JP2001259992A - Wire for wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire for a wire saw in which a surface irregularities of a material to be cut is small and which has a cutting characteristic with an extremely high accuracy. SOLUTION: In the wire for the wire saw, a free coil diameter of the wire after completion of wire drawing is set to 600 mm or more or a jump up height of the wire after completion of the wire drawing is set to 0 mm or more to 10 mm or less, preferably 5 mm or less. A turn on own axis of the wire in the case where a wire wound on a reel after completion of the wire drawing is straightly drawn is set to 0.5 turn/m or less, preferably 0.25 turn/m or less per a unit length of the wire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire for a wire saw used for cutting and slicing hard materials such as silicon and solar cells.

[0002]

2. Description of the Related Art In a wire saw, a wire row in which a wire is wound around a plurality of groove rollers at a predetermined pitch is run, and while a material to be cut (work) is pressed against the wire row, the wire row and the work are joined together. This is an apparatus that cuts a work into a large number of wafers by a grinding action of abrasive grains while pouring an abrasive liquid during the process.

Accordingly, an object of the present invention is to provide a wire for a wire saw capable of performing high-precision cutting with small surface irregularities and warpage of a surface to be cut.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to silicon,
In a wire for a wire saw used for cutting and slicing a hard material such as a solar cell, first, the free coil diameter of the wire after drawing is set to 600 mm or more.

[0005] A small coil diameter deteriorates the surface irregularities of the material to be cut at the time of cutting. This is because the straightness of the wire is impaired in the principle of a wire saw that cuts while running the wire while applying a certain tension to the wire.

Therefore, when the free coil diameter of the wire after drawing is set to 600 mm or more, the straightness of the wire is not hindered, so that the surface unevenness of the material to be cut at the time of cutting is not deteriorated.

[0007] The diameter of the free coil varies depending on the drawing direction with respect to the die at the time of wire drawing and the drawing wire drawing conditions such as back tension. In particular, the influence of the final die is extremely large, and a predetermined coil diameter can be obtained by adjusting the setting direction of the final die.
Further, since the wire for a wire saw has a small diameter, the coil diameter changes due to a change in other factors such as a back tension, so that precise wire drawing is required.

Further, in the present invention, the jump height of the wire after the completion of the drawing is set to 0 mm or more and 10 mm or less.

Here, the term “bounce” means that when a drawn wire saw wire is cut into a predetermined length and placed on a horizontal plane such as a desk or a floor, the terminal of the wire becomes its own weight. It refers to jumping up and down, and the maximum height that jumps up with respect to the horizontal plane is called "jumping height".

[0010] If the drawn wire for a wire saw has a large jump, the straightness of the wire is hindered, as in the case of the coil diameter, so that the surface unevenness of the material to be cut at the time of cutting is deteriorated.

This jump can also be controlled by adjusting the drawing conditions. Specifically, it is necessary to set the wire so that the wire does not rotate (twist) when the wire is running during wire drawing. Further, it is necessary to optimize a pass line until the wire exiting the final die is wound on a reel.

Further, in the present invention, when the wire for wire saw is pulled out from the reel and set and cut, if the wire drawn from the reel rotates (rotates), the surface irregularities of the material to be cut at the time of cutting are deteriorated. For this purpose, the rotation of the wire when the wire wound around the reel after drawing is straightened is set to 0.5 rotations / m or less per wire unit length.

This is because it is out of the question for a wire having a small coil diameter, but since the wire has a considerable coil shape, the wire is supplied while rotating.

In controlling the rotation, it is essential to optimize a pass line until the final wire is wound on a reel.

High carbon steel plated with copper or a copper alloy is suitable for a wire for a wire saw, and the above-mentioned wire habit is particularly necessary for high carbon steel used as a wire for a wire saw.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Wires having various habits were obtained from wire for a wire saw having a diameter of 0.16 mm under different drawing conditions. Using each wire, the silicon ingot was cut, and the state of the surface irregularities of the workpiece was evaluated. Table 1 shows the results. The surface condition is
Evaluation was made using the maximum value of the difference between the concave and convex portions on the surface of the cut product.
A case of 0 μm was evaluated as Δ (good), and a case exceeding 10 μm was evaluated as x (bad).

[0017]

[Table 1]

As shown in Table 1, the free coil diameter is 600 mm
With the above-mentioned wires, the cutability is good (△ or）) except for the extremely high jump height of 25 μm.

Further, in the case of a wire having a jump height of 10 mm or less, the cutability is good (△ or ○) except for a wire having a small free coil diameter of 360 mm. In particular, a wire having a jump height of 5 mm or less is extremely good (○).

In the case of a wire having a twist amount (rotation amount) of 0.5 revolutions / m or less per unit length of the wire, the cutability is good (○ or ○), except that the free coil diameter is as small as 360 mm. It is. In particular, a wire having a rate of 0.25 revolutions / m or less per wire length is extremely good (（).

From the above, in the wire for a wire saw, the free coil diameter of the wire after completion of the drawing is set to 600
mm or more, or when the jump height of the wire after drawing is set to 0 mm or more and 10 mm or less, preferably 5 mm or less, and further, the wire wound around the reel after drawing is straightened. When the wire is pulled out, the rotation of the wire is 0.5
It was confirmed that the cutting property was excellent when the rotation speed was set to not more than rotations / m, preferably not more than 0.25 rotations / m.

In particular, the free coil diameter, the jump height,
A wire whose twist amount (rotation amount) is all adjusted has extremely high cutting characteristics.

[0023]

The wire for a wire saw according to the present invention comprises:
As described above, the material to be cut has extremely high-precision cutting characteristics with small irregularities on the surface.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akito Hoshima 1-1-1, Koyokita, Itami-shi, Itami Works, Sumitomo Electric Industries, Ltd. No. 1 Sumitomo Electric Industries, Ltd. Itami Works F term (reference) 3C058 AA05 AA09 CA05 CB01 CB03 DA03 3C069 AA01 BA06 BB01 CA05 EA02

Claims (4)

[Claims] 1. Cutting of hard materials such as silicon and solar cells,
A wire for a wire saw used for slicing, wherein the free coil diameter of the wire after drawing is set to 600 mm or more. 2. Cutting of hard materials such as silicon and solar cells;
In the wire for a wire saw used for slicing, the jump height of the wire after the completion of drawing is set to 0 mm or more and 10 mm or more.
mm. 3. Cutting of hard materials such as silicon and solar cells,
In the wire for a wire saw used for slicing, the rotation of the wire when the wire wound around the reel after drawing is straightened is set to 0.5 rotation / m or less per wire unit length. And wire for wire saw. 4. The wire for a wire saw according to claim 1, wherein the wire material is a plated high carbon steel wire.