JP2021124299A - Device and method for inspecting substrate - Google Patents

Abstract

To provide an inspection device for a substrate that can detect recesses or protrusions of the surface of the substrate or can detect unevenness of color on the surface of the substrate.SOLUTION: The inspection device for a substrate includes: a substrate stage; a first light source; a first mirror; first mirror moving means connected to the first mirror, the first mirror moving means being capable of displacing the first mirror between a first position and a second position; imaging means for taking an image of a first surface side of the substrate placed on the substrate stage; and image processing means for processing the image taken by the imaging means, the first mirror moving means displacing the first mirror from the first position to the second position so that a linear light which was emitted from the first light source and was reflected by the surface of the first mirror can be scanned on the first surface of the substrate.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, the color unevenness of the substrate surface that is caused by the unevenness of the substrate surface, the non-uniform composition of the surface of the substrate after the reaction process such as heat treatment, and the non-uniform thickness of the substrate can be detected. An inspection device was sought.

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

According to one aspect of the present invention in order to solve the above problems.
Board stage and
With the first light source
The first mirror and
A first mirror moving means that is connected to the first mirror and can displace the first mirror between the first position and the second position.
An imaging means for imaging the first surface side of the substrate arranged on the substrate stage, and
It is provided with an image processing means for processing an image obtained by the imaging means.
The first mirror moving means displaces the first mirror from the first position to the second position, so that linear light emitted from the first light source and reflected on the surface of the first mirror. To provide a substrate inspection apparatus capable of scanning on the first surface of the substrate.

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

FIG. 5 is a cross-sectional view of the inspection device according to the embodiment of the present invention when the first mirror is located at the first position. FIG. 5 is a cross-sectional view of the inspection device according to the embodiment of the present invention when the first mirror is located at the second position. Explanatory drawing of the imaging area. Explanatory drawing of the transparent area.

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

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

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

1 and 2 show cross-sectional views of the substrate inspection device 10 according to the first embodiment in a plane passing through the center of the substrate 16. FIG. 1 shows a state in which the first mirror 13 included in the substrate inspection device 10 according to the first embodiment is in the first position 13A, and FIG. 2 shows a state in which the first mirror 13 is in the second position 13B. There is.

The substrate inspection device 10 of the present embodiment includes a substrate stage 11, a first light source 12, a first mirror 13, a first mirror moving means 14, an imaging means 15, and an image processing means 18. Can be done.
The first mirror moving means 14 is connected to the first mirror 13, and the first mirror 13 can be displaced between the first position 13A and the second position 13B.
The imaging means 15 can image the first surface 16A side of the substrate 16 arranged on the substrate stage 11.
The image processing means 18 can process the image obtained by the imaging means 15.
The first mirror moving means 14 is a linear light emitted from the first light source 12 and reflected on the surface of the first mirror 13 by displacing the first mirror 13 from the first position 13A to the second position 13B. Can be scanned on the first surface 16A of the substrate 16.

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.

The substrate stage 11 may be provided with, for example, a means for correcting the inclination of the substrate 16 installed on the substrate stage 11 to make it horizontal, for example, an inclination correction means described later.

The type of substrate to be inspected by the substrate inspection device of the present embodiment is not particularly limited, and various substrates can be used. Further, the shape of the substrate is not particularly limited, but for example, a disk-shaped substrate can be used.
(First light source)
Regarding the first light source 12, the specific configuration such as the type of the light source is not particularly limited. The first light source 12 is the first surface of the substrate 16 installed on the stage 11 for the substrate so that the first surface 16A side of the substrate 16 can be irradiated with linear light via the first mirror 13 described later. It can be arranged on the 16A side.

The linear light may have a linear shape on the first surface 16A of the irradiated substrate 16, and the specific shape thereof is not particularly limited, but includes, for example, linear light and a bent portion. It can be any light selected from linear light, wavy light, and the like. 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 from the viewpoint of efficient inspection, for example, the light is irradiated over the entire width direction of the substrate to be inspected through the first mirror, and the light is bright. The length can be selected so that the region can be formed.

The light emitting means of the light source is not particularly limited as long as it can form linear light, 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 16A of the substrate 16 to be evaluated and the reflected image can be imaged by the imaging means 15. 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, when inspecting the unevenness of the substrate surface, linear light emitted from the first light source 12 and reflected by the surface of the first mirror 13 (hereinafter referred to as “1st mirror 13”) is emitted from the substrate surface. The imaging means 15 captures a first imaging region that simultaneously includes a bright region and a dark region adjacent to the bright region along the longitudinal direction of the bright region, which is a region that reflects (simply referred to as “linear light”). can. Then, while changing the position of the bright region, the first imaging region is photographed, and the image of the portion to be inspected when the obtained images of the first imaging region are joined, for example, the image of the entire substrate surface is obtained. It is preferable to carry out repeatedly until it is obtained.

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

Therefore, from the viewpoint of improving the efficiency of 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 12 can simultaneously irradiate a plurality of linear lights parallel to each other. Therefore, it is preferable that the first light source 12 is configured so that a plurality of linear lights parallel to each other can be emitted to the surface of the substrate through the first mirror 13. 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 12 can be fixed to a housing 17 installed in the inspection device 10 of the substrate. However, the present invention is not limited to this, and the first light source 12 can be fixed by using a tripod or the like separately from other members.
(1st mirror)
The first mirror 13 can be configured to reflect the light emitted from the first light source 12 and irradiate the first surface 16A side of the substrate 16.

The first mirror 13 may reflect the light emitted from the first light source 12, and its material, shape, and the like are not particularly limited.

For example, the material of the first mirror 13 can be selected according to the wavelength of the light emitted from the first light source 12 and the like so that the light emitted from the first light source 12 can be reflected.

Further, the first mirror 13 can be displaced (moved) from the first position 13A shown in FIG. 1 to the second position 13B shown in FIG. 2 by the first mirror moving means 14 described later. By displacing the first mirror 13 from the first position 13A to the second position 13B, the linear light emitted from the first light source 12 and reflected on the surface of the first mirror 13 is emitted from the first of the substrate 16. Can be scanned on the surface 16A of. Therefore, the shape of the first mirror 13 can be selected according to the mode of movement by the first mirror moving means 14.
(First mirror moving means)
The first mirror moving means 14 is connected to the first mirror 13 and can displace the first mirror 13 from the first position 13A to the second position 13B.

Although FIG. 1 shows an example in which the first mirror 13 is rotated around the first mirror moving means 14 as a rotation axis, the present invention is not limited to this mode.

In the substrate inspection device 10 of the present embodiment, by displacing the first mirror 13 from the first position 13A to the second position 13B, the first mirror 13 is emitted from the first light source 12 and reflected on the surface of the first mirror 13. It changes the optical path of linear light. Specifically, for example, the optical path L1 shown by the dotted line in FIGS. 1 and 2 is changed as shown by the optical path L2. Thereby, for example, the position where the linear light is irradiated on the first surface 16A side of the substrate 16 can be moved from the irradiation position S1 to the irradiation position S2. That is, linear light can be scanned on the first surface 16A of the substrate 16.

For example, as shown in FIG. 2, when the first mirror 13 is displaced to the second position 13B, the light emitted from the first light source 12 reflected on the surface of the first mirror 13 is emitted from the substrate 16. It may be configured so that it can directly irradiate a place (position) other than the first surface 16A of the above.

The mode in which the linear light is scanned on the first surface 16A of the substrate 16 by the first mirror moving means is not particularly limited. However, for example, it is preferable that an image of the entire surface of the substrate can be formed by connecting the first imaging region and the second imaging region, which will be described later.

Therefore, for example, a bright region, which is a region for reflecting linear light, is formed by irradiating linear light at or near the first end, which is an arbitrary end of the first surface of the substrate. Later, a straight line passing through the bright region along the direction orthogonal to the longitudinal direction of the bright region, opposite to the first end portion, that is, the first end portion and the center of the substrate is the edge portion of the substrate. It is preferable to scan so as to move to the second orthogonal ends because the substrate surface can be imaged efficiently and without gaps.
(Imaging means)
The imaging means 15 can image the first surface 16A side of the substrate 16 arranged on the substrate stage 11.

The specific area to be imaged by the imaging means 15 is not particularly limited, and the area to be imaged can be selected depending on the object to be inspected. Specifically, a predetermined range can be imaged according to the case of inspecting the unevenness of the substrate surface and the case of inspecting the color unevenness. According to the substrate inspection apparatus of the present embodiment, both the unevenness of the surface of the substrate and the color unevenness can be inspected at the same time. Therefore, the first imaging region and the second imaging region described below can be imaged at the same time. In the following description, the first imaging region and the second imaging region may be collectively referred to as an imaging region.
(A) When inspecting the unevenness of the first surface of the substrate According to the study of the inventor of the present invention, when the first surface of the substrate is irradiated with linear light, the surface of the substrate is linear. In the vicinity of the boundary between the bright region that reflects the light and the dark region adjacent to the bright region, the contrast of the unevenness of the first surface of the substrate is increased. Therefore, when inspecting the unevenness of the first surface of the substrate, linear light is scanned on the first surface 16A of the substrate 16 by using the first mirror moving means as described above, and the substrate 16 is inspected. The position of the bright region formed on the first surface 16A of the above can be displaced, and the imaging means 15 can image the vicinity of the boundary between the bright region and the dark region adjacent to the bright region.

Specifically, when inspecting the unevenness of the first surface of the substrate as described above, the imaging means 15 is oriented in the longitudinal direction of the bright region of the first surface 16A of the substrate 16 that reflects linear light. A first imaging region including a bright region along the line and a dark region adjacent to the bright region can be imaged.

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

FIG. 3 shows the first surface 16A of the substrate 16 and shows a state in which one linear light is irradiated and a bright region 31A that reflects the linear light is formed.

By irradiating the first surface 16A of the substrate 16 with linear light from the first light source 12 via the first mirror 13 in this way, the first surface 16A of the substrate 16 is exposed to linear light. A bright region 31A that reflects light is formed. The bright region 31A is a linear (band-shaped) region corresponding to the linear light from the first light source 12.

The region other than the bright region 31A is a dark region 31B that is darker than the bright region 31A because the degree of reflection of light from the first light source is low or the light is not reflected.

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

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

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

When the captured images are collected three-dimensionally and handled as image volume data as described later, the imaging means may image the entire surface of the substrate including the first imaging region.
(B) When inspecting color unevenness on the surface of the substrate According to the study of the inventor of the present invention, when the first surface side of the substrate is irradiated with linear light, the surface of the first surface of the substrate is inspected. By observing a region other than the bright region that reflects linear light, that is, directly irradiates the light, it is possible to easily detect color unevenness on the first surface of the substrate, that is, regions having different colors. Therefore, when inspecting the color unevenness of the first surface of the substrate, linear light is scanned on the first surface 16A of the substrate 16 by using the first mirror moving means as described above, and the substrate 16 is inspected. The position of the bright region formed on the first surface 16A of the light region is displaced, and the imaging means 15 can image a second imaging region that is a region other than the bright region along the longitudinal direction of the bright region.

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

As described above, FIG. 3 shows the first surface 16A of the substrate 16 and shows a state in which linear light is emitted from the first light source 12. By irradiating the first surface 16A of the substrate 16 with linear light from the first light source 12 in this way, the light from the first light source 12 is reflected on the first surface 16A of the substrate 16. Region 31A is formed.

The region other than the bright region 31A of the first surface 16A of the substrate 16 is a dark region 31B that is darker than the bright region 31A because the light from the light source is not directly irradiated. The imaging means 15 is a second imaging region 33 surrounded by a dotted line other than the bright region 31A, that is, in the dark region 31B, at least along the longitudinal direction of the bright region 31A, that is, along the X-axis direction in the drawing. Can be imaged. In this case, at least the region including the second imaging region 33 may be photographed, and the periphery of the second imaging region 33 may also be imaged. When the area around the second imaging region 33 is also imaged, the image of the target second imaging region can be cut out from the captured image by the image processing means described later.

Here, the case where the light from the first light source 12 is directly irradiated to the first surface 16A of the substrate 16 has been described as an example, but when inspecting the color unevenness, the light from the first light source 12 has been described. Does not need to be directly irradiated on the first surface 16A of the substrate 16. For example, the light emitted from the first light source 12 may be applied to a place other than the first surface 16A of the substrate 16 and illuminated by the reflected indirect light.

However, in order to detect color unevenness, it is preferable that the degree of brightness in the second imaging region 33 due to the light from the first light source 12 is uniform. Therefore, as described above, the first surface 16A of the substrate 16 or its vicinity is irradiated with the light from the first light source 12, the second imaging region is set along the longitudinal direction of the bright region, and imaging is performed. Is preferable. Further, the length in the direction perpendicular to the longitudinal direction of the second imaging region is not excessively long so that the degree of brightness in the second imaging region due to the light from the first light source 12 becomes uniform. It is preferable to set the area. The length in the direction perpendicular to the longitudinal direction of the second imaging region referred to here means the length in the Y-axis direction in FIG.

As will be described later, it is also possible to form an image of the entire surface of the substrate by stitching together the images of the second imaging region captured by the image processing means. Then, from the viewpoint of more accurately detecting color unevenness from the image of the entire surface of the formed substrate, it is preferable that the brightness of the image of the entire surface of the formed substrate is uniform. That is, it is preferable that the brightness of the images in the plurality of second imaging regions constituting the image of the entire surface of the substrate is uniform. Therefore, when the position of the bright region 31A formed by irradiating the linear light from the first light source 12 is changed, the distance between the bright region 31A and the second imaging region 33 should be kept constant. Is preferable.

When the images captured as described later are collected three-dimensionally and handled as image volume data, the imaging means 15 covers the entire first surface 16A of the substrate 16 including the first imaging region and the second imaging region. You may take an image.

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

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

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

As shown in FIG. 1, for example, the image pickup means 15 can be fixed to the housing 17 of the inspection device 10 on the substrate. However, the present invention is not limited to this, and the imaging means 15 can be fixed by using a tripod or the like separately from other members.
(Image processing means)
The image processing means 18 can process the image captured by the imaging means 15.

The image processing means 18 is an ASIC (application specific integrated circuit) or the like, and is in charge of processing an image captured by the imaging means 15.

The image processing means 18 cuts out, for example, a strip-shaped image corresponding to the first imaging region or the second imaging region described above according to the inspection target from the image captured by the imaging means 15, and moves the bright region. By arranging and joining them together, an image of the entire surface of the substrate can be formed. At this time, it is also possible to correct the contrast in the image or perform image processing such as binarization processing as necessary.

When the moving image is captured by the imaging means 15, the image processing means 18 can also extract a plurality of still images in the imaging region at a predetermined timing.

Then, the image created by the image processing means 18 can be output to the output means 19, and the unevenness of the substrate surface and the color unevenness can be visually detected from the obtained image due to the difference in contrast in the obtained image. .. It should be noted that the unevenness of the first surface of the substrate can be detected from the image obtained by connecting the first imaging regions described above, and the color unevenness of the first surface of the substrate can be detected from the image obtained by connecting the second imaging regions.

The configuration of the output means 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 image processing means 18 can be provided with, for example, AI (artificial intelligence), and can detect irregularities and color unevenness on the first surface of the substrate from the image of the substrate surface obtained as described above. It can also be configured to notify you. In addition, the image processing means or the like may be configured so that, for example, a preset threshold value such as chromaticity or lightness can be used to detect and notify unevenness or a portion where color unevenness occurs in the formed image. can.

The image processing means 18 can be realized by software in one ASIC, but a part or all of it may be realized by hardware, for example, by providing a plurality of ASICs.

Further, the image processing means 18 can also three-dimensionally collect the images captured by the imaging means 15 and handle them as image volume data. Then, the image processing means 18 can perform volume rendering processing on the image volume data on the surface of the substrate obtained by the imaging means 15. Specifically, for example, the image processing means 18 creates (renders) an isosurface image at the brightness value of the first imaging region or the second imaging region for the image volume data, thereby covering the entire surface of the substrate. , Images in the first imaging region and the second imaging region can be extracted. In this case, even if the 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 first imaging region or second imaging region can be taken out regardless of the number of photographs, and unevenness and color unevenness can be detected more easily.

By treating the obtained image of the substrate surface as image volume data in the image processing means 18, the brightness and the like are set according to the size of unevenness and color unevenness to be detected, and the image volume data of the substrate surface is divided. , The isosurface can be extracted.

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, although the example in which the first light source 12 which is a light source is provided only on the first surface 16A side of the substrate 16 has been shown so far, the present invention is not limited to this. The substrate inspection device 10 of the present embodiment is, for example, a second light source 22, a second mirror 23, and a second mirror moving means on the second surface 16B side located on the opposite side of the first surface 16A of the substrate 16. 24 can be further provided.
The second light source 22 can be arranged on the second surface 16B side located on the opposite side of the first surface 16A of the substrate 16 as described above. The second mirror 23 can also be arranged on the second surface 16B side of the substrate 16.

The second mirror moving means 24 is connected to the second mirror 23 and displaces the second mirror 23 between the third position 23A (see FIG. 1) and the fourth position 23B (see FIG. 2). Can be made to.
In this case, the light source control means 221 for controlling the light emission of the first light source 12 and the second light source 22 can be further provided.
Then, the second mirror moving means 24 displaces the second mirror 23 from the third position 23A to the fourth position 23B, so that the light emitted from the second light source 22 and reflected on the surface of the second mirror 23 is emitted. , Can be scanned on the second surface 16B of the substrate 16.

Color unevenness on the surface of the substrate is caused by, for example, uneven composition of the surface of the substrate, non-uniform thickness, and the like. Then, for example, if a recess or the like is formed on the second surface which is the back surface of the substrate and there is a portion where the thickness of the substrate is not uniform, it may be detected as color unevenness on the first surface side. For this reason, it is more preferable to detect the unevenness of the back surface of the substrate as well, so that it can be confirmed whether the cause is, for example, a recess on the back surface side of the substrate.

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

Hereinafter, each member when the second light source 22 and the like are provided on the second surface 16B side of the substrate 16 will be described.
(Second light source)
The second light source 22 may be configured so as to be able to irradiate the second surface 16B of the substrate 16 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 22 can be arranged on the second surface 16B side of the substrate 16 installed on the substrate stage 11 so that the second surface 16B of the substrate 16 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 from the viewpoint of efficient inspection, light is irradiated and transmitted over the entire width direction of the substrate to be inspected, for example, through a second mirror. The length can be selected so that the 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 16 to be evaluated and can image the light transmitted by the imaging means 15. 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, can be imaged by the imaging means on the first surface of the substrate. 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 22 may be fixed to the housing 17 installed in the inspection device 10 of the substrate as shown in FIGS. 1 and 2, for example. However, the present invention is not limited to this, and the second light source 22 can be fixed by using a tripod or the like separately from other members.
(Second mirror)
The second mirror 23 can be configured to reflect the light emitted from the second light source 22 and irradiate the second surface 16B side of the substrate 16.

The second mirror 23 only needs to be able to reflect the light emitted from the second light source 22, and its material, shape, and the like are not particularly limited.

For example, the material of the second mirror 23 can be selected according to the wavelength of the light emitted from the second light source 22 and the like so that the light emitted from the second light source 22 can be reflected.

Further, the second mirror 23 can be displaced (moved) from the third position 23A shown in FIG. 1 to the fourth position 23B shown in FIG. 2 by the second mirror moving means 24 described later. By displacing the second mirror 23 from the third position 23A to the fourth position 23B, the linear light emitted from the second light source 22 and reflected on the surface of the second mirror 23 is emitted from the second substrate 26. Can be scanned on the second surface 16B of. Therefore, the shape of the second mirror 23 can be selected according to the mode of movement by the second mirror moving means 24.
(Second mirror moving means)
The second mirror moving means 24 is connected to the second mirror 23, and the second mirror 23 can be displaced from the third position 23A to the fourth position 23B.

Although FIG. 1 shows an example in which the second mirror 23 is rotated around the second mirror moving means 24 as a rotation axis, the present invention is not limited to this mode.

In the substrate inspection device 10 of the present embodiment, by displacing the second mirror 23 from the third position 23A to the fourth position 23B, the second mirror 23 is emitted from the second light source 22 and reflected on the surface of the second mirror 23. It changes the optical path of linear light. Specifically, for example, the optical path L3 shown by the dotted line in FIGS. 1 and 2 is changed to the optical path L4. Thereby, for example, the position where the linear light is irradiated on the second surface 16B side of the substrate 16 can be moved from the irradiation position S3 to the irradiation position S4. That is, linear light can be scanned on the second surface 16B of the substrate 16.
(Imaging means)
As the imaging means, the above-mentioned imaging means 15 can be used, or a separate imaging means can be provided to image the transmission region.

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

FIG. 4 shows the first surface 16A side of the substrate 16, which is the side opposite to the first surface 16A of the substrate 16, that is, the back surface is the second surface, and the second surface is from the second light source. It is a surface that is irradiated with linear light. Then, FIG. 4 shows a state in which one linear light is irradiated to the second surface from the second light source, and a transmission region 41A corresponding to this is formed on the first surface 16A.

When the second surface 16B of the substrate 16 is irradiated with linear light from the second light source, a transmission region 41A that transmits the light from the light source is formed on the second surface 16B of the substrate 16. The transmission region 41A is a linear (band-shaped) region corresponding to the linear light from the second 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 16. It is formed.

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

The image captured by the imaging means 15 may be a moving image or a still image. In the case of moving images, for example, a plurality of still images in a transmission region at an arbitrary timing can be extracted and used from the captured images by an image processing means.
(Light source control means)
However, when the first light source 12 and the second light source 22 are turned on at the same time, the light from the first light source 12 and the light from the second light source 22 enter the imaging means 15 at the same time, and the first imaging region described above , There is a possibility that the second imaging region and the transmission region cannot be imaged to the extent that color unevenness or unevenness can be detected.

Therefore, when the second light source 22 is provided on the second surface 16B side of the substrate 16, the substrate inspection device 10 of the present embodiment further includes the first light source and the light source control means 221 for controlling the light emission of the second light source. Is preferable. The control method of the light source control means 221 is not particularly limited, but for example, it is preferable that the first light source 12 and the second light source 22 are turned on alternately. Then, while the first light source 12 is lit, the second light source 22 is turned off, and the imaging means 15 images the first imaging region and the second imaging region on the first surface of the substrate 16. Can be done. While the second light source 22 is on, the first light source 12 is turned off, and the image pickup means 15 can take an image of the transmission region on the first surface of the substrate 16.

Then, for example, the image processing means 18 described above cuts out, for example, a strip-shaped image corresponding to the transmission region from the image captured by the imaging means 15 as necessary, in addition to the operation described above, and moves the transmission region. By arranging them along the direction and joining them together, an image of the entire first surface of the substrate can be formed. At this time, the contrast in each image can be corrected as needed.

When the moving image is captured by the imaging means 15, the image processing means 18 can also extract a plurality of still images in the transmission region at a predetermined timing.

Here, a configuration example in which the image captured by the imaging means 15 is processed by the image processing means 18 described above has been described, but the present invention is not limited to this, and for example, in addition to the image processing means 18, one or two or more are further described. The image processing means and the like may be provided, and the image captured by a plurality of image processing means may be processed.

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

The image processing means 18 can also three-dimensionally collect the images captured by the image pickup means 15 and handle them as image volume data. Then, the image processing means 18 can perform volume rendering processing on the image volume data on the surface of the substrate obtained by the imaging means 15. Specifically, for example, the image processing means 18 creates (renders) an isosurface image with the brightness value of the transmission region for the image volume data, thereby extracting the image of the transmission region over the entire surface of the substrate. be able to. In this case, even if the second 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 brightness value is common, so that the predetermined brightness is obtained. By dividing by the value, the target transparent region can be extracted regardless of the number of photographs, and the unevenness can be detected more easily.

By treating the obtained image of the substrate surface as image volume data in the image processing means 18, the brightness and the like are set according to the size of the unevenness to be detected, the image volume data of the substrate surface is divided, and the isosurfaces are obtained. A surface (isosurface) can be taken out.

By detecting the unevenness of the substrate surface using the transmitted light in this way, the unevenness of the first surface and the second surface of the substrate can be detected together. Therefore, it is possible to efficiently inspect the unevenness of the substrate surface on both sides of the substrate.

According to the substrate inspection apparatus of the present embodiment described above, unevenness on the substrate surface and color unevenness on the substrate surface can be easily detected by a simple apparatus configuration including a light source, an imaging means, and a stage for the substrate. Becomes 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. Furthermore, by moving the first mirror and the second mirror, the substrate can be inspected without moving the light source or the imaging means. Therefore, the entire substrate inspection device can be miniaturized, and the cost can be suppressed.
[Board inspection method]
The substrate inspection method of the present embodiment will be described. The substrate inspection method of the present embodiment can be suitably carried out by using the substrate inspection apparatus described above. Therefore, some of the matters already explained will be omitted.

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

The linear light emitted from the first light source is connected to the first mirror moving means, reflected by the surface of the first mirror arranged at the first position, and reflected on the surface of the first mirror arranged at the first position, and the first surface of the substrate installed on the substrate stage. The first light irradiation start step of irradiating the side.
The position of the first mirror was displaced from the first position to the second position by the first mirror moving means, emitted from the first light source on the first surface of the substrate, and reflected on the surface of the first mirror. The first optical scanning step of scanning linear light.
A first imaging step in which the first surface of the substrate is imaged by an imaging means between the first light irradiation start step and the first light scanning step.

A first image processing step of processing an image obtained in the first imaging step.

Hereinafter, each step will be described.
(First light irradiation start process)
In the first light irradiation start step, the linear light emitted from the first light source is connected to the first mirror moving means, reflected by the surface of the first mirror arranged at the first position, and installed on the substrate stage. It is possible to irradiate the first surface side of the substrate.

Since the first light source, the first mirror moving means, the shape of the linear light, etc. have already been described, detailed description thereof will be omitted, but the first light source is a means capable of irradiating the linear light as described above. Can be used, and 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 simultaneously irradiate a plurality of linear lights parallel to each other. In this case, the spacing between the plurality of linear lights is adjusted so that a dark region is formed between the plurality of bright regions that reflect the plurality of linear lights emitted through the first mirror. It is preferable to keep it.

In the first optical scanning step described later, by moving the position of the bright region, the first imaging region and the second imaging region to be imaged by the imaging means are moved, and the first imaging region and the second imaging region are moved. It is preferable that an image of a portion to be inspected, for example, an image of the entire surface of the substrate can be formed when the images captured in the above are stitched together. Therefore, in the light irradiation start step, for example, it is preferable that a bright region can be formed at or near the first end portion which is an arbitrary end portion on the surface of the substrate. Therefore, when the first mirror is arranged at the first position, the first mirror moving means can irradiate the first end, which is an arbitrary end on the surface of the substrate, with the light reflected by the first mirror. It is preferable to adjust the position.
(First optical scanning step)
In the first light scanning step, the position of the first mirror is displaced from the first position to the second position by the first mirror moving means, and the light is emitted from the first light source on the first surface of the substrate. The linear light reflected on the surface of the first mirror can be scanned.

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

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

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

Further, when the bright region is intermittently moved, the first optical scanning step and the first imaging step can be alternately performed. That is, in the first light scanning step, the bright region can be moved by a certain distance and stopped, then the first imaging step can be performed, and after the first light scanning step is performed again, the first imaging step can be carried out.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

Further, as described above, the substrate inspection device 10 may further include a second light source 22, a second mirror 23, and a second mirror moving means 24 on the second surface 16B side of the substrate 16.
Then, when the substrate inspection device includes these members, that is, when the second light source is arranged on the second surface side located on the side opposite to the first surface of the substrate, the present embodiment The substrate inspection method may further include the following steps.

The linear light emitted from the second light source is connected to the second mirror moving means, reflected on the surface of the second mirror arranged at the third position, and irradiates the second surface side of the substrate. Second light irradiation start step.
The position of the second mirror was displaced from the third position to the fourth position by the second mirror moving means, emitted from the second light source on the second surface of the substrate, and reflected on the surface of the second mirror. A second light scanning step of scanning linear light.
A second imaging step in which the first surface of the substrate is imaged by an imaging means between the second light irradiation start step and the second light scanning step.
A second image processing step of processing the image obtained in the second imaging step.

Hereinafter, each step will be described.
(Second light irradiation start process)
In the second light irradiation start step, the linear light emitted from the second light source is connected to the second mirror moving means, reflected by the surface of the second mirror arranged at the third position, and installed on the substrate stage. It is possible to irradiate the second surface side of the substrate.

Since the second light source, the second mirror moving means, the shape of the linear light, etc. have already been described, detailed description thereof will be omitted, but the second light source is a means capable of irradiating the linear light as described above. Can be used, and the configuration is not particularly limited. However, from the viewpoint of improving the efficiency of inspection, it is preferable that the second light source can simultaneously irradiate a plurality of linear lights parallel to each other. 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 second optical scanning step described later, it is preferable that the position of the transmission region is moved and an image of a portion to be inspected when the images of the transmission region are stitched together, for example, an image of the entire surface of the substrate can be formed. .. Therefore, in the second light irradiation start step, for example, it is preferable that a transmission region can be formed at or near the first end portion which is an arbitrary end portion on the surface of the substrate. Therefore, when the second mirror is arranged at the third position, the second mirror moving means irradiates the first end, which is an arbitrary end on the surface of the substrate, with the light reflected by the second mirror. It is preferable to adjust the position so that the transmission region can be formed.
(Second optical scanning step)
In the second light scanning step, the position of the second mirror is displaced from the third position to the fourth position by the second mirror moving means, and the second mirror is emitted from the second light source on the second surface of the substrate. 2 It is possible to scan the linear light reflected on the surface of the mirror.

The specific conditions for scanning the irradiation position of the light emitted from the second light source in the second light scanning step are not particularly limited. However, as described above, in the second optical scanning step, when the position of the transmission region is moved and the images of the transmission region are stitched together, an image of a portion to be inspected, for example, an image of the entire substrate surface is formed. It is preferable to be able to do it. Therefore, in the second light scanning step, the transmission region is set along the direction orthogonal to the longitudinal direction of the transmission region, and the end portion opposite to the first end portion described in the second light irradiation start step. That is, it is preferable to move the straight line passing through the first end portion and the center of the substrate to the second end portion orthogonal to the end portion of the substrate because it is efficient and the substrate surface can be imaged without gaps.

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

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

Further, when the transmission region is intermittently moved, the second optical scanning step and the second imaging step can be alternately performed. That is, in the second light scanning step, the transmission region can be moved by a certain distance and stopped, then the second imaging step can be performed, and after the second light scanning step is performed again, the second imaging step can be carried out.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Further, in the substrate inspection method of the present embodiment, 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. Furthermore, by moving the first mirror and the second mirror, the substrate can be inspected without moving the light source or the imaging means. Therefore, the entire inspection device for the substrate to be used can be miniaturized, and the cost can be suppressed.

10 Substrate inspection device 11 Substrate stage 12 First light source 13 First mirror 13A First position 13B Second position 14 First mirror moving means 15 Imaging means 16 Substrate 16A First surface 16B Second surface 18 Image processing means 22 Second light source 221 Light source control means 23 Second mirror 23A Third position 23B Fourth position 24 Second mirror moving means 31A Bright area 32A, 32B First image area 33 Second image area 41A Transmission area

Claims (10)

Board stage and
With the first light source
The first mirror and
A first mirror moving means that is connected to the first mirror and can displace the first mirror between the first position and the second position.
An imaging means for imaging the first surface side of the substrate arranged on the substrate stage, and
It is provided with an image processing means for processing an image obtained by the imaging means.
The first mirror moving means displaces the first mirror from the first position to the second position, so that linear light emitted from the first light source and reflected on the surface of the first mirror. A substrate inspection device capable of scanning the substrate on the first surface of the substrate. A second light source arranged on the second surface side located on the side opposite to the first surface of the substrate, and
A second mirror arranged on the second surface side of the substrate,
A second mirror moving means that is connected to the second mirror and can displace the second mirror between the third position and the fourth position.
Further, the first light source and the light source control means for controlling the light emission of the second light source are provided.
The second mirror moving means displaces the second mirror from the third position to the fourth position to emit light emitted from the second light source and reflected on the surface of the second mirror. The substrate inspection apparatus according to claim 1, which can scan on the second surface of the substrate. The substrate inspection device according to claim 1 or 2, wherein the imaging means is a line scan camera. The substrate inspection apparatus according to any one of claims 1 to 3, further comprising an inclination correcting means for leveling the substrate. The substrate inspection apparatus according to any one of claims 1 to 4, wherein the first light source can irradiate a plurality of linear lights parallel to each other. The linear light emitted from the first light source is connected to the first mirror moving means, reflected by the surface of the first mirror arranged at the first position, and reflected on the surface of the first mirror arranged at the first position, and the first surface of the substrate installed on the substrate stage. The first light irradiation start step of irradiating the side and
The position of the first mirror is displaced from the first position to the second position by the first mirror moving means, and is emitted from the first light source on the first surface of the substrate. 1 The first light scanning step of scanning the linear light reflected on the surface of the mirror, and
From the first light irradiation start step to the first light scanning step, a first imaging step of imaging the first surface of the substrate by an imaging means, and a first imaging step.
A method for inspecting a substrate, comprising a first image processing step of processing an image obtained in the first imaging step. A second light source is arranged on the second surface side of the substrate, which is located on the side opposite to the first surface of the substrate.
The linear light emitted from the second light source is connected to the second mirror moving means, reflected on the surface of the second mirror arranged at the third position, and irradiates the second surface side of the substrate. The second light irradiation start process and
The position of the second mirror is displaced from the third position to the fourth position by the second mirror moving means, and the second mirror is emitted from the second light source on the second surface of the substrate. 2 The second light scanning step of scanning the linear light reflected on the surface of the mirror, and
From the second light irradiation start step to the second light scanning step, a second imaging step of imaging the first surface of the substrate by the imaging means, and
The substrate inspection method according to claim 6, further comprising a second image processing step of processing the image obtained in the second imaging step. The substrate inspection method according to claim 6 or 7, wherein the imaging means is a line scan camera. The method for inspecting a substrate according to any one of claims 6 to 8, further comprising a tilt correction step for leveling the substrate. The method for inspecting a substrate according to any one of claims 6 to 9, wherein the first light source can irradiate a plurality of linear lights parallel to each other.

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