JP2012066335A - Electrodeposition fixed abrasive wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodeposition fixed abrasive wire capable of securing high efficiency of scraping chips out of a cut groove of a cut material and of inhibiting the degradation of cutting efficiency accompanying the wear of fixed abrasive grains.SOLUTION: On the outer peripheral face of a wire base material, a first linear electrodeposition part on which first fixed abrasive grains having predetermined grain sizes are linearly electrodeposited, and a second linear electrodeposition part on which second fixed abrasive grains having smaller grain sizes than the first fixed abrasive grains are linearly electrodeposited, are formed in an isolated manner, therefore securing high efficiency of scraping chips out of the cut groove of the cut material and inhibiting the degradation of cutting efficiency accompanying the wear of the fixed abrasive grains.

Description

  The present invention relates to an electrodeposited fixed abrasive wire, and more particularly to an electrodeposited fixed abrasive wire suitable for slicing brittle materials such as sapphire using a wire saw.

Today, a slice of a silicon ingot (material to be cut) by a wire saw is a free abrasive grain type slice that presses an ingot while supplying slurry containing loose abrasive grains to a wire train running between a plurality of globe rollers. The method is mainstream. Specifically, the free abrasive grains in the slurry are rubbed against the bottom of the cutting groove of the ingot by the wire, and the bottom is gradually scraped off by the grinding action of the free abrasive grains, so that the slicing proceeds.
However, in this loose abrasive system, the bottom is not scraped unless movable loose abrasive is interposed between the wire and the bottom of the cutting groove. Therefore, when the material to be cut is a brittle material such as sapphire or SiC that is difficult to process due to its high hardness, for example, the processing rate is greatly reduced compared to the case of a silicon ingot, and the slicing time becomes longer. Productivity was declining.

Therefore, in recent years, a slicing method using a fixed abrasive wire has been developed that can obtain a high cutting rate although the kerf loss is large as compared with the slicing method of the free abrasive method. In particular, in the case of an electrodeposited diamond wire in which diamond abrasive grains are dispersed on the outer peripheral surface of a wire base material, it is suitable for slicing an ingot made of the brittle material.
However, in the conventional electrodeposition-fixed diamond wire, the wire base has a circular cross section, and the diamond abrasive grains are distributed substantially uniformly over the entire outer peripheral surface of the wire base. Therefore, during slicing, it is not possible to secure a space (chip pocket) for scraping chips (cutting chips) accumulated in the cutting grooves, and the chips gradually accumulate in the slurry in the cutting grooves, and the ingot cutting efficiency by the fixed abrasives accordingly. Had fallen.

Thus, as conventional techniques for solving this problem, for example, those described in Patent Documents 1 to 3 are known.
In the conventional technique described in Patent Document 1, two spiral portions including a conductive spiral portion and an insulating spiral portion are formed on the first plating layer of the strand, and the second plating is formed on the conductive spiral portion. A diamond electrodeposited wire tool in which layers and diamond abrasive grains are electrodeposited. With this configuration, a spiral chip pocket is formed on the outer periphery of the wire, and the scraping efficiency of the chip accumulated in the cutting groove of the ingot can be increased.
Moreover, the prior art described in patent document 2 is the wire of the shape twisted helically. With this configuration, a recess (chip pocket) capable of holding the slurry is formed on the outer periphery of the wire, the slurry holding power is increased, and the ingot cutting efficiency is increased. In addition, the scraping efficiency of the chip from the cutting groove can be increased.

  The prior art described in Patent Document 3 is a wire tool for cutting a brittle material in which abrasive grains are uniformly electrodeposited on the surface of a core wire obtained by winding a plurality of strands. With this configuration, it is possible to sufficiently supply the machining fluid to the machining portion, and it is possible to obtain a wire tool that is easy to manufacture and excellent in machining efficiency and durability during material cutting. In addition, since the twisted wire is employed as the core wire, a trough that is a chip pocket is formed on the surface of the wire tool. As a result, the inflow of the machining fluid into the machining part is promoted, chips are discharged quickly, and deterioration of the ingot cutting performance due to clogging of the abrasive grains can be prevented.

JP-A-7-96454 Japanese Patent Laid-Open No. 11-10514 Japanese Patent Laid-Open No. 11-277398

As described above, in the conventional wires described in Patent Documents 1 to 3, are diamond electrode grains spirally electrodeposited on the outer peripheral surface of the wire (Patent Document 1) or whether one wire is twisted? (Patent Document 2) By winding two strands together (Patent Document 3), a chip pocket is formed on the outer periphery of the wire, and the scraping efficiency of the chip from the cutting groove of the ingot is increased.
However, in these conventional wires, fixed abrasive grains having the same particle size are fixed to the outer peripheral surface of the wire. For this reason, at the time of slicing the ingot, all the fixed abrasive grains rubbed against the bottom of the cutting groove of the ingot are almost uniformly worn, and the sharpness of the fixed abrasive grains and the cutting efficiency of the ingot cannot be recovered.

  Therefore, as a result of earnest research, the inventor has a first linear electrodeposition portion in which first fixed abrasive grains having a predetermined particle size are linearly arranged on the outer peripheral surface of the wire base material, and a first fixed abrasive. It was found that if the second fixed abrasive grains having a grain size smaller than the grains were formed apart from the second linear electrodeposition portion, the above-mentioned problems could be solved. Completed.

  The present invention provides an electrodeposited fixed abrasive wire that can ensure high scraping efficiency of chips from the cutting groove of the material to be cut and can suppress a decrease in cutting efficiency due to abrasion of the fixed abrasive. The purpose is to do.

  In the electrodeposition fixed abrasive wire used when slicing a large number of wafers from the material to be cut, the invention according to claim 1 is provided on the outer peripheral surface of the wire base material that is the main body of the electrodeposition fixed abrasive wire. A first linear electrodeposition portion in which first fixed abrasive grains having a predetermined grain size are electrodeposited linearly, and a second fixed abrasive grain having a grain size smaller than the first fixed abrasive grains is linear. This is an electrodeposition-fixed abrasive wire that is formed apart from the second linear electrodeposition portion that is electrodeposited.

  According to a second aspect of the present invention, the first linear electrodeposition part and the second linear electrodeposition part are parallel to each other and formed in a spiral shape on the outer peripheral surface of the wire base material. The electrodeposited fixed abrasive wire according to Item 1.

  According to a third aspect of the present invention, the particle size of the first fixed abrasive is 30 to 40 μm, and the particle size of the second fixed abrasive is 5 to 10 μm. It is a fixed abrasive wire.

According to the first aspect of the present invention, the first linear electrodeposition portion in which the first fixed abrasive grains are linearly arranged on the outer peripheral surface of the wire base material, and the grain size is smaller than that of the first fixed abrasive grains. Since the second linear electrodeposition portions in which the small second fixed abrasive grains are linearly arranged are formed in a separated state, chip pockets are formed between the two linear electrodeposition portions, A high scraping efficiency of the chip from the cutting groove can be ensured.
In addition, at the initial stage of cutting (slicing) of the material to be cut, cutting of the material to be cut by the first fixed abrasive having a large particle size proceeds, and the first fixed abrasive gradually loses its sharp corners. Wear out. Thereafter, when the particle size of the first fixed abrasive reaches the particle size of the second fixed abrasive, the unused second fixed abrasive having sharp corners becomes the bottom of the cutting groove of the material to be cut. Abut. Therefore, after that, the second fixed abrasive will take over the main grinding of the bottom of the cutting groove. As a result, it is possible to recover the cutting efficiency of the material to be cut which has been lowered due to the abrasion of the first fixed abrasive.

  In particular, according to the second aspect of the present invention, the first linear electrodeposition portion and the second linear electrodeposition portion are respectively formed in a spiral shape on the outer peripheral surface of the wire base material. That is, when the electrodeposited fixed abrasive wire is viewed from its axial direction, the first fixed abrasive and the second fixed abrasive are present over the entire circumference of the wire substrate. Therefore, at the time of cutting the material to be cut, the fixed abrasive can be rubbed against the entire bottom surface of the cutting groove of the material to be cut. Thereby, in the outer peripheral surface of a wire base material, the cutting efficiency of a to-be-cut material can be improved compared with the case where both linear electrodeposition parts are formed along the length direction of a wire.

  Further, according to the invention of claim 3, since the particle size of the first fixed abrasive is 30 to 40 μm and the particle size of the second fixed abrasive is 5 to 10 μm, the processing damage to the material to be cut is reduced. Suppressing and minimizing kerf loss makes it possible to slice with high cutting efficiency.

It is a principal part enlarged front view which shows the electrodeposition fixed abrasive wire which concerns on Example 1 of this invention. It is a perspective view of the wire saw which shows the slice process of the to-be-cut material by the electrodeposition fixed abrasive wire which concerns on Example 1 of this invention. It is a principal part expanded sectional view which shows the use condition of the electrodeposition fixed abrasive wire which concerns on Example 1 of this invention for the first time. It is a principal part expanded sectional view which shows the reuse state of the electrodeposition fixed abrasive wire which concerns on Example 1 of this invention. It is a principal part expansion perspective view which shows the electrodeposition fixed abrasive wire which concerns on Example 2 of this invention. It is a principal part expansion perspective view which shows the electrodeposition fixed abrasive wire which concerns on Example 3 of this invention. It is a principal part enlarged front view which shows the electrodeposition fixed abrasive wire of the test example of this invention. It is a principal part enlarged front view which shows the electrodeposition fixed abrasive wire of a comparative example. It is a principal part enlarged front view which shows the electrodeposition fixed abrasive wire of another comparative example. It is a principal part enlarged front view which shows the electrodeposition fixed abrasive wire of another comparative example.

  In this electrodeposition fixed abrasive wire used when slicing a large number of wafers from a material to be cut, the first fixed abrasive having a predetermined particle size is linearly formed on the outer peripheral surface of the wire base material. In a state where the arranged first linear electrodeposition portions and the second linear electrodeposition portions in which the second fixed abrasive grains having a particle size smaller than the first fixed abrasive grains are arranged linearly are separated from each other. Each is formed.

According to the present invention, when the material to be cut is cut, the chip pocket is formed between the two linear electrodeposition portions, and the high scraping efficiency of the chip from the cutting groove of the material to be cut can be ensured.
Moreover, at the initial stage of cutting the material to be cut, the cutting of the material to be cut proceeds by the first fixed abrasive having a large particle size (average particle size). That is, the first fixed abrasive fixed to the wire base material is rubbed against the bottom of the cutting groove of the material to be cut, and the acute corner of the first fixed abrasive is gradually scraped off the bottom to cut the material to be cut. Cutting progresses. Along with this, the corners of the first fixed abrasive used for cutting gradually disappear. At the initial stage of cutting of the material to be cut, the rate of cutting (grinding) of the material to be cut is high since the corner missing rate of the first fixed abrasive grains is low. However, if the grinding proceeds, the missing rate of the corners of the first fixed abrasive increases, and the corners become rounded. Therefore, even if cutting of the material to be cut is continued, the sharpness of the first fixed abrasive is deteriorated, and the cutting efficiency of the material to be cut is lowered.

  However, when the first fixed abrasive is worn out and the particle size reaches the particle size of the second fixed abrasive, the second fixed abrasive having sharp corners is formed in the cutting groove of the material to be cut. Contact the bottom. Therefore, after that, the second fixed abrasive takes over the main grinding of the bottom of the cutting groove of the material to be cut, and the cutting efficiency of the material to be cut, which has been reduced due to the wear of the first fixed abrasive, is recovered. can do. In addition, after that, the first fixed abrasive with rounded corners and the second fixed abrasive with sharp corners cooperate to cut the material to be cut, so that the cutting efficiency is high for a long time. Maintained. Thereby, for example, even when reusing a plurality of materials to be cut, it becomes possible to stably cut the material to be cut.

An electrodeposition-fixed abrasive wire is one in which abrasive grains are electrodeposited on the outer peripheral surface of a wire base material. As a manufacturing method thereof, for example, the surface of a metal-plated wire base material is coated with a synthetic resin to form a coating film, and then a first electrodeposition groove and a second electrodeposition groove are formed on the coating film. Are formed in a separated state. Next, the first fixed abrasive grains are electrodeposited over the entire length of the first electrodeposition groove to form a first linear electrodeposition portion on the wire base material. In addition, the second electrodeposition groove is formed by electrodepositing the second fixed abrasive grains over the entire length of the groove to form a second linear electrodeposition portion separated from the first linear electrodeposition portion. An electrodeposited fixed abrasive wire is obtained.
As the material to be cut, for example, a brittle material such as sapphire or SiC, a monocrystalline or polycrystalline silicon ingot, or the like can be employed.

As a slicing device in which an electrodeposited fixed abrasive wire is used, for example, a wire array given a predetermined tension is reciprocated and pressed against the material to be cut. A wire saw that cuts (slices) a single wafer can be employed.
As the processing liquid supplied to the wire row when slicing the material to be cut, pure water (ultra pure water) that does not contain free abrasive grains such as silica grains can be used. Of course, a slurry containing loose abrasive grains may be used.

As the wire base material, for example, a steel wire such as a piano wire, a tungsten wire, a molybdenum wire, or the like can be employed.
The diameter of the wire substrate is 50 to 500 μm. If it is less than 50 μm, the electrodeposition-fixed abrasive wire is easily broken. Further, if it exceeds 500 μm, kerf loss increases and the number of wafers sliced from one material to be cut decreases. The diameter of a preferable wire base material is 70 to 400 μm. Within this range, it is possible to efficiently extract a wafer from a brittle material without disconnecting the electrodeposited fixed abrasive wire.
Each shape (appearance shape on the wire base material) of the first linear electrodeposition portion and the second linear electrodeposition portion is, for example, a spiral shape, a straight shape long in the length direction of the wire base material, a wire A ring shape orthogonal to the length direction of the substrate can be adopted. Further, the shape of the first linear electrodeposition portion and the shape of the second linear electrodeposition portion may be the same shape or different shapes.

In the present invention, it is desirable that the first linear electrodeposition portion and the second linear electrodeposition portion are spirally formed on the outer peripheral surface of the wire base material while maintaining a parallel state to each other. As a result, the abrasive grains can be electrodeposited on the entire outer periphery (360 °) of the wire, and the discharge efficiency of cutting waste accompanying the twisting of the wire being cut increases. In this case, the distance between the first linear electrodeposition part and the second linear electrodeposition part is 90 to 500 μm. If it is less than 90 μm, the distance between the abrasive grains is too small, and spiral processing for electrodepositing the abrasive grains on the wire base material becomes difficult, and the chip pocket size is reduced and the discharge efficiency of the cutting waste is lowered. Moreover, if it exceeds 500 micrometers, the absolute number of the abrasive grain per unit length will decrease, and cutting efficiency will fall. A preferable separation distance between both linear electrodeposition portions is 185 to 210 μm. If it is this range, the industrial merit that the discharge efficiency and cutting efficiency of cutting waste will be high, and spiral processing will also become easy is acquired.

The number of each of the first linear electrodeposition portions and the second linear electrodeposition portions may be one or two or more.
On the outer peripheral surface of the wire base material, in addition to the first linear electrodeposition part and the second linear electrodeposition part, the particle size of the fixed abrasive is different from that of the two linear electrodeposition parts (first 3, 4 ...) linear electrodeposits may be formed.
Diamond, silica, SiC, alumina, zirconia, or the like can be used as the material of the first fixed abrasive and the material of the second fixed abrasive. Diamond is particularly desirable. The first fixed abrasive and the second fixed abrasive may be the same material or different materials.

  In the electrodeposited fixed abrasive wire of this invention, it is desirable that the first fixed abrasive grain size is 30 to 40 μm and the second fixed abrasive grain size is 5 to 10 μm. When the particle size of the first abrasive grains is less than 30 μm, the initial cutting efficiency of the material to be cut decreases because the size of the abrasive grains is small. On the other hand, if the thickness exceeds 40 μm, the size of the abrasive grains increases, so that damage to the material to be cut increases, the work strain layer of the material to be cut increases, and kerf loss increases. When the particle size of the second abrasive grains is less than 5 μm, since the size of the abrasive grains is small, the cutting efficiency of the material to be cut after the first abrasive grains are worn down significantly decreases. Moreover, since the size of an abrasive grain will become large if it exceeds 10 micrometers, a 2nd abrasive grain will be exposed in the state with the high cutting ability of a 1st abrasive grain. As a result, although the cutting efficiency is high, the wear of the first fixed abrasive and the wear of the second fixed abrasive proceed together, so the life of the wire is shortened.

  Examples of the present invention will be specifically described below. Here, the electrodeposition fixed abrasive wire used in the wire saw which slices a sapphire ingot is taken as an example.

1 and 2, reference numeral 10 denotes a wire saw using the electrodeposition-fixed abrasive wire 11 according to Embodiment 1 of the present invention. A crystal block I which is block-cut from a sapphire ingot and cylindrically ground is used as a material to be cut. This is an apparatus for slicing a large number of sapphire wafers from the crystal block I.
Specifically, the wire saw 10 includes three wire saw groove rollers (hereinafter referred to as groove rollers) 12A to 12C arranged in a triangular shape when viewed from the front. Between these groove rollers 12A to 12C, one electrodeposited fixed abrasive wire 11 is wound at a constant pitch so as to be parallel to each other. Thereby, the wire row 13 appears between the groove rollers 12A to 12C. In FIG. 2, 14 is a pure water supply nozzle, and 15 is a lift for the crystal block I.

  As shown in FIG. 1, the electrodeposited fixed abrasive wire 11 includes a first fixed abrasive 17 made of diamond having a particle size of 30 to 40 μm and a particle size of 5 to 5 on the surface of a steel wire substrate 16 having a diameter of 180 μm. The second fixed abrasive grains 18 made of 10 μm diamond are electrodeposited in a double spiral shape while maintaining the distance d (185 to 210 μm), and the first linear electrodeposition portion 20 and the second linear shape are deposited. The electrodeposition portion 22 is formed. Next, the manufacturing method of the electrodeposition fixed abrasive wire 11 is demonstrated concretely.

  A wire base 16 made of nickel-plated piano wire is prepared, and the outer peripheral surface of the wire base 16 is covered with a synthetic resin (fluororesin) to form a coating film having a thickness of 10 μm. Thereafter, one spiral first electrodeposition groove 19 having a width of 60 μm is formed in the coating film using a spiral processing machine. Next, the first fixed abrasive grains 17 are electrodeposited over the entire length of the first electrodeposition groove 19. Specifically, the surface of the piano wire is nickel-plated by a known nickel plating apparatus, and the plated surface is covered with a synthetic resin (here, a fluororesin) which is a non-conductive substance. Next, in order to form a conductive portion in a spiral shape on the outer peripheral surface of the electrodeposited fixed abrasive wire 11, the synthetic resin film is removed in a spiral shape using a known spiral processing machine, and an exposed spiral shape is formed. A diamond abrasive grain having a predetermined particle size is nickel-plated (electrodeposited) on the conductive portion (nickel). Thereby, the 1st linear electrodeposition part 20 is formed in the outer peripheral surface of the wire base material 16. As shown in FIG.

  Thereafter, the spiral processing machine is used again, and the second electrode parallel to the first electrodeposition groove 19 is positioned at the position of the coating film shifted by 180 ° in the circumferential direction of the wire base material 16 with respect to the first electrodeposition groove 19. The electrodeposition groove 21 is formed in a spiral shape. That is, here, the second electrodeposition grooves 21 are arranged between the pitches of the spiral first electrodeposition grooves 19, and the torsion angles between the first electrodeposition grooves 19 and the second electrodeposition grooves 21 are set. Identical. Thereafter, the second fixed abrasive grains 18 are electrodeposited over the entire length of the second electrodeposition groove 21. Specifically, a conductive portion is formed in a spiral shape on the outer peripheral surface of the electrodeposited fixed abrasive wire 11 at a position shifted by 90 degrees in the circumferential direction of the wire base material 16 with respect to the first fixed abrasive 17. For this purpose, the synthetic resin film is removed in a spiral shape using a known spiral processing machine, and the exposed spiral conductive portion is nickel-plated with diamond abrasive grains having a predetermined particle size. Thereby, the 1st linear electrodeposition part 20 is formed in the outer peripheral surface of the wire base material 16. As shown in FIG. Thus, the electrodeposition-fixed abrasive wire 11 having the double spiral linear electrodeposition portions 20 and 22 having different abrasive grain sizes is manufactured.

Next, with reference to FIG. 2, the slicing method of the crystal block I of Example 1 using the electrodeposition fixed abrasive wire 11 is demonstrated.
When slicing the crystal block I, the electrodeposited fixed abrasive wire 11 is led out from the bobbin of the feeding device, travels through each of the groove rollers 12A to 12C via the supply side guide roller, and then passes through the guide roller on the lead side. And wound on the bobbin of the winding device. The wire row 13 is reciprocated by the main motor between the three groove rollers 12A to 12C. For this reason, the roles of the feeding device and the winding device are alternately changed. The middle of the two groove rollers 12A and 12B arranged on the lower side is the cutting position of the crystal block I. Above one side of the cutting position, a pure water supply nozzle 14 that continuously supplies pure water onto the wire row 13 is provided. While supplying pure water of 10 liter / min from the pure water supply nozzle 14 to the wire row 13, the crystal block I is pressed at 1.0 mm / min from below onto the wire row 13 that is reciprocating at 1 m / min. Block I is sliced into multiple sapphire wafers.

When the crystal block I is cut, a chip pocket is formed between the first linear electrodeposition portion 20 and the second linear electrodeposition portion 22. Thereby, high scraping efficiency of the chip from the cutting groove Ia of the crystal block I can be ensured.
In addition, at the initial stage of cutting the crystal block I, the cutting of the crystal block I by the first fixed abrasive grains 17 having a large particle size proceeds (FIG. 3a). That is, the first fixed abrasive grains 17 fixed to the wire base 16 are rubbed against the bottom of the cutting groove Ia of the crystal block I, and the sharp corners of the first fixed abrasive grains 17 are gradually scraped off from the bottom. The cutting of the crystal block I proceeds. Along with this, the corners of the first fixed abrasive grains 17 used for cutting gradually disappear. At the initial cutting stage of the crystal block I, the missing rate at the corners of the first fixed abrasive grains 17 is low, so that the processing (grinding) rate of the crystal block I is high. However, if the grinding proceeds, the missing rate of the corners of the first fixed abrasive 17 increases, and the corners become rounded. Therefore, even if the cutting of the crystal block I is continued, the sharpness of the first fixed abrasive grains 17 is deteriorated, and the cutting efficiency of the crystal block I is lowered.

  However, when the first fixed abrasive grains 17 are worn out and the particle size thereof reaches that of the second fixed abrasive grains 18, the second fixed abrasive grains 18 having sharp corners are formed on the crystal block I. It contacts the bottom of the cutting groove Ia (FIG. 3b). Therefore, after that, the second fixed abrasive 18 takes over the main grinding of the bottom of the cutting groove Ia of the crystal block I, and the cutting of the crystal block I has been reduced due to the wear of the first fixed abrasive 17. Efficiency can be restored. In addition, after that, the first fixed abrasive grains 17 with rounded corners and the second fixed abrasive grains 18 with sharp corners cooperate to cut the crystal block I, so that the cutting efficiency is high. Maintained for a long time. Thus, for example, even when two or three crystal blocks I are reused, the crystal blocks I can be stably cut.

Next, with reference to FIG. 4, the electrodeposition fixed abrasive wire which concerns on Example 2 of this invention is demonstrated. As shown in FIG. 4, the electrodeposition-fixed abrasive wire 11 </ b> A of Example 2 is characterized by a first linear electrodeposition portion 20 </ b> A and a second linear electrodeposition portion 20 </ b> A that extend linearly toward the length direction of the wire base 16. The linear electrodeposition portions 22A are alternately formed on the outer peripheral surface of the wire base material 16 every 90 ° in the circumferential direction. By comprising in this way, a big chip pocket can be ensured and the discharge efficiency of cutting waste can be kept high. In addition, the first fixed abrasive grains 17 and the second fixed abrasive grains 18 can be efficiently brought into contact with the cut surface by the twisting effect of the wire being cut.
When the linear first electrodeposition groove 19A and the second electrodeposition groove 21A are formed on the outer peripheral surface of the wire base material 16, a known processing machine is used. Other configurations, operations, and effects are within a range that can be estimated from the first embodiment, and thus description thereof is omitted.

  Next, with reference to FIG. 5, the electrodeposition fixed abrasive wire which concerns on Example 3 of this invention is demonstrated. As shown in FIG. 5, the electrodeposition-fixed abrasive wire 11 </ b> B of Example 3 is characterized by an annular first linear electrodeposition portion 20 </ b> B that is orthogonal to the length direction on the outer peripheral surface of the wire base 16. And the second linear electrodeposition portions 22B are alternately formed in the length direction of the wire base material 16 at intervals d1 (185 to 210 μm). When forming the annular first electrodeposition grooves 19B and second electrodeposition grooves 21B on the outer peripheral surface of the wire base material 16, a known processing machine is used. Other configurations, operations, and effects are within a range that can be estimated from the first embodiment, and thus description thereof is omitted.

(Test Examples 1 to 4, Comparative Examples 1 to 10)
Next, referring to FIGS. 6a to 6d and Table 1, the electrodeposition fixing of Example 1 in which the first fixed abrasive grains 17 and the second fixed abrasive grains 18 having different particle sizes are electrodeposited in a double spiral shape. An abrasive wire (hereinafter referred to as wire Y1; Test Examples 1 to 4, FIG. 6a) is an electrodeposited fixed abrasive wire (hereinafter referred to as wire Y2) in which only the second fixed abrasive 18 having a small particle size is spirally electrodeposited. Comparative Examples 1 to 3, FIG. 6b) and an electrodeposited fixed abrasive wire in which only the first fixed abrasive 17 having a large particle size is electrodeposited spirally (hereinafter, wire Y3; Comparative Examples 4 to 7, FIG. 6c) And a commercially available electrodeposition fixed abrasive wire (hereinafter referred to as wire Y4; Comparative Examples 8 to 10, FIG. 6d) in which fixed abrasive grains 17A having a particle size of 30 to 40 μm are dispersed throughout the outer peripheral surface. The chip scraping efficiency from the cutting groove Ia of the crystal block I made of sapphire in Example 1 is equal to or higher than that in the comparative example. And cutting efficiency due to the fixed abrasive wear to prove higher than Comparative Example.

  The wires Y1 and Y3 were reused three times after the first slice. On the other hand, the wires Y2 and Y4 were reused twice. Test Example 1 and Comparative Examples 1, 4, and 8 show slices at the first time, and Test Example 2 and Comparative Examples 2, 5, and 9 show slices at the first reuse. Test Example 3 and Comparative Examples 3, 6, and 10 show slices at the second reuse, and Test Example 4 and Comparative Example 7 show slices at the third reuse. In Table 1, the result of measuring the particle size of the fixed particles electrodeposited on the outer peripheral surface of the wire base material 16 with a laser microscope before performing the tests of Test Examples 1 to 4 and Comparative Examples 1 to 10 Is also described. The manufacturing conditions of the wires Y1 to Y4 and the cutting conditions of the crystal block I are both in accordance with the first embodiment.

As is apparent from Table 1, in the wire Y1 of Example 1, the wear of the fixed abrasive proceeds each time the reuse is repeated, and after the second reuse, the first fixed abrasive is used. The crystal block I was sliced with the grain size of 17 and the grain size of the second fixed abrasive grain 18 being the same. As a result, while maintaining the flatness (warp) and surface roughness Ra (roughness) of the wafer equivalent to or higher than those of the wires Y2 to Y4 of the comparative example, a higher cutting speed than the wires Y2 to Y4 of the comparative example ( The crystal block I could be cut with the cutting efficiency. The reason why the flatness and surface roughness of the wafer were good seems to be because the high scraping efficiency of the chip from the cutting groove Ia of the crystal block I could be secured during slicing.
On the other hand, in Comparative Example 6 showing the second reuse of the wire Y3, the first fixed abrasive grains 17 were severely worn, and the flatness and surface roughness of the wafer were also deteriorated. In particular, when the wires Y2 and Y4, which are comparative examples, are reused for the second time, and when the wire Y3, which is a comparative example, is reused for the third time, extreme bending occurs in the wire in the slice, which hinders the slice. Therefore, the slice was abandoned.

  The present invention is useful as a tool used for cutting highly brittle materials such as sapphire and SiC.

11, 11A, 11B Electrodeposition fixed abrasive wire,
16 wire substrate,
17 first fixed abrasive,
18 second fixed abrasive,
20, 20A, 20B 1st linear electrodeposition part,
22, 22A, 22B second linear electrodeposition portion,
I Crystal ingot (material to be cut).

Claims (3)

In the electrodeposition fixed abrasive wire used when slicing a large number of wafers from the material to be cut,
On the outer peripheral surface of the wire base material that becomes the main body of the electrodeposited fixed abrasive wire,
A first linear electrodeposition portion in which a first fixed abrasive having a predetermined particle size is electrodeposited linearly;
An electrodeposited fixed abrasive wire formed by separating a second linear electrodeposition portion in which a second fixed abrasive having a particle size smaller than that of the first fixed abrasive is electrodeposited linearly.   2. The electrodeposited fixed abrasive according to claim 1, wherein the first linear electrodeposition portion and the second linear electrodeposition portion are formed in parallel to each other and spirally on the outer peripheral surface of the wire base material. Grain wire. The particle size of the first fixed abrasive is 30 to 40 μm,
The electrodeposited fixed abrasive wire according to claim 1 or 2, wherein a particle size of the second fixed abrasive is 5 to 10 µm.

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