JPH09123161A - Device for holding work of wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a special separation device to proceed with separation of a slice base, and avoid an adhesive from remaining in the wafer in a work-holding device of a wire saw of the type of securing an attachment plate to the work with a slice base held therebetween and mounting the attachment plate on the movable block (being movable in the Z direction while holding the work). SOLUTION: An interior refrigeration 26 is installed inside of the movable block 23, and an exterior refrigerator 35 is also installed outside of the wire saw, and by the use of an exterior saw, the work W and slice base 31 are joined with each other via ice, and the work W is fixed to the movable block 23, and thereafter by means of the interior refrigerator 26, ice between the work W and the slice base 31 is maintained through refrigeration. After cutting, ice is allowed to melt, so that the slice base is separated from the work W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holding device for a wire saw that cuts a work into a thin plate by causing a wire having abrasive grains to travel at a high speed and pressing the work against the wire. In this specification, the three axial directions orthogonal to each other are referred to as the X direction, the Y direction, and the Z direction, respectively.

[0002]

2. Description of the Related Art A wire saw is one of the cutting devices for cutting a workpiece (hereinafter referred to as "workpiece") such as a semiconductor material (silicon or the like) or ceramics into a thin plate. This wire saw cuts a work by arranging a large number of wires to which abrasive grains are attached in parallel and running at high speed and pressing the work against the wires.

5 and 6 show the structure of the processing portion of an example of such a wire saw. In this example, the work is a cylindrical silicon ingot. FIG. 5 is a front view and corresponds to the C-C cross section of FIG. 6. FIG. 6 is a sectional view taken along the line BB of FIG. 5 (however, the support plate 11 is not shown). Each of them represents a state in which the work is being cut. As shown in FIGS. 5 and 6, the processing section is roughly divided into a wire drive section 10 and a work drive section 20.

In the wire driving unit 10, two supporting plates 11 are provided.
Three grooved rollers 12 are rotatably supported between them. A large number of grooves are formed on the circumference of the grooved roller 12, and the wires 13 are sequentially wound around each groove to form parallel wire rows. The grooved roller 12 is rotated by a motor (not shown), so that the wire 13 runs at high speed. Further, the abrasive grain liquid is ejected from the abrasive grain liquid supply device (not shown) to the wire 13, and the abrasive grains adhere to the wire 13.

In the work drive unit 20, a column 21 is provided with a linear guide 22, and a moving block 23 is supported by the linear guide 22 so as to be movable in the Z direction. In addition, square groove portions 24 are formed at the two ends of the moving block 23,
Clamp cylinders 25 are provided above the square groove portions 24, respectively.

The processing portion is constructed in this way. First, the slice base 31 made of a material such as carbon is adhered to a part of the outer periphery of the work W, and the mounting plate 32 is further adhered to the slice base 31. Then, when the mounting plate 32 on which the work W is mounted is inserted into the square groove portion 24, the mounting plate 32 is fixed by the clamp cylinder 25.

After the work W is mounted in this way, when the starting operation is performed, the wire 13 runs at high speed in the Y direction, the moving block 23 moves in the Z downward direction, and the work W is moved from the side where the slice base 31 is not adhered. It will be cut. The cutting is completed when the work W is completely cut and a part of the slice base 31 is cut.

Next, when the cutting of the work W is completed, the moving block 23 moves in the Z upward direction and the thin plate-shaped portion Wa is extracted from the wire 13. And work W
Is taken out together with the mounting plate 32, and the slice base 31 is separated from the work W by another device. When the slice base 31 is peeled off, the thin plate-shaped portions Wa are separated one by one. Those separated one by one (hereinafter referred to as "wafers") serve as substrates for semiconductor elements. However, both end portions of the work W are generally not used. In addition,
Peeling of the slice base 31 is generally performed by putting the work W in hot water (about 100 °) to soften the adhesive between the work W and the slice base 31.

[0009]

However, the conventional method requires a dedicated peeling device for peeling the slice base 31, and the peeling takes time.
Further, the adhesive may remain on the wafer even if the slice base 31 is peeled off. Further, there is a problem that the wafer may be damaged when the slice base 31 is peeled off or when the remaining adhesive is removed.

The present invention has been made in view of the above circumstances, and a work holding device for a wire saw, in which a slice base 31 is inserted into a work W to attach a mounting plate 32, and the mounting plate 32 is mounted on a moving block 23. In the above, it is an object of the present invention to provide a work holding device that does not require a special peeling device, can perform the peeling of the slice base 31 in a short time, and does not cause the adhesive to remain on the wafer.

[0011]

According to the present invention, in order to achieve the above object, the work W and the slice base 31 are joined by ice. That is, the work holding device for the wire saw is configured as follows. (A) The moving block 23 is provided with the internal refrigerator 26. (B) An external refrigerator 35 is provided outside the wire saw. Then, (c) the work W and the slice base 31 are joined with ice by the external refrigerator 35. (D) After attaching the work W to the moving block 23,
Work W and slice base 31 by the internal refrigerator 26
Keep the ice between and frozen. I did it above.

In this case, the slice base 31 may be made of a material such as carbon as in the prior art, but it may be made of ice as follows. That is, (a) A water tank 42 having the same shape as the slice base 31 inside is provided outside the wire saw. (B) The work W is brought into contact with the water stored in the water tank 42, and the external refrigerator 35 freezes the water.

[0013]

1 and 2 show a first embodiment of a work holding device for a wire saw according to the present invention. FIG. 1 is a front view and FIG. 2 is a sectional view taken along the line AA of FIG. 1, both of which represent a part of the processed portion of the wire saw. The major features of the work holding device according to the present invention are the work W and the slice base 3
Since the joining with No. 1 is performed by ice, the basic structure of the work holding device may be almost the same as the contents described in the related art.

As shown in FIGS. 1 and 2, the work holding device according to the present invention is different from the work holding device described in the related art.
An internal refrigerator 26 and a support cylinder 27 for driving it in the Z direction are provided in the vicinity of the square groove portion 24 at the tip of the moving block 23.
Is different from that of the wire saw as shown in FIG. 3 except that the external refrigerator 35 is provided outside the wire saw. A thermocouple element (also called a Peltier element) is built in each of the internal refrigerator 26 and the external refrigerator 35. The thermocouple element absorbs calories from one side and discharges it to the other side when a direct current is applied.
2) is cooled below 0 ° and heat is generated on the other side. Cooling water is circulated (not shown) on the side where heat is generated and cooled.

In the work holding device thus constructed, the work W is mounted on the wire saw as follows. First, as shown in FIG. 3, a slice base (material such as carbon) 31 to which a mounting plate 32 is previously attached is placed on an external refrigerator 35, water is supplied to the upper surface of the slice base 31, and then the work W Put. Then, the water on the upper surface of the slice base 31 is frozen into ice by the external refrigerator 35, and the work W and the slice base 31 are joined.

Next, the mounting plate 3 on which the work W is mounted
When 2 is inserted into the square groove portion 24, the mounting plate 32 is fixed by the two clamp cylinders 25, and the internal refrigerator 26 descends until it comes into contact with the mounting plate 32 by the support cylinder 27. Then, the internal refrigerator 26 freezes and maintains the ice generated between the work W and the slice base 31 via the mounting plate 32 and the slice base 31.

After the work W is mounted in this way, when the starting operation is performed, the wire 13 travels in the Y direction at high speed and the moving block 23 moves downward in the Z direction to cut the work W, as in the prior art. . When the cutting of the work W is completed, the moving block 23 moves in the Z upward direction and the thin plate-shaped portion Wa is extracted from the wire 13, and the work W is taken out together with the mounting plate 32.

The work W taken out together with the mounting plate 32 is left outside or put in hot water to melt the ice generated between the work W and the slice base 31, The slice base 31 is peeled off and the wafers are separated one by one. In this case, although the slice base 31 and the mounting plate 32 are bonded to each other in advance with an adhesive or the like, a method of bonding them with ice may be used.

Next, a second embodiment of the work holding device for a wire saw according to the present invention will be described. This method differs from Embodiment 1 described above only in the slice base 31. That is, as shown in FIG. 4, a water tank 42 is provided in addition to the external refrigerator 35 provided outside the wire saw.

In FIG. 4, the inner dimensions of the water tank 42 are the same as the outer dimensions of the slice base 31 described above. Therefore, when the water W is filled in the water tank 42 and the work W is placed on it (a part of the water 41 overflows), it is placed on the external refrigerator 35, and the water 41 is frozen by the external refrigerator 35. , The same shape as the slice base 31 is generated with ice.

Next, when the freezing of the external refrigerator 35 is stopped and the water tank 42 is slightly warmed (the direction of the current to the thermocouple element built in the external refrigerator 35 is changed), the inner wall of the water tank 42 is changed. Slice base 4 produced by melting the ice in the part
1a can be taken out in a state of being bonded to the work W.

Further, the water tank 42 is removed from the external refrigerator 35, the mounting plate 32 is placed, and the slice base 4 is placed thereon.
1a is mounted and the attachment plate 32 is frozen by the external refrigerator 35. As a result, the mounting plate 32 and the slice base 41a
Since and are joined, as in the first embodiment described above,
The mounting plate 32 is attached to the square groove portion 24. Then, by the internal refrigerator 26, the slice base 41 is attached via the mounting plate 32.
a is continuously frozen, the slice base 41a itself is maintained, and the joint between the mounting plate 32 and the work W is maintained.

After this, similarly to the first embodiment, when the cutting is completed, the work W is taken out together with the mounting plate 32. Then, the slice base 41a is thawed by being left outside or put in hot water, and the joining between the work W and the slice base 41a is released,
Wafers are separated one by one.

In the above-described embodiment, an example in which the work W is moved downward in the Z direction and cut by the wire saw is shown. However, the vertical relationship between the wire drive unit 10 and the work drive unit 20 is shown. Can be applied to a wire saw in which the work W is moved in the Z upward direction to cut the work. Further, although the holding structure of the mounting plate 32 of the moving block 23 is a square groove and is mounted in the Y direction, a dovetail groove may be used instead of the square groove, or a holding structure may be mounted in the X direction. Further, the refrigerating means of the internal refrigerator 26 and the external refrigerator 35 is not limited to the thermocouple element, and may be a refrigerating cycle.

[0025]

As described above, in the work holding device for the wire saw according to the present invention, the work W and the slice base 31 are joined by ice. Further, in this case, the slice base 31 is made of ice in addition to the method of making a material such as carbon as in the conventional technique. Therefore, it is possible to provide a work holding device that does not require a special peeling device, can perform the peeling of the slice base 31 in a short time, and does not cause the adhesive to remain on the wafer. Further, if the slice base 31 is made of ice, a material such as carbon becomes unnecessary, and the processing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a part of a processing portion of a first embodiment of a work holding device according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a use state diagram of the external refrigerator of the first and second embodiments of the work holding device according to the present invention.

FIG. 4 is a slice base generation state diagram of the second embodiment of the work holding device according to the present invention.

5 is a configuration diagram of a processing portion of a general wire saw (a front view, corresponding to a cross section taken along line CC of FIG. 6).

FIG. 6 is a sectional view taken along line BB of FIG. 5;

[Explanation of symbols]

 23 ... Moving block 24 ... Square groove 25 ... Clamp cylinder 26 ... Internal refrigerator 27 ... Support cylinder 31 ... Slice base 32 ... Mounting plate W ... Work Wa ... Thin plate-shaped part

Claims (2)

[Claims] 1. A wire comprising a plurality of wires, which are provided in parallel with each other in the X direction and have a high speed running in the Y direction, to which abrasive grains are attached, and a moving block which holds the work and is movable in the Z direction. Z of the work in a wire saw that cuts the work into a thin plate by pressing
In a work holding device that attaches a mounting plate with a slice base inserted in the direction surface and attaches the mounting plate to the moving block, an internal refrigerator is provided in the moving block, and an external refrigerator is provided outside the wire saw. After the work and the slice base are joined with ice by the external refrigerator and the work is attached to the moving block, the ice between the work and the slice base is kept cooled by the internal refrigerator. Wire saw work holding device. 2. A water tank having the same shape as the slice base inside is provided outside the wire saw, and the work is brought into contact with the water stored in the water tank, and the water is frozen by the external refrigerator to obtain the slice base. The work holding device for a wire saw according to claim 1, wherein the work piece is made of ice.