JP2000326324A - Cutting method by wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lowering of efficiency and the generation of saw marks following the drawing-out of wires after the completion of cutting. SOLUTION: When a work 30 is cut by a plurality of wires 13a, 13a... set in parallel in the horizontal direction, the work 30 is set on a work holding member 22 through a dummy material 23 in a cutting method. A space 24 having the width wider than that of a work is formed on the back of the dummy material 23, and cutting is carried out until a plurality of wires 13a, 13a... as reach the space 24. Since the wires are separated from the work holding member 22 simultaneously with the completion of cutting, the wire drawing-out operation is not required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cutting method using a wire saw.

[0002]

2. Description of the Related Art Wire saws have been used for cutting thin silicon wafers from silicon single crystals or ceramics. In cutting with a wire saw,
As shown in FIG. 7, the work 2 is cut into a plurality of thin wafers by raising and lowering (normally lowering) the work 2 with respect to a plurality of wires 1, 1... You. The cutting is performed by running the wires 1, 1,... In one direction or by repeating reciprocation.

In such cutting with a wire saw, the wires 1, 1,... Are bent by the processing load. In order to absorb the bending, the work 2 is fixed to the work holding member 5 via the dummy material 4, and cutting is continued until the most bent portion of the wires 1, 1. Will be
Here, the dummy material 4 is adhered to the back surface (the surface on the cutting end side) of the work 2 and is fixed to the work holding member 5 by adhesion or bolting.

The use of the dummy material 4 allows the wires 1, 1.
The work 2 is prevented from being left uncut regardless of the bending of the workpiece, but the wires 1, 1.
And the workpiece 2 after cutting continues to be fixed to the holding member 5 via the dummy material 4. For this reason, an operation of extracting the wires 1, 1,... Remaining in the dummy material 4 is required for removing the workpiece after cutting.

Conventionally, as a method of removing a wire for removing a workpiece, a method of intentionally cutting a wire and a so-called wire removal method of returning the wires 1, 1,... To their original positions are known. Since the method of intentionally cutting requires rewinding of the wire, wire removal is often used at present.

[0006]

However, cutting with a conventional wire saw has the following problems associated with this wire cutting.

The wire removal is performed by raising and lowering (usually ascending) the cut work 2 in a direction opposite to the cutting direction while the wires 1, 1,... Are running. Since there are a plurality of thin plates, they may be in close contact with each other due to the surface tension of the abrasive fluid or abrasive grains. When the thin plates adhere to each other, the wires 1, 1,... When the work 2 is continuously moved up and down in such a state, the surface of the thin plate has streaks. This is called a saw mark, and when it is remarkable, it is cut off by several tens of microns.

For this reason, when the wires 1, 1,... Do not come off, the lifting and lowering of the work 2 is temporarily stopped, and the wires 1, 1,.
Waiting for the alignment of the workpieces, or reversing the vertical movement of the work 2 to make the levels of the wires 1, 1,... Uniform, so that the wire removal is restarted. As a matter of fact, there is a problem that the work efficiency is reduced and the saw mark is generated.

Even if such an operation is performed, the wires 1, 1,... May not be aligned, and if the operation is continued as it is, the wires 1, 1,.
When 1... Is cut off, a severe saw mark is generated, and some products become unusable. For this reason, the wires 1, 1,... May be intentionally cut and taken out.

In any case, in the conventional cutting with a wire saw, it is necessary to remove the wire in order to take out the work after the cutting, and the occurrence of saw marks and a decrease in work efficiency due to the removal of the wire are serious problems.

An object of the present invention is to provide a cutting method using a wire saw that can quickly take out a work after cutting and does not cause any mechanical damage to the work.

[0012]

In order to achieve the above object, a cutting method using a wire saw according to the present invention is characterized in that, when a work is cut into a plurality of thin plates by a plurality of parallel wires, a cutting end side of the work is cut. Surface, and the dummy material is fixed to the work holding member while leaving a space at least in a portion corresponding to the width of the cut portion of the work, and until a plurality of parallel wires reach the space. By performing cutting, a plurality of thin plates are separated from the work holding member at the end of cutting.

In the cutting method using a wire saw according to the present invention,
Since the dummy material is cut out at the end of the cutting, a plurality of thin plates as the cut work are separated from the work holding member. For this reason, it is not necessary to remove the wire for taking out the work. Therefore, the occurrence of saw marks and the decrease in work efficiency due to the wire removal are prevented. In addition, despite cutting out the dummy material, cutting into the work holding member is prevented. The height of the space is set to such a size that the dummy material can be cut out while preventing the work holding member from being cut.

Regarding the mounting posture of the workpiece, the surface on the cutting start side may be directed upward or downward, but the downward direction is such that the plurality of thin plates separated from the work holding member at the end of cutting will have their own weight. , Which makes it easier to receive and take it out. Further, discharge of the abrasive fluid from the cutting groove during cutting is promoted. Mechanical damage due to the fall can be avoided by reducing the fall distance or installing a cushioning material at the contact portion.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an apparatus configuration diagram of a wire saw suitably used in the cutting method of the present invention, FIG. 2 is a front view of a work holding portion showing a state before starting cutting, and FIG. It is a front view of a work holding part.

As shown in FIGS. 1 and 2, the wire saw includes a cutting mechanism 10 and a work feeding mechanism 20 provided above the cutting mechanism.

The cutting mechanism 10 includes a plurality of pulleys 12, 12,... Provided in a frame 11, and pulleys 12, 12,.
And the wire 13 wound around. The wire 13 forms a wire row in which a plurality of wires 13a, 13a,.
Is driven by a driving device (not shown) so as to travel in one direction or to travel while repeating reciprocation.

A work receiver 14 is provided below the wires 13a. The work receiver 14 has a pan 14a also serving as an abrasive liquid receiver, and a plurality of horizontal bar-shaped support members 14b provided in the pan 14a. The pan 14a is in the form of a trolley, and is drawn out to the side from the use position surrounded by the frame 11, and is carried into the use position surrounded by the frame 11 from the side position. The support members 14b support the cut workpiece in an upright state in the pan 14a.

The work feeding mechanism 20 has a structure in which the work 30 is held downward and moved up and down below the elevating base 21. Specifically, the lift base 21 is driven to move up and down by a ball screw or the like. On the lower surface of the lifting base 21,
A bonding metal 22 as a work holding member is attached, and a dummy material 23 bonded to the back surface (the surface on the cutting end side, here, the upper surface) of the work 30 is bonded or bolted to the bonding metal 22.

The dummy material 23 here comprises a pair of spacers 23a, 23a on both sides, and a plate-like main body 23b astride the spacers 23a, 23a and attached to the lower surface thereof. The work 30 bonded to the lower surface of the main body 23b is fixed downward to the lower surface of the bonding hardware 22 by bonding or bolting to the lower surface of the bonding metal 22, and a space 24 is formed between the work 30 and the bonding metal 22. The space 24 is located on the back side of the work 30, and its width is set to be larger than the width of the work 30 in order to cut the work 30 over the entire width. When cutting a part of the work 30 in the width direction, the space 24 may be on the back side of the cut portion and may be wider than the lateral width of the cut portion.

Next, using the wire saw, the work 3
A method of cutting 0 will be described in detail.

With the lifting base 21 raised, the dummy material 24 bonded to the back surface of the work 30 is
Attach to the underside of. As a result, the work 30 is held above the wires 13a, 13a,. Further, the dummy material 23 is fixed to the adhesive fitting 22 leaving a space 24 at least in a portion corresponding to the work width.

When the mounting of the work 30 is completed, the lifting base 21 is gradually lowered while driving the wires 13a. Thereby, the work 30 is connected to the wire 13
a, 13a start to be cut from the surface (lower surface). The part where the cutting of the work 30 is completed is the wire 13a,
13a... Are lowered, and gradually inserted into the work receiver 14 arranged therebelow. The polishing liquid used for cutting is also collected in the work receiver 14. Then, as shown in FIG. 3, by lowering the work 30 until the wires 13a, 13a,.
0 is cut into a plurality of thin plates 31, 31...
At the same time as the completion of the cutting, it is separated from the adhesive fitting 22.

The cut work 30, that is, the thin plates 31, 3
Are dropped into the work receiver 14 by their own weight, and are supported by the support members 14b, 14b,. Thin plate 3 in work receiver 14
When 1, 31,... Are accommodated, the work receiver 14 is pulled out to the side. In addition, in order to secure a work space, the lifting base 21 is raised when the work is taken out.

Thus, the workpiece 30 after the cutting is not cut intentionally and the wire 13 is not cut off.
Removed from 2. Therefore, the occurrence of saw marks and the decrease in work efficiency due to the wire removal are prevented.

In order to avoid mechanical damage caused by the fall of the work 30 after cutting, the fall distance is preferably limited to 50 mm or less. Also, the support members 14b, 14b,.
Is preferably made of a resin or the like for absorbing shock or coated with a resin or the like.

FIG. 4 is a front view of a main part of the apparatus showing another work mounting structure. In the above embodiment, the dummy material 2
3, the space 24 is formed by the spacers 23a, 23a. However, as shown in FIG. 4, the space 24 can be formed by forming a wide and shallow groove on the surface of the adhesive fitting 22 as a work holding member. It is possible, and the forming means is not particularly limited.

FIGS. 5 and 6 are a front view and a side view of a main part of the apparatus showing still another work mounting structure. In the above-described embodiment, the work 30 is a rectangular block, but may be a cylindrical body. In this case, the surface of the dummy material 23 has an arcuate surface 23c corresponding to the outer circumferential surface thereof so as to fit the outer circumferential surface of the cylindrical body. It is said. Further, the work receiver 14 is also used for the work 3
It has a structure and shape corresponding to the shape of 0.

In the embodiment shown in FIGS. 1 to 3, the pulley 1
The number of 2 is four, but may be a three or two structure. The work receiver 14 also serves as a polishing liquid receiver, but it is also possible to adopt a structure in which the work receivers 14 are made independent and only the work receiver is taken out from the fixed polishing liquid receiver.

In the above embodiment, the work 30 is moved up and down. However, the cutting mechanism 10 can be moved up and down depending on the size and shape of the work 30.

The work 30 may be raised and lowered not only by lowering the work 30 relative to the cutting mechanism 10 but also by raising the work 30 relative to the cutting mechanism 10.

In this case, the work 30 is fixed upward with its surface (the surface on the cutting start side) facing upward, so that when the dummy material 23 is cut out with the wires 13a, 13a,. It is preferable to provide a work supporting mechanism for preventing or lifting the work 30. When the dummy 30 is cut out without supporting the work 30 when the work 30 is facing upward, the work 30 falls down or the space 24 is cut off.
Depress in.

The downward fixing in which the surface of the work 30 (the surface on the cutting start side) is directed downward is advantageous because there is no such concern and the work supporting mechanism can be omitted.

[0034]

As described above, according to the cutting method using a wire saw of the present invention, the dummy material joined to the back surface of the work is fixed to the work holding member while leaving a space at least in a portion corresponding to the work width. By cutting until a plurality of parallel wires reach the space, the cut work is separated from the work holding member at the same time as the end of cutting, so that neither wire cutting nor wire removal for work removal is required. . Therefore, a high quality cut thin plate product can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a side view of an apparatus configuration diagram of a wire saw suitably used in a cutting method of the present invention.

FIG. 2 is a front view of a work holding unit showing a state before starting cutting.

FIG. 3 is a front view of a work holding unit showing a state at the time of completion of cutting.

FIG. 4 is a front view of a main part of the apparatus showing another work mounting structure.

FIG. 5 is a front view and a side view of a main part of the apparatus showing still another work mounting structure.

FIG. 6 is a front view and a side view of a main part of the apparatus showing still another work mounting structure.

FIG. 7 is an explanatory diagram of a cutting method using a wire saw.

[Explanation of symbols]

 Reference Signs List 10 cutting mechanism 13 wire 14 work receiver 20 work feed mechanism 21 elevating base 22 adhesive metal (work holding member) 23 dummy material 24 space 30 work 31 thin plate (wafer)

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3C058 AA05 AB04 CA01 CA05 CB02 CB03 DA03 3C069 AA01 BA06 BB03 BB04 BC01 CA04 CB01 DA01 EA01 EA03 EA05

Claims (2)

[Claims] When a work is cut into a plurality of thin plates by a plurality of wires arranged in parallel, a dummy material is joined to a surface on a cutting end side of the work, and the dummy material is attached to at least a cut portion of the work. A plurality of thin plates are separated from the work holding member at the end of cutting by fixing to the work holding member while leaving a space in a portion corresponding to the width, and performing cutting until a plurality of parallel wires reach the space. A cutting method using a wire saw. 2. A method of fixing a dummy material to a work holding member with the surface on the cutting start side of the work facing downward, and dropping and collecting a plurality of thin plates separated from the work holding member at the end of cutting. The cutting method using a wire saw according to claim 1.