JPH11198017A - Wafer gap maintaining device and method for wire type cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wafers from stocking to each other when a work (a material to be cut) is cut. SOLUTION: With regard to a wire type cutting device (a wire saw), a gap retaining body 10 softer than the material of a work 3 is arranged movably in the work 3 feeding direction. The work 3 is cut as it is fed and, when a wafer 3a is formed, the end of the wafer 3a is intruded into the surface of the gap retaining body 10. A gap 4 between the wafers 3a is maintained because a part 10a of the surface of the gap retaining body 10 is intruded into the gap 4 between the wafers 3a. Adjoining wafers 3a are prevented from stocking to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for maintaining a gap between wafers in a wire-type cutting apparatus suitable for slicing so-called brittle materials such as semiconductor materials, magnetic materials, and ceramics into wafers.

[0002]

BACKGROUND OF THE INVENTION A wire cutting machine, also called a wire saw, has a plurality of groove rolls arranged in parallel. Cutting wires are stretched in parallel to the grooves of these groove rolls at regular intervals. The material to be cut is pressed against the traveling wire while the wire is moved in one direction and a processing liquid containing abrasive grains is sprayed by a nozzle, and the material to be cut is sliced into a wafer.

[0003] Wafers obtained by slicing are thin and have narrow gaps between them. For this reason, as shown in FIG. 5, the adjacent wafers 3a (the material to be cut is denoted by reference numeral 3 and the wafer is denoted by reference numeral 3a) may be brought into close contact with each other due to the surface tension of the processing liquid. If a plurality of wafers are attached, it becomes difficult to remove the wafer from the cutting wire when the slicing operation is completed. In addition, the accuracy of slicing is also reduced.

A processing method in which a comb gap is maintained by engaging a comb-shaped spacer having a large number of teeth with a wafer being sliced is disclosed in Japanese Patent Application No. 2-8519.
It is described in No. 5. However, in this method, it is difficult to correctly engage all of the large number of wafers with the comb-shaped spacer.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to enable a work of slicing a material to be cut while holding a gap between wafers.

According to the present invention, a cutting wire is hung on a plurality of groove rolls arranged in parallel, and at least one groove roll is driven to rotate so that the cutting wire travels. In a wire-type cutting device that supplies a processing liquid containing abrasive grains near the cutting point while feeding the wafer and slices the workpiece into a wafer, the tip of the wafer that is being sliced by the cutting wire is pressed. A gap holding member in which a surface portion is deformed and a part of the surface portion enters a gap between wafers, and the gap holding member is urged so as to face the feeding direction of the material to be cut, and It is characterized in that it has a support mechanism for supporting it to move in the feed direction according to the feed.

The present invention also provides a method suitable for a gap maintaining device for a material to be cut in the above-mentioned wire type cutting apparatus. That is, a cutting wire is hung on a plurality of groove rolls arranged in parallel, and at least one of the groove rolls is driven to rotate so that the cutting wire travels. In a wire cutting machine that supplies a working fluid containing abrasive grains to the vicinity and slices the material to be cut into a wafer, pressing the tip of the wafer that is being sliced by the cutting wire deforms the surface. The gap holding body, in which a part of the surface portion enters the gap between the wafers, is moved in the feeding direction in accordance with the feeding of the material to be cut while pressing the gap holding body against the tip of the wafer.

The wafer can be formed by slicing a material to be cut (generally a rod-shaped material) with a cutting wire running in parallel. Here, the wafer is being sliced (cut) (partly). In the state of being severed only when it is cut).

When a part of the material to be cut is cut by the traveling cutting wire, the cutting wire passes through and a cut groove is formed. The leading ends of the wafers are separated from each other by kerfs. In consideration of the rigidity of the wafer and the surface tension caused by the working fluid, the gap holding member is pressed against the tip of the wafer to be cut when the cutting of the tip of the wafer has not yet progressed so as to stick to each other ( Alternatively, the tip of the wafer is pressed against the surface of the gap holder.

When the tip of the wafer is pressed against the gap holder, the surface of the gap holder is deformed, and a part of the surface of the gap holder enters the gap between the wafers. This maintains the gap between the wafers. The gap holding member is urged in a direction facing the wafer. As the cutting proceeds, the material to be cut is further fed toward the cutting wire. Since the gap holding member is urged to face the wafer, a part of the surface of the gap holding body is kept in the gap between the wafers. The gap holding member also moves in the feeding direction with the transfer of the material to be cut while maintaining the above state. Therefore, the gap is maintained between the leading ends of the wafers until the slicing of the wafers is completed, so that adjacent wafers are prevented from sticking due to the surface tension of the processing liquid.

Preferably, an elastic body is used as the gap holding body. The elastic body deforms when the front end of the wafer is pressed, but returns to its original shape when the front end of the wafer separates. Therefore, the gap holding member can be used repeatedly, and there is no need to replace the gap holding member for each material to be cut.

[0012] Of course, the gap holding body is not limited to an elastic body, but may be made of a plastically deformable material such as clay or molding material.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of a groove roll, a support mechanism of a gap holding body, and a material to be cut in a wire cutting apparatus. FIG. 2 is a plan view of the gap holding body support mechanism and the material to be cut, and FIG. 3 is a side view of the gap holding body support mechanism.

Three groove rolls 21, 22 and 23 are rotatably supported at positions corresponding to the vertices of a right triangle and parallel to each other. Grooves are formed at regular intervals on the peripheral surfaces of the groove rolls 21 to 23, respectively. The spacing between the grooves defines the thickness of the wafer formed by cutting. A cutting wire 24 is sequentially wound around these groove rolls 21 to 23 along the grooves, and is wound by the number of grooves in each groove roll.

The cutting wire 24 is supplied from a wire feeding mechanism, and is wound by a wire winding mechanism (both not shown).

At least one of the three groove rolls 21 to 23 is driven to rotate, and the cutting wire 24 hung on the groove rolls 21 to 23 travels. The arrangement of the groove rolls 21 and 22 is in a vertical relationship. Therefore, the cutting wire 24 travels vertically downward (or upward) between the groove rolls 21 and 22.

A feeding device (not shown) for the work (material to be cut) 3 is arranged on the side (left side in FIGS. 1 to 3) of the cutting wire 24 running vertically between the groove rolls 21 and 22. I have. The work 3 is movably held by the feed device in a direction (horizontal direction) orthogonal to the cutting wire 24 running vertically.

On the opposite side of the workpiece feeder with the vertically running cutting wire 24 interposed (the right side of the vertically running cutting wire 24 in FIG. 1), the tip of the workpiece 3 fed by the feeder. The gap holding body 10 is supported by the support member 11 at a height position facing the horizontal direction (moving direction of the work 3) so as to be movable. The length of the gap holding body 10 is slightly longer than the width of the work 3. The gap holding member 10 is made of a material softer than the work 3 (for example, a neoprene open-cell sponge having a hardness of about 17 °). An elastic body is preferably used for the gap holding member 10, but a material that can be plastically deformed, such as clay or a molding material, can also be used. When an elastic body is used for the gap holding body 10, the gap holding body 10 returns to its original shape by elasticity when the wafer 3a is separated from the gap holding body 10. There is no need to replace 10.

Two guides 14 are horizontally arranged at positions on both sides of the path into which the work 3 is fed by the feeder, and are fixed to a frame (not shown). A roller 13 is rotatably provided at both ends of the support member 11 via a mounting member 12, and the roller 13 is movably held along a guide 14. Therefore, the support member 11 is supported movably in the horizontal direction in the direction in which the work 3 moves. The gap holder 10 attached to the support member 11 is horizontal and parallel to the longitudinal direction of the work 3.

A stopper 15 is provided at the tip of the guide 14 (on the side of the work feeder). A pulley 18 is rotatably attached to a frame or other fixing member on an extension of the guide 14 on the side of the work feeder. A wire 16 having one end fixed to the mounting member 12 is hung on a pulley 18.
A weight 17 is provided at the other end of the wire 16. As a result, a force in the direction toward the work 3 is constantly applied to the gap holding member 10. The mounting member 12 of the support member and the gap holding member 10 is in contact with the stopper 15. The wire 16, the weight 17, and the pulley 18 may be provided for both guides 14, or may be provided for only one guide 14.

While the cutting wire 24 is running and a working fluid including abrasive grains is supplied from a working fluid supply device (not shown) to the processing location, the work 3 is moved by the feed device to the vertically running cutting wire 24. Pressing, the work 3 is cut. As described above, the gap holding body 10 is held at a position where the mounting member 12 contacts the stopper 15. In the initial stage of the cutting operation, the tip of the work 3 has not reached the position of the gap holding member 10 (see FIG. 4A).

When the work 3 is cut and a part of the work 3 is cut, a gap 4 is formed between the cut wafers 3a. As the work 3 advances, the tip of the wafer 3a hits the gap holding member 10. The work 3 is further sliced while being sent. The gap holding body 10 is pushed by the tip of the wafer 3a. Since the gap holding member 10 is made of a material softer than the work 3, the surface of the gap holding member 10 is deformed when the tip of the wafer 3a pushes the gap holding member 10, and the tip of the wafer 3a is A little bit into the surface of the. A portion 10a of the gap holder 10 enters the gap 4 between the wafers 3a (see FIG. 4B).
A portion 10a of the gap holder 10 enters the gap 4 between the tip of the wafer 3a and the tip of the wafer 3a, and maintains the gap 4 between the tip of the wafer 3a. No sticking due to surface tension. The initial position of the gap holding member 10 where the attachment member 12 contacts the stopper 15 is set to a position where the leading end portion of the wafer 3a and the gap holding member 10 come into contact with each other before the wafers 3a stick to each other at the beginning of slicing.

The work 3 is further fed and cut. The gap holder 10 maintains the state in which a part 10a of the gap holder 10 has entered the gap 4 between the front ends of the wafers 3a.
The gap holding body 10 is pushed in the same direction as the workpiece 3 along the guide 14 by being pushed against the gravity of the weight 17 by the tip end of a.

When the slicing of the work 3 is completed, the work 3 (wafer 3a) is returned to the original position by the feeder. Since the gap 4 between the leading ends of the wafer 3a is maintained by a part 10a of the gap holding body 10, the gap 4 is not in close contact. When returning the work 3 to the original position, the wafer 3a can be easily taken out from the cutting wire 24.

In the above embodiment, the gap holder 10 is pressed against the wafer 3a of the work 3 by the gravity of the weight 17. The gap holding body 10 may be urged in the direction of the work 3 using a spring or the like. Further, the support member 11 of the gap holding member 10 may be moved in conjunction with the feeding operation of the work feeding device.

In the above embodiment, the cutting wire is vertically upward,
Or run down. The present invention is also applicable to a wire-type cutting apparatus in which a cutting wire travels in a horizontal direction and an apparatus in which a cutting wire travels in an oblique direction. The number of groove rolls is not limited to three, but may be two or four or more.

[Brief description of the drawings]

FIG. 1 is a side view of a support mechanism of a groove roll and a gap holding member, and a work is shown in a cross section.

FIG. 2 is a plan view of a support mechanism of a gap holding body and a work.

FIG. 3 is a side view of a support mechanism of the gap holding member.

4A and 4B show a gap holding body, wherein FIG. 4A shows a state in which the tip of the work is not in contact with the gap holding body, and FIG. 4B shows a state in which the tip of the work pushes the gap holding body.

FIG. 5 shows a state in which adjacent wafers are stuck.

[Explanation of symbols]

 3 Work 3a Wafer 4 Gap 10 Gap holder 11 Support member 13, 18 Reel 14 Guide 21, 22, 23 Groove roll 24 Cutting wire

Claims (2)

[Claims] 1. A cutting wire is wound on a plurality of groove rolls arranged in parallel, and the cutting wire is run by rotating at least one groove roll, and a workpiece is fed into the running cutting wire. In a wire-type cutting machine that supplies a working fluid containing abrasive grains near the cutting point while slicing the material to be cut into a wafer, the front end of the wafer that is being sliced by the cutting wire is pressed. Is deformed so that a part of the surface portion enters into the gap between the wafers, and the gap holding body is urged so as to face the feeding direction of the material to be cut while feeding the material to be cut. A gap maintaining device for a wafer in a wire-type cutting apparatus, comprising: a support mechanism for supporting the wafer to move in a feed direction in response to the movement. 2. A cutting wire is hung on a plurality of groove rolls arranged in parallel, and the cutting wire is run by rotating at least one of the groove rolls, and the material to be cut is fed into the running cutting wire. In a wire-type cutting machine that supplies a working fluid containing abrasive grains near the cutting point while slicing the material to be cut into a wafer, the front end of the wafer that is being sliced by the cutting wire is pressed. Wire-type cutting, in which a part of the surface portion is deformed and a part of the surface enters the gap between the wafers, and is moved in the feeding direction according to the feeding of the material to be cut while pressing the gap holding body against the tip of the wafer. A method for maintaining a gap between wafers in a processing apparatus.