KR20200102568A - Ingot cutting equipment using multi-wire and electric discharge machining and method for cutting the same - Google Patents

Abstract

Disclosed are an ingot cutting apparatus using multiple wires and electric discharge machining and an ingot cutting method. According to the present invention, the multiple wires having abrasive grains and the electric discharge machining are used to solve a problem of metal contamination of an ingot, and productivity is maximized as cutting technology is applied to fit soft or rigid materials. The ingot cutting apparatus according to the present invention comprises: the multiple wires conveyed in the vertical direction of the ingot and including the abrasive grains on the outer peripheral surface; an electrode connected to the ingot and the multiple wires; and a power supply unit supplying power to the electrode so that arc discharge occurs between the ingot and the multiple wires. The multiple wires are not in contact with the surface of the ingot and generate discharge between the abrasive grain surface and the ingot surface and wire discharge between the wire surface and the ingot surface, thereby cutting the ingot.

Description

Ingot cutting device and ingot cutting method using multi-wire and electric discharge machining {INGOT CUTTING EQUIPMENT USING MULTI-WIRE AND ELECTRIC DISCHARGE MACHINING AND METHOD FOR CUTTING THE SAME}

The present invention relates to an ingot cutting technique using mechanical cutting of multiple wires having abrasive grains and thermal cutting of electric discharge machining.

In a variety of material fields including silicon for solar cells, cutting technology into substrates of ingots or blocks is an important technology for determining the characteristics of a substrate.

Mainly, a method of mechanical cutting of an ingot or block using a wire or diamond wheel is used. Such a mechanical cutting method basically generates various mechanical defects on the surface of the final substrate, which is an object to be cut, based on abrasion and crushing between the object to be cut (silicon, sapphire, compound semiconductor, etc.) and the object to be cut (diamond, etc.). In addition, the mechanical cutting method easily causes mechanical damage to the object to be cut during the cutting process. Therefore, expensive equipment and processes are required to prevent this problem.

In particular, since ductile materials such as thermoelectric semiconductors undergo severe deformation during mechanical cutting, there is a demand for a new cutting technology.

Recently, a new method of cutting technology has been developed rather than such a mechanical cutting method. For example, technologies for applying discharge processing used in metals to semiconductors and ceramics are being developed. Among these, there is discharge processing by pulse type DC current.

Discharge processing using a metal wire is a method in which an arc discharge occurs between the ingot and the metal wire by applying a voltage in the form of a DC pulse to the ingot transfer unit and the metal wire, and cutting is performed by raising and lowering the ingot.

However, the existing electric discharge technology using a metal wire causes serious metal impurities contamination on the object to be cut, and has a limitation in productivity because it is a single wire method using only one wire.

Republic of Korea Patent Publication 10-2016-0053825 (published on May 13, 2016)

An object of the present invention is to provide an ingot cutting technology that solves the metal contamination problem of the ingot by using multiple wires having abrasive grains.

It is also an object of the present invention to provide a rigid ingot cutting technology by a mixing method of mechanical cutting of multiple wires and thermal cutting of electric discharge machining.

It is also an object of the present invention to provide a technology for cutting flexible materials such as compound semiconductors by non-contact and electric discharge processing of multi-wires.

In addition, an object of the present invention is to provide an ingot cutting technology capable of minimizing cutting loss, winding multiple wires, and improving productivity by using a wire having a diameter of 100 μm or less.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention that are not mentioned can be understood by the following description, and will be more clearly understood by examples of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by the means shown in the claims and combinations thereof.

The present invention is conveyed in the vertical direction of the ingot, multiple wires including abrasive grains on the outer peripheral surface; An electrode connected to the ingot and multiple wires; And a power supply for supplying power to the electrode so that arc discharge is made between the ingot and the multiple wires, wherein the multiple wires are non-contact with the ingot surface to generate a discharge between the abrasive surface and the ingot surface, It provides an ingot cutting device for cutting the ingot by generating a wire discharge between the wire surface and the ingot surface.

In addition, the present invention is transported in the vertical direction of the ingot, multiple wires including abrasive grains on the outer peripheral surface; An electrode connected to the ingot and multiple wires; And a power supply for supplying power to the electrode so that arc discharge is made between the ingot and the multiple wires, wherein the multiple wires are in contact with the ingot surface, mechanically cutting the ingot by the abrasive grains, and the wire surface It provides an ingot cutting device for cutting the ingot by generating a wire discharge between the surface of the ingot and the ingot.

In addition, the present invention comprises the steps of (a) disposing multiple wires including abrasive grains on the ingot on the outer circumferential surface; (b) connecting an electrode between the ingot and multiple wires, and supplying power to the electrode; And (c) cutting the ingot by transferring multiple wires in the vertical direction of the ingot; and, in step (c), the multiple wires are not in contact with the ingot surface, so that a discharge is generated between the abrasive surface and the ingot surface. And a wire discharge is generated between the wire surface and the ingot surface to provide an ingot cutting method in which cutting is performed.

In addition, the present invention comprises the steps of (a) disposing multiple wires including abrasive grains on the ingot on the outer circumferential surface; (b) connecting an electrode between the ingot and multiple wires, and supplying power to the electrode; And (c) cutting the ingot by transferring multiple wires in the vertical direction of the ingot; including, in step (c), the multiple wires are brought into contact with the ingot surface to perform mechanical cutting by the abrasive grains, It provides an ingot cutting method in which cutting is performed by generating a wire discharge between the wire surface and the ingot surface.

The ingot cutting technology according to the present invention has the effect of solving the problem of metal contamination of the ingot by using multiple wires having abrasive grains.

In addition, the ingot cutting technology according to the present invention has an effect of maximizing productivity by applying the cutting technology to fit a rigid material or a soft material.

In addition, the ingot cutting technology according to the present invention can minimize cutting loss by using a wire having a diameter of 100 μm or less. Accordingly, the flexibility of the wire is increased so that the winding of multiple wires is possible, and productivity can be improved through the multiple wires.

In addition to the above-described effects, specific effects of the present invention will be described together while describing specific details for carrying out the present invention.

1 is a cross-sectional view of a non-contact cutting for cutting a soft material.
2 is a cross-sectional view of a contact cutting for cutting a rigid material.
3 and 4 are perspective views showing an ingot cutting apparatus using multiple wires and electric discharge machining according to the present invention.
Figure 5 is a cut photograph of a silicon ingot using a multi-diamond wire of the present invention.
6 is a photograph of a substrate cut with a multi-diamond wire of the present invention.
7 is a graph showing a change in discharge depth according to discharge conditions of substrates cut with a multi-diamond wire according to the present invention.
8 is a SEM photograph of a multi-wire formed on the outer peripheral surface of the diamond according to the present invention.
9 is a SEM photograph of a conventional wire.

The above-described objects, features, and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, one of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar elements.

Hereinafter, it means that an arbitrary component is disposed on the "top (or lower)" of the component or the "top (or lower)" of the component, the arbitrary component is arranged in contact with the top (or bottom) of the component. In addition, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

In addition, when a component is described as being "connected", "coupled" or "connected" to another component, the components may be directly connected or connected to each other, but other components are "interposed" between each component. It is to be understood that "or, each component may be "connected", "coupled" or "connected" through other components.

Hereinafter, an ingot cutting apparatus and an ingot cutting method using multiple wires and electric discharge machining according to some embodiments of the present invention will be described.

The present invention provides an ingot cutting device comprising a multi-wire for cutting the ingot, an electrode connected to the ingot and the multi-wire, and a power supply for supplying power to the electrode so that arc discharge is made between the ingot and the multi-wire. I want to.

In the present invention, the ingot, which is an object to be cut, may be an ingot including silicon, sapphire, or a compound semiconductor, but is not limited thereto.

The multiple wires 30 are transferred in the vertical direction of the ingot. Specifically, the multi-wire 30 is multiplely wound around the pair of main rollers 20 to form a wire web, and cuts the ingot as the pair of main rollers 20 are raised and lowered.

The pair of main rollers 20 are located on the ingot, but are preferably located on both sides of the ingot. Each of the main rollers has grooves that determine the distance between the wires. The spacing of the grooves may determine the thickness of the wafer. In the present invention, a wire web is formed by winding multiple wires on each main roller. To this end, it is preferable that a plurality of grooves are formed in the wire.

The multi-wire 30 includes the conductive abrasive grains 32 on the outer circumferential surface in the longitudinal direction, thereby providing an effect of solving the metal contamination problem of the cut object.

The material of the wire may be a material including at least one of steel wire, nickel, and nichrome wire. The average diameter of the wire is preferably 100 μm or less, and more preferably 10 to 100 μm. Here, the average diameter of the multiple wires means the average diameter of the core steel wire, that is, the inner steel wire.

When the average diameter of the wire satisfies 100 μm or less, it becomes thinner than 300 μm in thickness of the existing wire, thereby minimizing the cutting loss of the ingot. In addition, it is possible to wind multiple wires while increasing the flexibility of the wire, thereby improving the productivity of the cutting process.

The abrasive grain 32 is preferably a conductive abrasive grain. For example, the abrasive grains are BaB ₆ , CeB ₆ , Co ₂ B, CoB, FeB, GdB ₄ , GdB ₆ , LaB ₄ , LaB ₆ , Mo ₂ B, MoB, MoB ₂ , Mo ₂ B ₅ , Nb ₃ B ₂ , NbB, Nb ₃ B ₄ , NbB ₂ , NdB ₄ , NdB ₆ , PrB ₄ , PrB ₆ , SrB ₆ , TaB, TaB ₂ , TiB, TiB ₂ , VB, VB ₂ , W ₂ B ₅ , YB ₄ , YB ₆ , YB _12, and a conductive boride ceramic containing at least one of ZrB ₂ , MoC, Mo ₂ C, Nb ₂ C, NbC, Ta ₂ C, TaC, TiC, V ₂ C, VC, WC, W ₂ C, and a conductive nitride ceramic containing at least one of ZrC, Mo ₂ N, Nb ₂ N, NbN, ScN, Ta ₂ N, TiN, and a conductive nitride ceramic containing at least one of ZrN, CoSi ₂ , Mo ₃ Si, Mo ₅ Si ₃ , MoSi ₂ , NbSi ₂ , Ni ₂ Si, Ta ₂ Si, TaSi ₂ , TiSi, TiSi ₂ , V ₅ Si ₃ , VSi ₂ , W ₃ Si, WSi ₂ , ZrSi and ZrSi _It may be a conductive silicide ceramic containing at least one of _two . Preferably, the abrasive grains include at least one of diamond coated with a conductive material and silicon carbide (SiC). The abrasive grain may be formed of a material having excellent hardness and machinability. In the present invention, it is preferable to improve the discharge effect by using diamond abrasive grains coated with a conductive material such as nickel.

The average size of the abrasive grains 32 is preferably 50 μm or less, and more preferably 10 to 30 μm. By satisfying the average size of the abrasive grains of 50 μm or less, cutting efficiency by multiple wires and discharge due to the abrasive grains can be further improved. In addition, there is an effect of minimizing the cutting loss of the ingot. In addition, it is possible to wind multiple wires while increasing the flexibility of the wire, thereby improving the productivity of the cutting process.

The ingot cutting apparatus of the present invention has an effect of maximizing productivity by applying a cutting technique to fit a rigid material or a soft material.

1 is a cross-sectional view of a non-contact cutting for cutting a soft material. As shown in FIG. 1, by applying a non-contact cutting process to the surface of a soft material, cutting by electric discharge machining can be performed. In this process, multiple wires generate a discharge between the abrasive grain surface and the material surface, and simultaneously generate a wire discharge between the wire surface and the material surface to be cut.

Therefore, for a soft material, the ingot can be cut by non-contact cutting and electric discharge machining of multiple wires.

2 is a cross-sectional view of a contact cutting for cutting a rigid material. As shown in FIG. 2, by applying a contact cutting process to the surface of a rigid material, cutting can be performed in a mixed method of mechanical cutting and electric discharge machining of multiple wires. In this process, the multi-wire is cut by mechanically cutting the ingot by abrasive grains, and by generating a wire discharge between the wire surface and the ingot surface.

The ingot cutting apparatus of the present invention will be described in more detail as follows.

3 and 4 are perspective views showing an ingot cutting apparatus using multiple wires and electric discharge machining according to the present invention.

Referring to FIG. 3, the ingot cutting apparatus using multiple wires and electric discharge machining includes a water tank 10, a pair of main rollers 20, a multiple wire 30, an electrode roller 40, and a power supply unit 50. Include.

In the water tank 10, an ingot, which is an object to be cut, is placed. A jig is attached to the lower surface of the ingot, and a conductive adhesive layer is attached between the ingot and the jig. The conductive adhesive layer may be formed from an adhesive composition including a conductive polymer, an adhesive monomer, etc., but is not limited thereto.

The ionized purified water accommodated in the water tank 10 is a dielectric material capable of electrolysis, and its concentration and purity are maintained by an electrical conductivity measurement sensor unit connected to the water tank 10. In order to increase the cutting efficiency of the ingot, it is preferable to maintain the height of the ionized purified water so that the ingot is completely contained.

The pair of main rollers 20 cut the ingot as it rises and descends in the vertical direction of the ingot.

The electrodes connected to the ingot and the multiple wires indicate a first electrode and a second electrode. The electrode roller 40 on which the wire is wound is in contact with the surface of the multi-wire 30. When power is supplied to the electrode roller 40, a first electrode is formed. The second electrode is connected to the ingot.

The pair of main rollers 20 and electrode rollers 40 are formed by wires, an inlet roller 41, a first motor 42, a guide roller 43, an outlet roller 45, and a second motor 46. ).

The inlet roller 41 is a roller on which a wire before being discharged is wound. A first motor 42 is located at the rear end of the inlet roller 41. The first motor 42 adjusts the tension of the wire wound around the inlet roller 41. In addition, the first motor 42 prevents vibration of the wire by maintaining a constant tension of the wire, and prevents damage to the wafer. In order to prevent separation of the wire transferred from the inlet roller 41, a first guide rod 47a is further installed.

A first guide roller 43a is installed to transfer the wire transferred along the first guide rod 47a to the electrode roller 40. The guide roller holds the minimum vibration and helps the wire to be transferred smoothly.

In addition, a second guide roller 43b is installed to guide the wires transferred from the electrode roller 40 to be recovered. In order to prevent separation of the wire conveyed from the second guide roller 43b, a second guide rod 47b is further installed. An outlet roller 45 is installed to recover the wire conveyed along the second guide rod 47b. A second motor 46 is located at the rear end of the exit roller 45. The second motor 46 adjusts the moving speed of the wire wound around the exit roller 45.

Like the first guide roller 43a and the second guide roller 43b, a plurality of guide rollers 43 may be installed at the upper ends of both sides based on the position of the electrode roller 40, but are limited thereto. no.

The power supply unit 50 supplies power to the first electrode and the second electrode so that arc discharge is performed between the ingot and the multiple wires 30. The (+) electrode may be connected to the ingot, and the (-) electrode may be connected to the multiple wires 30.

Ingot cutting method using multiple wires and electric discharge machining according to the present invention is as follows.

First, the inside of the water tank 10 is provided with purified ionized water and an ingot immersed in the purified ionized water. In addition, multiple wires 30 that are wound multiple times are provided on a pair of main rollers 20 spaced apart on the ingot. It is preferable that the multiple wires 30 include abrasive grains 32 formed on the outer circumferential surface. Details on this are as described above.

The electrode roller 40 is brought into contact with the surface of the multiple wires 30. Connect an electrode to the ingot.

Subsequently, power is supplied to the electrode so that arc discharge is performed between the ingot and the multiple wires 230. The (+) electrode may be connected to the ingot, and the (-) electrode may be connected to the multiple wires 30.

Subsequently, the ingot is cut by transferring the multiple wires 30 that are multiplely wound around the pair of main rollers 20 in the vertical direction of the ingot.

At this time, when the ingot is ductile, multiple wires are not in contact with the surface of the ingot, thereby cutting. A discharge is generated between the abrasive grain surface and the ingot surface, and a wire discharge is generated between the wire surface and the ingot surface to perform cutting.

When the ingot is rigid, multiple wires come into contact with the surface of the ingot to make cutting. Mechanical cutting is performed by the abrasive grains, and a wire discharge is generated between the wire surface and the ingot surface to perform the cutting.

As such, the ingot cutting technique of the present invention has an effect of minimizing the metal contamination problem of the cut object by using multiple wires including conductive abrasive grains instead of metal wires. In addition, the ingot cutting technology can maximize the productivity of wafers per ingot by applying the cutting technology according to the soft or rigid material. In addition, it is possible to increase the flexibility of the wire by making the diameter of the wire less than 100㎛, minimizing cutting loss and cutting multiple wires.

A detailed embodiment of the ingot cutting device and the ingot cutting method using multiple wires and electric discharge machining will be described as follows.

Figure 5 is a cut photograph of a silicon ingot using a multi-diamond wire of the present invention. 6 is a photograph of a substrate cut with a multi-diamond wire of the present invention. The diamond multi-wire of FIGS. 5 and 6 was a steel wire having a diameter of 60 μm and a diamond having an average size of 20 μm.

5 and 6, it is shown that a wafer having a uniform thickness can be produced by cutting an ingot, and multiple wires can be cut without being damaged in the cutting process.

7 is a graph showing a change in discharge depth according to discharge conditions of substrates cut with a multi-diamond wire according to the present invention.

Referring to FIG. 7, under the condition that the voltage of the arc discharge pulse is 150 to 350 V, when the holding time of the arc discharge pulse is 2.5 to 7.5 μs, the cutting depth by the arc discharge is 25 to 200 μm. In particular, as the voltage increases, the cutting depth tends to increase. In addition, if the pulse holding time is lengthened, a relatively high current is generated, thereby increasing the cutting depth. In other words, the pulse voltage and pulse duration are the most important process variables that determine the cutting depth.

[Table 1] shows the cutting results of the silicon ingot according to the discharge conditions.

Using the cutting device shown in Fig. 2, a silicon ingot (30 mm x 30 mm x 30 mm) was cut with a steel wire (multi-wire) with diamonds formed on the outer circumferential surface. The average diameter of the steel wire is 60 μm, and the average size of diamond is 20 μm.

If the silicon ingot is cut without cutting loss, it is marked as "Slicing (good or best)", if the cutting loss is less than 10%, it is marked as "Slicing", and if no discharge occurs and the cutting loss is more than 10%, it is marked as "No discharge.

[Table 1]

Referring to Table 1, when the voltage is 100~350V, the current is 1~10A, the pulse duration of arc discharge is 2.5~15μs, and the resistance is 100Ω or less, mechanical cutting and electric discharge machining are performed. In particular, it can be seen that cutting was efficiently performed without breakage when the voltage was 150 to 200 V and the pulse holding time of the arc discharge was 2.5 to 9 μs.

8 is an SEM photograph of a multi-wire (steel wire) formed on the outer peripheral surface of the diamond according to the present invention, and FIG. 9 is a SEM photograph of a conventional wire (steel wire). 8 and 9, the average diameter of the steel wire is 100 μm. The average size of the diamond is 10 μm.

Referring to FIG. 8, it can be seen that a diamond of a uniform size is embedded on the surface of the wire. Such a diamond wire can solve the problem of metal contamination of the cut object. In addition, by using the contact cutting of the diamond wire or the non-contact cutting of the diamond wire, a cutting method suitable for a soft material or a rigid material may be applied.

As described above, the ingot cutting technology using multi-wire and electric discharge processing including abrasive grains of the present invention is highly applicable to flexible materials such as thermoelectric semiconductors as well as solar cells.

As described above with reference to the drawings illustrated for the present invention, the present invention is not limited by the embodiments and drawings disclosed in the present specification, and various by a person skilled in the art within the scope of the technical idea of the present invention. It is obvious that transformation can be made. In addition, even if not explicitly described and described the effects of the configuration of the present invention while describing the embodiments of the present invention, it is natural that the predictable effects of the configuration should also be recognized.

10: water tank
20: a pair of main rollers
30: multiple wire
32: abrasive
40: electrode roller
41: inlet roller
42: first motor
43: guide roller
43a: first guide roller
43b: second guide roller
45: exit roller
46: second motor
47a: first guide rod
47b: second guide rod
50: power supply

Claims (14)

Multiple wires conveyed in the vertical direction of the ingot and including abrasive grains on the outer circumferential surface;
An electrode connected to the ingot and multiple wires; And
Includes; a power supply for supplying power to the electrode so that the arc discharge is made between the ingot and the multiple wires,
The multi-wire is non-contact to the ingot surface, generates a discharge between the abrasive grain surface and the ingot surface, and generates a wire discharge between the wire surface and the ingot surface to cut the ingot.
Multiple wires conveyed in the vertical direction of the ingot and including abrasive grains on the outer circumferential surface;
An electrode connected to the ingot and multiple wires; And
Includes; a power supply for supplying power to the electrode so that the arc discharge is made between the ingot and the multiple wires,
The multi-wire is in contact with the ingot surface, mechanically cuts the ingot by the abrasive grains, and generates a wire discharge between the wire surface and the ingot surface to cut the ingot.
The method according to claim 1 or 2,
The multi-wire ingot cutting device comprising at least one of a steel wire, nickel, and nichrome wire.
The method according to claim 1 or 2,
The abrasive grains are BaB ₆ , CeB ₆ , Co ₂ B, CoB, FeB, GdB ₄ , GdB ₆ , LaB ₄ , LaB ₆ , Mo ₂ B, MoB, MoB ₂ , Mo ₂ B ₅ , Nb ₃ B ₂ , NbB, Nb ₃ B ₄ , NbB ₂ , NdB ₄ , NdB ₆ , PrB ₄ , PrB ₆ , SrB ₆ , TaB, TaB ₂ , TiB, TiB ₂ , VB, VB ₂ , W ₂ B ₅ , YB ₄ , YB ₆ , YB ₁₂ and a conductive boride ceramic containing at least one of ZrB ₂ , or
MoC, Mo ₂ C, Nb ₂ C, NbC, Ta ₂ C, TaC, TiC, V ₂ C, VC, WC, W ₂ C, and a conductive carbide ceramic containing at least one of ZrC, or
Mo ₂ N, Nb ₂ N, NbN, ScN, Ta ₂ N, TiN, or a conductive nitride ceramic containing at least one of ZrN,
CoSi ₂ , Mo ₃ Si, Mo ₅ Si ₃ , MoSi ₂ , NbSi ₂ , Ni ₂ Si, Ta ₂ Si, TaSi ₂ , TiSi, TiSi ₂ , V ₅ Si ₃ , VSi ₂ , W ₃ Si, WSi ₂ , ZrSi And a conductive silicide ceramic comprising at least one of ZrSi ₂ .
The method of claim 1,
The abrasive grain is an ingot cutting device including at least one of diamond coated with a conductive material and silicon carbide (SiC).
The method according to claim 1 or 2,
The average diameter of the multi-wire is 100㎛ or less ingot cutting device.
The method of claim 1,
The average size of the abrasive grain is 50㎛ or less ingot cutting device.
(a) disposing multiple wires including abrasive grains on the ingot on the outer circumferential surface;
(b) connecting an electrode between the ingot and multiple wires, and supplying power to the electrode; And
(c) cutting the ingot by transferring multiple wires in the vertical direction of the ingot; including,
In the step (c), the multiple wires are not in contact with the ingot surface to generate a discharge between the abrasive grain surface and the ingot surface, a wire discharge is generated between the wire surface and the ingot surface, cutting ingot cutting method is performed.
(a) disposing multiple wires including abrasive grains on the ingot on the outer circumferential surface;
(b) connecting an electrode between the ingot and multiple wires, and supplying power to the electrode; And
(c) cutting the ingot by transferring multiple wires in the vertical direction of the ingot; including,
In the step (c), a mechanical cutting is performed by the abrasive grains by contacting multiple wires with the ingot surface, and the cutting is performed by generating a wire discharge between the wire surface and the ingot surface.
The method according to claim 8 or 9,
The multi-wire ingot cutting method comprising at least one of a steel wire, nickel, and nichrome wire.
The method according to claim 8 or 9,
The abrasive grains are BaB ₆ , CeB ₆ , Co ₂ B, CoB, FeB, GdB ₄ , GdB ₆ , LaB ₄ , LaB ₆ , Mo ₂ B, MoB, MoB ₂ , Mo ₂ B ₅ , Nb ₃ B ₂ , NbB, Nb ₃ B ₄ , NbB ₂ , NdB ₄ , NdB ₆ , PrB ₄ , PrB ₆ , SrB ₆ , TaB, TaB ₂ , TiB, TiB ₂ , VB, VB ₂ , W ₂ B ₅ , YB ₄ , YB ₆ , YB ₁₂ and a conductive boride ceramic containing at least one of ZrB ₂ , or
MoC, Mo ₂ C, Nb ₂ C, NbC, Ta ₂ C, TaC, TiC, V ₂ C, VC, WC, W ₂ C, and a conductive carbide ceramic containing at least one of ZrC, or
Mo ₂ N, Nb ₂ N, NbN, ScN, Ta ₂ N, TiN, or a conductive nitride ceramic containing at least one of ZrN,
CoSi ₂ , Mo ₃ Si, Mo ₅ Si ₃ , MoSi ₂ , NbSi ₂ , Ni ₂ Si, Ta ₂ Si, TaSi ₂ , TiSi, TiSi ₂ , V ₅ Si ₃ , VSi ₂ , W ₃ Si, WSi ₂ , ZrSi And a conductive silicide ceramic comprising one or more of ZrSi ₂ .
The method according to claim 8 or 9,
The abrasive grains are diamond coated with a conductive material, and ingot cutting method comprising at least one of silicon carbide (SiC).
The method according to claim 8 or 9,
The average diameter of the multi-wire is 100㎛ or less ingot cutting method.
The method according to claim 8 or 9,
The average size of the abrasive grain is 50㎛ or less ingot cutting method.

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