JPH0837168A - Method and apparatus for dicing semiconductor wafer - Google Patents

Abstract

PURPOSE:To cut a chip whose edge has been removed uniformly by a method wherein a V-shaped groove is made in the surface of a semiconductor wafer, the width of the V-groove is detected and the interval between a blade and the surface of the wafer is controlled in such a way that the width of the V- groove is within a prescribed range. CONSTITUTION:A semiconductor wafer 11 in which a scribing line has been drawn on the surface is vacuum-chucked to a wafer fixation table 13. The surface of the semiconductor wafer 11 is moved in the X-axis direction and the Y-axis direction along the scribing line so as to make a V-groove while a blade for V-groove formation is being turned. The width of the V-groove is imaged by a CCD camera 20, it is input to, and detected by, a computer 22 so as to judge a permissible range. When the width of the V-groove is deviated from a prescribed range, the interval between the wafer fixation table 13 and the blade for V-groove formation is adjusted and controlled by a controller 23. The blade for V-groove formation is replaced by a blade 12 for cutting, and the semiconductor wafer 11 is cut along the V-groove which has been fored before.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing method and apparatus for dividing a semiconductor wafer into a plurality of chips.

[0002]

2. Description of the Related Art An element such as an electronic device, an optical device, or an optoelectronic integrated circuit in which these are combined is formed on a semiconductor wafer, and a dicing apparatus is used to divide the semiconductor wafer into individual devices. . A general dicing device is provided with a wafer fixing table that is movable in the horizontal direction and a dicing blade that can be rotated at a high speed and that is vertically moved with respect to a semiconductor wafer fixed on the wafer fixing table. Under control, the center line of the scribe line formed between the devices was cut by a disc-shaped dicing blade having a rectangular cross section.

By the way, in the die bonding process and the like, the semiconductor chip cut in this way is adsorbed by the collet and conveyed onto the package. At this time, the edge of the semiconductor chip is damaged and the semiconductor element is scratched. There were cases. In order to prevent this, as shown in FIG. 7, a V-shaped groove is first provided on a semiconductor wafer by a disk-shaped dicing blade (hereinafter referred to as V-groove forming blade) 11-A having a V-shaped circumferential cross section (see FIG. 7 (a)), and then cut along a V groove by a disk-shaped dicing blade 11-B having a rectangular cross section (hereinafter referred to as a cutting blade) (FIG. 7).
(B)), a method of forming a semiconductor chip having a tapered edge has been devised.

[0004]

When such a material is used, the width of the V groove fluctuates due to wear of the V-shaped blade, variations in wafer thickness, etc., and if the width is too wide, the semiconductor element is damaged. If the width is too narrow, the edge cannot be tapered, and it is necessary to control the width of the V groove within an allowable range. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a method and an apparatus for dicing a semiconductor wafer by adjusting or controlling the width of the V groove to fall within a predetermined range.

[0005]

A method for dicing a semiconductor wafer according to the present invention forms a V-shaped groove on the surface of the semiconductor wafer and detects the V-groove width so that the V-groove width falls within a predetermined range. It is characterized in that the semiconductor wafer is cut along the V groove.

In the above-mentioned semiconductor wafer dicing method, while forming one V-groove, the periphery of an adjacent V-groove is imaged, its image information is taken in, and the image information is image-processed to obtain the V-shape. The V-groove width is detected by detecting the groove width, or simultaneously forming one V-groove, capturing an image of the periphery of the V-groove, capturing image information thereof, and subjecting the image information to image processing. And

Another method for dicing a semiconductor wafer according to the present invention is to form a V-shaped groove on the surface of the semiconductor wafer, detect the V-groove width, and adjust the V-groove width to fall within a predetermined range. Then, the semiconductor wafer is then cut along the V groove.

In the above-mentioned semiconductor wafer dicing method, a disk-shaped blade having a V-shaped cross section is rotated to form a V-shaped groove on the surface of the semiconductor wafer, or a disk-shaped circular cross-section is formed. The semiconductor wafer is cut by rotating the blade, and the thickness of the blade having a rectangular cross section is smaller than the minimum value of the V groove width.

Further, the semiconductor wafer dicing apparatus according to the present invention has means for forming a V groove on the surface of the semiconductor wafer, cutting means for cutting the semiconductor wafer, and a wafer fixing surface for fixing the semiconductor wafer. A wafer fixing means adapted to adjust a relative position between the wafer fixing surface and the V-groove forming means, and an image pickup means for picking up an image of a semiconductor wafer fixed on the wafer fixing surface and taking in image information thereof. And image processing means for performing image processing on the image information input from the image pickup means to detect the width of the V groove,
A dicing apparatus for a semiconductor wafer, comprising: a control means for inputting a V-groove width detected by the image processing means and controlling a relative position between the semiconductor wafer and the V-groove forming means. The V-groove width is detected, the V-groove width is controlled, and the semiconductor wafer is cut.

[0010]

According to the above construction, the semiconductor wafer dicing method according to the present invention detects the V-groove width and adjusts or controls the interval between the blade and the wafer surface so that the V-groove width falls within the allowable range. Therefore, as compared with other methods, adjustment / control is easier and accurate groove width can be easily obtained.
Therefore, it is possible to cut a chip having a uniform edge. Further, since the semiconductor wafer dicing apparatus according to the present invention has a function of making the groove width within the allowable range while forming the V groove, it is applied even when the thickness of the semiconductor wafer or the like varies. can do.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. FIG. 1 schematically shows a dicing apparatus 10 according to the present invention. The dicing apparatus 10 has a dicing blade (hereinafter abbreviated as a blade) 12 as cutting means for cutting the semiconductor wafer 11, and a wafer fixing table 13 as wafer fixing means for fixing the semiconductor wafer 11. are doing.

The blade 12 is attached to a spindle 16 of a spindle head 15 supported by a support column 14.
The support column 14 is fixed to a bed 17 which is a fixed structure so as to be oriented vertically, and the spindle head 15 is vertically moved along the support column 14. Also,
The main shaft 16 extends in the horizontal direction and is rotated at high speed.

On the other hand, the wafer fixing table 13 is the bed 1
It is attached to the upper surface of 7 and can move linearly along two horizontal axes that are orthogonal to each other. The upper surface of the wafer fixing table 13 is a horizontal wafer fixing surface 18
The surface 18 is rotatable in both forward and reverse directions about the vertical axis. Wafer fixing surface 1
The semiconductor wafer 11 is fixed to the semiconductor wafer 8 by vacuum suction while being attached to the dicing tape 19.

Further, the dicing apparatus 10 of this embodiment.
In the lower part of the spindle head 15, a CCD camera 20 as an image pickup means for picking up an image of the surface of the semiconductor wafer 11 is provided. The CCD camera 20 can image the area adjacent to the blade 12. In addition, the CCD camera 20
Is connected to a computer 22 which is an image processing means via an A / D converter 21.

The analog information of the image picked up by the CCD camera 20 is digitized by the A / D converter 21 and input to the computer 22. The computer 22 can perform image processing on the input image information according to an appropriate algorithm to detect the position of the cutting line. The position information of the cutting line detected by the computer 22 is input to a controller (control means) 23 for controlling the rotation of the blade 12, the vertical movement of the spindle head 15 and the horizontal movement of the wafer fixing table 13, and the cutting line The semiconductor wafer 11 is cut.

Further, in this embodiment, a cleaning water removing device 26 for removing the cleaning water remaining in the imaging area is provided. This is to blow out the cleaning water by injecting a gas such as air or an inert gas. The gas injection nozzle 27 is located below the spindle head 15 and
It is located near the CD camera 20 and the wash water jet nozzle 25.

FIG. 2 shows a semiconductor wafer 1 to be cut.
1 is a plan view schematically showing the surface of the semiconductor wafer 1 of FIG.
A solid line drawn in a grid pattern in 1 is a scribe line S. The dicing method according to this embodiment will be described below with reference to FIG. In the following description, the direction parallel to the horizontal scribe line S shown in FIG. 2 will be referred to as the X-axis direction, and the direction parallel to the vertical scribe line S will be referred to as the Y-axis direction.

First, the semiconductor wafer 11 having a scribe line on its surface is sucked and fixed on the wafer fixing table 13 (step 100). Next, the wafer fixing table 13 is moved so that the peripheral area of the cutting line for first cutting, that is, the uppermost scribe line S in the X-axis direction in FIG. 2 is arranged below the CCD camera 20. Next, the wafer fixing table 13 is controlled via the controller 23, the wafer fixing table 13 is moved in the X-axis direction, and the imaging regions P _{11 to} P ₁₁ shown by dotted lines in FIG.
Image ₁₅ sequentially. The analog information of the image captured by the CCD camera 20 is digitized by the A / D converter 21, and then input to the computer 22 and stored in the memory.

Next, the information of the scribe line S is extracted by adding various conditions to all the input image information. As a condition for extracting the scribe line information, the width of the V groove and its allowable range are particularly important. For example, the maximum allowable value of the V groove width is 100 μm and the minimum allowable value is 50 μm.

The surface of the semiconductor wafer 11 is rotated along the scribe line S by rotating the V-groove forming blade 12-A.
The groove is moved in the axial direction and the Y-axis direction to form a V groove (step 101). FIG. 3 is a diagram showing the V groove width and its allowable range. The formed groove width is imaged by the CCD camera 20 while forming the V groove, input to the computer 22 and detected, and the allowable range is determined. If the V-groove width is out of the predetermined range, the controller 23 adjusts the gap between the wafer fixing table 13 and the blade 12-A to control it (step 102).

Next, the V-groove forming blade 12-A is replaced with the cutting blade 12 (step 103), and cutting is performed along the V-groove on the semiconductor wafer previously formed (step 104). The thickness of the cutting blade 12 is not more than the minimum allowable value of the V groove width, and a blade having a thickness of 20 to 40 μm is used depending on the thickness of the wafer. Since this method automatically detects and controls the V groove width, it can be applied even when the thickness of the semiconductor wafer, the dicing tape, or the flatness of the wafer fixing surface varies.

FIG. 5 is a process diagram showing another dicing method according to this embodiment. In this method, instead of step 102 in the method of FIG. 4, while forming the V-groove along one scribe line, C is formed around the adjacent V-groove.
The image is taken by the CD camera 20, the groove width is detected by the same means as described above, and the controller 23 adjusts and controls the interval between the wafer fixing table 13 and the blade 12-A based on the result (step 202). Other steps are the same as those in FIG. In this method, the position of the V groove measured as compared with that in FIG. 4 is far from the blade forming the V groove, so that it is possible to more clearly capture an image.

FIG. 6 is a process diagram showing another dicing method according to this embodiment. First, a V groove having a predetermined width is formed on the surface of the semiconductor wafer 11 suction-fixed on the wafer fixing table 13 by the same means as described above (step 301). Next, after stopping this process, the V groove is imaged by the CCD camera 20 or the like, and the V groove width is detected directly or by A / D conversion (step 30).
2). If the groove width at this time is within the allowable range, the V-groove forming blade 12-A is replaced with the cutting blade 12-B (step 304), and the wafer is cut along the V groove (step 306). If the V groove width is out of the allowable range, the wafer fixing table and the V groove forming blade 12-A
Is adjusted (step 305), and V-grooves are formed again on the surface of a new wafer. This method is suitable because the operation is simple when the thickness of the semiconductor wafer is uniform and the apparatus has reproducibility.

[0024]

As described above, the method for dicing a semiconductor wafer according to the present invention detects the V-groove width and adjusts the distance between the blade and the wafer surface so that the V-groove width falls within the allowable range. Since it is controlled, adjustment and control are easy, and it is easy to obtain an accurate groove width. Therefore, it is possible to cut a chip having a uniform edge. Further, since the semiconductor wafer dicing apparatus according to the present invention has a function of allowing the groove width to fall within the allowable range while forming the V groove, even when the thickness of the semiconductor wafer or the like varies. Can be applied.

[Brief description of drawings]

FIG. 1 is a schematic view showing a configuration of a semiconductor wafer dicing apparatus according to this embodiment.

FIG. 2 is a plan view showing a scribe line and an imaging region of a semiconductor wafer.

FIG. 3 is a diagram showing a V groove width and its allowable range.

FIG. 4 is a process diagram illustrating a semiconductor wafer dicing method according to this embodiment.

FIG. 5 is a process diagram illustrating a semiconductor wafer dicing method according to another embodiment.

FIG. 6 is a process diagram illustrating a semiconductor wafer dicing method according to another embodiment.

FIG. 7 is a diagram illustrating a conventional method for dicing a semiconductor wafer.

[Explanation of symbols]

 10: Dicing device 11: Semiconductor wafer 12: Dicing blade (cutting means) 13: Wafer fixing table (wafer fixing means) 15: Spindle head 18: Wafer fixing surface 19: Dicing tape 20: CCD camera (imaging means) 21: A / D converter 22: Computer (image processing means) 23: Controller (control means) 25: Wash water nozzle 26: Wash water removal device 27: Gas injection nozzle 28: Chip 30: Collet

Claims (8)

[Claims] 1. A V-shaped groove is formed on the surface of a semiconductor wafer, the V-groove width is detected, and the V-groove width is controlled so as to fall within a predetermined range, and then the semiconductor wafer is moved along the V-groove. A method for dicing a semiconductor wafer, which comprises cutting the wafer. 2. A V-groove width is detected by capturing an image of the periphery of an adjacent V-groove while capturing one V-groove, capturing image information of the image, and processing the image information. The method for dicing a semiconductor wafer according to claim 1, wherein 3. The V-groove width is detected by forming an image of the V-groove and simultaneously capturing the image information of the periphery of the V-groove and image-processing the image information. Item 1. A method for dicing a semiconductor wafer according to item 1. 4. A V-shaped groove is formed on the surface of a semiconductor wafer, the V-groove width is detected, and the V-groove width is adjusted so as to fall within a predetermined range. Thereafter, a semiconductor is formed along the V-groove. A method of dicing a semiconductor wafer, which comprises cutting the wafer. 5. The method for dicing a semiconductor wafer according to claim 1, wherein a V-shaped groove is formed on the surface of the semiconductor wafer by rotating a disk-shaped blade having a V-shaped circumferential cross section. 6. The method of dicing a semiconductor wafer according to claim 1, wherein the semiconductor wafer is cut by rotating a disk-shaped blade having a square circumferential cross section. 7. The method for dicing a semiconductor wafer according to claim 6, wherein the thickness of the blade is smaller than the minimum value of the V groove width. 8. A means for forming a V groove on the surface of a semiconductor wafer, a cutting means for cutting the semiconductor wafer, and a wafer fixing surface for fixing the semiconductor wafer, and the wafer fixing surface and the V groove forming means. Of the semiconductor wafer fixed on the wafer fixing surface and capturing image information of the semiconductor wafer fixed on the wafer fixing surface, and image information input from the image capturing means. Image processing means for performing image processing to detect the width of the V groove, and control means for inputting the V groove width detected by the image processing means and controlling the relative position between the semiconductor wafer and the V groove forming means. A dicing apparatus for a semiconductor wafer, comprising: forming a V groove, detecting the V groove width, controlling the V groove width, and cutting the semiconductor wafer. Wafer dicing equipment.