EP1807730A1

EP1807730A1 - Apparatus and method for inspecting edge defect and discoloration of glass substrate

Info

Publication number: EP1807730A1
Application number: EP06716128A
Authority: EP
Inventors: Soon-Jong Lee; Bong-Joo Woo
Original assignee: Semi Sysco Co Ltd
Current assignee: Semi Sysco Co Ltd
Priority date: 2005-03-02
Filing date: 2006-02-27
Publication date: 2007-07-18
Also published as: WO2006093381A1; CN101069118A; KR100642500B1; KR20060096717A; JP2008522213A; CN100523920C; JP4642858B2

Abstract

Provided are an apparatus and method for inspecting an edge defect and discoloration. The apparatus includes a loading unit for conveying a glass substrate used to manufacture a thin film transistor liquid crystal display; an inspection unit for inspecting edge defects and discoloration of the glass substrate conveyed by the loading unit; and a control unit for controlling the loading unit and the inspection unit. The edge defect and discoloration inspection apparatus is capable of automatically performing edge defect and discoloration inspection of a glass substrate during processes of manufacturing a thin film transistor liquid crystal display. In addition, it is possible to dispose the edge defect and discoloration inspection apparatus between deposition, etching and sputtering processes to confirm whether the glass substrate is good or bad in real time, thereby performing an economic and rapid process.

Description

APPARATUS AND METHOD FOR INSPECTING EDGE DEFECT AND DISCOLORATION OF GLASS SUBSTRATE

Technical Field

[1] The present invention relates to apparatus and method for inspecting an edge defect and discoloration of a glass substrate, and more particularly, to an apparatus and method for inspecting an edge defect and discoloration of a glass substrate for constituting a thin film transistor and a color filter in a thin film transistor liquid crystal display (TFT-LCD). Background Art

[2] Generally, a thin film transistor liquid crystal display is composed of a lower glass substrate, on which a thin film transistor is formed, an upper glass substrate, on which a color filter is formed, and liquid crystal injected between the lower glass substrate and the upper glass substrate.

[3] When defects such as cracks or edge breakage occur in the glass substrate for constituting the thin film transistor and the color filter, the entire glass substrate may be broken during processes of depositing the thin film transistor and the color filter on the glass substrate and etching the resultant structure.

[4] As a result, electrodes in a chamber, in which the processes are performed, may be damaged, or broken pieces of the glass substrate may be scattered to contaminate the interior of the chamber.

[5] In addition, when film deposition or etching is irregularly performed on the glass substrate, color represented through the thin film transistor liquid crystal display is changed, i.e., discoloration is generated, thereby producing bad products.

[6] Therefore, before performing deposition, etching, and sputtering processes using plasma after inserting the glass substrate into the chamber, the glass substrate should be inspected for edge defects, irregularities generated in the deposition, photolithography, or etching processes, and so on.

[7] For this, in a conventional art, a glass substrate edge inspection apparatus and a glass substrate discoloration inspection apparatus were provided separated from apparatuses used in manufacturing a thin film transistor liquid crystal display.

[8] However, the conventional glass substrate edge and discoloration inspection apparatuses are separated from the thin film transistor liquid crystal display manufacturing apparatus. As a result, whenever various processes are performed to manufacture the thin film transistor liquid crystal display, the edge and discoloration inspection of the glass substrate should be repeatedly and separately performed at separate places so that it is inconvenient and consumes unnecessary time. [9] In addition, since the discolor inspection apparatus irradiates a certain wavelength of light to the glass substrate to visually determine fringes represented by a surface of the glass substrate and a reflection angle of incident light, its determination result may vary depending on observer's subjectivity, thereby making precise inspection impossible. Disclosure of Invention

Technical Problem

[10] In order to solve the foregoing and/or other problems, it is an aspect of the present invention to provide edge defect and discoloration inspection apparatuses between continuous process apparatuses used to manufacture a thin film transistor liquid crystal display to continuously inspect edge defects and discoloration of a glass substrate in real time, and a method thereof. Technical Solution

[11] One aspect of the present invention provides an apparatus for inspecting an edge defect and discoloration, including: a loading unit for conveying a glass substrate used to manufacture a thin film transistor liquid crystal display; an inspection unit for inspecting edge defects and discoloration of the glass substrate conveyed by the loading unit; and a control unit for controlling the loading unit and the inspection unit.

[12] The edge inspection and the discoloration inspection of the glass substrate may be simultaneously performed.

[13] One of the edge inspection and the discoloration inspection of the glass substrate may be selectively performed.

[14] Further, the loading unit may include: a plate for receiving the glass substrate; and a conveyance member engaged with one side of the plate to pivot the plate.

[15] In addition, the inspection unit may include: an inspection frame having an inspection window through which the glass substrate passes; detection sensors installed at both sides of the inspection frame in a moving direction of the glass substrate to detect whether the substrate passes through the inspection window; a plurality of cameras installed at an upper part of the inspection window to inspect the edge of the glass substrate; and an illuminator installed at a lower part of the inspection window to radiate light onto the glass substrate passing through the inspection window.

[16] Further, a plurality of condensing lenses may be installed on the inspection frame to condense the light radiated from the illuminator and transmit the light to the control unit, and the control unit may include a spectroscope for analyzing the light condensed by the condensing lenses.

[17] Further, the spectroscope may have an observation wavelength of 180 ~ 1100 na nometers and a resolution of 0.1 ~ 10 nanometers.

[18] In addition, the plurality of cameras may be include a plurality of central cameras installed perpendicular to the glass substrate to inspect both edges of the glass substrate, initially and finally passing through the inspection window; and at least one pair of side cameras symmetrically disposed at both sides of the central cameras to inspect edge defects of both sides connecting both ends of the glass substrate.

[19] Further, the side cameras may be parallel to the central cameras.

[20] Furthermore, the side cameras may be inclined to the central cameras by a predetermined angle.

[21] In addition, the side camera may be a line scan charge coupled device (CCD) camera.

[22] Further, the control unit may include a monitor for displaying images photographed by the cameras.

[23] Furthermore, the loading unit and the inspection unit may be installed at at least one place of before an inlet gate valve and after an outlet gate valve of each process apparatus for manufacturing a thin film transistor liquid crystal display using plasma.

[24] Another aspect of the present invention provides a method of inspecting edge defects including: photographing a glass substrate using a camera; converting the photographed images to digital codes; mathematically comparing and calculating the digital codes and normal data; and alarming when the mathematically compared and calculated value is larger than an allowable range designated by a user.

[25] The normal data may be digital code-converted values of images photographed by the camera when a glass substrate having no edge defects passes through an edge defect inspection apparatus.

[26] Still another aspect of the present invention provides a method of inspecting discoloration including: condensing light radiated to a glass substrate using a condensing lens; analyzing a wavelength of the condensed light; comparing the analyzed wavelength with a normal level of wavelength; and alarming when the compared wavelength is larger than an allowable range designated by a user.

[27] The normal level of wavelength may be a wavelength received when a glass substrate, having no foreign substance and a normal thickness as a result measured by a thin film thickness measuring apparatus, passes through a discoloration inspection apparatus.

[28] Yet another aspect of the present invention provides a method of inspecting disco loration including: condensing light radiated to a glass substrate using a condensing lens; analyzing a wavelength of the condensed light; comparing the analyzed wavelength with the previously condensed and analyzed wavelength; and alarming when the compared wavelength is larger than an allowable range designated by a user. Brief Description of the Drawings

[29] The above and other aspects and advantages of the present invention will

[30] become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which:

[31] FIG. 1 is a side view of an edge defect and discoloration inspection apparatus in accordance with the present invention;

[32] FIG. 2 is a perspective view of an edge defect and discoloration inspection apparatus in accordance with a first embodiment of the present invention;

[33] FIGS. 3A to 3C are views showing an example of sequentially inspecting an edge of a glass substrate using an inspection unit of FIG. 1;

[34] FIG. 4 is a flowchart of an edge defect and discoloration inspection method using the apparatus of FIG. 2;

[35] FIG. 5 is a plan view of an edge defect and discoloration inspection apparatus in accordance with a second embodiment of the present invention;

[36] FIG. 6 is a flowchart of an edge defect and discoloration inspection method using the apparatus of FIG. 5; and

[37] FIG. 7 is a flowchart of another edge defect and discoloration inspection method using the apparatus of FIG. 5. Best Mode for Carrying Out the Invention

[38] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[39] FIG. 1 is a side view of an edge defect and discoloration inspection apparatus in accordance with the present invention, which is installed prior to a gate valve of deposition or etching equipment for manufacturing a thin film transistor liquid crystal display, and FIG. 2 is a perspective view of an edge defect and discoloration inspection apparatus in accordance with a first embodiment of the present invention.

[40] Referring to FIGS. 1 and 2, the edge defect and discoloration inspection apparatus is selectively installed before an inlet gate valve 52 or after an outlet gate valve (not shown) of process equipment 50 using plasma of deposition, etching and sputtering processes for manufacturing a thin film transistor liquid crystal display using plasma.

[41] The reason for this is that edge defects and discoloration of a glass substrate 40 are inspected before the glass substrate 40 enters a chamber 51 of various process equipment for deposition, etching and sputtering processes for manufacturing a thin film transistor liquid crystal display, or edge defects and discoloration of the glass substrate 40 discharged after the individual process is completed are inspected in real time to determine conveyance to the following process. [42] As shown in FIG. 2, the edge defect and discoloration inspection apparatus includes a loading unit 10, an inspection unit 20, and a control unit 30 so that edge defect and discoloration inspections are simultaneously performed, one of them is performed, or both inspections are sequentially performed with a time interval.

[43] The loading unit 10 includes a plate 11 for supporting the glass substrate 40, and a conveyance member 12 for moving the plate 11 to an appropriate position.

[44] The conveyance member 12 includes a plurality of rotating arms 12a, 12b, 12c and

12d sequentially engaged with each other to rotate by a predetermined angle. Specifically, one arm 12b of the plurality of rotating arms 12a, 12b, 12c and 12d is rotatably connected to another arm 12a just under the arm 12b at its one end and rotatably connected to another arm 12c just on the arm 12b at the other end, so that the conveyance member 12 drives the lowermost arm 12a through the uppermost arm 12d to be sequentially rotated from an initially overlapped state by a predetermined angle to thereby convey the glass substrate 40.

[45] The inspection unit 20 includes an inspection frame 26, detection sensors 24 for detecting the glass substrate 40, an illuminator 25, and a camera 22.

[46] An inspection window 21 is formed at the inspection frame 26 to pass the glass substrate 40 conveyed by the loading unit 10, and the detection sensors 24 are installed at both sides of the inspection frame 26 in a moving direction of the glass substrate 40.

[47] One detection sensor 24a of the detection sensors 24, at which the glass substrate 40 enters the inspection window 21, detects the time when the glass substrate 40 enters the inspection window 21 to transmit the time to the control unit 30 so that the camera 22 and the illuminator 25 start to operate. Then, the other detection sensor 24b of the detection sensors 24, at which the glass substrate 40 exits from the inspection window 21, detects non-existence of the glass substrate 40 in the inspection window 21 to the non-existence to the control unit 30 so that the camera 22 and the illuminator 25 stop to operate.

[48] The illuminator 25 is installed at a lower part of the inspection window 21 to radiate light onto the glass substrate 40 passing through the inspection window 21. In this process, the illuminator 25 may use a light emitting diode (LED), a laser diode, and so on.

[49] The cameras 22 function is to inspect edge defects and discoloration of the glass substrate 40 using light radiated from the illuminator 25. In order to easily determine whether the glass substrate 40 has the edge defects and discoloration, a plurality of central cameras 22a and side cameras 22b are installed at an upper part of the inspection window 21 as shown in FIG. 3 A to 3C. Here, the camera 22 may use charge-coupled device (CCD) camera with high resolution. In addition, the camera 22 can inspect the glass substrate 40 to a 5 mm position from an edge thereof, i.e., a part adjacent to the edge.

[50] The central cameras 22a inspect the edge defects and discoloration of both ends of the glass substrate 40 initially and finally passing through the inspection window 21 as shown in FIGS. 3A to 3C in a direction perpendicular to the glass substrate 40.

[51] At least one pair of side cameras 22b are symmetrically installed at both sides of the central camera 22a. The side cameras 22b are selectively installed at an upper part of the inspection window 21 in a direction parallel to or inclined to the central camera 22a in order to inspect edge defects and discoloration of side edges of the glass substrate 40, to which the central cameras 22a cannot inspect, i.e., the side edges connecting both ends of the glass substrate 400 inspected by the central cameras 22a. Here, the side cameras 22b may be rotatably hinged at the upper part of the inspection window 21 in a direction inclined to the central cameras 22a by a predetermined angle, so that the side cameras 22b can rotate by a predetermined angle to inspect the edges of the glass substrate 40 when it is difficult to inspect the edges of the glass substrate 40 due to excessive size of the glass substrate 40.

[52] Images photographed by the cameras 22 are converted into digital codes in real time to determine whether the glass substrate 40 is damaged or not.

[53] In addition, it is possible to determine through the input images whether a film deposited on the glass substrate 40 is damaged. Specifically, as shown in FIG. 4, images input after photographing the glass substrate (Sl) are converted into digital codes such as numbers (S2), and the digital codes are mathematically compared and calculated with the previously input normal data of the glass substrate 40 (S3). As a result of the comparison, when the difference is larger than an allowable range designated by a user (S4), the edge defects or discoloration can be alarmed to the user (S5). In this process, the normal data mean digital code conversion values of images photographed by the cameras when a glass substrate having no edge defects passes through the edge defect inspection apparatus.

[54] The control unit 30 includes a monitor 31 and a controller (not shown).

[55] The monitor 31 visually displays images photographed by the central and side cameras 22a and 22b.

[56] The controller controls an overall operation of the edge defect and discoloration apparatus 100, e.g., controls operations of the cameras 22 and the illuminator 25 after receiving the detected results from the detection sensors 24, converts the images photographed by the cameras 22 into digital codes, or mathematically calculates the digital codes.

[57] Hereinafter, operation of the edge defect and discoloration inspection apparatus 100 of the glass substrate 40 will be described in more detail.

[58] First, the glass substrate 40 is conveyed to an inspection window 21 of an inspection frame 26 using a loading unit 10. Then, a detection sensor 24a provided at the inspection frame 26, through which the glass substrate 40 enters, detects the glass substrate 40 to transmit the detected result to a control unit 30, and the control unit 30 operates cameras 22 and an illuminator 25 to photograph edges and discoloration of the glass substrate 40 to convert the photographed images into digital codes, thereby determining whether edge defects or discoloration exist through mathematical calculation. Next, when the glass substrate 40 is discharged through the inspection window 21, a detection sensor 24b provided at the inspection frame 26 determines non-existence of the glass substrate 40 to transmit the result to the control unit 30 so that the cameras 22 and the illuminator 25 stop to operate.

[59] The edge defect and discoloration inspection apparatus 100 is selectively installed before an inlet gate valve 52 or after an outlet gate valve (not shown) of process equipment 50 used in deposition, etching and sputtering processes to previously inspect edge defects and discoloration of the glass substrate 40 entering the deposition or etching process to prevent a bad glass substrate from entering a process chamber 51, or to inspect edge detect or discoloration of the glass substrate 40 discharged after the process completion to prevent the bad glass substrate from entering the following process.

[60] When the edge defects and discoloration of the glass substrate 40 discharged after the completion of the deposition or etching process are detected, it may be possible to recognize faults of the process equipment using plasma such as deposition, etching and sputtering apparatuses in real time. That is, when defects in the glass substrate discharged after the process completion are detected although there are no defects before entering the deposition, etching or sputtering process, it means that the process equipment has defects or problems.

[61] FIG. 5 is a plan view of an edge defect and discoloration inspection apparatus for explaining another method of inspecting discoloration of a glass substrate in accordance with a second embodiment of the present invention, and FIG. 6 is a flowchart of another edge defect and discoloration inspection method using the apparatus of FIG. 5.

[62] In this embodiment, the same reference numerals as shown in FIGS. 1 to 3 designate the same elements performing the same operation.

[63] Therefore, their descriptions will not be repeated.

[64] The edge defect and discoloration inspection apparatus 100 includes a loading unit

10, an inspection unit 20, and a control unit 30. A plurality of condensing lenses 23 are installed on an inspection frame 26 of the inspection unit 20. In addition, the control unit 30 includes a spectroscope (not shown).

[65] The condensing lenses 23 condense (SlO) light radiated to a glass substrate 40 from an illuminator 25 to transmit the light to the spectroscope 30. The spectroscope can observe a wavelength of 180 ~ 1100 nanometers, and has a resolution of 0.1 ~ 10 nanometers.

[66] Then, the spectroscope analyzes the wavelength of light condensed through the irregularly deposited glass substrate 40 (S20) to represent the result as an intensity level according to the wavelength of the condensed light. The intensity level of the glass substrate 40 having an irregular deposition portion 41 is compared with data of a normal level of glass substrate to obtain the difference (S30), and then, when the difference is larger than an allowable range designated by a user (S40), an alarm message is informed to the user (S50).

[67] FIG. 7 is a flowchart of another edge defect and discoloration inspection method using the apparatus of FIG. 5.

[68] Light radiated to a glass substrate 40 is condensed through condensing lenses 23

(SlOO), a wavelength of the condensed light is analyzed (S200), and data of the wavelength of light entering at each time is compared with data of the wavelength of the just previously condensed light (S300). When the difference is larger than an allowable range designated by a user (S400), an alarm message is informed to the user (S500).

[69] Therefore, the edge defect and discoloration inspection apparatus can be disposed between deposition and etching processes so that edge defects and discoloration are inspected in real time during continuous manufacturing processes of a thin film transistor liquid crystal display. Industrial Applicability

[70] As can be seen from the foregoing, an edge defect and discoloration inspection apparatus can automatically perform edge defect and discoloration inspection of a glass substrate during processes of manufacturing a thin film transistor liquid crystal display. In addition, it is possible to dispose the edge defect and discoloration inspection apparatus between deposition, etching and sputtering processes to confirm whether the glass substrate is good or bad in real time, thereby performing an economic and rapid process.

[71] The forgoing description concerns an exemplary embodiment of the invention, is intended to be illustrative, and should not be construed as limiting the invention. Many alternatives, modifications, and variations within the scope and spirit of the present invention will be apparent to those skilled in the art.

Claims

[1] An apparatus for inspecting an edge defect and discoloration, comprising: a loading unit for conveying a glass substrate used to manufacture a thin film transistor liquid crystal display; an inspection unit for inspecting edge defects and discoloration of the glass substrate conveyed by the loading unit; and a control unit for controlling the loading unit and the inspection unit.

[2] The apparatus according to claim 1, wherein the edge inspection and the discoloration inspection of the glass substrate are simultaneously performed.

[3] The apparatus according to claim 1, wherein one of the edge inspection and the discoloration inspection of the glass substrate is selectively performed.

[4] The apparatus according to claim 1, wherein the loading unit comprises: a plate for receiving the glass substrate; and a conveyance member engaged with one side of the plate to pivot the plate.

[5] The apparatus according to claim 1, wherein the inspection unit comprises: an inspection frame having an inspection window through which the glass substrate passes; detection sensors installed at both sides of the inspection frame in a moving direction of the glass substrate to detect whether the glass substrate passes through the inspection window; a plurality of cameras installed at an upper part of the inspection window to inspect the edge of the glass substrate; and an illuminator installed at a lower part of the inspection window to radiate light onto the glass substrate passing through the inspection window.

[6] The apparatus according to claim 5, wherein a plurality of condensing lenses are installed on the inspection frame to condense the light radiated from the illuminator and transmit the light to the control unit.

[7] The apparatus according to claim 1 or 5, wherein the control unit comprises a spectroscope for analyzing the light condensed by the condensing lenses.

[8] The apparatus according to claim 6, wherein the spectroscope has an observation wavelength of 180 ~ 1100 nanometers and a resolution of 0.1 ~ 10 nanometers.

[9] The apparatus according to claim 5, wherein the plurality of cameras include a plurality of central cameras installed perpendicular to the glass substrate to inspect both edges of the glass substrate, initially and finally passing through the inspection window; and at least one pair of side cameras symmetrically disposed at both sides of the central cameras to inspect edge defects of both sides connecting both ends of the glass substrate.

[10] The apparatus according to claim 9, wherein the side cameras are parallel to the central cameras.

[11] The apparatus according to claim 9, wherein the side cameras are inclined to the central cameras by a predetermined angle.

[12] . The apparatus according to claim 9, wherein the side camera is a line scan charge coupled device (CCD) camera.

[13] The apparatus according to claim 1, wherein the control unit comprises a monitor for displaying images photographed by the cameras.

[14] The apparatus according to claim 1, wherein the loading unit and the inspection unit are installed at at least one place of before an inlet gate valve and after an outlet gate valve of each process apparatus for manufacturing a thin film transistor liquid crystal display using plasma.

[15] A method of inspecting edge defects, comprising: photographing a glass substrate passing through an inspection window using a camera; converting the photographed images to digital codes; mathematically comparing and calculating the digital codes and normal data; and alarming when the mathematically compared and calculated value is larger than an allowable range designated by a user.

[16] The method according to claim 15, wherein the normal data are digital code- converted values of images photographed by the camera when a glass substrate having no edge defect passes through an edge defect inspection apparatus. [17] The method according to claim 15, wherein the image photographed by the camera comprises edges of both ends of the glass substrate initially and finally passing through the inspection window, and edges of both sides of the glass substrate connecting both ends of the glass substrate. [18] The method according to claim 17, wherein the edges of both sides connecting both ends of the glass substrate are photographed using a line scan method. [19] The method according to claim 15, wherein photographing the glass substrate further comprises displaying the photographed image through a monitor. [20] A method of inspecting discoloration, comprising: condensing light radiated to a glass substrate using a condensing lens; analyzing a wavelength of the condensed light; comparing the analyzed wavelength with a normal level of wavelength; and alarming when the compared wavelength is larger than an allowable range designated by a user. [21] The method according to claim 20, wherein the normal level of wavelength is a wavelength received when a glass substrate, having no foreign substances and a normal thickness as a result measured by a thin film thickness measuring apparatus, passes through a discoloration inspection apparatus. [22] The method according to claim 20, wherein the wavelength of the condensed light is analyzed through a spectroscope. [23] The method according to claim 22, wherein the wavelength analyzed through the spectroscope is represented as an intensity level. [24] A method of inspecting discoloration, comprising: condensing light radiated to a glass substrate using a condensing lens; analyzing a wavelength of the condensed light; comparing the analyzed wavelength and the previously condensed with analyzed wavelength; and alarming when the compared wavelength is larger than an allowable range designated by a user.