KR20160101317A - Apparatus for inspecting surface - Google Patents

Abstract

Provided is an apparatus to inspect a surface, comprising: an image device analyzing a foreign substance by detecting laser beams scattered from an object when a laser beam having a line shape is projected onto the object; and a remaining beam dump trapping laser beams having a page shape reflected from the object when the laser beam having a line shape is projected onto the object.

Description

[0001] APPARATUS FOR INSPECTING SURFACE [0002]

The present invention relates to a surface inspection apparatus including a beam dump for trapping a high-power laser beam.

The fabrication process for fabricating large-area thin film glass substrates used in LCDs and OLEDs involves coating, evaporating, light exposure, and etching a number of thin films. In the process of depositing a multilayer thin film on a glass substrate, foreign substances generated on the upper surface of the glass substrate grow as the process progresses, resulting in a fatal defective product. In addition, the foreign substance found in the post-process is already located under the film quality of the multi-layer, so that it is difficult to proceed with the repair process.

As described above, a surface inspection apparatus is indispensable in order to detect a foreign substance generated in a subsequent process in advance. The surface inspection apparatus needs a configuration of an optical system capable of detecting a foreign substance having a nanometer size. Further, due to a scattering signal that decreases as the size of the foreign object decreases, a high-power laser should be used for illumination in order to detect a foreign substance having a nanometer size. Furthermore, a device for inspecting the surface of a large-area glass substrate requires a configuration for trapping the laser beam to prevent damage to the device due to the high-power laser beam that is transmitted and reflected. Particularly, when inspecting the surface of a large-sized glass substrate, it is necessary to use a line-shaped beam instead of a point-shaped beam as the laser beam. Accordingly, a surface inspection apparatus is required to have a configuration of a laser beam dump capable of trapping and forming a reflected beam in the form of a face when a laser beam in a line form is reflected on the surface of a large-area glass substrate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface inspection apparatus including a beam dump for trapping a laser beam which is not used.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface inspection apparatus including a beam dump for trapping a high-power laser beam reflected from an object.

The various problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a surface inspection apparatus comprising: an imaging device for detecting laser beams scattered from an object when a line-shaped laser beam is incident on the object to analyze foreign matter; And a residual beam dump for trapping the laser beams of the page type reflected from the object when the laser beam of the incident laser beam is incident.

The residual beam dump includes a housing formed with an opening and formed with an opening, a beam collector connected to the housing through a rotating body for collecting the reflected laser beams, and a beam collector disposed at an opening of the housing, A diffusing portion for diffusing the laser beam into the interior of the housing, an absorption portion disposed inside the housing in a triangular pyramidal shape for absorbing the dispersed laser beams, The cooling unit may further include a cooling unit.

The beam collector has a conversion angle for converting the collected laser beams into a parallel beam in a vertical direction, and is movable at the conversion angle through the rotation body.

The beam collector may include a metal body or mirror having a highly reflective surface.

The diffusing unit may have a roughened surface that transmits the collected laser beams and disperses the collected laser beams into the inside of the housing.

The diffusing portion may include a light-transmitting material such as acrylic, quartz, and glass.

The absorber may include a core of a metallic material having a high thermal conductivity and an oxide coating having a high light absorptivity coated on the surface of the metallic material.

A reflecting mirror for changing the incident path of the laser beam irradiated from the beam irradiating unit and a shutter for changing the incident path of the laser beam according to progress of the surface inspection, .

And a beam dump for trapping the laser beam when the surface inspection does not proceed.

The beam dump includes a hollow outer member having one side opened, a diffusing member coupled to the opening of the housing and diffusing the laser beam into the outer member, An absorbing member disposed inside the outer member for absorbing the dispersed laser beams and a cooling member disposed closely to the absorber and the outer member to cool the thermal energy of the absorber and the outer member .

The details of other embodiments are included in the detailed description and drawings.

The surface inspection apparatus according to an embodiment of the present invention can safely trap a high output laser beam reflected from an object using a beam dump.

The surface inspection apparatus according to another embodiment of the present invention can safely trap a high output laser beam which is not used by using a beam dump.

The surface inspection apparatus according to an embodiment of the present invention can stably perform surface inspection by trapping a residual high power laser beam when the surface inspection is performed.

1 is a view conceptually showing a surface inspection apparatus according to an embodiment of the present invention.
2 is a conceptual diagram illustrating a residual beam dump of a surface inspection apparatus according to an embodiment of the present invention.
3 is a view conceptually showing a beam dump of a surface inspection apparatus according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the terms 'comprises' and / or 'comprising' mean that the stated element, step, operation and / or element does not imply the presence of one or more other elements, steps, operations and / Or additions.

Like reference numerals refer to like elements throughout the specification. Accordingly, although the same reference numerals or similar reference numerals are not mentioned or described in the drawings, they may be described with reference to other drawings. Further, even if the reference numerals are not shown, they can be described with reference to other drawings.

1 is a view conceptually showing a surface inspection apparatus according to an embodiment of the present invention. The surface inspection apparatus 100 is an apparatus for inspecting a foreign substance adhered on an object 30 and detects a scattered beam from the object 30 by inputting a laser beam onto the object 30, Foreign matter can be inspected. Here, the object 30 may include a large-area glass substrate. The glass substrate may be a multilayer thin film glass substrate.

1, the surface inspection apparatus 100 includes a beam irradiation unit 10, reflection mirrors 15, a beam dump 20, a shutter 25, an imaging device 40, an optical element 45, And a beam dump 50.

The beam irradiating unit 10 may irradiate the object 30 with a laser beam to detect foreign matter of the object 30. The beam irradiating unit 10 may include a high-power laser beam. The high-power laser beam is useful for detecting foreign matter having a nanometer size. This is because the smaller the size of the foreign substance is, the smaller the scattering signal becomes. A high power laser beam can use point beam.

The laser beam irradiated from the beam irradiating unit 10 can be incident on the object 30 by changing the incident path through the reflecting mirrors 15. [ That is, when the beam irradiating unit 10 can not be vertically disposed on the upper side of the object 30 in the structure of the surface inspection apparatus 100, the reflection mirrors 15 are arranged such that a laser beam The incident path can be changed so that it is incident. In the present embodiment, three reflection mirrors 15 are used to define an incident path, but the number of reflection mirrors 15 is not limited and can be adapted and applied according to the design of a person skilled in the art.

The beam dump 20 can trap unused laser beams when the surface inspection does not proceed. The beam dump 20 receives the laser beam of the point shape and can safely trap the laser beam dispersed therein. The detailed structure of the beam dump 20 will be described later in FIG.

The shutter 25 can change the incident path of the laser beam irradiated from the beam irradiating part 10 according to progress of the surface inspection. That is, when the surface inspection is proceeded, the shutter 25 closes the shutter 25 so that the laser beam can be incident on the object 30 without changing the incident path of the reflection mirrors 15. On the contrary, when the surface inspection is not advanced, the shutter 25 opens the shutter 25 to change the incident path of the reflection mirrors 15 so that the laser beam can be incident on the beam dump 20.

The optical element 45 may be disposed between the reflection mirrors 15. [ The laser beam in the form of a point can be converted into a laser beam in the form of a line through the optical element 45. Thereafter, the laser beam L incident on the object 30 may be a line-shaped beam. Here, the optical element 45 may include a prism.

The imaging device 40 can photograph the laser beams Ls scattered from the object 30 and output it as a video signal. That is, when the laser beam L is incident on the object 30, if the foreign object is present on the object 30, the incident laser beam L causes scattering. At this time, the scattered beams Ls can be photographed and output as a video signal. Here, the imaging device 40 may include a line scan camera. The imaging device 40 may include an analysis unit and may analyze the foreign substance of the object 30 by analyzing the value of the image signal output from the imaging device 40 through the analysis unit.

The residual beam dump 50 can trap the laser beams Lr reflected from the object 30. [ Since the object 30 is made of a transparent glass substrate and has a multilayer structure, multilayer reflection occurs. The reflected laser beams are in the form of a face. That is, when the laser beam L is incident on the object 30, the residual beam dump 50 can trap the laser beams Lr in the form of a face reflected from the object 30. Thus, the reflected laser beams Lr do not remain around the object 30, and the surface inspection can be performed stably. The detailed structure of the residual beam dump 50 will be described later in FIG.

2 is a conceptual diagram illustrating a residual beam dump of a surface inspection apparatus according to an embodiment of the present invention.

1 and 2, the residual beam dump 50 may include a beam collector 51, a housing 53, a diffusing portion 54, an absorbing portion 55, and a cooling portion 56 have.

The beam collector 51 may be connected to the housing 53 through the rotating body 52. Here, the rotating body 52 may include a motor. The beam collector 51 can collect the laser beams Lr reflected from the object 30 and reflect the laser beams Lr into the inside of the housing 53. At this time, the beam collector 51 has a conversion angle for converting the collected laser beams Lr into a parallel beam in a vertical direction. Here, the conversion angle is expressed by Equation (1). Herein, the angle of reflection means the angle of the laser beams Lr reflected from the object 30. The beam collector 51 can be moved at a conversion angle through the rotating body 52. [ The beam collector 51 may include a metal body or a mirror having a highly reflective surface. Thus, the beam collector 51 can collect all of the laser beam in the form of a face without reflecting it, and can reflect the laser beam to the inside of the housing 53.

The housing 53 may be formed with an opening to form the outline of the residual beam dump 50. The housing 53 may comprise a light absorbing material that absorbs the laser beam. For example, the housing 53 may include an oxide film having a high light absorption rate such as a core of a metallic material having a high thermal conductivity such as aluminum (Al) and the like and a black anodizing film coated on the surface of the metallic material .

The diffusing section 54 can be disposed in the opening of the housing 53 and can transmit the parallel beams reflected from the beam collector 51 and disperse it into the interior of the housing 53. The diffusing portion 54 may comprise a light-transmitting material such as acrylic, quartz, and glass so that a parallel beam can be transmitted. Referring to the partially enlarged view, the plane on which the parallel beam of the diffusing portion 54 is incident has a smooth structure. Therefore, the laser beam is easily transmitted. On the other hand, the surface for dispersing the beam parallel to the inside of the housing 53 has a rugged structure (R). So that the transmitted parallel beams are easily dispersed. The roughened structure R of the diffusing portion 54 may include a material having a roughness such as sanded glass or a fly-eye lens. The structure of the diffusion portion 54 may be low in absorption rate and scattered well. Thus, the high-power laser beam concentrated inside the residual beam dump 50 can be dispersed to prevent the residual beam dump 50 from being damaged.

The absorbing part 55 may be disposed inside the housing 53 in a triangular pyramid shape and formed integrally with the housing 53. The absorption portion 55 absorbs the dispersed laser beam from the diffusion portion 54 and emits it as thermal energy. The absorbing portion 55 may include a light absorbing material that absorbs the laser beam with the same material as the housing 53. For example, the absorbing portion 55 may include an oxide film having a high light absorption rate such as a core of a metallic material having a high thermal conductivity such as aluminum (Al) and the like and a black anodizing coated on the surface of the metallic material have.

The cooling portion 56 can be disposed closely to the absorption portion 55 to cool the heat energy emitted from the absorption portion 55. The cooling section 56 may contain ammonia, freon, methyl chloride, helium, liquid hydrogen, or distilled water as a refrigerant for cooling the heat energy.

Thus, the residual beam dump 50 can safely trap the laser beams Lr reflected from the object 30. Further, when the surface inspection is proceeded, the surface inspection can be performed stably without leaving the laser beams Lr around the object 30

3 is a view conceptually showing a beam dump of a surface inspection apparatus according to an embodiment of the present invention.

Referring to FIG. 3, the beam dump 20 can trap an unused laser beam when the surface inspection is not advanced. The beam dump 20 may include an outer member 22, a diffusion member 21, an absorbent member 23, and a cooling member 24.

The outer member 22 may include a hollow shape with one side opened. The laser beam L can be incident through the opening of the outer member 22. [ Here, the incident laser beam L may be a point-shaped laser beam. An absorbing member 23 may be formed inside the outer member 22. The absorptive member 23 may be formed integrally with the outer member 22.

The diffusion member 21 may be disposed to be coupled to the opening of the outer member 22. [ The diffusion member 21 can transmit the incident laser beam L and disperse the laser beam L into the inside of the outer member 22. [ The diffusion member 21 may include a light-transmitting material such as acrylic, quartz, and glass so that the laser beam L can be transmitted. The surface of the diffusion member 21 on which the laser beam L is incident has a smooth structure to facilitate the transmission of the beam. The surface of the diffusion member 21 dispersed in the outer member 22 has a rugged structure, . The uneven structure of the diffusion member 21 may include a structure having a roughness such as a glass sanded or a fly-eye lens. Accordingly, the beam dump 20 can be prevented from being damaged by dispersing a high-power laser beam L concentrated inside the beam dump 20. [

The absorbent member 23 may be disposed inside the outer member 22 in a triangular shape having an inclined surface. The absorbing member 23 can absorb the laser beam scattered from the diffusion member 21 and emit it as thermal energy. The absorbent member 23 and the outer member 22 may comprise a light absorbing material that absorbs the laser beam with the same material. For example, the absorptive member 23 and the outer frame member 22 may be made of a material having a high light absorptivity such as a core of a metallic material having a high thermal conductivity such as aluminum (Al) and a black anodizing coated on the surface of the metallic material And an oxide film.

The cooling member 24 can be disposed closely to the absorbent member 23 and the outer member 22 to cool the heat energy emitted from the absorbent member 23 and the outer member 22. [ The cooling member 24 may include ammonia, freon, methyl chloride, helium, liquid hydrogen, or distilled water as a refrigerant for cooling the thermal energy.

Accordingly, when the high-power laser beam is incident, the beam dump 20 can safely trap the laser beam dispersed therein.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood. It is therefore to be understood that the above-described embodiments are illustrative and not restrictive in every respect.

100 Surface inspection apparatus 10 Beam irradiation unit
15 reflective mirrors 20 beam dump
21, 54 diffusion member, diffusion portion 22, 53 outer member, housing
23, 55 absorbing member, diffusing portion 24, 56 cooling member, cooling portion
25 Shutter 30 Object
40 Imaging device 45 Optical element
50 Residual Beam Dump 51 Beam Collector
52 times total
L laser beam
Ls scattered laser beam
Lr Reflected laser beam

Claims (10)

An imaging device for detecting laser beams scattered from the object and analyzing a foreign substance when a line-shaped laser beam is incident on the object; And
And a residual beam dump for trapping laser beams of a page shape reflected from the object when a line-shaped laser beam is incident on the object. The method according to claim 1,
The residual beam dump,
A housing having an opening formed therein and forming an outer periphery;
A beam collector connected to the housing through the rotating body to collect the reflected laser beams;
A diffuser disposed at an opening of the housing to diffuse the collected laser beams into the housing;
An absorber disposed inside the housing in a triangular pyramid shape to absorb the dispersed laser beams; And
And a cooling unit disposed closely to the absorption unit and cooling the thermal energy of the absorption unit. 3. The method of claim 2,
The beam collector includes:
And a conversion angle for converting the collected laser beams into a parallel beam in a vertical direction,
And moves at the conversion angle through the rotating body. 3. The method of claim 2,
Wherein the beam collector includes a metal body or a mirror having a reflective surface with a high reflectance. 3. The method of claim 2,
Wherein the diffusing unit has a rugged structure in which the surface of the diffusing unit is dispersed into the housing through the collected laser beams. 3. The method of claim 2,
Wherein the diffusing portion comprises a light-transmitting material such as acrylic, quartz and glass. 3. The method of claim 2,
Wherein the absorber comprises a core of a metallic material having a high thermal conductivity and an oxide film having a high light absorptivity coated on the surface of the metallic material. The method according to claim 1,
A beam irradiating unit for irradiating a laser beam onto the object;
Reflection mirrors for changing the incident path of the laser beam irradiated from the beam irradiation unit; And
Further comprising a shutter for changing an incident path of the laser beam according to progress of the surface inspection. 9. The method of claim 8,
And a beam dump for trapping the laser beam when the surface inspection is not proceeded. 10. The method of claim 9,
In the beam dump,
A hollow outer member having one side opened;
A diffusion member that is coupled to the opening of the outer frame member and transmits the laser beam to disperse the laser beam into the outer frame member;
An absorbing member disposed inside the outer frame member in a triangular shape with an inclined surface, the absorbing member absorbing the dispersed laser beams; And
And a cooling member which is disposed closely to the absorber and the outer frame member and cools the thermal energy of the absorber and the outer frame member.

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