JP3489529B2 - Method of manufacturing wire for wire saw - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing 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 A wire saw travels a wire row in which wires are wound around a plurality of groove rollers at a predetermined pitch, and a material to be cut (work) is pressed against the wire row to separate the wire row from the work. It is an apparatus for cutting a work into a large number of wafers by pouring a polishing liquid in between and by a grinding action of abrasive grains.

By the way, as a characteristic required for a wire used in such a wire saw, it is important that the wire habit such as the free coil diameter of the wire, the twist, and the undulation does not change in the cutting process. After the cutting, if the diameter of the free coil becomes smaller than that in the initial stage, or if the wire has a bad wrinkle such as a minute wave (waviness), there arises a problem that the accuracy of the slice plane is significantly reduced.

Therefore, according to the present invention, even after cutting,
An object of the present invention is to provide a method for manufacturing a wire for a wire saw that maintains a good wire habit.

[0005]

The present invention provides a method for manufacturing a wire for a wire saw to be used for cutting and slicing hard materials such as silicon and solar cells through a wire drawing process. After that, the heat treatment is performed under a constant load.

Usually, when manufacturing a wire for a wire saw, the wire drawing step is the final step.

According to the present invention, after the final wire drawing step, heat treatment is further performed under a condition that a constant load is applied, so that the reduction of the wire habit after use can be suppressed without lowering the required tensile strength. It was done.

Depending on the magnitude of the tensile load applied during the heat treatment, there is little effect on the wire habit of the wire after use. Therefore, the magnitude of the tensile load applied during the heat treatment should be 5% or more of the breaking load. Also, 7
The effect is obtained even if it exceeds 0%, but if it exceeds 70%, disconnection during production is promoted, so the upper limit is 70%.
And The pulling load may be applied by utilizing the pulling force at the time of pulling, or may be applied at the time of winding by a dancer roll or the like.

The temperature of the heat treatment capable of maintaining the habit of the wire after use is preferably 100 ° C. or higher and 300 ° C. or lower, and preferably 150 ° C. or higher and 250 ° C. or lower.
In particular, at a temperature of 150 ° C. or higher, the effect of maintaining good line habit is remarkable. Further, at a temperature of 300 ° C. or higher, it becomes impossible to maintain the required tensile strength as a wire for wire saw.

The above heat treatment may be carried out when the reel is rewound after wire drawing, or after passing through the final die during wire drawing, the wire is electrically heated or brought into contact with a high temperature gas, or at a high temperature. Contact with solids, or
It may be heated by a method such as passing through a liquid constant temperature bath of oil or the like heated to a high temperature, and then wound on a reel. Considering the cost, it is preferable to perform the drawing.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A wire for a wire saw having a diameter of 0.16 mm is produced by a wire drawing process and is not heat-treated, and at a temperature of 100 to 350 ° C. under a tension of 5% to 70% of a breaking load. The silicon ingot was cut using the heat-treated one and the wire habit of the used wire was evaluated. The graph of FIG. 1 shows the relationship between the temperature of the heat treatment performed under various tensile loads and the wire habit of the wire after use. As shown in the graph of FIG. 1, the wire that has not been heat-treated has a bad line habit after use. On the other hand, the wire subjected to the heat treatment at 100 ° C. to 300 ° C. under the tensile load retains the free coil diameter of 300 mm or more after use, has no waviness, and has a good wire habit. Further, when the heat treatment is performed at a high temperature of 350 ° C., not only is the improvement in the wire habit small, but the tensile strength required as a wire for a wire saw decreases, which is not preferable. From the above, after wire drawing, 5% to 70% of the breaking load of the wire
Under the following loads, 100 to 300 ° C, preferably 150
It was confirmed that the wire heat-treated at a temperature of up to 250 ° C. had a good wire habit after use.

[0012]

According to the present invention, it is possible to manufacture a good wire saw wire which has a good wire habit even after use, holds a free coil diameter of 300 mm or more, and has no waviness.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the temperature of heat treatment performed under various tensile loads and the wire habit of a wire after use.

Front page continuation (72) Inventor Akito Hoshiba 1-1-1 Kunyokita, Itami-shi Itami Works, Sumitomo Electric Industries, Ltd. (56) Reference JP-A-8-155569 (JP, A) JP-A 10-309627 (JP, A) JP 7-3338 (JP, A) JP 10-132035 (JP, A) Patent 2957571 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) C21D 9/52-9/66 C21D 9/00-9/44 C21D 9/50

Claims (3)

(57) [Claims] 1. A through the wire drawing process, the cutting of hard materials,
In a method for manufacturing a wire saw wire used for slicing, after the wire drawing step, under a load of 5% or more and 70% or less of a breaking load of the wire, 100 ° C or more and 300 ° C
A method for manufacturing a wire for a wire saw, which comprises performing heat treatment in the following range. 2. The method for manufacturing a wire for a wire saw according to claim 1, wherein the heat treatment is performed while the wire has passed through the final die and then wound on a reel. Wherein the heat treatment, the energization of the wire, wire Ya
Blowing hot gas into contact with the roll which is maintained at a high temperature, or wire saw wire according to claim 1 or 2, characterized in that by passing line wires in a constant temperature bath of oil Manufacturing method.