JP2011230258A - Fixed abrasive grain wire saw, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixed abrasive grain wire saw having high discharge performance of chips, and capable of long-hour cutting in high tension, while maintaining high abrasive grain holding power.SOLUTION: A spiral adhesive layer 5 is formed by using an organic adhesive on an outer peripheral surface of a wire 2 of a single track having electric conductivity, and an abrasive grain 4 is primarily fixed to the outer peripheral surface of the wire 2 by sticking the abrasive grain 4 to the adhesive layer 5 and is secondarily fixed by a metal plating layer 6 by electrodeposition further from above it, so that an abrasive grain layer 3 is spirally formed on the outer peripheral surface of the wire 2.

Description

  The present invention relates to a fixed abrasive wire saw used when cutting an ingot of hard and brittle material such as silicon, sapphire, single crystal silicon carbide, ceramic material, and magnetic material, and a method for manufacturing the same.

  Conventionally, when an ingot of a hard and brittle material such as silicon, sapphire, or a magnetic material is cut to obtain a thin plate-like substrate, generally, the above thin plate-like substrate is formed using an inner peripheral grindstone to which abrasive grains are fixed. The processing method which cut | disconnected sheet by sheet was taken. However, in recent years, from the viewpoint of productivity in cutting processing and reduction of kerf loss that occurs in cutting processing, there are an increasing number of cases in which a processing method that simultaneously obtains a plurality of thin plate substrates using a wire saw is applied. .

  The above-mentioned processing method using a wire saw mainly includes a free abrasive grain method that cuts with a wire saw while supplying a slurry obtained by mixing abrasive grains such as alumina and silicon carbide and a dispersion material to a workpiece, and an outer peripheral surface. And a fixed abrasive system in which the workpiece is cut with a wire saw having abrasive grains fixed thereto. However, since the former free abrasive processing method has a problem of disposal of slurry after cutting processing and a problem that time is required for cutting processing, the latter fixed abrasive processing method is strongly demanded.

  Wire saws (fixed abrasive wire saws) used in the above-mentioned fixed abrasive method are made by fixing a large number of abrasive grains to the outer peripheral surface of a metal wire such as a piano wire as a core wire. Depending on the type of the binding material to be used, it is classified into a resin bond wire saw using a resin bond as a binding material and an electrodeposition wire saw using a metal plating layer such as nickel as a binding material.

  Among these, since the resin bond wire saw uses a resin having a relatively low mechanical strength as a binder, there is a problem that the abrasive grains are easily dropped or the resin is peeled off, and the abrasive holding power is small. In addition, since the protruding amount of the abrasive grains cannot be increased, there is a problem that clogging occurs during the cutting of the workpiece, and the grindability is remarkably lowered.

  On the other hand, the electrodeposition wire saw uses a metal plating layer such as nickel as a binder, and therefore has a relatively high mechanical strength compared to a resin bond wire saw. For this reason, it is more advantageous to use this electrodeposition wire saw than the resin bond wire saw.

  As an example of such an electrodeposition wire saw, Patent Document 1 proposes a wire saw in which abrasive grains whose surfaces are coated with a metal such as Ni, Ti, and Cu are randomly fixed to the surface of the core wire by electrodeposition. ing. Since this wire saw can reduce the thickness of the plating layer, there is an advantage that the protruding amount of abrasive grains is increased and the productivity is good.

  However, since the electrodeposited wire saw has abrasive grains fixed randomly on the surface of the core wire, the interval between the abrasive grains may be reduced, or the abrasive grains may be fixed adjacent to the traveling direction of the wire saw. Many have problems with it. In other words, in general, fixed abrasive wire saws are in contact with the work piece during the cutting process because of the approximately half circumference of the circular cross section of the wire saw. If it is small or the abrasive grains are adhering to each other in the wire saw traveling direction, the cutting is not excluded together with the cooling water when cutting the workpiece, and the abrasive grains are easily clogged. As a result, the cutting performance is deteriorated. In addition, there is a problem that the cutting operation becomes unstable and the wire saw is likely to bend or sway, and it is difficult to maintain the processing accuracy.

  In order to solve the above problem, for example, as disclosed in Patent Document 2 and Patent Document 3, it is desirable to fix the abrasive grains to the outer periphery of the core wire in a spiral shape.

However, the wire saw disclosed in Patent Document 2 is a resin bond wire saw because it uses a thermosetting resin to fix the abrasive grains, and therefore, the abrasive grains peculiar to the resin bond wire saw fall off. And the resin is easily peeled off, and the abrasive grain holding power is low.
In the wire saw disclosed in Patent Document 3, abrasive grains are fixed to a base metal wire wound in a coil shape with a metal bond layer, and a rope-shaped core wire is inserted into a hollow portion of the coil base metal wire. Therefore, there is a problem in that a large tension cannot be applied at the time of cutting the workpiece, and the processing accuracy is low.

JP 2006-181701 A JP 2003-80466 A JP 2004-17276 A

  In view of the above-described conventional problems, the present invention provides a fixed-abrasive wire saw that maintains high abrasive holding power, has high chip dischargeability, and can be cut for a long time with high tension. It is intended to do.

  In order to achieve the above object, the fixed abrasive wire of the present invention is a fixed abrasive wire in which an abrasive layer is formed by directly adhering a large number of abrasive grains to the outer peripheral surface of a single wire having conductivity. A saw, wherein the abrasive grains are primarily fixed to the outer peripheral surface of the wire by an adhesive layer spirally formed on the outer peripheral surface with an organic adhesive, and two metal plating layers by electrodeposition are used. The abrasive layer is spirally formed on the outer peripheral surface of the wire by being next fixed.

The abrasive used in the present invention is preferably one or a mixture of two or more selected from diamond abrasive, cBN abrasive, Al2O3 abrasive, and SiC abrasive.
In the present invention, preferably, the wire is a metal wire, the helical pitch of the abrasive layer is uniform in the axial direction of the wire, and the organic adhesive is a low melting point nylon fiber.

  Further, according to the present invention, the metal plating layer is further adhered to the outer peripheral surface of the wire while fixing a large number of abrasive grains with an organic adhesive while continuously moving the wire having conductivity with a single wire in the axial direction. A method of manufacturing a fixed-abrasive wire saw that adheres to form a helical abrasive layer is provided. The manufacturing method includes a first step of heating the wire to a melting temperature of the organic adhesive, and a thin wire-like organic adhesive is spirally wound around the outer peripheral surface of the wire heated in the first step. A second step of forming a spiral adhesive layer by adhering by melting, and a large number of abrasive grains are attached to the adhesive layer formed on the outer peripheral surface of the wire in the second step to form a primary A third step of fixing, and the wire on which the abrasive grains are primarily fixed in the third step are dipped in an electrolytic plating solution, and a metal plating layer is formed by electrodeposition on the entire outer peripheral surface of the wire to form the abrasive grains And a fourth step of forming the above-mentioned spiral abrasive layer on the outer peripheral surface of the wire.

  In the production method of the present invention, in the second step, the organic adhesive is melted in a spiral shape by winding the organic adhesive while rotating the outer periphery of the wire along a plane perpendicular to the axis of the wire. It is desirable to adhere.

  The fixed abrasive wire of the present invention uses a single wire as the core wire, and after the abrasive particles are primarily fixed to the surface of the wire with an adhesive layer with an organic adhesive, the metal plating layer by electrodeposition is further applied thereon. Since the abrasive grains are secondarily fixed to form a spiral abrasive layer, not only is the abrasive holding power superior to the abrasive holding power but also excellent chip evacuation, Long cutting with tension is also possible.

1 is a partial side view schematically showing an embodiment of a fixed abrasive wire saw according to the present invention in a state where some abrasive grains are omitted. It is a partial expanded sectional view of FIG. It is a conceptual diagram which shows the manufacturing process of the fixed abrasive wire saw of FIG. It is the schematic which shows the process of forming an adhesive bond layer with an organic adhesive. It is a scanning micrograph of the fixed abrasive wire saw which concerns on this invention. It is a schematic block diagram of the processing apparatus used for the cutting performance measurement of a wire saw.

Hereinafter, the fixed abrasive wire saw and the manufacturing method thereof according to the present invention will be described.
1 and 2 schematically show an embodiment of a fixed abrasive wire saw 1 according to the present invention. This wire saw 1 has a large number of abrasives on the outer peripheral surface of a single wire 2 having conductivity. The particles 4 are directly and spirally fixed directly by the adhesive layer 5 formed of the organic adhesive 5a (see FIG. 4), and then secondarily fixed by the metal plating layer 6 by electrodeposition. The spiral abrasive grain layer 3 is formed on the outer peripheral surface 2.

In the illustrated example, a state in which the abrasive grains 4 are fixed in a line along the adhesive layer 5 is shown. However, this is merely drawn in a simplified form, and in practice, the bonding is performed. Of course, a plurality of abrasive grains 4 may be fixed in a random arrangement in the width direction of the agent layer 5.
In the illustrated example, the abrasive grain layer 3 is formed along a single spiral, but the abrasive grain layer 3 may be formed along a double or triple spiral.

  The wire saw 1 can be manufactured by the method shown in FIG. According to this method, the wire 2 wound around the first bobbin 11 is pulled out from the first bobbin 11, and the first step 13 for preheating, the second step 14 for forming the adhesive layer 5, While being wound around the second bobbin 12 through the third step 15 for attaching the abrasive grains 4 to the adhesive layer 5, the fourth step 16 for electrodeposition, and the fifth step 17 for cleaning, The wire saw 1 is formed.

More specifically, the wire 2 wound around the first bobbin 11 is drawn out at a constant speed by the second bobbin 12 and first sent to the first step 13. This first step 13 is a pretreatment step for forming the adhesive layer 5 with the organic adhesive 5a on the outer periphery of the wire 2, and the wire 2 is converted into the organic by an electric heater or other appropriate heating means. Heat to the melting temperature of the adhesive 5a.
The wire 2 is preferably a metal wire made of processed spring steel such as brass-plated piano wire, hard steel wire, or stainless steel wire.

  The heated wire 2 is sent to the second step 14, and as can be seen from FIG. 4, the organic adhesive 5 a formed in a thin line shape such as a fiber or a thread is wound spirally here. The adhesive layer 5 is formed. That is, the adhesive supply source 18 that supplies the thin-line organic adhesive 5a moves the wire 2 around the axis L of the wire 2 (moving in the axis L direction) with respect to the wire 2 moving at a constant speed. ), The organic adhesive 5a fed from the adhesive supply source 18 is spirally wound around the outer peripheral surface of the wire 2. Then, the organic adhesive 5a is melted by the heat of the wire 2 and adheres to the wire 2 in a state of being diffused in a band shape, so that the spiral adhesive layer 5 is formed. At this time, the spiral pitch P of the adhesive layer 5 can be made uniform in the direction of the axis L by making the rotational speed of the adhesive supply source 18, that is, the organic adhesive 5a constant. However, if necessary, the helical pitch P of the adhesive layer 5 may be changed partially or entirely by changing the rotation speed of the organic adhesive 5a.

Further, as shown by a chain line in FIG. 4, the second adhesive supply source 18A is arranged at a position 180 degrees different from the adhesive supply source 18 along the plane 19, and the two adhesive supply sources 18, 18A are arranged. The adhesive layer 5 can also be formed in a double helix by rotating in synchronization. In this case, the spiral pitch of the adhesive layer 5 is ½ that when the adhesive layer 5 is a single spiral.
Thus, by arranging a plurality of adhesive supply sources 18 and 18A around the wire 2 at equal angular intervals, the same number of adhesive layers 5 as the adhesive supply sources 18 and 18A are formed in multiple layers. be able to.
As the organic adhesive 5a, for example, a low-melting point nylon fiber (manufactured by Toray Industries, Inc., trade name: Elder) can be preferably used.

Subsequently, the wire 2 is sent to a third step 15 where a large number of abrasive grains 4 are adhered to the adhesive layer 5 to be primarily fixed spirally to the outer peripheral surface of the wire 2 and dried. Is done.
As the abrasive grain 4, one kind or a mixture of two or more kinds selected from diamond abrasive grains, cBN abrasive grains, Al2O3 abrasive grains, and SiC abrasive grains are used. Preferably, the surface of the abrasive grain 4 is partially or entirely conductive.

  Next, the wire 2 to which the abrasive grains 4 are primarily fixed is sent to the fourth step 16, immersed in the electrolytic plating solution 21 in the plating tank 20, and electrodeposited while passing through the electrolytic plating solution 21. Then, the abrasive grains 4 are secondarily fixed by the metal plating layer 6 (see FIG. 2). That is, when the wire 2 passes through the plating tank 20 with the wire 2 as a cathode and a metal plate 22 such as nickel immersed in the electrolytic plating solution 21 as an anode, the outer peripheral surface of the wire 2 and the abrasive Plating metal is deposited on the surface of the grains 4, and each abrasive grain 4 that is primarily fixed to the wire 2 by the adhesive layer 5 is secondarily fixed by a metal plating layer 6 made of nickel.

The preferred thickness of the metal plating layer 6 is in the range of 30-50% of the average grain size of the abrasive grains 4, more preferably in the range of 35-45%, and most preferably 40%.
The electrolytic plating solution 21 is made of, for example, nickel sulfamate, boric acid, nickel chloride, and additives.

And the said wire 2 which passed the said 4th process 16 is sent to the 5th process 17, and after it is washed by being immersed in the washing | cleaning liquid in a washing tank, it becomes the fixed abrasive wire saw 1 by drying. The second bobbin 12 is wound up.
In addition, the fixed abrasive wire saw of this invention and its manufacturing method are not limited to said embodiment, A various change can be added in the range which does not deviate from the main point of this invention.

  Hereinafter, the performance of an example of the present invention is compared with that of a comparative example, but the present invention is not meant to be limited to that of this example.

[Example]
FIG. 5 is a scanning electron micrograph of the fixed abrasive wire saw 1 according to the present invention manufactured by the method of FIG. The wire saw 1 uses a piano wire with a wire diameter of 0.12 mm, the surface of which is brass-plated, as the wire 2, and the abrasive grains 4 are made of abrasive grains having an average particle diameter of 15 μm whose surface is conductively coated with Ti. The twisted yarn-shaped organic adhesive 5a made of an organic compound having a diameter of 10 μm is wound around the outer circumference of the wire 2 in a double spiral shape to form an adhesive layer 5, and the adhesive layer 5 is used to form the abrasive grains 4. Is first fixed to the wire 2 and then secondarily fixed by nickel plating. The manufactured wire saw 1 had a wire diameter of 160 μm, and the metal plating layer 6 had a thickness of 7.2 μm.

[Comparative example]
As a comparative example, a fixed abrasive wire saw manufactured by the following method was used. This wire saw is an electrolysis in a suspension state in which a wire made of a piano wire with a wire diameter of 0.12 mm, the surface of which is brass-plated, and an abrasive having an average particle size of 15 μm, the surface of which is conductively coated with Ti, are dispersed. It is immersed in a plating solution, and the abrasive grains are randomly fixed to the outer peripheral surface of the wire by nickel plating. The wire saw had a wire diameter of 158 μm and a plating layer thickness of 7.1 μm.

  And while measuring the breaking strength and the number of twist cracks of the wire saw of the said Example and the wire saw of a comparative example, processing performance was measured and they were compared.

  Here, the number of twisting cracks means that the wire saw is chucked at two positions with a spacing of 100 mm, the load of 500 gf is forcibly applied and twisted 10 times, and then the metal plating layer is obtained with a 20 times optical microscope. The number of cracks that appeared on the surface of the film was measured.

  In the measurement of processing performance, a processing apparatus as shown in FIG. 6 is used, and the processing apparatus is equipped with the wire saw of the above example and the wire saw of the comparative example, and a single crystal silicon ingot (125 mm × 125 mm × 100 mm) 30 cuts were performed.

  The above-described processing apparatus has a known structure, and the wire saw Y drawn from the supply-side reel 31 is moved along the guide groove 32a to the two main rollers 32 provided with a spiral guide groove 32a on the outer periphery. As a result, a wire saw row YR in which the wire saws Y are parallel to each other at a constant pitch is formed between the upper portions of the main rollers 32 and 32, and the tip of the wire saw Y is wound around the collection-side reel 33. Is.

Then, by rotating the reels 31 and 33 and the two main rollers 32 in a reciprocating manner, the wire saws Y in the wire saw row YR are synchronized in the length direction (left and right direction in FIG. 6). The silicon ingot 30 is cut into a thin plate at a time with each wire saw Y in the wire saw row YR while reciprocating and feeding a new wire saw (new line) little by little from the supply-side reel 31 It is. At this time, the silicon ingot 30 is sent downward at a constant speed toward the wire saw row YR, and a water-soluble processing liquid is supplied to the processing portion.
In the portion of the wire saw row YR, each wire saw Y reciprocates at a fixed position and is not displaced in the central axis direction of the main roller 32.

Here, the arrangement interval of the wire saws Y in the wire saw row YR is 0.36 mm, the tension is 25 N, the reciprocating speed is 600 m \ min, the supply speed of the new line is 4 m \ min, and the feed speed of the silicon ingot 30 is The silicon ingot 30 was cut into 277 thin plate-like substrates at 60 mm \ h.
Then, for all thin plate-like substrates, a contact-type measuring instrument is used to measure thickness variation (difference between maximum and minimum thicknesses at five points in the substrate surface) and warpage (flatness from the cutting start end to the cutting end end). Measured in the above). The measurement results are shown in Table 1.

  As can be seen from Table 1, the wire saw of the present invention in which the abrasive grains are fixed to the wire in a spiral shape by the organic adhesive layer and the metal plating layer is more than the wire saw of the comparative example in which the abrasive grains are randomly fixed to the wire. The variation in the thickness of the cut workpiece can be reduced by 9 μm, and the warpage can be reduced by 8.5 μm.

DESCRIPTION OF SYMBOLS 1 Fixed abrasive wire saw 2 Wire 3 Abrasive layer 4 Abrasive grain 5 Adhesive layer 5a Organic adhesive 6 Metal plating layer 13 1st process 14 2nd process 15 3rd process 16 4th process 19 Plane 21 Electrolytic plating liquid

Claims (7)

A fixed abrasive wire saw in which an abrasive layer is formed by directly adhering a large number of abrasive grains to the outer peripheral surface of a wire having conductivity with a single wire,
The abrasive grains are primarily fixed to the outer peripheral surface of the wire by an adhesive layer spirally formed on the outer peripheral surface with an organic adhesive, and are secondarily fixed by a metal plating layer by electrodeposition. The fixed abrasive wire saw, wherein the abrasive grain layer is spirally formed on the outer peripheral surface of the wire.   The fixed abrasive according to claim 1, wherein the abrasive is one or a mixture of two or more selected from diamond abrasive, cBN abrasive, Al 2 O 3 abrasive, and SiC abrasive. Wire saw.   The fixed abrasive wire saw according to claim 1 or 2, wherein the wire is a metal wire.   The fixed abrasive wire saw according to any one of claims 1 to 3, wherein the helical pitch of the abrasive layer is substantially uniform in the axial direction of the wire.   5. The fixed abrasive wire saw according to claim 1, wherein the organic adhesive is a low melting point nylon fiber. While continuously moving a wire having conductivity with a single wire in the axial direction, a large number of abrasive grains are fixed to the outer peripheral surface of the wire with an organic adhesive and then fixed with a metal plating layer to form a helical abrasive. A method of manufacturing a fixed abrasive wire saw for forming a grain layer,
A first step of heating the wire to the melting temperature of the organic adhesive;
A second step of forming a spiral adhesive layer by winding the thin organic adhesive in a spiral and adhering it to the outer peripheral surface of the wire heated in the first step by spiral winding;
A third step of adhering a large number of abrasive grains to the adhesive layer formed on the outer peripheral surface of the wire in the second step and primarily fixing the adhesive layer;
By immersing the wire, on which the abrasive grains are primarily fixed in the third step, in an electrolytic plating solution, forming a metal plating layer by electrodeposition on the entire outer peripheral surface of the wire, and fixing the abrasive grains secondarily A fourth step of forming the spiral abrasive grain layer on the outer peripheral surface of the wire;
The manufacturing method of the fixed abrasive wire saw characterized by having.   In the second step, the organic adhesive is melted and bonded spirally by winding the organic adhesive around the outer peripheral surface of the wire while being rotated along a plane perpendicular to the axis of the wire. The manufacturing method of the fixed abrasive wire saw of Claim 6.