WO2014109149A1

WO2014109149A1 - Resin-bond wire saw

Info

Publication number: WO2014109149A1
Application number: PCT/JP2013/082639
Authority: WO
Inventors: 正彦池内; Tadashi Endo (遠藤忠)
Original assignee: 株式会社Tkx
Priority date: 2013-01-10
Filing date: 2013-12-04
Publication date: 2014-07-17
Also published as: KR101594747B1; CN104918752B; SG11201504210SA; TW201433391A; KR20150102946A; JP5792208B2; CN104918752A; JP2014133288A; TWI519366B; MY168372A

Abstract

[Problem] To provide a resin-bond wire saw having good cutting performance and a long lifespan. [Solution] A resin-bond wire saw in which abrasive grains are fixed to the surface of the wire by a resin bond containing a novolac-type phenol resin, a resol-type phenol resin, and an amine-based silane coupling agent. The resin bond shows a plurality of peaks at intervals of 208 (m/z) that represent fragments in positive ions in MALDI-TOF-MS (mass spectrometry), and a peak that corresponds to a softening point at 175°C to 182°C in TG-DTA (differential thermal analysis).

Description

Resin bond wire saw

The present invention relates to a resin bond wire saw (resin bond wire saw) used for cutting silicon ingots and the like.
saw). A resin bond wire saw is obtained by fixing abrasive grains to a wire with a resin bond (resin adhesive). The wire used for cutting is also referred to as “saw wire”, but in the present specification, it is referred to as “wire saw”.

Conventionally, an inner peripheral blade dicer has been used for cutting a silicon ingot. However, as the size of the silicon ingot increases, the inner peripheral edge dicer causes problems such as a decrease in productivity, generation of a work-affected layer, a decrease in dimensional accuracy, and an increase in the size of the apparatus. Therefore, in recent years, cutting using a wire saw has been performed. Cutting using a wire saw is easy to cope with the increase in size of the ingot. A plurality of wafers can be obtained by one cutting.

There are two types of wire saws: loose abrasive wire saws and fixed abrasive wire saws. The loose abrasive wire saw uses a wire such as a piano wire and an abrasive liquid in which abrasive grains are dispersed in a liquid. The abrasive is diamond fine particles or silicon carbide fine particles. The free abrasive wire saw cuts by moving the wire while dripping the abrasive liquid onto the cutting part (Patent Document 1: Japanese Patent Application Laid-Open No. 2008-103690). The loose abrasive wire saw cuts the ingot with abrasive grains sandwiched between the wire and the ingot.

In the free abrasive wire saw, the viscosity of the abrasive liquid varies depending on the temperature, so that the wafer thickness varies or the flatness of the wafer deteriorates. Moreover, in the case of a loose abrasive wire saw, it is difficult to use a thin wire because the wire is also worn by the abrasive grains. Further, in the case of a loose abrasive wire saw, there is a possibility that a thick work-affected layer is formed on the wafer surface.

In order to solve the problem of loose abrasive wire saws, fixed abrasive wire saws in which abrasive grains are fixed on the wire surface have been proposed. As means for fixing the abrasive grains to the wire surface, there are an electrodeposition method, a brazing method, and a resin bond method.

The electrodeposition method is one in which abrasive grains are fixed to the wire surface by nickel plating or the like (Patent Document 2: Japanese Patent Publication No. 4-4105, Patent Document 3: Japanese Patent Application Laid-Open No. 2003-334863). In the electrodeposition method, abrasive grains are embedded in a nickel film while nickel is deposited on the wire surface in a nickel plating solution. The electrodeposition method has excellent ingot cutting performance because the abrasive grains are firmly fixed.

In the electrodeposition method, abrasive grains are buried deeply in the plating layer and fixed. Since the electrodeposition method requires a thick plating film, the productivity is poor and the cost is high. Furthermore, since the wire is thickened by the nickel plating layer, the wire is liable to cause fatigue fracture.

In the brazing method, a brazing material layer is formed on the wire surface, abrasive grains are embedded in the melted brazing material layer, and the brazing material layer is solidified to fix the abrasive grains (Patent Document 4: Japanese Patent Laid-Open No. 2006-123024). When the melting point of the brazing material is high, the wire is overheated when the brazing material layer is melted, and the strength of the wire is lowered. For this reason, it is difficult to select a wire material by the brazing method. It is difficult to use a piano wire or a hard steel wire whose strength decreases at a low temperature, and a stainless steel wire or a tungsten wire is used. On the contrary, when the melting point of the brazing material is low, the brazing material is melted by frictional heat at the time of cutting the ingot, and the abrasive grains may fall off.

In the resin bond method, a mixture of a liquid resin bond (resin adhesive) and abrasive grains is coated on the wire surface and heated in a baking furnace (Patent Document 4: JP-A 2006-123024). Abrasive grains are fixed by a resin bond cured by heating (Patent Document 5: Japanese Patent Laid-Open No. 2000-26352, Patent Document 6: Japanese Patent Laid-Open No. 2000-271872, Patent Document 7: Republished Patent WO 98/35784). A hot-air drying furnace is known as a baking furnace (Patent Document 8: Japanese Patent Laid-Open No. 09-35556, Patent Document 9: Japanese Patent Laid-Open No. 2010-267533).

レ The resin bond method is suitable for manufacturing long and inexpensive wire saws. Furthermore, since the vibration of the wire saw generated during the cutting of the ingot is absorbed by the flexible resin bond, the wire saw can be stably driven at a high speed. Moreover, a thin wafer can be obtained. On the other hand, since the resin bond wire saw has a low holding power of abrasive grains, the abrasive grains easily fall off during cutting. When a thermosetting resin bond is used, it takes a long time to cure the resin bond, so that it takes time to manufacture the wire saw. When the resin bond is cured at a high temperature, bubbles are generated by volatile components.

JP 2008-103690 A Japanese Examined Patent Publication No. 4-4105 JP 2003-334863 A JP 2006-123024 A Japanese Patent Application Laid-Open No. 2000-263452 Japanese Patent Laid-Open No. 2000-271872 Republished patent WO98 / 35784 JP 09-35556 A JP 2010-267533 A

An object of the present invention is to provide a resin bond wire saw with good cutting performance and long life.

The present inventors use (1) a resin containing a novolak type phenol resin, a resol type phenol resin and an amine silane coupling agent as a resin bond, and (2) by infrared irradiation. It has been found that the object of the present invention can be achieved by curing a resin bond. According to the present invention, it has become possible to efficiently produce a resin bond wire saw having a long life and excellent cutting performance with little abrasive grains falling off.

In the resin bond wire saw of the present invention, the abrasive grains are fixed to the surface of the wire by the resin bond mainly composed of phenol resin. In the resin bond used in the present invention, peaks indicating fragments of 208 (m / z) intervals in the cation are detected by mass spectrometry using the MALDI-TOF-MS method. Further, a peak corresponding to the softening point is detected at 175 ° C. to 182 ° C. by the thermogravimetric / differential thermal analysis (TG-DTA) method. (MALDI: matrix-assisted laser desorption ionization method, TOF-MS: time-of-flight mass spectrometry).

The resin bond used in the present invention contains 100 parts by weight of a novolac type phenol resin, 10 parts by weight to 30 parts by weight of a resole type phenol resin, and 0.1 parts by weight to 5 parts by weight of an amine silane coupling agent.

According to the present invention, a resin bond wire saw with good cutting performance and long life is realized.

Explanatory drawing of the method of infrared heating the paste coated on the wire Lamp energy spectral distribution Cation measurement chart of mass spectrometry by MALDI-TOF-MS method (comparative example) Cation measurement chart for mass spectrometry by MALDI-TOF-MS method (Example 1) Anion measurement chart of mass spectrometry by MALDI-TOF-MS method (comparative example) Example of anion measurement chart of mass spectrometry by MALDI-TOF-MS method (Example 1) Differential thermal analysis chart of Example 1 and Comparative Example

The resin bond wire saw of the present invention fixes abrasive grains to the wire surface by a resin bond containing a novolak type phenol resin, a resole type phenol resin, and an amine silane coupling agent.

The novolac type phenol resin is obtained by condensation reaction of phenol compounds such as phenol, cresol and bisphenol A and aldehydes such as formaldehyde under an acidic catalyst. The resol type phenol resin is obtained by condensation reaction of a phenol compound such as phenol, cresol, bisphenol A and an aldehyde such as formaldehyde under a basic catalyst.

The resin bond may further contain a curing agent. The curing agent is preferably contained in an amount of 5 to 20 parts by weight with respect to 100 parts by weight of the novolac type phenol resin.

When the curing agent exceeds 20 parts by weight with respect to 100 parts by weight of the novolak-type phenolic resin, the gas generated by the decomposition of the curing agent may cause swelling and cracking. When the curing agent is less than 5 parts by weight with respect to 100 parts by weight of the novolak-type phenol resin and the amount of the resol-type phenol resin is small, the novolak resin may be insufficiently cured. In this case, the amount of the resol type phenol resin may be increased, but it is more preferable to increase the amount of the curing agent in the range of 5 to 20 parts by weight. When the curing agent is added in the above proportion, the curing time of the paste described later is shortened.

Examples of the curing agent include hexamethylenetetramine, methylol melamine, and methylol urea. Of these, hexamethylenetetramine is preferred because of its short curing time.

The resin bond may further contain 5 to 15 parts by weight of a phenol compound such as phenol, cresol, or bisphenol A. Moreover, 1 weight part or less of aldehydes, such as formaldehyde, may be included. Furthermore, if it is a small amount, it may contain a basic catalyst or moisture.

Since the resin bond contains 10 to 30 parts by weight of the resole phenolic resin with respect to 100 parts by weight of the novolak type phenolic resin, a dense three-dimensional network structure is formed by crosslinking. As a result, the resin bond and the abrasive grains are firmly bonded. When the resol type phenol resin exceeds 30 parts by weight with respect to 100 parts by weight of the novolak type phenol resin, the viscosity of the paste becomes too low and it becomes difficult to coat the wire with the paste. When the resol type phenol resin is less than 10 parts by weight with respect to 100 parts by weight of the novolak type phenol resin, the curing rate of the resin bond becomes slow. For this reason, it becomes difficult to harden the paste in a short time, and the production speed of the resin bond wire saw becomes slow.

When 0.1 to 5 parts by weight of an amine-based silane coupling agent is added to 100 parts by weight of a novolak-type phenolic resin, the adhesive strength between the resin bond and the wire increases. If the amine-based silane coupling agent is less than 0.1 parts by weight based on 100 parts by weight of the novolak-type phenol resin, an increase in adhesive strength cannot be expected. If the amine-based silane coupling agent exceeds 5 parts by weight with respect to 100 parts by weight of the novolac type phenol resin, the curing of the novolac type phenol resin is adversely affected.

Examples of amine-based silane coupling agents include 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane. Examples include 3-aminopropyltriethoxysilane.

The resin bond contains 100 parts by weight of a novolak type phenol resin, 10 parts by weight to 30 parts by weight of a resole type phenol resin, and 0.1 part by weight to 5 parts by weight of an amine-based silane coupling agent. By using such a resin bond, it is possible to obtain a resin bond wire saw having good cutting performance and a long life.

The manufacturing method for manufacturing the resin bond wire saw of the present invention includes (a) a step of preparing a paste (including a resin bond, a solvent, abrasive grains, and a filler), (b) a step of preparing a wire, and (c) a paste. A step of coating the surface of the wire; and (d) a step of curing the coated paste by infrared heating.

The resin bond is quickly dehydrated and condensed by infrared heating, and a dense three-dimensional crosslinked structure is formed.

ペースト Paste the coated wire with the dispenser method or floating die method. The coating amount of the paste is set so that the concentration of abrasive grains is 50 to 120. The degree of concentration of abrasive grains is the ratio of the area of abrasive grains to the projected area of the wire surface. In the present specification, the degree of concentration is set to 100 when the projected area of the abrasive grains in the total projected area is 15%. For example, the concentration degree is 200 when the projected area of the abrasive grains in the total projected area is 30%, and the concentrated degree is 50 when the projected area of the abrasive grains in the total projected area is 7.5%.

The viscosity of the paste is 3 Pa · s to 6 Pa · s by adding a solvent to the resin bond. The amount of the solvent is preferably in the range of 100 to 200 parts by weight with respect to 100 parts by weight of the resin bond. The solvent is not particularly limited, but considering the reactivity, orthocresol having a low boiling point is preferable.

The abrasive grains are not particularly limited, but diamond abrasive grains, CBN abrasive grains, alumina abrasive grains, silicon carbide abrasive grains and the like are used.

Since diamond abrasive grains have high thermal conductivity, the temperature of the shaded area of the abrasive grains rises quickly during infrared heating. As a result, the resin bond is uniformly cured, and therefore diamond abrasive grains are preferably used. The size of the abrasive grains is selected according to the purpose or according to the wire diameter, but is preferably several μm to 25 μm in order to reduce the kerf loss (cutting allowance). As the abrasive grains, diamond abrasive grains coated with a metal film such as nickel or titanium are also preferable. However, diamond abrasive grains coated with a copper film are not preferred because the efficiency of the silicon solar cell is reduced by copper atoms. Resin bond wire saws using nickel film-coated diamond abrasive grains have less warpage or saw marks on a cut silicon wafer than electrodeposition wire saws.

It is desirable that the abrasive grains are appropriately dispersed on the wire surface in order to avoid clogging with silicon scraps. The abrasive is preferably blended in an amount of 50 to 120 parts by weight per 100 parts by weight of the resin bond.

Steel wire is preferable as the wire. The wire diameter is not particularly limited, but 0.05 mmφ to 0.3 mmφ is preferable. Steel wires include heat-treated spring steel wires such as high-carbon steel and medium-carbon low alloy steel, hard steel wires, piano wires and stainless steel wires, cold-rolled steel wires and oil-tempered wires such as spring steel wires, low High toughness and high fatigue strength steel wires such as alloy steel, medium alloy steel, high alloy steel, and maraging steel are suitable.

¡Infrared heating while running the wire coated with paste to cure the paste. When heating with hot air using a conventional enamel furnace or the like, thermosetting occurs from the surface of the paste, so water generated by the reaction may be trapped inside the paste and bubbles may be generated. On the other hand, when the paste is heated by infrared rays, near-infrared rays having a wavelength of about 1 μm are efficiently absorbed by water, so that crosslinking polymerization is completed in a short time. When the paste is heated by infrared rays, water evaporates in a short time, so that bubbles are hardly generated in the paste. Infrared rays preferably have a spectrum peak in the near-infrared band with a wavelength of 0.7 μm to 2.5 μm. Near-infrared light having a wavelength of about 1 μm (0.9 μm to 1.3 μm) is particularly preferable because it can suppress bubbles accompanying vaporization of the generated water.

Infrared heating allows the curing reaction to proceed at a higher speed than hot air heating, and a uniform higher order structure is obtained. As a result, a peak indicating 208 (m / z) -spaced fragments in the cation is detected in the cured resin bond by mass spectrometry using the MALDI-TOF-MS method. In addition, a clear peak corresponding to the softening point is detected at 175 ° C. to 182 ° C. by the differential thermal analysis (DTA) method. The peak temperature varies somewhat depending on the temperature rise rate during differential thermal analysis. The peaks in the differential thermal analysis reflect a uniform higher order structure, with peaks showing fragments at 208 (m / z) intervals. The uniform higher order structure increases the hardness of the resin bond and holds the abrasive grains firmly. Thereby, the resin bond wire saw excellent in cutting performance is obtained.

FIG. 1 is an explanatory diagram in which a wire coated with paste is heated by infrared rays. In the method of FIG. 1, a semi-cylindrical concave mirror 2 and a linear infrared heater 4 arranged in the longitudinal direction of the concave mirror 2 are used. The wire 3 coated with the paste is caused to run in the longitudinal direction of the concave mirror 2 (perpendicular to the paper surface). Infrared light from the infrared heater 4 is reflected by the reflecting surface 8 and condensed on a condensing part 6 (heating zone) of about 10 mmφ. A plurality of concave mirrors 2 and infrared heaters 4 may be arranged so as to surround the traveling path of the wire 3.

The length of the condenser 6 is determined by the size and number of the infrared heater 4 and the concave mirror 2. The wire 3 coated with the paste is run and the paste is heated by infrared rays. The length of the light collecting unit 6 is, for example, 400 mm to 1000 mm. In order to lengthen the condensing unit 6, a plurality of infrared heaters 4 may be arranged in series in the traveling direction of the wire 3 (perpendicular to the paper surface).

As the infrared heater 4, an infrared lamp having a peak in the near infrared region is preferable. As an infrared lamp, for example, a short arc xenon lamp (short-arc
xenon lamp) or a lamp in which a tungsten filament is sealed in a quartz glass tube.

It is difficult to measure the temperature of the wire 3 that travels through the light collector 6. Therefore, focusing on the fact that the breaking strength of the wire 3 is reduced by heating, the heating temperature is set so that 95% of the breaking strength before heating can be secured. Experimentally, the temperature of the condenser 6 was measured with a 1 mm diameter sheathed thermocouple and found to be 500 ° C. to 800 ° C. By using the infrared heating apparatus of FIG. 1, the wire can be run at a speed of 1,000 mm / sec to 2,000 mm / sec and cured without foaming the resin bond.

As an infrared heating method, an infrared laser irradiation method may be used.

The paste is mixed with a filler made of inorganic particles. The filler suppresses the thermal expansion / contraction of the resin bond and reduces the falling off of abrasive grains during cutting. The filler is preferably blended in an amount of 20 to 100 parts by weight, more preferably 30 to 60 parts by weight based on 100 parts by weight of the resin bond. As the filler, diamond fine particles having a size of about 2 to 3 μm are suitable, but other inorganic materials (for example, silicon carbide fine particles) can also be used.

¡Reheating the resin bond wire saw that has been heated by infrared heat stabilizes the performance. By reheating, the thermal strain generated in the wire and paste during infrared heating can be removed. Reheating hardly changes the breaking stress of the resin bond wire saw or the molecular structure of the resin bond.

Reheating is preferably performed at a temperature of 100 ° C. to 200 ° C. for 1 hour to 5 hours. Although the reheating time is long, a large number of bobbins wrapped with the resin bond wire saw can be reheated at a time, so that the productivity of the resin bond wire saw is not greatly reduced by reheating. By combining infrared heating and reheating, high productivity of the resin bond wire saw can be obtained.

The resin bond wire saw of the present invention has a greater cutting depth than conventional resin bond wire saws. The “cut depth” refers to the cut depth when the test piece is cut and the wire saw is broken. Wire saw breakage is mainly caused by the falling off of abrasive grains. The resin bond wire saw of the present invention has a larger cutting depth because the fixing strength of the abrasive grains is larger than that of a conventional resin bond wire saw.

The resin bond wire saw of the present invention is 25% or more superior to conventional resin bond wire saws in terms of wafer warpage, undulation, and thickness variation (TTV). With the resin bond wire saw of the present invention, a wafer having a surface roughness (Ra, Ry) of about 20% smaller than that of a conventional resin bond wire saw can be obtained. With the resin bond wire saw of the present invention, it is possible to obtain a wafer having a small surface damaged layer. With the resin bond wire saw of the present invention, a wafer with high bending strength can be obtained.

The cutting performance of the resin bond wire saw of the present invention was confirmed by the following experiment.

Using a resin bond having the following composition, a paste having the following composition was prepared, and a resin bond wire saw was produced by the next production line.

[Example 1]
(1) Compounding resin bond

(2) Paste formulation

(3) Resin bond wire saw production line (a) Outline of wire Wire feeding machine → Coating device → Heating device → Winding machine → Reheating furnace (b) Wire feeding machine: A device for feeding out the wire wound around the bobbin.
(C) Coating device: A device that coats the wire surface uniformly with a water jet-shaped die.
(D) Heating device: a device for heating the wire coated with the paste.
Infrared Gold Image Furnace manufactured by ULVAC-RIKO, Inc .: Model RHL-E410-N (heating length 265 mm, maximum output 4 kW) was used in series. FIG. 2 shows the energy spectral distribution of the lamp.
(E) Winder: A device for winding a resin bond wire saw onto a bobbin.
(F) Reheating furnace: A convection heating furnace for heating a resin bond wire saw wound around a bobbin by a winder.
(4) Material and production conditions (a) Wire: Piano wire (wire diameter: 120 μm, breaking strength: about 42 N).
(B) Travel speed of the wire: 1200 mm / sec.
(C) Paste coating amount: 0.01 g / m.
(D) Temperature of infrared gold image furnace: 720 ° C. to 750 ° C. (thermocouple measurement).
(The temperature at which the breaking strength of the resin bond wire saw does not become less than 40N.)
(E) Temperature and time in the reheating furnace: 180 ° C., 2 hours.

[Example 2]
(1) Compounding resin bond

(2) Paste formulation

A resin bond wire saw was manufactured in the same manner as in Example 1 except for the above.

[Comparative example]
A commercially available novolac type phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd.) was used as the resin bond, and a vertical enamel baking furnace was used as the heating device. A vertical enamel baking furnace heats a wire with heated air circulating in the furnace core tube. The heating element is a nichrome wire. In a vertical enamel baking furnace, heating was performed at a furnace temperature of 300 ° C. and a heating time of 20 minutes. Others were carried out similarly to Example 1, and obtained the resin bond wire saw.

The cutting depth of the resin bond wire saws of Examples 1 and 2 was compared with the cutting depth of the resin bond wire saws of the comparative examples.
(1) Cutting depth test method A polycrystalline silicon piece of 1 cm × 1 cm × 2 mm was set above a horizontally stretched resin bond wire saw, and the polycrystalline silicon piece was moved downward to measure the cutting depth. . Piece descending speed: 0.9 mm / min.
(2) Cutting conditions Resin bond wire motion: reciprocating motion with an amplitude of 80 mm and a speed of 400 mm / min.
(3) Cutting time: Until disconnection.

Table 1 shows the results of the cutting depth test. Table 2 shows the remaining rate of the abrasive grains of the wire after the test.

As shown in Table 1, the cutting depth of the resin bond wire saws of Examples 1 and 2 is about 1.7 times the cutting depth of the resin bond wire saw of the comparative example. As shown in Table 2, the residual abrasive rate of the resin bond wire saw of Example 1 is about 1.8 times the residual abrasive rate of the resin bond wire saw of Comparative Example.

In order to investigate the reason for this difference, the hardness of the cured resin bond was examined.
Case 1: The resin bond used in Example 1 was cured by heating. Heating conditions: The temperature was raised from room temperature to 180 ° C. at 15 ° C./hour and held at 180 ° C. for 2 hours.
Case 2: The novolac type phenol resin used in the comparative example was heat-cured under the same heating conditions as in Case 1.

The Rockwell hardness of the obtained cured product was measured using a hardness meter (ATK-F3000; 1/4 “steel ball used, load 100 kgf) manufactured by Akashi Seisakusho. The results are shown in Table 3.

From Table 3, it can be seen that the resin bond of Example 1 is higher in hardness than the resin bond of the comparative example. This is one of the reasons why the resin bond wire saw of the present invention has a large depth of cut.

[analysis]
The network molecular structure and physical properties of the resin bond of Example 1 and the resin bond of the comparative example were examined.

Mass spectrometry was performed by the MALDI-TOF-MS method. (MALDI: matrix-assisted laser desorption ionization method, TOF-MS: time-of-flight mass spectrometry).
-Equipment used: AXIMA-CFR ⁺ (SHIMADZU) manufactured by Shimadzu Corporation.
-Analysis mode: Linear mode (positive ion, anion detection).
・ Vacuum degree: 10 ⁻⁵ Pa or less.
Matrix: 2,5-dihydroxybenzoic acid.
Laser wavelength: 337 nm (nitrogen laser).

Figures 3 to 6 show measurement charts for mass spectrometry using the MALDI-TOF-MS method. FIG. 3 is a cation detection chart of the resin bond of the comparative example. 4 is a cation detection chart of the resin bond of Example 1. FIG. FIG. 5 is an anion detection chart of the resin bond of the comparative example. FIG. 6 is an anion detection chart of the resin bond of Example 1.

In FIG. 4 (Example 1), peaks (arrows) showing fragments at intervals of 208 (m / z) can be seen. It is presumed that the 208 (m / z) -spaced fragments were generated as a result of cleavage (fragment) of the bridge at four sites including the aromatic ring in the following structural formula (structural unit; C ₁₄ H ₁₂ O ₂ : molecular weight 212). Is done.

This indicates that in the resin bond of Example 1, the following structure is regularly arranged as a repetitive fragment in a network polymer structure.

In FIGS. 3, 5, and 6, peaks (arrows) indicating fragments at regular intervals were not detected. Therefore, it seems that the resin bond of the comparative example does not have the structure represented by Chemical Formula 1.

From the results described above with reference to FIGS. 3 to 6, it is considered that the molecular structure showing fragments of 208 (m / z) spacing was generated by heating the resin bond with infrared rays.

In FIG. 7, the differential thermal analysis chart of the resin bond of Example 1 and the resin bond of a comparative example is shown.
-Device used: TG8120 (Rigaku).
Temperature rising rate: 10 ° C./min (min)
Atmosphere: N ₂ gas flow.
Reference material: Alumina (Al ₂ O ₃ ).
Sample weight: about 10 mg.

7 shows a clear softening point peak at 175 ° C. to 182 ° C. in the resin bond chart of Example 1 shown in FIG. On the other hand, in the resin bond of the comparative example, only an unclear peak of the softening point is observed around 190 ° C. Since the resin bond of the comparative example has a non-uniform high-order structure, no transition accompanied by a structural change occurs and no clear softening point peak is observed. The resin bond of Example 1 seems to have high hardness because it has a higher-order structure with fragments of 208 (m / z) intervals. The reason why the resin bond of the comparative example has a low hardness seems to be because the higher order structure is not uniform.

When the resin bond wire saw of the present invention is used, a high-quality wafer can be efficiently cut out from a silicon ingot.

Claims

A resin bond wire saw in which abrasive grains are fixed to the surface of the wire by a resin bond mainly composed of a phenol resin,
The resin bond shows a plurality of peaks representing fragments of 208 (m / z) spacing in the cation in mass analysis by MALDI-TOF-MS method,
A resin bond wire saw showing a peak corresponding to a softening point at 175 ° C. to 182 ° C. in a differential thermal analysis by the TG-DTA method.
The resin bond according to claim 1, wherein the resin bond includes 100 parts by weight of a novolac type phenol resin, 10 parts by weight to 30 parts by weight of a resole type phenol resin, and 0.1 part by weight to 5 parts by weight of an amine silane coupling agent. Wire saw.