JP2013152153A - Film thickness irregularity detection device and method, and coating device with film thickness irregularity detection device and film thickness irregularity detection method of coating film formed on substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film thickness irregularity detection device capable of discovery without fail immediately after a coating is applied even as to vertical streaks and lateral streaks accompanied by a slight film thickness irregularity only, and a coating device having the film thickness irregularity detection device.SOLUTION: The film thickness irregularity detection device comprises: an irradiation part 3 for irradiating a coating film on a substrate 10 with light of a specific irradiation pattern; a light reception part 4 for receiving reflection light reflected on a surface of the coating film; and a determination part for comparing a light reception pattern received by the light reception part with the specific irradiation pattern. The determination part includes: an image comparison section for comparing the light reception pattern with the irradiation pattern; a displacement-extracted image generation section for extracting a displacement resulting from comparison of the light reception pattern with the irradiation pattern by the image comparison section; an integration section for integrating an area of dotted displacement-extracted images from a displacement-extracted image; and an integrated displacement area determination section for determining whether or not a total value of the integrated displacement-extracted area is larger than a predetermined reference value.

Description

  The present invention relates to an apparatus and a method for detecting film thickness unevenness of a coating film formed on a substrate, and a coating apparatus and a coating method for detecting film thickness unevenness of the coating film immediately after forming the coating film on a substrate.

  A flat panel display such as a liquid crystal display or a plasma display uses a coating liquid (referred to as a coating substrate) coated with a coating liquid in order to form a color film or a transparent film on a substrate made of glass or the like. This coating substrate is formed by a coating apparatus that uniformly coats the coating solution. In other words, the coating apparatus includes a stage on which the substrate is placed and a coating unit that discharges the coating liquid. The substrate and the coating unit are relatively moved while discharging the coating liquid from the base portion of the coating unit. By moving, a coating liquid film (coating film) having a predetermined thickness is formed on the substrate.

  The coating substrate formed by such a coating apparatus is subjected to a film thickness unevenness check for confirming whether or not the coating film does not include film thickness unevenness such as stripes or grains. Specifically, immediately after the coating process for forming the coating film on the substrate, the film thickness is inspected in a state before the coating film is dried by the drying process and thinned (for example, Patent Document 1). .

  In the apparatus used for this unevenness inspection, an irradiation unit that outputs light of a specific irradiation pattern to the coating film formed on the substrate is used to receive the reflected light reflected on the surface of the coating film. Thus, the quality of the coating film formation state is judged by comparing the light receiving pattern of the received reflected light with a specific irradiation pattern (for example, Patent Document 2).

  FIG. 10 is an image diagram of an image picked up by a conventional film thickness nonuniformity inspection apparatus, in which a pattern reflected by a substrate having no film thickness unevenness is received. That is, the black and white stripe pattern irradiated from the irradiation part is imaged as the bright part 43a and the dark part 43b.

  FIG. 11 is an image diagram of an image picked up by a conventional film thickness nonuniformity inspection apparatus, in which a pattern reflected by a substrate having film thickness unevenness (vertical stripes) is received. For this reason, the portion having no film thickness unevenness is imaged as the bright portion 43a and the dark portion 43b as in the diagram shown in FIG. On the other hand, in the portion 43 s with uneven film thickness (vertical stripe), the bright portion 43 a and the dark portion 43 b are imaged with the stripe pattern distorted.

  FIG. 12 is an image diagram after the shift extraction process in the conventional film thickness nonuniformity inspection apparatus, in which an image with no film thickness unevenness is compared with an image with film thickness unevenness, and there is a difference. Only the portion is extracted as “deviation extraction pixel 43z”. For convenience of explanation, the image image made up of this shift extraction pixel represents the boundary of the black and white pattern with a broken line, and indicates at what position and in what size the shift extraction pixel 43z exists in the light receiving pattern. Yes.

  In the conventional film thickness nonuniformity inspection device, various values for extracting the shift extraction pixel 43z are set as appropriate values as inspection parameters, and each size of the extracted shift extraction pixel 43z is set in advance. It was determined whether or not there was uneven film thickness by determining whether or not it was larger than the reference value. While flat panel displays are rapidly becoming cheaper and there are strong demands for cost reductions, demands for higher definition and color reproducibility are also increasing, and demands for inspection of film thickness unevenness are severe. It has become to. For this reason, a coated substrate including a film thickness unevenness exceeding the reference value is not only inspected after passing through the drying process after coating (so-called after coating drying), but also before the drying process immediately after coating. Uneven inspection is performed. Then, the substrate immediately after coating is judged whether it can proceed to the drying process as a non-defective product in the film thickness non-uniformity inspection just after coating, and if it is defective, measures are taken such as rejecting and repairing before drying. .

JP 2005-337857 A JP 2010-234237 A

  In a conventional inspection immediately after coating, the substrate to be inspected is determined for each area with respect to the shift extraction pixels appearing in the vicinity of the border between the bright portion 43a and the dark portion 43b of the stripe pattern, and a large area shift extraction is performed. If there was a pixel, it was judged as a defective product. On the other hand, even if there are a group of small pixels with a small area, if each area is small, it will be treated as a noise component in the process of misalignment extraction. The substrate was not rejected.

  However, such a small area shift existing in a group may be caused by vertical stripes or horizontal dunes with only slight film thickness unevenness. In strict inspection after coating and drying, as vertical stripes and horizontal dunes, May be detected. For this reason, even in the inspection immediately after coating, it is hoped that slight film thickness unevenness due to vertical stripes and horizontal dans will show the same detection accuracy (that is, maintain consistency) as the strict inspection after drying. It was rare.

Therefore, the present invention can detect even vertical stripes and horizontal dunes with only slight film thickness unevenness immediately after coating, and can maintain consistency with strict inspection after coating and drying. Provided are a detection apparatus and a coating apparatus including the film thickness unevenness detection apparatus.

In order to solve the above problems, the invention described in claim 1
An irradiation unit that emits light of a specific irradiation pattern toward the coating film formed on the substrate,
A light receiving unit that receives the reflected light of the specific irradiation pattern reflected by the surface of the coating film,
A film thickness provided with an inspection unit that determines the quality of the coating film formation state by comparing the light receiving pattern of the reflected light received by the light receiving unit with a reference pattern corresponding to the specific irradiation pattern An unevenness detection device,
The inspection unit
An image comparison unit for comparing the light receiving pattern and the reference pattern;
A deviation extraction image generation unit that compares the light reception pattern with the reference pattern in the image comparison unit and generates an image composed of pixels extracted as a deviation part as a deviation extraction image;
A shift extraction pixel area integration unit that integrates the areas of the pixels extracted in the shift extraction image existing in a predetermined region of the shift extraction image as a shift extraction pixel area integration value;
An uneven film thickness detection apparatus comprising: an integrated shift area determination unit that determines whether the shift extraction pixel area integrated value is greater than a set reference value.

The invention described in claim 5
Irradiating light of a specific irradiation pattern toward the coating film formed on the substrate;
Receiving the light irradiated in the irradiation step and reflected by the surface of the coating film,
A method for detecting unevenness in film thickness, comprising: an inspection step for determining whether a coating film is formed by comparing a pattern received in the light receiving step with a reference pattern corresponding to the specific irradiation pattern. ,
The inspection step includes
An image comparison step for comparing the light receiving pattern and the reference pattern;
A shift extraction image generation step of generating an image composed of pixels extracted as a shift portion by comparing the light receiving pattern and the irradiation pattern in the image comparison step;
A shift extraction area integration step of integrating the area of the shift extracted image existing in a predetermined region of the shift extraction image as a shift extraction pixel area integration value;
An integrated film thickness non-uniformity detecting method comprising: determining whether or not the integrated value of the extracted pixel area is larger than a set reference value.

Since the film thickness unevenness detection apparatus and method are used,
In the past, small film thickness unevenness portions scattered on a predetermined irradiation pattern as treated as noise are also treated as a group of film thickness unevenness or film thickness unevenness candidates, and the coating film formation state Pass / fail can be judged.

The invention described in claim 2
It is a film thickness nonuniformity detection apparatus of Claim 1, Comprising:
The inspection unit
A first reference value registration unit for registering a set reference value of the integrated deviation area determination unit as a first reference value;
When the deviation extraction pixel area integrated value is larger than the first reference value,
The area of the extracted pixels outside the predetermined area, which is present continuously with the extracted pixels existing in the predetermined area of the deviation extracted image, is added to the integrated value of the extracted deviation pixel area. A shift extraction pixel area additional integration unit, which is set as a shift extraction pixel area additional integration value,
A second reference value registration unit for registering a setting reference value for the shift extraction pixel area additional integrated value as a second reference value;
It is determined whether the deviation extraction pixel area additional integrated value is greater than the second reference value.
A film thickness nonuniformity detection apparatus comprising an integrated deviation area second determination unit.

The invention described in claim 6
The film thickness unevenness detection method according to claim 5,
The inspection step includes
Read the first reference value, which is the criterion value for the integrated deviation area,
When the total value of the accumulated deviation areas is larger than the registered first reference value,
The area of the extracted pixels outside the predetermined area, which is present continuously with the extracted pixels existing in the predetermined area of the deviation extracted image, is added to the integrated value of the extracted deviation pixel area. A shift extraction pixel area additional integration step, which is set as a shift extraction pixel area additional integration value,
Read a second reference value that is a determination reference value for the deviation extraction pixel area additional integrated value,
It is determined whether the deviation extraction pixel area additional integrated value is greater than the second reference value.
And a film thickness non-uniformity detection method characterized by comprising an integrated deviation area second determination step.

If the film thickness unevenness detection apparatus and method are used,
Even if the displacement extraction pixel corresponding to the vertical streak / horizontal dan that you want to detect exists across the boundary of the specified area, the first reference value Is set low, and the second reference value can be compared with the deviation extraction pixel area additional integrated value including a group of deviation extraction pixels that exist outside the predetermined region. By doing so, it is possible to prevent detection of unevenness in film thickness and reliably determine the quality of the coating film formation state.

The invention according to claim 3
3. The film thickness unevenness detection apparatus according to claim 1, wherein the predetermined area is an area extending in a coating direction or a direction orthogonal thereto. It is a coating device with a device.

The invention described in claim 7
The film thickness unevenness detection method according to claim 1 or 2, wherein the predetermined region is a region extending in a coating direction or a direction perpendicular thereto.

If the film thickness unevenness detection apparatus and method are used,
It is possible to accurately determine whether or not the coating film is formed due to unevenness in the film thickness extending in one direction, which is called a vertical stripe or horizontal dan.

The invention according to claim 4
A substrate mounting portion, a coating nozzle, a moving mechanism,
A coating apparatus with a film thickness unevenness detection apparatus comprising the film thickness unevenness detection apparatus according to any one of claims 1 to 3,
The coating apparatus with a film thickness unevenness detector, wherein the reflected light reflected by the surface of the coating film is reflected light reflected by the surface of the coating film applied by the coating nozzle.

The invention according to claim 8 provides:
Placing the substrate on the substrate platform;
A step of relatively moving the substrate mounting portion and the coating nozzle;
Forming a coating film on the substrate by discharging a coating liquid from a coating nozzle while performing the relative movement; and
Detecting uneven thickness of the coating film formed on the substrate in the coating step,
The film thickness unevenness detection step is the film thickness unevenness detection method according to any one of claims 5 to 7, and is a film thickness unevenness detection method for a coating film formed on a substrate.

If the coating apparatus with a film thickness unevenness detection apparatus and a film thickness unevenness detection method for a coating film formed on a substrate are used,
It is possible to determine whether or not film thickness unevenness has occurred on the coated substrate immediately after coating. Therefore, if it is determined that film thickness unevenness has occurred, the coating operation is immediately stopped, or abnormal information is notified when the coated substrate is transferred to the downstream process. Since it is possible to take measures to take out, loss in the manufacturing process can be reduced and cost can be reduced.

Even vertical stripes and horizontal dunes with only slight film thickness unevenness can be reliably detected immediately after coating, and consistency with strict inspection after coating and drying can be maintained.

It is a side view which shows an example of the form which embodies this invention. It is a system configuration figure showing an example of the form which embodies the present invention. In an example of the form which embodies the present invention, it is an image figure after carrying out shift extraction processing. It is a frequency distribution diagram of the pixel which shifted and extracted based on the picture imaged in an example of the form which embodies the present invention. It is a flowchart in an example of the form which embodies the present invention. In an example of the form which embodies this invention, it is an image figure showing the difference by the presence or absence of a shift | offset | difference extraction process. It is a top view which shows another example of the form which embodies this invention. It is a side view which shows another example of the form which embodies this invention. It is a system block diagram which shows another example of the form which embodies this invention. It is an image figure of the image imaged in the conventional film thickness nonuniformity inspection apparatus. It is an image figure of the image imaged in the conventional film thickness nonuniformity inspection apparatus. It is an image figure after performing the shift | offset | difference extraction process in the conventional film thickness nonuniformity inspection apparatus.

DESCRIPTION OF EMBODIMENTS Embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing an example of a form embodying the present invention.
Hereinafter, in each figure, the three axes of the orthogonal coordinate system are X, Y, and Z, the XY plane is the horizontal plane, and the Z direction is the vertical direction. In particular, in the Z direction, the direction of the arrow is represented as the top, and the opposite direction is represented as the bottom.

  The film thickness unevenness detection device 1 includes a substrate placement unit 2, an irradiation unit 3, a light receiving unit 4, an inspection unit 5, and a control unit 9. Here, a substrate 10 in which a color film is applied to glass will be described as an example of a substrate to be inspected.

  The substrate platform 2 is configured to include a substrate platform 21 on which the substrate 10 is placed, and the surface of the substrate platform 21 is provided with pores and fine grooves. It is connected to a vacuum source such as a vacuum pump via a switching valve. Therefore, the substrate 10 placed on the substrate platform 21 can be fixed and held on the substrate platform 21 by setting the pores and the narrow grooves to a negative pressure state. Further, the substrate mounting table 21 is attached to the frame portion (not shown) of the film thickness unevenness detection device 1 directly or via the moving mechanism 23.

  The irradiation unit 3 includes an irradiation unit 31 that emits light of a specific irradiation pattern toward the substrate 10, and a light amount adjustment unit 38 that is connected to the irradiation unit 31 and adjusts the intensity of light emitted from the irradiation unit 31 ( 2). The irradiation unit 31 includes a housing part 32, a light emitting part 33, and a partial light shielding part 34, and light emitted from the light emitting part 33 disposed in the housing part 32 is partially shielded. It arrange | positions so that it may irradiate toward the test object area | region 10f of the board | substrate 10 through the part 34. FIG. The partial light shielding part 34 is composed of a light transmission part and a light shielding part corresponding to white and black stripe patterns as described with reference to FIG. Therefore, the part emitted from the light emitting part 33 and passing through the light transmitting part is imaged as the bright part 43a, and the part shielded by the light shielding part is imaged as the dark part 43b. At this time, the irradiation optical axis 37 of the light emitted from the irradiation unit 31 is arranged at an angle θ with respect to the substrate 10.

  The light receiving unit 4 includes an imaging camera 41 and a lens 42, and the imaging camera 41 and the lens 42 are disposed toward the inspection target region 10 f of the substrate 10. At this time, the observation optical axis 47 of the imaging camera 41 and the lens 42 is arranged at an angle θ with respect to the substrate 10. Further, the imaging camera 41 is installed so as to be focused on the partial light-shielding portion 34 of the illumination unit, and is irradiated from the irradiation unit 31 and reflected by the surface of the coating film formed on the substrate 10 to be inspected. Can be acquired as a light receiving pattern.

  As will be described in detail later, the inspection unit 5 can perform a comparison process between the light reception pattern reflected on the substrate and a reference pattern corresponding to a specific irradiation pattern to determine whether the coating film is formed. The reference pattern is a light receiving pattern observed by the imaging camera 41 when the coating film formed on the substrate 10 does not include film thickness unevenness, and is regarded as having no film thickness unevenness or no film thickness unevenness. It is also possible to acquire and register using a reference work that can be performed, or to define and register a design reference pattern.

[System configuration]
FIG. 2 is a system configuration diagram illustrating an example of an embodiment embodying the present invention. In the film thickness unevenness detection apparatus 1 described above with reference to FIG. 1, the substrate mounting unit 2, the irradiation unit 3, the light receiving unit 4, A state in which each device of the inspection unit 5 is connected to each device of the control unit 9 is shown.

  The control unit 9 includes a control computer 90, an information input unit 91, an information output unit 92, a reporting unit 93, an information recording unit 94, and a device control unit 95. An information input unit 91, an information output unit 92, a notification unit 93, an information recording unit 94, and a device control unit 95 are connected to the control computer 90.

  The control computer 90 is for controlling the film thickness unevenness detection apparatus 1 of the present invention in an integrated manner. Specifically, the control computer 90 reads out and executes a program registered in the information recording means 94 and various setting parameters used for detection of film thickness unevenness, and issues a control command to the control device control unit 95. By performing, it is comprised so that the thickness nonuniformity concerning this invention can be detected.

Examples of the control computer 90 include a computer equipped with a numerical operation unit such as a microcomputer, a personal computer, or a workstation.
Examples of the information input unit 91 include a keyboard, a mouse, and a switch.
Examples of the information output unit 92 include an image display display and a lamp.
Examples of the reporting means 93 include a buzzer, a speaker, and a lamp that can alert the worker.

The information recording means 94 registers a setting reference value, details of which will be described later, a setting value of a predetermined area, a first reference value, and a second reference value. A specific form of the information recording means 94 is exemplified by a semiconductor recording medium, a magnetic recording medium, a magneto-optical recording medium, and the like, such as a memory card and a data disk.
Examples of the device control unit 95 include devices called programmable controllers and motion controllers.

  The device control unit 95 is connected to the moving mechanism 23 and can relatively move the irradiation unit 3 and the light receiving unit 4 and the substrate 10 at a predetermined speed based on a command from the control computer 90.

  The device control unit 95 is connected to the light amount adjustment unit 38 and can transmit a predetermined set value to the light amount adjustment unit 38. Therefore, the device control unit 95 can control the amount of light emitted from the irradiation unit 31 based on a command from the control computer 90.

  The control unit 9 further includes an image processing unit 96. The image processing unit 96 is connected to the control computer 90, and the video signals output from the first and second observation units 31 and 32 are input via the image processing unit 96. The image processing unit 96 is generally called a GPU (graphic processing unit), and is installed outside the control computer 90, connected to the housing of the control computer 90, or the control computer 90. The one using the image processing unit is exemplified.

  The image signal output from the imaging camera 41 is input to the control computer 90 via the image processing unit 96. The image processing unit 96 is installed outside the control computer 90, is connected to the housing of the control computer 90, is configured using the image processing unit of the control computer 90, etc. And functions as the inspection unit 5 in the present invention.

[Details of inspection section]
The inspection unit 5 is provided in the image processing unit 96, and includes an image comparison unit, a shift extraction image generation unit, a shift extraction pixel area integration unit, and an integration shift area determination unit. Each unit is configured to correspond to a processing block in a program registered in the image processing unit 96. Specifically, the following processing is performed.

  The image comparison unit compares the light receiving pattern with a reference pattern corresponding to the specific irradiation pattern, and determines whether or not a change has occurred at a location corresponding to each pattern. Specifically, when the light reception pattern and the reference pattern are black and white patterns, a difference calculation process is performed on each pixel at a position corresponding to the light reception pattern captured by the imaging camera 41 and the reference pattern, A processing block is programmed to determine whether the light receiving pattern and the reference pattern are the same white or black, or whether the white and black are different. For this reason, in the light receiving pattern, a pixel having a color different from that of the reference pattern is treated as a portion having a deviation due to uneven thickness. In the image comparison unit, when comparing the reference pattern and the received light pattern, a threshold different from the conventional one is set, and a small deviation that is conventionally processed as noise is detected. The comparison process is performed under (so-called overdetection condition).

  The shift extraction image generation unit generates pixels extracted as a shift portion by the image comparison unit as one image image in correspondence with the observation position of the light reception pattern. Specifically, a so-called labeling process is performed on pixels extracted as a shifted portion in the light receiving pattern imaged by the imaging camera 21, and adjacent pixels are grouped together. Then, the whole corresponding to the position of each pixel in the observation area so that it can be understood in which part in the observation area of the imaging camera 21 the scattered deviation extracted pixels after the labeling process are distributed. The processing block is programmed so that the image is generated as a single image.

FIG. 3 is an image diagram after the shift extraction processing is performed in the example embodying the present invention, and shows the image image generated by the shift extracted image generation unit.
Pixels that have been shifted by the comparison process in the image comparison unit are present in various places in the image diagram as illustrated in FIG. 3 as “shift extracted pixels 43c”. Further, the shift extraction pixels 43c are scattered separately, in addition to the shift extraction pixel group 44 that is slightly scattered, the shift extraction pixel group 45 that is scattered in a straight line, and the line that is densely scattered and scattered. It can be seen as a form like the shift extraction pixel group 46. In FIG. 3, for convenience of explanation, a broken line 43d indicates a boundary portion between the bright portion 43a and the dark portion 43b of the light receiving pattern. In addition, in order to obtain this image, a threshold value different from the threshold value used in the conventional inspection apparatus is set so that more displacement extraction pixels 43c are extracted.

  In the image generated by the shift extraction image generation unit, the entire image corresponding to the position of each pixel in the observation area is divided into several areas, and each divided area is set as a predetermined area. FIG. 3 illustrates one predetermined area 48 out of a plurality of predetermined areas. The predetermined area 48 includes t pixels in the X direction and all pixels in the Y direction. Yes.

  The deviation extraction pixel area integration unit integrates the areas of the pixels 43c that have been extracted and exist in the predetermined region 48, and obtains the deviation extraction pixel area integration value. Specifically, the number of pixels 43c extracted as a shifted portion in the light receiving pattern captured by the imaging camera 21 is within a predetermined area (for example, within a common position X direction range). The number of pixels in the Y direction is counted (added), and the processing block is programmed so that the area is integrated.

  The setting of the predetermined area 48 will be described with a specific example. In the present embodiment, the effective imaging area of the imaging camera 41 is 1000 pixels in the X direction and 750 pixels in the Y direction, and is divided into 100 in the X direction. In this case, the shift extraction image is generated by the shift extraction image generation unit as an image image of X: 1000 pixels × Y: 750 pixels. In addition, the generated shift-extracted image is divided into regions of 10 pixels by dividing 100 in the X direction and 750 pixels without dividing in the Y direction, and X: 10 pixels × Y: 750 pixels. For the image image, the areas of the shift extraction pixels included therein are subjected to integration processing. Such processing is also performed for each predetermined region, and an area integrated value of the shift extraction pixels is calculated for each predetermined region. By doing so, it is possible to treat the small area shift extraction pixels that are present apart from each other in the predetermined region as a group of shift extraction pixel groups.

  In the above description, an example in which the entire image is divided into 100 in the X direction has been described. However, the number of divisions can be changed as appropriate. Further, the predetermined area may be divided in the Y direction.

  The integrated deviation area determination unit compares the deviation extraction pixel area integration value integrated by the deviation extraction pixel area integration unit with a preset reference value, and determines whether it is larger than the setting reference value. Is determined. Specifically, the setting reference value registered and set in the information recording unit 94 is read out and compared with the integrated value of the extracted pixel area. The integrated deviation area determination unit determines that the coating film formation state is bad if the deviation extraction pixel area integration value is larger than the set reference value, and the deviation extraction pixel area integration value is the set reference value. If it is smaller than that, the processing block is programmed so as to determine that the formation state of the coating film is good.

FIG. 4 is a frequency distribution diagram of pixels that are shifted and extracted based on an image captured in an example of an embodiment that embodies the present invention. The horizontal axis corresponds to the shifted and extracted image illustrated with reference to FIG. Is the imaging position X, and the vertical axis indicates the integrated area value N of the extracted pixels in the Y direction within the common X direction range of each imaging position.
The area integrated value N of the shift extracted pixels divided in the X direction and integrated for each predetermined region is compared with the set reference value by the integrated shift area determining unit.

  At this time, if, for example, N0 is set as the setting reference value, the level of N0 (straight line 50) is a threshold for the area integrated value N. Then, the integrated deviation area determination unit determines whether an area integrated value N of deviation extraction pixels in each of the predetermined regions is larger than a set reference value N0, and the area integrated value N is the set reference value N0. If there is no portion exceeding the level, the substrate to be inspected is determined as a non-defective product, and if there is a portion exceeding the set reference value N0, it is determined as a defective product.

  Therefore, to explain with reference to FIG. 3, among the shift extraction pixels 43 c, those that are scattered independently, the shift extraction pixel group 44 that is scattered a little, and the shift extraction pixel group 45 that is scattered in a straight line. Since the integrated area value N is smaller than the set reference value N0, the integrated deviation area determination unit determines that the area is a non-defective product. On the other hand, since the area integrated value N is larger than the set reference value N0 for the portions of the shift extracted pixel group 46 that are densely scattered in a straight line, the integrated shift area determination unit has the uneven thickness. It is determined that there is a defect.

  At this time, if there are a plurality of coating film types and inspection conditions, the setting reference value is registered in association with the type of coating film and the inspection conditions so as to cope with the type switching. In addition, in order to determine whether or not a group of deviation extraction pixel groups has uneven film thickness, the reference value for determining the presence or absence of uneven film thickness with respect to the integrated value of a predetermined area is an inspection apparatus after coating and drying. It is preferable to set so as to agree with the result obtained in (1). By doing so, the accuracy of film thickness unevenness detection according to the present invention can be brought close to the inspection accuracy after coating and drying, and the mutual consistency can be maintained.

  Since the film thickness unevenness detection apparatus 1 has such a configuration, a specific irradiation pattern (reflected in the above example) emitted from the illumination unit 31 of the irradiation unit 3 reflected in the inspection target region on the substrate 10. In other words, a 45-degree diagonal stripe pattern) is imaged by the imaging camera 41 of the light receiving unit 4, and the quality of the coating film formation state is determined by the inspection unit 5 based on the captured image. Can be detected.

  In the conventional inspection apparatus, the pass / fail judgment is performed based on the size of each shift extraction pixel. Therefore, the pass / fail judgment can be easily made if the change in the film thickness unevenness is large. However, it is difficult to determine whether or not the film thickness unevenness caused by vertical stripes and horizontal dunes exists across a plurality of reference patterns.

  However, the film thickness non-uniformity detection apparatus 1 according to the present invention has an area of a shift extraction pixel that exists in a predetermined region even for film thickness non-uniformity caused by vertical stripes and horizontal dunes that exist across a plurality of reference patterns. And the pass / fail judgment is made based on the integrated area value. Therefore, it is suitable for determining whether or not the film thickness has a length in a predetermined direction such as a vertical stripe or a horizontal dan.

[flowchart]
FIG. 5 is a flowchart in an example embodying the present invention, and a series of steps for detecting the film thickness unevenness of the coating film formed on the substrate by applying the present invention are shown for each step. ing.

First, the substrate 10 on which the coating film is formed is placed on the substrate mounting table 21 (s101).
The substrate mounting table 21 is moved to a position where the inspection target area 10f on the substrate 10 can be imaged by the imaging camera 41 with the substrate 10 fixed and held as necessary (s102).
Light is emitted from the illumination unit 31 toward the inspection target region 10f on the substrate 10, and imaging is performed by the imaging camera 41 (s103).

Whether or not to perform the same inspection as the conventional one is selected based on the inspection condition information set and registered in advance (s104).
When performing the same inspection as in the past, the light receiving pattern light imaged by the imaging camera 41 and the pre-registered irradiation pattern light are compared with each other under the appropriate conditions similar to the conventional inspection conditions. Is compared (s111), and the shift extraction image generation unit of the inspection unit 5 extracts a shift portion (s112). Thereafter, the deviation extraction pixel area integration unit of the inspection unit 5 integrates the areas of the pixels extracted in the predetermined area of the deviation extraction image as deviation extraction pixel area integration values. Thereafter, the integrated deviation area determination unit determines whether or not the deviation extraction pixel area integrated value is larger than the set reference value (s114), and if it is larger, treats it as a defective product (s116), otherwise treats it as a non-defective product ( s117).

If it is selected in step s104 that the same inspection as in the prior art is not performed, or after steps s116 and s117, based on information on inspection conditions that have been set and registered in advance (overdetection conditions different from those in the prior art) The light-receiving pattern light imaged by the imaging camera 41 and the irradiation pattern light registered in advance are compared by the inspection unit 5 (s121), and a misaligned portion is extracted (s122).
Thereafter, the deviation extraction pixels in the predetermined area are integrated (s123).
It is determined whether or not the integrated value is larger than the set reference value (s124). If it is larger, it is processed as a defective product (s126), and if not, it is processed as a non-defective product (s127).

  By doing as described above, slight film thickness unevenness due to vertical stripes existing in the Y direction can be accurately detected. In the above description, the slight film thickness unevenness caused by the vertical stripes existing in the Y direction has been described. Similarly, the slight film thickness unevenness caused by the horizontal dan present in the X direction can be detected with high accuracy. it can. By aligning the X direction and the Y direction with the direction of vertical stripes or horizontal dunes that may occur on the coated substrate, slight film thickness unevenness due to the vertical stripes or horizontal dunes can be detected.

  [Modification: Additional processing]

FIG. 6 is an image diagram showing a difference depending on the presence / absence of a deviation extraction process in an example of a form embodying the present invention. FIG. 6A shows an enlarged image of the shift extraction pixel described above with reference to FIG. 3, and the shift-extracted pixel 43 c and the predetermined region 48 are shown. A group of shift extraction pixels corresponding to vertical stripes / horizontal dunes to be originally detected may completely fit in the predetermined area 48, or may cross the boundary line of the predetermined area 48 as shown in FIG. There are cases where it exists.
FIG. 6B is an image diagram showing a shift extraction pixel 43m that overlaps with the predetermined region 48 (that is, within the predetermined region) among the shift extraction pixels 43c. Therefore, in the film thickness unevenness detection apparatus and method according to the present invention as described above, the group of shift extraction pixels corresponding to the vertical stripes / horizontal dunes to be originally detected does not completely fit in the predetermined area 48, and the predetermined area is set. In the case where it exists so as to straddle 48 boundary lines, the integrated displacement extraction pixel area integrated value does not reach the set reference value in the predetermined region and is not determined as a defective product.

  Therefore, in addition to the embodiment described above, the film thickness unevenness detection apparatus according to the present invention is embodied by adding the following configuration, and sets a group of shift extraction pixels corresponding to vertical stripes / horizontal dunes to be originally detected. Even if the boundary line of the predetermined region 48 is straddled, the quality determination is surely performed.

  FIG. 6C is an image diagram showing the shift extraction pixel 43m in the predetermined area 48 and the shift extraction pixel 43p adjacent to the shift extraction pixel 43m among the shift extraction pixels 43c. A state after the re-labeling process is performed on the shift-extracted pixel 43p outside the predetermined area, which exists continuously with the shift-extracted pixel 43m in the predetermined area so as to straddle.

  In the case of this modification, the inspection unit further includes a first reference value registration unit, a deviation extraction pixel area addition integration unit, a second reference value registration unit, and an integrated deviation area second determination unit. . Each unit is configured to correspond to a processing block in a program registered in the image processing unit 96.

  The first reference value registration unit registers a set reference value of the integrated deviation area determination unit as a first reference value. Specifically, if the first reference value is set to N1, as described with reference to FIG. 4, the level (straight line 51) at which the area integrated value N is N1 is a threshold value. Then, the integrated deviation area determining unit determines that the substrate to be inspected is a non-defective product if the area integrated value N does not exceed the level of the set reference value N1, and if there is a part exceeding the level of N1, The processing block is programmed to determine that should make an additional decision.

The shift extraction pixel area addition integration unit is present continuously with the shift extracted pixels existing in a predetermined region of the shift extraction image when it is difficult to judge whether the shift extraction pixel area is only the integration value of the shift extraction pixel area. The area of the extracted pixels out of the predetermined area is additionally integrated with the above-mentioned deviation extraction pixel area integration value, and is acquired as a deviation extraction pixel area addition integration value addition integration. Specifically, the deviation outside the predetermined region exists continuously with the pixel whose deviation is extracted within the predetermined region so as to straddle the boundary line of the region determined to be additionally determined by the integrated deviation area determination unit. The extracted pixels are re-labeled, and the respective pixel areas are integrated. Then, the area value of the pixel extracted by the re-labeling process outside the predetermined area is integrated with the area integrated value of the pixel extracted by the shift within the predetermined area so as to be obtained as an additional integrated value of the extracted pixel area. The processing block is programmed.

  The second reference value registration unit registers a set reference value for the shift extraction pixel area additional integrated value as a second reference value. Specifically, the second reference value registration unit registers a value larger than the first reference value, and the deviation extraction pixel area value after the additional integration becomes a threshold value for judging whether or not the film thickness unevenness is acceptable. The processing block is programmed so that the value is set.

  The integrated deviation area second determination unit determines whether or not the deviation extraction pixel area additional integrated value is larger than the second reference value. Specifically, when the second reference value is set as N2, the integrated deviation area second determination unit determines that the deviation extraction pixel area additional integrated value Nx does not exceed the level of the second reference value (N2). The processing block is programmed so that the substrate to be inspected is determined as a non-defective product, and if there is a portion exceeding the level of N2, the predetermined area is determined as a defective product.

On the other hand, in the film thickness nonuniformity detection method according to the present invention, the additional processing described as the above modification is applied as follows.
First, when the modification example is not applied, it is determined in step s124 whether the area integrated value of the shift extraction pixels is larger than a set reference value. However, when the modification example is applied, Step s124 is set as a preliminary determination step, and further post-processing is added to make a determination to increase the inspection accuracy. In step s123, the pixel areas of the shifted portions in the predetermined region are integrated, and based on the result, it is determined in step s124 whether the integrated area value of the shifted portions is larger than the reference value. However, in this modification, the value used as the determination reference in step s124 is set as the first reference value, and is registered in advance in the first reference value registration unit. Then, the integrated value of the deviation areas obtained in step s123 is compared with the first reference value.

  When the total value of the integrated displacement areas is larger than the registered first reference value, the area of the displacement extraction pixels adjacent to the displacement extraction pixels integrated with the area is further added to the total value. Perform processing to add up. In this case, not only the shift extraction pixels in the predetermined area but also the extracted shift portion is outside the predetermined area, and is integrated as a group of shift extraction pixels. Even if the integrated value of the above includes a value derived from a minute noise component, by adding the adjacent displacement extraction pixels, a displacement extraction pixel that is not a minute noise component and originally derived from unevenness to be detected Can be accumulated more.

  Then, it is determined whether the deviation area integrated value after the additional summation is larger than the second reference value. At this time, the second reference value is registered in advance in the second reference value registration unit so that the second reference value can be consistent with the detection result obtained using the film thickness unevenness detector after drying. It is preferable. By doing so, the accuracy of detecting the film thickness unevenness according to the present invention can be made closer to the inspection accuracy after coating and drying, and the consistency can be maintained.

In addition, the image when there is no film thickness unevenness is prepared by actually preparing a substrate without film thickness unevenness and storing the image captured by the imaging camera 41. Alternatively, an image that is observed when a substrate with no film thickness unevenness is actually imaged may be defined and stored as a reference image.

As described above, if the film thickness unevenness detection apparatus and method to which the above modification is applied are used,
Even if the displacement extraction pixels corresponding to the vertical stripes / horizontal dunes to be detected exist so as to straddle the boundary line of the set predetermined area, even if the displacement extraction pixel area integrated value is halved, the first reference value The threshold value is set low, and compared with the second reference value and the shift extraction pixel area additional integrated value including a group of shift extraction pixels existing outside the predetermined region 48, the coating film formation state Pass / fail can be judged.

[Modification 2: Direction setting of a predetermined area]
In the above description, in applying the present invention, the predetermined region 48 is set for an arbitrary place of the light receiving pattern. Even in such a form, it is possible to detect vertical stripes and horizontal dunes. However, as the unevenness of the film thickness becomes minute, the deviation extraction pixel area integrated value and the deviation extraction pixel area additional integration value may be slightly lower than the set reference value or the first and second reference values. Yes, it may not be judged as bad. That is, the above situation can occur when the predetermined region 48 is set not to extend in the coating direction but to intersect or gradually deviate from the vertical stripe to be detected. Similarly, if the predetermined region 48 is set not to be a region extending in a direction orthogonal to the application direction but to a horizontal Dunn to be detected, in a state where it intersects or gradually deviates, the above situation can occur. .

  Therefore, in applying the present invention, it is more preferable that the predetermined region 48 is a region extending in the application direction or a region extending in a direction orthogonal to the application direction. By doing so, it is possible to more reliably detect vertical stripes and horizontal dunes accompanied by slight film thickness unevenness.

[Coating device with uneven film thickness inspection device]
FIG. 7 is a plan view showing another example of a form embodying the present invention, and FIG. 8 is a side view showing another example of a form embodying the present invention.
The coating apparatus 101 includes an irradiation unit 3, a light receiving unit 4, an inspection unit 5, a relative movement unit 7, a coating unit 8, and a control unit 9.

  The coating apparatus 101 includes a frame portion 112, a guide rail 122 that is attached on the frame portion 112 and extends in the Y direction, and a slider portion that can move on the guide rail 122 at a predetermined speed and stop at a predetermined position. 123. Two pairs of guide rails 122 and slider parts 123 are attached on the frame part 112 with the substrate mounting table 121 interposed therebetween. Further, a portal frame 130 is attached on the pair of slider portions 123 so as to straddle the substrate mounting table 121. An elevating actuator 140 that can move in the Z direction is attached to the portal frame 130, and a coating nozzle 150 is attached to the elevating actuator 140.

  The illumination unit 31 of the irradiating unit 3 and the imaging camera 41 of the light receiving unit 4 constituting the coating apparatus 101 have the same configuration as those of the observation apparatus 1 described above, and are disposed at a position facing the substrate 110w. The light that is emitted from 31 and reflected is observed by the imaging camera 41. Further, the angle formed by the illumination optical axis 37 of the illumination unit 31 and the observation optical axis 47 of the imaging camera 41 with respect to the surface of the substrate 10 is set to the same angle.

The inspection unit 5 and the control unit 9 constituting the coating apparatus 101 include the function of inspecting the film thickness unevenness of the film formed on the substrate, as in the above-described observation apparatus 1, and further, a color film is applied and formed on the substrate 110w. It is configured to be able to.
In addition, the relative movement part 7 in this form is comprised including the slider part 123. FIG.
The application unit 8 includes an elevating actuator 140 and an application nozzle 150.

  The illumination unit 31 has a predetermined length in the width direction (that is, the X direction) of the substrate 110w, and can irradiate the inspection target region 110f on the substrate 110w with light having a specific irradiation pattern. At least one imaging camera 41 is arranged so that the inspection target area 110f on the substrate 110w can be observed.

  Further, a gate-type frame 115 indicated by a broken line is attached to the frame portion 112 side by side with the gate-type frame 130 so as to straddle the substrate 110w and the substrate mounting table 121. A lighting unit 31 and an imaging camera 41 are attached via a not-shown). The portal frame 115, the illumination unit 31, and the imaging camera 41 are arranged at positions that do not interfere with the portal frame 130 and the coating nozzle 150 even when the slider portion 123 moves in the Y direction.

  FIG. 9 is a system configuration diagram illustrating another example of a form embodying the present invention. In the coating apparatus 101 having the form described with reference to FIGS. 7 and 8, the irradiation unit 3, the light receiving unit 4, and the inspection unit. 5, each apparatus of the relative movement part 7 and the application | coating part 8 has shown a mode that each apparatus of the control part 9 is connected.

  Since the coating apparatus 101 has such a configuration, the position of the coating nozzle 150 in the Z direction with respect to the substrate 110w is set while moving the slider portion 123 in the Y direction, and a predetermined coating is performed by discharging the coating liquid. The action can be performed. Then, the slider unit 123 continues to move in the Y direction, the application operation is continued, and the gate frame 130 and the application nozzle 150 are separated from the illumination unit 31 and the imaging camera 41 until the application is completed. Then, after moving away from the position that does not affect the observation, the coating start portion on the substrate 110w is set as the inspection target region 110s, and the film thickness unevenness detection apparatus 1 is used to determine whether the coating state of the coating start portion is good or bad. Is done.

  In the coating apparatus 101, it is preferable to detect whether or not the coating start portion has a film thickness unevenness because the coating start portion tends to have a film thickness unevenness as compared with the central portion of the substrate. In addition, when the coating operation is completed or when the coating operation is completed, a notification is made as to whether the film thickness unevenness has been detected, or when the coated substrate is delivered to the downstream apparatus, the film thickness unevenness is included in the substrate. And whether or not there is information. Then, if it is a coated substrate with no film thickness unevenness, it will continue with normal processing (such as drying of the coated film), and if it is a coated substrate with uneven film thickness, it will be re-inspected without normal processing. And playback processing can be performed.

As described above, the coating apparatus equipped with the film thickness unevenness inspection apparatus according to the present invention immediately notifies the detection result to an external device when the film thickness unevenness occurs, or stops the coating operation itself. can do. Therefore, it is possible to prevent wasteful application liquid consumption and substrate loss, thereby contributing to cost reduction.

DESCRIPTION OF SYMBOLS 1 Observation apparatus 2 Substrate mounting part 3 Irradiation part 4 Light-receiving part 5 Inspection part 7 Relative movement part 8 Application | coating part 9 Control part

10 Substrate 10f Inspection target area

21 Substrate mounting table 23 Moving mechanism

Reference Signs List 31 Illumination unit 32 Housing part 33 Light emitting part 34 Partial light shielding part 37 Illumination optical axis 38 Light quantity adjustment part

41 Imaging camera 42 Lens 43a Bright part (white part of stripe pattern)
43b Dark part (black part of stripe pattern)
43c Deviation extraction pixel (overdetection condition)
43d Broken line indicating the boundary between the bright part and the dark part 43s Part with uneven thickness (vertical stripe) 43m
43p
43z shift extraction pixel (conventional condition)
44 Deviation extraction pixel group slightly scattered and scattered 45 Misalignment extraction pixel group scattered in a straight line 46 Misalignment extraction pixel group scattered in a straight line 47 Observation optical axis 48 Predetermined region

50 Setting reference value 51 Setting reference value 52 Setting reference value

DESCRIPTION OF SYMBOLS 90 Control computer 91 Information input means 92 Information output means 93 Notification means 94 Information recording means 95 Equipment control unit 96 Image processing unit

101 Coating device 110w Coating substrate (inspection object)
110f Inspection target area 110s Application start portion 112 Frame portion 115 Portal frame (inspection portion)
121 Substrate mounting table 122 Guide rail 123 Slider unit 130 Portal frame (application unit)
140 Lifting actuator 150 Coating nozzle

Claims (8)

An irradiation unit that emits light of a specific irradiation pattern toward the coating film formed on the substrate,
A light receiving unit that receives the reflected light of the specific irradiation pattern reflected by the surface of the coating film,
A film thickness provided with an inspection unit that determines the quality of the coating film formation state by comparing the light receiving pattern of the reflected light received by the light receiving unit with a reference pattern corresponding to the specific irradiation pattern An unevenness detection device,
The inspection unit
An image comparison unit for comparing the light receiving pattern and the reference pattern;
A deviation extraction image generation unit that compares the light reception pattern with the reference pattern in the image comparison unit and generates an image composed of pixels extracted as a deviation part as a deviation extraction image;
A shift extraction pixel area integration unit that integrates the areas of the pixels extracted in the shift extraction image existing in a predetermined region of the shift extraction image as a shift extraction pixel area integration value;
A film thickness unevenness detection apparatus comprising: an integrated deviation area determination unit that determines whether the deviation extraction pixel area integrated value is greater than a set reference value.
It is a film thickness nonuniformity detection apparatus of Claim 1, Comprising:
The inspection unit
A first reference value registration unit for registering a set reference value of the integrated deviation area determination unit as a first reference value;
When the deviation extraction pixel area integrated value is larger than the first reference value,
The area of the extracted pixels outside the predetermined area, which is present continuously with the extracted pixels existing in the predetermined area of the deviation extracted image, is added to the integrated value of the extracted deviation pixel area. A shift extraction pixel area additional integration unit, which is set as a shift extraction pixel area additional integration value,
A second reference value registration unit for registering a setting reference value for the shift extraction pixel area additional integrated value as a second reference value;
It is determined whether the deviation extraction pixel area additional integrated value is greater than the second reference value.
A film thickness nonuniformity detection apparatus comprising: an integrated deviation area second determination unit.
The film thickness unevenness detection apparatus according to claim 1, wherein the predetermined area is an area extending in a coating direction or a direction perpendicular thereto.
A substrate mounting portion, a coating nozzle, a moving mechanism,
A coating apparatus with a film thickness unevenness detection apparatus comprising the film thickness unevenness detection apparatus according to any one of claims 1 to 3,
A coating apparatus with a film thickness unevenness detector, wherein the reflected light reflected by the surface of the coating film is reflected light reflected by the surface of the coating film applied by the coating nozzle.




Irradiating light of a specific irradiation pattern toward the coating film formed on the substrate;
Receiving the light irradiated in the irradiation step and reflected by the surface of the coating film,
A method for detecting unevenness in film thickness, comprising: an inspection step for determining whether a coating film is formed by comparing a pattern received in the light receiving step with a reference pattern corresponding to the specific irradiation pattern. ,
The inspection step includes
An image comparison step for comparing the light receiving pattern and the reference pattern;
A shift extraction image generation step of generating an image composed of pixels extracted as a shift portion by comparing the light receiving pattern and the irradiation pattern in the image comparison step;
A shift extraction area integration step of integrating the area of the shift extracted image existing in a predetermined region of the shift extraction image as a shift extraction pixel area integration value;
An integrated film thickness non-uniformity detecting method comprising: determining whether the integrated value of the extracted pixel area is larger than a set reference value.
The film thickness unevenness detection method according to claim 5,
The inspection step includes
Read the first reference value, which is the criterion value for the integrated deviation area,
When the total value of the accumulated deviation areas is larger than the registered first reference value,
The area of the extracted pixels outside the predetermined area, which is present continuously with the extracted pixels existing in the predetermined area of the deviation extracted image, is added to the integrated value of the extracted deviation pixel area. A shift extraction pixel area additional integration step, which is set as a shift extraction pixel area additional integration value,
Read a second reference value that is a determination reference value for the deviation extraction pixel area additional integrated value,
It is determined whether the deviation extraction pixel area additional integrated value is greater than the second reference value.
A film thickness nonuniformity detection method comprising: an integrated deviation area second determination step.
The film thickness unevenness detection method according to claim 1, wherein the predetermined region is a region extending in a coating direction or a direction perpendicular thereto.

Placing the substrate on the substrate platform;
A step of relatively moving the substrate mounting portion and the coating nozzle;
Forming a coating film on the substrate by discharging a coating liquid from a coating nozzle while performing the relative movement; and
Detecting uneven thickness of the coating film formed on the substrate in the coating step,
The film thickness unevenness detection method according to any one of claims 5 to 7, wherein the film thickness unevenness detection step is a film thickness unevenness detection method according to any one of claims 5 to 7.

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