JP2002273663A - Resin bond wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve wire saw sharpness better by forming a spiral for improving supply of grinding fluid and evacuation of chips on a peripheral surface of a resin bond wire saw. SOLUTION: The wire saw 10 comprises a core wire 1 whose peripheral surface with the application of an adhesive 1a is wound with the spiral of a filament 2 wherein an abrasive grain layer 2b comprising diamond abrasive grains bonded with a phenol resin is formed on an outer surface of a piano wire 2a. The filament 2 projects from the peripheral surface of the core wire 1 and spirals on the core wire 1 to cause the projection to form the spiral. Grinding fluid is supplied and chips are evacuated along the spiral, so that the supply of grinding fluid and the evacuation of chips are improved to improve the sharpness of the wire saw 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed abrasive type wire saw using a resin bond, and more particularly to a resin bond wire saw capable of maintaining good sharpness from the beginning to the end of processing.

[0002]

2. Description of the Related Art In the field of manufacturing various semiconductor devices,
Although the performance has been improved by miniaturization of the wiring pattern, the miniaturization of the wiring pattern alone cannot keep up with the multifunctionality. Recently, the size of the chip itself has been increased. With the increase in the size of such chips, silicon wafers with large diameters have come to be used from the viewpoint of improving the yield, and the cutting method from the silicon ingot, which is the preceding process, has also been changed from the conventional inner peripheral blade cutting method. It is being shifted to the wire saw cut method, which can easily cope with large diameters.

[0003] As one of the wire saw cutting methods which has been mainly performed conventionally, there is a loose abrasive method using a slurry. In this loose abrasive method, a piano wire or an ultra-high strength alloy wire is run in strong contact with a silicon ingot, and a free abrasive such as WA or GC is applied to a portion where the piano wire or the ultra-high strength alloy wire is in contact. Cutting is performed while lubricating oil containing particles is injected. However, it is said that there is a limit to the cutting efficiency because the work environment is degraded and the work is contaminated due to the scattering of the lubricating oil, and it is not possible to control the depth of penetration of the abrasive grains into the work material uniformly. I have.

On the other hand, in recent years, a fixed abrasive method using a wire saw in which abrasive grains such as WA, GC, diamond, and CBN are fixed to the peripheral surface of a core wire has been proposed. As a wire saw used in the fixed abrasive method, an electrodeposited wire saw for fixing the abrasive grains by electrodeposition and a resin bond wire saw for fixing the abrasive grains using a resin (resin) as a binder are known. Even with these electrodeposited wire saws and resin bond wire saws, it is possible to cut with abrasive grains by running while strongly contacting the workpiece similarly to the loose abrasive method.

[0005] By the way, an electrodeposited wire saw spends time in a plating process for electrodepositing abrasive grains.
Manufacturing problems that it is virtually impossible to electrodeposit abrasive grains on the core wire of m, and usage problems that breakage tends to occur during processing due to low torsional strength and bending strength have been pointed out before. Was. Therefore, there is a history that a resin bond wire saw has been developed as an improvement over such a drawback of the electrodeposited wire saw.

An example of such a resin bond wire saw is disclosed in Japanese Patent Application Laid-Open No. 10-138114. The resin bond wire saw described in this publication has a configuration in which a high tensile strength metal is used as a core wire, and a polyamideimide resin is used as a binder and abrasive grains are dispersed and contained in the core wire to coat the core wire.

[0007]

According to such a resin-bonded wire saw, the problem of the electrodeposited wire saw can be solved. On the other hand, since the entire abrasive grains are covered with the resin, the protrusion amount of the abrasive grains is reduced. Is insufficient and the sharpness is poor. In contrast, Patent No. 30780
No. 20 discloses that the particle size of abrasive grains is 2 / th of the resin bond layer thickness.
A wire saw is described in which the filler is not less than 3 and not more than の of the core wire diameter, the elastic modulus and the softening temperature of the resin are not less than a specified value, and the filler contains less than ／ of the resin bond layer thickness.
According to this wire saw, since the abrasive grains are fixed to the outer periphery of the core wire by protruding and protruding, good sharpness is obtained.

[0008] However, the wire saw described in this patent publication has a problem in that when the abrasive grains are worn and the amount of the abrasive grains protruding is reduced, the ability to discharge chips is lost, and the processing efficiency is reduced.

On the other hand, in the field of electrodeposited wire saws, there is a wire saw in which two core wires having a uniform thickness are twisted and the surface thereof is electrodeposited with abrasive grains. In this wire saw,
There is an advantage that the supply of the grinding fluid and the discharge of the chips are improved by the spiral formed by the stranded wire. However, as described above, the electrodeposited wire saw has a problem that it is difficult to manufacture a long-distance wire saw, and the manufacturing cost is higher than a resin bond wire saw. Further, even if the stranded wire method is simply applied to a resin bond wire saw, a spiral is not formed because the resin flows into the gap between the stranded wires.

[0010] The problem to be solved by the present invention is to improve the sharpness of the wire saw by forming a spiral on the outer peripheral surface of the resin bond wire saw to improve the supply of the grinding fluid and the discharge of the chips.

[0011]

The present invention provides a resin bond wire saw having an abrasive layer formed on the surface of a core wire.
The linear body on which the abrasive layer is formed is spirally wound around the outer peripheral surface of the core wire and adhered.

[0012] By spirally winding and bonding a linear body having an abrasive layer formed on the outer peripheral surface of the core wire, the abrasive grains project from the outer peripheral surface of the core wire to a certain height. Forms a spiral, so that the supply of the grinding fluid and the discharge of the swarf become good, and the wire saw exhibits good sharpness from the beginning of processing. In this case, a plurality of linear bodies can be wound to form a double or triple spiral. To bond the linear body to the core wire, apply an adhesive to the core wire before winding the linear body around the core wire, or wind the linear body while applying the adhesive along the winding line on the core wire. A method can be adopted.

Here, as the core wire, a high tensile strength metal wire used in a conventional resin bond wire saw can be used. Further, as the linear body on which the abrasive grain layer is formed, a linear body in which abrasive grains are fixed to a thin wire with a resin bond, or a thin linear body containing abrasive grains in a resin is used. it can. In this case, by setting the outer diameter of the linear body to 1/2 to 1/10 of the outer diameter of the core wire, the supply of the grinding fluid and the discharge of the cutting chips can be maintained in the best condition. If the outer diameter of the linear body is larger than の of the outer diameter of the core wire, when the wire is wound around the core wire, the protruding height from the outer peripheral surface of the core wire becomes too large, and the finished wire diameter also increases accordingly. Not suitable for precision cutting wire saws. On the other hand, when the outer diameter of the linear body is smaller than 1/10 of the outer diameter of the core wire, when the wire is wound around the core wire, the protruding height from the outer peripheral surface of the core wire is small, so that the supply of the grinding fluid and the discharge of the chips are reduced. become worse.

As the abrasive grains for forming the abrasive layer, general abrasive grains such as GC, WA, B and C used in conventional wire saws and superabrasive grains such as diamond and CBN can be used. As the resin as the binder, a resin such as a phenol resin, a polyamide resin, and an acrylate resin, which is used as a binder for abrasive grains in a conventional resin bond wire saw, can be used. As the wire when the abrasive layer is fixed to the wire, a copper-plated or copper-tin-plated high tensile strength metal wire used as a core wire in a conventional resin bond wire saw is used. In this case, the outer diameter of the wire is 50 to
About 100 μm is appropriate.

The resin bond wire saw of the present invention can be manufactured by the following manufacturing method. When using a linear body in which an abrasive layer is fixed to a wire as a linear body to be wound around a core wire, a linear body in which an abrasive layer is fixed to a wire by a method similar to a conventional method of manufacturing a resin bond wire saw. It is manufactured by spirally winding the linear body around a core wire to which a liquid adhesive has been applied and which has been applied in advance, and the adhesive is cured. As a method of winding the linear body around the core wire, the bobbin around which the linear body is wound is wound while revolving around the core wire to which the adhesive has been applied.

When a linear body containing abrasive grains in a resin is used as the linear body to be wound around the core wire, a resin liquid mixed with the abrasive grains is injection-molded from a hole having a predetermined diameter to form the linear body. It is manufactured by spirally winding the linear body around a core wire to which a liquid adhesive has been applied and which has been applied in advance, and the adhesive is cured. As a method of winding the linear body around the core wire, as described above, the bobbin around which the linear body is wound is wound around the core wire to which the adhesive is applied while revolving around the core wire.

[0017]

FIG. 1 is a partial front view of a resin bond wire saw according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view taken along line AA of FIG.

The wire saw 10 according to the present embodiment comprises an adhesive 1
This is a wire saw in which a linear body 2 in which an abrasive layer is fixed to a wire is spirally wound around an outer peripheral surface of a core wire 1 coated with a. The core wire 1 is a piano wire, and the linear body 2 has an outer diameter of 40 μm.
Is formed with an abrasive layer 2b having a thickness of 20 μm on the outer surface of the piano wire 2a. The abrasive layer 2b is formed by fixing diamond abrasive grains having a particle size of M20 / 30 with a phenol resin.

As shown in FIG. 2, the linear body 2 after manufacturing (before use) protrudes from the outer peripheral surface of the core wire 1, and as shown in FIG. Since the wire is wound in a shape, the protruding portion forms a spiral. When cutting a silicon ingot or the like using the wire saw 10, the grinding fluid is supplied along the spiral and the chips are discharged. Therefore, the supply of the grinding fluid and the discharge of the chips are improved, and the sharpness of the wire saw 10 is improved.

FIG. 3 is a partial front view of a resin bond wire saw according to a second embodiment of the present invention, and FIG.
It is a longitudinal cross-sectional view by the arrow B.

The wire saw 20 of the present embodiment is made of an adhesive 1
This is a wire saw in which a linear body 12 containing abrasive grains in a resin is spirally wound around the outer peripheral surface of a core wire 11 coated with 1a. The core wire 11 is a piano wire having an outer diameter of 160 μm, which is the same as the core wire 1 of the wire saw 10 of the first embodiment. The linear body 12 is formed by molding diamond abrasive grains having a particle size of M40 / 60 with a polyimide resin into a linear body having an outer diameter of 70 μm. In the case of the present embodiment, similarly to the case of the first embodiment, the grinding fluid is supplied along the spiral and the chips are discharged, so that the supply of the grinding fluid and the discharge of the chips become good. Thus, the sharpness of the wire saw 20 is improved.

In order to confirm the effect of the present invention, a cutting test was performed using the wire saws 10 and 20 (inventive products 1 and 2) of the above embodiment and a conventional product. [Test conditions] Cutting device: Single wire cutting device Core wire speed: Average 400 m / min Core wire tension: 19.6N Working fluid: Water-soluble grinding fluid Workpiece: Silicon ingot

FIG. 5 shows the test results. FIG. 5 is a diagram showing the relationship between the processing amount and the sharpness. The vertical axis indicates the cutting speed (index),
The horizontal axis is the number of cut out ingots. As can be seen from the figure, the invention product 1 and the invention product 2 exhibited sharpness twice or more even at the lowest value as compared with the conventional product, and also exhibited stable sharpness. In addition, invented product 1 and invented product 2 had a stable and good discharge of chips throughout the entire processing period, and the accumulated amount of removal was three times or more that of the conventional product. From this result, the invention product has better sharpness from the beginning of processing than the conventional product,
And it was confirmed that the sharpness could be maintained for a long time.

[0024]

(1) A linear body in which abrasive grains are fixed to a thin wire with a resin bond, or a thin linear body containing abrasive grains in a resin is spirally wound around a core wire and adhered. As a result, the abrasive grains protrude from the outer peripheral surface of the core wire to a certain height, and since the linear body forms a spiral, the supply of the grinding fluid and the discharge of the cutting chips become better, and the wire saw Demonstrate good sharpness from the beginning of processing.

(2) Maintaining the supply of the grinding fluid and the discharge of the cutting chips in the best condition by setting the outer diameter of the wire wound around the core wire to be 1/2 to 1/10 of the outer diameter of the core wire. Can be.

[Brief description of the drawings]

FIG. 1 is a partial front view of a wire saw according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view taken along line AA of FIG.

FIG. 3 is a partial front view of a wire saw according to a second embodiment of the present invention.

FIG. 4 is a vertical sectional view taken along line BB of FIG. 3;

FIG. 5 is a diagram showing a cutting test result.

[Explanation of symbols]

 1,11 core wire 1a, 11a adhesive 2,12 linear body 2a piano wire 2b abrasive layer 10,20 wire saw

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Daisuke Hatate 210, Takeno, Tanushimaru-cho, Ukiha-gun, Fukuoka Prefecture Noritake Diamond Co., Ltd. F-term (reference) 3C058 AA05 AA09 CA01 CB03 CB05 CB10 DA03 3C063 AA08 AB09 BA16 BA27 BB02 BC03 BF09 BG01 BG19 BH07 CC16 EE31 FF20 3C069 AA01 BA06 BB01 BB02 BC02 CA04 DA06 EA01 EA02 EA03

Claims (3)

[Claims] 1. A resin bond wire saw in which an abrasive layer is formed on the surface of a core wire, wherein the linear body having the abrasive layer formed thereon is spirally wound around and bonded to the outer peripheral surface of the core wire. 2. The resin bond wire saw according to claim 1, wherein an outer diameter of the linear body on which the abrasive layer is formed is in a range of １ ／ to 1/10 of an outer diameter of the core wire. 3. The linear body on which the abrasive layer is formed is a linear body in which abrasive grains are fixed to a thin wire by a resin bond, or a thin linear body in which abrasive grains are contained in a resin. The resin bond wire saw according to claim 1 or 2.