Residual film inspection system

Abstract

The residual film inspection system includes an inspection object, a stage, a light source, and a controller. The inspection object includes: a substrate in which a first region in which a transparent film is disposed, a third region in which the transparent film is not disposed, and a second region between the first region and the third region are defined; a first conductive layer disposed on the substrate; and a transparent film disposed on the first conductive layer to overlap a portion of the first conductive layer. An object to be inspected is placed on the table. The controller emits the light beam to the first position and receives the reflected light from the first position to obtain the first reflectivity of the first position, emits the light beam to the second position and receives the reflected light from the second position to obtain the second reflectivity of the second position, and calculates the difference between the first reflectivity and the second reflectivity. Thus, the presence or absence of the transparent film at the first position is determined.

Description

Technical Field

[0001] The present application relates to a residual film inspection system. More specifically, the present application relates to a residual film inspection system including a light-transmitting material and a system for performing residual film inspection. Background Art

[0002] With the development of information technology, the importance of display devices as a connection medium between users and information is increasing. Therefore, the use of display devices such as liquid crystal display devices (LCDs), organic light emitting display devices (OLEDs), and plasma display devices (PDPs) is increasing.

[0003] An ellipsometer (i.e., an ellipsometer) can determine the inherent optical information of the object under inspection (e.g., refractive index (n), extinction coefficient (k), etc.) by observing the changes in the elliptical state of light of a specific polarization state incident on and reflected from the object under inspection.

[0004] Ellipsometers can perform inspections in a general environment (e.g., without the need for high vacuum, plasma, or acid / base reaction environments) and inspect the inspection object in a non-destructive manner. Ellipsometers can inspect display panels that include multiple layers that can cause transmission and reflection at their boundaries. Ellipsometers can be used to measure the thickness of display panels using light transmitted and reflected at the boundaries of the multiple layers. Summary of the Invention

[0005] An object of the present application is to provide a residual film inspection system for improving the quality of display panels.

[0006] Another object of the present application is to provide a residual film inspection method using the residual film inspection system.

[0007] However, the purpose of the present application is not limited to the above purpose, and various extensions can be made without departing from the scope of the idea and field of the present application.

[0008] To achieve the above-mentioned objectives of the present application, a residual film inspection system according to one embodiment of the present application may include an inspection object, a stage, a light source, and a controller. The inspection object may include: a substrate defining a first region where a transparent film is arranged, a third region where no transparent film is arranged, and a second region between the first and third regions; and a first conductive layer arranged on the substrate. The transparent film may be arranged on the first conductive layer so as to overlap a portion of the first conductive layer. The inspection object may be mounted on the stage. The light source may emit a light beam. The controller may be configured to: change the path of the light beam so that the light beam is incident on a first position in the second region that is spaced a first distance from a boundary line between the first and second regions of the inspection object; change the path of the light beam so that the light beam is incident on a second position in the third region that is spaced a second distance greater than the first distance from a boundary line between the first and second regions of the inspection object; receive reflected light from the first position to obtain a first reflectivity of the first position; receive reflected light from the second position to obtain a second reflectivity of the second position; calculate the difference between the first reflectivity and the second reflectivity; and determine the presence or absence of a transparent film at the first position. By increasing the yield of display panels, the defect rate can be reduced and the process cost can be reduced.

[0009] In one embodiment, the controller can be configured to: when the difference between the first reflectivity and the second reflectivity exceeds a predetermined range, it is determined that a transparent film exists at the first position; when the difference between the first reflectivity and the second reflectivity satisfies a predetermined range, it is determined that no transparent film exists at the first position.

[0010] In one embodiment, the inspection object may be a display panel. The substrate included in the display panel may define a display area in which a light-emitting element is arranged, and a peripheral area adjacent to the display area, including a first area, a second area, and a third area. The first conductive layer and the second conductive layer may be sequentially arranged on the substrate in the second area. The controller may be further configured to determine that the display panel is defective when it is determined that a transparent film is present between the first conductive layer and the second conductive layer.

[0011] In one embodiment, the display panel may further include an additional transparent film below the transparent film in the second region. At each of the first position and the second position, the display panel may have a structure in which the additional transparent film, the first conductive layer, and the second conductive layer are sequentially arranged on the substrate.

[0012] In one embodiment, the controller may be further configured to control the display panel determined to be defective to perform a reworking process. The reworking process may be a process of removing a transparent film between the first conductive layer and the second conductive layer at a first position.

[0013] In one embodiment, the controller may be further configured to confirm whether the result of determining that the transparent film exists is a true value.

[0014] In one embodiment, when viewed in a plane, the first conductive layer may include a first wiring and a second wiring with a first gap therebetween. The spot size of the light beam may be smaller than the first gap.

[0015] In one embodiment, the residual film inspection system may further include a bandpass filter disposed on a travel path of the light emitted from the light source. The bandpass filter may allow only light of a specific wavelength of the light beam to pass therethrough.

[0016] In one embodiment, the light source may emit white light having a wavelength of about 400 nm or more and about 800 nm or less.

[0017] In one embodiment, the controller may obtain the first reflectivity and the second reflectivity as a ratio of a first intensity of light incident on the inspection object to a second intensity of light reflected from the inspection object.

[0018] In order to achieve another object of the present application, a residual film inspection method according to an embodiment of the present application may include the following steps. The residual film inspection method includes: arranging an inspection object on a table, the inspection object including a substrate, a first conductive layer and a transparent film, the substrate defining a first area where the transparent film is arranged, a third area where the transparent film is not arranged, and a second area between the first area and the third area, the first conductive layer being arranged on the substrate, and the transparent film being arranged on the first conductive layer to overlap with a portion of the first conductive layer; emitting a light beam; causing the light beam to be incident on a first position of the second area that is spaced a first distance from a boundary line between the first area and the second area of ​​the inspection object; receiving reflected light from the first position to obtain a first reflectivity of the first position; causing the light beam to be incident on a second position of the third area that is spaced a second distance greater than the first distance from the boundary line between the first area and the second area of ​​the inspection object; receiving reflected light from the second position to obtain a second reflectivity of the second position; calculating a difference between the first reflectivity and the second reflectivity; and being able to determine the presence or absence of the transparent film at the first position.

[0019] In one embodiment, a residual film inspection method can determine the presence or absence of a transparent film at a first location. When the difference between a first reflectivity and a second reflectivity exceeds a predetermined range, the presence of a transparent film can be determined. When the difference between the first reflectivity and the second reflectivity falls within the predetermined range, the absence of a transparent film can be determined.

[0020] In one embodiment, the inspection object may be a display panel. The substrate included in the display panel may define a display area in which a light-emitting element is arranged, and a peripheral area adjacent to the display area, including a first area, a second area, and a third area. The first conductive layer and the second conductive layer may be sequentially arranged on the substrate in the second area. When a transparent film is determined to be present between the first conductive layer and the second conductive layer, the residual film inspection method may determine that the display panel is defective.

[0021] In one embodiment, the display panel may further include an additional transparent film below the transparent film in the second region. At each of the first position and the second position, the display panel may have a structure in which the additional transparent film, the first conductive layer, and the second conductive layer are sequentially arranged on the substrate.

[0022] In one embodiment, the residual film inspection method may control a display panel determined to be defective to perform a reworking process. The reworking process may be a process of removing a transparent film between a first conductive layer and a second conductive layer at a first position.

[0023] In one embodiment, before controlling to perform the reworking process, the residual film inspection method may confirm whether a result determined as the presence of the transparent film is a true value.

[0024] In one embodiment, when viewed in a plane, the first conductive layer may include a first wiring and a second wiring with a first gap therebetween. The spot size of the light beam may be smaller than the first gap.

[0025] In one embodiment, the spot size of the light beam may be adjusted by passing the light beam through a bandpass filter and only allowing light having a single wavelength to pass through.

[0026] In one embodiment, the light beam emitted toward the inspection object may have a wavelength of approximately 400 nm or more and approximately 800 nm or less.

[0027] In one embodiment, each of the first reflectivity and the second reflectivity may be obtained as a ratio of a first intensity of light incident on the inspection object to a second intensity of light reflected from the inspection object.

[0028] According to an embodiment of the present application, a residual film inspection system and a residual film inspection method using the same may include an inspection object, a stage, a light source and a controller. The inspection object may include: a substrate, defining a first area where a transparent film is arranged, a third area where no transparent film is arranged, and a second area between the first area and the third area; a first conductive layer arranged on the substrate; and a transparent film arranged on the first conductive layer to overlap with a portion of the first conductive layer. The inspection object may be mounted on the stage. The controller may direct a light beam to a first position of the second area that is spaced a first distance from a boundary line between the first area and the second area of ​​the inspection object, and receive reflected light from the first position to obtain a first reflectivity of the first position, and direct a light beam to a second position of the third area that is spaced a second distance greater than the first distance from the boundary line between the first area and the second area of ​​the inspection object, and receive reflected light from the second position to obtain a second reflectivity of the second position, and calculate the difference between the first reflectivity and the second reflectivity, thereby determining the presence or absence of a transparent film at the first position.

[0029] Furthermore, when a transparent film is detected, the residual film inspection system and method can provide feedback to perform a reprocessing process (i.e., an additional process to remove the transparent film). This can reduce lead time (the time required to detect a defect in the inspection object) and increase the yield rate of the inspection object.

[0030] Furthermore, the residual film inspection system and method can verify whether the result of the determination of the presence of a transparent film is true. Therefore, it is possible to distinguish whether the determination result is a result of the actual presence of a transparent film or a result due to an equipment error.

[0031] In addition, the residual film inspection system and the residual film inspection method can pass the light beam through the bandpass filter. Therefore, the light beam can be incident on the inspection object to have a spot size smaller than the wiring composed of metal materials.

[0032] However, the effects of the present application are not limited to the above-described effects, and various extensions can be made without departing from the idea and scope of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a block diagram for explaining a residual film inspection system according to one embodiment of the present application.

[0034] Figure 2 Is used to explain the Figure 1 FIG. 1 is a diagram of an inspection object included in one embodiment of a residual film inspection system.

[0035] Figure 3 Is used to illustrate Figure 2 Figure 1 shows the A region of the .

[0036] Figure 4 It is used to indicate that Figure 2 Figure 4 shows a diagram of the pad area in the display panel.

[0037] Figure 5 It is along Figure 4 A cross-sectional view taken along line II'.

[0038] Figure 6 and Figure 7 For illustration Figure 1 A diagram of the filter unit included in the residual film inspection system.

[0039] Figures 8 to 12 Is used to illustrate Figure 1 A diagram showing the discrimination results of the residual film inspection system.

[0040] Figure 13 is used to illustrate the Figure 11 A graph of defective units in the first mapping.

[0041] Figures 14 and 15 Is used to illustrate Figure 1 A diagram showing the identification results of a defective display panel by the residual film inspection system.

[0042] Figure 16 For illustrative purposes Figure 1 Flowchart of the residual film inspection method of the residual film inspection system.

[0043] Description of Reference Numerals

[0044] A1: First area A2: Second area

[0045] A3: third area SUB: substrate

[0046] VIA1: Transparent film ILD: Extra transparent film

[0047] SD1: first conductive layer SD2: second conductive layer

[0048] LI1: First wiring LI2: Second wiring

[0049] ST: Stage 10: Light Source

[0050] BF: Bandpass filter

[0051] LB: Beam D1: First distance

[0052] D2: Second distance P1: First position

[0053] P2: Second position G1: Interval between multiple wirings

[0054] SS: spot size of the beam

[0055] CON: Difference between the first reflectivity and the second reflectivity

[0056] SI: Good quality range DETAILED DESCRIPTION

[0057] Hereinafter, embodiments of the present application will be described in more detail with reference to the accompanying drawings. The same components in the accompanying drawings are denoted by the same reference numerals, and repeated description of the same components will be omitted.

[0058] Figure 1 This is a block diagram for explaining a residual film inspection system according to one embodiment of the present application.

[0059] Reference Figure 1 The residual film inspection system 1 according to one embodiment of the present application may include an inspection object OB, a stage ST, a light source 10 , a filter unit 20 , a spectrometer 30 , a lens unit 40 , a CCD 60 , an inspection module 50 , and a controller 70 .

[0060] In one embodiment, the inspection object OB may be mounted on the stage ST. For example, the inspection object OB may include a plurality of display panels (eg, Figure 2 The mother substrate of the display panel 100 is a mother substrate. For example, the mother substrate can be a substrate for a display device such as an organic light-emitting display panel, a liquid crystal display panel, or a plasma display panel. For example, the mother substrate can include a plurality of units. The plurality of units can be separated to form a plurality of display panels. The detailed description of the display panel will be referred to later. Figure 2 The following figures are described.

[0061] For example, the ellipsometer may include a light source 10, a spectrometer 30, a lens unit 40, and a CCD 60 in addition to the filter unit 20. The ellipsometer can perform inspection in a general environment (e.g., without requiring a high vacuum, a plasma environment, an acid / base reaction environment, etc.), and can inspect the inspection object OB in a non-destructive manner. For example, a display panel or the like after the residual film inspection is completed cannot be used due to damage to the inspection object OB by a destructive analyzer (e.g., a TEM), which may reduce production yield.

[0062] In one embodiment, the light source 10 may emit a light beam LB. In one embodiment, the light source 10 may emit white light having a wavelength in the visible light range. For example, the wavelength may be approximately 400 nm or more and 800 nm or less. For example, the light source 10 may include a halogen lamp. However, the present application is not limited thereto. For example, the light source 10 may include a variety of light beam emitting devices.

[0063] In one embodiment, the filter unit 20 may be arranged on a path of travel of the light beam LB emitted from the light source 10. In one embodiment, the filter unit 20 may include a bandpass filter (e.g., Figure 6 The bandpass filter BF) and the main body RO of the rotating bandpass filter (such as Figure 6 In one embodiment, the bandpass filter may allow only light of a specific wavelength to pass through the light beam LB emitted from the light source 10. For example, the blue bandpass filter may allow only light of a wavelength of approximately 450 nm to pass through.

[0064] When the thickness of a film included in the display panel is measured using an ellipsometer, white light can be measured from an opening defined in the filter unit 20 (eg, Figure 6 The hole HO) passes through.

[0065] In addition, when a residual film included in the display panel is inspected using an ellipsometer, white light may pass through the band pass filter included in the filter unit 20 .

[0066] In other words, by adding the filter unit 20 to the ellipsometer, the thickness of the film included in the display panel can be measured without additional equipment, and the presence / absence of a residual film included in the display panel can also be checked.

[0067] For example, the beam splitter 30 may be disposed on the path of the light beam LB. The beam splitter 30 may cause a portion of the light beam LB to be incident on the inspection object OB, while allowing the remaining portion to pass through the beam splitter 30. For example, the beam splitter 30 may be a half-reflecting mirror. 50% of the light beam LB incident on the half-reflecting mirror may be incident on the inspection object OB. However, the present application is not limited thereto.

[0068] For example, the lens unit 40 may include an objective lens, and the objective lens may adjust magnification.

[0069] For example, the inspection module 50 may include an optical inspector. The optical inspector may inspect the presence / absence and thickness of a residual film included in the inspection object OB. For example, the optical inspector may include a camera.

[0070] For example, the camera can be a line scan camera. The optical inspector can observe an area of ​​n×m (wherein each of n and m is greater than 0 mm). For example, the line scan camera can observe an area of ​​about 50 mm×about 50 mm. The line scan camera can observe the inspection object OB while moving. For example, in cases where precision inspection is required, the mother substrate can be pre-inspected. For another example, the thickness of the inspection object OB is first inspected, and the presence / absence of a residual film is only inspected for the portion whose thickness exceeds a predetermined range. In other words, the inspection method can be variously changed, taking into account the degree of good product determination of the inspection object OB (there are display panels that are determined to be good only if there is no residual film at all, and there are display panels that are determined to be good even if there is a residual film of a predetermined thickness), the inspection time, etc.

[0071] For example, the CCD 60 can measure the intensity of reflected light of each wavelength. For example, the light beam LB may be incident on the inspection object OB and then reflected from the inspection object OB. The reflected light may be received by the CCD 60.

[0072] For example, the light beam LB may be outputted at 100% from the light source 10. When the reflected light reflected from the inspection object OB is received by the CCD 60 at approximately 30% of the light quantity, the reflectance may be calculated as approximately 30%.

[0073] For example, the light beam LB emitted from the light source 10 is incident on the inspection object OB as linearly polarized light, and the first reflected light reflected from the inspection object OB and the second reflected light reflected from the surface of the substrate after passing through the inspection object OB can be received by the CCD60. For example, as the second reflected light passes through the inspection object OB, the wavelength, phase, amplitude, etc. may be different from those of the first reflected light. The first reflected light and the second reflected light may be circularly polarized and linearly polarized again. Thereafter, the presence / absence of a residual film can be detected by the phase difference and amplitude difference (i.e., polarization difference) of the polarized reflected light. However, the present application is not limited thereto.

[0074] In one embodiment, the controller 70 can perform various functions. For example, the controller 70 can be a computer. However, the present application is not limited thereto.

[0075] For example, the controller 70 may change (correct) the path of the light beam LB so that the light beam LB is incident on a predetermined position (eg, Figure 3 When the path of the light beam LB is set by the controller 70, the path of the light beam LB may be modified by the path changing component.

[0076] For example, the controller 70 may receive an inspection image from the inspection module 50. The controller 70 may receive an inspection image from the inspection module 50. Figure 3)Set the inspection location (for example, Figure 3 A first position P1 of the inspection position may be set, and a reference position for comparison with the inspection position may be set (eg, Figure 3 For example, the first position can be a position for checking the presence or absence of a residual film, and the second position can be a reference position for comparison with the first position. For example, the image can be grayscaled. For example, the grayscale can be a value that combines amplitude and phase according to the wavelength of light. For example, the grayscale can be set to about 1 to about 255. In this case, 1 can represent black, and 255 can represent white.

[0077] For example, the controller 70 may receive light intensity from the CCD 60. In one embodiment, the controller 70 may obtain a first reflectivity at a first position and a second reflectivity at a second position, calculate the difference between the first reflectivity and the second reflectivity, and thereby determine whether there is a residual film at the first position.

[0078] When the reflectivity is measured only at a single location, the reflectivity may be measured to be larger or smaller depending on the thickness of the film. That is, since the reflectivity changes not only depending on the presence or absence of residual film but also depending on the thickness of the film, it is difficult to detect the presence or absence of residual film using only the reflectivity at a single location.

[0079] In one embodiment, the first reflectivity may be obtained as a ratio of a first intensity to a second intensity. The first intensity may represent the intensity of light incident on the inspection object OB, and the second intensity may represent the intensity of light reflected from the inspection object OB.

[0080] Similarly, the second reflectivity can be obtained as a ratio of the third intensity to the fourth intensity. The third intensity can represent the intensity of light incident on the inspection object OB. The fourth intensity can represent the intensity of light reflected from the inspection object OB.

[0081] The residual film inspection system 1 according to the present application determines the presence or absence of a residual film by the difference between the first reflectivity and the second reflectivity, thereby eliminating the need for a separate inspection mark to determine the presence or absence of a residual film.

[0082] For example, the intensity of light received at locations having the same underlying film structure (i.e., the first and second locations) can be measured. For example, the number of transparent films, thickness, etc., that the light beam LB passes through at each of the first and second locations can be substantially the same. Therefore, reflectivity errors caused by differences in underlying film structure can be eliminated.

[0083] In the case of the residual film inspection system according to the comparative example, a metal bond is formed on the substrate, and a third reflectivity of the portion where the metal bond is arranged is obtained. This is compared with the reflectivity before the metal bond is formed, thereby determining whether a residual film is present in the portion where the metal bond is arranged. In this case, additional processes and time are required to form the metal bond, and if metal bonds are difficult to form (for example, display panels including small-sized substrates), it may be difficult to inspect the residual film.

[0084] Furthermore, when an additional transparent film exists under the residual film, the residual film inspection system according to the comparative example including only the optical meter without the filter unit 20 may have difficulty in finding the residual film.

[0085] However, in the case of the residual film inspection system 1 according to one embodiment of the present application, the presence or absence of the residual film can be determined by the difference between the first reflectivity and the second reflectivity without an additional inspection mark.

[0086] In one embodiment, when the difference between the first reflectivity and the second reflectivity satisfies a predetermined range, the controller 70 may determine that no residual film exists at the first position. In other words, when the difference between the first reflectivity and the second reflectivity exceeds a predetermined range, the controller 70 may determine that a residual film exists at the first position.

[0087] In one embodiment, when the controller 70 determines that a residual film is present, the display panel may be determined to be defective. For example, a growing dark spot may occur in the display panel. For example, when a residual film is present, current may not flow due to the residual film. Consequently, a portion of the display panel may not be driven.

[0088] The controller 70 can control the execution of the reprocessing process. The reprocessing process can represent a process for removing the residual film from the display panel. For example, when the controller 70 determines that there is a residual film, the controller 70 can generate an alarm. As another example, when the controller 70 determines that there is a residual film, the controller 70 can suspend the manufacturing process of the display panel. Therefore, the generation of defects can be prevented. In one embodiment, the controller 70 can determine whether the result of determining that there is a residual film is a true value. Therefore, when the judgment result is an error according to the residual film inspection system 1, the reprocessing process is not performed. If the judgment result is based on the presence of a residual film, the reprocessing process can be performed. By increasing the output of the display panel, the defective rate can be reduced and the process cost can be reduced.

[0089] However, the present application is not limited thereto. For example, the structure of the residual film inspection system 1 may be modified in various ways. For example, in the residual film inspection system 1, the spectrometer 30 may be omitted. As another example, the residual film inspection system 1 may further include other components such as a mobile device.

[0090] Figure 2 Is used to explain the Figure 1 FIG. 1 is a diagram of an inspection object included in an embodiment of a residual film inspection system.

[0091] For example, Figure 2 is a plan view of a display device including the display panel 100 .

[0092] Reference Figure 2 , for example, the inspection object OB may include a display panel 100 , a printed circuit film 300 , and a main circuit board 500 .

[0093] In one embodiment, the display panel 100 may include a substrate (eg, a substrate defining a display area DA and a peripheral area NA) . Figure 3 In one embodiment, the light-emitting element PX may be arranged in the display area DA on the substrate SUB. In one embodiment, the peripheral area NA may be adjacent to the display area DA. For example, circuit structures and the like may be arranged in the peripheral area NA on the substrate SUB. The peripheral area NA may include a pad area PA.

[0094] The pad area PA may include a plurality of pads. Figure 3 The pads are described in detail. For example, the printed circuit film 300 may be in contact with the pads. The main circuit board 500 may be connected to the printed circuit film 300.

[0095] However, this is merely an example, and the components included in the inspection object OB can be variously modified.

[0096] Figure 3 Is used to illustrate Figure 2 A diagram of area A;

[0097] For example, Figure 3 is a diagram showing a simplified inspection image (e.g., using Figure 1 Inspection module 50 shooting Figure 2 Figure 1 shows an image of area A.

[0098] Reference Figure 2 and Figure 3 In one embodiment, the inspection object OB may include a display panel 100. The display panel 100 may include a substrate SUB. However, the present application is not limited thereto. For example, the inspection object OB may be various products requiring residual film inspection.

[0099] In one embodiment, the substrate SUB may define a first area A1, a second area A2, and a third area A3 on a plane. The plane may be defined according to a first direction DR1 and a second direction DR2. For example, the second direction DR2 may intersect the first direction DR1. For example, the second direction DR2 may be perpendicular to the first direction DR1.

[0100] In one embodiment, Figure 2 The pad area PA in the included peripheral area NA may include a first area A1, a second area A2, and a third area A3. On a plane, the second area A2 may be located between the first area A1 and the third area A3. The second area A2 may represent an area (i.e., an inspection target area) that requires inspection for the presence / absence of a residual film.

[0101] In one embodiment, a residual film (eg, a transparent film including a light-transmitting material (eg, Figure 5 The transparent film may not be disposed in the third area A3, but may be disposed in the second area A2. In other words, the second area A2 is adjacent to the first area A1, and the transparent film may or may not be disposed in the second area A2.

[0102] For example, Figure 1 The residual film inspection system 1 can store the first area A1 and the third area A3. In other words, the residual film inspection system 1 can pre-store information about the area where the transparent film is to be arranged (for example, the first area A1) and the area where the transparent film is not arranged (for example, the third area A3), and can set the inspection target area (for example, the second area A2).

[0103] However, the present application is not limited thereto. When the inspection object OB changes, the size, position, etc. of the inspection target area can be changed in various ways. In addition, the setting method of the inspection target area can be changed in various ways.

[0104] In one embodiment, the first reflectivity may be a reflectivity at a first position P1 of the second area A2 , and the second reflectivity may be a reflectivity at a second position P2 of the third area A3 .

[0105] In one embodiment, the first position P1 may be a position spaced a first distance D1 from the boundary between the first area A1 and the second area A2. As described above, the first position P1 may indicate the position of the inspection object. In other words, it may indicate a position adjacent to the area where the transparent film is disposed (i.e., the first area A1) and where the transparent film may not have been removed and may be present.

[0106] In one embodiment, the second position P2 may be a position spaced a second distance D2 from the boundary between the first area A1 and the second area A2. The second distance D2 may be greater than the first distance D1. As described above, information about the third area A3 may be pre-stored. By comparing the second reflectivity at the second position P2 with the first reflectivity, it is possible to inspect the presence or absence of a residual film without requiring an additional inspection mark.

[0107] The pad PD may include a plurality of wirings LI1, LI2, LI3, and LI4 on a plane. For example, each of the plurality of wirings LI1, LI2, LI3, and LI4 may include a metal material. When a light beam (e.g., Figure 1 When the light beam (LB) in the image is reflected by a metal material, its reflectivity can increase. This can affect the determination of the presence or absence of a residual film. For example, even if a residual film is present in the second area A2, the high reflectivity of the metal material may lead to an erroneous determination that the residual film is absent.

[0108] According to an embodiment of the present application, a residual film inspection system (eg, Figure 1 The residual film inspection system 1) can adjust the spot size SS of the light beam LB so that the spot size SS of the light beam LB is smaller than the interval G1 between the multiple wirings LI1, LI2, LI3 and LI4. For example, when white light is used, the spot size SS of the light beam LB can be about 50 micrometers (μm), and the spot size SS of the light beam LB passing through the bandpass filter can be about 1 micrometer (μm). As the spot size SS of the light beam LB decreases, the wavelength interval of the light beam LB used for measurement can be increased from about 0.1nm to about 10nm. As the number of measurement result values ​​decreases, the resolution may decrease accordingly. However, since the residual film inspection system can only determine the presence / absence of a residual film, the resolution can be ignored.

[0109] Furthermore, as described below, when the residual film inspection system is used to measure thickness, it is possible to measure the thickness by passing white light through an opening (e.g., Figure 6 Thickness measurements can be performed using a hole (HO) without sacrificing resolution.

[0110] By adjusting the spot size SS of the light beam LB, it is possible to avoid measuring the reflectivity caused by the residual film, thereby preventing misjudgment caused by the metal material.

[0111] In one embodiment, the filter may be passed through a bandpass filter (e.g., Figure 1 The spot size SS is adjusted by using a bandpass filter in the filter unit 20. Figure 6 The following content is described.

[0112] Figure 4 Is used to illustrate Figure 2 FIG. 1 is a diagram of pad areas defined in a display panel. Figure 5 It is along Figure 4 A cross-sectional view taken along line II'.

[0113] Reference Figure 2 、 Figure 4 and Figure 5 , the pads PD may be arranged in the pad area PA.

[0114] The pad PD may include a plurality of conductive layers. In one embodiment, the pad PD may include a first conductive layer SD1, a second conductive layer SD2, and a third conductive layer SD3 sequentially stacked on the substrate SUB.

[0115] Multiple insulating films VIA may be arranged between the multiple conductive layers. For example, a first insulating film VIA1 may be arranged on the substrate SUB and the first conductive layer SD1, a second conductive layer SD2 may be arranged on the first insulating film VIA1, a second insulating film VIA2 may be arranged on the second conductive layer SD2 and the first insulating film VIA1, a third conductive layer SD3 may be arranged on the second insulating film VIA2, and a third insulating film VIA3 may be arranged on the third conductive layer SD3 and the second insulating film VIA2. In other words, in one embodiment, the first insulating film VIA1 may overlap with a portion of the first conductive layer SD1, the second insulating film VIA2 may overlap with a portion of the second conductive layer SD2, and the third insulating film VIA3 may overlap with a portion of the third conductive layer SD3.

[0116] In one embodiment, each of the plurality of insulating films VIA may include a light-transmitting material, that is, each of the plurality of insulating films VIA may be a transparent film.

[0117] For example, each of the plurality of insulating films VIA may include a photoresist. The photoresist may be developed by patterning. At this time, a portion of the photoresist may not be removed and may remain. Therefore, in one embodiment, a transparent film (e.g., the first insulating film VIA1) may be disposed in the first area A1 but not in the third area A3. A transparent film may or may not be disposed in the second area A2.

[0118] Although Figure 5 For example, when the transparent film (ie, the residual film) represents another insulating film, the position, size, etc. of the first area A1, the second area A2, and / or the third area A3 may be variously changed.

[0119] In one embodiment, an additional transparent film (eg, a planarization layer ILD) may be disposed between the substrate SUB and the transparent film (eg, any one of the plurality of insulating films VIA). Figure 2 The display panel 100 may have a structure in which an additional transparent film (eg, a planarization layer ILD), a first conductive layer SD1, a transparent film (eg, a first insulating film VIA1), and a second conductive layer SD2 are sequentially arranged on a substrate SUB.

[0120] In the case of the residual film inspection system according to the comparative example, when an additional transparent film is present, the presence of a residual film may not be determined, or the accuracy of determining the presence of a residual film may be reduced due to the influence of the reflectivity of the additional transparent film. For example, the presence of a residual film may not be determined, or the accuracy of determining the presence of a residual film may be reduced due to the additional reflected light caused by the additional transparent film.

[0121] However, in a residual film inspection system according to one embodiment of the present application (eg, Figure 1 In the case of the residual film inspection system 1), even if there is an additional transparent film, the presence or absence of the residual film can be detected more accurately. To this end, the residual film inspection system can determine the presence or absence of the residual film by a numerical value (i.e., the difference between the first reflectivity and the second reflectivity). For detailed information on this, please refer to Figure 8 The following content is described.

[0122] Figure 6 and Figure 7 Is used to illustrate Figure 1 A diagram of the filter unit included in the residual film inspection system.

[0123] Reference Figure 1 and Figure 6 , the filter unit 20 may include a body RO and a bandpass filter BF.

[0124] The bandpass filter BF may include multiple filters F1, F2, F3, ..., FN. When white light passes through any one of the multiple filters F1, F2, F3, ..., FN, only light of a specific wavelength may pass through. For example, each of the multiple filters F1, F2, F3, ..., FN may change the wavelength of light that can pass through by approximately 10 nm. However, the present application is not limited to this.

[0125] For example, the reflectivity (eg, the first reflectivity and the second reflectivity) may be measured for all wavelengths of visible light. Therefore, the reflectivity for each wavelength may be measured.

[0126] For example, the wavelength that maximizes the difference in reflectivity can vary depending on the type of material included in the residual film. Furthermore, the wavelength that maximizes the difference in reflectivity can vary depending on the type of material included in the additional transparent film beneath the residual film. Therefore, reflectivity can be measured over the entire visible light wavelength range.

[0127] Furthermore, the measurement of the reflectivity may be performed for all wavelengths of visible light to confirm whether the difference between the reflectivities is due to an error of the device (ie, to determine whether the difference between the reflectivities is a true value).

[0128] To this end, the center of the main body RO may be connected to a rotation axis, and the main body RO may rotate around the rotation axis. Figure 8 The following content is described.

[0129] like Figure 7 As shown, the first light L1 passing through the lens unit 40 may be focused on a first position F1 , and the second light L2 may be focused on a second position F2 .

[0130] For example, when aligned based on the second light L2, the spot size (eg, Figure 3 The spot size SS in the beam may be increased. In this case, as described above, the beam (e.g. Figure 1 The light beam LB) may be incident on a wiring including a metal material (e.g., Figure 3 On the plurality of wirings LI1, LI2, LI3 and LI4) included in the pad PD.

[0131] However, the residual film inspection system 1 according to an embodiment of the present application can reduce the spot size by passing only light having a specific wavelength and aligning based on the light having the specific wavelength. In an embodiment, the spot size can be smaller than the interval between the plurality of wirings.

[0132] In summary, the residual film inspection system 1 according to one embodiment of the present application can be used for thickness measurement and / or residual film inspection (using reflectivity measurement). For example, in the case of thickness measurement, white light can pass through the hole HO defined in the main body RO of the filter unit 20. In the case of residual film inspection, white light can pass through any one of the bandpass filters BF.

[0133] Figures 8 to 12 Is used to explain the Figure 1 A diagram showing the discrimination results of the residual film inspection system.

[0134] exist Figure 8 In the figure, the X-axis represents the wavelength W and the Y-axis represents the reflectivity RI (i.e., Figure 3a first reflectivity at a first position P1 and a second reflectivity at a second position P2).

[0135] exist Figure 9 , the X-axis represents the wavelength W, and the Y-axis represents the value CON (ie, the result of calculating the difference between the first reflectivity and the second reflectivity).

[0136] Reference Figure 1 、 Figure 3 、 Figure 8 and Figure 9 In one embodiment, the controller 70 may obtain a first reflectivity at the first position P1 and a second reflectivity at the second position P2, and obtain a value CON (ie, a result of calculating the difference between the first reflectivity and the second reflectivity).

[0137] Figure 10 The X-axis represents the wavelength W, and the Y-axis represents the value CON (ie, the result of calculating the difference between the first reflectivity and the second reflectivity).

[0138] Reference Figure 1 、 Figure 3 and Figure 10 In one embodiment, the presence or absence of a transparent film (ie, a residual film) can be determined by the numerical value CON (ie, the result of calculating the difference between the first reflectivity and the second reflectivity).

[0139] In one embodiment, when the value CON (i.e., the result of calculating the difference between the first reflectivity and the second reflectivity) exceeds a predetermined range, the controller 70 can determine that the transparent film exists at the first position P1, and when the value CON (i.e., the result of calculating the difference between the first reflectivity and the second reflectivity) satisfies the predetermined range, the controller 70 can determine that the transparent film does not exist at the first position P1. In other words, when the value CON (i.e., the result of calculating the difference between the first reflectivity and the second reflectivity) satisfies the defective range SO that exceeds the good range SI, the display panel (e.g., Figure 2 The display panel 100 is judged as a defective product because a transparent film (i.e., a residual film) exists in the second area A2. When the value CON (i.e., the result of calculating the difference between the first reflectivity and the second reflectivity) satisfies the good product range SI, the display panel is judged as a good product because no transparent film exists in the second area A2. To this end, the good product range SI can be stored in the controller 70.

[0140] The good range SI can be changed in various ways depending on the product (for example, the type of display panel). For example, the good range SI can be set to about 10. In other words, the good range SI can be set to about -10 to +10. For example, when the numerical value CON (that is, the result of calculating the difference between the first reflectivity and the second reflectivity) is about +2, the display panel can be determined to be a good product. On the other hand, when the numerical value CON (that is, the result of calculating the difference between the first reflectivity and the second reflectivity) is about +13, the display panel can be determined to be a defective product. For example, there are products that will not produce defects such as dark spots only if all residual films are eliminated, or there are products that will not produce defects such as dark spots even if the residual film has a predetermined thickness.

[0141] Figure 11 The first map MA1 is a map that integrates the actual locations where the failure occurs. Figure 12 is a diagram of a second map MA2 integrating the results of the measurements.

[0142] Reference Figure 10 、 Figure 11 and Figure 12 , according to a residual film inspection system of one embodiment of the present application (for example, Figure 1 The residual film inspection system 1) can perform residual film inspection in the mother glass state. For example, the mother glass can refer to a substrate before the mother glass is divided into units.

[0143] For example, Figure 11 As shown, residual film can be induced by adjusting the exposure energy. For example, when the exposure energy is small, the transparent film cannot be completely eliminated and residual film may be induced. Figure 11 It is a map of the extent of the residual film and the location of the residual film after the residual film is induced.

[0144] Figure 12 is by using a residual film inspection system according to an embodiment (e.g., Figure 1 The residual film inspection system 1) performs mapping of the results of the residual film inspection.

[0145] like Figure 10 As described in , the good quality range SI can be varied depending on the product (eg, the type of display panel). When the good quality range SI is set to approximately 10, a portion less than -10 or greater than +10 may be determined as defective.

[0146] For example, Figure 12 FQ of good units Figure 10 The value CON (ie, the result of calculating the difference between the first reflectivity and the second reflectivity) is approximately +2, satisfying the good product range SI, and the value of the defective unit DQ is approximately 20, exceeding the good product range SI.

[0147] Observe carefully Figure 11 and Figure 12 , unlike the good product unit FQ, the defective product unit DQ can verify the part of the residual film induced by insufficient exposure energy. In other words, it can verify the Figure 1 The residual film inspection system 1 matches the portion predicted as a defective unit DQ with the portion that actually induces the residual film.

[0148] Figure 13 Is used to illustrate Figure 11 Figure 1 shows a graph of defective units. Figures 14 and 15 Is used to illustrate Figure 13 A diagram showing the results of identifying defective units.

[0149] Reference Figure 13 , when viewed from a cross section (eg, a plane defined by the second direction DR2 and the third direction DR3), Figure 5 Unlike the display panels of the good quality cells FQ, the display panels of the defective quality cells DQ can confirm that the first insulating film VIA1 is arranged in the second area A2'. For example, the third direction DR3 can intersect each of the first direction DR1 and the second direction DR2. For example, the third direction DR3 can be perpendicular to each of the first direction DR1 and the second direction DR2.

[0150] In this case, the first conductive layer SD1 and the second conductive layer SD2 cannot contact each other due to the first insulating film VIA1 , so defects such as dark spots may occur in the display panel.

[0151] Figure 14 The X-axis represents the wavelength W, and the Y-axis represents the reflectivity RI (i.e., the wavelength corresponding to Figure 3 The first reflectivity at the position P1' of the first position and the first reflectivity at the position P1' corresponding to Figure 3 a second reflectivity at position P2′ of the second position of FIG.

[0152] exist Figure 15 The X-axis represents the wavelength W, and the Y-axis represents the value CON (ie, the result of calculating the difference between the first reflectivity and the second reflectivity).

[0153] Reference Figure 14 and Figure 15 , according to a residual film inspection system of one embodiment of the present application (for example, Figure 1 The residual film inspection system 1) when the value CON (i.e., the result of calculating the difference between the first reflectivity and the second reflectivity) exceeds a predetermined range (e.g., Figure 10When the value CON (i.e., the calculated difference between the first reflectivity and the second reflectivity) exceeds the acceptable range SI, the display panel can be determined to be a defective product with a transparent film (i.e., a residual film) in the second area A2'.

[0154] In this case, the display panel determined to be defective may be controlled to undergo a reworking process. As described above, the reworking process may refer to a process of removing an insulating film between conductive layers (eg, a process of removing the first insulating film VIA1 between the first conductive layer SD1 and the second conductive layer SD2).

[0155] Figure 16 For illustrative purposes Figure 1 Flowchart of the residual film inspection method of the residual film inspection system.

[0156] In the following, the above references will be briefly described or omitted. Figures 1 to 15 The description of the above-mentioned residual film inspection system (e.g., Figure 1 Description of residual film inspection system 1) and repeated description.

[0157] Reference Figure 16 According to one embodiment of the present application, a residual film inspection method 2 may include the following steps. Residual film inspection method 2 includes: arranging an inspection object on a table (S100), wherein the inspection object includes a substrate, a first conductive layer and a transparent film, the substrate is defined on a plane with a first area where the transparent film is arranged, a third area where the transparent film is not arranged, and a second area between the first area and the third area, the first conductive layer is arranged on the substrate, and the transparent film is arranged on the first conductive layer to overlap with a portion of the first conductive layer; emitting a light beam (S200); causing the light beam to be incident on a first position of the second area that is spaced a first distance from a boundary line between the first area and the second area of ​​the inspection object (S400); receiving reflected light from the first position to obtain a first reflectivity of the first position (S500); causing the light beam to be incident on a second position of the third area that is spaced a second distance greater than the first distance from the boundary line between the first area and the second area of ​​the inspection object (S600); receiving reflected light from the second position to obtain a second reflectivity of the second position (S700); calculating a difference between the first reflectivity and the second reflectivity (S800); and determining whether there is a transparent film at the first position (S900).

[0158] In one embodiment, a residual film inspection method can determine the presence or absence of a transparent film at a first location. The presence of a transparent film can be determined when the difference between a first reflectivity and a second reflectivity exceeds a predetermined range, and the absence of a transparent film can be determined when the difference between the first reflectivity and the second reflectivity falls within the predetermined range.

[0159] In one embodiment, the inspection object may be a display panel. The substrate included in the display panel may define a display area in which a light-emitting element is arranged, and a peripheral area adjacent to the display area, including a first area, a second area, and a third area. The first conductive layer and the second conductive layer may be sequentially arranged on the substrate in the second area. When a transparent film is determined to be present between the first conductive layer and the second conductive layer, the residual film inspection method may determine that the display panel is defective.

[0160] In one embodiment, the display panel may further include an additional transparent film below the transparent film in the second region. At each of the first position and the second position, the display panel may have a structure in which the additional transparent film, the first conductive layer, and the second conductive layer are sequentially arranged on the substrate.

[0161] In one embodiment, the residual film inspection method 2 may control a display panel determined to be defective to perform a reworking process ( S1100 ). The reworking process may be a process of removing a transparent film between the first conductive layer and the second conductive layer at a first position.

[0162] In one embodiment, before controlling to perform the reworking process, the residual film inspection method 2 may confirm whether the result determined as the presence of the transparent film is a true value.

[0163] In one embodiment, when viewed in a plane, the first conductive layer may include a first wiring and a second wiring with a first gap therebetween. The spot size of the light beam may be smaller than the first gap.

[0164] In one embodiment, the spot size of the light beam may be adjusted by passing the light beam through a bandpass filter and passing only light having a single wavelength ( S300 ).

[0165] In one embodiment, the light beam emitted toward the inspection object may have a wavelength of approximately 400 nm or more and approximately 800 nm or less ( S200 ).

[0166] In one embodiment, each of the first reflectivity and the second reflectivity may be obtained as a ratio of a first intensity of light incident on the inspection object to a second intensity of light reflected from the inspection object ( S500 , S700 ).

[0167] In addition, when it is determined that a transparent film is present, the residual film inspection method can be fed back to perform a reprocessing process (i.e., an additional process to eliminate the transparent film) (S1100). Therefore, the lead time (the time required to find a defective inspection object) can be reduced, and the yield rate of the inspection object can be increased. For example, it takes about 7 minutes to measure the thickness, while it takes about 14 minutes to inspect the residual film. That is, by adding about a few minutes, the presence / absence of the residual film can be determined in advance, the generation of defects can be prevented, and the lead time can be reduced. As described above, the number of units performing the residual film inspection, the residual film inspection time, etc. can be variously changed.

[0168] The residual film inspection method can confirm whether the result of the determination of the presence of the transparent film is a true value (S1000). Therefore, it can be determined whether the determination result is a result of the actual presence of the transparent film or a result due to an error in the equipment.

[0169] The residual touch inspection method can pass the light beam through a bandpass filter. Therefore, the light beam can be incident on the inspection object to have a spot size smaller than that of the wiring including the metal material (S300). Therefore, the influence of the reflectivity caused by the metal material can be eliminated.

[0170] Industrial availability

[0171] The residual film inspection system and the residual film inspection method using the same according to the exemplary embodiment of the present application can be applied to the process of manufacturing display devices included in computers, laptops, mobile phones, smart phones, smart tablets, portable media players (PMPs), personal digital assistants (PDAs), MP3 players, etc.

[0172] Although the above description refers to the embodiments of the present application, it will be understood by those skilled in the art that various modifications and changes can be made to the present application without departing from the scope of the idea and field of the present application as described in the claims.

Claims

1. A residual film inspection system comprising: Inspection objects include: a substrate defining a first region where a transparent film is arranged, a third region where the transparent film is not arranged, and a second region between the first region and the third region, and a first conductive layer disposed on the substrate, wherein the transparent film is arranged on the first conductive layer to overlap with a portion of the first conductive layer, a table on which the inspection object is mounted, Light source, emitting a beam of light, The controller configuration is: changing the path of the light beam so that the light beam is incident on a first position of the second area of ​​the inspection object that is spaced a first distance from a boundary line between the first area and the second area, changing the path of the light beam so that the light beam is incident on a second position of the third area that is spaced apart from a boundary line between the first area and the second area of ​​the inspection object by a second distance greater than the first distance, receiving reflected light from the first position to obtain a first reflectivity of the first position, receiving reflected light from the second position to obtain a second reflectivity of the second position, calculating a difference between the first reflectivity and the second reflectivity, and The presence or absence of the transparent film at the first position is determined.

2. The residual film inspection system according to claim 1, wherein: The controller is configured as follows: When the difference between the first reflectivity and the second reflectivity exceeds a predetermined range, it is determined that the transparent film exists at the first position. When the difference between the first reflectivity and the second reflectivity satisfies the predetermined range, it is determined that the transparent film does not exist at the first position.

3. The residual film inspection system according to claim 1, wherein: The inspection object is a display panel, The display panel includes a substrate defining a display area in which light-emitting elements are arranged, and a peripheral area including the first area, the second area, and the third area and adjacent to the display area. The first conductive layer and the second conductive layer are sequentially arranged on the substrate in the second region. The controller is further configured to determine that the display panel is defective when determining that the transparent film exists between the first conductive layer and the second conductive layer.

4. The residual film inspection system according to claim 3, wherein: The display panel further includes an additional transparent film below the transparent film in the second area, At each of the first position and the second position, the display panel has a structure in which the additional transparent film, the first conductive layer, and the second conductive layer are sequentially arranged on the substrate.

5. The residual film inspection system according to claim 3, wherein: The controller is further configured to control the display panel determined to be defective to perform a reworking process, The reworking process is a process of eliminating the transparent film between the first conductive layer and the second conductive layer at the first position.

6. The residual film inspection system according to claim 5, wherein: The controller is further configured to confirm whether the result of determining that the transparent film exists is a true value.

7. The residual film inspection system according to claim 1, wherein: When viewed in a planar manner, the first conductive layer includes a first wiring and a second wiring having a first gap therebetween. The spot size of the light beam is smaller than the first interval.

8. The residual film inspection system according to claim 1, further comprising: a bandpass filter arranged on a travel path of light emitted from the light source, in, The bandpass filter passes only light of a specific wavelength of the light beam.

9. The residual film inspection system according to claim 1, wherein: The light source emits white light having a wavelength of 400 nm or more and 800 nm or less.

10. The residual film inspection system according to claim 1, wherein: The controller obtains the first reflectivity and the second reflectivity as a ratio of a first intensity of light incident on the inspection object to a second intensity of light reflected from the inspection object.

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