KR102656784B1 - Light reflection support and through hole inspection system - Google Patents

Abstract

The present invention is a light reflection supporter that stably supports a glass substrate to be inspected and reflects illumination light to the lower part of the glass substrate disposed on the opposite side of the imaging unit to increase inspection precision from a clear photographed image of the through hole, and a light reflection supporter including the same. Provides a through-hole inspection system. The light reflection supporter is used in a device that photographs a through hole formed in a substrate and inspects whether the through hole is normal from the captured image, and includes a transparent support part and a reflective layer part. The transparent support part supports the substrate and has a suction hole extending into a solid area of the substrate where a through hole is not formed. The reflective layer portion is disposed on the transparent support portion and reflects light incident from the opposite side of the substrate.

Description

Light reflection support and through hole inspection system {LIGHT REFLECTION SUPPORT AND THROUGH HOLE INSPECTION SYSTEM}

The present invention relates to a light reflection supporter and a through-hole inspection system, and more specifically, to a through-hole formed in a glass substrate by reflecting illumination light to the lower part of the glass substrate disposed on the opposite side of the imaging unit while stably supporting the glass substrate to be inspected. It relates to a light reflection supporter that can increase inspection precision and a through-hole inspection system including the same.

Typically, a glass substrate is formed with a plurality of via channels (hereinafter referred to as through holes), and their positions and shapes must be inspected to ensure that they meet specifications.

A through hole in a glass substrate may have a narrower center diameter than both ends depending on the nature of the hole being processed chemically, such as etching, rather than a mechanical processing process, such as drilling. In this way, the through hole of a glass substrate with a narrow waist diameter in the center must be inspected in all areas of the upper diameter, lower diameter, and waist diameter of the hole.

Meanwhile, as a method of measuring the through hole of a glass substrate, it is possible to check whether the location and shape of the through hole are normal based on a photographed image taken from a camera.

Relatedly, there is a glass substrate inspection system with a hole in Republic of Korea Patent Publication No. 2557965 (hereinafter referred to as Prior Document 1).

Prior Document 1 includes a camera installed on the upper or lower side of a glass substrate having a through hole, a light source (illumination) installed on the lower or upper side of the glass substrate, and inspection of the through hole in the glass substrate from the captured image taken by the camera. Includes an inspection module that As described above, in this prior document 1, the upper part of the through hole is first photographed, and then the glass substrate is flipped up and down using a reversal unit to inspect the waist diameter and bottom diameter of the through hole, which has a concave shape, and then the through hole is inverted. Follow the steps to re-photograph the lower part.

However, in Prior Document 1, the inspection process takes a lot of time due to the inversion operation of the glass substrate and the increase in the number of shots. In addition, there are difficulties in the facility structure, such as the need to add complex substrate handling units such as a substrate inversion unit and a substrate holding unit in addition to the substrate transfer unit fundamentally required for the in-line glass substrate inspection process.

As an alternative to Prior Literature 1, there is a method of installing additional lower lighting such as a reflector on the lower part of the substrate on the opposite side of the light source and camera without flipping the glass substrate up and down in order to increase inspection precision for the waist diameter and lower diameter of the through hole.

However, as described above, in the inspection process of an in-line glass substrate, there are structural difficulties in installing the lower lighting due to interference from the substrate transfer unit, etc. In particular, in the in-line inspection process, it is common to use a suction pad for loading and unloading the substrate. In this case, there is structural interference between the suction hole of the suction pad to transmit the suction force to the substrate and the lower light to transmit the illumination light to the substrate. Therefore, it is difficult to implement actual facilities.

Therefore, there is a need for an inspection system with a new structure that can stably support the glass substrate, effectively transmit light to the bottom of the glass substrate placed on the other side of the camera, and perform inspection of through holes quickly and accurately.

Republic of Korea Patent Publication No. 2557965 (announced on July 20, 2023)

The task of the present invention to solve the above-described problems is to improve inspection precision from a clear image of the through hole by reflecting the illumination light to the lower part of the glass substrate disposed on the opposite side of the imaging unit while stably fixing and supporting the glass substrate to be inspected. To provide a light reflecting support and a through-hole inspection system including the same.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description below. .

The light reflecting support according to an embodiment of the present invention for solving the above-mentioned problems is used in a device for photographing a through hole formed in a substrate and inspecting whether the through hole is normal from the photographed image, supports the substrate, and a transparent support portion having a suction hole extending into a solid area of the substrate where a through hole is not formed; and a reflective layer portion disposed on the transparent support portion and reflecting light incident from the opposite side of the substrate.

In the light reflective supporter according to an embodiment of the present invention, the reflective layer portion is preferably disposed on the lower surface of the transparent supporter to be spaced apart from the substrate.

In the light reflecting supporter according to an embodiment of the present invention, the thickness of the transparent support part is preferably 2 mm or less.

A through-hole inspection system according to an embodiment of the present invention photographs a through-hole formed in a substrate and inspects whether the through-hole is normal from the captured image, including a light source unit that irradiates light to the substrate; a photographing unit that photographs the substrate; A light reflection unit having a transparent support part that supports the substrate and has a suction hole extending to a solid area of the substrate in which the through hole is not formed, and a reflective layer part disposed on the transparent support part and reflecting light irradiated from the light source part. support; and a control unit that calculates the size of the through hole from the captured image obtained by the photographing unit.

The through-hole inspection system according to an embodiment of the present invention may further include a porous stage that supports the light reflection supporter and allows negative pressure provided from the negative pressure generator to be transmitted to the suction hole.

The through-hole inspection system according to an embodiment of the present invention may further include a focus transfer unit that moves the focus of the imaging unit in the thickness direction of the substrate.

In the through hole inspection system according to an embodiment of the present invention, the through hole has an upper diameter formed on the upper surface of the substrate, a lower diameter formed on the lower surface of the substrate, and the through hole is located at the center in the thickness direction of the substrate. It may have a waist diameter that is smaller than the upper diameter and the lower diameter.

In the through hole inspection system according to an embodiment of the present invention, the control unit calculates the size of the upper diameter from the first captured image taken while maintaining the focus of the photographing unit at the same height as the upper diameter, The size of the waist diameter is calculated from a second captured image taken while maintaining the focus of the photographing unit at the same height as the waist diameter, and the size of the waist diameter is calculated while maintaining the focus of the photographing portion at the same height as the lower diameter. The size of the lower diameter can be calculated from the third captured image.

In the through-hole inspection system according to an embodiment of the present invention, the thickness of the transparent support part is preferably 2 mm or less.

Through the light reflection supporter according to the present invention, the glass substrate being loaded and unloaded can be stably fixed and supported, and a clear photographed image of the through hole is obtained by reflecting the illumination light to the lower part of the glass substrate disposed on the opposite side of the imaging unit. This can improve the inspection precision of through holes in the glass substrate.

Through the through-hole inspection system including the light reflection supporter according to the present invention, inspection of through-holes can be performed quickly and accurately without significant structural changes in the in-line glass substrate inspection process.

The effects of the present invention are not limited to the effects described above, but should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is an illustration of a partial cross-section of a glass substrate having a through hole.
Figure 2 is an exemplary diagram of a through-hole inspection system according to an embodiment of the present invention.
Figure 3 is a cross-sectional illustration showing the substrate and light reflection support of Figure 2.
FIG. 4 is a partial cross-sectional view illustrating the light reflection support of FIG. 2.
Figure 5 is an exemplary diagram showing a photographed image captured by a photographing unit according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts unrelated to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. Additionally, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

FIG. 2 is an exemplary diagram of a through-hole inspection system according to an embodiment of the present invention, FIG. 3 is an exemplary cross-sectional view showing the substrate and light reflective supporter of FIG. 2, and FIG. 4 is a diagram for explaining the light reflective supporter of FIG. 2. This is an example partial cross-section.

Referring to FIGS. 2 to 4, the through hole inspection system according to an embodiment of the present invention basically photographs the substrate 1 and inspects the through hole 2 formed in the substrate 1 based on the photographed image. Hole processing information such as location, shape, and value can be calculated, and from that, it is possible to check whether the through hole (2) is normal.

In this way, the through-hole inspection system measures and calculates the processing information of the through-hole (2) that requires inspection, such as the location, shape, and value of the through-hole (2), and determines whether the through-hole (2) is acceptable or not from this. , The following description will be based on the diameter, which is representative processing information of the through hole 2.

The substrate 1 to be inspected may be made of a transparent substrate such as glass, and may have a plurality of through holes 2.

Each through hole 2 may have a shape in which the inner center is concave than the surface diameter. That is, the through hole 2 has an upper diameter (a) formed on the upper surface of the substrate 1, a lower diameter (b) formed on the lower surface of the substrate 1, and a central portion in the thickness direction of the substrate 1. It may have a waist diameter (c) that is smaller than the upper diameter (a) and lower diameter (b).

That is, according to the through hole inspection system of the present invention, the upper diameter (a), lower diameter (b), and waist diameter (c) of the through hole (2) formed in the substrate (1) can be accurately measured and calculated.

The through hole inspection system according to this embodiment may include a light source unit 10, a photographing unit 20, a light reflection supporter 30, and a control unit.

The light source unit 10 may be disposed on one side, the upper side, of the substrate 1, and may irradiate light toward the substrate 1.

The imaging unit 20 may be disposed on one side, the upper side, of the substrate 1, and may photograph the substrate 1 irradiated with light.

The light reflection supporter 30 may be disposed on the lower side of the substrate 1, which is opposite to the light source unit 10 and the imaging unit 20 with respect to the substrate 1.

The light reflection supporter 30 can fix and support the substrate 1 and at the same time reflect light emitted from the light source unit 10 to provide illumination light to the lower part of the substrate 1, which is opposite to the light source unit 10.

The light reflection supporter 30 may have a transparent support part 31 and a reflective layer part 32.

The transparent support portion 31 may be made of a transparent material such as glass.

The transparent support part 31 may be disposed on the lower side of the substrate 1 and may be in close contact with the lower surface of the loaded substrate 1.

The transparent support part 31 may have a plurality of suction holes 33. When the substrate 1 is loaded on the upper surface of the transparent support part 31 and negative pressure is formed in the suction hole 33, the substrate 1 can be fixedly supported in close contact with the upper surface of the transparent support part 31.

The suction hole 33 may be formed to extend into the solid area SA of the substrate 1 where the through hole 2 is not formed so that negative pressure is not lost. As shown, the through hole 2 may extend to the edge solid area SA or the center solid area SA of the unformed substrate 1. Accordingly, the substrate 1 can maintain a flat loading state on the upper surface of the transparent support part 31.

The transparent support part 31 preferably has a thickness t of 2 mm or less.

Some of the light sources irradiated from the light source unit 10 and passing through the substrate 1 generate reflection, refraction, diffraction, and scattering phenomena in the process of passing through the transparent support unit 31. In order to minimize the phase difference due to these optical characteristics, transparent It is advantageous for the support portion 31 to have a thin thickness t of 2 mm or less.

If the thickness t of the transparent support part 31 exceeds 2 mm, reflection, refraction, diffraction, and scattering phenomena of light increase in the process of passing through the transparent support part 31 through the substrate 1. Then, since the reflection, refraction, and scattering phenomena of the light reflected from the reflection layer 32 and transmitted to the substrate 1 are accumulated and further increased, the bottom diameter (b) and the waist diameter (c) through the imaging unit 20 ) The clarity of the captured image deteriorates.

Therefore, it is desirable for the transparent support part 31 to have a thickness t of 2 mm or less so that the phase difference due to optical characteristics can be minimized.

The reflective layer portion 32 may be disposed on the upper or lower surface of the transparent support portion 31.

The reflective layer unit 32 may reflect light emitted from the light source unit 10 to provide illumination light to the lower portion of the substrate 1 .

The reflective layer portion 32 may be made of a metal material with high reflectivity, such as Al, and may be coated on the surface of the transparent support portion 31 by chemical vapor deposition or the like to form a thin film structure. By providing a reflective layer portion 32 of a thin film structure coated on the surface of the transparent support portion 31, the suction hole 33 can be guaranteed to have an unobstructed penetrating structure.

The reflective layer portion 32 may be disposed on the upper surface of the transparent support portion 31, but then there is a possibility that defects such as scratches due to friction may occur during repeated loading, unloading, and transportation of the substrate 1, resulting in The quality of images captured by the photographing unit 20 may deteriorate.

Therefore, it is preferable that the reflective layer portion 32 is disposed on the lower surface of the transparent support portion 31 so as to be spaced apart from the substrate 1. Then, the occurrence of defects in the reflective layer 32 due to friction can be suppressed even during the repeated loading, unloading, and transport of the substrate 1, and not only improves durability, but also reduces the quality of images captured by the photographing unit 20. can be prevented.

The through hole inspection system according to an embodiment of the present invention may further include a stage 40.

The stage 40 can basically fix and support the light reflection supporter 30 on which the substrate 1 is loaded, and can transport the light reflection supporter 30.

The stage 40 may be prepared to have a porous material or a porous structure. Then, the negative pressure provided from the external negative pressure generator 60 can be transmitted to the suction hole 33 of the light reflection supporter 30.

The through-hole inspection system according to an embodiment of the present invention may further include a focus transfer unit 50.

The focus transfer unit 50 can move the focus of the imaging unit 20 in the thickness direction of the substrate 1. An optical system provided in the photographing unit 20 may be used as the focus transfer unit 50.

The control unit may calculate the sizes of the upper diameter (a), lower diameter (b), and waist diameter (c) of the through hole 2 from the captured image obtained by the photographing unit 20.

Figure 5 is an exemplary diagram showing a photographed image captured by a photographing unit according to an embodiment of the present invention.

Referring to FIGS. 4 and 5, the process of calculating the sizes of the upper diameter (a), lower diameter (b), and waist diameter (c) of the through hole 2 through the control unit is described as follows.

First, the control unit sets the focus of the photographing unit 20 to be maintained at a height (h1) equal to the upper diameter (a) of the through hole (2). In this state, the photographing unit 20 photographs the substrate 1 to obtain a first photographed image. The first captured image obtained in this way may have the same form as (a) in FIG. 5. Additionally, the control unit may calculate the size of the upper diameter (a) from the first captured image using a typical image processing/filtering program based on sharpness or contrast.

Next, the control unit sets the focus of the photographing unit 20 to be maintained at a height (h2) equal to the waist diameter (c) of the through hole (2). In this state, the photographing unit 20 photographs the substrate 1 to obtain a second photographed image. The second captured image obtained in this way may have the same form as (b) in FIG. 5. Additionally, the control unit may calculate the size of the waist diameter c from the second captured image using the general image processing/filtering program described above.

Next, the control unit sets the focus of the photographing unit 20 to be maintained at a height (h3) equal to the lower diameter (b) of the through hole (2). In this state, the photographing unit 20 photographs the substrate 1 to obtain a third photographed image. The third captured image obtained in this way may have the same form as (c) in FIG. 5. Here, since the light source irradiated from the light source unit 10 is reflected from the reflective layer unit 32 of the light reflection supporter 30 to the lower surface of the substrate 1, the third captured image can also have clarity equivalent to the first captured image. there is. The control unit may calculate the size of the lower diameter (b) from the third captured image using the general image processing/filtering program described above.

In this way, while adjusting the focal distance of the photographing unit 20 in the thickness direction of the substrate 1 through the focus transfer unit 50, multiple captured images are acquired in the depth direction of the through hole 2, and the obtained From multiple captured images, the sizes of the upper diameter (a), waist diameter (c), and lower diameter (b) of the through hole (2) can be accurately calculated.

Of course, according to the present invention, the upper diameter (a), waist diameter (c), and lower diameter (b) of the through hole 2 can be calculated at once from one image captured by the photographing unit 20. For example, the control unit sets the focus of the photographing unit 20 to be maintained at the same height (h2) as the waist diameter (c), which is the center of the through hole (2), and the upper part from one captured image in this state The diameter (a), waist diameter (c), and bottom diameter (b) can also be calculated at once. However, in this case, the clarity of the captured images for the upper diameter (a) and lower diameter (b) may be relatively reduced. Accordingly, the quantity of images captured in the through hole 2 can be appropriately adjusted and set in consideration of the specifications of the image processing/filtering program used or the thickness of the substrate 1.

As described above, the light reflection supporter 30 according to the present invention can stably fix and support the glass substrate 1 that is loaded and unloaded, and the glass substrate 1 disposed on the opposite side of the imaging unit 20 A clear image of the through hole 2 can be obtained by reflecting the illumination light to the lower part of the . Through this, the inspection precision for the through hole (2) of the glass substrate (1) having a waist diameter with a narrow center can be greatly increased.

In addition, the through-hole inspection system including the light reflection supporter 30 according to the present invention can quickly and accurately inspect the through-hole 2 without significant structural changes in the in-line glass substrate inspection process.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

1: substrate
2: Through hole
a: top diameter
b: bottom diameter
c: waist diameter
10: Light source unit
20: Filming Department
30: light reflection supporter
40: Stage
50: Focus transfer unit

Claims (9)

It is used in a device that photographs a through hole formed in a substrate and inspects whether the through hole is normal from the captured image.
a transparent support part supporting the substrate and having a suction hole extending into a solid area of the substrate where the through hole is not formed; and
A light reflection supporter comprising a reflective layer portion disposed on the transparent support portion and reflecting light incident from the opposite side of the substrate. According to paragraph 1,
A light reflective supporter, wherein the reflective layer part is disposed on a lower surface of the transparent support part to be spaced apart from the substrate. According to paragraph 1,
A light reflecting supporter, characterized in that the thickness of the transparent support part is 2mm or less. A through-hole inspection system that photographs a through-hole formed in a substrate and inspects whether the through-hole is normal from the captured image,
a light source unit that irradiates light to the substrate;
a photographing unit that photographs the substrate;
A light reflection unit having a transparent support part that supports the substrate and has a suction hole extending to a solid area of the substrate in which the through hole is not formed, and a reflective layer part disposed on the transparent support part and reflecting light irradiated from the light source part. support; and
A through-hole inspection system comprising a control unit that calculates the size of the through-hole from the image acquired by the photography unit. According to clause 4,
A through-hole inspection system further comprising a porous stage that supports the light reflection supporter and allows negative pressure provided from the negative pressure generator to be transmitted to the suction hole. According to clause 4,
A through hole inspection system further comprising a focus transfer unit that moves the focus of the imaging unit in the thickness direction of the substrate. According to clause 6,
The through hole is,
an upper diameter formed on the upper surface of the substrate,
A lower diameter formed on the lower surface of the substrate,
A through hole inspection system characterized in that it has a waist diameter formed at the center in the thickness direction of the substrate to a size smaller than the upper diameter and the lower diameter. In clause 7,
The control unit,
Calculate the size of the upper diameter from the first captured image taken while maintaining the focus of the photographing unit at the same height as the upper diameter,
Calculating the size of the waist diameter from a second captured image taken while maintaining the focus of the photographing unit at the same height as the waist diameter,
A through hole inspection system characterized in that the size of the lower diameter is calculated from a third captured image taken while maintaining the focus of the photographing unit at the same height as the lower diameter. According to clause 4,
A through hole inspection system, characterized in that the thickness of the transparent support part is 2 mm or less.

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