JP2010201541A - Diamond wire saw, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diamond wire saw offering good sharpness during use and hardly causing breaking of a wire due to its sufficient hardness, and to provide a method of manufacturing the diamond wire saw. <P>SOLUTION: The diamond wire saw 1 comprises a metal core wire 10 dispersedly holding diamond abrasive grains 30 and a plated layer 20 covering an entire outer surface thereof, wherein the plated layer 20 is a nickel-tungsten alloy including, for example, 1-60 wt.% of tungsten. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a diamond wire saw and a method for producing the diamond wire saw.

When manufacturing various types of semiconductor devices, for example, a columnar material ingot made of single crystal, polycrystal, amorphous silicon, crystal, or the like is cut into a thin plate (wafer) having a predetermined thickness by slicing. The As a processing method for cutting such highly brittle materials with high accuracy and low cost, it is attempted to use a fixed-abrasive wire saw in which superabrasive grains such as diamond are fixed to the outer peripheral surface of the wire. It has been.
As such a thing, there exists the following patent documents 1-4.
Patent Document 1 below is an invention relating to a wire saw and a method for manufacturing the same, and discloses a wire saw in which superabrasive grains are firmly fixed to a wire and do not fall off, and the thickness is constant and high cutting accuracy is obtained. Yes.
Patent Document 2 below is an invention relating to a method and apparatus for manufacturing a wire saw, and discloses an electrodeposited wire saw having a low-density abrasive grain distribution.
Patent Document 3 below is an invention related to a wire saw and a method for manufacturing the same, and discloses a wire saw that has high processing efficiency, is difficult to break, and has high manufacturing efficiency.
Patent Document 4 below is an invention relating to an electrodeposited wire tool and a method for producing the same, and discloses an electrodeposited wire tool having excellent sharpness.

JP-A-9-150314 Japanese Patent No. 4157724 JP 2004-50301 A JP 2006-181701 A

  However, the wire saws and electrodeposition wire tools shown in the above Patent Documents 1 to 4 do not have sufficient hardness because the metal for plating the wire is Ni, Cu, etc. There was a problem that it was easy to do.

  Accordingly, the present invention solves the above-mentioned conventional problems, and has a sufficient hardness so as to provide a diamond wire saw having good sharpness at the time of use and difficult to break, and a method for producing the diamond wire saw. To do.

  The diamond wire saw of the present invention is a diamond wire saw in which the entire outer surface of a metal core wire in which diamond abrasive grains are dispersed and held is coated with a plating layer, and the plating layer is a nickel alloy containing tungsten. Is the first feature.

  According to the first feature of the present invention, since the plating layer is a nickel alloy containing tungsten, it can have sufficient hardness as a diamond wire saw. Therefore, it is possible to obtain a diamond wire saw that has good sharpness during use and is difficult to break.

  In addition to the first feature of the present invention, the diamond wire saw of the present invention has a second feature that the nickel alloy contains 1 wt% to 60 wt% of tungsten.

  According to the second feature of the present invention, in addition to the function and effect of the first feature of the present invention, the nickel alloy has a structure containing 1 wt% to 60 wt% of tungsten. The plating layer which comprises can be made into a favorable membrane | film | coat.

  The method for producing a diamond wire saw according to the present invention is a method for producing a diamond wire saw in which diamond abrasive grains are dispersed and held on the outer surface of a metal core wire, wherein the metal core wire is melted with nickel and tungsten. A third feature is that it has a diamond abrasive electrodeposition process in which electrolytic plating is performed using a nickel-tungsten bath in which diamond abrasive grains are dispersed in a solution.

  According to the third aspect of the present invention, a diamond wire saw manufacturing method in which diamond abrasive grains are dispersed and held on the outer surface of a metal core wire, wherein the metal core wire is melted with nickel and tungsten. Since it has a structure including a diamond abrasive electrodeposition process in which electrolytic plating is performed using a nickel-tungsten bath in which diamond abrasive grains are dispersed in a solution, the diamond abrasive electrodeposition process is performed on the outer surface of the metal core wire. A plating layer made of a nickel alloy containing tungsten can be formed, and the diamond abrasive grains can be reliably dispersed and held on the outer surface of the metal core wire by the plating layer. Therefore, it can have sufficient hardness as a diamond wire saw. Therefore, it is possible to produce a diamond wire saw that has good sharpness and is not easily broken during use.

  In addition to the third feature of the present invention, the diamond wire saw manufacturing method of the present invention has a molar ratio of nickel to tungsten in the nickel-tungsten bath of 1: 9 to 9: 1. Is the fourth feature.

  According to the fourth aspect of the present invention, in addition to the function and effect of the third aspect of the present invention, the ratio of nickel to tungsten in the nickel-tungsten bath is in a molar ratio of 1: 9 to 9: 1. Therefore, a nickel-tungsten plating film capable of obtaining sufficient hardness can be stably obtained.

  In addition to the third or fourth feature of the present invention described above, the diamond wire saw manufacturing method of the present invention is characterized in that the diamond grain electrodeposition step is carried out at a bath temperature of 50 ° C to 75 ° C. It has the characteristics of

  According to the fifth aspect of the present invention, in addition to the function and effect of the third or fourth aspect of the present invention, the diamond abrasive electrodeposition step is performed at a bath temperature of 50 to 75 ° C Therefore, the internal stress in the plating film can be effectively reduced, and abnormal precipitation can be prevented. Therefore, it can be set as the manufacturing method of a diamond wire saw with good manufacturing efficiency.

  Moreover, in addition to any one of the third to fifth features of the present invention described above, the method for producing a diamond wire saw of the present invention includes a solution in a nickel-tungsten bath, diammonium hydrogen citrate, sodium formate, The sixth feature is that the aqueous solution is obtained by dissolving nickel sulfate and sodium tungstate.

  According to the sixth aspect of the present invention, in addition to the function and effect of any one of the third to fifth aspects of the present invention, the solution in the nickel-tungsten bath contains diammonium hydrogen citrate, formic acid Because it is an aqueous solution in which sodium, nickel sulfate, and sodium tungstate are dissolved, the plating bath is highly stable and has a long life, so that it is a method for producing a diamond wire saw with excellent productivity. be able to.

  According to the diamond wire saw of the present invention and the method for producing the diamond wire saw, the diamond wire saw having sufficient hardness and having good sharpness at the time of use and difficult to break, and the method for producing the diamond wire saw It can be.

It is a perspective view which shows a part of diamond wire saw which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the diamond wire saw which concerns on embodiment of this invention, (a) is the whole sectional view of the direction orthogonal to the axis | shaft of a diamond wire saw, (b) is the partial expanded sectional view of the direction orthogonal to the axis | shaft of a diamond wire saw. is there. It is a figure which simplifies and shows the manufacturing process of the diamond wire saw which concerns on embodiment of this invention. It is a figure which simplifies and shows the diamond abrasive grain electrodeposition process in the manufacturing process of the diamond wire saw which concerns on embodiment of this invention. It is a figure which shows the hardening change by the heat processing of nickel-tungsten alloy plating of 40 wt% of tungsten.

  With reference to the following drawings, a diamond wire saw according to an embodiment of the present invention and a method for producing the diamond wire saw will be described to provide an understanding of the present invention. However, the following description is an embodiment of the present invention, and does not limit the contents described in the claims.

  First, a diamond wire saw according to an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, a diamond wire saw 1 according to an embodiment of the present invention is a diamond wire in which diamond abrasive grains 30 are dispersed and held by a plating layer 20 that covers the entire outer surface of a metal core wire 10. It is a saw.

  The metal core wire 10 may be any metal wire as long as the outer surface 11 can be electroplated and has a certain strength. For example, a steel wire such as a piano wire, a tungsten wire, a molybdenum wire, or the like can be used.

  The diameter of the metal core wire 10 can be appropriately changed depending on the material and shape of the work material, but is preferably 0.05 mm to 0.30 mm.

  As shown in FIGS. 1 and 2, the plating layer 20 covers the outer surface 11 of the metal core wire 10 and disperses and holds the diamond abrasive grains 30 on the metal core wire 10.

  The plating layer 20 is made of a nickel alloy containing tungsten. By setting it as such a structure, compared with the case where the plating layer 20 is comprised only with nickel, while being able to raise the hardness of the diamond wire saw 1, corrosion resistance can be improved. Therefore, at the time of use, while being sharp, it can be set as the diamond wire saw 1 which is hard to be disconnected.

The tungsten concentration in the nickel alloy is desirably 1 wt% to 60 wt%. If the amount is less than 1 wt%, a solid solution effect cannot be obtained, and if it exceeds 60 wt%, a good film cannot be obtained.
Even more preferably, it is desirable to be 10 wt% to 40 wt%.

The thickness of the plating layer 20 is desirably 20% to 90% with respect to the passing dimension of the diamond abrasive grains 30 in the radial direction of the metal core wire 10.
Even more preferably, it is preferably 25% to 80%, and more preferably 30% to 70%.

  As shown in FIG. 2, the diamond abrasive grains 30 are coated abrasive grains in which an outer surface 31 is coated with a plating layer 32, and are embedded in the plating layer 20 that covers the outer surface of the metal core wire 10. The plating layer 20 is dispersed and held.

  The plating layer 32 is made of nickel. By adopting such a configuration, nickel has a chemical affinity with the metal core wire 10 such as a piano wire, and thus is not only physically held by the plating layer 20 with respect to the metal core wire 10. It can also be held chemically. Therefore, the diamond abrasive grains 30 can be firmly held on the outer surface of the metal core wire 10. Accordingly, the diamond abrasive grains 30 can be prevented from falling off during use. In addition, the diamond abrasive grains 30 can be dispersed and held on the metal core wire 10 with a small amount of the plating layer 20, and the diamond wire saw 1 with good manufacturing efficiency can be obtained.

The average grain size of the diamond abrasive grains 30 is desirably 1 μm to 60 μm. By setting it as such a structure, since the abrasive particle diameter is made small enough, the diamond abrasive grain 30 cannot fall easily from the metal core wire 10, and it can be set as the diamond wire saw 1 with sufficient work efficiency.
If the average particle size is less than 1 μm, the abrasive grains are too small, so that the processing efficiency is lowered.
More preferably, the lower limit is 2 μm or more, more preferably 3 μm or more, and the upper limit is preferably 50 μm or less.

Further, the coverage by the diamond abrasive grains 30 on the outer surface 11 of the metal core wire 10 is preferably 1% to 35%. By adopting such a configuration, the coverage rate can be kept in a sufficiently small range, and the elastic modulus of the diamond wire saw 1 is increased due to the dispersion and holding of the diamond abrasive grains 30. Increase in rigidity is suppressed.
In addition, since the space through which the chips escape is secured with a sufficient size, clogging is suppressed even in the case of a material that is likely to be clogged, such as glass or quartz, and the processing efficiency is further improved.
The coverage is more preferably 1% to 25%, and further preferably 5% to 25%.

In the present embodiment, the plating layer 20 is formed as a single layer, but is not necessarily limited to such a configuration, and the plating layer 20 may be formed as a plurality of layers.
For example, the inner layer can be made of nickel and the outer layer can be made of two layers made of nickel alloy containing tungsten. By setting it as such a structure, while having sufficient hardness, it can be set as the diamond wire saw with the high retention property of the diamond abrasive grain 30. FIG.

  Next, with reference to FIGS. 3-5, the manufacturing method of the diamond wire saw which concerns on embodiment of this invention is demonstrated.

  As shown in FIG. 3, the diamond wire saw 1 according to the embodiment of the present invention has a metal core wire 10 supplied from a roll 40 that is a supply source of the metal core wire 10, a degreasing tank 60, via a pulley 50, It is manufactured by passing through the pickling tank 70, the washing tank 80, the plating tank 90, and the washing tank 100, and being wound around the roll 41.

  The pulley 50 is for changing the traveling direction of the metal core wire 10, and as shown in FIG. 3, the degreasing tank 60, the pickling tank 70, the washing tank 80, the plating tank 90, the washing tank 100, and A plurality of tanks are provided in the tank.

The degreasing tank 60 is a tank in which, for example, an aqueous solution of sodium hydroxide (NaOH) is stored, and dirt such as oil adhering to the surface of the metal core wire 10 is removed by a degreasing process including the degreasing tank 60. Is done.
The aqueous solution stored in the degreasing tank 60 may be any one as long as it is normally used in the degreasing tank.

The pickling tank 70 is a tank in which, for example, a hydrochloric acid (HCl) aqueous solution is stored, and an oxide layer (rust) attached to the surface of the metal core wire 10 by a pickling process including the pickling tank 70. ) Is removed.
The aqueous solution stored in the pickling tank 70 may be any solution as long as it is normally used in the pickling tank.

  The water washing tank 80 is a tank in which tap water, well water, and pure water are stored, and the chemical solution adhering to the surface of the metal core wire 10 is diluted by the water washing process provided with the water washing tank 80, and the next process. It is possible to prevent the chemical solution from being mixed into the plating layer in the diamond abrasive electrodeposition process.

  The plating tank 90 is a tank responsible for a diamond abrasive electrodeposition process for performing electrolytic plating on the metal core wire 10 using a nickel-tungsten bath in which diamond abrasive grains 30 are dispersed in a solution in which nickel and tungsten are dissolved. It is.

  Hereinafter, the diamond abrasive electrodeposition process will be described in detail with reference to FIG.

  As shown in FIG. 4, the diamond abrasive grain electrodeposition process is performed using a plating tank 90 having a two-tank structure separated into an anode chamber 91 and a plating chamber 92 by a cation exchange membrane 91c described later.

  The anode chamber 91 is composed of an insoluble anode 91a connected to the anode of the power source 200, a solution 91b, and a cation exchange membrane 91c.

  The insoluble anode 91a may be any material as long as it is normally used as an insoluble anode, such as stainless steel or platinum.

  As the solution 91b, nickel salt, sulfuric acid or the like excluding hydrochloric acid, nitric acid and its salt can be used. Hydrochloric acid, nitric acid and salts thereof cannot be used because they generate harmful chlorine gas and nitric oxide gas on the insoluble anode.

The cation exchange membrane 91c is a selective membrane for preventing direct contact between the insoluble anode 91a and a plating solution 92c described later, and preventing oxidative decomposition of citric acid or the like present as anions in the plating solution 92c. .
Thus, by performing the diamond abrasive electrodeposition process using the plating tank 90 having a two-tank structure separated into the anode chamber 91 and the plating chamber 92 by the cation exchange membrane 91c, the stability of the plating solution 92c is improved. It is possible to perform long-term continuous plating.
Since hydrogen ions generated in the insoluble anode 91a are cations, they pass through the cation exchange membrane 91c according to the energization flow rate and are carried to the plating chamber 92.

  The plating chamber 92 includes a nickel anode 92a and a tungsten anode 92b connected to the anode of the power source 200, and a plating solution 92c.

As shown in FIG. 4, the nickel anode 92a has a plate shape and is used for supplying nickel ions to the plating solution 92c. As the nickel anode 92a, a plate that can be used for known nickel plating, such as electrolytic nickel and S-nickel, can be used.
In the present embodiment, the nickel anode 92a has a plate-like configuration, but is not necessarily limited to such a configuration, and a chip-like configuration may be used. When using chips, use them in a titanium basket.
Further, since the dissolved state of the nickel anode 92 a is a cation, the nickel anode 92 a may be arranged in the anode chamber 91 instead of the plating chamber 92.

As shown in FIG. 4, the tungsten anode 92b has a plate shape and is used for supplying a tungsten component to the plating solution 92c. Metal tungsten can be used as the tungsten anode 92b.
In the present embodiment, the tungsten anode 92b has a plate-like configuration, but is not necessarily limited to such a configuration, and a chip-like configuration may be used. When using chips, use them in a titanium basket.

The plating solution 92c is a nickel-tungsten bath in which nickel and tungsten are dissolved in an aqueous solution such as nickel sulfate and diamond abrasive grains 30 (not shown) are dispersed. More specifically, it is composed of diammonium hydrogen citrate, sodium formate, nickel sulfate, and sodium tungstate.
By setting it as such a structure, since the stability of a plating bath is high and a lifetime is long, it can be set as the manufacturing method of the diamond wire saw excellent in productivity.
Here, the ratio of nickel and tungsten in the nickel-tungsten bath is 1 to 9 to 9 to 1 in terms of molar ratio. By setting it as such a structure, the nickel- tungsten plating film from which sufficient hardness is obtained can be obtained stably.

  Using such a plating solution 92c, as shown in FIG. 4, the metal core wire 10 is immersed in the plating solution 92c, the negative electrode of the power source 200 is connected to the metal core wire 10, and the insoluble anode 91a, the nickel anode 92a, By connecting the anode of the power source 200 to the tungsten anode 92b and performing electroplating by appropriately selecting the current density and plating time, the plating layer 20 is formed on the outer surface 11 of the metal core wire 10, and diamond grinding is performed. The grains 30 are held dispersed.

  The washing tank 100 is a tank in which tap water, well water, and pure water are stored, and the metal core wire 10 in which the diamond abrasive grains 30 are dispersedly held on the outer surface 11 is obtained by a washing process including the washing tank 100. After being washed with water, heat treatment is performed by a heat treatment step (not shown), and the diamond wire saw 1 is manufactured.

The diamond abrasive electrodeposition process is not limited to that of the present embodiment.
For example, between the water washing tank 80 and the plating tank 90, it is possible to provide a tank in which electrolytic plating is performed using a nickel bath in which diamond abrasive grains 30 are dispersed in a solution in which nickel is dissolved. In this case, the diamond abrasive grains 30 are not dispersed in the plating solution 92c in the plating tank 90.

By setting it as such a structure, the diamond abrasive grain 30 is temporarily fixed to the outer surface of the metal core wire 10 by the electroplating using a nickel bath. Thereafter, diamond abrasive grains 30 are permanently fixed to the outer surface of metal core wire 10 by electrolytic plating using a nickel-tungsten bath.
Therefore, the plating using the nickel-tungsten bath has low current efficiency and the upper limit of the applied current density is low, so that it takes time to form the same thickness compared to plating using the nickel bath. By temporarily fixing the diamond abrasive grains 30 to the outer surface of the metal core wire 10, the plating time can be shortened. Therefore, a diamond wire saw with good production efficiency can be produced.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples.
A diamond wire saw 1 was manufactured by the steps shown in FIGS.
A long piano wire having a diameter of 0.14 mm is continuously immersed in the degreasing tank 60, the pickling tank 70, and the water washing tank 80 at a feed rate of 10 m / min for degreasing treatment, and then the anode chamber is formed by the cation exchange membrane 91c. A diamond abrasive electrodeposition process in which electrolytic plating is performed in a plating tank 90 having a two-tank structure separated into 91 and a plating chamber 92 was performed.
Here, the prescription of the plating bath in the plating tank 90 is 0.4 mol of diammonium hydrogen citrate, 0.2 mol of sodium formate, 0.2 mol of nickel sulfate, and 0.2 mol of sodium tungstate.
The plating conditions are a bath temperature of 65 ° C., a current density of 10 A / dm ² , a time of 7.5 minutes, a pH of 6.0, and a standard current efficiency of 55%.
The diamond abrasive grains 30 dispersed in the plating bath were nickel plated diamond abrasive grains whose outer surfaces were coated with nickel. The nickel plating amount is 30 wt% with respect to the diamond abrasive grains, and the average grain diameter of the diamond abrasive grains 30 is 13.4 μm. Such diamond abrasive grains 30 were charged into the plating chamber 92 at 0.25 g / L.
After performing the diamond abrasive electrodeposition step, the metal core wire 10 that had been electrodeposited was washed with water in a water washing tank 100 and further subjected to heat treatment at 600 degrees to obtain a diamond wire saw having a hardness of 1000 HV (Vickers hardness). The proportion of tungsten on the surface of this diamond wire saw was 40 wt%.
As a reference material, FIG. 5 shows a change in hardening in the heat treatment of nickel-tungsten alloy plating of 40 wt% tungsten.

A diamond wire saw was manufactured by the steps shown in FIGS.
A long piano wire having a diameter of 0.14 mm is continuously immersed in a degreasing bath 60, a pickling bath 70, and a water washing bath 80 at a feed rate of 10 m / min for degreasing treatment. Electrolytic plating was performed using a nickel bath in which diamond abrasive grains 30 are dispersed in a solution in which is dissolved.
Here, the formulation of the nickel bath is 240 g / L of nickel sulfate hexahydrate, 45 g / L of nickel chloride hexahydrate, and 30 g / L of boric acid.
The plating conditions are a bath temperature of 50 ° C., a current density of 20 A / dm ² , a time of 1 minute, and a pH of 4.0.
The diamond abrasive grains 30 dispersed in the nickel bath were nickel-plated diamond abrasive grains whose outer surfaces were coated with nickel. The nickel plating amount is 30 wt% with respect to the diamond abrasive grains, and the average grain diameter of the diamond abrasive grains 30 is 13.4 μm. 0.25 g / L of such diamond abrasive grains 30 was charged into a nickel-dissolved solution.
As a result, a nickel plating having the same thickness as the electrolytic plating using a nickel-tungsten bath for 3.5 minutes could be formed.
Thereafter, electrolytic plating was performed using a nickel-tungsten bath in a two-tank plating tank 90 separated into an anode chamber 91 and a plating chamber 92 by a cation exchange membrane 91c.
Here, the prescription of the plating bath in the plating tank 90 is 0.4 mol of diammonium hydrogen citrate, 0.2 mol of sodium formate, 0.2 mol of nickel sulfate, and 0.2 mol of sodium tungstate.
The plating conditions are a bath temperature of 65 ° C., a current density of 10 A / dm ² , a time of 3.75 minutes, a pH of 6.0, and a standard current efficiency of 55%.
Thereafter, the metal core wire 10 was washed with a water washing tank 100 and further subjected to heat treatment at 600 degrees.
As a result, a diamond wire saw having a hardness 950 HV comparable to that of the diamond wire saw shown in Example 1 was obtained.
The proportion of tungsten on the surface of this diamond wire saw was 38 wt%.

  The present invention can be used as a wire tool for cutting a highly brittle material such as a silicon ingot.

DESCRIPTION OF SYMBOLS 1 Diamond wire saw 10 Metal core wire 11 Outer surface 20 Plating layer 30 Diamond abrasive grain 31 Outer surface 32 Plating layer 40 Roll 41 Roll 50 Pulley 60 Degreasing tank 70 Pickling tank 80 Washing tank 90 Plating tank 91 Anode chamber 91a Insoluble anode 91b Solution 91c Cation exchange membrane 92 Plating chamber 92a Nickel anode 92b Tungsten anode 92c Plating solution 100 Washing bath 200 Power supply

Claims (6)

  A diamond wire saw in which the entire outer surface of a metal core wire in which diamond abrasive grains are dispersed and held is coated with a plating layer, wherein the plating layer is a nickel alloy containing tungsten.   The diamond wire saw according to claim 1, wherein the nickel alloy contains 1 wt% to 60 wt% of tungsten.   A diamond wire saw manufacturing method in which diamond abrasive grains are dispersed and held on the outer surface of a metal core wire, wherein the metal core wire is made by dispersing diamond abrasive grains in a solution in which nickel and tungsten are dissolved. A diamond wire saw manufacturing method comprising a diamond abrasive electrodeposition process in which electrolytic plating is performed using a tungsten bath.   The method for producing a diamond wire saw according to claim 3, wherein the ratio of nickel to tungsten in the nickel-tungsten bath is 1 to 9 to 9 to 1 in terms of molar ratio.   The method for producing a diamond wire saw according to claim 3 or 4, wherein the diamond abrasive grain electrodeposition step is performed at a bath temperature of 50C to 75C.   6. The solution in the nickel-tungsten bath is an aqueous solution in which diammonium hydrogen citrate, sodium formate, nickel sulfate, and sodium tungstate are dissolved. The manufacturing method of the diamond wire saw of description.

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