JP2021125487A - Board inspection device and board inspection method - Google Patents

Abstract

To provide a board inspection device capable of detecting color unevenness on a substrate surface.SOLUTION: A board inspection device includes a board stage on which a board is installed, a first light source that irradiates the first surface side of the board installed on the board stage with linear light, first imaging means that images an imaging region which is a region other than a bright region which is a region that reflects the linear light emitted from the first light source along the longitudinal direction of the bright region in the first surface of the board, first irradiation position control means that changes the position of the bright region, and first image processing means that processes the image obtained by the first 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 inspection device capable of detecting color unevenness on the substrate surface caused by non-uniform composition of the surface of the substrate after a reaction process such as heat treatment or non-uniform thickness has been used. I was asked.

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 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 light source that irradiates the first surface side of the substrate installed on the substrate stage with linear light, and
Of the first surface of the substrate, an imaging region that is a region other than the bright region along the longitudinal direction of the bright region, which is a region that reflects the linear light emitted from the first light source. The first imaging means for imaging and
The first irradiation position control means for changing the position of the bright region and
Provided is a substrate inspection apparatus having a first image processing means for processing an image obtained by the first imaging means.

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

Sectional drawing of the inspection apparatus which concerns on 1st Embodiment of this invention. Explanatory drawing of a bright region and an imaging region. Sectional drawing of the inspection apparatus which concerns on 2nd Embodiment of this invention. Explanatory drawing of the transparent area. Sectional drawing of the inspection apparatus which concerns on 3rd Embodiment of this 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 non-uniformity of the composition of the substrate surface. During the study, when the surface side of the substrate is irradiated with linear light, the region of one surface of the substrate that reflects the linear light, that is, the region other than the bright region directly irradiated with light is observed. Therefore, we focused on the fact that color unevenness on the substrate 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. The present invention was completed by finding that an image was obtained.
(1) First Embodiment FIG. 1 shows a cross-sectional view of a plane passing through the center of a substrate 12 arranged on a substrate stage 11 of a substrate inspection device 10 according to the first embodiment.

The substrate inspection device 10 of the present embodiment is a first light source that irradiates linear light to the substrate stage 11 on which the substrate is installed and the first surface 12A side of the substrate 12 installed on the substrate stage 11. It can have 13, a first imaging means 14, a first irradiation position control means 15, and a first image processing means 16.

The first imaging means 14 is a region other than the bright region along the longitudinal direction of the bright region, which is a region of the first surface 12A of the substrate 12 that reflects the linear light emitted from the first light source 13. It is possible to image the imaging region.

The first irradiation position control means 15 can change the position of the bright region.

The first image processing means 16 can process the image obtained by the first imaging means 14.

Each member 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.

However, for example, when the substrate 12 is moved to move the bright region by the first irradiation position control means 15, the substrate stage 11 should be provided with a moving mechanism so that the substrate stage 11 can be moved in the horizontal direction. Can be done. Further, for example, a means for correcting the inclination of the substrate 12 installed on the stage 11 for the substrate and making it horizontal, for example, an inclination correction means described later may be provided.

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.
(First light source)
The first light source 13 may be configured so as to irradiate the first surface 12A side of the substrate 12 installed on the substrate stage 11 with linear light, and the specific configuration such as the type of the light source may be described. There is no particular limitation. As described above, the first light source 13 can be arranged on the first surface 12A side of the substrate 12 installed on the substrate stage 11 so that the first surface 12A side of the substrate 12 can be irradiated with linear light. ..

The first light source 13 does not need to directly irradiate the first surface 12A of the substrate 12, but may irradiate the vicinity of the first surface 12A of the substrate 12. However, the first surface 12A of the substrate 12 may be directly irradiated with light.

The linear light may have a linear shape, and the specific shape thereof is not particularly limited. For example, from linear light, linear light including a bent portion, wavy linear light, and the like. It can be any of the selected lights. The shape of the bent portion of the linear light 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 linear light bending portions including the bending portion is not particularly limited, and one or more bending portions may be provided. When the linear light 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 light becomes linear light in which the bent portions are arranged while alternately changing the directions at predetermined intervals so as to be wavy lines. The linear light is particularly preferably linear light.

Since linear light is light having a certain thickness, it can be paraphrased as band-shaped light. For example, in the case of linear light, the light is substantially square.

The length of the linear light in the longitudinal direction is not particularly limited, but when the light is irradiated so that the longitudinal direction of the linear light is along the width direction of the substrate to be inspected, from the viewpoint of efficient inspection. For example, it is possible to irradiate light over the entire width direction of the substrate to be inspected and select its length so that a bright region can be formed.

As the light emitting means of the light source, it is sufficient that linear light can be formed, and for example, one or more selected from fluorescent lamps, organic or inorganic electroluminescence (EL), light emitting diodes and the like can be used.

Further, the wavelength of light is not particularly limited as long as it can reflect at least a part of light on the first surface 12A of the substrate 12 to be evaluated and the reflected image can be imaged by the first imaging means 14. Therefore, the light emitted by the light source may be, for example, infrared light, visible light, or ultraviolet light, but the light source emits light because the imaging means may become expensive or its size may increase depending on the wavelength of the light. The light preferably contains visible light.

In the substrate inspection apparatus of the present embodiment, imaging is performed along the longitudinal direction of the bright region, which is a region of the substrate surface that reflects linear light emitted from the first light source 13, and is a region other than the bright region. The region can be imaged by the first imaging means 14. Then, the imaging region is photographed while changing the position of the bright region until an image of a portion to be inspected when the obtained images of the imaging region are joined, for example, an image of the entire substrate surface is obtained. It is preferable to carry out.

Therefore, from the viewpoint of improving the efficiency of the inspection by increasing the number of imaging regions that can be simultaneously imaged and reducing the number of imagings, it is preferable that the first light source 13 can simultaneously irradiate a plurality of linear lights parallel to each other. Therefore, it is preferable that the first light source 13 is configured so that a plurality of linear lights parallel to each other can be applied to the surface of the substrate. In this case, it is necessary to adjust the interval between the plurality of linear lights so that a dark region is formed between the plurality of bright regions that reflect the plurality of linear lights irradiating the substrate. preferable. When irradiating the surface of the substrate with a plurality of linear lights, the linear lights may have the same shape or different shapes. However, it is preferable that the plurality of linear lights have the same shape because the inspection can be easily performed.

For example, as shown in FIG. 1, the first light source 13 can be fixed to an arm 17 installed in the inspection device 10 of the substrate. However, the present invention is not limited to this, and the first light source 13 can be fixed by using a tripod or the like separately from other members.
(First imaging means)
The first imaging means 14 is an imaging region other than the bright region along the longitudinal direction of the bright region that reflects the linear light emitted from the first light source 13 in the first surface 12A of the substrate 12. The area can be imaged.

Here, an imaging region to be imaged by the first imaging means 14 will be described with reference to FIG.

FIG. 2 shows the first surface 12A of the substrate 12, and shows a state in which linear light is emitted from the first light source 13. By irradiating the first surface 12A of the substrate 12 with linear light from the first light source 13 in this way, the light reflected from the first light source 13 is reflected on the first surface 12A of the substrate 12. Region 21A is formed. The bright region 21A is a linear (band-shaped) region corresponding to the linear light from the first light source 13.

The region other than the bright region 21A of the first surface 12A of the substrate 12 is a dark region 21B that is darker than the bright region 21A because the light from the light source is not directly irradiated.

The first imaging means 14 captures an imaging region 22 other than the bright region 21A, that is, surrounded by a dotted line in the dark region 21B, for example, along the longitudinal direction of the bright region 21A, that is, along the X-axis direction in the drawing. It can be imaged. In this case, at least the region including the imaging region 22 may be photographed, and the periphery of the imaging region 22 may also be imaged. When the area around the imaging region 22 is also imaged, an image of the target imaging region can be cut out from the captured image by the first image processing means described later.

Here, the case where the light from the first light source 13 is directly irradiated to the first surface 12A of the substrate 12 has been described as an example, but as described above, the light from the first light source 13 is , It is not necessary that the first surface 12A of the substrate 12 is directly irradiated. For example, the light emitted from the first light source 13 may be applied 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, it is preferable that the degree of brightness in the imaging region 22 due to the light from the first light source 13 is uniform. Therefore, as described above, the first surface 12A of the substrate 12 or its vicinity is irradiated with light from the first light source 13, the imaging region 22 is set along the longitudinal direction of the bright region 21A, and imaging is performed. Is preferable. In addition, the region of the imaging region 22 so that the degree of brightness in the imaging region 22 due to the light from the first light source 13 is not excessively long in the direction perpendicular to the longitudinal direction of the imaging region 22. It is preferable to set. The length in the direction perpendicular to the longitudinal direction of the 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 captured imaging region by the first 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 imaging regions constituting the image of the entire surface of the substrate is uniform. Therefore, when the position of the bright region formed by irradiating the linear light from the first light source 13 is changed, it is preferable to keep the distance between the bright region and the imaging region 22 constant.

When the captured images are collected three-dimensionally and handled as image volume data as described later, the first imaging means 14 may image the entire first surface 12A of the substrate 12 including the imaging region. ..

According to the study of the inventor of the present invention, when the surface of the substrate is irradiated with linear light, the bright region on the surface of the substrate that reflects the linear light and the dark region adjacent to the bright region are defined. In the vicinity of the boundary, the contrast of the unevenness on the substrate surface is increased. 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. An image that clarifies is obtained.

Therefore, when it is necessary to inspect the unevenness of the first surface 12A of the substrate 12, for example, from the unevenness detection imaging regions 23A and 23B including the bright region 21A and the dark region 21B adjacent to the bright region 21A. One or more selected regions can also be imaged by the first imaging means 14. In addition, in order to image the unevenness detection imaging region, an imaging means different from the first imaging means 14 may be provided.

In the unevenness detection imaging region 23A, which is the upper region of the bright region 21A, and the unevenness detection imaging region 23B on the lower side of the bright region 21A, the arrangement of the bright region and the dark region included in each imaging region is reversed. It has become. Therefore, the black and white (brightness) of the obtained image is reversed between the case where the images in the unevenness detection imaging region 23A are joined and the case where the images in the unevenness detection imaging region 23B are joined. Therefore, it is possible to select an imaging region to be imaged according to the image to be acquired.

The first imaging means 14 may be able to image an imaging region 22 other than the bright region 21A along the longitudinal direction of the bright region 21A formed on the substrate 12 as described above, and its configuration is not particularly limited. As the first image pickup means 14, 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 first imaging means 14 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 the first image processing means described later.

Further, since the first imaging means 14 may be any means capable of imaging a linear (strip-shaped) imaging region depending on the shape of the bright region or the like, the first imaging means may be, for example, a line scan camera. .. 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 first imaging means 14 may be fixed to an arm 18 installed in the substrate inspection device 10 as shown in FIG. 1, for example. The first light source 13 described above can also be fixed to the arm 18. However, the present invention is not limited to this, and the first imaging means 14 can be fixed by using a tripod or the like separately from other members.
(First irradiation position control means)
As described above, in the substrate inspection apparatus of the present embodiment, the imaging region of the first surface of the substrate along the longitudinal direction of the bright region and the region other than the bright region is imaged by the first imaging means. can. Then, while changing the position of the bright region, the image of the portion to be inspected when the images of the obtained imaging region are joined to image the imaging region, for example, the image of the entire first surface of the substrate is obtained. It is preferable to carry out repeatedly until it is obtained.

Therefore, the substrate inspection device of the present embodiment can have a first irradiation position control means 15 that changes the position of a bright region formed on the first surface of the substrate.

The first irradiation position control means 15 can move, for example, the bright region in a direction orthogonal to the longitudinal direction of the bright region, that is, in the Y-axis direction in FIG. In this case, for example, the first irradiation position control means 15 can control the movement of at least one of the substrate stage 11 and the first light source 13.

For example, when the longitudinal direction of the linear light emitted by the first light source 13 is orthogonal to the first arrow 11A in FIG. 1, the substrate stage 11 is set in the direction of the first arrow 11A in FIG. Alternatively, the substrate 12 installed on the substrate stage 11 can be moved by moving it in the direction opposite to the first arrow 11A. As a result, the position of the bright region formed on the substrate 12 can be moved in the direction orthogonal to the longitudinal direction of the bright region.

Further, the first light source 13 can be fixed to the arm 17 as shown in FIG. 1, for example, as described above, and the arm 17 can be fixed in the direction of the second arrow 17A in the drawing or the second arrow 17A. By moving the light in the direction opposite to the above, the irradiation position of the linear light from the first light source 13 can be changed. Therefore, the position of the bright region can also be moved.

Therefore, for example, a driving means for moving or rotating each member, such as a motor, may be provided on at least one member selected from the stage 11 for the substrate and the arm 17 to which the first light source 13 is fixed. can. Then, the first irradiation position control means 15 can be connected to the driving means and can control the displacement amount and the direction of the displacement.

When the first light source 13 is moved, the first imaging means 14 can also be configured to be movable according to a change in the irradiation position of linear light.

The moving direction of the bright region is not limited to the direction orthogonal to the longitudinal direction of the bright region, and for example, the bright region may be configured to rotate along the circumferential direction of the substrate. In this case, a driving means such as a motor can be arranged so that the substrate stage 11 rotates in a horizontal plane, and the first irradiation position controlling means 15 can be connected to the driving means.

As the first irradiation position control means 15 moves the bright region formed on the first surface of the substrate, the imaging region to be imaged by the first imaging means 14 is also moved, and the images captured in the imaging region are stitched together. In this case, it is preferable that an image of the portion to be inspected, for example, an image of the entire surface of the substrate can be formed. Therefore, for example, after forming a bright region at or near the first end, which is an arbitrary end of the first surface of the substrate, the bright region is set along a direction orthogonal to the longitudinal direction of the bright region. It is efficient and efficient to move the surface of the substrate to the opposite side of the first end, that is, to the second end where the straight line passing through the first end and the center of the substrate is orthogonal to the end of the substrate. It is preferable because it can image without gaps.

When the bright region is moved by the first irradiation position control means 15, for example, every time the bright region is moved by a certain amount, the imaging region is imaged by the first imaging means 14 and connected by the first image processing means 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 the images of a plurality of imaging regions captured by the first imaging means 14. Therefore, after the nth imaging region is imaged by the first imaging means, the distance at which the bright region is moved by the first irradiation position control means before the n + 1th imaging region is imaged, and the width of the images to be stitched, that is, It is preferable to move the bright region so that it matches the width of the imaging region.
(First image processing means)
The first image processing means 16 can process the image captured by the first imaging means 14.

The first image processing means 16 is an ASIC (application specific integrated circuit: an integrated circuit for a specific application) or the like, and is in charge of processing an image captured by the first imaging means 14.

In the first image processing means 16, for example, a strip-shaped image corresponding to the above-mentioned imaging region is cut out from the image captured by the first imaging means 14, arranged along the moving direction of the bright region, and connected. By combining them, 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 a moving image is captured by the first imaging means 14, the first image processing means 16 can also extract a plurality of still images in the imaging region at a predetermined timing.

The image created by the first image processing means 16 can also be output to the first output means 19, and color unevenness can be visually detected from the obtained image due to the difference in contrast in the obtained image. The configuration of the first output means 19 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 first image processing means 16 can be provided with, for example, an AI (artificial intelligence), and can detect and notify color unevenness of the first surface of the substrate from the image of the substrate surface obtained as described above. It can also be configured to do so. Further, the first image processing means or the like can be configured so that a portion of the formed image in which color unevenness occurs can be detected and notified by, for example, a preset threshold value such as chromaticity or lightness. ..

The first 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 first image processing means 16 can also three-dimensionally collect the images captured by the first imaging means 14 and handle them as image volume data. Then, the first image processing means 16 can perform volume rendering processing on the image volume data on the surface of the substrate obtained by the first imaging means 14. Specifically, for example, the first image processing means 16 creates (renders) an isosurface image at the brightness value of the imaging region for the image volume data, so that the image of the imaging region covers 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 target imaging region can be taken out regardless of the number of photographs, and color unevenness can be detected more easily.

By treating the obtained image of the substrate surface as image volume data in the first image processing means 16, the brightness and the like are set according to the size of the color unevenness to be detected, and the image volume data of the substrate surface is divided. , The isosurface can be extracted.

As described above, when the imaging region for unevenness detection is also imaged, the first image processing means 16 cuts out, for example, a strip-shaped image corresponding to the imaging region for unevenness detection described above as necessary. By arranging and joining the regions along the moving direction, it is possible to form an image of the entire surface of the substrate. At this time, it is also possible to correct the contrast and the like in the formed image as needed.

Further, for example, the first image processing means 16 may be provided with, for example, AI so as to detect and notify the concave portion or the convex portion of the substrate surface from the obtained image of the first surface of the substrate. It can also be configured.

The first image processing means 16 can also perform volume rendering processing on the image volume data on the surface of the substrate obtained by the first imaging means 14. Specifically, for example, the first image processing means 16 creates (renders) an isosurface image at the brightness value of the boundary between the bright region and the dark region for the image volume data, thereby covering the entire surface of the substrate. Across, the boundary (image of the boundary) between the bright area and the dark area can be extracted. In this case, even if the light source, for example, the fluorescent lamp is slanted when taking an image, or the position of the light source is deviated for each photograph, the boundary surface is the same. Regardless of the number of sheets, the boundary between the bright region and the dark region can be taken out, and the concave portion and the convex portion can be detected more easily.

By treating the obtained image of the substrate surface as image volume data in the first image processing means 16, the brightness and the like are set according to the size of the unevenness to be detected, and the image volume data of the substrate surface is divided. The isosurface can be extracted.

It is also possible to provide an image processing means separately from the first image processing means 16 to perform the above-described processing on the image in the unevenness detection imaging region. Then, the image processing of the image in the image pickup region for detecting unevenness can be output to the first output means 19 or the like described above as necessary, and the unevenness on the first surface of the substrate can be visually detected.

The substrate inspection device of the present embodiment may further include any member in addition to the above-mentioned members.

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.

Further, here, an example in which the first light source 13 and the first imaging means 14 are provided only on the first surface 12A side of the substrate 12, but the present invention is not limited to this. For example, a second light source and a second imaging means are provided on the second surface 12B side of the substrate 12, so that the presence or absence of color unevenness on the first surface 12A and the second surface 12B of the substrate 12 can be inspected at the same time. It can also be configured to. In this case, it is also possible to further have a light source control means for controlling the light emission of the first light source and the second light source so that the light from the first light source and the light from the second light source do not interfere with each other. The light source control means can control, for example, the first light source and the second light source to be turned on alternately.

According to the substrate inspection apparatus of the present embodiment described above, it is possible to easily detect color unevenness on the substrate surface by a simple apparatus configuration including a light source, an imaging means, and a stage for the substrate.

Further, in the substrate inspection device of the present embodiment, a light source that emits linear light is sufficient, and it is not necessary to use, for example, a large flat plate-shaped light source. Therefore, the entire substrate inspection device can be miniaturized, and the cost can be suppressed.
(2) Second Embodiment FIG. 3 shows a cross-sectional view of a plane passing through the center of the substrate 12 arranged on the substrate stage 11 of the substrate inspection device 30 according to the second embodiment.

In the substrate inspection device 30 of the present embodiment, in addition to the configuration of the substrate inspection device 10 described above, the first light source of the second surface 12B located on the opposite side of the first surface 12A of the substrate 12 A second imaging means for imaging a transmission region, which is a region that transmits linear light emitted from the light source.
It is also possible to further have a second image processing means for processing the image obtained by the second imaging means.

The members described in the first embodiment are designated by the same numbers, and the description thereof will be omitted.

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 there are recesses or the like on the surface of the substrate and the thickness of the substrate is not uniform, it may be detected as color unevenness on the first surface side. Therefore, it is more preferable to detect the unevenness of the surface of the substrate as well, and to confirm whether the cause is, for example, a recess on the surface side of the substrate.

Therefore, the inventor of the present invention has diligently studied a substrate inspection device capable of detecting unevenness on the surface of the substrate. During the study, among the second surfaces located on the opposite side of the first surface of the substrate when the first surface, which is one surface of the substrate, is irradiated with linear light from a light source. We focused on the fact that the contrast of the unevenness on the surface of the substrate increases in the transmission region where the linear light emitted from the light source is transmitted. Then, the operation of imaging (photographing) the transmission region on the second 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 surface of the substrate. It was found that an image with clear unevenness can be obtained.

Among the members included in the substrate inspection device 30 of the present embodiment, each member not described in the first embodiment will be described below.
(Second imaging means)
The substrate inspection device 30 of the present embodiment includes a second imaging means 34 on the second surface 12B side of the substrate 12.

The second imaging means 34 sets a transmission region, which is a region of the second surface 12B located on the opposite side of the first surface 12A of the substrate 12, which is a region through which the linear light emitted from the first light source 13 is transmitted. It can be imaged.

Here, a transmission region to be imaged by the second imaging means 34 will be described with reference to FIG.

FIG. 4 shows the second surface 12B side of the substrate 12, which is opposite to the second surface 12B of the substrate 12, that is, the back surface is the first surface, and the first surface is linear from the light source. It becomes the surface to be irradiated with the light of. Then, FIG. 4 shows a state in which the first surface is irradiated with one linear light from the first light source, and the corresponding transmission region 41A is formed on the second surface 12B.

When the first surface 12A of the substrate 12 is irradiated with linear light from the first light source, a transmission region 41A that transmits the light from the light source is formed on the second surface 12B of the substrate 12. The transmission region 41A is a linear (band-shaped) region corresponding to the linear light from the first light source.

Since the regions other than the transmission region 41A have a low degree of light transmission from the light source or are not transmitted, they are darker dark regions than the transmission region 41A, and the dark region 41B is formed on the substrate 12. It is formed.

In this case, the second 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 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 second image processing means described later.

The second imaging means only needs to be able to image the transmission region formed on the substrate as described above, and its configuration is not particularly limited. As the second image pickup means 34, a camera module including various image pickup elements can be used. As the image pickup device, the same image pickup device as that described in the first image pickup means of the first embodiment can be used, and thus the description thereof will be omitted here.

The image captured by the second imaging means 34 may be a moving image or a still image. In the case of moving images, for example, a second image processing means described later can be used to extract and use a plurality of still images in the transmission region at arbitrary timings from the captured images.

Further, the second imaging means 34 may be a line scan camera, for example, because it is sufficient if the second imaging means 34 can image a linear (band-shaped) bright region depending on the shape of the transmission region or the like. ..

The second imaging means 34 may be fixed to an arm 38 installed in the substrate inspection device 30 as shown in FIG. 3, for example. However, the present invention is not limited to this, and the second imaging means 34 can be fixed by using a tripod or the like separately from other members. Further, it is also possible to provide a moving means for the second imaging means or the like so that the position of the second imaging means 34 moves as the transmission region moves.

Since the transmission region is the light from the first light source, the position on the second surface of the substrate is displaced by the above-mentioned first irradiation position control means.
(Second image processing means)
The second image processing means 36 can process the image captured by the second imaging means 34.

The second image processing means 36 is an ASIC or the like, and is in charge of processing the image captured by the second imaging means 34.

In the second image processing means 36, for example, a strip-shaped image corresponding to the transmission region is cut out from the image captured by the second imaging means 34 as needed, arranged along the moving direction of the transmission region, and joined together. , An image of the entire second surface of the substrate can be formed. At this time, the contrast in the image can be corrected as needed.

When a moving image is captured by the second imaging means 34, the second image processing means 36 can also extract a plurality of still images in the transmission region at a predetermined timing.

Then, the image created by the second image processing means 36 can be output to the second output means 39, and unevenness can be visually detected from the obtained image due to the difference in contrast in the obtained image. Further, since the transmitted light is used in the substrate inspection device 30 of the present embodiment, not only the unevenness contained in the second surface 12B of the substrate but also the unevenness contained in the first surface 12A can be obtained. It can also be detected from the image.

The configuration of the second output means 39 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 second image processing means 36 can be provided with, for example, an AI, and is configured to detect and notify the concave portion or the convex portion of the substrate surface from the image of the substrate surface obtained as described above. You can also do it.

The second image processing means 36 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 second image processing means 36 can also three-dimensionally collect the images captured by the second imaging means 34 and handle them as image volume data. Then, the second image processing means 36 can perform volume rendering processing on the image volume data on the surface of the substrate obtained by the second imaging means 34. Specifically, for example, the second image processing means 36 creates (renders) an isosurface image with the brightness value of the transmission region for the image volume data, thereby forming an image of the transmission region 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 target transparent region can be taken out regardless of the number of photographs, and unevenness can be detected more easily.

In the second image processing means 36, by treating the obtained image of the substrate surface as image volume data, the brightness and the like are set according to the size of the unevenness to be detected, and the image volume data of the substrate surface is divided. The isosurface can be extracted.

Here, an example in which the second image processing means 36 is provided in addition to the first image processing means 16 described above has been described, but the present invention is not limited to this form, and for example, the first image processing means 16 and the first image processing means 16 and the first image processing means 16. The two image processing means 36 can be combined into one image processing means.

Further, for example, an image obtained by connecting the imaging regions obtained by the first image processing means 16 and an image obtained by connecting the transmission regions obtained by the second image processing means 36 are superposed to cause color unevenness and unevenness. It can also be configured so that the position with and can be compared and confirmed.

According to the substrate inspection apparatus of the present embodiment described above, not only color unevenness on the substrate surface but also irregularities on the substrate surface can be easily detected by a simple apparatus configuration including a light source, an imaging means, and a stage for the substrate. Will be possible.

Further, in the substrate inspection device of the present embodiment, a light source that emits linear light is sufficient, and it is not necessary to use, for example, a large flat plate-shaped light source. Therefore, the entire substrate inspection device can be miniaturized, and the cost can be suppressed.

Further, according to the substrate inspection device of the present embodiment, since the unevenness of the substrate surface is detected by using the transmitted light, the unevenness on the back surface side opposite to the surface to be imaged at the time of inspection is also detected. be able to. Therefore, it is possible to efficiently inspect the unevenness of the substrate surface on both sides of the substrate.
(3) Third Embodiment FIG. 5 shows a cross-sectional view of the substrate inspection device 50 according to the third embodiment in a plane passing through the center of the substrate 12 arranged on the substrate stage 11.

The substrate inspection device 50 of the present embodiment may further include the following members in addition to the substrate inspection device 10 described in the first embodiment.
A second light source that irradiates a second surface of the substrate opposite to the first surface with linear light.
A second irradiation position control means for changing the position of a transmission region, which is a region through which linear light emitted from a second light source is transmitted, on the first surface of the substrate.
A light source control means for controlling light emission of a first light source and a second light source.
Then, the first imaging means can also image a transmission region of the first surface of the substrate.

The members described in the first embodiment are designated by the same numbers, and the description thereof will be omitted.

As described above in the second embodiment, color unevenness on the surface of the substrate is caused by, for example, uneven composition of the surface of the substrate or non-uniform thickness of the surface of the substrate. It is more preferable to detect unevenness as well, and to confirm whether it is caused by, for example, a concave portion on the surface side of the substrate.

Therefore, in the substrate inspection device according to the present embodiment, a second light source is further provided on the second surface side of the substrate.

In the substrate inspection device of the present embodiment, the operation of imaging (imaging) the transmission region of the first surface of the substrate through which the linear light emitted from the second light source is transmitted is also performed by the first imaging means. , Can be repeated while changing the position of the transmission region. Then, by stitching the obtained images together, it is possible to obtain an image in which the unevenness of the surface of the substrate is clarified.

The transmission region in the present embodiment is the same as the transmission region 41A described with reference to FIG. 4 in the second embodiment except that the transmission region is formed on the first surface 12A side of the substrate 12. The description is omitted here. When it is necessary to distinguish from the transmission region in the second embodiment, the transmission region in the second embodiment is referred to as a first transmission region, and the transmission region in the present embodiment is referred to as a second transmission region to distinguish them. Is also good.

Among the members included in the substrate inspection device 50 of the present embodiment, each member not described in the first embodiment will be described below.
(Second light source)
The second light source 53 may be configured so as to be able to irradiate the second surface 12B of the substrate 12 installed on the substrate stage 11 with linear light, and the specific configuration such as the type of the light source is particularly limited. Not limited. As described above, the second light source 53 can be arranged on the second surface 12B side of the substrate 12 installed on the substrate stage 11 so that the second surface 12B of the substrate 12 can be irradiated with linear light.

The linear light may have a linear shape, and the specific shape thereof is not particularly limited. For example, from linear light, linear light including a bent portion, wavy linear light, and the like. It can be any of the selected lights. The shape of the bent portion of the linear light 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 linear light bending portions including the bending portion is not particularly limited, and one or more bending portions may be provided. When the linear light 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 light becomes linear light in which the bent portions are arranged while alternately changing the directions at predetermined intervals so as to be wavy lines. The linear light is particularly preferably linear light.

Since linear light is light having a certain thickness, it can be paraphrased as band-shaped light. For example, in the case of linear light, the light is substantially square.

The length of the linear light in the longitudinal direction is not particularly limited, but when the light is irradiated so that the longitudinal direction of the linear light is along the width direction of the substrate to be inspected, from the viewpoint of efficient inspection. For example, it is possible to irradiate light over the entire width direction of the substrate to be inspected and select its length so that a transmission region can be formed.

As the light emitting means of the second light source, it is sufficient that linear light can be formed, and for example, one or more selected from fluorescent lamps, organic or inorganic electroluminescence (EL), light emitting diodes and the like can be used.

Further, the wavelength of the light is not particularly limited, and any light may be transmitted as long as it can transmit at least a part of the light on the substrate 12 to be evaluated and can image the light transmitted by the first imaging means 14. Therefore, the light emitted by the light source may be, for example, infrared light, visible light, or ultraviolet light, but the light source emits light because the imaging means may become expensive or its size may increase depending on the wavelength of the light. The light preferably contains visible light.

In the substrate inspection device of the present embodiment, the transmission region, which is the region through which the linear light emitted from the second light source is transmitted, is the second surface of the second surface located on the side opposite to the first surface of the substrate. 1 The image can be taken by the imaging means. Then, while changing the position of the transmission region, the image of the transmission region is imaged, and the image of the portion to be inspected when the obtained images of the transmission region are joined, for example, the image of the entire first surface of the substrate is obtained. It is preferable to repeat the process until it is obtained.

Therefore, from the viewpoint of improving the efficiency of inspection by increasing the number of transmission regions that can be simultaneously imaged and reducing the number of times of imaging, it is preferable that the second light source can simultaneously irradiate a plurality of linear lights parallel to each other. Therefore, it is preferable that the second light source is configured so that a plurality of linear lights parallel to each other can be applied to the second surface of the substrate. In this case, it is necessary to adjust the interval between the plurality of linear lights so that a dark region is formed between the plurality of transmitted regions that have transmitted the plurality of linear lights radiated to the substrate. preferable. When irradiating the second surface of the substrate with a plurality of linear lights, the linear lights may have the same shape or different shapes. However, it is preferable that the plurality of linear lights have the same shape because the inspection can be easily performed.

The second light source 53 can be fixed to an arm 57 installed in the substrate inspection device 50, for example, as shown in FIG. However, the present invention is not limited to this, and the second light source 53 can be fixed by using a tripod or the like separately from other members.
(Second irradiation position control means)
As described above, in the substrate inspection apparatus of the present embodiment, the transmission region of the first surface of the substrate can be imaged by the first imaging means. Then, while changing the position of the transmission region, the second transmission region is imaged, which is an image of a portion to be inspected when the obtained images of the transmission region are joined, for example, the entire first surface of the substrate. It is preferable to repeat the process until an image is obtained.

Therefore, in the substrate inspection device of the present embodiment, the position of the transmission region formed on the first surface of the substrate is changed by changing the position of the linear light irradiating the second surface of the substrate from the second light source. The second irradiation position control means 55 can be provided.

The second irradiation position control means 55 can, for example, move the transmission region in a direction orthogonal to the longitudinal direction of the transmission region. In this case, for example, the second irradiation position control means 55 can control the movement of at least one of the substrate stage 11 and the second light source 53.

For example, when the longitudinal direction of the linear light emitted by the second light source 53 is orthogonal to the first arrow 11A in FIG. 5, the substrate stage 11 is set in the direction of the first arrow 11A in FIG. Alternatively, the substrate 12 installed on the substrate stage 11 can be moved by moving it in the direction opposite to the first arrow 11A. As a result, the position of the linear light emitted from the second light source on the second surface of the substrate is moved, and the position of the transmission region formed on the first surface of the substrate is defined as the longitudinal direction of the transmission region. It can move in orthogonal directions.

As described above, the second light source 53 can be fixed to the arm 57, for example, as shown in FIG. 5, and the arm 57 is directed in the direction of the third arrow 57A in the drawing or opposite to the third arrow 57A. By moving in the direction of, the irradiation position of the linear light from the second light source 53 can be changed. Therefore, the position of the transparent region can also be moved.

Therefore, for example, a driving means for moving or rotating each member, such as a motor, may be provided on at least one member selected from the stage 11 for the substrate and the arm 57 to which the second light source 53 is fixed. can. Then, the second irradiation position control means 55 can be connected to the driving means and can control the displacement amount and the direction of the displacement.

It should be noted that the first imaging means 14 can be configured to move as the transmission region moves.

The moving direction of the transmission region is not limited to the direction orthogonal to the longitudinal direction of the transmission region, and for example, the transmission region may be configured to rotate along the circumferential direction of the substrate. In this case, a driving means such as a motor can be arranged so that the stage 11 for the substrate rotates in a horizontal plane, and the second irradiation position controlling means 55 can be connected to the driving means.

When the second irradiation position control means 55 moves the transmission region formed on the first surface of the substrate, the transmission region is imaged by the first imaging means 14, and the images captured by the transmission region are stitched together. In addition, it is preferable that an image of the portion to be inspected, for example, an image of the entire first surface of the substrate can be formed. Therefore, for example, after forming a transmission region at an arbitrary end of the first surface 12A of the substrate 12, the transmission region is set along a direction orthogonal to the longitudinal direction of the transmission region. It is efficient and without gaps to move the straight line passing through the opposite side of the first end, that is, the first end and the center of the substrate, to the second end orthogonal to the end of the substrate. It is preferable because it can image.

When the transmission region is moved by the second irradiation position control means 55, for example, every time the transmission region is moved by a certain amount, the transmission region can be imaged by the first imaging means 14 and joined by the first image processing means 16. Then, it is preferable to form an image of a portion to be inspected, for example, an image of the entire first surface of the substrate by joining the images of a plurality of transmission regions captured by the first imaging means 14. Therefore, after the nth transmission region is imaged by the second imaging means, the distance to move the transmission region by the second irradiation position control means before the n + 1th transmission region is imaged, and the width of the images to be stitched, that is, It is preferable to move the transparent region so that the width of the transparent region matches.
(Light source control means)
However, when the first light source 13 and the second light source 53 are turned on at the same time, the light from the first light source 13 and the light from the second light source 53 enter the first imaging means 14 at the same time, and the above-mentioned imaging region In addition, there is a possibility that the above-mentioned transmission region cannot be imaged to the extent that color unevenness or unevenness can be detected.

Therefore, it is preferable that the substrate inspection device 50 of the present embodiment further includes a light source control means 531 that controls light emission of the first light source and the second light source. The control method of the light source control means 531 is not particularly limited, but for example, it is preferable that the first light source 13 and the second light source 53 are turned on alternately. Then, while the first light source 13 is on, the second light source 53 is turned off, and the first imaging means 14 can take an image of an imaging region on the first surface of the substrate 12. While the second light source 53 is lit, the first light source 13 is turned off, and the first imaging means 14 can image a transmission region on the first surface of the substrate 12.

Then, for example, the first image processing means 16 cuts out, for example, a strip-shaped image corresponding to the imaging region from the image captured by the first imaging means 14, arranges them along the moving direction of the imaging region, and connects them. By combining, an image of the entire first surface of the substrate can be formed. Further, from the image captured by the first imaging means 14, for example, a strip-shaped image corresponding to the transmission region is cut out as needed, arranged along the moving direction of the transmission region, and joined together to form the first substrate. An image of the entire surface can also be formed. At this time, the contrast in each image can be corrected as needed.

When a moving image is captured by the first imaging means 14, the first image processing means 16 can also extract a plurality of still images in the imaging region and the transmission region at a predetermined timing.

Then, the image created by the first image processing means 16 can be output to the first output means 19, and color unevenness and unevenness of the substrate can be detected from the obtained image.

Here, a configuration example in which the image captured by the first image processing means 14 is processed by the first image processing means 16 described above has been described, but the present invention is not limited to this form, and for example, in addition to the first image processing means 16. , A second image processing means or the like may be provided to process the image captured by a plurality of image processing means.

Further, for example, it is possible to superimpose an image obtained by connecting the imaging regions and an image obtained by connecting the transmission regions so that the positions of the color unevenness and the unevenness can be compared and confirmed.

Further, the first image processing means 16 can also three-dimensionally collect the images captured by the first imaging means 14 and handle them as image volume data. Then, the first image processing means 16 can perform volume rendering processing on the image volume data on the surface of the substrate obtained by the first imaging means 14. Specifically, for example, the first image processing means 16 creates (renders) an isosurface image with the brightness values of the imaging region and the transmission region for the image volume data, thereby covering the entire surface of the substrate. Images in the imaging region and the transmission region can be extracted. 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 target imaging region and transmission region can be extracted regardless of the number of photographs, and color unevenness and unevenness can be detected more easily.

By treating the obtained image of the substrate surface as image volume data in the first image processing means 16, the brightness and the like are set according to the color unevenness to be detected, the size of the unevenness, and the like, and the image volume data of the substrate surface. Can be divided and the isosurface can be extracted.

According to the substrate inspection apparatus of the present embodiment described above, not only color unevenness on the substrate surface but also irregularities on the substrate surface can be easily detected by a simple apparatus configuration including a light source, an imaging means, and a stage for the substrate. Will be possible.

Further, in the substrate inspection device of the present embodiment, a light source that emits linear light is sufficient, and it is not necessary to use, for example, a large flat plate-shaped light source. Therefore, the entire substrate inspection device can be miniaturized, and the cost can be suppressed.

Further, according to the substrate inspection device of the present embodiment, since the unevenness of the substrate surface is detected by using the transmitted light, the unevenness on the back surface side opposite to the surface to be imaged at the time of inspection is also detected. be able to. Therefore, it is possible to efficiently inspect the unevenness of the substrate surface on both sides of the substrate.
[Board inspection method]
(1) First Embodiment 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 step of irradiating a first surface side of a substrate installed on a substrate stage with linear light from a first light source.
Of the first surface of the substrate, an imaging region that is a region other than the bright region along the longitudinal direction of the bright region, which is a region that reflects linear light emitted from the first light source, is captured by the first imaging means. Imaging process for imaging.

The first irradiation position moving step of changing the position of the bright region.
A repeating step in which the imaging step and the first irradiation position moving step are repeatedly performed.
A first image processing step of processing an image obtained in the imaging step.
Hereinafter, each step will be described.
(1st light irradiation step)
In the first light irradiation step, the surface side of the substrate installed on the substrate stage can be irradiated with linear light from the first light source.

In the first light irradiation step, the first light source does not need to directly irradiate the first surface of the substrate, and may irradiate the vicinity of the first surface of the substrate with light. However, the first surface of the substrate may be directly irradiated with light.

Since the first light source and the shape of the linear light have already been described, detailed description thereof will be omitted. However, as the first light source, a means capable of irradiating the linear light can be used as described above. The configuration is not particularly limited. However, particularly from the viewpoint of improving the efficiency of inspection, it is preferable that the first light source can irradiate a plurality of linear lights parallel to each other on the first surface side of the substrate. In this case, it is preferable to adjust the interval between the plurality of linear lights so that a dark region is formed between the plurality of bright regions that reflect the plurality of irradiated linear lights.

In the first irradiation position moving step described later, by moving the position of the bright region, the imaging region to be imaged by the first imaging means is moved, and the inspection is performed when the images captured in the imaging region are stitched together. It is preferable that an image of a portion, for example, an image of the entire surface of the substrate can be formed. Therefore, for example, in the first light irradiation step, it is preferable to first irradiate light from a light source so that a bright region can be formed at or near the first end, which is an arbitrary end on the surface of the substrate. Then, in the first irradiation position moving step described later, the bright region is set to the end portion opposite to the first end portion, that is, the first end portion along the direction orthogonal to the longitudinal direction of the bright region. It is preferable to move the straight line passing through the center of the substrate to the second end orthogonal to the end of the substrate because it is efficient and the surface of the substrate can be imaged without gaps.
(Imaging process)
In the imaging step, an imaging region is imaged along the longitudinal direction of the bright region that reflects the linear light emitted from the first light source and is a region other than the bright region on the surface of the substrate installed on the substrate stage. can do. In the imaging step, at least the region including the imaging region may be photographed, and the periphery of the imaging region may also be imaged. When the area around the 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. 2, the description thereof will be omitted here.

The image captured in the 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 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 first image processing step, the entire surface of the substrate including the imaging region may be imaged in the imaging step.

As described above, in the imaging step, for example, the imaging region 22 other than the bright region 21A may be imaged along the longitudinal direction of the bright region 21A, and the necessary image may be linear depending on the shape of the bright region and the like. It becomes a band-shaped image. Therefore, a line scan camera can also be used as the first imaging means.

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, the bright region on the surface of the substrate that reflects the linear light and the bright region In the vicinity of the boundary with the adjacent dark region, the contrast of the unevenness on the substrate surface is increased. 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. An image that clarifies is obtained.

Therefore, when it is necessary to inspect the unevenness of the first surface 12A of the substrate 12, in the imaging step, for example, the unevenness detection imaging region including the bright region 21A and the dark region 21B adjacent to the bright region 21A. One or more regions selected from 23A and 23B can also be imaged by the first imaging means 14. The unevenness detection imaging region may be imaged by an imaging means provided separately from the first imaging means 14. In addition, the unevenness detection imaging region can be imaged in a process different from the imaging process.
(First irradiation position moving step)
In the first irradiation position moving step, the position of the bright region can be moved. For example, as described above, the position of the bright region can be moved by the first irradiation position control means.

For example, as described above, at least one of the substrate stage 11 on which the substrate is installed and the first light source 13 can be moved.

In the first irradiation position moving 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 first imaging means and the like.

The continuous movement of the bright region means, for example, the continuous movement of the bright region without stopping, including the repetitive steps described later. In this case, in the imaging step in the repetitive process described later, the imaging region can be imaged at an arbitrary timing and interval.

Further, when the bright region is intermittently moved, the first irradiation position moving step and the imaging step can be alternately performed in the repeating step described later. That is, in the first irradiation position moving step, the bright region can be moved by a certain distance and stopped, and then the imaging step can be performed, and after the first irradiation position moving step is performed again, the imaging step can be carried out.

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

When moving the bright region in the first irradiation position moving step, for example, an imaging step can be performed every time the bright region is moved by a certain amount, the imaging region can be imaged, and the images can be joined in the first image processing step described later. .. 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 the images of a plurality of imaging regions captured in the imaging step. Therefore, in the first irradiation position moving step, after the imaging region is imaged in the nth imaging step, the distance to move the bright region until the imaging region is imaged in the n + 1th imaging step and the width of the images to be stitched together. That is, it is preferable to move the bright region so as to match the width of the imaging region.
(Repeat process)
In the repeating step, the imaging step and the first irradiation position moving step can be repeatedly performed. As a result, images of a plurality of imaging regions can be acquired along the moving direction of the bright region.

As described above, in the substrate inspection method of the present embodiment, by moving the bright region formed on the first surface side of the substrate, the imaging region to be imaged by the first imaging means is moved, and the imaging region is imaged. It is preferable that an image of a portion to be inspected when the combined images are stitched together, for example, an image of the entire surface of the substrate can be formed. Therefore, in the repeating step, when the images of the plurality of imaging regions obtained are stitched together, it is preferable to carry out the process so as to obtain an image of a portion to be inspected, for example, an image of the entire surface of the substrate.

Since the imaging step and the first irradiation position moving step can be carried out in the repeating step according to the procedure described above, the description thereof will be omitted here.
(First image processing step)
In the first image processing step, the image obtained in the imaging step can be processed.

Specifically, for example, the image captured in the imaging step and the imaging step in the repeating process is processed into a linear shape (strip shape) as shown in the imaging region 22 shown in FIG. 2 as necessary, and the image is processed in the moving direction of the bright region. By arranging them along and joining them together, an image of the entire surface of the substrate can be obtained. 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 first imaging means 14 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 imaging step, a plurality of still images in the imaging region at a predetermined timing can be extracted in the first image processing step.

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

In the first image processing step, for example, AI can be used to detect and notify the 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 can be configured so that a portion of the formed image in which color unevenness occurs can be detected and notified by a preset threshold value such as chromaticity or lightness.

The image processing in the first image processing step is not limited to the above method, and for example, images captured in the imaging step and the imaging step in the repeating 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 imaging step and the imaging step in the repeating step. In the first image processing step, specifically, for example, by creating (rendering) an isosurface image with the brightness value of the imaging region for the image volume data, the image of the imaging 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 imaging 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 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.

As described above, when the imaging region for unevenness detection is also imaged, in the first image processing step, for example, a strip-shaped image corresponding to the imaging region for unevenness detection described above is cut out as necessary, and a bright region is formed. It is also possible to form an image of the entire surface of the substrate by arranging and joining them along the moving direction of. At this time, it is also possible to correct the contrast and the like in the formed image as needed.

By the first image processing step, for example, an image of the entire surface of the substrate can be acquired, and the unevenness of the surface of the substrate can be visually confirmed from the contrast with other parts.

Therefore, the unevenness on the surface of the substrate can be detected by outputting the image obtained in the first image processing step to the output device and visually or performing image processing.

Further, for example, in the first image processing step, for example, AI can be used to detect and notify the concave portion or the convex portion of the substrate surface from the image of the substrate surface obtained as described above. ..

In the first 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 imaging step and the imaging step in the repeating step. In the first image processing step, specifically, for example, for image volume data, an isosurface image with a brightness value at the boundary between a bright region and a dark region is created (rendered) over the entire surface of the substrate. Therefore, the image pickup area for detecting unevenness, which is the boundary between the bright area and the dark area, can be extracted. In this case, even if the light source, for example, the fluorescent lamp is slanted when taking an image, or the position of the light source is deviated for each photograph, the boundary surface is the same. Regardless of the number of sheets, the boundary between the bright region and the dark region can be taken out, and the concave portion and the convex portion 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 according to the size of the unevenness to be detected, and the image volume data of the substrate surface. Can be divided and the isosurface can be extracted.

The substrate inspection method of the present embodiment may further include any other steps.

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 skeleton of the inspection device 10 for the substrate is provided with an inclination correction means for adjusting the horizontality, and the horizontality is automatically or manually adjusted. Can be adjusted.

According to the substrate inspection method of the present embodiment described above, it is possible to easily detect color unevenness on the substrate surface by a simple apparatus configuration including a light source, an imaging means, and a substrate stage.

Further, in the substrate inspection method of the present embodiment, it is sufficient that the light source is a light source that emits linear light, and it is not necessary to use, for example, a large flat plate-shaped light source. Therefore, the entire inspection device for the substrate to be used can be miniaturized, and the cost can be suppressed.
(2) Second Embodiment The substrate inspection method according to the second embodiment may further include the following steps in addition to the substrate inspection method described in the first embodiment.

A transmission region imaging step in which a transmission region, which is a region through which linear light emitted from a first light source is transmitted, is imaged by a second imaging means among a second surface located on the opposite side of the first surface of the substrate. ..

A second image processing step of processing the image obtained in the transmission region imaging step.

Then, in the repeating step, the imaging step, the transmission region imaging step, and the first irradiation position moving step can be repeatedly performed.

The substrate inspection method according to the second embodiment can be carried out by using the substrate inspection device 30 shown in FIG. Hereinafter, steps not described in the first embodiment will be described.
(Transmission area imaging process)
In the transmission region imaging step, the linear light emitted from the first light source 13 was transmitted from the second surface 12B located on the opposite side of the first surface 12A of the substrate 12 installed on the substrate stage 11. The transmission region, which is a region, can be imaged by the second imaging means 34.

In the transmission region imaging step, at least the region including the 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 transmission region 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 transparent 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 second image processing step, the entire surface of the substrate including the transmission region may be imaged in the second image processing step.

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

Specifically, the image captured in the transmission region imaging step in the transmission region imaging step and the transmission region imaging step in the repeating step is processed into a linear shape (strip shape) like the transmission region 41A shown in FIG. 4 as necessary, and the transmission region is formed. By arranging them along the moving direction and joining them together, an entire image of the substrate surface can be obtained. At this time, the contrast in the image can be corrected as needed.

When a line scan camera is used as the second imaging means 34 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 transmission region imaging step, a plurality of still images in the transmission region can be extracted at a predetermined timing in the second image processing step.

Then, the image obtained in the second image processing step is output to the second output means 39, and the unevenness on the surface of the substrate can be detected by visual inspection or image processing. Since transmitted light is used in the substrate inspection method of the present embodiment, not only the unevenness contained in the first surface 12A of the substrate but also the unevenness contained in the second surface 12B is obtained as an image. It can also be detected from.

Further, in the second image processing step, for example, AI can be used to detect and notify the concave portion or the convex portion of the substrate surface from the image of the substrate surface obtained as described above.

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

Then, in the second image processing step, volume rendering processing can also be performed on the image volume data on the surface of the substrate obtained in the transmission region imaging step and the repeating 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.

For example, in the second image processing step, the image obtained by joining the imaging regions obtained by the first image processing step described in the first embodiment and the transmission region obtained by the second image processing step are joined together. It is also possible to superimpose the images so that the positions of the color unevenness and the unevenness can be compared and confirmed.
(Repeat process)
In the repeating step, the imaging step, the transmission region imaging step, and the first irradiation position moving step can be repeatedly performed. By repeatedly performing the first irradiation position moving step, the bright region, the imaging region, and the transmission region can be moved. Then, by repeatedly performing the imaging step and the transmission region imaging step, it is possible to acquire images of a plurality of imaging regions and transmission regions along the moving directions of the bright region and the transmission region.

In the substrate inspection method of the present embodiment, by moving the bright region formed on the first surface of the substrate, the imaging region to be imaged by the first imaging means is moved, and the images captured in the imaging region are stitched together. In some cases, it is preferable to be able to form an image of the portion to be inspected, for example, an image of the entire surface of the substrate. Therefore, in the repeating step, when the images of the plurality of imaging regions obtained are stitched together, it is preferable to carry out the process so as to obtain an image of a portion to be inspected, for example, an image of the entire surface of the substrate.

Further, the transmission region formed on the second surface of the substrate is moved, and the region to be imaged by the second imaging means is moved. Then, it is preferable that an image of a portion to be inspected when the images of the transmission region captured by the second imaging means are joined, for example, an image of the entire surface of the substrate can be formed. Therefore, in the repeating step, when the images of the plurality of transparent regions obtained are stitched together, it is preferable to carry out the process so as to obtain an image of a portion to be inspected, for example, an image of the entire surface of the substrate.

Since the imaging step, the transmission region imaging step, and the first irradiation position moving step can be performed in the repeating step according to the procedure described above, the description thereof will be omitted here.
(3) Third Embodiment The substrate inspection method according to the second embodiment may further include the following steps in addition to the substrate inspection method described in the first embodiment.

A second light irradiation step of irradiating a second surface located on the opposite side of the first surface of the substrate with linear light from the second light source.
A second irradiation position moving step of changing the position of a transmission region, which is a region through which linear light emitted from a second light source is transmitted, on the first surface of the substrate.
A transmission region imaging step in which a transmission region of the first surface of a substrate is imaged by a first imaging means.

A second image processing step of processing the image obtained in the transmission region imaging step.
Then, in the repeating step, the imaging step, the transmission region imaging step, the first irradiation position moving step, and the second irradiation position moving step can be repeatedly performed.

The substrate inspection method according to the third embodiment can be carried out by using the substrate inspection device 50 shown in FIG. Hereinafter, steps not described in the first embodiment will be described.
(Second light irradiation step)
In the second light irradiation step, the second surface of the substrate installed on the substrate stage can be irradiated with linear light from the second light source.

Since the details of the second light source and the shape of the linear light have already been described, detailed description thereof will be omitted. However, as the second light source, a means capable of irradiating the linear light can be used as described above. The configuration is not particularly limited. However, particularly from the viewpoint of improving the efficiency of inspection, it is preferable that the second light source can irradiate the second surface of the substrate with a plurality of linear lights parallel to each other. In this case, a plurality of linear lights are transmitted so that a plurality of linear lights irradiated to the substrate are transmitted and a dark region is formed between the plurality of transmitted regions formed on the first surface side. It is preferable to adjust the light interval.

In the second irradiation position moving step described later, an image of a portion to be inspected when the transmission region formed on the first surface of the substrate is moved and the images obtained by capturing the transmission region are joined, for example, the entire surface of the substrate. It is preferable that the image of the above can be formed. Therefore, for example, in the second light irradiation step, it is preferable to first irradiate light from the second light source so that a transmission region can be formed on the first end side, which is an arbitrary end on the surface of the substrate. Then, in the second irradiation position moving step described later, the transmission region is set to the end portion opposite to the first end portion, that is, the first end portion along the direction orthogonal to the longitudinal direction of the transmission region. It is preferable to move the straight line passing through the center of the substrate to the second end orthogonal to the end of the substrate because it is efficient and the surface of the substrate can be imaged without gaps.

When the first light source 13 and the second light source 53 are turned on at the same time, the light from the first light source 13 and the light from the second light source 53 enter the first imaging means 14 at the same time, as described above. There is a possibility that the imaging region and the transmission region described above cannot be imaged to the extent that color unevenness or unevenness can be detected.

Therefore, it is preferable that, for example, the first light source 13 and the second light source 53 are alternately turned on by the light source control means 531 that controls the light emission of the first light source and the second light source. Therefore, it is preferable that the first light irradiation step and the second light irradiation step are alternately performed.
(Second irradiation position moving step)
In the second irradiation position moving step, the position of the transmission region can be moved. For example, as described above, the position of the transmission region can be moved by the second irradiation position control means.

For example, as described above, at least one of the substrate stage 11 on which the substrate is installed and the second light source 53 can be moved.

In the second irradiation position moving step, the transmission region may be moved continuously or intermittently. For example, the moving condition of the transmission region can be selected according to the performance of the first imaging means and the like.

The continuous movement of the transmission region means, for example, the continuous movement of the transmission region without stopping, including the repetitive steps described later. In this case, in the transmission region imaging step in the repeating step described later, the transmission region can be imaged at arbitrary timings and intervals.

Further, when the transmission region is intermittently moved, the second irradiation position movement step and the transmission region imaging step can be alternately performed in the repeating step described later. That is, in the second irradiation position moving step, the transmission region can be moved by a certain distance and stopped, then the transmission region imaging step can be performed, and after the second irradiation position moving step is performed again, the transmission region imaging step can be performed.

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

When moving the transmission region in the second irradiation position moving step, for example, the transmission region 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 be done. 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 the transmission region captured in the transmission region imaging step. Therefore, in the second irradiation position moving step, after the transmission region is imaged in the nth transmission region imaging step, the distance to move the transmission region until the transmission region is imaged in the n + 1th transmission region imaging step is connected. It is preferable to move the bright region so that the width of the images to be combined, that is, the width of the transparent region matches.
(Transmission area imaging process)
In the transmission region imaging step, on the surface of the substrate installed on the substrate stage, a transmission region through which linear light emitted from the second light source is transmitted can be imaged. In the transmission region imaging step, at least the region including the 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 transmission region is the same as the transmission region described with reference to FIG. 3 except that the surface of the formed substrate is different, the description thereof will be omitted here.

The image captured in the transmission region 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 transparent 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 second image processing step, the entire surface of the substrate including the transmission region may be imaged in the transmission region imaging step.
(Second image processing process)
In the second image processing step, the image obtained in the transmission region imaging step can be processed.

Specifically, the images captured in the transmission region imaging step and the transmission region imaging step in the repeating process are processed into a linear shape (strip shape) as necessary, arranged along the moving direction of the transmission region, and stitched together. Therefore, the entire image of the substrate surface can be obtained. At this time, the contrast in the image can be corrected as needed.

When a line scan camera is used as the first imaging means 14 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 transmission region imaging step, a plurality of still images in the transmission region can be extracted at a predetermined timing in the second image processing step.

Then, the image obtained in the second image processing step is output to the first output means 19, and the unevenness on the surface of the substrate can be detected by visual inspection or image processing. Since transmitted light is used in the substrate inspection method of the present embodiment, not only the unevenness contained in the first surface 12A of the substrate but also the unevenness contained in the second surface 12B is obtained as an image. It can also be detected from.

Further, in the second image processing step, for example, AI can be used to detect and notify the concave portion or the convex portion of the substrate surface from the image of the substrate surface obtained as described above.

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

Then, in the second image processing step, volume rendering processing can also be performed on the image volume data on the surface of the substrate obtained in the transmission region imaging step and the repeating 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.

For example, in the second image processing step, the image obtained by joining the imaging regions obtained by the first image processing step described in the first embodiment and the transmission region obtained by the second image processing step are joined together. It is also possible to superimpose the images so that the positions of the color unevenness and the unevenness can be compared and confirmed.
(Repeat process)
In the repeating step, the imaging step, the transmission region imaging step, the first irradiation position moving step, and the second irradiation position moving step can be repeatedly performed. As a result, it is possible to acquire images of a plurality of imaging regions and transparent regions along the moving directions of the bright region and the transparent region.

As described above, in the substrate inspection method of the present embodiment, by moving the bright region formed on the first surface of the substrate, the imaging region to be imaged by the first imaging means is moved, and the imaging region is imaged. It is preferable that an image of a portion to be inspected when the images are stitched together, for example, an image of the entire surface of the substrate can be formed. Therefore, in the repeating step, when the images of the plurality of imaging regions obtained are stitched together, it is preferable to carry out the process so as to obtain an image of a portion to be inspected, for example, an image of the entire surface of the substrate.

Further, the transmission region formed on the first surface of the substrate is moved, and the region to be imaged by the first imaging means is moved. Then, it is preferable that an image of a portion to be inspected when the images of the transmission region captured by the first imaging means are joined, for example, an image of the entire surface of the substrate can be formed. Therefore, in the repeating step, when the images of the plurality of transparent regions obtained are stitched together, it is preferable to carry out the process so as to obtain an image of a portion to be inspected, for example, an image of the entire surface of the substrate.

In the repeating step, the imaging step, the transmission region imaging step, the first irradiation position moving step, and the second irradiation position moving step can be performed according to the procedure described above, and thus the description thereof will be omitted here.

10, 30, 50 Substrate inspection device 11 Substrate stage 12 Substrate 12A First surface 12B Second surface 13 First light source 14 First image pickup means 15 First irradiation position control means 16 First image processing means 22 Imaging area 34 Second image pickup means 36 Second image processing means 41A Transmission region 53 Second light source 55 Second irradiation position control means 531 Light source control means

Claims (14)

The board stage on which the board is installed and
A first light source that irradiates the first surface side of the substrate installed on the substrate stage with linear light, and
Of the first surface of the substrate, an imaging region that is a region other than the bright region along the longitudinal direction of the bright region, which is a region that reflects the linear light emitted from the first light source. The first imaging means for imaging and
The first irradiation position control means for changing the position of the bright region and
A substrate inspection apparatus having a first image processing means for processing an image obtained by the first imaging means. A second imaging means for imaging a transmission region, which is a region that transmits the linear light emitted from the first light source, among the second surfaces located on the opposite side of the first surface of the substrate. ,
The substrate inspection apparatus according to claim 1, further comprising a second image processing means for processing an image obtained by the second imaging means. A second light source that irradiates a second surface of the substrate opposite to the first surface with linear light.
A second irradiation position control means for changing the position of a transmission region, which is a region through which the linear light emitted from the second light source is transmitted, on the first surface of the substrate.
Further, the first light source and the light source control means for controlling the light emission of the second light source are provided.
The substrate inspection apparatus according to claim 1, wherein the first imaging means also performs imaging of the transmission region of the first surface of the substrate. The substrate inspection apparatus according to any one of claims 1 to 3, wherein the first 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 substrate inspection apparatus according to any one of claims 1 to 5, wherein the first light source can irradiate a plurality of linear lights parallel to each other. The first image processing means creates an isosurface image with a brightness value of the imaging region for the image volume data of the first surface of the substrate obtained by the first imaging means. The substrate inspection apparatus according to any one of claims 1 to 6, wherein the imaging region is taken out. The first light irradiation step of irradiating the first surface side of the substrate installed on the substrate stage with linear light from the first light source, and
Of the first surface of the substrate, an imaging region that is a region other than the bright region along the longitudinal direction of the bright region, which is a region that reflects the linear light emitted from the first light source. The imaging process of imaging by the first imaging means and
The first irradiation position moving step of changing the position of the bright region and
A repetitive step of repeatedly performing the imaging step and the first irradiation position moving step, and
A method for inspecting a substrate, comprising a first image processing step of processing an image obtained in the imaging step. Of the second surface of the substrate opposite to the first surface, the transmission region, which is the region through which the linear light emitted from the first light source is transmitted, is imaged by the second imaging means. Transmission area imaging process and
It further includes a second image processing step of processing the image obtained in the transmission region imaging step.
The substrate inspection method according to claim 8, wherein in the repeating step, the imaging step, the transmission region imaging step, and the first irradiation position moving step are repeatedly performed. A second light irradiation step of irradiating a second surface of the substrate opposite to the first surface with linear light from a second light source.
A second irradiation position moving step of changing the position of the transmission region, which is a region through which the linear light emitted from the second light source, is transmitted on the first surface of the substrate.
A transmission region imaging step of imaging the transmission region of the first surface of the substrate by the first imaging means.
It further includes a second image processing step of processing the image obtained in the transmission region imaging step.
The substrate inspection method according to claim 8, wherein in the repeating step, the imaging step, the transmission region imaging step, the first irradiation position moving step, and the second irradiation position moving step are repeatedly performed. The substrate inspection method according to any one of claims 8 to 10, wherein the first imaging means is a line scan camera. The method for inspecting a substrate according to any one of claims 8 to 11, further comprising a tilt correction step for leveling the substrate. The first light source according to any one of claims 8 to 12, wherein the first light source can irradiate a plurality of linear lights parallel to each other on the first surface side of the substrate. How to inspect the board. In the first image processing step, an isosurface image with a brightness value of the imaging region is created for the image volume data of the first surface of the substrate obtained in the imaging step and the repeating step. The substrate inspection method according to any one of claims 8 to 13, wherein the imaging region is taken out.

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