JP2021044481A - Processing device - Google Patents

Abstract

To provide a processing device that can properly obtain information on a workpiece.SOLUTION: A processing device includes: a chuck table with a holding surface for holding a workpiece; a processing unit that processes the workpiece held by the chuck table; an imaging unit that images the holding surface side of the chuck table and generates an image; and a control unit including a two-dimensional code extraction portion that extracts a two-dimensional code attached to the workpiece from a plurality of images generated by the imaging unit, and a two-dimensional code information storage portion that stores two-dimensional code information extracted by the control unit including code extraction portion. The two-dimensional code extraction portion extracts a two-dimensional code from one image obtained by joining the plurality of images generated by the imaging unit.SELECTED DRAWING: Figure 3

Description

The present invention relates to a processing apparatus used when processing a workpiece.

In electronic devices such as mobile phones and personal computers, a device chip including a device such as an electronic circuit is an indispensable component. In the device chip, for example, the surface of a wafer made of a semiconductor material such as silicon is divided into a plurality of regions by a planned division line (street), a device is formed in each region, and then the wafer is placed along the planned division line. Obtained by dividing.

When dividing a wafer into a plurality of device chips, for example, a cutting device equipped with an annular cutting blade in which abrasive grains such as diamond are hardened with a binder such as metal or resin is used. By rotating the cutting blade at high speed and cutting into the wafer along the planned division line, the wafer can be divided into a plurality of device chips.

By the way, when processing a plate-shaped workpiece such as a wafer with an automated processing apparatus such as a cutting apparatus, it is necessary to have the processing apparatus acquire information on the workpiece in advance. For such a purpose, a technique for reading a one-dimensional code (bar code) attached to a wafer with a processing apparatus has been proposed (see, for example, Patent Document 1). By using this technique, the operator does not have to manually register the workpiece information in the processing apparatus, so that human error is less likely to occur.

Japanese Unexamined Patent Publication No. 9-7977

In recent years, as the amount of information used in a processing apparatus has increased, it has become common to attach a two-dimensional code having a larger capacity than that of a one-dimensional code to a workpiece. However, this processing apparatus is configured to read a two-dimensional code using an imaging unit suitable for observing a narrow range of the workpiece, and cannot read a somewhat large two-dimensional code.

The present invention has been made in view of such problems, and an object of the present invention is to provide a processing apparatus capable of appropriately acquiring information on a workpiece.

According to one aspect of the present invention, an image is taken of a chuck table having a holding surface for holding a workpiece, a processing unit for processing the workpiece held by the chuck table, and the holding surface side of the chuck table. An imaging unit that generates an image, a two-dimensional code extraction unit that extracts a two-dimensional code associated with the workpiece from a plurality of images generated by the imaging unit, and the two-dimensional code extraction unit that extracts the two-dimensional code. A two-dimensional code information storage unit for storing two-dimensional code information and a control unit including the two-dimensional code information storage unit are provided, and the two-dimensional code extraction unit is one image obtained by joining a plurality of images generated by the image pickup unit. A processing device for extracting the two-dimensional code from the above is provided.

In one aspect of the present invention, the control unit is composed of a dispersion calculation unit that calculates the dispersion of pixel values from a plurality of pixel values representing the gradation of each pixel in the image generated by the imaging unit, and the imaging unit. A reference storage unit that stores the dispersion of pixel values that serves as a reference for determining whether or not the two-dimensional code appears in the generated image, and the dispersion of pixel values calculated by the dispersion calculation unit and the reference. The two-dimensional code extraction includes a determination unit that compares with the dispersion of pixel values stored in the storage unit and determines whether or not the two-dimensional code appears in the image generated by the imaging unit. It is preferable that the unit extracts the two-dimensional code from one image obtained by joining a plurality of images determined by the determination unit to show the two-dimensional code.

The processing apparatus according to one aspect of the present invention includes a two-dimensional code extraction unit that extracts a two-dimensional code attached to a workpiece from a plurality of images generated by an imaging unit, and a two-dimensional code extraction unit that extracts the two-dimensional code. It includes a two-dimensional code information storage unit that stores code information, and a control unit that includes the code information.

Then, the two-dimensional code extraction unit of the control unit extracts the two-dimensional code from one image obtained by joining a plurality of images generated by the imaging unit. Therefore, according to the processing apparatus according to one aspect of the present invention, it is possible to appropriately acquire information about the workpiece by reading a two-dimensional code having a size exceeding the range that can be imaged by the imaging unit.

FIG. 1 is a perspective view schematically showing a cutting device. FIG. 2 is a plan view schematically showing a workpiece or the like. FIG. 3 is a functional block diagram schematically showing a control unit and the like. FIG. 4 is a plan view schematically showing a region that is likely to contain a two-dimensional code. FIG. 5 is a diagram schematically showing a plurality of images determined to show a two-dimensional code. FIG. 6 is a diagram schematically showing an image generated by the image combining portion.

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing a cutting device (processing device) 2 according to the present embodiment, and FIG. 2 is a plan view schematically showing a workpiece 11 and the like. The X-axis direction (machining feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (height direction) used in the following description are perpendicular to each other.

The cutting device 2 of the present embodiment includes a frame (not shown) that supports each component. This frame is covered by a cover 4, as shown in FIG. A space for cutting the plate-shaped workpiece 11 is formed inside the frame and the cover 4, and the cutting unit (machining unit) 6 is housed in this space.

The workpiece 11 is typically a disk-shaped wafer formed by using a semiconductor such as silicon. As shown in FIG. 2, the surface 11a of the workpiece 11 is divided into a plurality of regions by, for example, grid-arranged division schedule lines (streets) 13, and each region is divided into ICs (Integrated Circuits). And other devices 15 are formed.

When the work piece 11 is cut by the cutting device 2, a tape (dicing tape) 17 having a diameter larger than that of the work piece 11 is attached to the back surface side of the work piece 11. Further, the annular frame 19 is adhered to the outer peripheral portion of the tape 17. That is, the workpiece 11 is carried into the cutting device 2 in a state of being supported by the frame 19 via the tape 17.

Further, in the present embodiment, a matrix-type two-dimensional code 21 in which data cells serving as a unit of information are arranged vertically and horizontally is attached to a portion of the tape 17 located between the workpiece 11 and the frame 19. That is, the workpiece 11 is accompanied by the two-dimensional code 21. The two-dimensional code 21 contains various information regarding the workpiece 11 such as cutting conditions and product types.

There are no restrictions on the material, shape, structure, size, etc. of the work piece 11. For example, a substrate formed of other semiconductors, ceramics, resins, metals, etc. can be used as the workpiece 11. Similarly, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the device. A device may not be formed on the workpiece 11.

The cutting unit 6 includes a spindle (not shown) having a rotation axis that is substantially parallel to the Y-axis direction. An annular cutting blade 8 formed by fixing abrasive grains such as diamond with a binder such as resin or metal is mounted on one end side of the spindle. A rotary drive source (not shown) such as a motor is connected to the other end side of the spindle.

A nozzle 10 capable of supplying a cutting fluid such as pure water to the workpiece 11 and the cutting blade 8 is arranged near the cutting blade 8. The cutting unit 6 is supported by a cutting unit moving mechanism (not shown), and is moved in the Y-axis direction and the Z-axis direction by the cutting unit moving mechanism.

A chuck table 12 capable of holding the workpiece 11 is arranged below the cutting unit 6. The chuck table 12 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis substantially parallel to the Z-axis direction. Further, the chuck table 12 is supported by a chuck table moving mechanism (not shown), and the chuck table moving mechanism moves the chuck table 12 in the X-axis direction.

A part of the upper surface of the chuck table 12 is made of, for example, a porous material, and becomes a holding surface 12a for holding the workpiece 11. The holding surface 12a is formed substantially parallel to the X-axis direction and the Y-axis direction, and is connected to a suction source (not shown) via a suction path (not shown) provided inside the chuck table 12. Has been done. Further, around the chuck table 12, four clamps 14 capable of fixing the annular frame 19 that supports the work piece 11 are provided.

An image pickup unit 16 including an image pickup element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor, and a lens for imaging is arranged on the side of the cutting unit 6. .. The image pickup unit 16 is configured to be able to generate an image by taking an image of the holding surface 12a side of the chuck table 12.

The cutting device 2 of the present embodiment can appropriately acquire information about the workpiece 11 even when a two-dimensional code 21 having a size exceeding the range that can be imaged by the imaging unit 16 is used. The image pickup unit 16 generates, for example, a grayscale image in which each pixel is represented by 8 bits, but may be configured to be able to generate a color image or a black-and-white image.

A cassette support 18 is provided on the outside of the frame and the cover 4. A cassette (not shown) capable of accommodating a plurality of workpieces 11 is placed on the upper surface of the cassette support base 18. The height (position in the Z-axis direction) of the cassette support 18 is controlled by an elevating mechanism (not shown) so that the work piece 11 can be carried out from the cassette and the work piece 11 can be carried into the cassette.

A touch panel 20 serving as a user interface is provided on the front surface 4a of the cover 4. An indicator light 22 is arranged on the upper surface 4b of the cover 4. The touch panel 20 and the indicator light 22 are connected to the control unit 24 together with the cutting unit 6, the cutting unit moving mechanism, the chuck table moving mechanism, the rotation drive source, the imaging unit 16, and the like.

The control unit 24 includes a cutting unit 6, a cutting unit moving mechanism, a chuck table moving mechanism, a rotary drive source, an imaging unit 16, a touch panel 20, an indicator light 22, and the like so that appropriate cutting of the workpiece 11 can be realized. Control the components. The control unit 24 is typically composed of a processing device such as a CPU (Central Processing Unit) and a computer including a storage device such as a flash memory. The function of the control unit 24 is realized by operating the processing device or the like according to the software stored in the storage device.

FIG. 3 is a functional block diagram schematically showing the control unit 24 and the like. The control unit 24 includes, for example, an imaging instruction unit 24a that instructs the operation of the imaging unit 16 and the like. The image pickup instruction unit 24a is configured to be able to access the start area storage unit 24b in which the information of the area for starting imaging (hereinafter referred to as the start area) is stored.

For example, when the work piece 11 or the like is carried into the chuck table 12, the image pickup instruction unit 24a of the control unit 24 takes an image of the two-dimensional code 21 attached to the work piece 11 in order to acquire information about the work piece 11. Let the unit 16 take an image. In this embodiment, a two-dimensional code 21 having a size exceeding the range that can be imaged by the image pickup unit 16 is used.

Therefore, the imaging instruction unit 24a of the control unit 24 relatively moves or rotates the chuck table 12 and the imaging unit 16 to sequentially image a plurality of regions likely to include the two-dimensional code 21 on the imaging unit 16. Let me. FIG. 4 is a plan view schematically showing a region that is likely to include the two-dimensional code 21.

Note that FIG. 4 shows the entire region that is likely to include the two-dimensional code 21. This region is determined in consideration of, for example, a positional deviation (error) expected when the two-dimensional code 21 is attached to the tape 17. Further, each of the plurality of regions divided by the vertical line and the horizontal line represents a region imaged at one time by the image pickup unit 16.

First, the image pickup instruction unit 24a reads out the information about the start area stored in the start area storage unit 24b, and causes the image pickup unit 16 to take an image of this start area. In the present embodiment, for example, the central region (D, 4) of FIG. 4 is set as the start region. Therefore, the image pickup unit 16 first takes an image of the area (D, 4) to generate an image. As shown in FIG. 3, the image pickup unit 16 is connected to the image storage unit 24c included in the control unit 24, and the image information generated by the image pickup unit 16 is stored in the image storage unit 24c.

When the image of the area (D, 4) is generated, the control unit 24 determines whether or not the two-dimensional code 21 is reflected in this image. As shown in FIG. 3, the control unit 24 includes a dispersion calculation unit 24d configured to be accessible to the image storage unit 24c. The dispersion calculation unit 24d reads out the image information stored in the image storage unit 24c, and calculates the dispersion of the pixel values from a plurality of pixel values representing the gradation of each pixel in the image.

In the present embodiment, since the grayscale image is generated by the image pickup unit 16, the pixel value of each pixel in the image takes a value of 0 to 255. The variance calculation unit 24d calculates the variance of the pixel values of the target image by using, for example, the following equation (1) and the pixel values of all the pixels in the image. In the equation (1), n represents the number of pixels in the target image, x _i represents the pixel value (0 to 255) of the i-th pixel, and “x bar” represents all the pixels in the image. Represents the arithmetic mean of the pixel values of pixels (n).

The variance of the pixel values calculated based on the above equation (1) becomes larger as the gradation of the pixels constituting the image varies. Specifically, for example, the dispersion of the pixel values when the workpiece 11 or the tape 17 is shown in the image is smaller than the dispersion of the pixel values when the two-dimensional code 21 is shown in the image. By using this dispersion of pixel values, it is possible to determine whether or not the two-dimensional code 21 appears in the image.

As shown in FIG. 3, the variance calculation unit 24d is connected to a determination unit 24e that can determine whether or not the two-dimensional code 21 is shown in the image. The variance of the pixel values calculated by the variance calculation unit 24d is sent to the determination unit 24e and used to determine whether or not the two-dimensional code 21 is reflected in the image.

Further, the determination unit 24e is configured to be able to access the reference storage unit 24f in which information regarding the dispersion (reference value) of the pixel value, which is the reference at the time of determination, is stored. The dispersion of the pixel values, which is the reference for the determination, is, for example, the lower limit of the dispersion of the pixel values when the two-dimensional code 21 is shown in the image, or the pixel values when the two-dimensional code 21 is shown in the image. This is the upper limit of the variance of.

The determination unit 24e compares the dispersion of the pixel values calculated by the dispersion calculation unit 24d with the dispersion of the pixel values stored in the reference storage unit 24f, and determines whether or not the two-dimensional code 21 appears in the image. judge. For example, the dispersion of the pixel values calculated by the dispersion calculation unit 24d is equal to or greater than the lower limit of the dispersion of the pixel values stored in the reference storage unit 24f, and the upper limit of the dispersion of the pixel values stored in the reference storage unit 24f. In the following cases, the determination unit 24e determines that the two-dimensional code 21 appears in the image.

Further, when the dispersion of the pixel values calculated by the dispersion calculation unit 24d is less than the lower limit of the dispersion of the pixel values stored in the reference storage unit 24f, or the dispersion of the pixel values stored in the reference storage unit 24f. If it is larger than the upper limit value, the determination unit 24e determines that the two-dimensional code 21 is not shown in the image. The result of the determination by the determination unit 24e is sent to the imaging region determination unit 24g that determines the next imaging region.

When it is determined that the two-dimensional code 21 is not shown in the image, the imaging region determining unit 24g next captures another region at an arbitrary distance from the region imaged immediately before (hereinafter, the next imaging). Area). For example, the imaging region determination unit 24g determines a region at an arbitrary distance from the end of the region (D, 4) as the next imaging region, with the range that the imaging unit 16 can image at one time as a unit of distance.

The distance used to determine the imaging region is not particularly limited, but it is desirable to use the largest distance among those that can appropriately find the two-dimensional code 21. As a result, the time required to find the two-dimensional code 21 can be minimized. In this embodiment, one unit of distance is used as this distance.

That is, in the present embodiment, the range (F, 4) at a distance of 1 unit from the end of the region (D, 4) is determined as the next imaging region, with the range that can be imaged by the imaging unit 16 as the unit of distance. .. When the next imaging region is determined by the imaging region determining unit 24g, this imaging region is imaged in the same procedure, and it is determined whether or not the two-dimensional code 21 is included in the generated image.

When it is determined that the two-dimensional code 21 does not appear in the image generated by imaging the region (F, 4), the imaging region determination unit 24g is one unit from the end of the region (F, 4). The region (F, 6) at a distance is determined as the next imaging region. Such a procedure is continued until an image determined to contain the two-dimensional code 21 is obtained.

Specifically, for example, region (F, 6), region (D, 6), region (B, 6), region (B, 4), region (B, 2), region (D, 2), region. Imaging and determination are repeated in the order of (F, 2). As described above, in the present embodiment, the next imaging region is determined along the spiral locus from the central start region to the outside. Therefore, the two-dimensional code 21 can be efficiently found.

When it is determined that the two-dimensional code 21 appears in the image, the imaging region determination unit 24g determines the region adjacent to the region imaged immediately before as the next imaging region. As shown in FIG. 4, when the region (D, 4) is imaged, a part of the two-dimensional code 21 appears in the generated image. Therefore, the imaging region determination unit 24g determines the region (E, 4) adjacent to the region (D, 4) as the next imaging region.

When the next imaging region is determined by the imaging region determining unit 24g, this imaging region is imaged in the same procedure. Then, the imaging region determination unit 24g further determines the adjacent region as the next imaging region. Such a procedure is continued until the entire two-dimensional code 21 is imaged, for example, based on information such as the size of the two-dimensional code 21. Specifically, for example, region (E, 5), region (D, 5), region (C, 5), region (C, 4), region (C, 3), region (D, 3), region. Imaging is repeated in the order of (E, 3).

After imaging each region, it is determined whether or not the two-dimensional code 21 is reflected in the generated image. Then, when it is determined that the two-dimensional code 21 does not appear in the image obtained by imaging the target imaging region, it exists in the direction including this imaging region when viewed from the previous imaging region. It is desirable to exclude this region from the next imaging region.

For example, when it is determined that the two-dimensional code 21 does not appear in the image obtained by imaging the region (E, 4), this region (E, 4) is viewed from the previous region (D, 4). It is preferable to exclude the region (E, 3) and the region (E, 5) existing in the direction including, 4) from the next imaging region. In this way, by determining the next imaging region using the result of determining whether or not the two-dimensional code 21 is captured in the image, the entire two-dimensional code 21 can be imaged in a shorter time.

FIG. 5 is a diagram schematically showing a plurality of images determined to show the two-dimensional code 21. The image 23a is generated by imaging the region (C, 3), the image 23b is generated by imaging the region (D, 3), and the image 23c is the imaging of the region (E, 3). Generated by.

Further, the image 23d is generated by imaging the region (C, 4), the image 23e is generated by imaging the region (D, 4), and the image 23f images the region (E, 4). It is generated by doing. Then, the image 23g is generated by imaging the region (C, 5), the image 23h is generated by imaging the region (D, 5), and the image 23i images the region (E, 5). It is generated by doing.

As shown in FIG. 3, the control unit 24 has an image combining unit 24h configured to be accessible to an image storage unit 24c in which a plurality of images determined to have the two-dimensional code 21 are stored. Including. The image combining unit 24h connects a plurality of images (that is, image 23a, image 23b, image 23c, image 23d, image 23e, image 23f, image 23g, image 23h, image 23i) to generate one image. To do.

FIG. 6 is a diagram schematically showing an image 25 generated by the image coupling unit 24h. In FIG. 6, the portion corresponding to the boundary of the plurality of images before the combination is shown by a broken line. For example, the two pre-combined images captured in two adjacent regions are formed to have slightly overlapping portions and are coupled to each other so as to overlap the overlapping portions.

As shown in FIG. 3, a two-dimensional code extraction unit 24i configured to be able to extract the two-dimensional code 21 from the image 25 in which the two-dimensional code 21 is captured is connected to the image coupling unit 24h. The image 25 generated by the image combining unit 24h is sent from the image combining unit 24h to the two-dimensional code extraction unit 24i.

As shown in FIG. 3, the two-dimensional code extraction unit 24i is configured to be able to access the two-dimensional code information storage unit 24j that stores the information contained in the extracted two-dimensional code 21. The information of the two-dimensional code 21 extracted by the two-dimensional code extraction unit 24i is stored in the two-dimensional code information storage unit 24j and is used, for example, when cutting the workpiece 11.

As described above, the cutting device (processing device) 2 of the present embodiment has a plurality of images (image 23a, image 23b, image 23c, image 23d, image 23e, image 23f, image 23g) generated by the imaging unit 16. The two-dimensional code extracting unit 24i that extracts the two-dimensional code 21 attached to the workpiece 11 from the image 23h and the image 23i) and the two-dimensional code that stores the information of the two-dimensional code 21 extracted by the two-dimensional code extraction unit 24i. It includes an information storage unit 24j and a control unit 24 including the information storage unit 24j.

Then, the two-dimensional code extraction unit 24i of the control unit 24 extracts the two-dimensional code 21 from one image 25 in which a plurality of images generated by the imaging unit 16 are joined. Therefore, according to the cutting device 2 according to the present embodiment, the two-dimensional code 21 having a size exceeding the image pickup range of the image pickup unit 16 can be read to appropriately acquire information about the workpiece 11.

The present invention is not limited to the description of the above-described embodiment, and can be implemented with various modifications. For example, in the above-described embodiment, the cutting device 2 used for cutting the plate-shaped workpiece 11 has been described as an example, but the machining device of the present invention processes the workpiece 11 with a laser beam. A laser processing device or the like may be used.

Further, in the above-described embodiment, the two-dimensional code 21 attached to the tape 17 has been described as an example, but the two-dimensional code 21 may be attached to at least the workpiece 11. For example, the processing apparatus of the present invention is also useful when a two-dimensional code 21 is attached to a part of the surface 11a of the workpiece 11. In this case, it is not always necessary to use the tape 17, the frame 19, or the like.

Further, in the above-described embodiment, the so-called sample variance is adopted as the dispersion of the pixel values, but other indexes representing the variations in the pixel values can also be adopted. For example, unbiased dispersion may be adopted as the dispersion of pixel values.

In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

2: Cutting equipment (processing equipment)
4: Cover 4a: Front surface 4b: Top surface 6: Cutting unit (machining unit)
8: Cutting blade 10: Nozzle 12: Chuck table 12a: Holding surface 14: Clamp 16: Imaging unit 18: Cassette support 20: Touch panel 22: Indicator light 24: Control unit 24a: Imaging indicator 24b: Start area storage unit 24c : Image storage unit 24d: Dispersion calculation unit 24e: Judgment unit 24f: Reference storage unit 24g: Imaging area determination unit 24h: Image coupling unit 24i: Two-dimensional code extraction unit 24j: Two-dimensional code information storage unit 11: Workpiece 11a: Surface 13: Scheduled division line (street)
15: Device 17: Tape (dicing tape)
19: Frame 21: Two-dimensional code 23a: Image 23b: Image 23c: Image 23d: Image 23e: Image 23f: Image 23g: Image 23h: Image 23i: Image 25: Image

Claims (2)

A chuck table with a holding surface for holding the workpiece,
A processing unit for processing the workpiece held by the chuck table, and
An imaging unit that images the holding surface side of the chuck table to generate an image, and
A two-dimensional code extraction unit that extracts a two-dimensional code associated with the workpiece from a plurality of images generated by the imaging unit, and a two-dimensional code information extracted by the two-dimensional code extraction unit are stored. A control unit including a two-dimensional code information storage unit is provided.
The two-dimensional code extraction unit is a processing device characterized by extracting the two-dimensional code from one image obtained by joining a plurality of images generated by the imaging unit. The control unit includes a dispersion calculation unit that calculates the dispersion of pixel values from a plurality of pixel values representing the gradation of each pixel in the image generated by the image pickup unit, and the image generated by the image pickup unit. A reference storage unit that stores the dispersion of pixel values that serves as a reference when determining whether or not a dimension code is captured, the dispersion of pixel values calculated by the dispersion calculation unit, and the pixels stored in the reference storage unit. Further including a determination unit for determining whether or not the two-dimensional code is reflected in the image generated by the imaging unit by comparing with the dispersion of values.
The two-dimensional code extraction unit is characterized in that the two-dimensional code extraction unit extracts the two-dimensional code from one image obtained by joining a plurality of images determined by the determination unit to show the two-dimensional code. The processing equipment described in.

Images