JP2004050301A - Wire saw and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire saw having high working efficiency, being hardly broken, and having high producibility and to provide its manufacturing method. <P>SOLUTION: Abrasive grains 16 are fixed with a plating layer 18 and a resin layer 20 so as to have high abrasive grain holding force compared with a case of being fixed by the resin layer 20 alone. The resin layer 20 also contributes to the holding of the abrasive grains 16 so that the thickness of the plating layer necessary for obtaining a similar abrasive grain holding force or more to a case where the abrasive grains 16 are held by the plating layer 18 alone becomes thinner so as to relatively lower the elastic modulus. The elastic modulus of the resin layer 20 covering over the surface of the wire saw 10 is low compared with that of the plating layer 18 so as to suppress the whole elastic modulus low. This constitution can heighten the resistance against torsional rupture so as to suppress the breaking. The thickness of the plating covering over the surface of the abrasive grains 16 is thinned according to the thinning of the thickness of the plating layer 18 so as to improve the cutting performance of the wire saw 10. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a wire saw and a method for manufacturing the same.
[0002]
[Prior art]
For example, when manufacturing various semiconductor devices, for example, a columnar material ingot made of single crystal, polycrystal, or amorphous silicon, crystal, quartz, glass, or the like is formed into a thin plate (wafer) having a predetermined thickness by slicing. ). As a processing method for cutting such a highly brittle material with high accuracy and at a low price, use of a fixed abrasive type wire saw in which abrasive grains, for example, super abrasive grains such as diamond and cBN are fixed to the outer peripheral surface of the wire. Have been tried.
[0003]
[Problems to be solved by the invention]
Conventionally, cutting of a highly brittle material as described above has been performed with an inner peripheral blade having abrasive grains fixed to an inner peripheral portion or a wire saw using loose abrasive grains. The above-mentioned inner peripheral blade can obtain high machining efficiency because it is a fixed abrasive, but since the difference between the inner diameter and the inner and outer diameters needs to be larger than the ingot diameter, it is necessary to cope with an increase in the diameter of the ingot. Is difficult. Further, even if a large number of thin plates are cut out at the same time using a large number of tools, it is difficult to realize a multi-saw due to the structure for supporting the outer periphery. On the other hand, a wire saw using loose abrasives can easily cope with a large diameter ingot, and a multi-saw can be easily realized by winding a large number of wires between multi-groove pulleys. There is a problem that the efficiency is low, and a large amount of grinding oil waste liquid containing abrasive grains and cuttings of a workpiece is generated, resulting in a high environmental load. In addition, in the case of a large-diameter ingot, the supply of loose abrasive grains becomes more difficult toward the inner peripheral side, so that there is a problem that the processing efficiency is further reduced. The fixed abrasive type wire saw combines the advantages of the inner peripheral blade where the abrasive grains are fixed to the tool and the advantages of the loose abrasive type wire saw which is processed using a wire, and has a high cutting efficiency. It has the advantage that it can be cut even with a large-diameter ingot, and it can be suitably used for cutting a workpiece requiring precise and low damage or a difficult-to-cut material such as sapphire. Another feature is that the abrasive grain size can be increased relative to the wire diameter of the wire as compared with the case of loose abrasive grains.
[0004]
By the way, fixed abrasive type wire saws are classified into electrodeposited wire saws in which abrasive grains are fixed by metal plating and resin wire saws in which abrasive grains are fixed by resin, according to the method of fixing the abrasive grains. The former electrodeposited wire saw has a high abrasive holding power, so abrasive grains are less likely to fall off compared to resin wire saws and can maintain a high processing efficiency for a long period of time. Since the electrodeposition (plating) speed of the abrasive grains is low, there is a problem of low production efficiency. Incidentally, in the cutting process using a wire saw, for example, a wire having a length of at least several tens to 100 (km) is required for one ingot, for example, and therefore it is desirable that the tool manufacturing efficiency be as high as possible. It is. Further, in order to reliably hold the abrasive grains, the plating thickness needs to be set to a sufficient thickness dimension of, for example, 50% or more of the abrasive grain size, desirably about 60 to 70%. Accordingly, the elastic modulus of the entire wire saw is increased, so that the wire saw is weak against torsion, and there is also a disadvantage that the wire is easily broken during use. In addition, resin wire saws have relatively high manufacturing efficiency and have a strong advantage against torsion because of their low modulus of elasticity. There is an inconvenience that the processing efficiency is apt to be reduced if it falls off.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wire saw having high processing efficiency, hardly breaking wires, and high manufacturing efficiency, and a method for manufacturing the same.
[0006]
[First means for solving the problem]
In order to achieve such an object, the gist of the first invention is a wire saw in which abrasive grains are fixed to an outer peripheral surface of a wire, and (a) a plating layer covering the outer peripheral surface of the wire; b) a resin layer covering the plating layer, wherein the abrasive grains are fixed by the plating layer and the resin layer.
[0007]
[Effect of the first invention]
In this case, the abrasive grains are fixed to the outer peripheral surface of the wire by the plating layer and the resin layer provided on the outer peripheral surface of the wire. For this reason, based on the abrasive grain fixing force of the underlying plating, a high abrasive grain holding force is obtained as compared with a case where the resin is fixed only with the resin, so that the dropping of the abrasive grains is suitably suppressed and a high processing efficiency is obtained. Can be. In addition, since the resin contributes to the holding of the abrasive grains in addition to the plating, the plating layer thickness required to obtain the abrasive holding power equal to or higher than that of the conventional electrodeposited wire saw becomes thin, so the wire by the plating is used. The increase in the elastic modulus of the saw is suppressed. Further, since the elastic modulus of the resin covering the surface is lower than that of the plating, the elastic modulus of the entire wire saw can be kept lower. Therefore, resistance to destruction due to torsion is increased, and disconnection is suppressed. In addition, in the case of electrodeposition, the abrasive grains themselves are also covered by the plating layer. However, the thinning of the plating covering the surface of the abrasive grains improves the sharpness of the wire saw, so that the processing efficiency is further enhanced. Furthermore, since the required plating thickness is reduced, the time required for electrodeposition of the abrasive grains is shortened, so that the production efficiency is improved. As described above, a wire saw having high processing efficiency, hardly breaking wires, and high manufacturing efficiency can be obtained.
[0008]
According to the present invention, the cross-sectional area is increased by the thickness of the resin layer within the range of the wire diameter allowed according to the cutting processing conditions. Therefore, in order to increase the production efficiency of the wire saw or to keep the elastic modulus as low as possible, the thickness of the plating layer has been extended and the wire diameter has been kept at a value lower than the allowable wire diameter determined according to the cutting allowance and the like. In such an application, there is an advantage that the torsional stress for the same torsional moment is reduced. That is, according to the present invention, even if the thickness of the entire coating is increased by increasing the thickness of the resin layer, the elastic modulus of the entire wire saw is kept low and the decrease in the production speed is small. Therefore, the cross-sectional area can be increased.
[0009]
[Other aspects of the first invention]
Here, preferably, the wire saw includes a metal layer that covers an outer peripheral surface of the abrasive grains. With this configuration, the metal layer on the surface of the abrasive grains and the plating layer are chemically bonded (metal-bonded), so that a sufficient abrasive grain holding force can be obtained with a thinner plating thickness. Therefore, there is an advantage that the resistance to twisting is further increased and the manufacturing efficiency is further increased.
[0010]
That is, the abrasive grains may be coated with a metal layer, or may be bare without any coating. In the case of the former, the advantage that the abrasive grain holding power is increased becomes remarkable. On the other hand, in the latter case, the effect of the resin layer that suppresses the elution of metal of the plating layer during the cutting of the workpiece becomes significant.
[0011]
Preferably, the metal layer is made of nickel. In this case, since nickel is a ferromagnetic material, there is an advantage that abrasive grains can be easily attached to the wire using a magnetic force.
[0012]
Preferably, the plating layer and the metal layer are made of nickel. In this case, in addition to the advantage that the abrasive grains can be attached to the wire by magnetic force, the metal layer and the plating layer, both of which are made of nickel, are strongly chemically bonded to each other, so that the plating layer is made thinner. However, there is an advantage that a sufficient abrasive holding force can be obtained. In addition, since the plating layer and the metal layer are both made of nickel, even if the components of the metal layer covering the abrasive grains elute when the abrasive grains are supplied into the electrodeposition solution, the quality of the plating is improved. There is also an advantage that impurities that affect the mist are not mixed into the electrodeposition liquid.
[0013]
Preferably, the abrasive has an average particle diameter in the range of 1 to 60 (μm). In this case, since the abrasive grain size is sufficiently small, the abrasive grains hardly fall off, so that higher working efficiency can be obtained. If the average particle size is less than 1 (μm), the abrasive grains are too small, and the working efficiency is rather reduced. On the other hand, if it exceeds 60 (μm), the abrasive grains tend to fall off. More preferably, the lower limit of the average grain size of the abrasive grains is 2 (μm) or more, more preferably 3 (μm) or more, and the upper limit is 50 (μm) or less. The average grain size of the abrasive grains is preferably, for example, about 35% or less of the wire diameter.
[0014]
Preferably, in the wire saw, a coverage of the outer peripheral surface of the wire with the abrasive grains is in a range of 1 to 35 (%). In this way, since the coverage is kept in a sufficiently small range, the elasticity of the wire saw is increased due to the abrasive grains being fixed, and the rigidity is prevented from increasing. Therefore, the shearing force generated when twisted during use is reduced, and disconnection is suppressed. In addition, since a space for cutting chips to escape is secured with a sufficient size, clogging is suppressed and processing is performed even in the case of a material such as glass or crystal that is easily clogged (so-called “sticky”). Efficiency is further enhanced. The coverage is more preferably in the range of 1 to 25 (%), more preferably in the range of 5 to 25 (%).
[0015]
Preferably, the wire saw has a high-density region where the coverage of the abrasive grains is relatively high and a low-density region where the coverage is relatively low alternately in the longitudinal direction of the wire. More preferably, in the high-density region, the abrasive grains are fixed at a coverage within a range of 1 to 35 (%), and in the low-density region, the abrasive particles are 0.2 to 28 (%). ) Is fixed at a coverage within the range of (1).
[0016]
Preferably, the resin layer contains a filler made of an inorganic material. By doing so, there is an advantage that the thermal conductivity of the resin layer is increased and the wear resistance is enhanced. The filler is preferably aluminum oxide.
[0017]
Preferably, the embedding rate of the abrasive grains, that is, the ratio of the total thickness dimension of the plating layer and the resin layer to the delivery dimension of the abrasive grains in the radial direction of the wire is in the range of 20 to 90 (%). is there. More preferably, the embedding rate is in the range of 25 to 80 (%), more preferably in the range of 30 to 70 (%). With this configuration, since the abrasive grains are securely held and a part of the abrasive grains is appropriately exposed, the falling off of the abrasive grains is appropriately suppressed, and good sharpness is obtained.
[0018]
[Second means for solving the problem]
The gist of the second invention for achieving the above object is a method for manufacturing a wire saw in which abrasive grains are fixed to an outer peripheral surface of a wire, wherein (a) the wire is placed in an electrodeposition liquid. An abrasive grain electrodeposition step of attaching and electrodepositing abrasive grains on the outer peripheral surface thereof while moving, and (b) a resin coating step of coating the wire on which the abrasive grains are electrodeposited with a resin. .
[0019]
[Effect of the second invention]
With this configuration, since the outer peripheral surface of the wire to which the abrasive grains are fixed by electrodeposition is covered with the resin, the abrasive grains are covered by the plating layer and the resin layer provided on the outer peripheral surface of the wire. Is fixed to. For this reason, based on the abrasive grain fixing force of the underlying plating, a high abrasive grain holding force is obtained as compared with a case where the resin is fixed only with the resin, so that the dropping of the abrasive grains is suitably suppressed and a high processing efficiency is obtained. Can be. In addition, since the resin contributes to the holding of the abrasive grains in addition to the plating, the plating layer thickness required to obtain the abrasive holding power equal to or higher than that of the conventional electrodeposited wire saw becomes thin, so the wire by the plating is used. Since the increase in the elastic modulus of the saw is suppressed and the resin covering the surface has a lower elastic modulus than plating, the resistance to breaking due to torsion is increased, and disconnection is suppressed. In addition, since the sharpness of the wire saw is improved by reducing the plating thickness covering the surface of the abrasive grains, the processing efficiency is further improved. Furthermore, since the required plating thickness is reduced, the time required for electrodeposition of the abrasive grains is shortened, so that the production efficiency is improved. As described above, a wire saw having high processing efficiency, hardly breaking wires, and high manufacturing efficiency can be obtained.
[0020]
[Another aspect of the second invention]
Here, preferably, the abrasive grain electrodeposition step is to supply a predetermined amount of the abrasive grains from above to the wire being moved in the electrodeposition liquid. In this way, since the abrasive particles are attached to the outer peripheral surface of the wire with a distribution according to the supply amount of the abrasive particles and the dispersion state at the time of supply, the desired concentration can be achieved by appropriately controlling the supply amount. A wire saw having a certain degree or a desired abrasive grain density distribution is obtained. That is, the electrodeposition liquid may be a liquid in which abrasive grains are dispersed in advance, or may be a liquid to which a required amount of abrasive grains is sequentially supplied. The supply of the abrasive grains may be performed from above the liquid surface of the electrodeposition liquid, or may be performed from below the liquid surface. Incidentally, it was difficult to reduce the amount of abrasive grains with a conventional wire saw, which also contributed to an increase in the elastic modulus. Since it is easy to reduce the amount, an increase in the elastic modulus of the wire saw can be suitably suppressed. In addition, according to the above-mentioned abrasive grain supply method, since the coverage of the outer peripheral surface of the wire with the abrasive grains is at most about 50 (%), there is an advantage that a wire saw having an appropriately coarse abrasive grain density can be easily obtained. is there.
[0021]
Moreover, when the abrasive grains are supplied from above as described above, plating (electrodeposition) is performed with the abrasive grains on the outer peripheral surface of the wire in a thickness of about one or two or three layers. Since metal ions are quickly supplied in the vicinity of the wire, there is an advantage that problems such as burning and hydrogen generation hardly occur even if the current density at the time of electrodeposition is increased. Therefore, the current density can be increased and the manufacturing efficiency can be further increased. In addition, since the thickness of the abrasive particles attached to the outer peripheral surface of the wire is reduced, plating inhibition by the abrasive particles is unlikely to occur, so that the current density can be increased even in a watt bath. Therefore, the production efficiency can be further improved, and the maintenance of the electrodeposition solution (plating bath) can be simplified, so that the production cost can be further reduced. Further, since full automation is facilitated, an extremely long wire saw can be used. It becomes easy to configure equipment that can be manufactured.
[0022]
Preferably, the abrasive grain electrodeposition step includes attaching the abrasive grains in a predetermined distribution to the outer peripheral surface of the wire by changing the abrasive grain density of the electrodeposition liquid in the vicinity of the wire with time. It is to let. In this way, a desired abrasive grain density distribution can be obtained according to the change over time of the abrasive grain density and the moving speed of the wire in the longitudinal direction. By the way, with the conventional wire saw, there is also a disadvantage that it is not possible to select an appropriate degree of concentration according to the type of the workpiece and the processing conditions.
[0023]
Preferably, the abrasive grains have an outer peripheral surface covered with a metal layer. In this way, in the abrasive grain electrodeposition step, a higher abrasive grain holding force is secured based on the chemical bond (metal bond) between the metal layer on the abrasive grain surface and the plating layer. In addition, since the abrasive grains coated with the metal layer are positively charged in the electrodeposition (plating) solution, if the wire is used as a cathode, an adsorption effect by electric force (Coulomb force) can be obtained. Therefore, even before the abrasive grain fixing action by plating is obtained, the abrasive grains adhered to the wire are unlikely to peel off, so that the feed rate of the wire in the electrodeposition liquid can be increased to further increase the production efficiency. In addition, since the metal layer also has conductivity, there is an advantage that the current density can be further increased.
[0024]
Preferably, the abrasive grain electrodeposition step includes a magnetizing step of magnetizing the wire, and an attaching step of attaching the abrasive grains to the magnetized wire by magnetic force. In this way, since the abrasive grains covered with the metal layer are magnetically attracted to the magnetized wire, the abrasive grains attached to the wire are peeled off even before the abrasive grain fixing action by plating is obtained. Since it is difficult, the feed rate of the wire in the electrodeposition liquid can be increased to further increase the production efficiency.
[0025]
Preferably, the metal layer is made of nickel. In this case, since nickel is a ferromagnetic material, there is an advantage that in the above-mentioned attaching step, abrasive grains can be easily attached to the wire by using a magnetic force.
[0026]
Preferably, the metal layer is made of nickel, and the abrasive grain electrodeposition step is to electrodeposit the abrasive grains on the wire by nickel plating. In this case, in addition to the advantage that the abrasive grains can be attached to the wire by magnetic force, the metal layer and the plating layer, both of which are made of nickel, are strongly chemically bonded to each other, so that the plating layer is made thinner. However, there is an advantage that a sufficient abrasive holding force can be obtained.
[0027]
Preferably, the resin coating step includes a resin solution adhering step of adhering the resin solution to an outer peripheral surface thereof while moving the wire in the resin solution, and a resin solution adhering to the outer peripheral surface. And a resin film forming step of forming a film. By doing so, the abrasive grains held on the outer peripheral surface of the wire by electrodeposition are covered with the resin, and the abrasive grains are suitably held by the plating layer and the resin layer.
[0028]
Preferably, the abrasive has an average particle diameter in the range of 1 to 60 (μm). In this case, since the abrasive particle size is sufficiently small, it becomes easier to attach the abrasive particles to the outer peripheral surface of the wire by electric force or magnetic force. If the average particle size is less than 1 (μm), the abrasive grains are too small, and the working efficiency is rather reduced. On the other hand, if it exceeds 60 (μm), it becomes difficult to disperse in the electrodeposition solution, it becomes difficult to adhere by magnetic force, and the abrasive grains easily fall off even after the production.
[0029]
Further, preferably, the abrasive grain electrodeposition step comprises: a first electrodeposition step of electrodepositing the abrasive grains on an outer peripheral surface thereof while moving the wire in the electrodeposition liquid in a first direction in a circumferential direction thereof. And a second electrodeposition step of electrodepositing the abrasive grains on the outer peripheral surface while moving through the electrodeposition liquid in a second direction whose direction in the circumferential direction is reversed. In this case, since the wire is turned upside down and the abrasive grains are electrodeposited in each direction, there is an advantage that the abrasive grains can be electrodeposited with a uniform distribution in the circumferential direction. In general, as the average grain size of the abrasive grains increases, for example, when it exceeds about 35 (μm), it becomes difficult to attach the abrasive grains to the entire circumference of the wire only by electric or magnetic action. In such a case, the effect of reversing the wire is remarkably obtained.
[0030]
In the case where the wire is reversed and the abrasive grains are electrodeposited as described above, the plating layer on the side where the abrasive grains have been electrodeposited may be thicker. If a countermeasure such as shielding the wire during the liquid contact is taken, there is no particular problem since the entire periphery can be plated uniformly. Further, the first electrodeposition step and the second electrodeposition step may be performed in the same tank, or may be performed in separate tanks.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0032]
FIG. 1 is a perspective view showing a part of the fixed abrasive grain wire saw 10 according to one embodiment of the present invention in the longitudinal direction, and FIG. 2A is a view showing a cross section perpendicular to the longitudinal direction. is there. In these figures, a wire saw 10 has a large number of abrasive grains 16 fixed to an outer peripheral surface 14 of a wire 12, and the outer peripheral surface 14 has a plating layer 18 and a resin layer 20 in order from the inner peripheral side. Is provided. The abrasive grains 16 are partly embedded in the plating layer 18 and most of the remaining part is embedded in the resin layer 20, and are held by the plating layer 18 and the resin layer 20. A part thereof protrudes on the layer 20 to form a cutting edge.
[0033]
The wire 12 is made of, for example, a steel wire such as a piano wire, and has a wire diameter of, for example, about 0.05 to 0.30 (mm), for example, about 0.16 (mm). The abrasive grains 16 are single crystal diamond abrasive grains having an average particle size of, for example, about 1 to 80 (μm), for example, about 15 (μm), and the surface thereof is a metal layer made of nickel or the like. 22. The metal layer 22 is provided by, for example, plating or a CVD method, and has a thickness of, for example, about 0.1 to 10 (μm), for example, about 1 (μm). Therefore, the average grain size of the abrasive grains 16 including the metal layer 22 covering the surface is, for example, about 17 (μm).
[0034]
The plating layer 18 is made of, for example, nickel or the like, and covers the outer peripheral surface 14 of the wire 12 with a substantially uniform thickness within a range of, for example, 0.5 to 10 (μm), for example, about 4 (μm). Things. The resin layer 20 is made of a resin having, for example, an elasticity of about 1.8 (GPa) and an elongation of about 5 (%), for example, in a range of about 0.5 to 15 (μm). For example, it is provided with a thickness of about 6 (μm). Therefore, the ratio of the total value of the plating layer thickness and the resin layer thickness to the embedding rate of the abrasive grains 16, that is, the abrasive grain size is about 60 (%). That is, about 40% of the abrasive grains 16 protrude from the surface of the resin layer 20. In this embodiment, both the plating layer 18 and the resin layer 20 are provided as an abrasive grain holding layer for holding the abrasive grains 16, and the thickness of the plating layer 18 is extremely small with respect to the abrasive grain size. The value is, for example, about 10 (%), but the total thickness dimension with the resin layer 20 is a value of 50 (%) or more of the particle size sufficient for holding the abrasive grains.
[0035]
The resin is, for example, a photo-curable acrylic resin cured by ultraviolet irradiation. Further, in the resin layer 20, a filler 24 is dispersed as shown in FIG. The filler 24 is, for example, fine ceramic particles such as alumina or silica having an average particle diameter of about 0.5 to 10 (μm), for the purpose of increasing the thermal conductivity and abrasion resistance of the resin layer 20. , In a volume ratio of about 3 to 50 (%).
[0036]
Further, as shown in FIG. 1, the abrasive grains 16 are provided on the outer peripheral surface 14 of the wire 12 with a relatively sparse distribution, and the abrasive grain coverage on the outer peripheral surface 14, that is, the The ratio of the area covered by the abrasive grains 16 is, for example, about 35 (%) or less. Further, the distribution of the abrasive grains is not uniform in the longitudinal direction of the wire 12, and relatively dense portions and relatively sparse portions are provided alternately. The coverage in the high density region is in the range of 1 to 35 (%), and the coverage in the low density region is in the range of 0.2 to 28 (%). In the figure, the abrasive grain distribution is drawn more sparsely than in actuality for convenience of explanation.
[0037]
In the wire saw 10 of the present embodiment configured as described above, since the abrasive grains 16 are fixed to the outer peripheral surface 14 of the wire by the plating layer 18 and the resin layer 20, the abrasive grains of the plating layer 18 serving as a base are formed. Based on the fixing force, a higher abrasive grain holding force can be obtained as compared with the case where the resin layer 20 is used to fix only the resin layer 20, so that the removal of the abrasive grains 16 can be suitably suppressed, and high processing efficiency can be obtained. Further, since the resin layer 20 in addition to the plating layer 18 contributes to holding the abrasive grains 16, an abrasive grain holding force equal to or higher than that of a conventional electrodeposited wire saw that holds the abrasive grains 16 only with the plating layer 18 is obtained. Therefore, the thickness of the plating layer required for this purpose is reduced, so that the elastic modulus is kept at a relatively low value. Further, since the elasticity of the resin layer 20 covering the surface of the wire saw 10 is lower than that of the plating layer 18, the overall elasticity can be kept lower. As a result, resistance to destruction due to torsion is increased, and disconnection is suppressed. In addition, since the plating thickness covering the surface of the abrasive grains 16 is reduced as the thickness of the plating layer 18 is reduced, the sharpness of the wire saw 10 is also improved. Therefore, the wire saw 10 having high processing efficiency and hardly breaking can be obtained.
[0038]
In addition, the conventional electrodeposited wire saw requires a long time for electrodeposition, so that the thickness of the plating layer is limited to about 40% of the average grain size of the abrasive grains 16, so that the entire wire saw is Although the cross-sectional area was relatively small, according to the present embodiment, the thickness of the plating layer 18 was made thinner than the conventional one, but the total thickness with the resin layer 20 was the average of the abrasive grains 16. Since the particle size is set to a large value of about 60 (%), the cross-sectional area of the wire saw 10 is larger than in the related art. For this reason, the torsional stress for the same torsional moment is reduced, which also makes it harder for the disconnection to occur as compared with the related art.
[0039]
Further, in this embodiment, since the abrasive grains 16 are covered with the metal layer 22, the metal layer 22 and the plating layer 18 are metal-bonded, so that the plating tank 18 is as thin as about 2 (μm). However, there is an advantage that a sufficiently high abrasive grain holding force can be obtained. Particularly, in this embodiment, since both the plating layer 18 and the metal layer 22 are made of nickel, there is an advantage that a higher bonding force can be obtained between them.
[0040]
Further, in this embodiment, since the average grain size of the abrasive grains 16 is about 15 (μm), there is an advantage that the abrasive grains 16 are hard to fall off during machining and a high machining efficiency can be obtained.
[0041]
Further, in this embodiment, since the coverage by the abrasive grains 16 is kept at 35 (%) or less, the elasticity of the wire saw 10 is kept at a low value, and disconnection due to torsional stress during use is prevented. In addition to being further suppressed, a space for cutting chips to escape is secured with a sufficient size, so that there is an advantage that clogging is suppressed and processing efficiency is further enhanced.
[0042]
Further, in the present embodiment, since the surface of the wire saw 10 is covered with the resin layer 20, when the wire saw is used by being wrapped around a pulley of the cutting apparatus, the contact with the pulley is softened. There is also an advantage that the pulley wear is suppressed as compared with the arrival wire saw.
[0043]
The wire saw 10 is manufactured by using, for example, a wire saw manufacturing apparatus 30 shown in FIG. In the figure, the manufacturing apparatus 30 is provided with a roll 32 serving as a supply source of the wire 12, and in order from the roll 32 side, a degreasing tank 34, a first washing tank 36, an pickling tank 38, and a second washing tank. 40, a base plating tank 42, an electrodeposition tank 44, and a third washing tank 46 are provided adjacent to each other, and a storage tank 48 is provided as a separate step. A plurality of pulleys (guide pulleys) 50 are provided inside and above the tanks 34 to 48, respectively, and the wire 12 is guided by the pulleys 50 to sequentially pass through the tanks 34 to 46. Is passed through. In addition, the inside of the storage tank 48 is, for example, taken out of the third washing tank 46 and once wound up, and then passed again.
[0044]
The degreasing tank 34 stores, for example, an aqueous solution of sodium hydroxide (NaOH), and dirt such as oil adhering to the surface of the wire 12 is removed here. The first washing tank 36 is for washing away the aqueous sodium hydroxide solution adhering to the wire 12 from which oil has been removed. The pickling tank 38 stores, for example, hydrochloric acid (HCl aqueous solution), and an oxide layer (rust) on the surface of the wire 12 is removed here. The second washing layer 40 is for washing away the hydrochloric acid adhered here.
[0045]
The undercoating tank 42 is for applying, for example, brass (brass) plating as an undercoating so that nickel plating can be easily applied to the wire 12, and an electrodeposition solution containing copper ions and zinc ions in the tank. (Plating solution) is stored. In FIG. 2, the brass plating layer is omitted. The electrodeposition tank 44 is for fixing (electrodepositing) the abrasive grains 16 to the wire 12 provided with the base plating by nickel plating, and an electrodeposition liquid containing nickel ions is stored in the tank. The length of the wire 12 in the moving direction is, for example, about 1 (m). The electrodeposition solution or plating bath in the electrodeposition bath 44 is a watt bath composed of nickel sulfate, nickel chloride, and boric acid, and is adjusted to, for example, a pH in a range of about 3.0 to 6.0. The temperature of the plating bath is, for example, in a range of about 30 to 50 (° C.). In the traveling path of the wire 12, cathode electrodes 52 that are in contact with the wire 12 are provided at three places before and after the base plating tank 42 and the electrodeposition tank 44, and are provided in the tanks 42 and 44. Current is supplied to the anode electrode. The current density is, for example, 0.5 to 30 (A / dm ² ) Is adjusted within the range.
[0046]
A magnet 54 is provided above the electrodeposition tank 44 near the base plating tank 42. The magnet 54 is a permanent magnet such as an alnico magnet or a rare earth magnet (eg, samarium cobalt), and the wire 12 is magnetized by the magnet 54 before entering the electrodeposition tank 44. Further, an abrasive sedimentation area 56 is provided in a part of the electrodeposition tank 44 on the side of the base plating tank 42, that is, on the rear side in the feed direction of the wire 12. In this abrasive grain sedimentation region 56, a plating solution in which the abrasive grains 16 are dispersed in a dispersion medium such as water is supplied toward the wires 12 in the electrodeposition liquid. The abrasive grains 16 contained in the plating solution are, for example, diamond abrasive grains (for example, IRM- manufactured by Tomei Diamond Co., Ltd.) in which the particle size is 15 (μm) and the metal layer 22 is provided with a thickness of about 1 (μm). NP30 M10 / 20). Here, an apparatus for supplying the plating solution, a recovery apparatus for recovering the settled surplus abrasive grains 16, and the like are appropriately provided. The third washing tank 46 is for washing the electrodeposition liquid from the wire 12 coming out of the electrodeposition tank 44.
[0047]
The storage tank 48 is for providing a resin layer 20 that covers the surface of the plating layer 18 of the wire 12 to which the abrasive grains 16 are fixed by nickel plating, and a liquid resin is stored in the tank. Examples of the liquid resin include bisphenol AEO-modified diacrylate (for example, Aronix M210 manufactured by Toagosei Co., Ltd.), 2-hydroxy-3phenoxypropyl acrylate (for example, Aronix M5700 manufactured by Toagosei Co., Ltd.), and 2,2-dimethoxy-1 , 2-diphenylethan-1-one (eg, Irgacure 651 by Nagase & Co., Ltd.) is a photocurable resin mixed at a ratio of, for example, 90: 10: 1, and a filler 24 such as alumina contains about 10 (%) It is dispersed at a volume ratio.
[0048]
A die 58 and an ultraviolet irradiation device 60 are provided above the storage tank 48. The die 58 is for uniformizing the thickness of the liquid resin adhered on the wire 12 that has passed through the storage tank 48, and the ultraviolet irradiation device 60 is for irradiating the liquid resin with ultraviolet light to cure the liquid resin. is there.
[0049]
When manufacturing the wire saw 10 using such a manufacturing apparatus 30, first, in the plating step (abrasive electrodeposition step), the inside of the degreasing tank 34 to the third washing tank 46 is sequentially guided by the pulley 50. Is wound by a suitable winding device such as a motor provided at the end of the third washing tank 46, so that the wire 12 is continuously moved at a constant speed in the direction of arrow R1. The wire feed speed is set to, for example, about 50 to 5000 (mm / min). In this movement process, after the oil film, oxides and the like on the wire outer peripheral surface 14 are removed in the degreasing tank 34 to the second washing tank 40, first, the wire 12 is subjected to brass plating in the base plating tank 42. The plating thickness is, for example, about 1 to 10 (μm). The wire 12 that has passed through the base plating tank 42 is magnetized by the magnet 54 and then enters the electrodeposition tank 44. In the present embodiment, this step corresponds to the magnetization step.
[0050]
In the electrodeposition bath 44, a plating solution containing the abrasive 16 is supplied from above to the wire 12 in the abrasive sedimentation region 56, so that the cathode 12 is brought into contact with the plating solution containing the abrasive 12. The abrasive grains 16 that settle in a dispersed state are adhered to the outer peripheral surface 14 of the substrate, and metal ions (nickel ions) in the electrodeposition liquid are attracted to the outer peripheral surface to form a plating layer 18. As a result, the abrasive grains 16 are fixed to the wire outer peripheral surface 14 by nickel plating (plating layer 18). At this time, the abrasive grains 16 are positively charged because the metal layer 22 is provided, so the abrasive grains 16 themselves are also electrically attracted to the wire 12. In addition, since the wire 12 is magnetized before entering the electrodeposition tank 44, the abrasive grains 16 covered with the metal layer 22 made of ferromagnetic nickel are magnetically attracted to the wire 12. Despite being attached to the wire 12 during the sedimentation process, it is also attached to a portion of the outer peripheral surface 14 located below the vertical direction. Therefore, by these electric and magnetic actions, the abrasive grains 16 are uniformly distributed over the entire length of the outer peripheral surface 14 of the wire 12 in the circumferential direction, and fall off until the fixing force by plating is exerted. Is suitably suppressed. In addition, since the abrasive grains 16 are attached to the wire 12 only during the sedimentation process, the thickness of the abrasive grains 16 attached to the outer peripheral surface 14 is only about one thickness of the abrasive grains 16.
[0051]
Since the abrasive sedimentation area 56 is provided in a part of the electrodeposition tank 44 on the rear side in the traveling direction of the wire 12, the wire 12 is attached to the outer peripheral surface 14 thereof in the electrodeposition tank 44. 16 is moved in the horizontal direction while being attached. In the present embodiment, the nickel plating is applied to the wire 12 in the process in which the abrasive grains 16 are moved with the abrasive grains 16 placed thereon, so that the abrasive grains 16 are fixed. For example, the current density in the electrodeposition tank 44 is set to 20 (A / dm. ² ) (That is, the plating speed is about 4 (μm / min)) and the feed speed of the wire 12 is about 1 (m / min), the length of the electrodeposition tank 44 is 1 (m) as described above. Therefore, a plating thickness of 4 (μm) can be obtained. The plating thickness is such that the diamond abrasive grains 16 having a particle size of about 15 (μm) and a thickness dimension of the metal layer 22 of about 1 (μm) are reliably electrodeposited as described above. Since the wire 12 and the abrasive grains 16 covered with the metal layer 22 are chemically bonded by nickel plating, a sufficient abrasive grain holding force can be obtained even with a small plating thickness. In the present embodiment, the step of passing through the abrasive sedimentation area 56 corresponds to the attaching step.
[0052]
The fixed density, that is, the distribution of the abrasive grains 16 on the wire 12 is determined by the supply amount of the abrasive grains 16 (plating solution) in the abrasive grain sedimentation region 56. Therefore, when manufacturing the wire saw 10 in which the high-density regions and the low-density regions are alternately provided in the longitudinal direction of the wire 12 as described above, the amount of abrasive particles to be supplied is related to the moving speed of the wire 12. (Amount of plating solution or concentration of abrasive grains in plating solution) may be changed with time.
[0053]
After the wire 12 that has passed through the electrodeposition tank 44 as described above is washed and removed from the electrodeposition liquid in the third washing tank 46, the wire 12 is wound around a roll similar to the roll 32 and collected. The plated wire 12 is stored in this state until it is sent to the resin coating step. For example, by drying during storage, the water attached to the third washing tank 46 is removed. It may be wound through a roll while drying through a dryer following the washing tank 46.
[0054]
In the resin coating step performed after the abrasive electrodeposition step, the plated wire 12 is passed through the storage tank 48 while being rewound from the roll, and is appropriately wound by a motor or the like provided at the tip of the ultraviolet irradiation device 60. By taking up with a take-up device, it is continuously moved in the direction of arrow R2 at a constant speed. The wire feed speed at this time is set higher than that in the abrasive electrodeposition step, for example. In this process, the plating layer 18 is covered with the liquid resin in a non-uniform thickness, but is adjusted to a uniform thickness in accordance with the inner diameter by passing the die 58 out of the storage tank 48 and passing the die 58. . In the present embodiment, the step of passing through the storage tank 48 or the step of adjusting the adhesion thickness with the storage tank 48 corresponds to the resin solution adhesion step. The wire 12 that has passed through the die 58 is passed through an ultraviolet irradiation device 60 provided subsequently, and is irradiated with ultraviolet light in the process. As a result, the liquid resin, which is a photocurable resin, is cured, and the resin layer 20 is generated. In the present embodiment, the step of irradiating the ultraviolet rays corresponds to the resin film forming step. The wire saw 10 is manufactured in this manner.
[0055]
In this embodiment, as described above, the abrasive electrodeposition step through the degreasing tank 34 to the third washing tank 46 and the resin coating step through the storage tank 48 to the ultraviolet irradiation device 60 are performed. It will be implemented separately. Immediately after leaving the third washing tank 46, the liquid resin is hard to adhere because the wire 12 is wet, but since the plated wire 12 is passed through the storage tank 48 in a sufficiently dried state, its outer periphery is The liquid resin can be reliably attached to the surface. In addition, since the resin coating process that can easily increase the wire feed speed is performed separately from the abrasive grain electrodeposition process, the wire 12 is fed at a high speed in the resin coating process, and the required time is extended, and the required time of the entire process is increased. The time can be shortened.
[0056]
Here, in the present embodiment, the outer peripheral surface 14 of the wire 12 on which the abrasive grains 16 are electrodeposited is covered with the resin layer 20, so that the abrasive grains 16 are coated on the outer peripheral face 14 by the plating layer 18 and the resin layer 20. It is fixed. Therefore, in addition to the plating layer 18, the resin layer 20 contributes to the holding of the abrasive grains 16, and the thickness of the plating layer 18 required to obtain a desired abrasive grain holding force is reduced. The time required for wearing is reduced. Therefore, there is an advantage that manufacturing efficiency can be improved.
[0057]
Moreover, in the present embodiment, a predetermined amount of abrasive grains 16 is supplied from above to the wire 12 being moved in the electrodeposition liquid, so that the outer peripheral surface 14 of the wire 12 depends on the supply amount. The abrasive grains 16 are attached with a thickness of about one layer with such a distribution. Therefore, the wire saw 10 having a desired concentration degree or a desired abrasive grain density distribution can be obtained by appropriately controlling the supply amount.
[0058]
Further, in the present embodiment, since the magnetic action in which the abrasive grains 16 covered with the metal layer 22 made of nickel are attracted to the magnetized wire 12 by magnetic force is also used, the abrasive grain fixing action by plating is not used. Even before being obtained, the abrasive grains 16 attached to the wire 12 are unlikely to peel off, so the feed rate of the wire 12 in the electrodeposition liquid is increased to 1 (m / min) or more as described above to further increase the production efficiency. There are advantages that can be.
[0059]
Next, another embodiment of the present invention will be described. Note that, in the following embodiments, description of portions common to the above-described embodiments will be omitted.
[0060]
The wire saw manufacturing apparatus 62 shown in FIG. 4 is configured substantially in the same manner as the above-described manufacturing apparatus 30, except that a second electrodeposition tank 64 is provided between the electrodeposition tank 44 and the third washing layer 46. Is different. Further, no magnet 54 is provided on the electrodeposition tank 44.
[0061]
When the plating layer 18 is formed by such a manufacturing apparatus 62 and the abrasive grains 16 are electrodeposited, since the wire 12 is not magnetized before entering the electrodeposition bath 44, the magnetic action in the above-described embodiment is not I can't get it. Therefore, the abrasive grains 16 settled on the wire 12 in the abrasive settling area 56 are attached to a substantially half-circumferential portion of the wire 12 located exclusively on the upper side and fixed by the plating layer 18, but are fixed on the lower side It is hardly adhered to the located part.
[0062]
The portion of the wire 12 that has passed through the electrodeposition tank 44 is turned upside down in the process of being guided by the pulley 50, and then passes through the second electrodeposition tank 64. The second electrodeposition tank 64 is also provided with an abrasive sedimentation region 56 on the rear side in the moving direction of the wire 12, and the abrasive particles 16 sedimenting from above while passing through the tank are covered with the outer peripheral surface 14. Of the electrodeposition tank 44, that is, on the side opposite to the half-circumferential portion of the electrodeposition tank 44, and is fixed by the plating layer 18. That is, in the present embodiment, the plating layer 18 is formed twice in the two electrodeposition tanks 44 and the second electrodeposition tank 64. As described above, even if the process for providing the plating layer 18 is performed twice by turning the wire 12 upside down instead of providing the magnetizing step, a wire saw similar to the wire saw 10 described above is obtained. be able to.
[0063]
When the nickel plating process is performed twice as described above, the plating thickness tends to be thicker in the half-peripheral portion where the abrasive grains 16 are fixed in the first plating process than in the remaining half-peripheral portion. When the difference in the thickness dimension causes a problem in processing performance, for example, by providing a shield or the like for covering the lower half of the wire 12 in the second electrodeposition tank 64, the difference in plating thickness is reduced. be able to.
[0064]
FIG. 5 is a diagram illustrating a cross section of a main part of a wire saw 66 according to another embodiment, and is a diagram corresponding to FIG. 2B. In this embodiment, the abrasive 16 is not covered with the metal layer 22, but the other components are the same as those of the wire saw 10. Also in such a wire saw 10, since the abrasive grains 16 are fixed by the laminated plating layer 18 and the resin layer 20, the required abrasive grain holding force is secured while reducing the thickness of the plating layer 18. That is, the same effect as in the above-described embodiment can be obtained.
[0065]
Moreover, in the present embodiment, since the metal layer 22 is not provided on the abrasive grains 16, the plating layer 18 is covered with the resin tank 20 so that the metal is not exposed on the surface of the wire saw 66. . For this reason, the metal constituting the plating layer 18 does not elute during the use of the wire saw 66. For example, when a material such as silicon that is not preferably contaminated by metal is cut, the contamination can be advantageously suppressed. That is, in the above-described wire saw 10, substantially the same effect can be obtained by covering the plating layer 18 with the resin layer 20, but the effect is more remarkable because the metal layer 22 covering the abrasive grains 16 does not exist. become.
[0066]
As described above, the present invention has been described in detail with reference to the drawings. However, the present invention can be implemented in other embodiments.
[0067]
For example, in the embodiment, when the abrasive grains 16 are fixed to the wire 12 in the electrodeposition bath 44, the supply amount is changed with time to form the abrasive grain density distribution in the longitudinal direction of the wire 12. However, it is also possible to manufacture the wire saw 10 in which the abrasive particles 16 are uniformly distributed while the supply amount is constant.
[0068]
In the embodiment, 20 (A / dm ² Although the plating process has been performed at a current density of about), the current density is appropriately changed according to a desired plating speed, abrasive grain density, and the like. When the plating rate is increased by increasing the current density, the thickness of the plating layer 18 formed on the abrasive grains 16 also increases, and the sharpness decreases. Therefore, the current density is preferably determined in consideration of the plating thickness on the abrasive grains 16.
[0069]
Further, in the embodiment, the case where the abrasive grains 16 are diamond is described, but the material of the abrasive grains 16 is appropriately selected according to the cutting target. For example, the present invention is similarly applied to a wire saw using other super-abrasive grains such as cubic boron nitride (cBN) and ordinary abrasive grains such as alumina and silicon carbide.
[0070]
Further, in the embodiment, a thermosetting liquid resin mixed with bisphenol AEO-modified diacrylate or the like is used, but the kind of the resin is a desired elasticity, mechanical strength, hardness or heat resistance of the resin layer 20. It is appropriately selected according to the properties and the like. For example, a vinyl ester resin (for example, Lipoxy LC-800 manufactured by Showa Polymer Co., Ltd.) is also preferably used. Further, instead of the photocurable resin, a resin cured by another method such as a thermosetting resin or an anaerobic curable resin may be used.
[0071]
Further, in the embodiment, the wire feed speed is set to 1 (m / min), but the feed speed is set so that the plating layer 18 and the resin layer 20 having desired thickness dimensions can be obtained. It is determined appropriately according to the size of the plating tank and the like.
[0072]
Further, in the embodiment, the plating layer 18 and the metal layer 22 are both made of nickel, but may be made of another metal material such as a nickel alloy such as Ni-Co or copper. Further, the constituent materials of the two may be different from each other.
[0073]
Further, in the embodiment, the plating solution containing the abrasive grains 16 is supplied from above the wire 12 in the electrodeposition tank 44, but the electrodeposition solution in which the abrasive grains 16 are dispersed at an appropriate concentration in advance is electrodeposited. The electrodeposition liquid may be stored in the tank 44 and plated in the electrodeposition solution through the wire 12.
[0074]
Further, in the embodiment, after the abrasive grains 16 are electrodeposited on the outer peripheral surface 14 of the wire 12 in the electrodeposition tank 44 or the electrodeposition tank 44 and the second electrodeposition tank 64, the rinsing process is immediately performed in the third rinsing tank 46. However, if the plating thickness formed in the electrodeposition tank 44 or the like is insufficient, an embedding tank for increasing the plating thickness may be provided before the third washing tank 46. The embedding tank has the same configuration as the electrodeposition tank 44, for example.
[0075]
In the embodiment, the abrasive electrodeposition step and the resin coating step are configured to be performed discontinuously, but after passing through the third washing tank 46, the wire 12 is forcibly forced by a dryer or the like. When the wire 12 is immediately brought into a state in which the resin solution can be suitably adhered, for example, when the wire 12 is dried, the two steps are continuously performed without winding the wire 12 after passing through the third washing tank 46. Can also be configured.
[0076]
Although not specifically exemplified, the present invention can be variously modified without departing from the gist thereof.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a part of a wire saw according to an embodiment of the present invention.
FIG. 2A is a diagram illustrating a cross-sectional structure of the wire saw of FIG. 1, and FIG. 2B is a diagram illustrating a part of a surface layer thereof in an enlarged manner.
FIG. 3 is a schematic diagram illustrating a configuration of a manufacturing apparatus for manufacturing the wire saw of FIG.
FIG. 4 is a diagram illustrating another configuration example of a manufacturing apparatus for manufacturing the wire saw of FIG.
FIG. 5 is a view corresponding to FIG. 2B for explaining a cross section of a main part of a wire saw according to another embodiment of the present invention.
[Explanation of symbols]
10: Wire saw
12: Wire
16: abrasive
18: Plating layer
20: resin layer
22: metal layer

Claims (11)

A wire saw with abrasive grains fixed to the outer peripheral surface of the wire,
A plating layer covering the outer peripheral surface of the wire,
And a resin layer covering the plating layer, wherein the abrasive grains are fixed by the plating layer and the resin layer. The wire saw according to claim 1, further comprising a metal layer covering an outer peripheral surface of the abrasive. 3. The wire saw according to claim 1, wherein the plating layer and the metal layer are made of nickel. The wire saw according to any one of claims 1 to 3, wherein the abrasive has an average particle diameter in a range of 1 to 60 (μm). The wire saw according to any one of claims 1 to 4, wherein a coverage of the outer peripheral surface of the wire with the abrasive grains is in a range of 1 to 35 (%). A method for manufacturing a wire saw in which abrasive grains are fixed to an outer peripheral surface of a wire,
An abrasive grain electrodeposition step of attaching the abrasive grains to the outer peripheral surface thereof while moving the wire in the electrodeposition solution and electrodepositing the wire,
A resin coating step of coating the wire on which the abrasive grains have been electrodeposited with a resin. 7. The wire saw manufacturing method according to claim 6, wherein in the abrasive grain electrodeposition step, a predetermined amount of the abrasive grains is supplied from above to the wire being moved in the electrodeposition liquid. The abrasive grain electrodeposition step is to cause the abrasive grains to adhere to the outer peripheral surface of the wire in a predetermined distribution by changing the abrasive grain density of the electrodeposition liquid in the vicinity of the wire with time. The method for producing a wire saw according to claim 6 or 7. The method for manufacturing a wire saw according to any one of claims 6 to 8, wherein the abrasive has an outer peripheral surface covered with a metal layer. The abrasive electrodeposition step,
A magnetizing step of magnetizing the wire;
The method for manufacturing a wire saw according to claim 9, further comprising an attaching step of attaching the abrasive grains to the magnetized wire by magnetic force. The metal layer is made of nickel,
The method for manufacturing a wire saw according to claim 9 or 10, wherein the abrasive grain electrodeposition step is to electrodeposit the abrasive grains on the wire by nickel plating.

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