CN106273011B

CN106273011B - Cutting device

Info

Publication number: CN106273011B
Application number: CN201610325679.0A
Authority: CN
Inventors: 时本育往; 吉田圭吾
Original assignee: Mitsuboshi Diamond Industrial Co Ltd
Current assignee: Mitsuboshi Diamond Industrial Co Ltd
Priority date: 2015-06-29
Filing date: 2016-05-17
Publication date: 2020-09-08
Anticipated expiration: 2036-05-17
Also published as: KR102493063B1; JP2017013255A; TW201702197A; CN106273011A; JP6520466B2; TWI703101B; KR20170002277A

Abstract

The invention provides a cutting device which can rapidly and reliably detect whether a substrate is successfully cut through a cutting process. The present invention relates to an apparatus for cutting a substrate along a scribe line, configured to cut the substrate by lowering a cutting blade to a predetermined lowering stop position in a state where the substrate is placed on a stage such that a scribe line extending direction coincides with a cutting edge extending direction of the cutting blade, and an imaging device capable of repeatedly shooting the substrate while the cutting blade starts to be lowered, wherein each time a shot image is obtained, a cut detection device determines whether the substrate is successfully cut based on whether a determination index value generated based on the obtained image exceeds a predetermined threshold value.

Description

Cutting device

Technical Field

The present invention relates to a cutting apparatus for substrate cutting, and more particularly, to detection of substrate cutting in the cutting apparatus.

Background

Generally, a process for manufacturing a flat display panel, a solar cell panel, or the like includes a step of dividing a substrate (mother substrate) including a brittle material, such as a glass substrate, a ceramic substrate, or a semiconductor substrate. The following methods are widely used for the said breaking: a scribe line is formed on the surface of the substrate using a scribing tool such as a diamond tip or a cutter wheel, and a crack (vertical crack) is extended from the scribe line in the thickness direction of the substrate. When the scribe line is formed, the vertical crack may be completely extended in the thickness direction to cut the substrate, but the vertical crack may be only partially extended in the thickness direction. In the latter case, the dicing process is performed after the scribe line is formed. The cutting treatment is generally as follows: the substrate is cut along the scribe line by pressing down a cutting blade that is in contact with the substrate along the scribe line to completely advance the vertical crack in the thickness direction.

As a cutting device used for the cutting process, various types of cutting devices are known (for example, see patent document 1).

[ background Art document ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. 2004-131341

Disclosure of Invention

[ problems to be solved by the invention ]

When a conventional cutting apparatus such as that disclosed in patent document 1 is used in a mass production process, a cutting process is generally performed on a substrate manufactured under the same conditions and having scribe lines formed thereon based on the same cutting conditions. The cutting conditions are determined on the premise of reliably cutting the substrate, but there is a possibility that the substrate cannot be cut even by the cutting process due to variations in scribe line formation depth, chipping of the cutting blade, or the like.

Conventionally, it has been difficult to find the occurrence of such a problem unless all the cutting processes are performed on one substrate and the substrate is carried out from the cutting apparatus. When the above-described problem occurs, the substrate must be subjected to the cutting process again. Such a countermeasure becomes a main cause of a reduction in yield.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cutting apparatus capable of quickly and reliably detecting whether or not a substrate is successfully cut by a cutting process.

[ means for solving problems ]

In order to solve the above problem, the invention of claim 1 is characterized in that: a device for cutting a substrate having a scribe line formed on one main surface side along the scribe line, the device comprising: a stage on which the substrate is placed in a horizontal posture; a cutting blade provided above the table so as to be movable forward and backward relative to the table; an imaging device capable of imaging the substrate placed on the stage; and a breaking detection device that detects breaking of the substrate based on a result of the imaging by the imaging device; and the apparatus is configured to cut the substrate along the scribe line by lowering the cutting blade to a predetermined lowering stop position in a state where the substrate is placed on the stage such that the scribe line extending direction coincides with the cutting edge extending direction of the cutting blade; and the image pickup device is capable of repeatedly picking up an image of the substrate at a predetermined time interval while the cutting blade starts to descend; the breaking detection means determines whether the substrate is successfully broken based on whether a determination index value generated based on the acquired image exceeds a predetermined threshold value every time the image pickup means acquires the captured image.

The invention of claim 2 is the cutting device according to claim 1, characterized in that: the breaking detection means generates the determination index value based on a difference image between the reference image and a newly acquired captured image, with the captured image initially acquired by the imaging means as the reference image.

The invention according to claim 3 is the cutting device according to claim 2, characterized in that: the determination index value is a variance value of pixel values of all pixels of the difference image.

The invention of claim 4 is the cutting device according to any one of claims 1 to 3, characterized in that: when it is determined that the substrate is divided based on the determination index value generated using the latest captured image, the subsequent capturing by the imaging device is stopped.

The invention of claim 5 is the cutting device according to any one of claims 1 to 4, characterized in that: the substrate is determined not to be cut when the cutting-off detection means does not determine that the determination index value exceeds the threshold value even though the cutting-off blade is lowered to a predetermined lowering stop position.

The invention of claim 6 is the cutting device according to any one of claims 1 to 5, characterized in that: the image pickup device is two image pickup devices provided separately from each other, and the dividing detection device is configured to generate the determination index values individually for the images picked up by the two image pickup devices, compare the determination index values with the threshold value, and determine that the substrate is divided when each of the determination index values exceeds the threshold value.

The invention of claim 7 is the cutting device according to any one of claims 1 to 6, characterized in that: the platform is transparent, the camera device is arranged below the platform, and the camera device shoots the substrate through the platform.

[ Effect of the invention ]

According to the inventions of claims 1 to 7, whether or not the substrate is successfully divided can be determined quickly and reliably.

Drawings

Fig. 1 is a diagram showing a main part of a cutting apparatus 100 according to an embodiment of the present invention.

Fig. 2 is a diagram showing a main part of the cutting apparatus 100 according to the embodiment of the present invention.

Fig. 3 is a diagram showing a flow of the breaking detection processing.

Fig. 4 is a time-series diagram in the case where the breaking of the substrate W is detected in the breaking detection process.

Fig. 5(a) and (b) are schematic diagrams showing stepwise progress of the cutting process.

Fig. 6 is a schematic view showing a cutting process in stages.

Fig. 7(a) and (b) are schematic diagrams showing stepwise progress of the cutting process.

Fig. 8(a) and (b) are schematic diagrams showing differential images.

Fig. 9(a) and (b) are schematic views showing the vicinity of the cutting blade 2 and the substrate W after the completion of the cutting and the photographed image IM3 at that time.

Detailed Description

< cutting device >

Fig. 1 and 2 are diagrams showing a main part of a cutting apparatus 100 according to an embodiment of the present invention. The cutting device 100 includes: a stage 1 for placing a substrate W in a horizontal posture; a cutting blade 2 for cutting the substrate W by pressing the substrate W; and a chuck 3 for fixing the substrate mounted on the stage 1. The cutting device 100 is a device as follows: the substrate W on which the scribe line SL is formed in advance is subjected to a cutting process using the cutting blade 2, and a crack (vertical crack) is stretched in the thickness direction of the substrate W from the scribe line SL, thereby cutting the substrate W along the scribe line SL.

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

Note that, although fig. 1 and the following drawings show a form in which only 1 scribe line SL is formed on the substrate W, a plurality of scribe lines SL are usually formed on one substrate W for the sake of simplicity of illustration and convenience of description.

In fig. 1 and 2, when the arrangement relationship of the stage 1, the cutting blade 2, and the substrate W is shown, a right-hand xyz coordinate is given, in which the longitudinal direction of the cutting blade 2 is an x-axis direction, a direction perpendicular to the x-axis direction in a horizontal plane is a y-axis direction, and a vertical direction is a z-axis direction. Accordingly, fig. 1 is a yz side view of the periphery of the stage 1 of the cutting apparatus 100, and fig. 2 is a view including a zx side view of the periphery of the stage 1.

The stage 1 includes a transparent member such as quartz glass, for example, and a substrate W is placed on a horizontal upper surface 1a thereof. The substrate W is placed on the surface plate 1 in such a manner that a main surface (scribe line forming surface) Wa on the side where the scribe line SL is formed is in contact with the upper surface 1a, and the extending direction of the scribe line SL is aligned with the extending direction of the cutting edge 2a of the cutting blade 2, and is fixed to the surface plate 1 by the chuck 3.

The cutting blade 2 is made of, for example, a super steel alloy, partially stabilized zirconia, or the like, and as shown in fig. 1, has a cutting edge 2a having a substantially triangular shape in a cross section perpendicular to the longitudinal direction of the cutting blade 2 at a vertically lower portion thereof. The cutting edge 2a is formed by two cutting surfaces which approximately form an angle of about 15-60 degrees.

The cutting device 100 further includes two cameras 4(4a and 4b) vertically below the stage 1. The camera 4 is, for example, a CCD (Charge Coupled Device) camera. The two cameras 4(4a and 4b) are arranged at a distance from each other in the x-axis direction on a vertical plane (zx plane) including the cutting blade 2 (more specifically, the blade edge 2 a). Each camera 4 is disposed vertically upward, and can take an image of the substrate W placed on the stage 1, more specifically, above the transparent stage 1, through the transparent stage 1.

Preferably, the two cameras 4(4a and 4b) are arranged so that the distance from the closest end of the scribe line SL extending along the cutting blade 2 is smaller than the distance between the cameras. However, the imaging range of each camera 4 is sufficiently small with respect to the size of the substrate W, and only a part of the substrate W including a part of the scribe line SL is included in the imaging range.

Further, the illumination devices 5(5a, 5b) are provided in a form attached to the cameras 4. The illumination device 5 is disposed so as to irradiate illumination light vertically upward. As the illumination device 5, it is preferable to use a ring-shaped illumination provided so as to surround each camera 4, for example, but other illumination devices may be used.

The camera 4 (and the illumination device 5) is used for performing the breaking detection process in the following embodiment. The camera 4 may be used for positioning the cutting position.

Hereinafter, for convenience, the two cameras 4(4a and 4b) may be collectively referred to as left and right cameras 4 according to the arrangement illustrated in fig. 2.

Further, although not shown in fig. 1, the cutting device 100 includes a control unit 10, a deck moving mechanism 11, a cutting blade lifting mechanism 12, an input operation unit 13, and a display unit 14, as shown in fig. 2.

The control unit 10 is a unit responsible for operation control of each unit of the cutting apparatus 100 and a breaking detection process described below, and is realized by a computer or the like, for example. The control unit 10 includes a cutting execution processing unit 21 and a breaking detection processing unit 22 as functional components thereof. The cutting execution processing unit 21 is a unit responsible for controlling the operation of each unit of the cutting processing. The cutting detection processing section 22 is a site responsible for a cutting detection process for detecting whether or not the substrate W is successfully cut by the cutting process.

The stage moving mechanism 11 is a mechanism for moving the stage 1 in a horizontal plane (xy plane). Specifically, the translation movement in the y-axis direction and the rotation movement with the vertical direction as the rotation axis can be performed. The table moving mechanism 11 operates in accordance with a control instruction from the cutting execution processing unit 21, thereby moving the position of the cutting target and aligning the scribe line SL with respect to the cutting blade 2.

The cutting blade lifting mechanism 12 is a mechanism for vertically lifting the cutting blade 2 during the cutting process. By operating the cutting blade elevating mechanism 12, the cutting blade 2 can be freely advanced and retracted with respect to the substrate W placed on the stage 1. Generally, in accordance with a control instruction of the cutting execution processing unit 21, the cutting blade elevating mechanism 12 lowers the cutting blade 2 as indicated by an arrow AR1 in fig. 1, and abuts on a position above the scribe line SL on the non-scribe line formation surface Wb of the substrate W, which is the opposite surface of the scribe line formation surface Wa, thereby cutting the substrate W along the scribe line SL.

More specifically, in the cutting process, the cutting blade 2 (more precisely, the cutting edge 2a thereof) is lowered from a predetermined initial position z-z 0 to a stop position (lowering stop position) set at a height position z-z 2 lower than the height position z-z 1 of the non-scribe line formation surface Wb. The distance | z 2-z 0| from z0 to z2 is referred to as the pushing amount of the cutting blade 2.

The input operation unit 13 is configured as follows: including, for example, a keyboard, a mouse, a touch panel, etc., and is used for a user of the cutting apparatus 100 to input various execution instructions, processing conditions, etc., to the cutting apparatus 100.

The display unit 14 is a display for displaying a processing menu, an operation state, and the like of the cutting apparatus 100.

< breaking detection processing >

Next, the breaking detection process performed by the cutting apparatus 100 having the above-described configuration will be described. The breaking detection process of the present embodiment is roughly as follows: during the execution of the cutting process, the two cameras, i.e., the left and right cameras 4, are used to continuously acquire (capture and capture) images of the substrate W at predetermined time intervals, and whether or not the substrate W is cut is determined based on the acquired image contents.

Fig. 3 is a diagram showing a flow of the breaking detection processing. Fig. 4 is a time-series diagram in the case where the breaking of the substrate W is detected in the breaking detection process.

First, in order to perform the cutting process, the substrate W is placed on and fixed to the stage 1 in advance, and in a positioned state, the cutting blade elevation mechanism 12 lowers the cutting blade 2 from its initial position z, z0, in the negative z-axis direction in response to an operation instruction from the cutting execution processing unit 21 (step S1).

In synchronization with the start of lowering of the cutting blade 2, the separation detection processing unit 22 gives an execution instruction to the left and right cameras 4 to acquire images at a predetermined time interval. The left and right cameras 4 responding to the execution instruction irradiate illumination light with the illumination devices 5(5a, 5b), respectively, and acquire the 1 st captured image (step S2), and thereafter acquire the i (i) th captured image (S4) at set time intervals with i 2 (step S3) as an initial value until it is determined that the substrate W is divided (step S3).

Then, each time the left and right cameras 4 acquire the i-th (i ═ 2, 3, 4, · · · ·) captured image, the separation detection processing unit 22 performs a process of determining whether or not the substrate W has been separated, with the captured image as a target (step S5).

The determination process is performed as follows: for each of the photographed images acquired by the left and right cameras 4, the 1 st photographed image is individually used as a reference image, and it is determined whether or not there is a difference from the i-th photographed image acquired last. Specifically, a difference image between the 1 st captured image and the i-th captured image is generated, and it is determined whether or not a determination index value generated based on the pixel value of the difference image exceeds a predetermined reference (threshold) for both of the difference images from the left and right cameras 4 (step S6).

Various measures can be taken into consideration for the setting method of the determination index value, and in the present embodiment, the variance (σ) of the pixel values of all the pixels of the difference image is set²) As a determination index value, a threshold value is set for the variance value. The threshold values are preset as: it is assumed that if a differential image in the case where the substrate W is cut along the scribe line SL by the cutting blade 2, a variance value which should be exceeded is usually assumed.

The reason why the determination is made based on the imaging results of the two cameras 4 that are separated from each other on the left and right sides is that if it is determined that a break has occurred at the position imaged by these cameras 4, it is considered that a break has substantially occurred between the two positions, and the break of the substrate W can be detected without imaging the entire substrate W (or the entire scribe line SL).

If it is determined that the determination index values of both the left and right sides exceed the threshold value (YES in step S6), it is determined that the substrate W has been divided successfully (step S7). The precondition of the determination is: since the substrate W is not changed during the time when the break is not generated, the i-th photographed image should be identical to the 1 st photographed image, and after the break is generated, the photographed image becomes different from the 1 st photographed image due to the different state of the substrate W.

Fig. 4 illustrates a case where the breaking is determined to be successful (a case where breaking is detected) when i is equal to N. At the time point when the determination is made, the image acquisition by the left and right cameras 4 is stopped. That is, at the time point when it is determined that the substrate W is divided based on the newly captured image, the subsequent capturing by the left and right cameras 4 is stopped. However, even after the substrate W is divided, the cutting blade 2 continues to descend to reach a predetermined descent stop position (z-z 2), and then returns to the initial position.

If it is not determined that the determination index values of the left and right sides exceed the predetermined reference (threshold) (NO in step S6), and if the cutting blade 2 reaches the descent stop position (YES in step S8), it is determined that the cutting is not performed (failure of cutting) although the operation for cutting (cutting operation) is completed (step S9). In this case, the pushing amount is set again so that the lowering stop position (z: z2) becomes lower, and then the cutting process is performed again. In addition, when it is not determined that both the left and right determination index values exceed a predetermined reference (threshold), both the left and right determination index values may not reach the reference, or only one of them may reach the reference. The latter corresponds to a case where the substrate W is only partially divided. The position of the cutting blade 2 is specified by, for example: the cutting detection processing section 22 acquires a pulse value of an encoder, not shown, provided in the cutting blade lifting mechanism 12, a signal supplied from a position sensor for detecting the height position of the cutting blade 2, not shown, provided in the cutting device 100, and the like.

When it is not determined that the determination index values of both the left and right sides exceed the predetermined reference (threshold) (NO in step S6), and the cutting blade 2 does not reach the descent stop position (NO in step S8), the cutting operation is not completed normally. Therefore, when the preset processing upper limit time has not elapsed after the cutting blade 2 starts to descend (NO in step S10), i is set to i +1 (step S11), and the next image acquisition is performed by the left and right cameras 4.

Here, the processing upper limit time is a time during which the cutting blade 2 is supposed to reach the lowering stop position until the time elapses after the cutting blade 2 starts to be lowered, if the lowering operation of the cutting blade 2 is normal (regardless of whether or not the cutting is successful), and is set in consideration of a pressing amount set in advance at the time of the cutting operation and a speed at which the cutting blade 2 is lowered by the cutting blade lifting mechanism 12.

Therefore, when the processing upper limit time has elapsed (YES in step S10), the cutting execution processing unit 21 stops the cutting process and the substrate detection processing unit 22 also stops the substrate detection process, assuming that some abnormality has occurred in the lowering state of the cutting blade 2. Then, the operator appropriately confirms the state of the cutting blade 2 or the cutting blade lifting mechanism 12. The presence or absence of the elapse of time from the start time of the cutting process is determined by the substrate detection processing unit 22 appropriately referring to the value of a timer, not shown, provided in the cutting apparatus 100.

Next, the determination process will be described in more detail together with a change in the progress status of the cutting process. Fig. 5 to 7 are schematic diagrams showing the cutting process in stages, and fig. 5 and 7 also schematically show captured images acquired by the camera 4. Fig. 8 is a schematic view of a differential image.

Fig. 5(a) shows a state where the cutting blade 2 does not reach the substrate W after starting to descend. As long as this state is achieved, the captured image IM1 is obtained as an image showing only the case where the scribe line SL is present at the center position of the substrate W, as shown in fig. 5 (b).

In fig. 1, the cutting edge 2a is schematically shown in a form in which two rake faces intersect, but as shown in fig. 5(a), the cutting edge 2a is a curved surface having a certain radius of curvature at the tip portion.

In the present embodiment, from the viewpoint of speeding up the determination process, only a partial region of the imaging range (a partial range of the imaged image IM1 in fig. 5 (b)), more specifically, a vicinity of a formation region of the scribe line SL where the break is generated in the imaged image is set as the process target region ROI for generating the difference image, and the difference image may be generated only for the process target region ROI.

As long as the cutting blade 2 does not reach the substrate W, a captured image substantially identical to the captured image IM1 shown in fig. 5(b) is repeatedly acquired as the i-th captured image. That is, there is almost no difference in the image contents between the 1 st captured image and the i-th captured image. Therefore, a differential image during a period in which the cutting blade 2 does not reach the substrate W is generated as an image in which the pixel values of all pixels are substantially 0. Fig. 8(a) schematically shows the differential image D1 in this case. The difference image D1 shown in fig. 8(a) is viewed as a full-white image in the illustrated case, but the actual difference image D1 is merely obtained as an image in which pixels having a luminance set as the luminance when the difference value is 0 are spread over the entire surface. The variance value of the difference image D1 is not determined to exceed the threshold. Therefore, as long as a captured image like the captured image IM1 is obtained, the determination of NO is continued in step S6. The case where the determination in step S8 is YES and the result reaches step S9 means a case where only the captured image substantially identical to the captured image IM1 is repeatedly acquired until the cutting blade 2 reaches the lowering stop position.

The cutting blade 2 which is further lowered is brought into contact with the substrate W as shown in fig. 6. If the cutting blade 2 is further lowered after the contact with the substrate W, the cutting blade 2 applies a force to the substrate W, and the vertical crack CR extends from the scribe line SL in the substrate W as indicated by an arrow AR2 in fig. 6. Then, as the vertical crack CR extends, the substrate W is pulled to the left and right, and finally divided into two single pieces W1 and W2 as shown in fig. 7 (a). At this time, the two single pieces W1, W2 are separated from each other in the right-left direction so as to spread by the cutting blade 2, and a gap G is formed between the two pieces. Therefore, as shown in fig. 7(b), the captured image IM2 at this time is obtained in the form of an image showing a state in which a gap G exists between the two single sheets W1, W2.

Fig. 8(b) shows a difference image D2 (with respect to the processing target region ROI) from the captured image IM1 shown in fig. 5(b) in the case where the captured image IM2 shown in fig. 7(b) is obtained as the i-th captured image. In the difference image D2 shown in fig. 8(b), a region RE1 corresponding to the scribe line SL appearing in the captured image IM1 and a region RE2 corresponding to the gap G appearing in the captured image IM2 are formed so as to sandwich the region. The differential image D2 shown in fig. 8(b) is a schematic image at all times, and in the actual differential image D2, the region RE1 and the region RE2 are simply regions having different luminance levels from the peripheral region including the other.

When the difference image D2 is obtained, the variance value as the determination index value thus calculated exceeds the threshold value. If the captured images such as the captured image IM2 are obtained in the left and right cameras 4, the determination index values on both the left and right sides exceed the threshold value, and it is determined that the division has succeeded.

In the present embodiment, since the left and right cameras 4 take images of the cutting blade 2 at predetermined intervals after the cutting blade 2 starts to descend, and whether or not the division occurs is determined directly based on the taken images, when the division occurs, the division situation can be grasped in almost real time, more specifically, when the cutting blade 2 is in a state in which the two pieces W1, W2 generated by the division are spread. In addition, even when the cutting blade 2 reaches the lowering stop position but the cutting is not successful, the above situation can be immediately grasped immediately after the cutting operation is performed, and therefore, the re-cutting after the press-in amount is changed can be performed promptly.

Further, it is considered that, even if the image is not continuously taken immediately after the cutting blade 2 starts to descend as in the above-described procedure, it is possible to determine whether or not the substrate W is successfully cut by taking an image of the state of the substrate W after the cutting blade 2 reaches the descent stop position. However, the present inventors have made extensive studies and have found that it is difficult to determine whether or not the cleavage is successful in the above form.

Fig. 9 is a view schematically showing the vicinity of the substrate W (actually, the singals W1 and W2) and the cutting blade 2 after the completion of the division shown in order to explain this point, and a captured image IM3 obtained by the camera 4 at this time.

The cutting blade 2 that has reached the lowering stop position after dividing the substrate W is raised by the cutting blade raising and lowering mechanism 12. Thus, if the cutting blade 2 is separated from the sheets W1 and W2, the sheets W1 and W2 that have spread right and left by the cutting blade 2 are close to each other as shown in fig. 9(a), and the gap G between the two is eliminated. The single pieces W1 and W2 are in contact with each other at the cut surface, that is, at the portion where the scribe line SL and the vertical crack CR are formed. Fig. 9(b) schematically shows a captured image IM3 obtained by the camera 4 in this case. As shown in fig. 9(b), the captured image IM3 is obtained as an image in which the vertical crack CR is superimposed on the portion where the scribe line SL was originally formed, but is similar to the captured image IM1 shown in fig. 5(b) as an image. Therefore, even if a difference image is generated in the same order as described above and a threshold-based determination is performed, it is difficult to reliably determine whether or not the division has succeeded.

In contrast, in the case of the present application, by appropriately defining the imaging time interval of the camera 4, the cut-off that cannot be captured in the k-th captured image (more specifically, the state in which the cutting blade 2 laterally spreads the two individual pieces W1, W2 generated by the cut-off of the substrate W) can be captured in the k + 1-th captured image that is acquired next, and therefore, the presence or absence of the cut-off of the substrate W can be reliably determined by the determination process based on the k + 1-th captured image.

The imaging time interval of the camera 4 is preferably set to about 10msec to 50msec, for example, when the lowering speed of the cutting blade 2 is 50mm/sec to 150mm/sec and the pushing amount is 0.1mm to 0.2 mm.

As described above, according to the cutting apparatus of the present embodiment, when the cutting process for extending the vertical crack along the scribe line is performed, the substrate to be cut is shot at predetermined time intervals in synchronization with the cutting process, and whether or not the substrate is cut is determined based on the shot results, whereby it is possible to quickly and reliably determine whether or not the substrate is successfully cut.

< example of variation >

In the above embodiment, the image is taken by two cameras which are separated from each other, but instead, all or most of the range in which the scribe line SL is formed may be taken by one camera (image pickup device), and the determination process may be performed based on the result of the image taking. Alternatively, three or more cameras may be used.

In the above-described embodiment, the judgment as to whether or not the division is performed is made based on the difference image between the 1 st captured image and the i-th captured image, but instead, the captured image may be directly used as the judgment target.

[ description of symbols ]

1 platform

2 cutting off the knife

2a knife tip

3 chuck

4(4a, 4b) camera

5(5a, 5b) Lighting device

10 control part

11 platform moving mechanism

12 cut-off knife lifting mechanism

13 input operation unit

14 display part

21 cutting execution processing part

22 dividing detection processing part

100 cutting device

CR vertical crack

D1 and D2 differential images

G gap

IM 1-IM 3 captured images

ROI-processed object region

SL scribe line

W substrate

Wa line forming surface

Wb non-scribe line forming surface

Claims

1. A cut-off device, characterized by:

a device for cutting a substrate having a scribe line formed on one main surface side along the scribe line, the device comprising:

a stage on which the substrate is placed in a horizontal posture;

a cutting blade provided above the table so as to be movable forward and backward relative to the table;

an imaging device capable of imaging the substrate placed on the stage; and

a breaking detection device that detects breaking of the substrate based on a result of the imaging by the imaging device; and is

The cutting device is configured to cut the substrate along the scribe line by lowering the cutting blade to a predetermined lowering stop position in a state where the substrate is placed on the stage such that an extending direction of the scribe line coincides with an extending direction of a cutting edge of the cutting blade; and is

The imaging device can repeatedly take images of the substrate at a predetermined time interval while the cutting blade starts to descend;

the breaking detection means determines whether the substrate is successfully broken based on whether a determination index value generated based on the acquired image exceeds a predetermined threshold value every time the image pickup means acquires the captured image,

the image pickup devices are two image pickup devices provided separately from each other,

the dividing detection means individually generates the determination index values for the images captured by the two imaging means, compares the determination index values with the threshold value, and determines that the substrate is divided when the respective determination index values exceed the threshold value.

2. The cut-off device of claim 1, wherein:

the dividing detection device generates the determination index value based on a difference image between the reference image and a newly acquired captured image, with the captured image initially acquired by the imaging device as the reference image.

3. The cut-off device of claim 2, wherein:

the determination index value is a variance value of pixel values of all pixels of the difference image.

4. The cutoff device according to any one of claims 1 to 3, characterized in that:

when it is determined that the substrate is divided based on the determination index value generated using the latest captured image, subsequent capturing using an imaging device is stopped.

5. The cutoff device according to any one of claims 1 to 3, characterized in that:

the substrate is determined not to be cut when the cutting-off detection means does not determine that the determination index value exceeds the threshold value even though the cutting-off blade is lowered to a predetermined lowering stop position.

6. The cutoff device according to any one of claims 1 to 3, characterized in that:

the platform is transparent, and the platform is transparent,

the camera device is arranged below the platform,

the imaging device images the substrate through the stage.