JP2015136745A - Wire rod for wire saw, and wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire saw having high durability.SOLUTION: A wire rod for a wire saw includes: a core wire comprising quartz fiber; a resin layer formed on the outer periphery of the core wire, and protecting the core wire; a conductive layer formed on the outer periphery of the resin layer; and an abrasive grain holding layer formed on the outer periphery of the conductive layer by plating and having a coating thickness thicker than that of the conductive layer. An elongation value of resin of the resin layer is 5% or more, a coefficient of elasticity of resin of the resin layer is 800 MPa or more, a ratio of an elongation of resin of the resin layer to an elongation of the metal of the abrasive grain holding layer is 1.0 or more, and an adhesion strength to glass of the resin layer, for evaluating a peeling force required when applying resin to be used in the resin layer to a glass plate surface and peeling the resin in a peeling testing is 2.0 N/mm or more.

Description

  The present invention relates to a wire saw or the like capable of cutting a wafer from a difficult-to-cut material such as a silicon ingot.

  Conventionally, for example, in order to obtain a silicon wafer by slicing a silicon ingot, a wire has been used. For example, there has been a method of slicing an object to be processed while supplying a slurry containing abrasive grains using a steel wire.

  However, in such a method, a grinding waste liquid containing a large amount of abrasive grains and workpiece cutting waste is generated. Therefore, there is a problem that this processing is necessary and the environmental load is large.

  Therefore, there is a method of using a wire saw in which abrasive grains are held by a resin on the outer periphery of a metal wire such as a piano wire. Such a method eliminates the need for a large amount of waste liquid.

  However, in a cutting method using a wire saw having a metal wire such as a piano wire as a core, the workpiece is usually cut in a state where tension is applied to the wire. For this reason, there is a problem of wire breakage. For this reason, in order to ensure durability, it is necessary to make a wire diameter more than predetermined. However, when the wire diameter is increased, the cutting allowance is increased, so that there is a problem that the yield is lowered.

  On the other hand, there is a method using a wire saw using quartz glass as a core material (Patent Document 1).

JP 2012-228771 A

  Since the method of patent document 1 uses quartz glass with high tensile strength for a core material, it can make a wire saw with a small wire diameter. Moreover, since the resin layer is formed in the core wire outer periphery, it can prevent that an abrasive grain contacts a core material.

  However, when tension is applied to the wire saw, the resin layer or the like may be broken even if the core material can sufficiently withstand the tension. In this case, since the core material is exposed, the core material and the work body or the like may come into contact with each other, and the core material may be broken.

  This invention is made | formed in view of such a problem, and it aims at providing the wire saw etc. which have high durability.

  In order to achieve the above-described object, the first invention includes a core wire made of quartz fiber, a resin layer formed on the outer periphery of the core wire to protect the core wire, a conductive layer formed on the outer periphery of the resin layer, An abrasive grain holding layer having a coating thickness greater than that of the conductive layer formed by plating on the outer periphery of the conductive layer, and an elongation value of the resin of the resin layer is 5% or more; The elastic modulus of the resin layer is not less than 800 MPa, and the elongation of the resin of the resin layer covering the core wire / the elongation of the metal of the abrasive grain holding layer is not less than 1.0. The wire saw wire material is characterized in that the adhesion strength to glass of the resin layer, which has been evaluated for a peeling force required when the resin is applied to the surface and peeled off by a peel test, is 2.0 N / mm or more.

  The resin layer preferably has a thickness of 10 to 30 μm, and the outermost plating layer is made of any metal of nickel, copper, and tin.

The fine particles forming the conductive layer are conductive particles, the thickness of the conductive layer is preferably 2 to 10 μm, and the volume resistivity of the conductive layer is preferably in the range of 10 ⁻³ to 10 ⁻⁶ .

  The core wire preferably has an outer diameter of 60 to 300 μm and a tensile strength of 5000 MPa or more.

  According to the first invention, since the core wire is made of quartz fiber, it has a higher tensile strength than the conventionally used piano wire. Therefore, the core wire diameter can be made thinner than the core wire of a wire saw using a piano wire. Therefore, it is possible to obtain a wire saw that is excellent in wire durability and has a high yield of work material during cutting.

  Moreover, since the elongation of the resin layer is 5% or more, the resin layer can be prevented from breaking when tension is applied to the core wire. In particular, since the elongation of the resin in the resin layer / the elongation of the metal in the plating layer is 1.0 or more, the resin layer can be more reliably prevented from breaking. Moreover, since the adhesiveness of the resin layer and glass is excellent, it can suppress that a core wire falls out from a resin layer. Furthermore, since the elastic modulus of the resin layer is 800 MPa or more, it is possible to suppress the abrasive grains from being embedded in the resin layer.

  Moreover, if the thickness of a resin layer is 10-30 micrometers, a core wire can be efficiently protected from an abrasive grain. Moreover, since the plating layer is made of any metal of nickel, copper, and tin, plating is easy and the abrasive grains can be reliably held.

Moreover, if the thickness of the conductive layer is 2 to 10 μm and the volume resistivity of the conductive layer is in the range of 10 ⁻³ to 10 ⁻⁶ , plating for forming the plating layer is easy.

  Moreover, if the outer diameter of a core wire is 60-300 micrometers and a tensile strength is 5000 Mpa or more, the loss at the time of a cutting | disconnection will be few and the fracture | rupture of a core wire can also be suppressed. The outer diameter of the core wire is desirably 60 to 300 μm.

  2nd invention uses the wire material for wire saws, comprises the said plating layer formed in the outer periphery of the said conductive layer, and the abrasive grain hold | maintained at the said plating layer, and the said plating layer is formed by plating. It is a wire saw characterized by this.

  According to the second aspect of the invention, it is possible to prevent the wire saw from being broken and to slice the cutting object with high efficiency and reliability.

  ADVANTAGE OF THE INVENTION According to this invention, the wire saw etc. which have high durability can be provided.

The figure which shows the cutting device 1. FIG. Sectional drawing of the wire saw 7. FIG. Schematic which shows the fiber manufacturing apparatus 20. FIG. Schematic which shows the wire saw manufacturing apparatus 40. FIG. The figure which shows the wire saw wire breaking strength measuring apparatus 60. FIG. It is a figure which shows the fracture | rupture state of the wire material for wire saws, (a) is a figure which shows the state which the whole fracture | ruptured, (b) is a figure which shows the state by which the resin layer 13 grade | etc., Was fractured | ruptured. The figure which shows the evaluation method of the fracture resistance of the wire 35 for wire saws.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a cutting device 1. The cutting device 1 omits the illustration of the holding unit 5 that holds the ingot 3 that is the object to be cut, the roller 9 that has multiple grooves for moving the wire saw 7, and the driving unit 5 and the roller 9. Consists of a motor and the like. The object to be cut is a hard or brittle material such as silicon or sapphire, SiC, a compound semiconductor, glass, or ceramics.

  In the cutting device 1, the wire saw 7 is wound many times around the outer periphery of the roller 9 with a predetermined tension applied. The wire saw 7 is fed from one side (in the direction of arrow A in the figure) and wound up from the other side (in the direction of arrow B in the figure). By rotating the roller 9 reversibly by the drive motor, the wire saw 7 can be reciprocated between the rollers 9.

  In a state where the ingot 3 such as silicon for semiconductor is held by the holding portion 5, it is moved perpendicularly to the moving direction of the wire saw 7 (in the direction of arrow C in the figure). The ingot 3 is cut by the wire saw 7 by applying a predetermined load to the holding portion 5 and bringing the ingot 3 into contact with the wire saw 7. That is, the ingot 3 can be sliced into a large number of workpieces at a time. The cutting method of the present invention is not limited to the illustrated example, and can be applied to all cutting processes performed using the wire saw according to the present invention. When cutting with the wire saw 7, cutting is performed while applying lubricating oil in order to reduce the load caused by the frictional force on the wire during cutting.

  Next, the wire saw 7 will be described. FIG. 2 is a cross-sectional view of the wire saw 7. The wire saw 7 is mainly composed of a core wire 11, a resin layer 13, a conductive layer 15, a plating layer 17, an abrasive grain 19, and the like.

(Core material)
The core wire 11 is a quartz fiber having an outer diameter of 60 to 300 μm. If the diameter of the core wire 11 is too thin, the wire saw may be broken during use. Further, if the diameter of the core wire 11 is too large, the cutting allowance of the object to be cut increases, so that the yield decreases and a large amount of chips may be generated. For example, when a high-purity silica fiber is used, a glass fiber that is vapor-phase synthesized is used, does not contain impurities, and has a high tensile strength. The core wire 11 preferably has a tensile strength of 5000 MPa or more. As such a core wire 11, for example, a glass fiber conventionally used as an optical fiber can be used. If such a high purity silica fiber is used, the elastic modulus of the core material becomes 72000 MPa.

(Resin layer)
A resin layer 13 is provided on the outer periphery of the core wire 11. The resin layer 13 is for protecting the core wire 11.

  As described above, the quartz fiber has a very high tensile strength. However, if the quartz fiber material is non-uniform or any defects are present in the inside or the surface of the material, there is a risk of breakage against bending deformation. For this reason, by covering the periphery of the core wire 11 with the resin layer 13, it is possible to prevent stress when the wire saw 7 is bent from being concentrated on one place of the wire saw 7, and to prevent breakage of the core wire 11. . For this reason, even if the wire saw 7 is wound around a bobbin or the like, and the winding apparatus 1 is wound between the rollers 9, the wire saw 7 can be prevented from being broken.

  Further, the resin layer 13 prevents contact between abrasive grains 19 and the core wire 11 described later. That is, the core wire 11 can be prevented from being damaged by contact with the abrasive grains 19, and the breakage of the core wire 11 due to this can be prevented.

  In order to impart bendability to the wire saw 7 and prevent the abrasive grains 19 from biting in, the thickness of the resin layer 13 is preferably 10 to 30 μm. When the resin layer 13 is 10 μm or less, the effect of preventing stress concentration when the wire saw 7 is bent is insufficient, and the prevention of the biting of the abrasive grains 19 becomes insufficient. Further, if the thickness of the resin layer 13 exceeds 30 μm, the outer diameter of the wire saw 7 is increased, the yield at the time of cutting the work material is deteriorated, and it takes time to cure the resin when forming the resin layer 13. .

  In consideration of the bendability of the wire saw 7 and the prevention of the biting of the abrasive grains 19, the elastic modulus of the resin layer 13 is desirably 800 MPa or more. When the elastic modulus is less than 800 MPa, the ability of the abrasive grains 19 to bite becomes insufficient.

  In consideration of the bendability of the wire saw 7, if the elastic modulus of the resin layer 13 becomes too large (for example, exceeding 5000 MPa), the bendability of the wire saw 7 is deteriorated and may cause breakage. The upper limit of the elastic modulus is preferably 5000 MPa or less, although it is designed appropriately according to the use conditions. The elastic modulus of the resin layer 13 may be adjusted by adjusting the molecular weight, the degree of polymerization, the degree of crosslinking, the particle size of the filler, and the amount added.

  The elongation of the resin constituting the resin layer 13 is desirably 5.0% or more. If the elongation of the resin layer 13 is less than 5.0%, the resin layer 13 cannot follow the elongation of the core wire 11 and other layers, and the resin layer 13 may be broken. Even if the core wire 11 is not broken, if the resin layer 13 is broken, a part of the core wire 11 comes out of the resin layer 13 and is exposed. For this reason, stress concentration may occur in the exposed portion of the core wire 11 and the core wire 11 may be broken.

  Note that when the elongation of the resin increases, generally the elastic modulus of the resin tends to decrease. For this reason, for example, if the resin layer 13 is stretched too much (for example, exceeding 100%), the resin layer 13 is sheared during cutting, and the plating layer holding the abrasive grains is deformed and cut. May be worse. For this reason, the elongation of the resin layer 13 is appropriately designed according to usage conditions and the like. That is, as the resin constituting the resin layer 13, it is desirable to select a resin having an elongation of 5.0% or more and an elastic modulus of 800 MPa or more.

  Moreover, it is desirable that the adhesion strength between the resin layer 13 and the core wire 11 is 2.0 N / mm or more. The adhesion strength between the resin layer 13 and the core wire 11 is evaluated by a peeling force required when the resin used for the resin layer 13 is applied to the glass plate surface and the resin is peeled off in a peel test. When the adhesion strength between the resin and the glass is less than 2.0 N / mm, the core wire 11 may easily come off from the resin layer 13. However, when the adhesion strength is 2.0 N / mm or more, the glass and the resin layer of the core wire are likely to come out. Therefore, the resin layer does not come off from the core wire.

  In addition, as such a resin layer 13, any resin is applicable. For example, a radical curable ultraviolet curable resin such as urethane acrylate or epoxy acrylate, an epoxy resin cation curable ultraviolet curable resin, an epoxy or polyimide thermosetting resin can be applied. In addition, an ultraviolet curable resin is preferable from the viewpoint of productivity.

(Conductive layer)
A conductive layer 15 is provided on the outer periphery of the resin layer 13. The conductive layer 15 is a layer for forming a plating layer 17 to be described later, and is a layer for forming a plating layer 17 to be described later on the outer periphery of the core wire coated with resin. The conductive layer 15 is formed between the resin layer 13 and the plating layer 17 that is an abrasive grain holding layer. For this reason, when the conductive layer 15 is deformed, it also serves as a buffer layer that absorbs stress during cutting and prevents the abrasive grains 19 carried on the plating layer 17 from biting into the resin layer 13. Since the role as the buffer layer is incidental, it is desirable that the thickness of the conductive layer be as thin as possible as long as sufficient conductivity can be imparted.

The conductive layer 15 is obtained by adding metal particles 16 such as silver or copper to an ultraviolet curable resin. In consideration of conductivity, the metal particles 16 are preferably silver. The volume resistivity of the conductive layer 15 may be, for example, about 10 ⁻³ to 2 × 10 ⁻⁶ Ω · cm, but is preferably lower. This is because if the volume resistivity is too high, it is difficult to form the plating layer 17. Further, if the metal particles 16 are added excessively in order to reduce the volume resistivity, the metal particles conversely block the ultraviolet rays so that the ultraviolet rays do not reach the entire ultraviolet curable resin constituting the conductive layer 15, and the resin It is because it becomes difficult to harden.

That is, the addition amount of the metal particles 16 is set so as to have the above-described volume resistivity. For example, it is possible to achieve the volume resistivity of the conductive layer within the above range by dispersing silver particles in the conductive layer with a volume resistivity of 1.6 × 10 ⁻⁶ Ω · cm. 10 ^{−3 to} 2 × 10 ⁻⁶ Ω · cm.

  In order to form the plating layer 17 stably, the volume resistivity of the conductive layer 15 needs to be in the above range. Therefore, it is desirable that the metal particles have a smaller volume resistivity because the resistance of the conductive layer can be lowered. Further, if metal particles having a low volume resistivity are used, the conductive layer 15 can be made thin. Therefore, the volume resistivity of the metal particles used for the conductive layer 15 is preferably as low as possible.

  In addition, the conductive layer 15 should just be able to form the plating layer 17 uniformly on an outer surface, for example, the layer thickness of a conductive layer is 2-10 micrometers, and the particle diameter of a metal particle is according to the layer thickness of a conductive layer. Just decide. For example, when the layer thickness of the conductive layer is 10 μm, if the particle diameter of the metal particles exceeds 10 μm, the diameter of the wire saw 7 increases as well as exceeding the layer thickness of the conductive layer. Therefore, the particle diameter is desirably 10 μm or less, and considering the arrangement of the particles in the conductive layer, the maximum value of the particle diameter is desirably 8 μm or less in practice. Moreover, as a lower limit of the particle diameter, since the diameter of the metal particles that can be used is limited in terms of cost and the like, the particle diameter of the metal particles is preferably 0.1 μm or more. Therefore, the particles used for the conductive layer are preferably 0.1 μm or more and 8 μm or less, and more preferably 0.1 μm or more and 6 μm or less.

(Plating layer)
The plating layer 17 is an abrasive grain holding layer that fixes the abrasive grains 19 by metal plating. The plating layer 17 may be any metal as long as it can hold the abrasive grains 19, but is preferably composed of nickel, copper, tin, silver, or gold, and in particular, copper, tin, silver, gold It is desirable to use a soft metal such as

  Here, it is desirable that the elongation of the resin in the resin layer 13 / the elongation of the metal in the plating layer 17 is 1.0 or more. That is, it is desirable that the resin of the resin layer 13 has a larger elongation than the metal of the plating layer 17. If the elongation of the resin layer 13 is smaller than the elongation of the plating layer 17, the resin layer 13 may be broken first, and the core wire 11 may come out of the resin layer 13. On the other hand, if the elongation of the resin layer 13 is larger than the elongation of the plating layer 17, the deformation of the resin layer 13 can follow the deformation of the plating layer 17.

(Abrasive grains)
The type and average particle size of the abrasive grains 19 are appropriately changed depending on the type and hardness of the workpiece, but the type of the abrasive grains 19 is preferably diamond. From the viewpoint of adhesion and productivity, metal-coated diamond such as nickel, titanium, palladium, etc. may be used. In this case, the average grain size of the abrasive grains 19 is desirably 5 to 50 μm. If the diameter of the abrasive grains 19 is too small, the cutting ability is inferior. On the other hand, if the particle size is too large, it is necessary to increase the thickness of the plating layer 17 for holding the particle size, so that the outer diameter of the wire saw 7 increases and the yield decreases.

(Wire saw manufacturing method)
Next, a method for manufacturing the wire saw 7 will be described. FIG. 3 is a schematic view showing a core wire manufacturing apparatus 20 for manufacturing the wire saw 7. In the present invention, the production method is not limited as long as the above-described quartz fiber having the tensile strength can be produced.

  First, the fiber preform 21 is manufactured. What is necessary is just to manufacture the glass fine particle deposit body which is the fiber preform | base_material 21 by the OVD method (Outside Vapor Deposition method) etc., for example. In the OVD method, a glass material containing silicon is introduced into a burner together with a combustion gas such as a flammable gas and an auxiliary combustible gas, and the glass material is hydrolyzed or oxidized in a flame. In this method, an aggregate is generated and is deposited on the outer periphery of a mandrel serving as a rotating deposition target to form a glass particulate deposit. The fiber preform 21 can be obtained by making the glass particulate deposits transparent in a furnace.

  The obtained fiber preform 21 is drawn by the core wire manufacturing apparatus 20. The core wire manufacturing apparatus 20 includes a heater 23, resin layer coating dies 25 and 29, ultraviolet irradiation devices 27 and 31, a winding device 37, and the like.

  First, the fiber preform 21 is heated and melted by the heater 23 and drawn (in the direction of arrow E in the figure) to obtain a bare fiber 33 having a predetermined diameter. Thereby, a core wire of 60-300 micrometers is obtained. Next, the bare fiber wire 33 is passed through the resin layer coating die 25 to which the liquid resin heated to a certain temperature is supplied, and the liquid resin is applied to the outer periphery. Here, the clearance of the resin layer coating die 25 is set to about twice the coating thickness larger than the coating thickness in consideration of curing shrinkage after ultraviolet irradiation, for example. Next, the liquid resin applied by the ultraviolet irradiation device 27 is cured to form the resin layer 13. Thereafter, the conductive layer 15 is formed by the resin layer coating die 29 and the ultraviolet irradiation device 31 using the ultraviolet curable resin to which metal particles or the like are added. In addition, when using a thermosetting resin, after preheating with the ultraviolet irradiation device 27, it passes the heating oven as an auxiliary heating device, or changes to the ultraviolet irradiation device 27 set to predetermined temperature. It is necessary to use a heating oven.

  The obtained wire saw wire 35 is wound up by a winding device 37 (in the direction of arrow F in the figure).

(Plating layer formation method)
Next, the electrodeposition process of abrasive grains will be described. FIG. 4 is a schematic view showing the wire saw manufacturing apparatus 40. First, wire saw wire 35 is sent to degreasing tank 41 (in the direction of arrow G in the figure). The degreasing tank 41 is a tank in which, for example, an aqueous sodium hydroxide solution is stored, and dirt such as oil adhering to the outer surface of the wire saw wire 35 is removed. In the washing tank 43, the chemical solution or the like of the degreasing tank 41 attached to the surface is washed.

  The plating tank 45 is a tank for electrolytically plating the wire saw wire 35 and electrodepositing diamond abrasive grains. The plating tank 45 is, for example, a nickel bath in which abrasive grains are dispersed in a solution in which nickel is dissolved. A cathode 49 is connected to the wire saw wire 35 that passes through the plating tank 45. Further, the anode 51 is immersed in the plating tank 45. The cathode 49 and the anode 51 are connected to a power source (not shown). Thus, a plating layer having a desired thickness is formed.

  In addition, what was previously processed in the cationic surfactant solution is used for the abrasive grains. By doing in this way, a positive electric charge can be given to an abrasive grain. Accordingly, the abrasive grains can be adsorbed to the wire saw wire 35 connected to the cathode 49 by the Coulomb force.

  In a state where the abrasive grains are held by the plating layer, excess chemicals and the like are washed in the water washing tank 47 and wound up by the winding device 53 (in the direction of arrow H in the figure), whereby a wire saw is manufactured.

  According to the present invention, since the core wire 11 is made of quartz fiber, it has a higher tensile strength than, for example, a conventional piano wire. For this reason, it is possible to suppress breakage of the wire saw and to reduce the outer diameter of the wire saw.

  Further, in order to prevent breakage of the core wire 11, a resin layer 13 is provided on the outer periphery of the core wire 11. Since the elongation of the resin of the resin layer 13 is 5.0% or more and the elastic modulus is 800 MPa or more, the resin layer 13 can be prevented from being broken and the abrasive grains 19 can be prevented from being pushed in.

  Moreover, since the elongation of the resin of the resin layer 13 / the elongation of the metal of the plating layer 17 is 1.0 or more, it is possible to prevent the resin layer 13 from breaking first and the core wire 11 from coming off.

  In addition, since the resin layer 13 has a resin-to-glass adhesion strength of 2.0 N / mm or more, the resin layer 13 can be prevented from peeling from the core wire 11.

  Moreover, since the thickness of the resin layer 13 is 10-30 micrometers, it can suppress that the abrasive grain 19 is embedded and contacts the core wire 11. FIG.

  Moreover, if the outer diameter of the core wire 11 is 60 to 300 μm and the tensile strength is 5000 MPa or more, loss at the time of cutting is small, and breakage of the core wire 11 can be suppressed.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs.

  Hereinafter, breaking characteristics and the like were evaluated using various wire saw wires. First, Table 1 shows the resins used in the evaluation.

  Here, the UV curable resin has an elongation value adjusted in the range of 5 to 200% depending on the molecular weight of the urethane acrylate oligomer, the number of functional groups, and the presence or absence of monomer addition. In addition, the thermosetting resin was adjusted in the same manner using an epoxy oligomer, and two materials having elongation values of 2% and 15% were prepared. Further, the glass adhesion was adjusted by adding a silane coupling agent.

  The elongation and Young's modulus (elastic modulus) of each resin were measured by preparing a resin film and measuring the tensile elongation at break and 2.5% modulus according to JIS K7161.

  The glass adhesion strength of the cured resin was measured by the following method. First, a resin was applied to a thickness of 50 μm on a cleaned glass plate by a spin coater or a bar coater. Next, the sample was sufficiently cured by a 1500 mW, 1000 mJ UV lamp. The obtained sample was cut into a width of 10 mm, and the glass adhesion of the cured resin was measured by measuring the stress at the time of peeling by 90 degrees with a tensile tester.

  The UV curable resins A and B have an adhesion force with glass of less than 2.0 N / mm. The UV curable resins G and H have a Young's modulus of less than 800 MPa. The thermosetting resin A has an elongation of less than 5.0%. Other resins satisfy an elongation of 5.0% or more, a Young's modulus of 800 MPa or more, and an adhesive strength of 2.0 N / mm or more with glass.

Example 1
Next, a resin layer was formed using each resin, a wire saw wire material having a nickel plating of 5% elongation was prepared as a plating layer, and the presence or absence of a core wire of the wire saw was removed and a side pressure fracture test was performed.

  Specifically, a resin layer or the like was formed using the resin shown in Table 1. The resin layer had a thickness of 20 μm and the conductive layer had a thickness of 6 μm. For the formation of the conductive layer, Ag particles having a particle size of 4 μm or less and an average particle size of 1 μm were used.

  FIG. 5 is a schematic diagram showing a wire saw wire breakage evaluation device 60. First, a resin layer having a predetermined thickness was formed on the outer periphery of a glass fiber core wire drawn to an outer diameter of 125 μm, and a conductive layer having a predetermined thickness was formed on the outer periphery thereof. The wire saw wire thus obtained was subjected to electroplating to form an abrasive grain retaining layer having a predetermined thickness, whereby a wire saw wire 35 was obtained.

  Next, both ends of the wire saw wire 35 were fixed to the glass plate 61 with an adhesive 63 to a length of 10 mm. Thereby, the outermost layer of the wire material 35 for wire saws and the glass plate 61 adhere | attach. Next, the glass plates 61 at both ends are fixed by a chuck portion of a pulling device (not shown). The distance between the glass plates 61 (between marked lines) when fixed was 25 mm.

  Fig.6 (a) is a figure which shows a fracture | rupture state at the time of providing the tensile force (I in the figure) to the wire material 35 for wire saws. In the example shown in FIG. 6A, the resin layer 13, the conductive layer 15, and the plating layer 17 are broken together with the core wire 11. That is, in such a ruptured state, the core wire 11 does not come off from the resin layer 13 and is not exposed to the outside until just before the core wire 11 is broken.

  FIG.6 (b) is a figure which shows the other fracture | rupture state at the time of providing the tensile force (J in a figure) to the wire 35 for wire saws. In the example shown in FIG. 6B, the resin layer 13 and the like are broken before the core wire 11 is broken. Therefore, the core wire 11 comes off from the resin layer 13 and is exposed outside. When the core wire 11 is exposed, the core wire 11 is easily broken by bending or contact with a workpiece. That is, there is a possibility of breaking even in a situation where the tensile strength of the core wire 11 or less.

  In this way, by pulling one end of the fixed sample in the vertical direction, a load in the shear direction is applied, and the breaking type of the wire saw wire 35 is broken as a whole, or the core wire 11 is detached from the resin layer 13 or the like. The occurrence was observed visually. In addition, the thing with which the missing of the core wire 11 occurred was set as “X”, and the case where the missing did not occur was marked as “◯”.

  Fig.7 (a) is a figure which shows the test method of the side pressure breaking strength of the wire 35 for wire saws. First, the wire saw wire 35 was disposed between the pair of metal plates 55, and the load K was applied so that the wire saw wire 35 was sandwiched between the metal plates 55. The metal plate 55 was 8 mm long.

  As shown in FIG. 7B, diamond abrasive grains 57 were previously fixed to the surface of the metal plate 55 with an adhesive. That is, the wire saw wire 35 is pressed from above and below by the diamond abrasive grains 57. At this time, the load applied to the metal plate 55 was increased by 1 kg, and the load when the wire saw wire 35 was broken was measured. That is, it shows that it is a wire material for wire saws which is excellent in fracture resistance and is hard to fracture, so that the numerical value (kg) of side pressure fracture resistance is large.

  The side pressure rupture resistance value of 3 kg or more was judged as ◯ with reference to the tension that could be applied in the actual machine, and less than 3 kg was marked as x. In addition, as a comprehensive determination, a case where there was no core wire missing and exceeded 3.0 kg in the side pressure rupture resistance test was evaluated as “good”, and when any of the evaluation items had “×”, the determination was “x”. The results are shown in Table 2.

  As shown in Table 2, No. 1 using a resin having low adhesion to glass. As for Nos. 1 and 2, since the core wire was missing, the judgment was x. No. 1 using a resin with a low Young's modulus. 7 and 8, the result of the side pressure rupture resistance test was x. In addition, the elongation of the resin is small and the ratio of the plating layer to the elongation of the metal (5%) is less than 1.0. No. 9 was marked X because a core wire was missing. Other samples were evaluated as “good” because the elongation, Young's modulus, adhesion to glass, and the like were within the scope of the present invention.

(Example 2)
Next, in the same manner as in Example 1, a resin layer was formed using each resin, and a nickel-plated wire saw wire having a different elongation was produced as a plating layer. A side pressure rupture test was performed. Here, in nickel plating, the elongation value was changed to 5% and 15% by changing the plating solution composition and the plating temperature and adjusting the plating hardness. The resin layer had a thickness of 24 μm, the conductive layer had a thickness of 4 μm, and Cu particles having a particle diameter of 2 μm or less and an average particle diameter of 0.5 μm were used for forming the conductive layer. The results are shown in Table 3.

  No. In each of 11 to 13, since the elongation, Young's modulus, adhesion to glass, and the like are within the scope of the present invention, all the evaluations were good.

(Example 3)
Next, in the same manner as in Example 1, a resin layer was formed using each resin, and a wire saw wire material having Cu plating with an elongation of 10% was prepared as a plating layer. A side pressure rupture test was performed. The resin layer had a thickness of 20 μm, the conductive layer had a thickness of 5 μm, and the conductive layer was formed using Ag particles having a particle size of 2 μm or less and an average particle size of 0.5 μm. The results are shown in Table 4.

  No. In No. 14, the elongation was 5.0% or more, but the ratio of the plating layer to the metal elongation (resin elongation / metal elongation) was less than 1.0, so that the core wire was missing. This is because the resin broke before the metal and the core wire and the resin were peeled off. No. whose Young's modulus is less than 800 MPa. Nos. 17 and 18 had x in the side pressure fracture test. Other samples were evaluated as “good” because the elongation, Young's modulus, adhesion to glass, and the like were within the scope of the present invention.

Example 4
Next, the thickness of the resin layer and conductive layer of the wire saw wire and the productivity of the wire saw were evaluated. The results are shown in Table 5. At this time, particles having an average particle size of 0.4 μm and a particle size of less than 1 μm of metal particles added to the conductive layer were used.

  No. The resins used in 19 to 25 all extend and satisfy the scope of the present invention in terms of glass adhesion and strength. However, no. No. 19 was not able to suppress the biting of the abrasive grains, and was broken in the side pressure rupture resistance test. Therefore, productivity was set to x. In addition, the thin conductive layer is No. In No. 21, the conductivity required for electrolytic plating was not obtained, and a plating layer could not be formed. Therefore, productivity was set to x.

  In addition, the thick resin No. Although 24 has sufficient strength, the wire diameter increases and the cutting margin increases, which is not preferable because the yield decreases. Similarly, from the viewpoint of cost, No. 2 where the conductive layer is thick. No. 25 is not preferable because the amount of metal used in the conductive layer is increased, leading to an increase in cost. In contrast, no. In 20, 22, and 23, the thicknesses of the resin layer and the conductive layer were optimum, and the productivity was good.

DESCRIPTION OF SYMBOLS 1 ......... Cutting device 3 ......... Ingot 5 ......... Holding part 7 ......... Wire saw 9 ......... Roller 11 ......... Core wire 13 ......... Resin layer 15 ...... Conductive layer 17 ......... Plating layer 19 ......... Abrasive grain 20 ......... Wire saw manufacturing device 21 ......... Fiber base material 23 ...... Heater 25 ......... Resin layer coating die 27 ...... UV irradiation device 29 ...... Resin layer coating die 31 ... …… Ultraviolet irradiation device 33 ............ Fiber bare wire 35 ............ Wire saw wire rod 37 ………… Winding device 40 ………… Wire saw manufacturing device 41 ………… Degreasing tank 43 ………… Washing tank 45 ………… Plating Tank 47... Washing tank 49... Cathode 51... Anode 53... Winding device 55... Metal plate 57 ... Diamond abrasive grain 60. Glass plate 63 ... …… Adhesive

Claims (5)

A core wire made of quartz fiber;
A resin layer formed on an outer periphery of the core wire and protecting the core wire;
A conductive layer formed on the outer periphery of the resin layer;
Comprising an abrasive-holding layer having a coating thickness thicker than the conductive layer formed by plating on the outer periphery of the conductive layer;
The elongation value of the resin of the resin layer is 5% or more, and the elastic modulus of the resin of the resin layer is 800 MPa or more,
Furthermore, the elongation of the resin of the resin layer covering the core wire / the elongation of the metal of the abrasive grain holding layer is 1.0 or more,
When the resin used for the resin layer is applied to the glass plate surface and the peeling force required for peeling the resin in a peel test is evaluated, the resin layer has an adhesion strength to glass of 2.0 N / mm or more. A wire rod for wire saw.   2. The wire saw wire according to claim 1, wherein the resin layer has a thickness of 10 to 30 μm, and the outermost abrasive grain holding layer is made of any metal of nickel, copper, and tin. The fine particles forming the conductive layer are conductive particles, the thickness of the conductive layer is 2 to 10 μm, and the volume resistivity of the conductive layer is in the range of 10 ⁻³ to 10 ^−6. The wire material for wire saws according to claim 1 or 2.   The wire material for a wire saw according to any one of claims 1 to 3, wherein the core wire has an outer diameter of 60 to 300 µm and a tensile strength of 5000 MPa or more. Using the wire material for a wire saw according to any one of claims 1 to 4,
The abrasive grain holding layer formed on the outer periphery of the conductive layer;
Abrasive grains held in the abrasive grain holding layer;
Comprising
The wire saw, wherein the abrasive grain holding layer is formed by plating.

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