JP2009021375A - Chipping detecting method and chipping detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically and efficiently detect chipping which possibly occurs when a wafer is cut with a cutting blade along a laser grooving line while discriminating it from an affected portion. <P>SOLUTION: A division scheduled line after dicing is imaged while the quantity of light is set such that a working groove portion is white and its peripheral laser grooving portion is black with considering that a chipping portion due to cutting by the cutting blade is continuously caused at the edge position of a working groove area different from the affected portion (S2), the edge position of a laser grooving area and the edge position of a working groove area are extracted from the picked-up image (S3), and a histogram associated with the luminance distribution of image data of respective pixels in the laser grooving area within a predetermined range is generated (S4), and a first peak area which is brightest is extracted on the basis of the luminance distribution of the histogram (S6 to S7), and a part continuous to the edge position of the working groove area in the first peak area is recognized as a chipping area (S9 to S10). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a chipping detection method in a dicing apparatus and a chipping detection apparatus provided in the dicing apparatus.

  In order to increase the processing capability of circuits such as IC and LSI, semiconductor wafers in a form in which a low dielectric constant insulator film (Low-K film) is laminated on the surface of a semiconductor substrate such as Si have been put into practical use. A semiconductor wafer in which a metal pattern referred to as a test element group (Teg) is provided on a division line of a semiconductor wafer so that the circuit is checked before the semiconductor wafer is divided into individual semiconductor chips has been put into practical use.

  When such a wafer is cut along a line to be divided by a cutting blade, the Low-K film is peeled off, and this peeling reaches the circuit to cause fatal damage to the semiconductor chip. There is a problem that occurs. Therefore, a dividing method in which a Low-K film or a metal pattern is removed by irradiating a laser beam along a planned dividing line of a semiconductor wafer, and a cutting blade is positioned in the removed grooving region and cutting is attempted ( For example, see Patent Documents 1 and 2).

  For normal dicing, there is also a technology that detects the processed groove (kerf) after dicing, automatically measures the chipping size by image processing, and performs dicing while constantly checking the processing quality (for example, patents) Reference 3).

JP-A-2005-64231 JP 2003-320466 A Japanese Patent No. 3646781

  In the dividing methods disclosed in Patent Documents 1 and 2, etc., after forming several laser processing grooves, the cutting grooves are cut with a cutting blade, so that chipping by the cutting blade occurs in the laser processing grooves. Since it is within the range of the groove, the circuit can be processed without problems. However, if the cutting blade wears out, breaks, etc. and the sharpness decreases, the chipping that occurs during cutting increases and may reach the circuit side beyond the laser processing groove range. Need to be monitored.

  Here, since the Si, Low-K film, Teg, etc. are melted and re-solidified in the laser processing groove after the laser irradiation and become non-uniform, the chipping is recognized when the chipping in the processing groove is recognized by an image. It is difficult to distinguish from the modified material in the processing groove. Therefore, a normal dicing check method as disclosed in Patent Document 3 cannot be applied, and it is difficult to automatically detect chipping. For this reason, the processed semiconductor wafer is extracted and the chipping detection is performed visually by an operator or the like, which is time consuming and inefficient.

  The present invention has been made in view of the above, and is capable of automatically and efficiently detecting chipping that may occur when a wafer is cut with a cutting blade along a laser grooving line from an altered portion. An object is to provide a detection method and a chipping detection device.

  In order to solve the above-described problems and achieve the object, a chipping detection method according to the present invention cuts a wafer that has been laser-grooved along a division line that divides a plurality of chips along the laser grooving line. A chipping detection method in a dicing apparatus that divides by a blade, wherein the light amount is set so that a kerf portion formed by the cutting blade is white and a surrounding laser grooving portion is black, and the division after dicing by the cutting blade is performed An imaging process for imaging a planned line by an imaging means, an edge extraction process for extracting an edge position of a laser grooving area and an edge position of a kerf area by edge recognition processing on an image captured by the imaging means, and an edge position extraction Within the laser grooving region within a predetermined range A histogram creating step for creating a histogram relating to the luminance distribution of the image data of each pixel; and a peak region extracting step for extracting the brightest first peak region from the laser grooving region in the predetermined range based on the luminance distribution in the created histogram. And a chipping region recognition step of recognizing a portion continuing to the edge position of the kerf region in the extracted first peak region as a chipping region.

  The chipping detection method according to the present invention includes the error determination step of determining a chipping error when the size of the chipping region recognized in the chipping region recognition step exceeds a predetermined value in the above invention, and the error determination And a notification step of notifying that when it is determined that a chipping error has occurred in the step.

  Further, the chipping detection method according to the present invention is the above-described invention, wherein the peak value of the luminance distribution in the histogram created in the histogram creating step is one, or the kerf region in the extracted first peak region. When there is no continuous portion at the edge position, a determination step of determining that there is no chipping is provided.

  The chipping detection apparatus according to the present invention is a chipping detection apparatus provided in a dicing apparatus that divides a wafer that has been laser-grooved along a division line that divides a plurality of chips with a cutting blade along the laser grooving line. An imaging means for imaging the division-scheduled line after dicing by the cutting blade by setting an amount of light so that a kerf portion formed by the cutting blade is white and a surrounding laser grooving portion is black, and the imaging Edge extraction means for extracting the edge position of the laser grooving area and the edge position of the kerf area by edge recognition processing on the image captured by the means, and for each pixel in the laser grooving area of the predetermined range from which the edge position is extracted Histogram of brightness distribution of image data Histogram creation means for creating, peak area extraction means for extracting the brightest first peak area from the laser grooving area in the predetermined range based on the luminance distribution in the created histogram, and in the extracted first peak area Chipping area recognition means for recognizing a portion continuing to the edge position of the kerf area as a chipping area.

  Further, the chipping detection apparatus according to the present invention is the error determination means for determining a chipping error when the size of the chipping area recognized by the chipping area recognition means exceeds a predetermined value. And a notifying means for notifying that when the means determines that a chipping error has occurred.

  The chipping detection apparatus according to the present invention is the above-described invention, wherein the peak value of the luminance distribution in the histogram created by the histogram creating means is one, or the kerf region in the extracted first peak region. When there is no continuous portion at the edge position, a determination means for determining that there is no chipping is provided.

  The chipping detection method and the chipping detection apparatus according to the present invention set the amount of light so that the laser grooving portion becomes black and pick up the divisional line after dicing and capture the altered portion and the chipping portion in the laser grooving with the highest luminance. The point that can be recognized as a bright part, and the chipping part resulting from cutting of the cutting blade is generated in the laser grooving area continuously at the edge position of the kerf area unlike the altered part that is scattered in the laser grooving. Focus on, and set the amount of light so that the kerf part is white and the surrounding laser grooving part is black, capture the planned division line after dicing, and the edge position of the laser grooving area and the edge position of the kerf area from the captured image And a predetermined range of labels from which the edge positions are extracted. A histogram relating to the luminance distribution of the image data of each pixel in the grooving region is created, the brightest first peak region is extracted from the laser grooving region in a predetermined range based on the luminance distribution in the created histogram, and the extracted first peak By distinguishing the portion that continues to the edge position of the kerf region in the region as the chipping region, the chipping that may occur when cutting the wafer with the cutting blade along the laser grooving line is distinguished from the altered portion. Thus, it is possible to automatically and efficiently detect the machining quality. Therefore, there is an effect that machining quality control can be performed automatically and periodically.

  Hereinafter, a chipping detection method and a chipping detection apparatus which are the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view showing an example of a dicing apparatus provided with a chipping detection apparatus according to an embodiment of the present invention. The dicing apparatus 1 is a cutting apparatus that divides a wafer 10 that has been laser-grooved by a laser processing machine (not shown) along a planned division line that divides a plurality of chips, by cutting with a cutting blade along the laser grooving line. . As shown in FIG. 1, the dicing apparatus 1 includes a chuck table 2 that holds a wafer 10, a cutting means 3 that performs a cutting process on the wafer 10 held on the chuck table 2, and a chipping detection device. 20.

  Here, the cutting means 3 is of a dual structure step cut type in which two cutting blades are arranged opposite to each other in the Y-axis direction and can perform a cutting operation in parallel, and has been laser processed and held on the chuck table 2. The first cutting blade 4 (see FIG. 4B) half-cuts the wafer 10, and the second cutting blade 5 is thinner than the first cutting blade 4 (see FIG. 4D). ) Performs a full cut of a half-cut portion. The cutting means 3 includes a spindle 6 on which a first cutting blade 4 is detachably mounted, and a cylindrical housing 7 including a drive source (not shown) that rotatably supports and rotates the spindle 6. A spindle (not shown) on which the second cutting blade 5 is detachably mounted, and a cylindrical housing 8 including a drive source (not shown) that rotatably supports and drives the spindle.

  Although the details of the dicing apparatus 1 are not particularly shown, a machining feed means for machining the chuck table 2 in the X-axis direction relative to the cutting means 3 and a cutting means 3 for cutting the chuck table 2 to the cutting means 3. Indexing feeding means for indexing and feeding relative to the Y-axis direction, and cutting feed means for cutting and feeding the cutting means 3 relative to the wafer 10 held by the chuck table 2 in the Z-axis direction.

  The chipping detection device 20 is for detecting a chipping state after half-cutting by the first cutting blade 4 with respect to the laser-processed wafer 10, and includes an imaging unit 21, a notification unit 22, a control unit 30, and the like. Is provided. The image pickup means 21 has, for example, an electron microscope structure provided on the side of the housing 7 and mounted with a CCD camera or the like for picking up an image of the surface of the wafer 10 held on the chuck table 2. This is for imaging the planned division line after cutting by one cutting blade 4. This imaging means 21 is also used for alignment for positioning the cutting blade with respect to the line to be cut. Further, the notification means 22 uses a display panel that displays various types of information. As will be described later, when it is determined that a chipping error has occurred, the notification means 22 displays that the chipping error has occurred and notifies the user. . The control unit 30 will be described later.

  Here, the configuration of the wafer 10 used in the present embodiment, and laser processing and step cutting for the wafer 10 will be described with reference to FIGS. 2 is a perspective view showing the appearance of the wafer 10, FIG. 3 is an enlarged cross-sectional view of a part thereof, and FIGS. 4A to 4E are cross-sectional views showing the division processing steps in the order of steps. FIG.

  A wafer 10 shown in FIG. 2 has a plurality of division lines 12 formed in a lattice pattern on a surface 11 a of a substrate 11 made of Si wafer, and chips 13 are formed in a plurality of areas partitioned by the plurality of division lines 12. Is formed. Here, as shown in FIG. 3, a low dielectric constant insulating film (Low-K film) 14 is laminated on the surface 11 a of the substrate 11, and the chip 13 is formed on the surface of the Low-K film 14. A circuit is formed. As shown in FIG. 2, the back surface of the wafer 10 formed in this manner is attached to the protective tape 16 attached to the annular frame 15 so that the wafer 10 is not separated when divided into individual chips 13. ing.

  By irradiating such a wafer 10 with a laser beam along a planned division line 12 in a laser processing machine (not shown), the layer is deeper than the layer of the Low-K film 14 as shown in FIG. A process for forming two laser grooving (laser machining grooves) 12a is performed. As a result, the Low-K film 14 is divided by the two laser grooving 12a. Such laser grooving 12 a is performed on all the division lines 12 formed on the wafer 10.

  Such a laser-processed wafer 10 is carried into the dicing apparatus 1 shown in FIG. 1 and is subject to a step cut process. First, the laser-processed wafer 10 is held on the chuck table 2, and the first cutting blade 4 having a predetermined thickness is positioned between the outer sides of the two laser grooving 12a as shown in FIG. 4B. Then, half cutting is performed by the first cutting blade 4 along the laser grooving line. The half-cut depth by the first cutting blade 4 is set to a depth that is deeper than the depth of the two laser grooving 12 a and stays in the middle of the substrate 11. As a result, as shown in FIG. 4C, the Low-K film 14 'remaining between the two laser grooving portions 12a is cut by the first cutting blade 4, and the outer side of the two laser grooving portions 12a. A kerf (cutting groove) 16a is formed between them. The formation of the kerf 16a by half-cutting using the first cutting blade 4 is performed for all the division planned lines 12 of the wafer 10.

  In parallel with the half-cut operation along the laser grooving line by the first cutting blade 4 as described above, as shown in FIG. 4 (d), the half-cut thickness of the kerf 16a that has already been half-cut is about half the thickness. The second cutting blade 5 is positioned, and the wafer 10 is fully cut to a depth that reaches the protective tape 15 on the back surface. As a result, as shown in FIG. 4E, a kerf 16b reaching the back surface is formed on the bottom surface of the kerf 16a. The wafer 10 is divided into individual chips 13 by forming the kerf 16b by full cutting using the second cutting blade 5 on all the division lines 12 of the wafer 10.

  Here, the chipping to be detected in the present embodiment is the wear and breakage of the first cutting blade 4 during the cutting with the first cutting blade 4 as shown in FIG. It may occur in the laser grooving 12a due to the above. If the degree of such chipping increases, the chip may reach the chip 13 side beyond the range of the laser grooving 12a. In this embodiment, a method for automatically detecting such chipping is provided. Is.

  A chipping detection apparatus 20 according to the present embodiment will be described with reference to FIG. FIG. 5 is a functional block diagram illustrating a configuration example of the control unit 30 in the chipping detection apparatus 20 according to the present embodiment. The control unit 30 has a microcomputer configuration including a storage unit 31, and includes an edge extraction unit 32, a histogram creation unit 33, a peak region extraction unit 34, a chipping region recognition unit 35, an error determination unit 36, and a determination unit 37. Function execution means is provided.

  The image pickup means 21 picks up an image of the parting line 12 after dicing by the first cutting blade 4 at a predetermined sampling timing under the control of the control unit 30. At this time, the first cutting blade 4 The amount of light is set so that the kerf 16a portion formed by the above is white and the surrounding laser grooving 12a portion is black. The storage unit 31 stores image data for each pixel imaged by the imaging unit 21 together with coordinate data of each pixel, as well as various data.

  Further, the edge extraction means 32 extracts the edge position of the laser grooving area and the edge position of the kerf area by edge recognition processing on the image picked up by the image pickup means 21 using image processing software as a known edge recognition algorithm. Perform the process. The histogram creation means 33 performs a process for creating a histogram relating to the luminance distribution of the image data of each pixel in the laser grooving region within a predetermined range from which the edge position is extracted. The peak area extraction unit 34 performs a process of extracting the brightest first peak area from a predetermined range of laser grooving areas based on the luminance distribution in the created histogram. The chipping area recognizing means 35 performs a process of determining that there is chipping by recognizing a portion continuing to the edge position of the kerf area in the extracted first peak area as a chipping area.

  Further, the error determination means 36 determines a chipping error when the size of the chipping area recognized by the chipping area recognition means 35 exceeds a predetermined value set in advance, and performs a process of notifying the fact through the notification means 22. Do. On the other hand, the determination unit 37 has a portion where the peak value of the luminance distribution in the histogram created by the histogram creation unit 33 is one, or a portion that continues to the edge position of the kerf region in the extracted first peak region. If not, processing for determining that there is no chipping is performed.

  Hereinafter, a chipping detection method using such a chipping detection apparatus 20 will be described with reference to a schematic flowchart shown in FIG. 6 and explanatory diagrams shown in FIGS. FIG. 6 is a schematic flowchart showing a processing control example of the chipping detection method. First, the control unit 30 monitors whether or not a predetermined sampling timing for performing a chipping check has been reached with respect to the division-scheduled line 12 after half-cutting by the first cutting blade 4 (step S1). ). If it is a sampling timing (step S1; Yes), the control part 30 will position the imaging means 21 in the division planned line 12 of the predetermined position after a half cut, and will image the division planned line 12 part (step S2: imaging process). . At this time, the light amount of the imaging unit 21 is set so that the kerf 16a portion formed by the first cutting blade 4 is relatively white (bright) and the surrounding laser grooving 12a portion is relatively black (dark). Take an image. FIG. 7 is an explanatory diagram showing the result of imaging the division line 12 at the sampling location by the imaging means 21. Image data for each pixel imaged by the imaging means 21 is stored in the storage unit 31 together with coordinate information of the XY coordinate system of each pixel.

  Subsequently, the edge extraction unit 33 of the control unit 30 performs a known edge recognition process on the image data of the scheduled division line 12 captured by the imaging unit 21 and stored in the storage unit 31. As shown in FIG. 8, the edge position E1 of the laser grooving region Eg composed of the laser grooving 12a portion and the edge position E2 of the kerf region Ek composed of the kerf 16a portion are extracted (step S3: edge extraction step). The extracted position information (straight line information) of the edge positions E1 and E2 is stored in the storage unit 31. In FIG. 8, the two-dot chain line indicates the planned division line 12 for reference. Further, in this process, the laser grooving region Eg in which the position in the Y-axis direction is divided by the edge positions E1 and E2 is divided by a preset coordinate position in the X-axis direction. The laser grooving area Eg is determined. A portion shown in an enlarged manner in FIG. 8 is the determined laser grooving region Eg within a predetermined range. Here, the image of the laser grooving region Eg within a predetermined range determined in FIG. 8 shows a state in which the whole is blackish but includes a whitish portion due to the chipping portion 17 and the altered portion 18 of the Si substrate.

  Then, the histogram creation means 34 of the control unit 30 creates a histogram relating to the luminance distribution of the image data (for example, 8 bits = 256 values) of each pixel in the laser grooving region Eg within a predetermined range (step S4: histogram creation step). ). FIG. 9 is an explanatory diagram showing an example of a histogram relating to the luminance distribution created based on the image data of each pixel in the laser grooving region Eg in such a predetermined range. Basically, since the image is taken by the imaging means 21 so that the laser grooving 12a portion becomes blackish, the image data is concentrated on the lower luminance side and has a large peak area, but chipping is also performed in the laser grooving area Eg. Since the portion 17 and the altered portion 18 are picked up as the brightest and brightest image data, the luminance distribution characteristics having a peak region as well as the higher luminance are exhibited. That is, when a chipping portion or the like is included, the luminance distribution in the histogram has a plurality of peak areas. For such a histogram, a smoothing process using a moving average or the like is performed in order to reduce an error on the image data (step S5). FIG. 10 shows an example of a histogram relating to the luminance distribution after the smoothing process.

  Next, the peak area extraction means 35 of the control unit 30 determines whether or not there are a plurality of peak areas by performing processing for dividing the created histogram relating to the luminance distribution into modes (step S6). In addition, as a method to divide into histogram modes, the method shown in the paper “Chang JH, Fan KC, Chang YL, Multi-Model gray-level histogram modeling and decomposition. Image and Vision Computing 20 (2002) 203-216” etc. Can be used. And when it has a some peak area (step S6; Yes), with respect to the image data of each pixel in the laser grooving area | region Eg of a predetermined range, it is the pole with respect to the peak area of the brightest side in the histogram regarding luminance distribution. The value is applied as the first threshold Th1, and the brightest first peak region in the laser grooving region Eg within a predetermined range is extracted by picking up and developing pixels brighter than the first threshold Th1 at each coordinate position. (Step S7: Peak region extraction step). Also in this case, in order to reduce the error on the image data, a smoothing process using a moving average or the like is performed (step S8). The region shown in black in FIG. 11 shows an example of the brightest first peak region extracted in the laser grooving region Eg within the predetermined range by the processing in steps S7 and S8.

  In this state, the mixed chipping portion 17 and the altered portion 18 cannot be distinguished. However, the chipping portion 17 generated due to the cutting of the first cutting blade 4 is different from the altered portion 18 generated by being scattered in the laser grooving region Eg, and continues to the edge position E2 of the kerf region Ek ( It has a characteristic that it occurs toward the laser grooving region Eg (starting from the edge position E2). Therefore, the chipping area recognition means 35 of the control unit 30 checks the continuity of the coordinate position of the first peak area extracted in the laser grooving area Eg within a predetermined range, thereby continuing to the edge position E2 of the kerf area Ek. It is determined whether or not there is a region to be processed (step S9). If there is a continuous region (step S9; Yes), the region is recognized as a chipping region, and a chipping portion is included in the laser grooving region Eg within a predetermined range. 17 is determined (step S10: chipping region recognition step). As a result, the presence of the chipping portion 17 is recognized separately from the altered portion 18.

  Here, even when the chipping portion 17 exists, the size thereof is various. Therefore, the error determination means 36 of the control unit 30 causes the size in the Y-axis direction from the edge position E2 of the chipping portion 17 recognized as the chipping region to exceed a predetermined value Th indicating a preset allowable value. It is determined from the coordinate data whether or not (step S11). If the size of the chipping portion 17 is large enough to exceed the predetermined value Th (step S11; Yes), the dicing operation in the dicing apparatus 1 is stopped and a warning that a chipping error has occurred through the notification means 22 is issued. Display is performed (step S12: notification step), and the user is prompted to deal with blade replacement or the like. If the chipping portion 17 is not large enough to exceed the predetermined value Th, the dicing operation in the dicing apparatus 1 is continued.

  On the other hand, if it is determined in step S6 that there is no plurality of peak regions and the peak value of the luminance distribution is one (step S6; No), there is no bright luminance distribution portion due to the chipping portion 17 or the altered portion 18. The determination means 37 of the control unit 30 performs chipping because it corresponds to a state in which the image data is concentrated on the lower brightness as a result of imaging with the imaging means 21 so that the laser grooving 12a portion becomes dark. It is determined that there is no item (step S13: determination step). Further, in the determination in step S9, the case where the first peak region continuous to the edge position E2 of the kerf region Ek does not exist (step S9; No) corresponds to the state in which only the altered portion 18 exists, so that the control is performed. The determination unit 37 of the unit 30 determines that there is no chipping (step S13: determination step).

  As described above, according to the present embodiment, when the amount of light is set so that the laser grooving 12a portion becomes black and the divided line 12 after dicing is imaged, the altered portion and the chipping portion in the laser grooving 12a are set to have brightness. The point that can be recognized as the brightest part, and the chipping part 17 resulting from the cutting of the first cutting blade 4 is continuous with the edge position E2 of the kerf region Eg, unlike the altered part 18 that is scattered in the laser grooving. Then, paying attention to the point generated in the laser grooving region Eg, the amount of light is set so that the kerf 16a portion is white and the surrounding laser grooving 12a portion is black, and the divided division line 12 after dicing is imaged. From the image, the edge position E1 of the laser grooving area Eg and the edge position E of the kerf area Ek And a histogram relating to the luminance distribution of the image data of each pixel in the laser grooving region Eg in the predetermined range from which the edge position E1 is extracted, and the laser grooving region in the predetermined range based on the luminance distribution in the generated histogram The brightest first peak region is extracted from Eg, and the portion that continues to the edge position E1 of the kerf region Ek in the extracted first peak region is recognized as the chipping region 18, so that the laser grooving line The chipping portion 17 that can be generated when the wafer 10 is cut by the first cutting blade 4 along the line can be distinguished from the altered portion 18 automatically and efficiently, so that the processing quality control is automatically and periodically performed. Can be done.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the present embodiment, the number of laser grooving 12a formed by laser processing of a laser processing machine is two, but may be a plurality of three or more. Further, the formed plurality of laser grooving may be formed so as to be continuous in the width direction of the planned division line 12.

  In the present embodiment, the laser dicing laser processing machine has been described as an example provided separately from the dicing apparatus 1, but a dicing apparatus that is integrally provided with a laser processing machine may be used. Furthermore, although the dicing apparatus 1 of the present embodiment has been described with an example of performing step cutting with a dual type configuration, dual cutting (simultaneous full cutting with two cutting blades) or only one cutting blade is used. The same applies to a type that performs single cut.

  Further, in this embodiment, when a chipping error is determined, an error is displayed by the notification means 22 by the display panel. However, the notification means may be an error notification by voice output or the like. .

  In the present embodiment, the example in which the wafer 10 having the Low-K film 14 is applied has been described. However, the present invention can be similarly applied to a wafer having a Teg pattern.

  In addition, the functions of the units 32 to 37 included in the control unit 30 according to the present embodiment may be realized by a chipping detection program that can be executed by a microcomputer included in the control unit 30 as each procedure.

It is an external appearance perspective view which shows an example of a dicing apparatus provided with the chipping detection apparatus of embodiment of this invention. It is a perspective view which shows the external appearance of a wafer. 2 is an enlarged cross-sectional view showing a part thereof. It is sectional drawing which shows a division | segmentation process process to process order. It is a functional block diagram which shows the structural example of the control part in the chipping detection apparatus of this Embodiment. It is a schematic flowchart which shows the process control example of a chipping detection method. It is explanatory drawing which shows the result of having imaged the division | segmentation planned line of a predetermined position with an imaging means. It is explanatory drawing which shows the division | segmentation planned line vicinity after an edge extraction process. It is explanatory drawing which shows the example of the histogram regarding the luminance distribution produced based on the image data of each pixel in the laser grooving area | region of a predetermined range. It is explanatory drawing which shows the example of the histogram regarding the luminance distribution after a smoothing process. It is a characteristic view which shows the example of the brightest 1st peak area | region extracted within the laser grooving area | region within a predetermined range.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chipping detection apparatus 3 Cutting means 4 1st cutting blade 5 2nd cutting blade 10 Wafer 12 Line to be divided 12a Laser grooving 13 Chip 16a, 16b Calf 17 Laser braming 21 Imaging means 22 Reporting means 32 Edge extraction means 33 Histogram Creation means 34 Peak area extraction means 35 Chipping area recognition means 36 Error determination means 37 Determination means

Claims (6)

A chipping detection method in a dicing apparatus that divides a wafer that has been laser-grooved along a dividing line dividing a plurality of chips with a cutting blade along the laser grooving line,
An imaging step of setting the amount of light so that the kerf portion formed by the cutting blade is white and the surrounding laser grooving portion is black, and imaging the division planned line after dicing by the cutting blade with an imaging unit;
An edge extraction step of extracting the edge position of the laser grooving area and the edge position of the kerf area by edge recognition processing on the image captured by the imaging means;
A histogram creating step of creating a histogram relating to the luminance distribution of the image data of each pixel in the laser grooving region in a predetermined range where the edge position is extracted;
A peak area extraction step of extracting the brightest first peak area from the laser grooving area in the predetermined range based on the luminance distribution in the created histogram;
A chipping region recognition step of recognizing a portion continuing to the edge position of the kerf region in the extracted first peak region as a chipping region;
A chipping detection method comprising: An error determination step of determining a chipping error when the size of the chipping region recognized in the chipping region recognition step exceeds a predetermined value;
A notification step for notifying that when the error determination step determines a chipping error;
The chipping detection method according to claim 1, further comprising:   When the peak value of the luminance distribution in the histogram created in the histogram creation step is one, or when the extracted first peak region does not have a portion that is continuous to the edge position of the kerf region The chipping detection method according to claim 1, further comprising a determination step of determining that there is no chipping. A chipping detection device provided in a dicing device that divides a wafer that has been laser-grooved along a dividing line dividing a plurality of chips with a cutting blade along the laser grooving line,
An imaging means for setting the amount of light so that the kerf portion formed by the cutting blade is white and the surrounding laser grooving portion is black, and imaging the division planned line after dicing by the cutting blade;
Edge extraction means for extracting the edge position of the laser grooving area and the edge position of the kerf area by edge recognition processing on the image imaged by the imaging means;
A histogram creating means for creating a histogram relating to the luminance distribution of the image data of each pixel in the laser grooving region in a predetermined range from which the edge position is extracted;
Peak area extraction means for extracting the brightest first peak area from the laser grooving area in the predetermined range based on the luminance distribution in the created histogram;
A chipping region recognition means for recognizing a portion continuing to the edge position of the kerf region in the extracted first peak region as a chipping region;
A chipping detection apparatus comprising: An error determination unit that determines a chipping error when the size of the chipping region recognized by the chipping region recognition unit exceeds a predetermined value;
Informing means for notifying that when the error judging means determines that a chipping error has occurred;
The chipping detection apparatus according to claim 4, further comprising:   When the peak value of the luminance distribution in the histogram created by the histogram creating means is one, or when there is no portion that is continuous with the edge position of the kerf region in the extracted first peak region 6. The chipping detection apparatus according to claim 4, further comprising a determination unit that determines that there is no chipping.

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