Flatness measuring device for the tested object

Abstract

A flatness measuring device for an object under test is provided, comprising: a laser source disposed above the object under test and generating laser light having a wavelength that can be reflected from the object under test; an etalon interferometer disposed between the object under test and the laser source and converting the laser light into a laser array that illuminates the object under test; and an analysis unit disposed above the object under test and measuring the flatness of the object under test using the laser array reflected from the object under test. Therefore, the flatness of an object under test, such as a glass substrate, can be precisely measured, thereby reducing process defects in display devices through compensation for the flatness of the glass substrate.

Description

Technical Field

[0001] The present invention relates to a method for measuring the flatness of an object under test and an apparatus for performing the flatness measurement method, and more specifically, to a method for measuring the surface flatness of a glass substrate and an apparatus for performing the method. Background Technology

[0002] For glass substrates primarily used in display devices, excellent flatness is required. If the glass substrate has low flatness, the various films to be formed on its surface may also have uneven thickness. Films with uneven thickness may cause process defects.

[0003] Therefore, there is a need for a method and apparatus for precisely measuring the flatness of a glass substrate and a film formed on the surface of the glass substrate. Summary of the Invention

[0004] The present invention provides a method for precisely measuring the flatness of a test object, such as a glass substrate.

[0005] Furthermore, the present invention also provides an apparatus for performing the method.

[0006] According to one aspect of the present invention, a method for measuring the flatness of a test object can be used to convert a laser having a wavelength that can be reflected from the test object into a laser array. The laser array can be irradiated onto the test object. The flatness of the test object can be measured using the laser array reflected from the test object.

[0007] In various exemplary embodiments, measuring the flatness of the object under test may include: measuring the reflectivity corresponding to various locations of the object under test using the laser array reflected from the object under test; and obtaining the thickness corresponding to various locations of the object under test from the reflectivity.

[0008] In various exemplary embodiments, the measurement of the flatness of the object under test may include: using the laser array reflected from the object under test to measure the stress corresponding to various positions of the object under test caused by the deformation of the object under test.

[0009] In various exemplary embodiments, the method may further include: comparing the stress corresponding to each position of the tested object with the stress corresponding to each position of a reference tested object, thereby obtaining the actual stress corresponding to each position of the tested object.

[0010] In various exemplary embodiments, the method may further include filtering the laser before converting the laser into the laser array.

[0011] In various exemplary embodiments, the object to be detected may include a glass substrate or at least one film formed on the glass substrate.

[0012] Another aspect of the present invention relates to a flatness measuring device for a test object, which may include a laser source, an etalon interferometer, and an analysis unit. The laser source may be disposed above the test object and generates laser light having a wavelength that can be reflected from the test object. The etalon interferometer may be disposed between the test object and the laser source and converts the laser light into a laser array that illuminates the test object. The analysis unit may be disposed above the test object and measures the flatness of the test object using the laser array reflected from the test object.

[0013] In various exemplary embodiments, the laser source may be configured in a first vertical direction and a second vertical direction and generate the laser along the second vertical direction, wherein the first vertical direction passes perpendicularly through the object being detected, and the second vertical direction is parallel to the first vertical direction at other locations on the plane.

[0014] In various exemplary embodiments, the flatness measuring device may further include: a beam splitter disposed between the etalon interferometer and the object being tested, and guiding the laser array from the second vertical direction to the first vertical direction.

[0015] In various exemplary embodiments, the analysis unit may be located in the first vertical direction.

[0016] In various exemplary embodiments, the flatness measuring device may further include a filter disposed between the laser source and the etalon interferometer, for filtering the laser.

[0017] In various exemplary embodiments, the laser source may be configured at a position inclined to the surface of the object being tested along a first direction. The analysis unit may be configured at a position inclined along a second direction opposite to the first direction.

[0018] In various exemplary embodiments, the analysis unit may utilize the laser array reflected from the object being tested to measure the reflectivity corresponding to various locations of the object being tested. The analysis unit may obtain the thickness corresponding to various locations of the object being tested from the reflectivity.

[0019] In various exemplary embodiments, the analysis unit may use the laser array reflected from the object under test to measure the stress corresponding to each position of the object under test caused by the deformation of the object under test.

[0020] In each exemplary embodiment, the analysis unit can compare the stress corresponding to each position of the tested object with the stress corresponding to each position of a reference tested object, thereby obtaining the actual stress corresponding to each position of the tested object.

[0021] In various exemplary embodiments, the analysis unit may include: an optical sensor that receives the laser array reflected from the object being detected.

[0022] In various exemplary embodiments, the object to be detected may include a glass substrate or at least one film formed on the glass substrate.

[0023] Another aspect of the present invention relates to a flatness measuring apparatus for a glass substrate, which may include a laser source, an etalon interferometer, a beam splitter, and an analysis unit. The laser source may be disposed on the upper part of the glass substrate in a first vertical direction perpendicular to the surface of the glass substrate and in a second vertical direction parallel to the first vertical direction at other locations in a plane, and generates laser light along the second vertical direction having a wavelength that can be reflected from the glass substrate. The etalon interferometer may be disposed between the laser source and the glass substrate in the second vertical direction, and converts the laser light into a laser array. The beam splitter may be disposed between the etalon interferometer and the glass substrate, and guides the laser array from the second vertical direction to the first vertical direction. The analysis unit may be disposed on the upper part of the glass substrate in the first vertical direction, receives the laser array reflected from the glass substrate, and uses the received laser array to measure the flatness of the glass substrate.

[0024] In various exemplary embodiments, the flatness measuring device may further include a filter disposed between the laser source and the etalon interferometer, for filtering the laser.

[0025] In various exemplary embodiments, the analysis unit may use the laser array reflected from the glass substrate to measure the stress and reflectivity corresponding to various locations on the glass substrate caused by deformation of the glass substrate, and obtain the thickness corresponding to each location on the glass substrate from the reflectivity. The analysis unit may compare the stress corresponding to each location on the glass substrate with the stress corresponding to each location on a reference glass substrate to obtain the actual stress corresponding to each location on the glass substrate.

[0026] (Invention Effects)

[0027] According to the present invention, a laser having a wavelength that can be reflected from the material of the test object can be irradiated onto the test object, and the flatness of the test object can be measured using an array of lasers reflected from the test object. The reflectivity and stress corresponding to various locations on the test object can be measured using the laser array reflected from the test object, thereby obtaining the thickness corresponding to each location on the test object. In particular, flatness and thickness deviation can be obtained simultaneously from the stress measured at the same location on the test object (e.g., the same location where deformation has occurred). Therefore, the flatness of the test object, such as a glass substrate, can be precisely measured, and process defects in the display device can be reduced by compensating for the flatness of the glass substrate. Attached Figure Description

[0028] Figure 1 This is a diagram illustrating a flatness measuring device for an object to be tested according to an embodiment of the present invention.

[0029] Figure 2 It is shown by Figure 1 The diagram shows the laser array analyzed by the analysis unit of the measuring device.

[0030] Figures 3 to 5 This is a graph showing the reflectivity of laser light in relation to the flatness of the glass substrate.

[0031] Figure 6 It is shown by Figure 1 The diagram shows the stress distribution on the glass substrate as measured by the measuring device shown.

[0032] Figure 7 This is a diagram showing the stress distribution on a reference glass substrate.

[0033] Figure 8 It shows from Figure 6 and Figure 7 The stress distribution shown is a graph of the actual stress at various locations on the glass substrate.

[0034] Figures 9 to 15 This shows that it can be applied. Figure 1 Diagrams of various objects being measured using the measuring device shown.

[0035] Figure 16 It shows the use of in sequence. Figure 1 The flowchart shows a method for measuring the flatness of a glass substrate using the measuring device shown.

[0036] Figure 17 This is a diagram illustrating a flatness measuring device for a test object according to other embodiments of the present invention.

[0037] Figure 18 This is a diagram illustrating a flatness measuring device for a test object according to another embodiment of the present invention.

[0038] Symbol explanation:

[0039] 110, 210, 310: Laser source; 120, 220: Filter; 130, 230: Ego interferometer; 132, 232: First etalon; 134, 234: Second etalon; 140, 340: Beam splitter; 142: First splitter; 144: Second splitter; 150, 250, 350: Analysis unit; 360: Objective lens. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0041] This invention can have various modifications and forms, with specific embodiments illustrated in the accompanying drawings and described in detail in the text. However, this is not to limit the invention to the specific disclosed forms, but should be understood to include all modifications, equivalents, and substitutions encompassed within the spirit and scope of the invention. Similar reference numerals are used for similar constituent elements in the description of the various drawings.

[0042] The terms "first," "second," etc., can be used to describe various constituent elements, but the constituent elements described should not be limited to these terms. These terms are used only for the purpose of distinguishing one constituent element from another. For example, without departing from the scope of this invention, a first constituent element can be named a second constituent element, and similarly, a second constituent element can be named a first constituent element.

[0043] The terminology used in this application is for illustrative purposes only and is not intended to limit the invention. Singular expressions include multiple expressions unless explicitly stated otherwise. In this application, terms such as "comprising" or "having" should be understood as referring to the presence of features, numbers, steps, operations, constituent elements, components, or combinations thereof described in the specification, and do not preclude the existence or additional possibilities of one or more other features, numbers, steps, operations, constituent elements, components, or combinations thereof.

[0044] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) shall have the same meaning as commonly understood by those skilled in the art. Furthermore, terms defined in commonly used dictionaries shall be interpreted as having a meaning consistent with the relevant technical context, and shall not be construed as having an idealized or overly formal meaning unless expressly defined in this application.

[0045] Figure 1 This is a diagram illustrating a flatness measuring device for an object to be tested according to an embodiment of the present invention.

[0046] Reference Figure 1 The flatness measuring device (hereinafter referred to as the measuring device) 100 of the tested object involved in this embodiment may include a laser source 110, a filter 120, an etalon interferometer 130, a beam splitter 140, and an analysis unit 150.

[0047] The measuring device 100 of this embodiment can be applied to a glass substrate 10, which is one example of the object being tested. In particular, the glass substrate 10 can be a bare glass substrate 10 on which no film is formed. The measuring device 100 can measure the thickness at various positions of the glass substrate 10 to obtain the flatness of the glass substrate 10. The glass substrate 10 can be arranged horizontally. The first vertical direction can be a direction that passes through the upper surface of the glass substrate 10 and is orthogonal to the upper surface of the glass substrate 10. That is, the first vertical direction can be a direction that passes perpendicularly through the glass substrate 10.

[0048] A laser source 110 may be disposed on the upper part of the glass substrate 10. In this embodiment, the laser source 110 may be located in a second vertical direction. The second vertical direction may be a direction parallel to the first vertical direction but not passing through the upper surface of the glass substrate 10. The laser source 110 may generate laser light L0 downward toward the glass substrate 10 along the second vertical direction. In particular, the laser light L0 may have a wavelength selected according to the material of the object being detected. For example, the laser light L0 may have a wavelength that can be reflected from the object being detected. Since the object being detected in this embodiment is the glass substrate 10, the laser source 110 may generate laser light L0 having a wavelength that can be reflected from glass, which is the material of the glass substrate 10.

[0049] The filter 120 can be disposed in a second vertical direction between the laser source 110 and the glass substrate 10. The filter 120 can filter the laser L0 generated from the laser source 110, thereby removing noise contained in the laser L0. Thus, the laser L0 passing through the filter 120 can be transformed into a filtered laser L1.

[0050] The etalon interferometer 130 can be disposed between the filter 120 and the glass substrate 10 in a second vertical direction. The etalon interferometer 130 can transform the filtered laser L1 into laser arrays L21 and L22. The laser arrays L21 and L22 can have a structure in which at least two lasers are arranged. That is, the laser arrays L21 and L22 in this embodiment can have a structure in which two lasers are arranged.

[0051] For example, if the filtered laser L1 passes through the etalon interferometer 130, the filtered laser L1 can be separated along two mutually orthogonal directions, thereby being transformed into laser arrays L21 and L22. The laser arrays L21 and L22 transformed by the etalon interferometer 130 can have two-dimensional or three-dimensional structures. Furthermore, the laser arrays L21 and L22 transformed by the etalon interferometer 130 can have parallel or tilted structures.

[0052] The etalon interferometer 130 may include a first etalon 132 and a second etalon 134. The first etalon 132 may be disposed below the filter 120 in a second vertical direction. The second etalon 134 may be disposed below the first etalon 132 in the second vertical direction.

[0053] Beam splitter 140 can guide the laser arrays L21 and L22 formed by etalon interferometer 130 to the upper surface of glass substrate 10. That is, beam splitter 140 can guide the laser arrays L21 and L22 located in the second vertical direction to the first vertical direction. Beam splitter 140 may include a first splitter 142 and a second splitter 144.

[0054] The first separator 142 may be disposed below the second etalon 134 in the second vertical direction. Furthermore, the first separator 142 may be disposed at an angle to the second vertical direction. The first separator 142 may reflect the laser arrays L21 and L22 located in the second vertical direction along the horizontal direction toward the first vertical direction.

[0055] The second separator 144 can be disposed on the upper part of the glass substrate 10 in the first vertical direction. The second separator 144 can be disposed at an angle to the first vertical direction. In particular, the second separator 144 can be located at the same height as the first separator 142. As another embodiment, the second separator 144 can also be disposed at a position higher or lower than the first separator 142. Therefore, the laser arrays L21 and L22 reflected by the first separator 142 can be incident on the second separator 144. The second separator 144 can reflect the laser arrays L21 and L22 towards the upper surface of the glass substrate 10 along the first vertical direction. Therefore, the laser arrays L21 and L22 can be incident vertically on the upper surface of the glass substrate 10.

[0056] The analysis unit 150 may be disposed on the upper part of the glass substrate 10 in a first vertical direction. In particular, the analysis unit 150 may be located on the upper part of the second separator 144. The analysis unit 150 may receive laser arrays R1 and R2 reflected from the upper surface of the glass substrate 10. Therefore, the analysis unit 150 may include an optical sensor for receiving laser arrays R1 and R2.

[0057] In other embodiments, the analysis unit 150 may not be located in the first vertical direction. For example, the analysis unit 150 may be located in the second vertical direction. Furthermore, when the glass substrate 10 has a large area, the laser light source 110, filter 120, etalon interferometer 130, and first separator 142 may also be located in the first vertical direction. In this case, the second vertical direction may be a direction that passes through the glass substrate 10 and is parallel to the first vertical direction at other locations on the plane.

[0058] Additionally, the measuring device 100 may include independent optical components such as a separator and a mirror.

[0059] Figure 2 It is shown by Figure 1 The diagram shows the laser array analyzed by the analysis unit of the measuring device.

[0060] Reference Figure 2 The laser arrays R1 and R2 received by the analysis unit 150 may have a 2×2 matrix configuration. However, the laser arrays R1 and R2 received by the analysis unit 150 may also have a matrix configuration of 3×3 or more. The laser arrays R1 and R2 may be located within an irradiation area S. The irradiation area S may correspond to a certain position on the glass substrate 10 into which the laser arrays L21 and L22 are incident.

[0061] The glass substrate 10 or the film formed on the glass substrate 10 may have a thickness distribution. This thickness distribution may arise from factors such as the size and location of the target on the glass substrate 10 or the film, and the applicable location of processes such as sputtering or chemical vapor deposition (CVD) on the glass substrate 10 or the film. Furthermore, due to the material and / or warpage of the glass substrate 10 or the film after sputtering, CVD, or similar processes, different stresses may occur at different locations on the glass substrate 10 or the film.

[0062] The analysis unit 150 can use laser arrays R1 and R2 to measure the reflectivity corresponding to each position of the glass substrate 10. Furthermore, the analysis unit 150 can obtain the thickness corresponding to each position of the glass substrate 10 from the reflectivity. In particular, the analysis unit 150 can use laser arrays R1 and R2 to measure the stress corresponding to each position of the glass substrate 10. Regarding the stress corresponding to each position of the glass substrate 10, due to the material of the glass substrate 10 and / or deformation caused by warping, different stresses may occur at different positions of the glass substrate 10. In particular, the analysis unit 150 can compare the stress corresponding to each position of the glass substrate 10 with the stress corresponding to each position of a reference glass substrate to obtain the actual stress corresponding to each position of the glass substrate 10. For example, the analysis unit 150 can subtract the stress corresponding to each position of the reference glass substrate from the stress corresponding to each position of the glass substrate 10 to obtain the actual stress corresponding to each position of the glass substrate 10. Here, the reference glass substrate may have a flat surface without any bending.

[0063] For example, such as Figure 3 As shown, if the laser arrays R1 and R2 reflected from a certain position on the surface of the glass substrate 10 travel in a direction parallel to the incident direction of the laser arrays L21 and L22 incident on the glass substrate 10, the analysis unit 150 will analyze the laser arrays R1 and R2 and interpret them as indicating that the corresponding position of the glass substrate 10 has a flat surface. Furthermore, since the corresponding position of the glass substrate 10 has a flat surface, the stress at the corresponding position of the glass substrate 10 measured by the analysis unit 150 will be substantially the same as the stress at the corresponding position of the reference glass substrate.

[0064] On the contrary, such as Figure 4 As shown, if the laser arrays R1 and R2 reflected from a certain position on the surface of the glass substrate 10 travel in a direction inclined inward toward the incident direction of the laser arrays L21 and L22 incident on the glass substrate 10, the analysis unit 150 will analyze the laser arrays R1 and R2 and interpret them as indicating that the corresponding position of the glass substrate 10 has a downwardly curved surface. Furthermore, since the corresponding position of the glass substrate 10 has a downwardly curved surface, the stress at the corresponding position of the glass substrate 10 measured by the analysis unit 150 will differ from the stress at the corresponding position of the reference glass substrate. That is, tensile stress may be generated on the downwardly curved surface of the glass substrate 10.

[0065] In addition, such as Figure 5As shown, if the laser arrays R1 and R2 reflected from a certain position on the surface of the glass substrate 10 travel in a direction inclined outward toward the incident direction of the laser arrays L21 and L22 incident on the glass substrate 10, the analysis unit 150 will analyze the laser arrays R1 and R2 and interpret them as indicating that the corresponding position of the glass substrate 10 has an upwardly curved surface. Furthermore, since the corresponding position of the glass substrate 10 has an upwardly curved surface, the stress at the corresponding position of the glass substrate 10 measured by the analysis unit 150 will differ from the stress at the corresponding position of the reference glass substrate. That is, compressive stress may be generated on the upwardly curved surface of the glass substrate 10.

[0066] As described above, the glass substrate 10 or the film may have uneven flatness due to local deformation. Uneven flatness may cause stresses including thickness distribution of the glass substrate 10 itself or the film thickness distribution and / or material and thermally related warpage deformation of the glass substrate 10 or the film. In order to remove noise caused by thickness distribution of the glass substrate 10 itself or the film thickness distribution, the analysis unit 150 can simultaneously obtain flatness and thickness deviation from the stress measured at the same location on the glass substrate 10 or the film (e.g., the same location where deformation occurred).

[0067] Figure 6 It is shown by Figure 1 The diagram shows the stress distribution on the glass substrate measured by the measuring device shown. Figure 7 It is a diagram showing the stress distribution of a reference glass substrate, and Figure 8 It shows from Figure 6 and Figure 7 The stress distribution shown is a graph of the actual stress at various locations on the glass substrate.

[0068] like Figure 6 As shown, the analysis unit 150 can analyze the laser arrays R1 and R2 reflected from the glass substrate 10, thereby measuring the stress corresponding to each position of the glass substrate 10.

[0069] Figure 7 The stress of the reference glass substrate with a flat surface shown can be input to the analysis unit 150.

[0070] Analysis Department 150 Comparable Figure 6 The stresses corresponding to various positions on the glass substrate 10 are shown. Figure 7 The stress corresponding to each position on the reference glass substrate is shown, thereby obtaining... Figure 8 The actual stress corresponding to each position on the glass substrate 10 is shown. For example, the analysis unit 150 can analyze the stress from... Figure 6 The stress subtraction corresponding to each position of the glass substrate 10 shown is... Figure 7The stress corresponding to each position on the reference glass substrate is shown, thereby obtaining... Figure 8 The actual stresses corresponding to various positions on the glass substrate 10 are shown.

[0071] Figures 9 to 15 It shows that it is applicable Figure 1 Diagrams of various objects being measured using the measuring device shown.

[0072] Reference Figure 9 , Figure 1 The measuring device 100 shown can be applied to a polysilicon layer 11 formed on the surface of a glass substrate 10 to measure the flatness of the polysilicon layer 11. In particular, the laser source 110 can generate laser light with a wavelength that can be reflected from the polysilicon material of the polysilicon layer 11.

[0073] Reference Figure 10 , Figure 1 The measuring device 100 shown is suitable for measuring... Figure 9 A crystalline polycrystalline silicon layer 12 is formed by crystallizing a polycrystalline silicon layer 11, thereby measuring the flatness of the crystalline polycrystalline silicon layer 12. In particular, the laser source 110 can generate laser light with a wavelength that can be reflected from the crystalline polycrystalline silicon material of the crystalline polycrystalline silicon layer 12.

[0074] Reference Figure 11 , Figure 1 The measuring device 100 shown can be used in Figure 10 An active layer 13 is formed on a crystalline polycrystalline silicon layer 12, thereby measuring the flatness of the active layer 13. In particular, a laser source 110 can generate laser light with a wavelength that can be reflected from the material of the active layer 13.

[0075] Reference Figure 12 , Figure 1 The measuring device 100 shown is suitable for measuring... Figure 11 An active pattern 14 is formed by patterning the active layer 13, thereby measuring the flatness of the active pattern 14. In particular, the laser source 110 can generate laser light with a wavelength that can be reflected from the material of the active pattern 14.

[0076] Reference Figure 13 , Figure 1 The measuring device 100 shown can be used in Figure 12 An insulating layer 15 is formed on the active pattern 14 to measure the flatness of the insulating layer 15. In particular, a laser source 110 can generate laser light with a wavelength that can be reflected from the material of the insulating layer 15.

[0077] Reference Figure 14 , Figure 1 The measuring device 100 shown can be used in Figure 13 A gate layer 16 is formed on the insulating layer 15, thereby measuring the flatness of the gate layer 16. In particular, the laser source 110 can generate laser light with a wavelength that can be reflected from the material of the gate layer 16.

[0078] Reference Figure 15 , Figure 1 The measuring device 100 shown can be used in Figure 14 A photoresist pattern 17 is formed on the gate layer 16, thereby measuring the flatness of the photoresist pattern 17. In particular, the laser source 110 can generate laser light with a wavelength that can be reflected from the material of the photoresist pattern 17.

[0079] Figure 16 It shows the use of in sequence. Figure 1 The flowchart shows a method for measuring the flatness of a glass substrate using the measuring device shown.

[0080] Reference Figure 1 and Figure 16 In step ST300, the laser source 110 can generate a laser L0 having a wavelength that can be reflected from the glass substrate 10.

[0081] In step ST310, filter 120 filters the laser L0, thereby removing noise contained within the laser L0. Thus, the laser L0 passing through filter 120 can be transformed into a filtered laser L1.

[0082] In step ST320, the etalon interferometer 130 can transform the filtered laser L1 into laser arrays L21 and L22.

[0083] In step ST330, the beam splitter 140 guides the laser arrays L21 and L22 formed by the etalon interferometer 130 to the upper surface of the glass substrate 10. Specifically, the first splitter 142 reflects the laser arrays L21 and L22 located in the second vertical direction along the horizontal direction toward the first vertical direction. The second splitter 144 reflects the laser arrays L21 and L22 along the first vertical direction toward the upper surface of the glass substrate 10. Therefore, the laser arrays L21 and L22 can be incident perpendicularly onto the upper surface of the glass substrate 10.

[0084] In step ST340, the analysis unit 150 can receive laser arrays R1 and R2 reflected from the upper surface of the glass substrate 10. The analysis unit 150 can use the laser arrays R1 and R2 to measure the reflectivity corresponding to each position of the glass substrate 10. Furthermore, the analysis unit 150 can obtain the thickness corresponding to each position of the glass substrate 10 from the reflectivity. In particular, the analysis unit 150 can use the laser arrays R1 and R2 to measure the stress corresponding to each position of the glass substrate 10. Specifically, the analysis unit 150 can compare the stress corresponding to each position of the glass substrate 10 with the stress corresponding to each position of a reference glass substrate to obtain the actual stress corresponding to each position of the glass substrate 10. For example, the analysis unit 150 can measure the reflectivity from the laser arrays R1 and R2. Figure 6 The stress subtraction corresponding to each position of the glass substrate 10 shown is... Figure 7 The stress corresponding to each position on the reference glass substrate is shown, thereby obtaining... Figure 8 The actual stresses corresponding to various positions on the glass substrate 10 are shown.

[0085] Figure 17 This is a diagram illustrating a flatness measuring device for a test object according to other embodiments of the present invention.

[0086] Reference Figure 17 The flatness measuring device 200 of the tested object involved in this embodiment may include a laser light source 210, a filter 220, a standard interferometer 230, and an analysis unit 250.

[0087] The laser source 210 can be tilted and disposed on the upper part of the glass substrate 10. Therefore, the laser source 210 can generate laser L0 along the direction tilted to the upper surface of the glass substrate 10.

[0088] A filter 220 may be disposed between the laser source 210 and the glass substrate 10. The filter 220 filters the laser L0 generated by the laser source 210, thereby removing noise contained within the laser L0. Therefore, the laser L0 passing through the filter 220 can be converted into a filtered laser L1. The filter 220 may have the same characteristics as... Figure 1 The filter 120 shown has essentially the same function.

[0089] An etalon interferometer 230 can be configured between the filter 220 and the glass substrate 10. The etalon interferometer 230 can transform the filtered laser L1 into laser arrays L21 and L22. The etalon interferometer 230 can have... Figure 1 The etalon interferometer 130 shown has essentially the same function. The laser arrays L21 and L22 of the etalon interferometer 230 can be incident obliquely onto the upper surface of the glass substrate 10.

[0090] The analysis unit 250 can be tilted and disposed on the upper part of the glass substrate 10. The analysis unit 250 can receive laser arrays R1 and R2 reflected from the upper surface of the glass substrate 10, thereby measuring the flatness of the glass substrate 10. The analysis unit 250 may have... Figure 1 The analysis unit 150 shown has essentially the same function.

[0091] Figure 18 This is a diagram illustrating a flatness measuring device for a test object according to another embodiment of the present invention.

[0092] Reference Figure 18 The flatness measuring device 300 of the tested object involved in this embodiment may include a laser light source 310, a beam splitter 340, an objective lens 360, and an analysis unit 350.

[0093] The laser source 310 may be disposed on one side of the upper portion of the glass substrate 10. That is, the laser source 310 may be disposed at a position detached from a first vertical direction orthogonal to the upper surface of the glass substrate 10. In other words, the laser source 310 may not be located in the first vertical direction. Specifically, the laser source 310 may be disposed in a direction parallel to the upper surface of the glass substrate 10 (i.e., a horizontal direction substantially orthogonal to the first vertical direction). Therefore, the laser source 310 may generate laser light along the horizontal direction. As another embodiment, the laser source 310 may also be located on the upper portion of the glass substrate 10 in the first vertical direction.

[0094] The beam splitter 340 may be disposed on the upper part of the glass substrate 10. In particular, the beam splitter 340 may be located in a first vertical direction. Laser light irradiated from the laser source 310 along the horizontal direction may be guided by the beam splitter 340 toward the upper surface of the glass substrate 10 to the lower part.

[0095] Objective lens 360 can be disposed between beam splitter 340 and glass substrate 10. Objective lens 360 can focus the laser guided by beam splitter 340 onto the upper surface of glass substrate 10. Therefore, objective lens 360 can have a reflective function.

[0096] The analysis unit 350 may be disposed on the upper part of the glass substrate 10. In particular, the analysis unit 350 may be located in a first vertical direction. The analysis unit 350 may receive a laser array reflected from the upper surface of the glass substrate 10, thereby measuring the flatness of the glass substrate 10. The analysis unit 350 may have [a certain feature]. Figure 1 The analysis unit 350 shown has essentially the same function.

[0097] According to this embodiment, a laser having a wavelength corresponding to the material of the object being tested can be irradiated onto the object, and the flatness of the object can be measured using a laser array reflected from the object. Furthermore, the reflectivity and stress corresponding to various locations on the object can be measured using the laser array reflected from the object, thereby obtaining the thickness corresponding to each location on the object. In particular, flatness and thickness deviation can be obtained simultaneously from the stress measured at the same location on the object (e.g., the same location where deformation has occurred). Therefore, the flatness of an object being tested, such as a glass substrate, can be precisely measured, thereby reducing process defects in the display device through compensation for the flatness of the glass substrate.

[0098] (Industry availability)

[0099] This invention is applicable to glass substrates used in organic light-emitting display devices and various electronic devices including them, as well as at least one film formed on the glass substrate. For example, this invention is applicable to mobile phones, smartphones, video phones, smart tablets, smartwatches, desktop PCs, vehicle navigation systems, televisions, computer monitors, laptops, head-mounted displays, etc.

[0100] The present invention has been described above with reference to various exemplary embodiments. However, those skilled in the art should understand that various modifications and alterations can be made to the present invention without departing from the spirit and scope of the invention as set forth in the claims.

Claims

1. A flatness measuring apparatus of an object to be measured, comprising: a laser light source configured above the object to be measured and generating laser light having a wavelength that can be reflected from the object to be measured; an etalon interferometer configured between the object to be measured and the laser light source and converting the laser light into an array of laser light that is irradiated to the object to be measured; a beam splitter configured between the etalon interferometer and the object to be measured; and an analysis section configured above the object to be measured and measuring flatness of the object to be measured using the array of laser light reflected from the object to be measured, wherein the array of laser light is perpendicularly incident to an upper surface of the object to be measured, the laser light source is configured in a second vertical direction and generates the laser light along the second vertical direction, wherein a first vertical direction is perpendicular to the object to be measured and the second vertical direction is parallel to the first vertical direction at other positions on a plane, and the beam splitter guides the array of laser light from the second vertical direction to the first vertical direction.

2. The flatness measuring apparatus of an object to be measured according to claim 1, wherein the analysis section is located in the first vertical direction.

3. The flatness measuring apparatus of an object to be measured according to claim 1, further comprising: a filter configured between the laser light source and the etalon interferometer and filtering the laser light.

4. The flatness measuring apparatus of an object to be measured according to claim 1, wherein the analysis section measures reflectivity corresponding to each position of the object to be measured using the array of laser light reflected from the object to be measured, and obtains thickness corresponding to each position of the object to be measured from the reflectivity.

5. The flatness measuring apparatus of an object to be measured according to claim 4, wherein the analysis section measures stress corresponding to each position of the object to be measured due to deformation of the object to be measured using the array of laser light reflected from the object to be measured.

6. The flatness measuring apparatus of an object to be measured according to claim 5, wherein the analysis section compares the stress corresponding to each position of the object to be measured and stress corresponding to each position of a reference object to be measured, thereby obtaining actual stress corresponding to each position of the object to be measured.

7. The flatness measuring apparatus of an object to be measured according to claim 1, wherein the analysis section includes an optical sensor that receives the array of laser light reflected from the object to be measured. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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