JP6460267B2 - Break device - Google Patents

Description

  The present invention relates to a break device used for dividing a substrate, and more particularly to inspection of a cutting edge of a break blade used in a break device.

  A manufacturing process of a flat display panel or a solar cell panel generally includes a step of dividing a substrate (mother substrate) made of a brittle material such as a glass substrate, a ceramic substrate, or a semiconductor substrate. For such cutting, a technique is widely used in which a scribe line is formed on the substrate surface using a scribe tool such as a diamond point or a cutter wheel, and a crack (vertical crack) is extended from the scribe line in the thickness direction of the substrate. Yes. When the scribe line is formed, the vertical crack may be completely extended in the thickness direction and the substrate may be divided, but the vertical crack may be only partially extended in the thickness direction. In the latter case, a break process is performed after the scribe line is formed. The break process is generally to push down the break blade abutted on the substrate in a manner along the scribe line, so that the vertical crack is completely advanced in the thickness direction, thereby dividing the substrate along the scribe line. It is.

  Various types of break devices are known as break devices used for such break processing (see, for example, Patent Document 1).

JP 2004-131341 A

  For example, when a conventional break device as disclosed in Patent Document 1 is used in a mass production process, the same break conditions are usually applied to a substrate manufactured under the same conditions and formed with a scribe line. Break processing is performed under Such a break condition is determined on the premise that the substrate is surely divided, but if the break blade is chipped (defect), there is a possibility that the substrate is not divided even by the break processing.

  In order to avoid such a failure, the break blade needs to be replaced when a predetermined number of breaks have been performed, or it is necessary to periodically inspect for breakage. Since the operation is performed with the apparatus stopped, it has been an impediment to improving the operating rate of the break apparatus. In the former case, a break blade that can still be used may be replaced, which is one of the factors that increase the manufacturing cost.

  This invention is made | formed in view of the said subject, and it aims at implement | achieving the break apparatus which can test | inspect the blade edge | tip, without removing a break blade.

In order to solve the above problems, the present invention is an apparatus for breaking a substrate having a scribe line formed on one main surface side along the scribe line, and the table on which the substrate is placed in a horizontal posture. And a break blade provided above the table so as to be movable forward and backward, an image pickup means arranged so as to be able to take an image of the cutting edge of the break blade, and the image pickup means based on the image pickup result. Inspection means for inspecting the cutting edge of the break blade for chipping, the table is transparent, the image pickup means is provided below the table, and the image pickup means passes through the table. The blade edge is imaged. By lowering the break blade to a predetermined descent stop position in a state where the substrate is placed on the table so that the extending direction of the scribe line and the extending direction of the cutting edge of the break blade coincide with each other, The cutting edge inspection unit is configured to divide the substrate along the scribe line, and the cutting edge inspection unit generates a determination index generated based on the captured image of the cutting edge acquired by the imaging unit. It is good also as determining the presence or absence of the chip | tip of the said blade edge | tip based on whether it exceeds.

Before SL imaging means comprises provided movably along the longitudinal direction of the break edge, and the cutting edge so as to image by the predetermined range every time the pitch moved by a predetermined distance in the longitudinal direction cage, said cutting edge inspection unit, whenever said imaging means acquires a captured image, and generates the determination indicator based on the captured image, the presence or absence of chipping of the cutting edge is determined, it is also possible.

If the determination indicator generated using the captured image captured immediately near exceeds the criterion, the said cutting edge inspection means determines that lacks the cutting edge has occurred, imaging means subsequent It is also possible to stop the imaging.

If the determination index of all of the images captured by the previous SL imaging unit is not determined either that even exceeds the criterion, the cutting edge test means are not missing occurs in the cutting edge It is good also as judging.

Before Symbol edge inspection means, the captured image to extract a missing candidate area from the binarized result to generate an area value of the missing candidate region as the judgment indicator, the area value exceeds a predetermined threshold value In some cases, it may be determined that the cutting edge is chipped.

Before Symbol edge inspection means, from the captured image, and generates a brightness profile is a profile representing the brightness change as the judgment indicator in a cross section perpendicular to the longitudinal direction of the break edge in the profile, the moving average of the profile It may be determined that the cutting edge is chipped when there is a portion exceeding a threshold determined based on the threshold.

Before Symbol table is transparent, the imaging means comprises provided below the table, the imaging means for imaging the cutting edge through the table, it is also possible.

According to the present invention, since it is possible to determine whether or not the break blade edge is chipped based on one or a plurality of imaging results obtained by imaging the break blade in the break device, the chip of the blade edge is missing. The presence or absence of can be determined quickly and reliably.

FIG. 2 is a view showing a main part of a break device 100. FIG. 2 is a view showing a main part of a break device 100. It is a figure which shows the flow of a blade edge | tip inspection process. It is a figure which shows typically about the imaging position by the camera 4 in a blade edge | tip inspection process. This is a captured image IM1 when the cutting edge 2a is chipped. This is an image IM2 in which the missing region RE certified in the determination process for the captured image IM1 is indicated by a closed curve. This is an image IM3 of the blade edge 2a in which no chipping occurs. It is the figure which attached | subjected the xy coordinate of the pixel value with respect to image IM4 which shows the process target area | region ROI in the captured image IM1. It is a figure of the brightness profile produced | generated based on image IM4. It is a figure of the brightness profile produced | generated based on image IM3.

<Break device>
1 and 2 are diagrams showing a main part of a break device 100 according to an embodiment of the present invention. The break device 100 fixes a table 1 for placing the substrate W in a horizontal position, a break blade 2 that divides the substrate W by being pressed against the substrate W, and a substrate placed on the table 1. The chuck 3 is provided. The break device 100 extends a crack (vertical crack) from the scribe line SL in the thickness direction of the substrate W by performing a break process on the substrate W on which the scribe line SL is formed in advance using the break blade 2. Thus, the apparatus divides the substrate W along the scribe line SL.

  The substrate W is made of a brittle material such as a glass substrate, a ceramic substrate, or a semiconductor substrate. The thickness and size are not particularly limited, but typically, a thickness of about 0.4 mm to 1.0 mm or a size of about 50 mm to 300 mm is assumed.

  1 and the subsequent drawings show a mode in which only one scribe line SL is formed on the substrate W, but this is for convenience of illustration and convenience of description, A large number of scribe lines SL are formed on the substrate W.

  In FIGS. 1 and 2, in showing the positional relationship of the table 1, the break blade 2, and the substrate W, the longitudinal direction of the break blade 2 is the x-axis direction, and the direction perpendicular to the x-axis direction is in the horizontal plane. A right-handed xyz coordinate system with the y-axis direction and the vertical direction as the z-axis direction is attached. Accordingly, FIG. 1 is a yz side view around the table 1 of the break device 100, and FIG. 2 also includes a zx side view around the table 1.

  The table 1 is made of a transparent member such as quartz glass, for example, and the substrate W is placed on the horizontal upper surface 1a. The substrate W is configured such that the main surface (scribe line forming surface) Wa on which the scribe line SL is formed is in contact with the upper surface 1a, and the extending direction of the scribe line SL is set to the cutting edge 2a of the break blade 2. Are placed on the table 1 and fixed to the table 1 by the chuck 3.

  The break blade 2 is made of, for example, a super steel alloy or partially stabilized zirconia, and as shown in FIG. 1, a cutting edge whose cross section perpendicular to the longitudinal direction of the break blade 2 has a substantially triangular shape is formed on the vertical lower portion thereof. 2a. The blade edge 2a is generally formed by two blade surfaces having an angle of about 15 ° to 60 °.

  In addition, the break device 100 includes a camera 4 vertically below the table 1. The camera 4 is a CCD camera, for example. The camera 4 is arranged in a vertical plane (zx plane) including the break blade 2 (more specifically, the blade edge 2a). The camera 4 is arranged vertically upward, and can image the break blade 2 above the transparent table 1, more specifically the blade edge 2 a through the transparent table 1.

  However, the imaging range of the camera 4 is sufficiently small with respect to the size of the break blade 2, and when the break blade 2 is imaged, the imaging range includes only a part of the cutting edge 2a of the break blade 2. It has become.

  Moreover, the illumination means 5 is provided in the aspect attached to the camera 4. The illumination means 5 is arranged so as to irradiate illumination light vertically upward. As the illumination means 5, ring illumination provided in a manner surrounding the camera 4 is a suitable example, but other forms may be used.

  The camera 4 (and the illuminating means 5) is used when performing a cutting edge inspection of the break blade 2 in a manner described later. The camera 4 may be used in positioning the break position.

  Further, although not shown in FIG. 1, as shown in FIG. 2, the break device 100 includes a control unit 10, a table moving mechanism 11, a break blade lifting mechanism 12, an input operation unit 13, A display unit 14 and a camera moving mechanism 23 are provided.

  The control unit 10 is a part responsible for operation control of each part of the break device 100 and blade edge inspection described later, and is realized by, for example, a computer. The control unit 10 includes a break execution processing unit 21 and a blade edge inspection processing unit 22 as functional components. The break execution processing unit 21 is a part responsible for operation control of each unit related to the break processing. The blade edge inspection processing unit 22 is a part responsible for processing for inspecting the blade edge 2 a of the break blade 2.

  The table moving mechanism 11 is a mechanism that moves the table 1 in the horizontal plane (in the xy plane). Specifically, translational movement in the y-axis direction and rotational movement with the vertical direction as the rotation axis can be performed. The table moving mechanism 11 operates in accordance with the control instruction of the break execution processing unit 21 to move the break target position and align the scribe line SL with respect to the break blade 2.

  The break blade raising / lowering mechanism 12 is a mechanism for raising and lowering the break blade 2 in the vertical direction during the break process. By operating the break blade raising / lowering mechanism 12, the break blade 2 can be moved forward and backward with respect to the substrate W placed on the table 1. Generally speaking, the break blade raising / lowering mechanism 12 lowers the break blade 2 as shown by an arrow AR1 in FIG. 1 according to the control instruction of the break execution processing unit 21, and the substrate W which is the opposite surface of the scribe line forming surface Wa. The substrate W is divided along the scribe line SL by bringing the scribe line non-formation surface Wb into contact with the position above the scribe line SL.

  More specifically, during the break process, the break blade 2 (strictly, the blade edge 2a) is stopped from a predetermined initial position at a height position lower than the height position of the scribe line non-formation surface Wb. It is lowered until it reaches the position (descent stop position). The distance from the initial position to the descent stop position is referred to as the pushing amount of the break blade 2.

  Moreover, the break blade raising / lowering mechanism 12 is used also in the case of a blade-tip inspection process. That is, during the blade edge inspection process, the break blade 2 (strictly, the blade edge 2a) is an inspection position (imaging height) determined from a predetermined initial position z = z0 to a height position z = z1 in the vicinity of the table 1. Until it reaches

  The input operation unit 13 is a part made up of, for example, a keyboard, a mouse, a touch panel, etc., for the user of the break device 100 to input various execution instructions and processing conditions to the break device 100.

  The display unit 14 is a display for displaying a processing menu and an operation state of the break device 100. The display unit 14 also displays the result of the blade edge inspection process as appropriate.

  The camera moving mechanism 23 is a mechanism for moving the camera 4 together with the illumination means 5 associated therewith in the x-axis direction, which is the longitudinal direction of the break blade 2. In the break device 100, the camera 4 is moved by a predetermined distance in the x-axis direction by the camera moving mechanism 23 by a predetermined distance, and the imaging by the camera 4 is repeated each time the movement is performed, so that the imaging range is small as described above. While using the camera 4, the entire blade edge 2 a of the break blade 2 can be imaged.

<Blade inspection process>
Next, the blade edge inspection process performed in the break device 100 having the above-described configuration will be described. The blade edge inspection process can be performed at any timing when the break operation is not performed. In the cutting edge inspection process according to the present embodiment, generally, image acquisition (capture, capture) of the cutting edge 2a by the camera 4 is sequentially performed from one end side of the break blade 2, and based on the content of the acquired image, It is determined whether or not the cutting edge 2a is chipped.

  FIG. 3 is a diagram showing the flow of the blade edge inspection process. FIG. 4 is a diagram schematically showing an imaging (image acquisition) position by the camera 4 in the blade edge inspection process.

  First, in a state where the substrate W is not placed on the table 1, the break blade lifting mechanism 12 lowers the break blade 2 from its initial position z = z0 to the inspection position (imaging height) z = z1 (step S1). ).

  When the break blade 2 is placed at the imaging height, the blade edge inspection processing unit 22 gives an execution instruction to the camera 4 and the camera moving mechanism 23 so as to acquire an image. As shown in FIG. 4, the camera moving mechanism 23 responding to the execution instruction takes i = 1 (step S2) as an initial value and takes the i-th (i = 1, 3, 4,...) Imaging position. The camera 4 is moved (pitch feed) (step S3). Each time the camera 4 moves to each imaging position, the camera 4 acquires a captured image while irradiating illumination light with the illumination means 5. Thereby, the i-th captured image is obtained at the i-th imaging position (step S4).

  Each time the i-th captured image is obtained by the camera 4, the blade edge inspection processing unit 22 determines whether or not the blade edge 2 a is chipped with respect to the captured image (step S <b> 5).

  In the determination process, it is determined whether or not the determination index generated based on the captured image acquired by the camera 4 exceeds a predetermined determination criterion (threshold value) (step S6).

  Various ways of setting the determination index can be considered, but in the present embodiment, the determination process is performed using one of the two determination indexes described later.

  When it is determined that the determination index exceeds a predetermined determination criterion (threshold) (YES in step S6), it is determined that the cutting edge 2a is missing (step S7).

  FIG. 4 illustrates a case where it is determined that a chipped image has occurred in a captured image of i = n (n is a natural number). In this case, the cutting edge 2a is missing within the imaging range of the nth captured image. When such a determination is made, the acquisition of an image by the camera 4 is stopped. That is, when it is determined that the cutting edge 2a is chipped based on the most recently captured image, the subsequent imaging by the camera 4 is stopped. In this case, the break blade 2 is normally replaced.

  Note that in general, chipping of the blade edge 2a is an event that can occur randomly at an arbitrary position in the longitudinal direction of the break blade 2, so it is determined that the chipping has occurred in the determination process for the first captured image. In some cases, it may be determined that a defect has occurred in the determination process for a plurality of captured images.

  If it is not determined that the determination index exceeds a predetermined determination criterion (threshold) (NO in step S6), and there is an imaging position where imaging has not been completed (NO in step S8), i = i + 1 (Step S9), the camera 4 performs imaging at the next imaging position.

  If it is not determined that the determination index exceeds a predetermined determination criterion (threshold) (NO in step S6), and imaging has been completed at all imaging positions (YES in step S8), that is, In the determination based on all of the last captured images from the first captured image captured by the camera 4, if it is not determined that the determination index exceeds a predetermined determination criterion (threshold), the cutting edge 2a includes It is determined that no chipping has occurred (step S10).

  The progress of the blade edge inspection process (result of sequential determination process) and the result are displayed on the display unit 14 in an appropriate manner.

  By performing the cutting edge inspection process according to the above procedure, in the break device 100, the chip 4a of the break blade 2 is missing based on one or a plurality of captured images obtained by the camera 4 capturing the break blade 2. The presence or absence can be determined quickly and reliably without removing the break blade 2.

<Judgment process>
Next, regarding the above-described determination process performed by the blade edge inspection processing unit 22, more specifically, the generation of a determination index and the content of the determination process based on the determination index will be described. As described above, in the present embodiment, two types of determination processes using different determination indexes are possible. Hereinafter, they will be described sequentially. In any aspect, the determination processing is performed by utilizing the fact that the portion where the chipping occurs is an area having relatively high brightness in the captured image (which appears relatively white in the image).

(First aspect)
In this aspect, all closed regions with relatively high brightness are extracted from the captured image by a known image processing method, and the area of each closed region is calculated as a determination index. Then, when there is a closed region where the area value exceeds the threshold, the closed region is recognized as a missing region, and it is determined that the cutting edge 2a is missing in the missing region.

  5 to 7 are diagrams for explaining the determination processing according to this aspect. FIG. 5 is a captured image IM1 when the cutting edge 2a is chipped. Further, FIG. 6 shows an image IM2 in which the missing region RE recognized in the determination process for the captured image IM1 shown in FIG. 5 is shown by a closed curve. FIG. 7 is an image IM3 of the cutting edge 2a that is not chipped and is shown for comparison.

  In the determination processing according to this aspect, the entire captured image may be a processing target. However, when the region where the blade edge 2a exists is limited in the captured image, a part of the captured image is processed. A processing target area may be set, and only the processing target area ROI may be set as an image processing target. Also in the present embodiment, as shown in FIG. 5, a rectangular area extending left and right in the center of the drawing is set as the processing target area ROI, and the subsequent processing is performed only for pixels in the processing target area ROI. It is targeted. 6 and 7 also show only the processing target region ROI (the same applies to FIG. 8 described later).

  As illustrated in FIG. 7, in the image captured by the camera 4, the blade edge 2 a that is not chipped is projected as a linear region with relatively high brightness. This is a substantially triangular shape in cross-section as described above, and imaging is performed while illuminating illumination light by the illumination means 5 on the cutting edge 2a arranged so that the apex portion of the triangle faces vertically downward. By doing.

  On the other hand, in the image captured by the camera 4, a region where a defect is generated is also projected as a region with relatively high brightness. However, as can be seen from FIG. 5 and FIG. 6, it has been confirmed in advance that the region where the chipping occurs tends to be wider than the region where the chipping does not occur. This is due to the fact that the shape of the substantially triangular shape in cross section is broken in the region where the chipping occurs, and the sharpness is inferior to the region where the chipping is not generated.

  Therefore, in this aspect, the binarization processing is performed on the captured image IM1 (actually the processing target region ROI) to acquire the light / dark levels of all the pixels, and the light level pixels (bright pixels) are continuous. All the closed regions are extracted as missing candidate regions, and the area (number of pixels) is calculated. At that time, dark level pixels (dark pixels) that exist in a manner surrounded by the extracted closed region are incorporated into the closed region. Then, the calculated area value of the missing candidate area is compared with a predetermined threshold value, and if there is a missing candidate area having an area value exceeding the threshold value, the edge 2a is missing in the captured image acquisition range. It is determined that

  From the background, the defect candidate area includes those derived from the part of the cutting edge 2a where no defect occurs, but the area of the defect candidate area in such a part is actually a defect. If the threshold value is set appropriately in advance, the presence or absence of a large missing candidate region whose area exceeds the threshold value, if the threshold value is set appropriately in advance. Thus, it is possible to determine whether or not the cutting edge 2a is missing in the captured image acquisition range that is the target of the determination process.

(Second aspect)
In this aspect, a profile (brightness profile) representing a change in brightness in a cross section perpendicular to the longitudinal direction of the break blade 2 is obtained from the captured image, and the profile is used as a determination index. And when there exists a location which exceeds the threshold value in the profile, it is determined that the cutting edge 2a is missing.

  FIG. 8 is a diagram in which xy coordinates of pixel values are attached to the image IM4 indicating the processing target region ROI in the captured image IM1 with respect to the portion where the cutting edge 2a is missing as illustrated in FIG. As shown in FIG. 8, the processing target region ROI has xa pixels from x = 1 to x = xa in the x-axis direction, and yb pixels from y = 1 to y = yb in the y-axis direction. Suppose there are pixels.

  In this aspect, binarization processing is performed on an image that is a generation target of a brightness profile, and the brightness levels of all pixels are acquired, and x = 1 for each of y = j (j = 1 to yb). The number (number of pixels) of bright level pixels (bright pixels) is counted (counted) in a range of ~ x = xa. A plot of the count values with respect to y = 1 to y = yb is a brightness profile. In other words, the brightness profile is a data set of y = j and the count value there for j = 1 to yb.

  FIG. 9 is a diagram of a lightness profile generated based on the image IM4. FIG. 10 is a diagram of a brightness profile generated based on the image IM3 of FIG. 7 which is an image showing a processing target region ROI in a captured image of a portion where no missing portion is shown for comparison. . In both FIG. 9 and FIG. 10, the lightness profile is indicated by a bold solid line (indicated as “count value” in the figure).

  However, in both FIG. 9 and FIG. 10, the brightness profile is shown only for the range of Δy in the vicinity of the blade edge 2a shown in FIG. 8 instead of the entire range of y = 1 to y = yb.

  When the brightness profile is obtained in the above-described manner, next, several points around y = j (y = j−k, j− (k−1),..., J−1, j, j + 1,..., j + (k−1), j + k, k is a natural number), an average value is obtained, and the average value is plotted for y = 1 to y = yb. Get. In both FIG. 9 and FIG. 10, the moving average profile is indicated by a thin solid line (displayed as “moving average” in the figure).

  Further, a threshold profile is obtained by adding a predetermined fixed value (offset value) to the average value in each of y = 1 to y = yb constituting the moving average profile. In both FIG. 9 and FIG. 10, the threshold profile is indicated by a broken line (displayed as “threshold” in the figure).

  Then, in the range near the blade edge 2a, the brightness profile and the threshold profile are compared at the same y-coordinate value, and if there is a y-coordinate in which the data point of the brightness profile exceeds the data point of the threshold profile, the brightness profile is It is determined that the cutting edge 2a is missing in the imaging range of the obtained captured image. In the lightness profile shown in FIG. 9, it is determined that a defect has occurred because the data point of the lightness profile exceeds the data point of the threshold profile when “detected location” is written. On the other hand, in the lightness profile shown in FIG. 10, since all y-coordinates are below the threshold profile, it is determined that there is no chipping in the blade edge 2a in the imaging range of the captured image from which the lightness profile is obtained. The

  As described above, according to the break device according to the present embodiment, whether or not the cutting edge of the break blade is chipped based on one or a plurality of imaging results obtained by imaging the break blade. Since it can be determined, the presence or absence of a chip on the blade edge can be determined quickly and reliably without removing the break blade from the break device.

<Modification>
In the above-described embodiment, one camera (image pickup means) picks up the entire cutting edge 2a of the break blade 2 instead of performing repeated image pickup by sequentially shifting the pitch of one camera. However, a mode in which the determination process is performed based on the imaging result may be employed. However, in such a case, it is necessary to use a camera having a sufficient resolution when performing the determination process. In such a case, the captured image may be divided into a plurality of parts in the longitudinal direction of the break blade 2, and the determination process may be performed sequentially or in parallel on each of the divided parts.

  Alternatively, it may be an aspect in which two or more cameras are used, each of which performs imaging in an aspect in which the imaging range is shared, and determination processing is performed in parallel on the imaging results. In such a case, for each camera, the pitch movement within the imaging range in charge and the imaging after the movement may be repeated.

DESCRIPTION OF SYMBOLS 1 Table 2 Break blade 2a Blade edge 3 Chuck 4 Camera 5 Illumination means 10 Control part 11 Table moving mechanism 12 Break blade raising / lowering mechanism 13 Input operation part 14 Display part 21 Break execution process part 22 Cutting edge inspection process part 23 Camera movement mechanism 100 Break apparatus SL scribe line W substrate Wa scribe line formation surface Wb scribe line non-formation surface

Claims (1)

On the other hand, a device that breaks a substrate having a scribe line formed on the main surface side along the scribe line,
A table on which the substrate is placed in a horizontal position;
A break blade provided above the table so as to be movable forward and backward with respect to the table;
Imaging means arranged to be able to image the cutting edge of the break blade;
A blade edge inspection means for inspecting the presence or absence of chipping in the blade edge of the break blade based on one or a plurality of captured images of the blade edge obtained by imaging by the imaging means;
With
The table is transparent, the imaging means is provided below the table, and the imaging means images the blade edge via the table ;
Break device characterized by that.