JP2000058489A - Work dividing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ground particles from adhering to a work, to protect the work against chipping, and to improve a work dividing device in dividing efficiency by a method wherein a dividing region of the work is heated by a laser beam, and then a flow of cold air is made to blow against the dividing region of the work to divide it at its dividing region. SOLUTION: A laser beam irradiating means 23 that irradiates a wafer W with a laser beam and a cold air spouting means 24 that blows cold air against a wafer W as a work are arranged in a dividing region 25. When the wafer W is divided at a dividing region, a chuck table 14 is moved blowing cold air against the wafer W by the cold air spouting means 24 while the wafer W is irradiated with a laser beam by the laser beam irradiating means 23. By this setup, the dividing region of the wafer W that is expanded by heating is cooled down and shrunk, and a strain is induced in the wafer W by shrinkage to divide the wafer W at the breaking region. Therefore, a wafer dividing device can be improved in dividing efficiency. Furthermore, a dividing process is carried out in a dry manner, so that ground particles are prevented from adhering to the wafer W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor wafer,
The present invention relates to a dividing method and a dividing apparatus for dividing a workpiece such as glass into predetermined sizes and shapes.

[0002]

2. Description of the Related Art A dicing apparatus is generally used for dividing a workpiece such as a semiconductor wafer.
In this case, as shown in FIG. 9, the semiconductor wafer 40 is held by the chuck table 41, and the rotating blade 42 that rotates at a high speed while the chuck table 41 moves in the X-axis direction cuts into the semiconductor wafer 40. 40 is cut and divided. At this time, cutting water for cooling the contact portion between the rotary blade 42 and the semiconductor wafer 40 is supplied from the cutting water supply means 43, and cutting water mixed with cutting chips (contamination) is removed. The washing water is jetted from the washing water jetting means 44.

[0003]

However, the cleaning water jetted from the cleaning water jetting means 44 does not always completely remove the contamination, and the unremoved contamination causes the surface of the semiconductor wafer 40 to be removed. If there is a drift, there is a problem in that the drifted contamination adheres to and contaminates the chips divided individually by cutting, thereby deteriorating the quality of the chips.

Further, since cutting is performed while crushing the workpiece by the rotating blade 42, irregular chips called chipping are apt to occur on both sides of the cutting groove formed by cutting, which also lowers the quality of the chip. Contributes.

Furthermore, since the movement (cutting feed) of the chuck table 41 in the X-axis direction is relatively slow, there is a problem that the dividing efficiency is not good.

[0006] Therefore, in the case of dividing the workpiece, it is possible to solve the problem of not reducing the quality of the divided product due to the attachment of crushed particles such as contamination and the occurrence of chipping of irregular shapes, and increasing the dividing efficiency. Have issues to be addressed.

[0007]

As a specific means for solving the above-mentioned problems, the present invention relates to a method for dividing a workpiece, wherein the area to be divided of the workpiece is irradiated with a laser beam. Provided is a method for dividing a workpiece, which comprises at least a laser beam irradiation step of heating an area to be heated and a cutting step of blowing a cold air onto the area heated by the laser beam irradiation step to cut the workpiece.

[0010] Then, following the laser beam irradiation in the laser beam irradiation step, a cold air is blown to the heated area immediately after heating to perform the cutting step. The workpiece is a semiconductor wafer, and the area to be divided is It is an additional requirement that the object be a street and that a plurality of regions to be divided intersect in the X-axis direction and the Y-axis direction on the workpiece.

The present invention also provides a chuck table for holding a workpiece, a laser beam irradiating means for irradiating the workpiece held on the chuck table with a laser beam,
There is provided a dividing device including at least a cool air jetting unit that blows cold air onto a region irradiated with a laser beam.

A street is formed on the workpiece as an area to be divided. The street is aligned with the laser beam emitted from the laser beam irradiating means. That the laser beam is radiated by the laser beam irradiating means, the cold air blowing means blows cold air to the area to be divided, and the chuck table moves in the X-axis direction. It is an additional requirement that the laser beam irradiation means and the cold air jetting means be indexable and movable in the Y-axis direction.

According to the method and the apparatus for dividing a workpiece, the workpiece is heated by irradiating a laser beam and then blown with cool air, whereby the workpiece is distorted and thereby cut. Therefore, the division efficiency is higher than in the conventional cutting.

Furthermore, since the division is performed in a dry manner without using cutting water as in the prior art, there is no possibility that crushed particles adhere to the workpiece and become contaminated. Further, although a laser beam is used in the present invention, the workpiece is not heated so as to be melted by the laser beam, so that the melted droplets are not attached and contaminated.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, FIG.
1 and a method of dividing a semiconductor wafer using the dividing device 10 will be described as an example.

For example, when the semiconductor wafer W is to be divided using the dividing device 10 shown in FIG. 1, the semiconductor wafer W is held by the frame F via the holding tape T and stored in the cassette 11 in a plurality of layers. Is done.

Semiconductor wafer W held by frame F
Is carried out of the cassette 11 by the carrying-in / out means 12, is placed in the temporary storage area, is sucked by the carrying means 13, is carried to the chuck table 14 by its turning motion, is placed, and is suction-held.

As shown in FIG. 2, the chuck table 14
Is rotatably supported by the support table 15 and driven by a first motor 16 provided below the support table 15 to be rotatable (θ-indexed rotation). A base 17 provided with a first motor 16 at the upper portion is slidably engaged with a pair of guide rails 18 and screwed to a first ball screw 19 provided in the X-axis direction. ing. Then, as the first ball screw 19 is rotated by being driven by the second motor 20, the support table 15 and the chuck table 14 are also movable in the X-axis direction with the expansion and contraction of the bellows 21.

The semiconductor wafer W is placed on the chuck table 14
The chuck table 14 moves in the X-axis direction and is positioned immediately below the alignment means 22. The area to be divided is detected by processing such as pattern matching, and the area to be divided and the laser beam irradiating means 23 are detected. Beam and cold air jetting means 24 irradiated from outside
Is adjusted in the Y-axis direction with the cool air blown out of the air. When the positioning is performed in this manner, the chuck table 14 further moves in the X-axis direction and enters the divided area 25.

In the divided area 25, a laser beam irradiating means 23 for irradiating a laser beam to a workpiece and a cool air blowing means 24 for blowing a cool air to the workpiece are provided. As shown in FIG. 3, the laser beam irradiation unit 23 and the cool air injection unit 24 protrude downward from the tip of the common base 26, and the base 26 is provided vertically along the wall 27. It is integrated with a support portion 29 screwed to the second ball screw 28. Then, the second ball screw 28 rotates by being driven by the third motor 30, and the supporting portion 29 moves up and down accordingly, so that the laser beam irradiation means 23 and the cold air jetting means 24 also move up and down, that is,
It is movable in the Z-axis direction. The movement of the laser beam irradiating means 23 and the cool air jetting means 24 in the Z-axis direction is precisely controlled based on the value measured by the linear scale 31. Preferably, the laser beam irradiating means 23 and the cool air jetting means 24 are configured so that the distance between them can be adjusted.

Further, the wall 27 is erected from the end of the base 32, and the base 32 is screwed into the second ball screw 33. The rotation of the base 33 causes the base 32 to move in the Y-axis direction, whereby the laser beam irradiation means 23 and the cool air jetting means 24 move (index movement) in the Y-axis direction. Then, the movement of the two in the Y-axis direction is precisely controlled based on the measured value by the linear scale 35.

As shown in FIG. 4, on the surface of the semiconductor wafer W, there are a plurality of linear regions S, which are arranged in a grid at predetermined intervals. The rectangular area is provided with a circuit pattern. Then, by dividing the street S, the street S is divided into respective rectangular areas, each of which becomes a chip.
That is, the area to be divided on the semiconductor wafer W is the street S.

In cutting the street S,
Already street S and laser beam by alignment
Y-axis direction with laser beam irradiated from irradiation means 23
Since the alignment of the position has been performed, as shown in FIG.
X of the chuck table 14_L While moving in the direction
High energy and good directivity from the laser beam irradiation means 23
When the laser beam is irradiated, the street S is heated
Expands.

Further, in parallel with the irradiation of the laser beam, cool air is blown from the cool air injection means 24. Since the laser beam irradiating means 23 and the cool air jetting means 24 are arranged at the same position in the Y-axis direction and are arranged at a fixed distance in the X-axis direction, for example, the area 36 in FIG. When it is, cold air is blown to the area 37.

In this way, when cold air is blown in parallel with the irradiation of the laser beam, the region is positioned at a position where the cool air is blown immediately after heating by the movement of the chuck table 14, and the region expanded by heating is immediately cooled. Street S contracts. When the street S shrinks as described above, a strain is generated. The strain causes the street S to be cut along the cutting line 38, for example.

Each time one street S is cut, the laser beam irradiating means 23 and the cold air jetting means 24 are indexed and sent in the Y-axis direction by the street interval, and the same cutting is repeated, whereby the street in the X-axis direction is repeated. S
Are all cleaved.

After all the streets S in the X-axis direction have been cut in this manner, the chuck table 14 is indexed and rotated by 90 degrees and cut in the same manner as described above, whereby the streets S are cut vertically and horizontally and divided into individual chips. Is done.

As described above, since the workpiece is heated by irradiating the laser beam, the workpiece is heated and then cooled by blowing cool air to cut and divide the workpiece.
It can be moved quickly in the axial direction. Therefore, the division efficiency is higher than in the conventional case of cutting, and the productivity can be improved.

Further, since the division is carried out in a dry manner, the crushed particles do not adhere to the workpiece and become contaminated, and the quality of the divided product is not reduced. Furthermore, because it is not a method of fusing the workpiece with a laser beam,
There is no possibility that the melted droplets adhere and become contaminated.

[0028]

As described above, according to the method and apparatus for dividing a workpiece according to the present invention, the workpiece is heated by irradiating a laser beam and then blown with cool air to thereby deform the workpiece. Is generated and cut by this, so that the division efficiency is higher and the productivity can be improved as compared with the conventional case of cutting.

Further, since the division is performed in a dry manner without using cutting water as in the prior art, there is no possibility that crushed particles adhere to the workpiece and become contaminated, and the quality of the divided product is reduced. I will not let you. In addition, although a laser beam is used in the present invention, the workpiece is not heated so as to be melted by the laser beam, so that the melted droplets are not attached and contaminated, and the quality of the divided product is reduced. Nothing.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a dividing device according to the present invention.

FIG. 2 is a perspective view showing a mechanism for driving a chuck table of the dividing device.

FIG. 3 is an explanatory diagram showing a mechanism for driving a laser beam irradiation unit and a cool air injection unit of the splitting device.

FIG. 4 is a plan view showing a surface of a semiconductor wafer cut by the dividing device.

FIG. 5 is an explanatory view showing a state in which a semiconductor wafer is cut by the dividing device.

FIG. 6 is a plan view showing a surface of a semiconductor wafer cut by the dividing device.

FIG. 7 is a perspective view showing a state of cutting a semiconductor wafer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Dividing device 11 ... Cassette 12 ... Carry-in / out means 13 ... Transport means 14 ... Chuck table 15 ... Support table 16 ... First motor 17 ... Base 18 ... Guide rail 19 ... First ball screw 20 …… Second motor
21 bellows 22 alignment means 23 laser beam irradiation means 24 cold air jetting means 25 divided area 26 base 27 wall 28 second ball screw 29 support 30 Third motor 31 Linear scale 3
2 ... Base 33 ... Second ball screw 34 ... Fourth motor
35 linear scale 36, 37 area 38 cutting line W semiconductor wafer T holding tape F frame S street 40 semiconductor wafer 41 chuck table
42 rotating blade 43 cutting water supply means 44 washing water injection means

Claims (8)

[Claims] 1. A method for dividing a workpiece, comprising: irradiating a laser beam to a region to be divided of the workpiece to heat the region to be divided; and heating the laser beam by the laser beam irradiating step. And cleaving the workpiece by blowing cold air onto the region. 2. The method for dividing a workpiece according to claim 1, wherein, following the irradiation of the laser beam in the laser beam irradiating step, the cutting step is performed by blowing cold air on the heated area immediately after heating. 3. The method according to claim 1, wherein the workpiece is a semiconductor wafer, and a region to be divided is a street. 4. The method of dividing a workpiece according to claim 1, wherein a plurality of regions to be divided cross each other in the X-axis direction and the Y-axis direction on the workpiece. . 5. A chuck table for holding a workpiece, a laser beam irradiating unit for irradiating a laser beam to the workpiece held on the chuck table, and a cool air jetting unit for blowing cool air to an area irradiated with the laser beam. A splitting device comprising at least: 6. A street is formed on a workpiece as a region to be divided, and the street is aligned with a laser beam irradiated from a laser beam irradiating means, and the street and the cold air blown from a cool air jetting means. 6. The dividing device according to claim 5, further comprising an alignment unit for performing alignment with the image forming apparatus. 7. A cooling air blow means blows cold air onto a region to be divided which is heated by being irradiated with a laser light by a laser light irradiation means, thereby performing cutting.
A splitting device according to claim 1. 8. The chuck table according to claim 5, 6 or 7, wherein the chuck table is movable in the X-axis direction and is rotatable by θ indexing, and the laser beam irradiating means and the cold air jetting means are indexable and movable in the Y-axis direction. The dividing device as described.