KR102043660B1 - Optical System for Inspecting Transparent Layer and Apparatus for Inspecting Transparent Layer Including the Same - Google Patents

Abstract

Disclosed are an optical system for inspecting a transparent layer and an apparatus for inspecting a transparent layer including the same. According to an aspect of the present invention, the optical system for inspecting a defect existing in a transparent layer of a substrate comprises: a light source configured to irradiate light having an incident angle less than a predetermined angle to the transparent layer; and a light receiving unit configured to receive and sense light reflected from the transparent layer to check a defect existing in the transparent layer.

Description

Transparent System for Inspecting Transparent Layer and Apparatus for Inspecting Transparent Layer Including the Same

The present invention relates to an optical system capable of inspecting a transparent layer in a substrate and a transparent layer inspection apparatus including the same.

The contents described in this section merely provide background information on the present embodiment and do not constitute a prior art.

A display device such as an LCD (Liquid Crystal Display) is configured to include a transparent layer such as glass or a transparent film. The transparent layer has a via hole or the like formed in a pattern formed of an electrode material such as indium tin oxide (ITO) or a predetermined size and location.

On the other hand, the foreign material may be introduced for a variety of reasons in the manufacturing process, packaging process or pattern forming process using the thin transparent layer of the same thickness. Foreign materials introduced in these process environments affect the patterns or via holes to be formed in the transparent layer, causing defects.

Therefore, in the related art, there exists an apparatus for inspecting the defect in the transparent layer which is caused.

In the conventional defect inspection apparatus formed in the transparent layer irradiated with light having an angle of incidence of the Brewster Angle (Brewster Angle) or more to the transparent layer, by sensing the reflected light to inspect the defect formed in the transparent layer. The Brewster angle means an angle at which the light beams parallel to the plane of incidence are not reflected at all when the light rays reflected from a specific medium and the light rays incident and refracted by a specific medium form 90 degrees. In the conventional defect inspection apparatus, most of the light is reflected from the surface of the transparent layer by using Brewster's angle to solve the problem of inferior inspection accuracy of the defect present on the surface of the transparent layer due to the pattern of the opaque layer existing under the transparent layer. By sensing the reflected light, defects formed mainly on the surface of the transparent layer were examined.

However, since most of the light irradiated by the conventional defect inspection apparatus is reflected on the surface of the transparent layer, the hole defects generated in the transparent layer have a problem that inspection is difficult. Since a conventional defect inspection apparatus irradiates light at a Brewster angle or an angle of incidence higher, the aperture is not detected with a sufficient size even if there is a defect in the opening in the transparent layer. Accordingly, the conventional defect inspection apparatus can only inspect the defects existing on the surface of the transparent layer, and there is a problem that the defects in the openings present in the transparent layer cannot be sufficiently inspected.

One embodiment of the present invention is to provide a transparent layer inspection optical system and a transparent layer inspection apparatus including the same that can inspect all the defects formed in the transparent layer as well as the surface of the transparent layer in the substrate without additional configuration.

According to one aspect of the invention, in the optical system for inspecting the defects present in the transparent layer of the substrate, the light source for irradiating light having an angle of incidence less than a predetermined angle to the transparent layer and the defects present in the transparent layer, It provides a transparent layer inspection optical system comprising a light receiving unit for receiving and sensing the light reflected from the transparent layer at a reflection angle corresponding to the incident angle.

According to an aspect of the invention, the predetermined angle is characterized in that the Brewster Angle (Brewster Angle) of the transparent layer.

According to an aspect of the invention, the light source is characterized in that for irradiating light of a wavelength band relatively short compared to the red wavelength band.

According to an aspect of the invention, the light source is characterized in that for irradiating light of the blue wavelength band sensitive to the angle.

According to an aspect of the invention, the defects present in the transparent layer is characterized in that it includes not only the defects present on the surface of the transparent layer but also the openness defects formed in the transparent layer.

According to an aspect of the present invention, in the apparatus for inspecting a defect present in the transparent layer of the substrate, the substrate transfer unit for transferring the substrate to be inspected or the inspection is completed in a predetermined direction and the angle of incidence below the predetermined angle to the transparent layer An optical system for irradiating light having a light intensity and receiving light reflected from the transparent layer at a reflection angle corresponding to the incident angle, and analyzing the information sensed by the optical system to determine whether there is a defect in the transparent layer. Provided is a transparent layer inspection apparatus, characterized in that.

According to an aspect of the invention, the predetermined angle is characterized in that the Brewster Angle (Brewster Angle) of the transparent layer.

According to an aspect of the present invention, the optical system is characterized in that for irradiating light of a wavelength band relatively short compared to the red wavelength band to the transparent layer.

According to an aspect of the invention, the optical system is characterized in that for irradiating light in the blue wavelength band sensitive to angle.

According to an aspect of the present invention, the analysis unit analyzes the information sensed by the optical system, to determine whether not only the defects present on the surface of the transparent layer, the desired or unwanted openings formed in the transparent layer. do.

As described above, according to an aspect of the present invention, there is an advantage that can inspect all defects formed on the transparent layer as well as the surface of the transparent layer in the substrate even without a separate additional configuration.

1 is a view showing the configuration of a transparent layer inspection apparatus according to an embodiment of the present invention.
2 is a diagram illustrating an embodiment of an optical system according to an embodiment of the present invention.
3 is a diagram illustrating an operation of an optical system according to an exemplary embodiment of the present disclosure and an inspection result analyzed by the transparent layer inspection apparatus therefrom.
4 is a diagram showing an operation of a conventional optical system and inspection results analyzed by the transparent layer inspection apparatus therefrom.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. It is to be understood that the term "comprises" or "having" in the present application does not exclude in advance the possibility of the presence or addition of features, numbers, steps, operations, components, parts or combinations thereof described in the specification. .

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In addition, each component, process, process, or method included in each embodiment of the present invention may be shared within a range that is not technically contradictory.

1 is a diagram showing the configuration of a transparent layer inspection apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the transparent layer inspection apparatus 100 according to an embodiment of the present invention may include a substrate transfer unit 110, a transparent layer inspection optical system 120 (hereinafter abbreviated as an “optical system”), an analysis unit 130, and a controller. 140.

The substrate includes a transparent layer (PID: Photo Imageable Dielectric) to be inspected. The transparent layer reflects all the light in all wavelength bands or reflects some light and transmits the remaining light according to the incident angle of the incident light. After entering the transparent layer, the transparent layer inspection device receives and senses the light reflected from the transparent layer to inspect the openness defect formed on the surface or the transparent layer of the transparent layer. However, when the light reflected by the opaque layer positioned at the bottom of the transparent layer in the substrate after entering the transparent layer is incident to the transparent layer inspection device, the transparent layer inspection device is difficult to clearly check whether the pattern of the opaque layer or the like is formed in the transparent layer, There is an inconvenience of having to perform additional work for clear inspection. In order to solve this problem, the conventional transparent layer inspection apparatus prevents light from reaching the opaque layer at the bottom of the transparent layer by irradiating light at an incident angle at which most of the light incident from the surface of the transparent layer is reflected. However, the transparent layer inspection apparatus 100 can inspect whether there is a defect in the transparent layer accurately without fine adjustment of the angle of incidence of light, and can inspect not only a defect formed on the surface of the transparent layer but also an opening defect formed in the transparent layer. Have

The substrate transfer unit 110 transfers the substrate including the transparent layer to be inspected to the optical system 120, or transfers the substrate including the inspected transparent layer to another component (not shown) or an apparatus (not shown).

The optical system 120 irradiates light to the transferred inspection target transparent layer, and receives and senses light reflected from the transparent layer.

The optical system 120 irradiates light of a predetermined wavelength band to the inspection target transparent layer, but irradiates light at an incident angle equal to or less than a preset angle. When irradiated at an angle of incidence above a predetermined angle so that most of the light is reflected from the surface of the transparent layer, the amount of light received is increased, so that inspection of defects on the surface of the transparent layer can be made easier, but in this case, the transparency to the transparent layer is remarkably increased. There is a problem in that inspection becomes difficult with respect to the poor openness formed in the transparent layer. Therefore, the optical system 120 irradiates light having an incident angle equal to or less than a predetermined angle to the transparent layer in order to inspect all defects formed in the transparent layer.

The optical system 120 receives and senses light reflected from the transparent layer. The optical system 120 receives only the light reflected from the transparent layer. As in the conventional inspection apparatus, not only the light reflected from the transparent layer but also scattered or diffusely reflected light is received, only the light reflected from the transparent layer is received. Accordingly, the light transmitted through the transparent layer without being reflected from the transparent layer is off the path that can be received by the optical system 120, and thus is not sensed by the optical system 120. By using such a characteristic, the optical system 120 may determine not only a defect occurring on the surface of the transparent layer, but also an opening defect formed in the transparent layer. Detailed description of the optical system 120 will be described later with reference to FIGS. 2 to 4.

The analyzer 130 analyzes the information sensed by the optical system 120 to determine whether there is a defect in the transparent layer. The analysis unit 130 may store information on the transparent layer in which the defect does not exist, and determine whether the defect exists in the transparent layer by various methods such as comparing the stored information with information sensed by the optical system 120. . The defects that can be detected by the analysis unit 130 include a material that is not to be applied to the surface of the transparent layer, or a material that is not properly applied, a transparent layer such as scratches or scratch grooves generated on the surface of the transparent layer, or foreign substances introduced into the surface of the transparent layer. There is a defect occurring on the surface. In addition, an additional defect that can be recognized by the analysis unit 130 includes an opening defect such as an opening formed in a portion larger or smaller than an area set in the transparent layer or an opening formed in an unset portion. The analysis unit 130 determines whether such a defect exists in the transparent layer.

The controller 140 controls the operation of each component in the transparent layer inspection apparatus 100. The controller 140 controls the substrate transfer unit 110 to transfer the substrate to the optical system 120 or another device (not shown). Alternatively, the controller 140 controls the optical system 120 and the analyzer 130 to check whether there is a defect in the transparent layer.

2 is a view showing an embodiment of an optical system according to an embodiment of the present invention.

2, the optical system 120 according to an embodiment of the present invention includes a light source 210, a first collimator 220, a bandpass filter 230, a first linear polarizer 240, and a second linear polarizer. 250, a second collimator 260, and a light receiver 270.

The light source 210 irradiates light of a predetermined wavelength band to the transparent layer 280 at an incident angle equal to or less than a preset angle.

The light source 210 irradiates light of a predetermined wavelength band with the transparent layer 280. The wavelength band of the light irradiated by the light source 210 is light of a short wavelength band, that is, blue light (450 nm to 495 nm). The longer the wavelength, the more the light transmittance to the object is improved, and the image that is reflected and sensed is not clear, whereas the shorter the wavelength is, the transmittance is lowered, the reflectance is increased and the light source 210 is sensitive. Irradiates light of a short wavelength band. However, the defect inspection for the transparent layer 280 is performed before curing of the transparent layer 280 to repair the defects existing in the transparent layer 280 before curing, or to confirm whether the transparent layer 280 is cured as desired. It may be performed after curing the transparent layer 280. In consideration of this characteristic, the light source 210 may set the wavelength of light to be irradiated differently before and after curing of the transparent layer 280. Before curing of the transparent layer 280, the light source 210 unconditionally receives light of the shortest wavelength band within an area that is out of a predetermined wavelength range from the wavelength band of light for curing the transparent layer 280, not light of a short wavelength band. Investigate. On the other hand, after curing of the transparent layer 280, the light source 210 may improve the defect inspection rate by irradiating blue light, which is light of the shortest wavelength band. For example, when ultraviolet (UV) is used to cure the transparent layer 280, the light source 210 may use green light (495 nm to 570 nm) instead of blue light closest to the ultraviolet wavelength band for curing the transparent layer 280. Can be. Since the wavelength band of blue light is substantially adjacent to the wavelength band of ultraviolet light, there exists a possibility that the transparent layer 280 will harden | cure during defect inspection. Accordingly, even if a defect exists in the transparent layer 280 as a result of the inspection, hardening may be completed and difficulty in repairing the defect may exist. Therefore, in the above-described situation, the light source 210 may radiate green light to the transparent layer 280.

The light source 210 is irradiated with the transparent layer 280 at an incident angle equal to or less than a preset angle. Here, the preset angle may be a Brewster angle, and in particular, may be 45 degrees. Intentionally, the light source 210 irradiates light at an angle outside the Brewster Angle according to the medium of the transparent layer 280. The light irradiated at an angle of incidence less than or equal to a predetermined angle is somewhat less reflected by the transparent layer 280, but allows the analyzer 130 to clearly distinguish the poor aperture 285 formed in the transparent layer 280.

The light source 210 may be implemented as a light source for irradiating light instead of a laser. Lasers do not emit light evenly, which is not suitable for inspecting defects in the transparent layer. Therefore, the light source 210 may be implemented as a light source, for example, an LED, which irradiates light instead of a laser.

The first collimator 220 converts the light irradiated from the light source 210 into parallel light. Since the light irradiated from the light source 210 is diffused and irradiated, the first collimator 220 converts the light into parallel light. When the light is dispersed and irradiated to the transparent layer 280, the amount of light reflected by the transparent layer 280 is reduced, so that there is a problem in that poor irradiation efficiency is lowered. The first collimator 220 may be implemented as a telecentric lens, but is not necessarily limited thereto, and may be replaced with any structure as long as it is capable of collimating light.

The bandpass filter 230 filters only the light of a specific region of the light emitted from the light source 210 to pass. The bandpass filter 230 allows only light in a predetermined region to pass from the center wavelength and filters the remaining wavelength band. The bandpass filter 230 allows only the light of the appropriate wavelength band to be irradiated to the transparent layer 280, and the remaining light is filtered. In addition, the bandpass filter 230 may vary in the wavelength band passed according to the situation. In the above-described example, if the situation is before the transparent layer is cured, the bandpass filter 230 may filter to pass only light in a predetermined region around the green wavelength band, and if the transparent layer is cured, the bandpass filter The filter 230 may filter so that only light in a predetermined area passes through the blue wavelength band. The bandpass filter 230 filters the wavelength band based on the wavelength band, thereby making the wavelength of the light irradiated from the light source 210 uniform, resulting in an effect as if the laser is irradiated.

The first linear polarizer 240 polarizes the light passing through the bandpass filter 230 in a direction S Pol perpendicular to the plane of incidence. According to Brewster's law, when light rays reflected from a specific medium and light rays incident and refracted by a specific medium form 90 degrees, light rays parallel to the plane of incidence are not reflected at all. When light is incident on a specific medium at such Brewster angle, the light beam P Pol whose polarization direction is parallel to the incident plane is not reflected. Therefore, when the light is incident on the transparent layer 280 at an angle of incidence close to the angle of Brewster, although not necessarily the Brewster angle, the light beam S Pol whose polarization direction is perpendicular to the plane of incidence is relatively reflected and the polarization direction is incident. Light rays P Pol parallel to the plane produce relatively little reflection. Using this feature, the first linearly polarizing plate 240 polarizes the light passing through the bandpass filter 230 in a direction S Pol perpendicular to the plane of incidence, so that the reflective layer 280 has a large reflection on the surface. Get up.

The second linear polarizer 250 polarizes the light reflected by the transparent layer 280 in the direction S Pol perpendicular to the plane of incidence again. Reflection occurs in the transparent layer 280, and a part of the light condensation component is added to the reflected light. In order to remove such a light component, the second linear polarizer 250 linearly polarizes the light reflected by the transparent layer 280 again.

The second collimator 260 is disposed at a predetermined angle to convert light passing through the second linear polarizer 250 into parallel light.

The second collimator 260 is disposed at a preset angle to receive only the light reflected at the preset angle. The second collimator 260 is disposed at an angle of the reflection angle of the light incident on the transparent layer 280, and receives light that is completely reflected without diffuse reflection in the transparent layer 280. The light irradiated onto the transparent layer 280 is reflected from the surface except for a part of the light incident to the second collimator 260 when there is no defect. However, when there is a defect on the surface of the transparent layer 280 or there is an open defect 285 in the transparent layer 280, the light incident on the transparent layer 280 is not completely reflected, diffuse reflection occurs or the reflection path is changed. Such light is not received by the second collimator 260. The second collimator 260 receives only the light that is completely reflected from the transparent layer 280 without a separate variable, so that the second collimator 260 may determine whether there is a defect in the transparent layer.

The light receiver 270 receives and senses light passing through the second collimator 260. The light receiving unit 270 is configured to receive and sense light such as a camera or an optical sensor, so that the analyzer 130 may analyze the light by sensing light. For example, when the light receiver 270 is implemented as a camera, the analyzer 130 may analyze an image sensed by the light receiver 270 to check whether a defect exists in the transparent layer 280.

3 is a diagram illustrating an operation of an optical system and an inspection result analyzed by the transparent layer inspection apparatus therefrom according to an embodiment of the present disclosure.

As described with reference to FIG. 2, the light source 210 irradiates light at an incident angle equal to or less than a preset angle. When there is an opening defect 285 in the transparent layer 280, the light irradiated from the light source 210 is not reflected from the surface of the transparent layer 280, but passes through the opening defect 285 and is an opaque layer at the bottom of the transparent layer 280. 290 may be entered. As the light irradiated from the light source 210 is reflected by the opaque layer 290, the light is emitted from the second collimator 260 and the light receiver 270 because it is off the path reflected from the surface of the transparent layer 280. Accordingly, as shown in FIG. 3B, in the image sensed and analyzed by the light receiving unit 270 or the analysis unit 130, a dark portion corresponding to the area of the defective opening 285 exists. That is, since the light source 210 irradiates light at an angle of incidence less than or equal to a predetermined angle, the optical system 120 can accurately inspect not only the defect existing on the surface of the transparent layer, but also the size and area of the aperture defect 285. . Accordingly, the optical system 120 may determine whether an opening of a desired size or area exists at a desired position of the transparent layer or whether the opening exists at a position that should not exist in the transparent layer, thereby resulting in poor apertures 285 of the transparent layer 280. You can check until.

4 is a diagram illustrating an operation of a conventional optical system and inspection results analyzed by the transparent layer inspection apparatus therefrom.

On the other hand, as described in the background section, the conventional optical system irradiates light at an angle of incidence at Brewster's angle to check for defects on the surface of the transparent layer 280. The defect may be inspected, but there is a problem in that the open defect 285 existing in the transparent layer 280 cannot be inspected completely. Since the light has a very large angle of incidence and light is irradiated to the transparent layer 280, even a poor aperture 285 having a certain area or size is detected at a very fine size or is not detected depending on the incident angle of the light or the area or size of the opening. You may not. Due to this problem, the conventional optical system was inconvenient to inspect only the defect on the surface of the transparent layer 280.

The optical system 120 according to an embodiment of the present invention allows light to be irradiated to the transparent layer 280 at an angle of incidence below a predetermined angle, and receives and senses only light that is reflected at a predetermined angle, thereby causing a path of light due to poor aperture. By detecting even the change of, the defect of opening can be inspected.

The above description is merely illustrative of the technical idea of the present embodiment, and those skilled in the art to which the present embodiment belongs may make various modifications and changes without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of the present embodiment but to describe the present invention, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

100: transparent layer inspection device
110: substrate transfer part
120: transparent layer inspection optical system
130: analysis unit
140: control unit
210: light source
220: first collimator
230: bandpass filter
240: first linear polarizer
250: second linearly polarizing plate
260: second collimator
270: light receiver
280: transparent layer
285: poor aperture
290: opaque layer

Claims (10)

In the optical system for inspecting a defect present in the transparent layer of the substrate,
Irradiate light having an angle of incidence below the Brewster angle of the transparent layer to the transparent layer, and irradiate light of the shortest wavelength band within a region outside the preset wavelength range from the wavelength band of the light curing the transparent layer before curing of the transparent layer. A light source irradiating light of the shortest wavelength band irradiated after curing of the transparent layer;
A first collimator for converting the light irradiated from the light source into parallel light to prevent diffusion of the light irradiated from the light source;
A first linear polarizer configured to increase the amount of reflection on the surface of the transparent layer by polarizing the light passing through the first collimator in a direction perpendicular to the plane of incidence;
A second linear polarizer configured to re-polarize light reflected from the transparent layer in a direction perpendicular to the plane of incidence;
Only the light reflected at the reflection angle excluding the defect formed on the surface of the transparent layer among the light passing through the second linear polarizing plate and the light whose path is changed by the opening defect is disposed as the parallel light. A second collimator for converting; And
In order to check for defects in the transparent layer, the light receiving unit is arranged to receive and sense light passing through the second collimator.
Transparent layer inspection optical system comprising a. delete delete delete The method of claim 1,
The defect present in the transparent layer,
Transparent layer inspection optical system comprising not only defects present on the surface of the transparent layer but also openness defects formed in the transparent layer. delete delete delete delete delete

Images