JP3166742B2 - Dicing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing apparatus, and more particularly, to a dicing apparatus that recognizes a shape of a semiconductor wafer as a workpiece and sets a cutting area and the like based on the shape.

[0002]

2. Description of the Related Art Conventionally, there has been known a dicing apparatus which sequentially transports a workpiece from a cassette containing a plurality of workpieces such as semiconductor wafers to a cutting section by a transport mechanism and cuts the workpiece into a predetermined shape. Further, in such a dicing apparatus, there is known a dicing apparatus in which a workpiece is imaged by a video camera or the like using a two-dimensional sensor, and the image data is processed to recognize the shape of the workpiece. The shape of the work is, for example, usually circular when the work is a silicon wafer, but is not necessarily circular.
There are some squares and those that break in the process before dicing and become irregular. Therefore, as described above, by recognizing the shape of the work by imaging the work with the camera, the cutting area is limited according to the shape of the work to reduce unnecessary cutting operations, and the work having the desired shape can be efficiently and quickly performed. It can be processed with.

[0003]

However, as the size of the work increases, the camera must be installed far away from the work in order to image the entire work.
There is a problem that a space required for a system for recognizing a work shape becomes large. Then, a problem has arisen that the size of the entire apparatus is increased accordingly.

[0004] In addition, if an attempt is made to capture the entire work by shortening the distance between the camera and the work, an expensive lens such as an ultra-wide-angle lens is required, and the image is distorted in addition to the problem of high cost. As a result, there is a problem that the workpiece shape cannot be recognized accurately. In particular,
Since the diameter of a semiconductor wafer has been increased in recent years, it is an important issue to solve such a problem in a dicing apparatus for cutting a silicon wafer into chips.

[0005] The present invention has been made in view of such circumstances, and has as its object to provide a dicing apparatus capable of accurately and efficiently recognizing the shape of a work and realizing miniaturization of the apparatus. .

[0006]

According to the present invention, in order to achieve the above object, the present invention conveys a work from a storage section in which the work is stored to an alignment section by a transfer means, and images the work by the alignment section. In a dicing apparatus that aligns the work and cuts the work at a cutting unit, a line scanner separate from an imaging unit of the alignment unit is provided on a conveyance path until the work is conveyed to the alignment unit by the conveyance unit. Is installed, and the line scanner captures an image of the work while the work is moving along the transport path, and detects the shape of the work.

According to the present invention, the work is imaged by a line scanner using a one-dimensional sensor instead of a video camera using a two-dimensional sensor. Is prevented. Further, since the line scanner is provided on the transport path on which the workpiece is transported, no special time and space are required for imaging the workpiece, so that the processing time can be reduced and the apparatus can be downsized. Further, since it is not necessary to use a wide-angle lens or the like, distortion or the like does not occur in the acquired image, and the shape of the work can be accurately recognized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A dicing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of a semiconductor wafer dicing apparatus to which the present invention is applied, and FIG. 2 is a plan view thereof. As shown in FIG. 1, the dicing apparatus 1 mainly includes a cutting unit 10 and a cleaning unit 2.
0, a cassette storage unit 30, an elevator unit 40, a transport device 50, and the like.

The process of cutting the wafer W by the dicing apparatus 1 will be described. First, a plurality of unprocessed wafers W stored in the cassette storage unit 30 are sequentially pulled out by the elevator unit 40 and then drawn out. The wafer W is set at the position P4 shown in FIG. still,
As shown in FIG. 2, the wafer W is bonded to the frame F. Next, the wafer W is transferred to the preload stage at the position P1 by the transfer means of the elevator unit 40 (this transfer means will be described later), and thereafter, the cutting table (position P2) of the cutting unit 10 by the transfer device 50. Placed on top. Here, the wafer W is held by suction on the cutting table. The wafer W held by suction is transferred to the wafer W by the alignment unit 18.
The upper pattern is image-recognized and aligned based on this. Then, the aligned wafer W
The two streets are cut at the same time by the movement of the cutting unit 10 in the Y-axis direction indicated by arrows A and B and the movement of the cutting table in the X-axis direction indicated by arrows C and D. When the first two streets are cut, the spindle of the cutting section 10 is moved by one street pitch in the Y-axis direction, and the cutting table is moved again in the X-axis direction. As a result, the next two streets are cut. This cutting operation is repeatedly performed, and when the cutting of all the streets in one direction (X direction) is completed, the cutting table is rotated by 90 ° and the other direction orthogonal to the cut street (the Y direction in FIG. 2). ) Is cut sequentially. Thereby, the wafer W is finally cut into a dice and divided into chips.

After the cut wafer W is returned to the position P2 by the cutting table, the transfer device 50
Is transported to the spinner table of the cleaning unit 20 at the position P3. Here, the wafer W is dried by the air blow after being washed with the washing water. The dried wafer W is transferred to the position P4 by the transfer device 50, transferred to the cassette unit 30 by the elevator unit 40, and stored in a predetermined cassette. The above is the flow of the process of cutting one wafer W by the dicing machine 1.

As shown in FIG. 2, the cutting section 10 of the dicing machine 1 has a pair of cutting devices 14 and 16, and the cutting devices 14 and 16 include motors 60 and 62 and a spindle 6
4, 66, and blades 68, 70 mounted on the tips of the spindles 64, 66. The cutting device 1
4 and 16 are independently moved in the Y-axis direction by a spindle moving mechanism. In the present embodiment, a linear motor is applied as the spindle moving mechanism. The principle and the detailed structure of the linear motor are well known and will not be described here.

On the other hand, as shown in FIG. 1, the cassette accommodating section 30 of the dicing machine 1 has a four-stage structure, and includes inspection stages (dummy wafer accommodating section: single-wafer processing wafer accommodating section) 32 in order from the top. It comprises a first cassette storage section 34, a second cassette storage section 36, and a utility cassette storage section 38. The first and second cassette storage sections 34 and 36 are storage sections for storing normal cassettes. The cassettes stored in these cassette storage sections 34, 36 are provided with respective doors 35, 3
By opening the doors 35, 37 with the handles 35A, 37A provided on the 7, the user can take it out of the dicing machine body. The normal cassette is a large cassette in which a large number of wafers of the same model number are stored. However, since the dicing apparatus 1 can recognize the shape of the wafer before cutting, as described later, it is possible to appropriately cut the wafer even when wafers having different shapes, for example, cracked wafers and the like are mixed. It is.

Next, a line scanner for recognizing the shape of a wafer will be described. Normal wafer W is
It is formed in a substantially circular shape (a part is formed with an orientation flat or a notch-shaped notch). However, the shape is not always such a shape, and there are a square shape, a cracked broken wafer, and the like. Therefore, by recognizing the shape of the wafer before cutting the wafer, the alignment of the wafer and the setting of the cutting area of the wafer can be appropriately performed according to the shape of the wafer. In the dicing apparatus according to the present invention, for example, as shown in FIG. 3, a one-dimensional sensor (C) is provided between the position P4 of the elevator unit 40 and the position P1 of the preload stage.
A line scanner 100 using a CD line sensor) is installed, and an image of the wafer W is taken when the wafer W passes over the line scanner 100 in the process of transporting the wafer W. Thereby, the shape of the wafer W can be accurately recognized. Further, by using a line scanner, the space of the shape recognition system can be made more compact than a video camera using a two-dimensional sensor, and the entire apparatus can be made smaller. It is beneficial from the viewpoint of effective use of the clean room if the entire apparatus is reduced in size. Note that the line scanner 100 may be of a reflection type (integrated projection / reception type) or a transmission type (separated projection / reception type).

The specific installation position of the line scanner 100 will be described. For example, the end of the elevator unit 40 is preferable. 4 and 5 are a plan view and a side view showing the configuration of the elevator unit 40 in which the line scanner 100 is installed. As shown in these figures, an elevator column 102 is disposed in the elevator section 40 in a vertical direction, and a guide block 104 is engaged with the elevator column 102 so as to be able to move up and down. The guide block 104
Is fixed to a U-shaped frame 106,
The frame 106 has a rectangular support plate 108.
Are fixed in a direction perpendicular to the lifting column 102, that is, in a horizontal direction.

A motor 110 is mounted on the support plate 108, and a pulley 114 is provided on a shaft 112 of the motor 110. An endless belt 116 is wound around the pulley 114,
The belt 116 is stretched by the pulley 114 and the pulley 118. A connecting member 120 is fixed to the belt 116 as shown in FIG.
The finger part 122 is fixed to 20. The finger portion 122 is slidably engaged with a guide rail 124 provided in parallel with the belt 116 via a guide block 126. Accordingly, when the motor 110 is driven and the belt 116 is moved, the finger portion 122 is moved within a range between a take-out position indicated by a solid line in the drawing and a draw-out position indicated by a two-dot chain line. By the operation of the finger portion 122, the wafer W stored in the cassette storage portion 30 is taken out, and the taken-out wafer W is placed on the mounting plates 128, 128 provided on the support plate 108, and the rail 130, It is placed on 130. These mounting plates 128, 128,
And the rails 130 and 130 respectively
The wafer W is mounted on the mounting plates 128, 128 and the rails 130, 130 by a wafer opening operation after the finger portion 122 is moved to the pull-out position. The mounting plate 1
The rails 28, 128 and the rails 130, 130 support the frame F to which the wafer W is bonded.

When the wafer W is taken out of the cassette accommodating section 30 into the elevator section 40 in this manner, next,
The elevator section 40 rises to the upper end position of the lifting column 102. Then, the wafer W is transported to the position P1 of the preload stage again by the operation of the finger unit 122. The line scanner 100 is installed at the front end of the mounting plate 128 perpendicularly to the transfer direction of the wafer W as shown in FIGS. When taking out the wafer W from the cassette storage section 30 to the elevator section 40 as described above, or
From the mounting plate 128 to the position P1 of the preload stage
Is transferred to the line scanner 1
Pass above 00. The line scanner 100 captures an image of the wafer W while the wafer W is passing above,
An image of the entire wafer W is acquired. By setting the line scanner 100 at the end of the elevator unit 40 in this manner, the shape of the wafer W can be recognized together with the transfer of the wafer W, so that a special time or space for recognizing the shape of the wafer W is required. It is not necessary, and the processing time can be reduced and the size of the apparatus can be reduced. Incidentally, the imaging process of the wafer W
The wafer W is moved from the cassette storage section 30 to the elevator section 40.
May be taken out, or may be carried from the mounting plate 128 to the position P1 of the preload stage.

FIG. 6 is a right side view of the dicing apparatus W, showing an example of a position where the line scanner can be installed. When the line scanner is installed at the end of the elevator unit 40 as described above, the position indicated by reference numeral 150 in FIG. As a position where the line scanner can be installed other than the elevator unit 40, the end 152 of the preload stage, the wafer outlet 154 of the inspection stage 32, or the like can be used as shown in FIG.
In addition, a line scanner can be installed at a desired transfer path on which the wafer W is transferred at a position other than the position shown in FIG. However, when the transfer path of the wafer W is not linear, or when the line scanner is installed at a position where the wafer moves while rotating during the transfer, it is necessary to correct the image acquired by the line scanner.

It is also possible to image the wafer W by moving the line scanner at a constant speed. For example,
As shown by reference numeral 156 in the figure, a line scanner is installed movably in the direction of arrow 158 above the preload stage, and the line scanner scans the wafer W at a constant speed on the wafer W stationary on the preload stage. It is also possible to obtain the entire image. Also, the wafer W
It is also possible to take an image of the wafer W by moving the line scanner at another position (e.g., the elevator unit 40, on the cutting table, etc.) where the camera is stationary.

Next, the control of the control unit of the dicing apparatus after recognizing the shape of the wafer as described above will be briefly described. For example, when cutting a broken wafer W ′ as shown in FIG. 7, when the broken wafer W ′ passes over the line scanner 100,
As a result, an image of the cracked wafer W ′ is obtained. The control unit accurately recognizes the shape of the broken wafer W ′ based on the image. Next, the broken wafer W ′ is transported to the cutting table, and the pattern on the broken wafer W ′ is imaged by the alignment unit 18. Then, the position where the predetermined pattern is formed is detected at a plurality of locations.
At this time, since the control unit has already recognized the shape of the broken wafer W ', the detection position of the predetermined pattern on the broken wafer W' is within the range of the broken wafer W 'as shown in FIG. The position can be selected as close as possible to the center position A and the positions B to E separated from the left, right, up and down, that is, the positions close to the contour of the broken wafer W ′. As described above, since the pattern detection position can be reliably set within the range of the broken wafer W ′, it is possible to prevent an alignment error due to the inability to detect the pattern. Further, by detecting patterns at a plurality of positions as far apart as possible within the range of the cracked wafer W ′, highly accurate alignment can be performed.

When the alignment is completed in this manner, the cutting process of the cracked wafer W 'is performed next. At this time, since the control unit accurately recognizes the outer shape of the cracked wafer W', the cutting area is set. Can be set to a minimum. That is, when the cutting table is moved to the left and right to cut the broken wafer W ′ by the blades 68 and 70 (see FIG. 2), the feed range of the broken wafer W ′ is set to the position of the blades 68 and 70. It can be limited to the range that exists. This can save unnecessary time for cutting a position where the broken wafer W ′ does not exist, thereby shortening the processing time.

In the above embodiment, the dicing apparatus for cutting a semiconductor wafer has been described. However, the present invention is not limited to this, and the present invention can be applied to a dicing apparatus for cutting a desired work.

[0022]

As described above, according to the dicing apparatus according to the present invention, the work is imaged not by a video camera using a two-dimensional sensor but by a line scanner using a one-dimensional sensor. However, the problem that the apparatus becomes large is prevented. That is, 2
In a video camera using a dimensional sensor, when the work becomes large, the camera needs to be far away from the work in order to image the entire work. Even if it is large, it is not necessary to increase the distance from the work, and the space for recognizing the shape of the work can be reduced.

In order to reduce the space when photographing a workpiece with a video camera, it is necessary to use an ultra-wide-angle lens or the like. Therefore, the captured image may be distorted or may be corrected to correct the distortion. The system and high-precision optical system lens were required, which was costly.However, using a line scanner solved such problems, and it became possible to recognize workpiece shapes with high accuracy using inexpensive equipment. Become.

Further, since the line scanner is provided on the transporting path on which the workpiece is transported, no special time and space are required for capturing the workpiece, the processing time can be reduced, and the apparatus can be downsized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a dicing apparatus to which the present invention is applied.

FIG. 2 is a plan view of the dicing apparatus shown in FIG.

FIG. 3 is an explanatory view used for explaining a line scanner used for shape recognition of a wafer;

FIG. 4 is a plan view showing a configuration of an elevator unit.

FIG. 5 is a side view showing a main part of the elevator part, omitting details.

FIG. 6 is a diagram illustrating an installation position of a line scanner.

FIG. 7 is a diagram illustrating an example of a broken wafer.

FIG. 8 is a diagram showing an example of a pattern detection position of a broken wafer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dicing apparatus 10 ... Cutting part 40 ... Elevator part 90 ... Camera 100 ... Line scanner W ... Wafer

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/301 H01L 21/68

Claims (2)

(57) [Claims] A transfer means for transferring the work from a storage section in which the work is stored to an alignment section;
Align the work by imaging the work
And, in the dicing device for cutting the workpiece by the disconnected portion, the alignment portion and the workpiece by the conveying means
Of the alignment unit on the transport path until it is transported to
A dicing apparatus, further comprising a line scanner provided separately from an imaging unit , wherein the line scanner captures an image of the work while the work is moving along the transport path, and detects a shape of the work. 2. The line scanner according to claim 1, wherein the line scanner is installed in a transport unit that takes out the work from a storage unit in which the work is stored, and transports the work to a predetermined position. The dicing apparatus according to claim 1, wherein the work is imaged by the line scanner when the work is transported to the predetermined position.