JP2021124298A - Device and method for inspecting substrate - Google Patents

Abstract

To provide an inspection device for a substrate that can detect recesses or protrusions of the surface of the substrate or can detect unevenness of color on the surface of the substrate.SOLUTION: The inspection device for a substrate includes: a substrate stage on which a substrate is to be set; a first display, of which image display surface serves as a light source for light to be emitted to a first surface side of the substrate set on the substrate stage; first control means for controlling an image to be displayed in the image display surface of the first display; imaging means for taking an image of a first surface side of the substrate; and image processing means for processing the image taken by the imaging means.SELECTED DRAWING: Figure 1

Description

The present invention relates to a substrate inspection device and a substrate inspection method.

Various substrates are used for manufacturing semiconductor devices and the like. In order to improve the yield of semiconductor devices and the like, various studies have been conventionally conducted on substrate inspection devices and inspection methods capable of inspecting substrates before they are used in the manufacturing process of semiconductor devices and the like.

For example, Patent Document 1 describes a light irradiation unit that irradiates light on the surface to be inspected of a substrate, an imaging unit that acquires an image of the light irradiation unit reflected on the surface to be inspected, and the substrate or the light irradiation unit. By controlling the position of, the moving portion that moves the image of the light-irradiated portion reflected on the surface to be inspected and the light emitted from the light-irradiated portion are scattered at the defective portion of the surface to be inspected. A substrate inspection device including an inspection unit that inspects the surface to be inspected by detecting an image that is formed outside the contour line of the image of the light irradiation unit is disclosed. Has been done.

Japanese Unexamined Patent Publication No. 2016-020824

By the way, in recent years, a substrate that can detect color unevenness on the substrate surface caused by irregularities on the substrate surface, non-uniform composition of the surface of the substrate after a reaction process such as heat treatment, and non-uniform thickness. Inspection equipment was required.

Therefore, in view of the problems of the prior art, one aspect of the present invention is to provide a substrate inspection apparatus capable of detecting unevenness and color unevenness on the substrate surface.

According to one aspect of the present invention in order to solve the above problems.
The board stage on which the board is installed and
A first display provided with a first image display surface which is a light source of light irradiating the first surface side of the substrate installed on the substrate stage.
A first control means for controlling an image displayed on the first image display surface of the first display, and
An imaging means for imaging the first surface side of the substrate, and
Provided is an image processing means for processing an image obtained by the imaging means, and a substrate inspection apparatus including the image processing means.

According to one aspect of the present invention, it is possible to provide a substrate inspection device capable of detecting unevenness and color unevenness on the substrate surface.

Sectional drawing of the inspection apparatus which concerns on embodiment of this invention. Explanatory drawing of the image to be displayed on the 1st image display surface of the 1st display. Explanatory drawing of the imaging area. Explanatory drawing of the transparent area. FIG. 5 is a cross-sectional view of a modified example of the inspection device according to the embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments and can be applied to the following embodiments without departing from the scope of the present invention. Various modifications and substitutions can be made.
[Board inspection device]
The inventors of the present invention have diligently studied a substrate inspection device capable of detecting color unevenness caused by unevenness of the substrate surface, non-uniform composition of the substrate surface, and the like. During the study, when the surface of the substrate is irradiated with linear light, the substrate is located near the boundary between the bright region that reflects the linear light and the dark region adjacent to the bright region on the surface of the substrate. We focused on increasing the contrast of surface irregularities. Then, the operation of imaging the vicinity of the boundary between the bright region and the dark region on the substrate surface is repeatedly performed while changing the position of the bright region, and the obtained images are stitched together to form unevenness on the substrate surface. It was found that an image that clarifies the above can be obtained.

Further, when the surface side of the substrate is irradiated with linear light, the substrate is observed by observing a region of one surface of the substrate other than the bright region where the linear light is reflected, that is, the light is directly irradiated. We focused on the fact that uneven color on the surface, that is, regions with different colors can be easily detected. Then, the operation of imaging a region other than the bright region on the substrate surface is repeatedly performed while changing the position of the bright region, and the obtained images are stitched together to clarify the color unevenness of the substrate surface. It was found that the image was obtained.

Based on the above findings, the substrate inspection device of this embodiment was completed.

FIG. 1 shows a cross-sectional view of the substrate inspection device 10 according to the present embodiment in a plane passing through the center of the substrate 12.

The substrate inspection device 10 of the present embodiment can include a substrate stage 11 on which the substrate is installed, a first display 13, a first control means 14, an imaging means 15, and an image processing means 16.
The first display 13 is a light source of light that irradiates the first surface 12A side of the substrate 12 installed on the substrate stage 11.
The first control means 14 can control the image displayed on the first display 13.

The imaging means 15 can image the first surface 12A side of the substrate 12 arranged on the substrate stage 11.
The image processing means 16 can process the image obtained by the imaging means 15.

(1) Each member of the substrate inspection device of the present embodiment Each member of the substrate inspection device 10 of the present embodiment will be described below.
(Stage for board)
The substrate stage 11 may be any stage as long as it can be installed with a substrate to be inspected, and its configuration is not particularly limited.

The substrate stage 11 may be provided with, for example, a means for correcting the inclination of the substrate 12 installed on the substrate stage 11 to make it horizontal, for example, an inclination correction means described later.

The type of substrate to be inspected by the substrate inspection device of the present embodiment is not particularly limited, and various substrates can be used. Further, the shape of the substrate is not particularly limited, but for example, a disk-shaped substrate can be used.
(1st display)
The first display 13 serves as a light source for light that the first image display surface 13A irradiates on the first surface 12A side of the substrate 12.

As described above, according to the study of the inventor of the present invention, when the surface of the substrate is irradiated with linear light, a bright region that reflects the linear light is formed on the surface of the substrate. By imaging a predetermined region while changing the position of the bright region and joining the regions, an image in which the unevenness of the substrate surface and the color unevenness are clarified can be obtained.

According to a further study by the inventor of the present invention, for example, in the first luminance region which is a high-luminance region where the linear brightness is high on the image display surface of the display and in the low-luminance region where the luminance is lower than the first luminance region. By displaying an image including a certain second luminance region and projecting it on the surface of the substrate, the above-mentioned bright region can be formed on the surface of the substrate corresponding to the first luminance region. That is, the above-mentioned bright region can be formed on the surface of the substrate by using a display as a light source instead of a lighting fixture such as a fluorescent lamp or LED lighting.

Then, since the display can change the image on the image display surface by a control means such as a personal computer, for example, the position of the first brightness region, which is the high brightness region described above, is moved within the image display surface. As a result, the position of the bright region on the surface of the substrate can be moved. Therefore, according to the substrate inspection device of the present embodiment, the light source and the imaging means are moved by using the first display 13 as a light source for irradiating the first surface 12A side of the substrate 12. Instead, the position of the bright region described above can be changed only by changing the displayed image.

The first display 13 is not particularly limited as long as it is a display device capable of displaying a predetermined image and irradiating the first surface 12A of the substrate 12 with light. For example, one or more types selected from a liquid crystal display, a plasma display (PDP), an organic EL (electroluminescence) display, an inorganic EL display, a cathode ray tube display (CRT), an LED display, a projector and the like can be mentioned.

The first display 13 may be fixed to, for example, a housing (not shown) of the substrate inspection device 10. However, the present invention is not limited to this, and the first display 13 can be fixed by using a tripod or the like separately from other members.
(First control means)
The first control means 14 can control the image to be displayed on the first image display surface 13A of the first display 13.

As described above, the first control means 14 provides the first image display surface 13A of the first display 13 with, for example, a linear first luminance region and a second luminance region having a lower luminance than the first luminance region. It can be controlled to display the including image. For example, it is possible to control the display of an image including the linear white first luminance region in the black second luminance region. The color of each area here is an example, and can be arbitrarily selected according to the color of the substrate to be projected and the like.

The specific shape of the first luminance region is not particularly limited, and for example, the bright region on the first surface 12A of the substrate 12 may be configured to have a linear shape, and the specific shape may be. There is no particular limitation. The first luminance region included in the image displayed on the first image display surface of the first display preferably has a linear shape, and is selected from a linear shape, a linear shape including a bent portion, a wavy line shape, and the like. Can be any of the above. The shape of the linear bent portion including the bent portion is not particularly limited, and may be, for example, an arc shape, an L-shape bent at a predetermined angle (a dogleg shape), or the like. The number of linearly shaped bent portions including the bent portions is not particularly limited, and one or more bent portions may be provided. When the linear first luminance region including the bent portion has a plurality of bent portions, the shape of the bent portion may be the same, but the bent portions may have different shapes. Further, the wavy line shape is a linear shape in which the bent portions are arranged while alternately changing the directions at predetermined intervals so as to be a wavy line. The shape of the first luminance region is particularly preferably a linear shape.

Since the first luminance region having a linear shape is a region having a certain thickness, it can be rephrased as a region having a strip shape. For example, in the case of a high-luminance region having a linear shape, it is a substantially square region.

The length of the first luminance region in the longitudinal direction is not particularly limited, but from the viewpoint of efficient inspection, for example, light is irradiated over the entire width direction of the substrate to be inspected so that a bright region can be formed. You can choose the length.

In the substrate inspection device of the present embodiment, when inspecting the unevenness of the substrate surface, as will be described later, in the substrate surface, a dark region along the longitudinal direction of the bright region and adjacent to the bright region and the bright region. The first imaging region including the above can be imaged by the imaging means 15. Then, while changing the position of the bright region, the first imaging region is photographed, and the image of the portion to be inspected when the obtained images of the first imaging region are joined, for example, the image of the entire substrate surface is obtained. It is preferable to carry out repeatedly until it is obtained.

Further, in the substrate inspection apparatus of the present embodiment, when inspecting color unevenness on the substrate surface, the imaging means 15 captures a second imaging region along the longitudinal direction of the bright region and a region other than the bright region. can. Then, while changing the position of the bright region, the second imaging region is photographed, and the image of the portion to be inspected when the obtained images of the second imaging region are joined, for example, the image of the entire substrate surface is obtained. It is preferable to carry out repeatedly until it is obtained.

Therefore, from the viewpoint of improving the efficiency of inspection by increasing the number of imaging regions that can be simultaneously imaged and reducing the number of imagings, the first control means 14 forms a plurality of bright regions on the first surface of the substrate 12. It is preferable to select an image to be displayed on the first image display surface 13A of the first display 13 so that the image can be displayed. For example, as shown in FIG. 2, the first control means 14 has a plurality of linear first luminance regions 21 parallel to each other on the first image display surface 13A of the first display 13, and more than the first luminance region 21. It is preferable to display an image including the second brightness region 22 having low brightness. In this case, as shown in FIG. 2, the first luminance region 21 and the second luminance region 22 can be formed alternately. Then, in the first image display surface 13A, the plurality of first luminance regions 21 can be moved in the direction of arrow A, which is a direction perpendicular to the longitudinal direction of the first luminance region, or in the direction opposite to that of arrow A. preferable.
In this case, it is preferable to adjust the size of the second luminance region 22 and the like so that a dark region is formed between the plurality of bright regions formed on the first surface of the substrate 12. When displaying a plurality of linear first luminance regions 21 parallel to each other as described above, the plurality of first luminance regions 21 may have the same shape or different shapes. However, since the inspection can be easily performed, the plurality of first luminance regions 21 and the plurality of bright regions formed on the first surface of the substrate corresponding to the first luminance region 21 have the same shape. Is preferable.

The first control means 14 is not particularly limited as long as it is a means capable of controlling an image displayed on the first image display surface 13A of the first display 13. The first control means 14 may include, for example, an image reproduction device such as an optical disk player, a hard disk player, or a video tape player, a personal computer, or the like.
(Imaging means)
The imaging means 15 can image the first surface 12A side of the substrate 12 arranged on the substrate stage 11.

The specific area to be imaged by the imaging means 15 is not particularly limited, and the area to be imaged can be selected depending on the object to be inspected. Specifically, a predetermined range can be imaged according to the case of inspecting the unevenness of the substrate surface and the case of inspecting the color unevenness. According to the substrate inspection apparatus of the present embodiment, both the unevenness of the surface of the substrate and the color unevenness can be inspected at the same time. Therefore, the first imaging region and the second imaging region described below can be imaged at the same time. In the following description, the first imaging region and the second imaging region may be collectively referred to as an imaging region.
(A) When inspecting the unevenness of the first surface of the substrate According to the study of the inventor of the present invention, light is reflected from the linear first luminance region of the first image display surface 13A of the first display 13. In the vicinity of the boundary between the bright region and the dark region adjacent to the bright region, the contrast of the unevenness of the first surface of the substrate is increased. Therefore, when inspecting the unevenness of the first surface of the substrate, the position of the first luminance region in the image displayed on the first image display surface 13A of the first display 13 is moved, so that the first of the substrate 12 is inspected. The position of the bright region formed on the surface 12A of the above can be displaced, and the imaging means 15 can image the vicinity of the boundary between the bright region and the dark region adjacent to the bright region.

Specifically, when inspecting the unevenness of the first surface of the substrate as described above, the imaging means 15 includes the first surface 12A of the substrate 12 along the longitudinal direction of the bright region and the bright region. The first imaging region including the dark region adjacent to the bright region can be imaged.

Here, the first imaging region to be imaged by the imaging means 15 will be described with reference to FIG.

FIG. 3 shows the first surface 12A of the substrate 12, and shows a state in which one linear light is irradiated and a bright region 31A that reflects the linear light is formed.

In this way, the first image display surface 13A of the first display 13 irradiates the first surface 12A of the substrate 12 with linear light corresponding to the first luminance region, so that the first surface 12A of the substrate 12 is irradiated. A bright region 31A that reflects linear light is formed on the surface 12A. The bright region 31A is a linear (band-shaped) region corresponding to the linear first luminance region displayed on the first image display surface 13A of the first display 13 as described above.

Then, the regions other than the bright region 31A are irradiated with light from the second luminance region whose brightness is lower than that of the first luminance region in the image displayed on the first image display surface 13A of the first display 13, and the bright region 31A It becomes a dark dark region 31B as compared with.

In this case, the imaging means 15 includes a bright region 31A and a dark region 31B adjacent to the bright region 31A at least along the longitudinal direction of the bright region 31A, that is, along the X-axis direction in the drawing. It is possible to image one or more regions selected from the first imaging regions 32A and 32B surrounded by. In this case, at least the region including the first imaging region may be photographed, and the periphery of the first imaging region may also be imaged. When the area around the first imaging region is also imaged, the image of the target imaging region can be cut out from the captured image by the image processing means described later.

In the first imaging region 32A, which is the upper region of the bright region 31A, and the first imaging region 32B, which is the lower region of the bright region 31A, the arrangement of the bright region and the dark region included in each imaging region is reversed. ing. Therefore, the black and white (brightness) of the obtained image is reversed between the case where the images in the first imaging region 32A are stitched together and the case where the images in the first imaging region 32B are stitched together. Therefore, it is also possible to select the first imaging region to be imaged according to the image to be acquired.

The ratio of the area between the bright region and the dark region included in each first imaging region is not particularly limited, and when the images in the first imaging region are joined by the image processing means, the contrast of the unevenness on the substrate surface is high. As such, it can be selected according to the type of substrate and the like. For example, the position of the first imaging region can be set so that the area of the included bright region and the area of the dark region are equal to each other.

When the captured images are collected three-dimensionally and handled as image volume data as described later, the imaging means may image the entire surface of the substrate including the first imaging region.
(B) When Inspecting Color Unevenness on the Substrate Surface According to the study of the inventor of the present invention, among the first surface 12A of the substrate 12, the linear shape of the first image display surface 13A of the first display 13. By observing a region other than the bright region that reflects light from the first luminance region of the substrate, color unevenness on the first surface of the substrate, that is, regions having different colors can be easily detected. Therefore, when inspecting the color unevenness of the first surface of the substrate, the position of the first luminance region in the image displayed on the first image display surface 13A of the first display 13 is moved to move the position of the first luminance region of the substrate 12. The position of the bright region formed on the surface 12A of the light region is displaced, and the imaging means 15 can image a second imaging region that is a region other than the bright region along the longitudinal direction of the bright region.

Here, the second imaging region 33 will be described with reference to FIG.

As described above, of the first surface 12A of the substrate 12 shown in FIG. 3, the dark region 31B other than the bright region 31A is a dark region as compared with the bright region 31A. The imaging means 15 is a second imaging region 33 surrounded by a dotted line other than the bright region 31A, that is, in the dark region 31B, at least along the longitudinal direction of the bright region 31A, that is, along the X-axis direction in the drawing. Can be imaged. In this case, at least the region including the second imaging region 33 may be photographed, and the periphery of the second imaging region 33 may also be imaged. When the area around the second imaging region 33 is also imaged, the image of the target second imaging region can be cut out from the captured image by the image processing means described later.

Here, a case where the light in the first luminance region in the image formed on the first image display surface 13A of the first display 13 is directly applied to the first surface 12A of the substrate 12 has been described as an example. However, when inspecting color unevenness, it is not necessary that the light from the first luminance region directly irradiates the first surface 12A of the substrate 12. For example, the light emitted from the first luminance region may be irradiated to a place other than the first surface 12A of the substrate 12 and illuminated by the reflected indirect light.

However, in order to detect color unevenness, the degree of brightness in the second imaging region 33 due to the light from the first luminance region in the image displayed on the first image display surface 13A of the first display 13 is uniform. Is preferable. Therefore, as described above, the substrate 12 is irradiated with light from the first luminance region in the image displayed on the first image display surface 13A of the first display 13 at or near the first surface 12A of the substrate 12. It is preferable to form a bright region on the first surface 12A of the above, set a second imaging region along the longitudinal direction of the bright region, and perform imaging. In addition, the second imaging region has a uniform degree of brightness in the second imaging region due to the light from the first luminance region in the image displayed on the first image display surface 13A of the first display 13. It is preferable to set the area so that the length in the direction perpendicular to the longitudinal direction does not become excessively long. The length in the direction perpendicular to the longitudinal direction of the second imaging region referred to here means the length in the Y-axis direction in FIG.

As will be described later, it is also possible to form an image of the entire surface of the substrate by stitching together the images of the second imaging region captured by the image processing means. Then, from the viewpoint of more accurately detecting color unevenness from the image of the entire surface of the formed substrate, it is preferable that the brightness of the image of the entire surface of the formed substrate is uniform. That is, it is preferable that the brightness of the images in the plurality of second imaging regions constituting the image of the entire surface of the substrate is uniform. Therefore, when changing the position of the bright region 31A, it is preferable to keep the distance between the bright region 31A and the second imaging region 33 constant.

When the captured images are collected three-dimensionally and handled as image volume data as described later, the imaging means 15 covers the entire first surface 12A of the substrate 12 including the first imaging region and the second imaging region. You may take an image.

The imaging means 15 is not particularly limited as long as it can image the first imaging region and the second imaging region as described above. As the image pickup means 15, a camera module including various image pickup elements can be used. As the image pickup element, for example, one or more types selected from semiconductor image pickup elements such as CMOS (Complementary metal accessory semiconductor) sensors, CCD (Chage Coupled Device) sensors, phototubes, image pickup tubes, and the like can be used.

The image captured by the imaging means 15 may be a moving image or a still image. In the case of moving images, for example, a plurality of still images in the imaging region at an arbitrary timing can be extracted and stitched together by an image processing means described later.

Further, the imaging means 15 may be a line scan camera, for example, because it is sufficient if the imaging means 15 can image a linear (band-shaped) imaging region depending on the shape of the bright region or the like. The line scan camera means a camera module in which image pickup elements are arranged in a straight line and can image a linear (band-shaped) image pickup region.

The imaging means 15 may be fixed to, for example, a housing (not shown) of the substrate inspection device 10. However, the present invention is not limited to this, and the imaging means 15 can be fixed by using a tripod or the like separately from other members.
(Image processing means)
The image processing means 16 can process the image captured by the imaging means 15.

The image processing means 16 is an ASIC (application specific integrated circuit) or the like, and is in charge of processing an image captured by the imaging means 15.

The image processing means 16 cuts out, for example, a strip-shaped image corresponding to the first imaging region or the second imaging region described above according to the inspection target from the image captured by the imaging means 15, and moves the bright region. By arranging and joining them together, an image of the entire surface of the substrate can be formed. At this time, it is also possible to correct the contrast in the image or perform image processing such as binarization processing as necessary.

When the moving image is captured by the imaging means 15, the image processing means 16 can also extract a plurality of still images in the imaging region at a predetermined timing.

Then, the image created by the image processing means 16 can be output to the output means 17, and the unevenness of the substrate surface and the color unevenness can be visually detected from the obtained image due to the difference in contrast in the obtained image. .. It should be noted that the unevenness of the first surface of the substrate can be detected from the image obtained by connecting the first imaging regions described above, and the color unevenness of the first surface of the substrate can be detected from the image obtained by connecting the second imaging regions.

The configuration of the output means 17 is not particularly limited, and can be, for example, a display means such as various displays or a printing means such as a printer.

The image processing means 16 can be provided with, for example, an AI (artificial intelligence), and can detect irregularities and color unevenness on the first surface of the substrate from the image of the substrate surface obtained as described above. It can also be configured to notify you. In addition, the image processing means or the like may be configured so that, for example, a preset threshold value such as chromaticity or lightness can be used to detect and notify unevenness or a portion where color unevenness occurs in the formed image. can.

The image processing means 16 can be realized by software in one ASIC, but a part or all of it may be realized by hardware, for example, by providing a plurality of ASICs.

Further, the image processing means 16 can also three-dimensionally collect the images captured by the image pickup means 15 and handle them as image volume data. Then, the image processing means 16 can perform volume rendering processing on the image volume data on the surface of the substrate obtained by the imaging means 15. Specifically, for example, the image processing means 16 creates (renders) an isosurface image at the brightness value of the first imaging region or the second imaging region for the image volume data, thereby covering the entire surface of the substrate. , Images in the first imaging region and the second imaging region can be extracted. In this case, even if the first display, which is a light source, is slanted at the time of imaging, or the position of the light source is deviated for each photograph, the region of the predetermined luminance value is common, so that the predetermined luminance value is used. By dividing by, the target first imaging region or second imaging region can be taken out regardless of the number of photographs, and unevenness and color unevenness can be detected more easily.

By treating the obtained image of the substrate surface as image volume data in the image processing means 16, the brightness and the like are set according to the size of unevenness and color unevenness to be detected, and the image volume data of the substrate surface is divided. , The isosurface can be extracted.
(2) Other Arbitrary Members That the Substrate Inspection Device of the Present Embodiment Can Have The Substrate Inspection Device of the present embodiment may further have an arbitrary member in addition to the above-mentioned members.
(Inclination correction means)
The substrate inspection device of the present embodiment may further include, for example, an inclination correction means for leveling the substrate. The tilt correction means is provided, for example, on the stage for the substrate described above or the frame of the substrate inspection device of the present embodiment, and the inclination is corrected so that the surface of the substrate to be inspected is horizontal with respect to the light source. It can be configured as follows.
(Second display, second control means, light source control means)
Further, up to this point, an example in which the first display 13 as a light source is provided only on the first surface 12A side of the substrate 12, but the present invention is not limited to this. The substrate inspection device 10 of the present embodiment includes, for example, a second image display surface 18A which is a light source for irradiating the second surface 12B side located on the opposite side of the first surface 12A of the substrate 12. A second display 18 and a second control means 19 for controlling an image to be displayed on the second image display surface of the second display may be further provided.
Color unevenness on the surface of the substrate is caused by, for example, uneven composition of the surface of the substrate, non-uniform thickness, and the like. Then, for example, if a recess or the like is formed on the second surface which is the back surface of the substrate and there is a portion where the thickness of the substrate is not uniform, it may be detected as color unevenness on the first surface side. For this reason, it is more preferable to detect the unevenness of the back surface of the substrate as well, so that it can be confirmed whether the cause is, for example, a recess on the back surface side of the substrate.

Therefore, the inventor of the present invention has made a diligent study. During the study, when the second surface of the substrate was irradiated with linear light, the second surface of the first surface located on the opposite side of the second surface of the substrate was irradiated. Attention was paid to the fact that the contrast between the unevenness of the first surface and the second surface of the substrate is increased in the transmission region through which linear light is transmitted. Then, the operation of imaging (photographing) the transmission region on the first surface of the substrate is repeatedly performed while changing the position of the transmission region, and the obtained images are stitched together to form the first substrate. It has been found that an image in which the unevenness of the surface and the second surface of the above surface is clarified can be obtained.

Hereinafter, each member when the second display 18 and the like are provided on the second surface 12B side of the substrate 12 will be described.
(A) Second Display The second display 18 serves as a light source for light emitted by the second image display surface 18A on the second surface 12B side of the substrate 12.

As described above, according to the study of the inventor of the present invention, when the second surface of the substrate is irradiated with linear light, the first surface of the substrate is irradiated with the line of the second surface. A transmission region that transmits light is formed. By imaging the transmission region and joining the transmission regions while changing the position of the transmission region, an image in which the irregularities of the first surface and the second surface of the substrate are clarified can be obtained.

According to a further study by the inventor of the present invention, for example, in the first luminance region which is a high-luminance region where the linear brightness is high on the image display surface of the display and in the low-luminance region where the luminance is lower than the first luminance region. By displaying an image including a certain second luminance region and projecting it on the second surface of the substrate, the transmission region described above can be formed on the first surface of the substrate corresponding to the high luminance region. That is, the transmission region described above can be formed on the surface of the substrate by using a display as a light source instead of a lighting fixture such as a fluorescent lamp or LED lighting.

Since the display can change the image on the image display surface by a control means such as a personal computer, for example, by moving the position of the high-luminance region described above in the image display surface, the substrate can be changed. The position of the transmission region on the surface of 1 can be moved. Therefore, according to the substrate inspection device of the present embodiment, the light source and the imaging means are moved by using the second display 18 as a light source for irradiating the second surface 12B side of the substrate 12. Instead, the position of the bright region described above can be changed only by changing the displayed image.

The second display 18 is not particularly limited as long as it is a display device capable of displaying a predetermined image and irradiating the second surface 12B of the substrate 12 with light. For example, one or more types selected from a liquid crystal display, a plasma display (PDP), an organic EL (electroluminescence) display, an inorganic EL display, a cathode ray tube display (CRT), an LED display, a projector and the like can be mentioned.

The second display 18 can be fixed to, for example, a housing (not shown) of the substrate inspection device 10. However, the present invention is not limited to this, and the first display 13 can be fixed by using a tripod or the like separately from other members.
(B) Second Control Means The second control means 19 can control the image to be displayed on the second image display surface 18A of the second display 18.

As described above, the second control means 19 provides the second image display surface 18A of the second display 18 with, for example, a linear first luminance region and a second luminance region having a lower luminance than the first luminance region. It can be controlled to display the including image. For example, it is possible to control the display of an image including the linear white first luminance region in the black second luminance region. The color of each area here is an example, and can be arbitrarily selected according to the color of the substrate to be projected and the like.

The specific shape of the first luminance region is not particularly limited, and for example, the transmission region on the first surface 12A of the substrate 12 may be configured to have a linear shape, and the specific shape may be. There is no particular limitation. The first luminance region included in the image displayed on the second image display surface of the second display preferably has a linear shape, and is selected from a linear shape, a linear shape including a bent portion, a wavy line shape, and the like. Can be any of the above. The shape of the linear bent portion including the bent portion is not particularly limited, and may be, for example, an arc shape, an L-shape bent at a predetermined angle (a dogleg shape), or the like. The number of linearly shaped bent portions including the bent portions is not particularly limited, and one or more bent portions may be provided. When the linear first luminance region including the bent portion has a plurality of bent portions, the shape of the bent portion may be the same, but the bent portions may have different shapes. Further, the wavy line shape is a linear shape in which the bent portions are arranged while alternately changing the directions at predetermined intervals so as to be a wavy line. The shape of the second luminance region is particularly preferably a linear shape.

Since the second luminance region having a linear shape is a region having a certain thickness, it can be rephrased as a region having a strip shape. For example, in the case of a high-luminance region having a linear shape, it is a substantially square region.

The length of the second luminance region in the longitudinal direction is not particularly limited, but from the viewpoint of efficient inspection, for example, light is irradiated over the entire width direction of the substrate to be inspected so that a transmission region can be formed. You can choose the length.

In the substrate inspection device of the present embodiment, the transmission region of the substrate surface can be imaged by the imaging means 15. Then, while changing the position of the transparent region, photographing the transparent region is repeated until an image of a portion to be inspected when the obtained images of the transparent region are joined, for example, an image of the entire surface of the substrate is obtained. It is preferable to carry out.

Therefore, from the viewpoint of improving the efficiency of inspection by increasing the number of transmission regions that can be imaged at the same time and reducing the number of imaging times, the second control means 19 forms a plurality of transmission regions on the first surface of the substrate 12. It is preferable to select an image to be displayed on the second image display surface 18A of the second display 18 so as to be possible. For example, the second control means 19 has a plurality of linear first luminance regions parallel to each other and a second luminance region having a lower luminance than the first luminance region on the second image display surface 18A of the second display 18. It is preferable to display an image containing. In this case, the first luminance region and the second luminance region can be formed alternately. Then, it is preferable to move the plurality of first luminance regions in the direction perpendicular to the longitudinal direction of the first luminance region.

In this case, it is preferable to adjust the size of the second luminance region and the like so that a dark region is formed between the plurality of transmission regions formed on the first surface 12A of the substrate 12. When displaying a plurality of linear first luminance regions parallel to each other as described above, the plurality of first luminance regions may have the same shape or different shapes. However, since the inspection can be easily performed, it is preferable that the plurality of first luminance regions and the plurality of transmission regions formed on the first surface of the substrate corresponding to the first luminance region have the same shape. ..

The second control means 19 is not particularly limited as long as it is a means capable of controlling the image displayed on the second image display surface 18A of the second display 18. The second control means 19 may include, for example, an image reproduction device such as an optical disk player, a hard disk player, or a video tape player, a personal computer, or the like.

The second display and the second control means may have the same configuration as the first display and the first control means described above, or may have different configurations.
(C) Light Source Control Means When the surface of the substrate is simultaneously irradiated with light from the first display 13 and the second display 18, the light from the first image display surface 13A of the first display 13 and the second display 18 Light from the second image display surface 18A may enter the imaging means 15 at the same time, and the above-mentioned first imaging region, second imaging region, and transmission region may not be imaged to the extent that color unevenness or unevenness can be detected. ..

Therefore, when the second display 18 is provided on the second surface 12B side of the substrate 12, the substrate inspection device 10 of the present embodiment further includes a light source control means 181 for controlling the first display 13 and the second display 18. Is preferable. The control method of the light source control means 181 is not particularly limited, but it is preferable that the first display 13 and the second display 18 are turned on alternately, for example. Then, while the first display 13 is lit, the second display 18 is turned off, and the imaging means 15 images the first imaging region and the second imaging region of the first surface 12A of the substrate 12. be able to. While the second display 18 is lit, the first display 13 is turned off, and the imaging means 15 can image the transmission region of the first surface 12A of the substrate 12.

Then, for example, the image processing means 16 described above cuts out, for example, a strip-shaped image corresponding to the transmission region from the image captured by the imaging means 15 in addition to the operation described above, and moves the transmission region. By arranging them along the direction and joining them together, an image of the entire first surface of the substrate can be formed. At this time, the contrast in each image can be corrected as needed.

When the moving image is captured by the imaging means 15, the image processing means 16 can also extract a plurality of still images in the transmission region at a predetermined timing.

Here, a configuration example in which the image captured by the imaging means 15 is processed by the image processing means 16 described above has been described, but the present invention is not limited to this, and for example, in addition to the image processing means 16, one or two or more are further described. The image processing means and the like may be provided, and the image captured by a plurality of image processing means may be processed.

Further, for example, an image obtained by connecting the first imaging region and the second imaging region described above and an image obtained by connecting the transmission regions are superimposed to cause color unevenness, and the first surface and the second surface of the substrate. It can also be configured so that the position with the unevenness can be compared and confirmed.

The image processing means 16 can also three-dimensionally collect the images captured by the image pickup means 15 and handle them as image volume data. Then, the image processing means 16 can perform volume rendering processing on the image volume data on the surface of the substrate obtained by the imaging means 15. Specifically, for example, the image processing means 16 creates (renders) an isosurface image with the brightness value of the transmission region for the image volume data, thereby extracting the image of the transmission region over the entire surface of the substrate. be able to. In this case, even if the second display is slanted when taking an image or the position of the light source is deviated for each photograph, the area of the predetermined brightness value is common, so the area is divided by the predetermined brightness value. This makes it possible to extract the target transparent region and detect unevenness more easily regardless of the number of photographs.

By treating the obtained image of the substrate surface as image volume data in the image processing means 16, the brightness and the like are set according to the size of the unevenness to be detected, the image volume data of the substrate surface is divided, and the isosurfaces are obtained. A surface (isosurface) can be taken out.

By detecting the unevenness of the substrate surface using the transmitted light in this way, the unevenness of the first surface and the second surface of the substrate can be detected together. Therefore, it is possible to efficiently inspect the unevenness of the substrate surface on both sides of the substrate.
(D) About the imaging means when the second display and the second control means are provided As the imaging means, the above-mentioned imaging means 15 can be used, and the first imaging means is used to image the transmission region. In addition to the above-described imaging means 15, a second imaging means may be provided.

Here, a transmission region to be imaged by the imaging means 15 will be described with reference to FIG.

FIG. 4 shows the first surface 12A side of the substrate 12, and the side opposite to the first surface 12A of the substrate 12, that is, the back surface is the second surface.

Then, FIG. 4 shows a state in which the second surface 12B is irradiated with one linear light, and the transmission region 41A corresponding to this is formed on the first surface 12A.

When the second surface 12B of the substrate 12 is irradiated with linear light, a transmission region 41A is formed on the first surface 12A of the substrate 12. The transmission region 41A is a linear (band-shaped) region corresponding to the linear light of the first luminance region in the image displayed on the second image display surface 18A of the second display 18 which is a light source.

The region other than the transmission region 41A is a dark region that is darker than the transmission region 41A because the degree of light transmission from the light source is low or is not transmitted, and is on the first surface 12A of the substrate 12. A dark region 41B is formed in the area.

In this case, the imaging means can image the transmission region 41A. However, the imaging means may image the region including the transmission region 41A, and the periphery of the transmission region 41A can also be imaged. For example, along the longitudinal direction of the transmission region 41A, that is, along the X-axis direction in the drawing, the third imaging region 42 surrounded by the dotted line including the transmission region 41A can be imaged. When the transmission region 41A is imaged, when the surrounding region is also imaged, the image of the target transmission region can be cut out from the captured image by the image processing means described above.

The image captured by the imaging means 15 may be a moving image or a still image. In the case of moving images, for example, a plurality of still images in a transmission region at an arbitrary timing can be extracted and used from the captured images by an image processing means.
(Half mirror)
The substrate inspection device of the present embodiment may further include a half mirror on the optical path of light irradiating from the first display to the first surface side of the substrate.

Specifically, like the substrate inspection device 50 shown in FIG. 5, the half mirror 51 can be provided on the optical path L of the light irradiating from the first display 13 to the first surface 12A side of the substrate 12. ..

When the substrate inspection device 50 of the present embodiment includes the half mirror 51, the degree of freedom in arranging the first display 13 and the imaging means 15 in the substrate inspection device 50 can be increased, and the device can be made compact. ..

In the substrate inspection device 50 shown in FIG. 5, the half mirror 51 can reflect the light from the first display 13 and irradiate the first surface 12A of the substrate 12 along the optical path L.

Since the half mirror 51 transmits the reflected light from the first surface 12A of the substrate 12, for example, an imaging means 15 is provided above the first surface of the substrate 12 in the vertical direction, and the first surface of the substrate 12 is provided. 12A can be imaged.

When the substrate inspection device of the present embodiment has a half mirror, the number of the half mirrors is not particularly limited, and any number can be provided depending on the arrangement of the first display 13 and the like, the shape of the target optical path, and the like. Further, the substrate inspection device of the present embodiment may have an arbitrary member for adjusting the optical path, such as a mirror other than a half mirror and a lens.

Since the substrate inspection device 50 shown in FIG. 5 can have the same configuration as the substrate inspection device 10 described with reference to FIG. 1 except that the half mirror 51 is provided, the description thereof is omitted here. do.

According to the substrate inspection apparatus of the present embodiment described above, unevenness on the substrate surface and color unevenness on the substrate surface can be easily detected by a simple apparatus configuration including a display, an imaging means, and a stage for the substrate. Becomes possible.

Further, in the substrate inspection device of the present embodiment, since the image display surface of the display is used as the light source, the substrate can be moved by moving the position of the first luminance region in the image to be displayed on the image display surface of the display. The position of the bright region and the transparent region formed in the image can be moved.

Therefore, according to the substrate inspection device of the present embodiment, it is not necessary to move the light source or the imaging means, so that the substrate inspection device can be made compact.
[Board inspection method]
The substrate inspection method of the present embodiment will be described. The substrate inspection method of the present embodiment can be suitably carried out by using the substrate inspection apparatus described above. Therefore, some of the matters already explained will be omitted.

The substrate inspection method of the present embodiment can have the following steps.

A first light irradiation start step of displaying an image on the first image display surface of the first display by the first control means and irradiating the first surface side of the substrate installed on the substrate stage with light.
A first image changing step of changing an image displayed on the first image display surface of the first display by a first control means.
A first image pickup step in which the first surface side of the substrate is imaged by an image pickup means between the first light irradiation start step and the first image change step.
A first image processing step of processing an image obtained in the first imaging step.
(1) Steps of the Substrate Inspection Method of the Present Embodiment Each step of the substrate inspection method of the present embodiment will be described below.
(First light irradiation start process)
In the first light irradiation start step, the first control means can display an image on the first image display surface of the first display and irradiate the first surface side of the substrate installed on the substrate stage with light.

Since the first display, the first image display surface, the first control means, and the like have already been described, detailed description thereof will be omitted.

As an image to be displayed on the first image display surface of the first display by the first control means, for example, an image including a linear first luminance region and a second luminance region having a lower luminance than the first luminance region is included. Can be mentioned. For example, it is possible to control a table that displays an image including a linear white first luminance region in a black second luminance region. The color of each area here is an example, and can be arbitrarily selected according to the color of the substrate to be projected and the like.

Since the specific shape and the like of the first luminance region have already been described, the description thereof will be omitted here.

In particular, as described above, from the viewpoint of increasing the number of bright regions formed on the first surface of the substrate and improving the efficiency of inspection, a plurality of first control means 14 are provided on the first surface of the substrate 12. It is preferable to select an image to be displayed on the first image display surface 13A of the first display 13 so that a bright region of the above can be formed. For example, as shown in FIG. 2, in the first light irradiation start step, the first control means 14 has a plurality of linear first luminance regions 21 parallel to each other on the first image display surface 13A of the first display 13. It is preferable to display an image including a second luminance region 22 having a brightness lower than that of the first luminance region 21. As shown in FIG. 2, the first luminance region 21 and the second luminance region 22 can be formed alternately. Then, in this case, in the first image changing step described later, the first control means 14 sets the plurality of first luminance regions 21 in the direction of the arrow A, which is the direction perpendicular to the longitudinal direction of the first luminance region, or It is preferable to move it in the direction opposite to the arrow A.

In the first image changing step described later, by moving the position of the bright region on the first surface of the substrate, the first imaging region and the second imaging region to be imaged by the imaging means are moved, and the first image is captured. It is preferable that an image of a portion to be inspected when the imaging region and images captured in the second imaging region are joined, for example, an image of the entire surface of the substrate can be formed. Therefore, in the first light irradiation start step, for example, it is preferable that a bright region can be formed at or near the first end, which is an arbitrary end on the surface of the substrate. Therefore, the first control means adjusts the image and the position so that the first end portion, which is an arbitrary end portion of the first surface of the substrate, can be irradiated with the light emitted from the first luminance region. It is preferable to keep it.
(First image change process)
In the first image changing step, the image displayed on the first image display surface of the first display can be changed by the first control means. As a result, the position of the bright region can be changed on the first surface of the substrate.

The conditions for moving the position of the bright region on the first surface of the substrate in the first image changing step are not particularly limited, but as described above, the position of the bright region is moved in the first image changing step. By moving the first imaging region and the second imaging region to be imaged by the imaging means, the image of the portion to be inspected when the images captured in the first imaging region and the second imaging region are joined together. For example, it is preferable that an image of the entire surface of the substrate can be formed. Therefore, in the first image changing step, the bright region is set along the direction orthogonal to the longitudinal direction of the bright region, and the end portion opposite to the first end portion described in the first light irradiation start step. That is, it is preferable to move the straight line passing through the first end portion and the center of the substrate to the second end portion orthogonal to the end portion of the substrate because it is efficient and the surface of the substrate can be imaged without gaps.

In the first image changing step, the bright region may be moved continuously or intermittently. For example, the moving conditions in the bright region can be selected according to the performance of the imaging means and the like.

To move the bright region continuously means, for example, to move the bright region continuously without stopping. In this case, in the first imaging step described later, imaging of the first imaging region and the second imaging region can be performed at arbitrary timings and intervals.

Further, when the bright region is intermittently moved, the first image changing step and the first imaging step can be alternately performed. That is, in the first image changing step, the first imaging step is performed again after moving the bright region by a certain distance by changing the image (still image) displayed on the first image display surface of the first display. After performing one image change step, the first imaging step can be carried out.

The moving speed of the bright region or the moving distance at one time in the first image changing step is not particularly limited, and can be arbitrarily selected based on the size of unevenness and color unevenness on the substrate surface to be detected, inspection efficiency, and the like. can.

When moving the bright region in the first image changing step, for example, every time the bright region is moved by a certain amount, the first imaging step is performed to image the first imaging region and the second imaging region, and the first image described later. It can be stitched together in the processing process. Then, it is preferable to form an image of a portion to be inspected, for example, an image of the entire surface of the substrate by joining a plurality of images of a target imaging region captured in the first imaging step. Therefore, in the first image change step, after the target imaging region is imaged in the nth first imaging step, the bright region is moved until the target imaging region is imaged in the n + 1th first imaging step. It is preferable to move the bright region so that the distance to be combined and the width of the images to be stitched, that is, the width of the target imaging region match.
(First imaging step)
In the first imaging step, the first surface of the substrate can be imaged by the imaging means from the first light irradiation start step to the first image changing step. Specifically, the above-mentioned first imaging region and the second imaging region can be imaged.

In the first imaging step, at least a region including a target imaging region may be photographed, and the periphery of the target imaging region may also be imaged. When the area around the target imaging region is also imaged, the target imaging region can be cut out from the captured image in the first image processing step described later.

Since the imaging region has already been described with reference to FIG. 3, the description thereof will be omitted here.

The image captured in the first imaging step may be a moving image or a still image. In the case of moving images, for example, in the first image processing step described later, a plurality of still images in a target imaging region can be extracted and stitched together at an arbitrary timing from the captured images.

When the captured images are three-dimensionally collected and handled as image volume data in the first image processing step, the entire surface of the substrate including the imaging region may be imaged in the first imaging step.

As described above, in the first imaging step, the imaging region may be imaged, and the required image may be a linear (strip) image depending on the shape of the bright region and the like. Therefore, a line scan camera can also be used as the imaging means.
(First image processing step)
In the first image processing step, the image obtained in the first imaging step can be processed.

Specifically, for example, the image captured in the first imaging step is processed into a linear shape (strip shape) such as the first imaging regions 32A and 32B shown in FIG. 3 and the second imaging region 33, if necessary. By arranging and joining them along the moving direction of the bright region, it is possible to obtain an entire image of the substrate surface. At this time, it is also possible to correct the contrast in the image or perform image processing such as binarization processing as necessary.

When a line scan camera is used as the imaging means 15 and a linear (strip-shaped) image is acquired, the acquired images can be arranged and joined as they are without being processed.

Further, when a moving image is captured in the first imaging step, a plurality of still images in a target imaging region can be extracted at a predetermined timing in the first image processing step.

Then, for example, by outputting the image obtained in the first image processing step to the output means and visually or performing image processing, unevenness and color unevenness on the substrate surface, specifically, the first surface of the substrate can be detected. can do.

In the first image processing step, for example, AI can be used to detect and notify the unevenness and color unevenness of the substrate surface from the image of the substrate surface obtained as described above. Further, in the first image processing step, for example, it is configured to be able to detect and notify a portion where unevenness or color unevenness occurs in the formed image by a preset threshold value such as chromaticity or lightness. You can also.

The image processing in the first image processing step is not limited to the above method, and for example, the images captured in the first imaging step can be three-dimensionally collected and handled as image volume data.

Then, in the first image processing step, it is also possible to perform volume rendering processing on the image volume data of the first surface of the substrate obtained in the first imaging step. In the first image processing step, specifically, for example, by creating (rendering) an isosurface image with the brightness value of the target imaging region for the image volume data, the purpose is to cover the entire surface of the substrate. The image of the imaging region to be imaged can be taken out. In this case, even if the light source, for example, the fluorescent lamp is slanted at the time of imaging, or the position of the light source is deviated for each photograph, the region of the predetermined luminance value is common, so that the predetermined luminance value is used. By dividing, the image of the target imaging region can be taken out regardless of the number of photographs, and unevenness and color unevenness can be detected more easily.

As described above, by treating the image of the substrate surface obtained in the first image processing step as image volume data, the brightness and the like are set, the image volume data of the substrate surface is divided, and the isosurface (isosurface). ) Can be taken out.
(2) Arbitrary Steps that the Substrate Inspection Method of the Present Embodiment Can Have The Substrate Inspection Method of the present embodiment may further have any other steps.
(Inclination correction process)
For example, it may further have an inclination correction step of leveling the substrate arranged on the substrate stage.

The specific method for adjusting the horizontality of the substrate is not particularly limited, but for example, the stage 11 for the substrate or the housing (framework) of the inspection device 10 for the substrate is provided with an inclination correction means for adjusting the horizontality, and is automatically or manually adjusted. The levelness can be adjusted by.
(Second light irradiation start step, second image change step, second imaging step, second image processing step)
Further, as described above, the substrate inspection device 10 may further include a second display 18 and the like on the second surface 12B side of the substrate 12.
Then, when the substrate inspection device includes these members, that is, when the second display is arranged on the second surface side located on the side opposite to the first surface of the substrate, the present embodiment The substrate inspection method may further include the following steps.

A second light irradiation start step of displaying an image on the second image display surface of the second display by the second control means and irradiating the second surface side of the substrate installed on the substrate stage with light.
A second image changing step of changing the image displayed on the second image display surface of the second display by the second control means.
A second imaging step in which the first surface of the substrate is imaged by an imaging means between the second light irradiation start step and the second image changing step.
A second image processing step of processing the image obtained in the second imaging step.

Hereinafter, each step will be described.
(Second light irradiation start process)
In the second light irradiation start step, the second control means can display an image on the second image display surface of the second display and irradiate the second surface side of the substrate installed on the substrate stage with light.

Since the second display, the second image display surface, the second control means, and the like have already been described, detailed description thereof will be omitted.

As an image to be displayed on the second image display surface of the second display by the second control means, for example, an image including a linear first luminance region and a second luminance region having a lower luminance than the first luminance region is included. Can be mentioned. For example, it is possible to control a table that displays an image including a linear white first luminance region in a black second luminance region. The color of each area here is an example, and can be arbitrarily selected according to the color of the substrate to be projected and the like.

Since the specific shape and the like of the first luminance region have already been described, the description thereof will be omitted here.

In particular, as described above, from the viewpoint of increasing the number of transmission regions formed on the first surface of the substrate and improving the efficiency of inspection, a plurality of second control means 19 are provided on the first surface of the substrate 12. It is preferable to select an image to be displayed on the second image display surface 18A of the second display 18 so that the transparent region of the above can be formed. For example, in the second light irradiation start step, the second control means 19 has a plurality of linear first luminance regions parallel to each other on the second image display surface 18A of the second display 18, and more than the first luminance region. It is preferable to display an image including a second brightness region having low brightness. The first luminance region and the second luminance region can be formed alternately. In this case, it is preferable that the second control means 19 moves the plurality of first luminance regions in the direction perpendicular to the longitudinal direction of the first luminance region in the second image changing step described later.

In the second image changing step described later, the position of the transmission region on the first surface of the substrate is moved, and the image of the portion to be inspected when the images captured by the imaging means are joined, for example, the entire surface of the substrate. It is preferable that the image of the above can be formed. Therefore, in the second light irradiation start step, for example, it is preferable that a transmission region can be formed at or near the first end portion which is an arbitrary end portion on the surface of the substrate. Therefore, the second control means adjusts the image and the position so that the first end portion, which is an arbitrary end portion of the second surface of the substrate, can be irradiated with the light emitted from the first luminance region. It is preferable to keep it.
(Second image change process)
In the second image changing step, the image displayed on the second image display surface of the second display can be changed by the second control means. Thereby, the position of the transmission region can be changed on the first surface of the substrate.

The conditions for moving the position of the transmission region on the first surface of the substrate in the second image change step are not particularly limited, but as described above, the position of the transmission region is moved in the second image change step. It is preferable that an image of a portion to be inspected when the images of the transmission region captured by the imaging means are stitched together, for example, an image of the entire surface of the substrate can be formed. Therefore, in the second image changing step, the transmission region is set along the direction orthogonal to the longitudinal direction of the transmission region, and the end portion opposite to the first end portion described in the second light irradiation start step. That is, it is preferable to move the straight line passing through the first end portion and the center of the substrate to the second end portion orthogonal to the end portion of the substrate because it is efficient and the substrate surface can be imaged without gaps.

In the second image changing step, the transmission region may be continuously moved or may be moved intermittently. For example, the moving conditions of the transmission region can be selected according to the performance of the imaging means and the like.

Moving the transparent region continuously means, for example, moving the transparent region continuously without stopping. In this case, in the second imaging step described later, the transmission region can be imaged at an arbitrary timing and interval.

Further, when the transmission region is intermittently moved, the second image changing step and the second imaging step can be alternately performed. That is, in the second image changing step, the transmission region is moved by a certain distance by changing the image (still image) displayed on the second image display surface of the second display, and then the second imaging step is performed, and the second imaging step is performed again. After performing the two image change steps, the second imaging step can be carried out.

The moving speed of the transmission region or the moving distance at one time in the second image changing step is not particularly limited, and can be arbitrarily selected based on the size of the unevenness on the surface of the substrate to be detected, the efficiency of inspection, and the like.

When moving the transmission region in the second image change step, for example, the second imaging step is performed every time the transmission region is moved by a certain amount, the transmission region is imaged, and the transmission region is joined in the second image processing step described later. can. Then, it is preferable to form an image of a portion to be inspected, for example, an image of the entire surface of the substrate by joining a plurality of images of a target imaging region captured in the second imaging step. Therefore, in the second image change step, after the transmission region is imaged in the nth second imaging step, the distance to move the transmission region until the transmission region is imaged in the n + 1th second imaging step is connected. It is preferable to move the bright region so that it matches the width of the image, that is, the width of the transparent region.
(Second imaging step)
In the second imaging step, the first surface of the substrate can be imaged by the imaging means from the second light irradiation start step to the second image changing step. Specifically, the above-mentioned transmission region can be imaged.

In the second imaging step, at least a region including a transmission region may be photographed, and the periphery of the transmission region may also be imaged. When the region around the transmission region is also imaged, the target transmission region can be cut out from the captured image in the second image processing step described later.

Since the transparent region has already been described with reference to FIG. 4, the description thereof will be omitted here.

The image captured in the second imaging step may be a moving image or a still image. In the case of moving images, for example, in the second image processing step described later, a plurality of still images in the imaging region at arbitrary timings can be extracted and stitched together from the captured images.

When the captured images are three-dimensionally collected and handled as image volume data in the second image processing step, the entire surface of the substrate including the transmission region may be imaged in the second image processing step.
(Second image processing process)
In the second image processing step, the image obtained in the second imaging step can be processed.

Specifically, for example, the images captured in the second imaging step are processed into a linear shape (strip shape) like the transmission region shown in FIG. 4 as necessary, arranged along the moving direction of the transmission region, and joined together. This makes it possible to obtain an image of the entire surface of the substrate. At this time, the contrast in the image can be corrected as needed.

When a line scan camera is used as the imaging means 15 and a linear (strip-shaped) image is acquired, the acquired images can be arranged and joined as they are without being processed.

Further, when a moving image is captured in the second imaging step, a plurality of still images in the transmission region at a predetermined timing can be extracted in the second image processing step.

Then, for example, by outputting the image obtained in the second image processing step to the output means and visually or performing image processing, the surface of the substrate, specifically, the first surface of the substrate and the second surface can be subjected to. Unevenness can be detected.

In the second image processing step, for example, AI can be used to detect and notify the unevenness of the substrate surface from the image of the substrate surface obtained as described above. Further, in the second image processing step, for example, it can be configured so that a portion of the formed image in which unevenness is generated can be detected and notified by a preset threshold value such as chromaticity or lightness.

The image processing in the second image processing step is not limited to the above method, and for example, the images captured in the second imaging step can be three-dimensionally collected and handled as image volume data.

Then, in the second image processing step, volume rendering processing can also be performed on the image volume data of the first surface of the substrate obtained in the second imaging step. In the second image processing step, specifically, for example, by creating (rendering) an isosurface image with the brightness value of the transmission region for the image volume data, the image of the transmission region is created over the entire surface of the substrate. Can be taken out. In this case, even if the light source, for example, the fluorescent lamp is slanted at the time of imaging, or the position of the light source is deviated for each photograph, the region of the predetermined luminance value is common, so that the predetermined luminance value is used. By dividing, the image in the transparent region can be taken out regardless of the number of photographs, and the color unevenness can be detected more easily.

As described above, by treating the image of the substrate surface obtained in the second image processing step as image volume data, the brightness and the like are set, the image volume data of the substrate surface is divided, and the isosurface (isosurface). ) Can be taken out.

Further, in the second image processing step, for example, an image obtained by connecting the first imaging region and the second imaging region described above obtained in the first image processing step described above and a second image processing step as needed. It is also possible to superimpose the image obtained by joining the transmission regions obtained in 1) so that the positions of the color unevenness and the unevenness of the first surface and the second surface of the substrate can be compared and confirmed.

Although the first image processing step and the second image processing step have been described here as separate steps, both steps can be simultaneously carried out as one step.

According to the substrate inspection method of the present embodiment described above, the unevenness of the substrate surface and the unevenness of the substrate surface can be easily obtained by using a substrate inspection device having a simple structure including a display, an imaging means, and a stage for the substrate. It becomes possible to detect color unevenness.

Further, in the substrate inspection method of the present embodiment, by changing the image displayed on the image display surface of the display, the substrate can be inspected without moving the light source or the imaging means. Therefore, the entire inspection device for the substrate to be used can be miniaturized, and the cost can be suppressed.

10, 50 Substrate inspection device 11 Substrate stage 12 Substrate 12A First surface 12B Second surface 13 First display 13A First image display surface 14 First control means 15 Imaging means 16 Image processing means 18 Second display 18A Second image display surface 19 Second control means 21 First brightness region 22 Second brightness region 31A Bright region 32A, 32B First imaging region 33 Second imaging region 41A Transmission region 51 Half mirror

Claims (11)

The board stage on which the board is installed and
A first display provided with a first image display surface which is a light source of light irradiating the first surface side of the substrate installed on the substrate stage.
A first control means for controlling an image displayed on the first image display surface of the first display, and
An imaging means for imaging the first surface side of the substrate, and
A substrate inspection device including an image processing means for processing an image obtained by the imaging means. The substrate inspection apparatus according to claim 1, further comprising a half mirror on the optical path of the light irradiating the first surface side of the substrate from the first image display surface of the first display. A second display provided with a second image display surface, which is a light source for irradiating a second surface side of the substrate opposite to the first surface side.
The substrate inspection apparatus according to claim 1 or 2, further comprising a second control means for controlling an image displayed on the second image display surface of the second display. The substrate inspection apparatus according to any one of claims 1 to 3, wherein the imaging means is a line scan camera. The substrate inspection apparatus according to any one of claims 1 to 4, further comprising an inclination correcting means for leveling the substrate. The first control means has a plurality of linear first luminance regions parallel to each other and a second luminance region having a lower luminance than the first luminance region on the first image display surface of the first display. The substrate inspection apparatus according to any one of claims 1 to 5, which displays an image including the image and moves the first luminance region in a direction perpendicular to the longitudinal direction of the first luminance region. A first light irradiation start step of displaying an image on the first image display surface of the first display by the first control means and irradiating the first surface side of the substrate installed on the substrate stage with light.
A first image changing step of changing an image displayed on the first image display surface of the first display by the first control means,
Between the first light irradiation start step and the first image change step, a first imaging step of imaging the first surface side of the substrate by an imaging means, and a first imaging step.
A method for inspecting a substrate, comprising a first image processing step of processing an image obtained in the first imaging step. The second display is arranged on the second surface side of the substrate, which is located on the side opposite to the first surface of the substrate.
A second light irradiation start step of displaying an image on the second image display surface of the second display by the second control means and irradiating the second surface side of the substrate installed on the substrate stage with light. When,
A second image changing step of changing the image displayed on the second image display surface of the second display by the second control means,
Between the second light irradiation start step and the second image change step, a second imaging step of imaging the first surface side of the substrate by an imaging means, and a second imaging step.
The substrate inspection method according to claim 7, further comprising a second image processing step of processing the image obtained in the second imaging step. The substrate inspection method according to claim 7 or 8, wherein the imaging means is a line scan camera. The method for inspecting a substrate according to any one of claims 7 to 9, further comprising a tilt correction step for leveling the substrate. The first control means
In the first light irradiation start step, a plurality of linear first luminance regions parallel to each other and a second luminance region having a lower luminance than the first luminance region are provided on the first image display surface of the first display. Display images containing and
The method for inspecting a substrate according to any one of claims 7 to 10, wherein in the first image changing step, the first luminance region is moved in a direction perpendicular to the longitudinal direction of the first luminance region.

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