KR20110034222A

KR20110034222A - Method for manufacturing saw wire and saw wire manufactured therefrom

Info

Publication number: KR20110034222A
Application number: KR1020090091680A
Authority: KR
Inventors: 이창우
Original assignee: 주식회사 효성
Priority date: 2009-09-28
Filing date: 2009-09-28
Publication date: 2011-04-05

Abstract

Embodiments of the present invention relate to a method of manufacturing a saw wire used for cutting hard materials such as a single crystal ingot for a semiconductor wafer, a wafer for a solar cell, a precious metal, and a saw wire manufactured therefrom, and more specifically, to a fine electrolysis after a final drawing step. The present invention relates to a method for producing a saw wire having a low surface roughness by reducing a bending deviation of a wire surface by performing a polishing process, and a saw wire manufactured therefrom.

Description

Method for manufacturing saw wire and saw wire manufactured therefrom {Method for Manufacturing Saw Wire and Saw Wire Manufactured Therefrom}

Embodiments of the present invention relate to a method of manufacturing a saw wire mounted on a sawing machine and used for cutting hard materials such as a single crystal ingot for a semiconductor wafer, and a sawe wire manufactured therefrom, and more specifically, The present invention relates to a method of manufacturing a saw wire having a low surface roughness, which prevents disconnection during cutting of the cut single member and to improve the cut surface quality of the cut single member, and a saw wire manufactured therefrom.

In general, saw wire is used for cutting hard materials such as magnetic head chips or single crystal ingots for semiconductor wafers. The saw wire cut | disconnects a to-be-processed object by running, contacting to a to-be-adjusted object with the grinding liquid which mixed grinding particles, such as a silicon carbide powder and a diamond powder, and a lubricant, such as an oil.

The saw wire is made of high carbon steel wire having a high strength of 3300MPa to 4500MPa and a diameter of 0.08mmΦ to 0.3mmΦ to withstand the high tension received during grinding. Furthermore, it is widely practiced to plate a copper, tin or brass that is softer than a high carbon steel wire material in order to meet the precise dimensional tolerances for use purposes and to ensure freshness.

A method of forming a semiconductor wafer by cutting a hard material such as a silicon block using a saw wire is as follows. A series of saw wire rows are wound around a plurality of rollers having a plurality of grooves at a predetermined pitch, and then the series of saw wire rows are run. The silicon block to be cut is pressed with a predetermined force in this series of saw wire rows. At the same time, a polishing liquid is flowed between the saw wire row and the silicon block to cut the silicon block by the grinding action of the abrasive grains, thereby producing a wafer.

A factor that determines the yield of cut tissues using saw wires is kerfloss, which represents the width (cw) of the cutting grooves generated when the saw wires dig into the cut tissues (si) such as silicon ingots. Cyprus and yield are inversely proportional.

In order to minimize the cuff, the wire diameter of the saw wire must be thinned or thinned. To this end, an ultra high strength steel wire having high cutting strength and high toughness is required. Recently, in order to reduce the loss of a carrier such as a silicon ingot and increase the cutting speed, a method of manufacturing a thin wire saw wire having a wire diameter of 0.08 mm or less is required.

In general, the production method of the saw wire is first wire-drawn by heat treatment of carbon steel wire rods, followed by heat-treatment after forming a plating layer of copper, tin, or brass on the outer circumference of the high-strength wire having a wire diameter of 1.0 to 1.5 mm. Through the process of obtaining a saw wire of 0.05 ~ 0.28mm wire diameter. In order to maintain the cutting surface quality of the cut body when manufacturing the saw wire such as wire diameter, deviation, straight line, helix (helix), and the like is precisely managed. Among these, the diameter of the wire diameter and the deviation of the diameter are the main characteristics, and in order to precisely produce them, the material of the final die tip is mainly used as diamond. .

Embodiments of the present invention by the micro-electropolishing treatment of the coating layer after the final wet drawing step, to reduce the bending deviation of the wire surface to prevent disconnection during cutting and to improve the quality characteristics of the cut body and at the same time improve the yield of the saw wire It is to provide a manufacturing method.

Embodiments of the present invention is to provide a sawing wire having a carbon content of 0.67% to 1.5% and tensile strength of 120kg / mm ² to 600kg / mm ² produced by the above manufacturing method.

One aspect of the present invention

Drawing the wire rod of the material with a wire diameter of 2.5 to 3.5 mm, forming a flexible plated layer having a thickness of 3 to 8 μm on the surface of the wire following heat treatment of the drawn wire; It relates to a method of manufacturing a saw wire comprising the step of fine electropolishing of the plating layer to 30% or less so that the surface irregularities difference is 1 μm or less after the step of wet drawing to be in the range of ~ 0.16mm.

Another aspect of the invention

The primary wire drawing step is to wire the material wire rod to a wire in the range of 2.5 to 3.5mm wire diameter, and the second wet wire drawing to the wire diameter of 0.50 ~ 1.50mm following the heat treatment of the primary wire wire and the secondary wet wire drawing of the wire. After the heat treatment, a step of forming a flexible plated layer having a thickness of 3 to 8 μm on the surface of the wire, and a step of third wet drawing the wire having the flexible plated layer formed thereon in a range of 0.02 to 0.08 mm in diameter so that the surface irregularities are less than 1 μm. It relates to a saw wire manufacturing method comprising the step of fine electropolishing to 30% or less.

Another aspect of the present invention relates to a saw wire having a carbon content of 0.67% to 1.5% and a tensile strength of 120kg / mm ² to 600kg / mm ² produced by the above production method.

Saw wire according to the embodiments of the present invention is reduced by less than 1㎛ the bending deviation of the surface of the wire by performing a fine electrolytic polishing after the final wet drawing, the risk of disconnection during cutting, the slurry injected during cutting As the specific surface area is increased, the cut surface quality of the cut body is excellent.

Hereinafter, the embodiment of the present invention will be described in more detail through the manufacturing process diagram shown in FIG. 1.

First, as shown in FIG. 1A, a wire rod 10 is prepared. As the material wire rod, for example, a rod having a diameter of 5.5 mm having a carbon content of 0.8 to 1.1% may be used. Referring to (b) of FIG. 1, the wire rod 10 has a primary cold drawing through a dry continuous drawing machine 12 in which a plurality of drawing dies 11 are arranged so that the wire diameter is 2.5 to 3.5 mm. It is wound on the winder 13 in a reduced state.

Next, as shown in FIG. 1 (c), the process proceeds to a heat treatment and plating process. In the heat treatment and plating process, the wire is subjected to heat treatment while passing through the heating furnace 14 and the lead cooling bath 15, and then, an electrolytic pickling bath. 16, pretreated while passing through the washing tank 17, the alkali washing tank 18 and the washing tank 19, and then a brass plating layer having a thickness of 3 to 8 µm is formed in the brass plating bath 20, and then the washing tank 21 It is wound up on the winder 22 via ().

Subsequently, the brass plated wire passes through a wet continuous drawing machine 24 having a plurality of drawing dies 23 arranged thereon as shown in FIG. The drawing process is drawn to obtain a saw wire having a carbon content of 0.67% to 1.5%, a tensile strength of 120kg / mm ² to 600kg / mm ² and a wire diameter of 0.08 to 0.16mm. At this time, the electrolytic polishing bath 25 may be installed in the wet continuous drawing machine 24, as shown in (d) of FIG.

The electropolishing may be performed using a direct current, a pulse-reverse current, a pulse current, and the like. In this case, the electropolishing may be performed in an acid solution such as sulfuric acid, and an acid solution or wire to be used. According to the wire diameter, the electric current and electrolytic polishing time are adjusted. Such electropolishing is a fine polishing, when fine electropolishing is performed on a plated layer having a thickness of 3 to 8 μm, the plated layer is cut to 30% or less to remove only 0 to 2 μm of the surface of the plated layer, thereby maintaining the difference in surface irregularities to 1 μm or less. Can be. As a result, the difference in the unevenness of the surface of the plating layer before the fine electropolishing may be reduced to 1 to 1.8 μm but 0.5 μm after the fine electropolishing.

In the manufacturing process, the temperature during the heat treatment was set to 500 to 1100 ° C., but the more stable heating temperature for the surface plating layer was about 950 ° C. or less for copper plating, and in the case of brass plating, the difference was somewhat different depending on the zinc content. However, in the case of brass having a zinc content of about 30%, since the plating layer may be damaged at about 870 ° C. or higher, it is preferable to heat it to a temperature below that.

In the case of having a brass plated layer, the lower the zinc content, the higher the heating temperature can be obtained a more uniform heat treatment structure, it is possible to shorten the heating time.

In addition, after the primary drawing process according to (b) of FIG. 1, the heat treatment process and the wet drawing process may be further performed.

First, the wire whose wire diameter is reduced through primary drawing is heat treated (parting) while passing through a heating furnace and a lead cooling tank, and then sequentially passes through an electrolytic pickling tank, a washing tank, a borax bath, and a drying furnace. It undergoes a heat treatment process in which winding is performed on the odor.

Subsequently, the heat-treated wire passes through a wet continuous drawing machine and is wound on a winding machine with a wire diameter of 0.50 to 1.50 mm.

Meanwhile, the reason for limiting the strength of the wire saw wire of the present invention to 120 kg / mm ² to 600 kg / mm ² is to achieve the original purpose of the wire saw wire for cutting and slicing a hard material such as semiconductor, ceramic or cemented carbide. This is to ensure the minimum cutting force required for the purpose. In addition, in order to obtain the required strength as a fine wire wire saw wire, as well as a high processing rate of 98% or more, as well as a method of increasing the strength by adding an alloying element such as chromium or vanadium to raw materials, if necessary. have.

Hereinafter, the configuration and effects of the present invention will be described in more detail with specific examples, but these examples are only intended to more clearly understand the present invention and are not intended to limit the scope of the present invention.

Example 1 Preparation of Saw Wire

The wire rod having a carbon content of 0.80% 5.5 mm in diameter was first fresh so as to have a diameter of 0.95 to 1.30 mm, and then passed through a heating furnace at 1100 ° C. and a molten solder bath at 600 ° C. for a predetermined time, thereby subjecting it to a potting process. Subsequently, the parting wire was pretreated, such as cleaned, and brass plated to a thickness of about 5 μm. Next, the brass plated wire was fresh to 0.12 mm in diameter, and then fine electropolishing was performed in sulfuric acid solution to prepare a saw wire.

Comparative Example 1: Preparation of Saw Wire

The wire rod having a carbon content of 0.80% and 5.5 mm in diameter was first fresh so as to have a diameter of 0.95 to 1.30 mm, and then passed through a heating furnace at 1100 ° C. and a molten solder bath at 600 ° C. for a predetermined time. Subsequently, the parting wire was pretreated, such as cleaned, and brass plated to a thickness of about 5 μm. Next, the brass plated wire was drawn to a diameter of 0.12 mm to prepare a saw wire.

The surface roughness of the cut single body was measured using the contact wire method of the saw wire obtained through the manufacturing method of Example 1 and Comparative Example 1, and the results are shown in Table 1 below.

TABLE 1

2 (a) is a cross-sectional view of the saw wire showing the surface shape of the plating layer according to Example 1, Figure 2 (b) is a cross-sectional view of the saw wire showing the surface shape of the plating layer according to Comparative Example 1, It can be seen that the saw wire has a small surface deviation.

Although the present invention has been described in detail with reference to preferred embodiments of the present invention, it will be apparent to those skilled in the art that the present invention may be variously changed or modified without departing from the spirit and scope of the present invention. Modifications and variations are also to be construed as being included in the scope of protection of the present invention.

The following drawings illustrate one embodiment of the present invention, and together with the detailed description of the present invention serve to assist in understanding the present invention, the present invention should not be construed as limited to the matters set forth in these drawings.

Figure 1 (a) to (d) schematically shows the manufacturing process of the sour wire according to an embodiment of the present invention.

2 (a) is a cross-sectional view of the saw wire according to the first embodiment.

2 (b) is a cross-sectional view of the saw wire according to Comparative Example 1. FIG.

10. Wire rod 11, 23. Fresh dice

12. Dry continuous drawing machine 13, 22. Winding machine

14. Furnace 15. Lead cooling tank

16. Electrolytic pickling tanks 17, 19, 21.

18. Alkali cleaning bath 20. Brass plating bath

24. Wet continuous drawing machine 25. Electrolytic polishing bath

26. Carbon Steel 27. Plating Layer

Claims

Drawing the wire rod of the material with a wire diameter of 2.5 to 3.5 mm, forming a flexible plated layer having a thickness of 3 to 8 μm on the surface of the wire following heat treatment of the drawn wire; A method of manufacturing a saw wire comprising a step of fine electropolishing of the plating layer to 30% or less so that the surface irregularities are less than 1 μm after wet drawing to have a range of ˜0.16 mm.

The primary wire drawing step is to wire the material wire rod to a wire in the range of 2.5 to 3.5mm wire diameter, and the second wet wire drawing to the wire diameter of 0.50 ~ 1.50mm following the heat treatment of the primary wire wire and the secondary wet wire drawing of the wire. After the heat treatment, forming a flexible plating layer having a thickness of 3 to 8 μm on the surface of the wire, and performing a third wet drawing of the wire on which the flexible plating layer is formed to have a wire diameter of 0.02 to 0.08 mm. Saw wire manufacturing method comprising the step of fine electropolishing to 30% or less.

The method according to claim 1 or 2, wherein the heating temperature of the heat treatment step is 500 to 1100 ℃ characterized in that the saw wire manufacturing method.

The saw wire manufacturing method according to claim 1 or 2, wherein the thickness of the flexible plating layer is 3 to 8 µm.

A carbon wire having a content of 0.67% to 1.5%, a tensile strength of 120kg / mm ² to 600kg / mm ² , characterized in that it is manufactured by the manufacturing method of claim 1 or 2.