller.

  Therefore, a wire saw roller having a groove that enables reuse of the roller while suppressing the groove jump of the wire has been demanded.

This invention is intended to be advantageously solve the above problems, Waiyaso chromatography of the present invention, meet a wire saw using a plurality of circumferential grooves are formed wire saw roller in the circumferential direction Te, wherein the peripheral surface of the wire saw roller, the angle between the circumferential groove of the groove wall, is 90 degrees as viewed in a plane containing the axis of rotation of the wire saw roller, the depth of the circumferential groove Is 0.83 to 3 times the groove width of the circumferential groove and 1 to 3 times the wire diameter of the wire wound around the circumferential groove, and the width of the circumferential groove is wound around the circumferential groove. It is 1 to 1.2 times the wire diameter of the wire, the arrangement pitch of the circumferential grooves is 350 μm or less, and the circumferential grooves are grooves having a U-shaped cross section . Thus, if the angle formed by the circumferential surface of the roller and the groove wall of the circumferential groove is 90 degrees, the pitch can be reduced while ensuring the thickness of the roller portion existing between adjacent circumferential grooves. Can do. Moreover, by making the depth of the circumferential groove 0.83 times or more the groove width of the circumferential groove, it is possible to suppress the occurrence of groove jumping of the wire. Furthermore, by setting the depth of the circumferential groove to be not more than 3 times the groove width of the circumferential groove, after the roller has been used for a predetermined time, the circumferential surface of the roller is scraped until there is no groove, and the groove is cut again. The roller can be reused.

Furthermore, when the cross-sectional shape of the circumferential groove is U-shaped, the wire is uniformly in contact with the groove bottom, so that the circumferential groove is not shaved unevenly during use. Further, the groove having a U-shaped cross section can be easily formed.

According to the wire saw using the wire saw roller of the present invention, the roller can be reused while suppressing the jumping of the groove of the wire.

It is a perspective view which shows an example of the roller for wire saws of this invention. It is an expanded sectional view of the part II enclosed with the broken line of FIG. (A) is explanatory drawing which shows a mode that a square pillar-shaped silicon ingot is cut | disconnected with the multi-wire saw using two rollers, (b) is a square-wire silicon ingot with a multi-wire saw using three rollers. It is explanatory drawing which shows a mode that it cut | disconnects. (A) is explanatory drawing which shows the state which the groove | channel wall of the circumferential groove | channel was worn out by the driving | running | working of the wire in the roller using the circumferential groove | channel of the conventional V-shaped cross section, and (b) is this It is explanatory drawing which shows the state which the groove | channel bottom of the circumferential groove | channel was abraded by the driving | running | working of the wire in the roller using the U-shaped circumferential groove | channel which concerns on invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The roller for a wire saw of the present invention has a plurality of grooves whose depth is 0.83 to 3 times the groove width in the circumferential direction, and an angle formed by the circumferential surface of the roller and the groove wall of the circumferential groove. Is 90 degrees when viewed in a plane including the rotation axis of the roller.

  Here, an example of the roller for wire saws of the present invention is shown in FIG. The wire saw roller 10 includes a cylindrical core body 11 and a hollow cylindrical groove forming portion 12 formed integrally with the core body 11. The groove forming portion 12 is formed with a plurality of circumferential grooves 13 around which wires are wound.

  The core body 11 is made of, for example, a metal such as stainless steel, and a groove forming portion 12 made of urethane is formed integrally with the core body 11 on the outer peripheral surface of the core body 11. The groove forming portion 12 can be formed according to a conventional method.

  The circumferential groove 13 formed in the groove forming portion 12 has a U-shaped cross section in the width direction and a depth of D as shown in FIG. The groove width is W. Here, the circumferential grooves 13 are arranged at a predetermined pitch P, and the angle α formed between the roller circumferential surface 14 and the groove wall 15 of the circumferential groove 13 is a cross-section in the width direction of the circumferential groove 13 (roller And 90 degrees when viewed in a plane including the rotation axis R. The depth D refers to the distance from the groove bottom 16 to the groove opening, and the pitch P refers to the distance between the centers in the width direction of adjacent grooves. Incidentally, the circumferential groove 13 can be formed in the groove forming portion 12 by pressing a U-shaped die against the fixed roller at an interval F to cut the roller.

  And the roller 10 for wire saw mentioned above can wind a wire around the circumferential groove | channel 13, and can be used for the cutting | disconnection (manufacture of a solar wafer) of a columnar silicon ingot, for example. Specifically, as shown in FIG. 3 (a) or (b), the wire 20 supplied from a wire supply bobbin (not shown) is wound around the circumferential groove 13 of the wire saw roller 10 arranged in a straight line or a triangle. While being hung, the wire saw roller 10 is rotated by a driving means (not shown), and the square columnar silicon ingot 30 is pressed against the traveling wire 20 to cut the rectangular columnar silicon ingot 30 to obtain a flat wafer. Can be obtained. In addition, as the wire 20, you may use any wire of a loose abrasive wire and a fixed abrasive wire. Moreover, the roller 10 for wire saws can be arrange | positioned in arbitrary shapes, such as a square, besides a straight line and a triangle.

  Here, the groove wall and the groove bottom of the circumferential groove 13 of the wire saw roller 10 are gradually scraped with use (running of the wire 20). Therefore, after the wire saw roller 10 has been used for a predetermined time (for example, 800 to 1000 hours), the peripheral surface of the roller is scraped, for example, by 3 to 4 mm using a super steel tool or the like, and the groove is cut again. It is used for reuse. In addition, in the conventional wire saw roller having a V-shaped groove cross section, the groove cross-sectional shape before running the wire is shown by a broken line and the groove cross-sectional shape after running the wire is shown by a solid line in FIG. In many cases, the groove wall of the circumferential groove 41 is worn and shaved due to running, but in the roller for a wire saw according to the present invention, the circumferential groove has a U-shaped cross section, so the groove is shaved and shaved. hard. If the groove cross-sectional shape is V-shaped, as shown in FIG. 4A, the angle formed by the groove wall 42 and the roller peripheral surface 43 is larger than 90 degrees, and the adjacent circumferential grooves Since the distance between the groove peripheries is shortened, the shape retention of the groove is lowered. However, if the groove cross-sectional shape is U-shaped, as shown in FIG. 4B, the groove wall 45 and the roller peripheral surface 46 This is because the angle formed between the grooves is 90 degrees and the distance between the peripheral edges of the adjacent circumferential grooves is increased, so that the shape retention of the grooves is improved.

  In addition, from the viewpoint of reusing the wire saw roller 10, the depth D of the circumferential groove 13 is preferably 0.83 to 3 times the groove width W of the circumferential groove, and is used. The wire diameter is preferably 1 to 3 times the wire diameter. It is because the groove jump of a wire can be prevented by making D 0.83 times or more of W and / or wire diameter or more. Moreover, it is because a roller can be reused sufficient number of times by making D 3 times or less of W and / or 3 times or less of a wire wire diameter. Further, from the viewpoint of ensuring sufficient strength of the groove wall, the distance F between the peripheral portions of the adjacent circumferential grooves is preferably 100 μm or more, and more preferably as wide as possible. The width W of the circumferential groove is preferably 1 to 1.2 times the wire diameter of the wire to be used, and more preferably 1.1 to 1.2 times.

  In addition, the roller for wire saws of this invention is not limited to the said embodiment at all, and can change it suitably.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to the following Example at all.

(Examples 1-3, Comparative Examples 1-3)
With the design specifications shown in Table 1, a wire saw roller (core: stainless steel, groove forming part: urethane) having a shape as shown in FIG. 1 is produced, and free abrasive wire (diameter: 0.13 mm) The columnar silicon ingot was cut 100 times using. Then, it was evaluated whether or not the wire grooving occurred (probability of grooving). In addition, after cutting the columnar silicon ingot 100 times, the roller surface is shaved with a super steel bite, the circumferential groove of the design specifications shown in Table 1 is formed again, and the operation of cutting the columnar silicon ingot again is repeated. We evaluated how many times it could be reused. The results are shown in Table 1.

  From Table 1, it can be seen that if the depth of the circumferential groove is 0.83 to 3 times the groove width of the circumferential groove, the roller can be reused while suppressing the occurrence of groove jumping. Moreover, it turns out that the frequency | count of reuse of a roller can be increased.

DESCRIPTION OF SYMBOLS 10 Roller 11 Core 12 Groove formation part 13 Groove 14 Circumferential surface 15 Groove wall 16 Groove bottom 20 Wire 30 Silicon ingot 41 Groove 42 Groove wall 43 Peripheral surface 44 Groove 45 Groove wall 46 Circumferential surface

Claims (1)

A wire saw using a wire saw roller in which a plurality of circumferential grooves are formed in the circumferential direction,
The angle formed by the circumferential surface of the wire saw roller and the groove wall of the circumferential groove is 90 degrees when viewed in a plane including the rotation axis of the wire saw roller,
The circumferential groove depth is 0.83 to 3 times the groove width of the circumferential groove and 1 to 3 times the wire diameter of the wire wound around the circumferential groove;
The width of the circumferential groove is 1 to 1.2 times the wire diameter of the wire wound around the circumferential groove,
An arrangement pitch of the circumferential grooves is 350 μm or less,
The wire saw, wherein the circumferential groove is a groove having a U-shaped cross section .