JP2006179677A - Saw wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a saw wire with a carrier resin film in which a carry capacity of free abrasive grains by the saw wire is enhanced and the free abrasive grains can be stably drawn in (introduced) between a workpiece and the saw wire. <P>SOLUTION: In the saw wire A, the running wire A is brought into contact with the workpiece W, and also, the free abrasive grains are sprayed on a portion where the wire comes into contact with the workpiece, while the workpiece is subjected to a slicing process. The saw wire A is formed such that the outer peripheral face of the wire 1 is coated with an abrasive grain carrier resin film 2, and the sprayed free abrasive grains 3 are bitten into the abrasive grain carrier resin film 2, while the free abrasive grains 3 are drawn into the portion where the wire A comes into contact with the workpiece W. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a saw wire used as a wire saw when slicing (cutting) a workpiece such as silicon, quartz, or a magnetic material by a wire saw cutting method, and in particular, bringing a wire running at high speed into contact with the workpiece, The present invention relates to a saw wire for slicing a workpiece while spraying loose abrasive grains on a portion where the wire and the workpiece are in contact with each other.

  For example, when a silicon wafer is cut out from a silicon ingot by a wire saw cutting method, a so-called free abrasive grain method is used in which a slurry mixed with abrasive grains is sprayed on a portion where the saw wire and the silicon ingot (workpiece) are in contact with each other. It has been implemented conventionally. According to this loose abrasive method, it is possible to easily cope with an increase in the diameter of a silicon wafer, and it is possible to easily cut out a large number of thin wafers by using a large number of wires at the same time.

On the other hand, products (silicon wafers) sliced with saw wire are required to have extremely strict quality with respect to the accuracy of the slicing surface and warpage. In order to achieve the high quality, loose abrasive grains are formed between the workpiece and saw wire. It is an important factor to introduce the system stably.
However, high-strength, high-carbon steel (piano wire), ultra-high-strength alloy wire, etc. are used as the saw wire used in the loose-abrasive wire saw cutting method. In order to improve it, it has a smooth surface with ultra-thin brass plating or copper plating. Therefore, it is difficult to stably draw loose abrasive grains between the workpiece and the saw wire, and it is difficult to obtain a high-quality product (silicon wafer) with a high yield.

  Note that the above prior art known to the applicant of the present application is not related to the literature known invention, and therefore, prior art document information is not disclosed in the present specification.

  The present invention has been made in view of such a current situation, and when performing a wire saw cutting method using a loose abrasive method, a saw wire capable of stably pulling loose abrasive grains between a workpiece and a saw wire is provided. It is to be provided.

The saw wire of the present invention that achieves such an object is a saw wire for slicing a workpiece while bringing the traveling wire into contact with the workpiece and spraying free abrasive grains on the portion where the wire and the workpiece are in contact. Then, the outer peripheral surface of the wire is coated with an abrasive carrier resin film, and the free abrasive grains are bitten into the abrasive carrier resin film while the free abrasive grains are in contact with the portion where the wire and the workpiece are in contact with each other. It is characterized by being formed so as to be pulled in (Claim 1).
Under the present circumstances, it is preferable to use a thermosetting resin or a photocurable resin as resin which forms the said abrasive grain carrier resin film (Claim 2 or 3).
Moreover, it is preferable to mix a fine inorganic substance in the abrasive carrier resin film.
Further, the film thickness of the abrasive carrier resin film is preferably set in the range of 0.1 to 15 μm. (Claim 5)

According to the saw wire according to the present invention, the wire and the workpiece are formed by covering the outer peripheral surface of the wire with the abrasive carrier resin film and biting the free abrasive grains sprayed into the abrasive carrier resin film. Since it is formed so as to be drawn into the contacted part, when the wire saw cutting method by the loose abrasive method is performed, the loose abrasive bites into the abrasive carrier resin film relatively softer than that, and in that state Therefore, it is drawn between the workpiece and saw wire.
Accordingly, the carrying ability of the loose abrasive grains by the saw wire is improved, and the loose abrasive grains can be stably drawn (introduced) between the workpiece and the saw wire. As a result, according to the saw wire according to the present invention, a high-quality product (sliced product) can be produced with a high yield.

  In addition, by using a photo-curing resin as the resin that forms the abrasive carrier resin film covering the outer peripheral surface of the wire, the thermal influence on the material of the saw wire itself can be reduced or eliminated compared to other resins. At the same time, since the curing speed at the time of forming the abrasive carrier resin film is high, the productivity of the saw wire is improved, which is very beneficial in terms of both quality and price.

  Further, by mixing fine particles made of a hard inorganic substance such as zirconia or alumina in the abrasive carrier resin film, it is possible to suppress wear of the abrasive carrier resin film itself, and at the same time, resin to the abrasive carrier resin film. Since portions having different hardness can be formed between the film-only portion and the inorganic fine particle portion, it is possible to expect further improvement in carrying ability with respect to free abrasive grains.

Hereinafter, specific preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the illustrated embodiments.
Reference numeral A in the figure indicates a saw wire, reference numeral 1 indicates a wire constituting the saw wire A, and reference numeral 2 indicates an abrasive carrier resin film covering the outer peripheral surface of the wire 1.

  As the wire 1 constituting the saw wire A, high strength high carbon steel (piano wire) or ultra high strength alloy wire having a thickness (wire diameter) of 40 to 400 μm is used as in the conventional case, and the outer peripheral surface thereof is used. An abrasive carrier resin film 2 is formed over the entire surface.

The abrasive carrier resin film 2 has the role of drawing the loose abrasive grains 3 between the workpiece W and the saw wire A by causing the loose abrasive grains 3 sprayed between the workpiece W and the saw wire A to bite into the surface thereof. Uniform on the outer peripheral surface of the wire 1 using a thermosetting resin such as phenol, polyamide, epoxy or urethane, more preferably a photocurable resin such as epoxy or urethane. The coating is integrally formed to the thickness of
In addition, when coating the abrasive grain carrier resin film 2 on the outer peripheral surface of the wire 1, there is no restriction | limiting about the manufacturing method, A well-known method is employable.

At this time, the thickness of the abrasive carrier resin film 2 is determined by the wire diameter of the wire 1 used and the particle diameter of the free abrasive grains 3. That is, as the free abrasive grains 3 used in the free abrasive grain method in the wire saw cutting method, those having an average particle diameter in the range of 3 to 30 μm are usually used, and the free abrasive grains 3 in this range are applied to the surface thereof. It is preferable to set the thickness of the abrasive carrier resin film 2 that can effectively bite into the range of 0.1 to 15 μm.
If the thickness of the abrasive carrier resin film 2 is less than 0.1 μm, the carrying ability of the free abrasive grains cannot be exhibited, and the free abrasive grains 3 are effective on the surface even if the free abrasive grains 3 have a particle size of around 3 μm. It becomes impossible to stably pull in between the workpiece and the saw wire. Moreover, even when the loose abrasive grains 3 having an average particle size of about 30 μm are used, if the abrasive carrier resin film 2 has a thickness of 15 μm, the free abrasive grains 3 are effectively bited into the surface, and the workpiece and saw wire It can be pulled in stably during.
If the thickness of the abrasive carrier resin film 2 is more than 15 μm, it is not preferable because the thickness of the sliced sliced product (for example, silicon wafer) varies.

The abrasive carrier resin film 2 is preferably mixed with fine inorganic substances (inorganic fine particles) such as zirconia, silica, alumina, silicon carbide whisker having substantially the same hardness as the free abrasive grains 3 to be used. Incidentally, examples of the free abrasive grains 3 preferably used in the present invention include silica and alumina.
In this case, the inorganic fine particles to be used preferably have an average particle size in the range of 1/2 to 1/20 of the free abrasive particle size. If the particle size of the inorganic fine particles to be added is smaller than 1/20 of the free abrasive grains, the effect of suppressing the abrasion of the abrasive carrier resin film 2 itself cannot be exhibited. Is too large, and the pull of free abrasive grains is extremely reduced.

  Furthermore, the addition amount of the inorganic fine particles with respect to the amount of resin forming the abrasive carrier resin film 2 is preferably in the range of 5 to 30% by volume. If the addition amount of the inorganic fine particles is less than 5% by volume, the effect of suppressing the abrasion of the abrasive carrier resin film 2 itself cannot be exhibited, and if it exceeds 30% by volume, the holding power of the free abrasive grains is lost, which is not preferable. .

Using a high carbon steel steel wire having a wire diameter of 140 μm, an abrasive carrier resin film made of epoxy resin was uniformly coated on the outer peripheral surface to a thickness of 5 μm to obtain a saw wire. In addition, 10 volume% of silica which is an inorganic substance was added to said epoxy resin.
Using the obtained saw wire, a single-crystal silicon workpiece was sliced. A water-soluble slurry in which free abrasive grains having an average particle size of 10 μm were suspended in a glycol-based water-soluble coolant was sprayed between the workpiece and the saw wire.
As a result, free abrasive grains are drawn between the workpiece and the saw wire as the saw wire travels, and free abrasive grains are interposed between the workpiece and the saw wire as compared to a conventional saw wire without an abrasive carrier resin coating. The amount was greatly increased, and the slice performance could be improved from the initial slice stage.

The perspective view which shows an example of implementation of the saw wire which concerns on this invention. The schematic diagram explaining the state in which the loose abrasive has digged into the surface of a saw wire. The schematic diagram explaining the state which is slicing the workpiece | work with saw wire.

Explanation of symbols

A: Saw wire W: Workpiece 1: Wire 2: Abrasive carrier resin film 3: Free abrasive grain

Claims (5)

  A saw wire for slicing a workpiece while bringing the traveling wire into contact with the workpiece and spraying free abrasive grains on the portion where the wire and the workpiece are in contact, and the outer peripheral surface of the wire is an abrasive carrier resin The coating is covered with a film, and the free abrasive grains are formed so as to be drawn into the portion where the wire and the workpiece are in contact with each other, while the sprayed free abrasive grains are biting into the abrasive carrier resin film. Saw wire.   The saw wire according to claim 1, wherein the abrasive carrier resin film is formed of a thermosetting resin.     The saw wire according to claim 1, wherein the abrasive carrier resin film is formed of a photocurable resin.     The saw wire according to claim 1, 2 or 3, wherein a fine inorganic substance is mixed in the abrasive carrier resin film.     The saw wire according to any one of claims 1 to 4, wherein the abrasive carrier resin film has a thickness of 0.1 to 15 µm.

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