Alignment inspection device and method for micro LED panel

Abstract

The present invention relates to an alignment inspection device and method for a micro LED panel, and aims to provide an alignment inspection device and method for a micro LED panel capable of inspecting the alignment of micro LED chips within a micro LED panel regardless of the positional precision of a stage on which the micro LED panel is mounted, the presence or absence of a reference point for determining the position of micro LED chips, and the size of the micro LED chips. The alignment inspection device for a micro LED panel according to the present invention comprises: a stage on which a micro LED panel having arranged micro LED chips is mounted and which is movable along the X-axis and Y-axis; a capturing unit that captures an image of an inspection area in which at least a preset number of said micro LED chips are arranged on the micro LED panel mounted on the stage; and a control unit that measures the relative distance between said micro LED chips within the inspection area based on the image and determines the suitability of the alignment of said micro LED chips in the inspection area based on the measured distance.

Description

Technology Field

[0001] The present invention relates to an alignment inspection device and method for a micro LED panel, and more specifically, to an alignment inspection device and method for a micro LED panel that determines the suitability of the alignment of micro LED chips by measuring the distance between micro LED chips. Background Technology

[0002] Unlike OLEDs and LCDs that utilize deposition and patterning processes, Micro LED panels are manufactured by attaching Micro LED chips, which are pixel elements, to a backplane substrate through a transfer process.

[0003] Generally, the transfer process for manufacturing micro LED panels can be divided into a primary transfer process, in which micro LED chips are transferred from a wafer to an interposer, and a secondary transfer process, in which micro LED chips are transferred from the interposer to a backplane substrate. During this process, a difference may occur between the designed position of the micro LED chips and the actual position. If the micro LED chips deviate from the designed position, defects such as shorts or open circuits may occur, and even if the deviation is not significant, variations in chromaticity may occur due to the mixing of R, G, and B colors.

[0004] Accordingly, a technology has been proposed to verify the alignment of micro LED chips by identifying their positional information based on the pattern on the backplane substrate. However, conventional technology has the problem that the positional information of the micro LED chips depends on the positional precision of the stage on which the micro LED panel is mounted, and the error increases as the size of the micro LED chips becomes smaller. In addition, once the bonding of the micro LED chips to the backplane substrate is completed, the pattern on the backplane substrate becomes invisible due to the micro LED chips, making it difficult to identify the positional information of the micro LED chips.

[0005] Therefore, there is a need to develop a technology capable of inspecting the alignment of micro-LED chips within a micro-LED panel regardless of the positional precision of the stage on which the micro-LED panel is mounted, the presence or absence of reference points within the micro-LED panel to determine the position of the micro-LED chips, and the size of the micro-LED chips. Prior art literature

[0006] Registered Patent Publication No. 10-1410037 (June 20, 2014) The problem to be solved

[0007] Accordingly, the objective of the present invention is to provide an alignment inspection device and method for a micro LED panel that can inspect the alignment of micro LED chips within a micro LED panel regardless of the positional precision of the stage on which the micro LED panel is mounted, the presence or absence of a reference point within the micro LED panel for determining the position of the micro LED chip, and the size of the micro LED chip. means of solving the problem

[0008] To achieve the above objective, the alignment inspection device for a micro LED panel according to the present invention comprises: a stage on which a micro LED panel having an array of micro LED chips is placed and which is movable along the X-axis and Y-axis; a shooting unit that captures an image of an inspection area in which at least a preset number of micro LED chips are arranged on the micro LED panel placed on the stage; and a control unit that measures the relative distance between the micro LED chips within the inspection area based on the image and determines the suitability of the alignment of the micro LED chips in the inspection area based on the measured distance.

[0009] The control unit may include: a distance measuring unit that recognizes the micro LED chips within the inspection area based on the image and measures the relative distance between the micro LED chips; and a judgment unit that calculates an average value, a standard deviation, and a standard error based on the design value of the distance between the micro LED chips for the measured distance, and determines the suitability of the alignment of the micro LED chips in the inspection area according to at least one of the average value, the standard deviation, and the standard error.

[0010] The above distance measuring unit can measure the distance between the vertices of the micro LED chip.

[0011] The distance measuring unit can measure the distance between the vertices of the micro LED chip at least two points.

[0012] The distance measuring unit can measure the distance between vertices facing each other between adjacent micro LED chips.

[0013] The above inspection area may include a boundary surface between transfer areas formed by the transfer process of the micro LED chip.

[0014] The above judgment unit determines that the alignment of the micro LED chips within the inspection area is suitable when the difference between the average value and the design value of the distance between the micro LED chips is less than or equal to a preset value and the standard deviation is less than or equal to a preset value, and determines that the alignment of the micro LED chips within the inspection area is unsuitable when the difference between the average value and the design value exceeds a preset value or the standard deviation exceeds a preset value.

[0015] The above judgment unit may determine that the alignment of the micro LED chip within the inspection area is suitable when the standard error is less than or equal to a preset value, and determine that the alignment of the micro LED chip within the inspection area is unsuitable when the standard error exceeds a preset value.

[0016] A method for inspecting alignment of a micro LED panel according to the present invention comprises: a step in which an alignment inspection device captures an image of an inspection area in which more than a predetermined number of micro LED chips are arranged on a micro LED panel in which micro LED chips are arranged; a step in which the alignment inspection device measures the relative distance between the micro LED chips within the inspection area based on the image; and a step in which the alignment inspection device determines the suitability of the alignment of the micro LED chips in the inspection area based on the measured distance.

[0017] The step of measuring the distance may include: the step of the alignment inspection device recognizing the vertices of each micro LED chip within the inspection area; and the step of the alignment inspection device measuring the distance between the vertices of the micro LED chips.

[0018] The step of measuring the distance above allows the alignment inspection device to measure the distance between the vertices of the micro LED chip at least two points.

[0019] The step of measuring the distance above allows the alignment inspection device to measure the distance between vertices facing each other between neighboring micro LED chips.

[0020] The above inspection area may include a boundary surface between transfer areas formed by the transfer process of the micro LED chip.

[0021] The above-mentioned determination step may include: a step in which the alignment inspection device calculates an average value and a standard deviation for the measured distance of the inspection area; a step in which the alignment inspection device determines whether the difference between the average value and the design value of the distance between the micro LED chips is less than or equal to a preset value; and a step in which the alignment inspection device determines that the alignment of the micro LED chips within the inspection area is suitable if the standard deviation is less than or equal to a preset value, and determines that the alignment of the micro LED chips within the inspection area is unsuitable if the standard deviation exceeds a preset value.

[0022] The above-mentioned determination step may include: a step in which the alignment inspection device calculates a standard error for the measured distance based on a design value of the distance between the micro LED chips; and a step in which the alignment inspection device determines that the alignment of the micro LED chips within the inspection area is suitable if the standard error is less than or equal to a preset value, and determines that the alignment of the micro LED chips within the inspection area is unsuitable if the standard error exceeds a preset value. Effects of the invention

[0023] The present invention can inspect the alignment of micro LED chips within a micro LED panel regardless of the positional precision of the stage on which the micro LED panel is mounted, the presence or absence of a reference point within the micro LED panel for determining the position of the micro LED chips, and the size of the micro LED chips by measuring the relative distance between micro LED chips.

[0024] In other words, the present invention can check the error between each transfer process as well as a single transfer process, and determine the suitability of the alignment of micro LED chips. Brief explanation of the drawing

[0025] FIG. 1 is a block diagram showing an alignment inspection device according to an embodiment of the present invention. FIG. 2 is a drawing showing a micro LED panel according to an embodiment of the present invention. FIGS. 3 and FIGS. 4 are drawings showing examples of inspection areas of a micro LED panel according to an embodiment of the present invention. FIG. 5 is a diagram showing an example of an alignment inspection device according to an embodiment of the present invention determining the suitability of alignment based on standard deviation. FIG. 6 is a flowchart illustrating an alignment inspection method according to an embodiment of the present invention. FIG. 7 is a diagram showing the distance measurement step between micro LED chips of an alignment inspection method according to an embodiment of the present invention. FIG. 8 is a diagram showing the step of determining the suitability of alignment of a micro LED chip in an alignment inspection method according to an embodiment of the present invention. Specific details for implementing the invention

[0026] It should be noted that in the following description, only the parts necessary for understanding the embodiments of the present invention are explained, and the description of other parts will be omitted to the extent that it does not deviate from the gist of the present invention.

[0027] The terms and words used in the specification and claims described below should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely preferred embodiments of the invention and do not represent all aspects of the technical spirit of the invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0028] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings.

[0029] FIG. 1 is a block diagram showing an alignment inspection device according to an embodiment of the present invention.

[0030] Referring to FIG. 1, an alignment inspection device (100) according to an embodiment includes a stage (10) on which a micro LED panel with micro LED chips arranged thereon is placed, a shooting unit (20) for capturing an image of an inspection area in which micro LED chips are arranged on a micro LED panel placed on the stage (10), and a control unit (30) for measuring the relative distance between micro LED chips within the inspection area based on the image and determining the suitability of the alignment of micro LED chips in the inspection area based on the measured distance.

[0031] FIG. 2 is a drawing showing a micro LED panel according to an embodiment of the present invention.

[0032] Referring to FIG. 2, a micro LED panel (70) according to an embodiment may have a transfer area formed on a backplane substrate (71) in which a plurality of micro LED chips are transferred by an interposer. The interposer is a temporary substrate that is aligned to facilitate the separation of micro LED chips from a wafer and their transfer onto the backplane substrate (71). Generally, since the size of the interposer is smaller than that of the backplane substrate (71), multiple transfer processes are required to manufacture the micro LED panel (70). That is, as shown in FIG. 2, a single transfer area can be formed on the backplane substrate (71) through a single transfer process, and the micro LED panel (70) can be formed by repeating the transfer process. At this time, some micro LED chips may deviate from their design positions due to variations in elasticity and adhesion between the interposer and the micro LED chips, and between the backplane substrate and the micro LED chips, during a single transfer process. Furthermore, errors in the transfer position may occur between transfer processes while performing multiple transfer processes. Therefore, it is important to check for errors not only in a single transfer process but also between each transfer process.

[0033] The alignment inspection device (100) according to the embodiment can determine the suitability of the alignment of the micro LED chips by measuring the relative distance between micro LED chips on the micro LED panel (70), as well as the error between each transfer process and the single transfer process.

[0034] Hereinafter, the configuration of the alignment inspection device (100) according to the embodiment will be described in more detail.

[0035] A stage (10) is configured to accommodate a micro LED panel with arranged micro LED chips, and can move along the X and Y axes so that the micro LED panel mounted on the stage (10) is positioned at the bottom of the imaging unit (20). For example, the stage (10) may be configured to move along the X and Y axes by having a sliding part and a transfer part positioned at the bottom that are movable along the X and Y axes. Preferably, the stage (10) may be a device generally known as a UVW stage, but is not limited thereto.

[0036] The imaging unit (20) is positioned on the upper part of the stage (10) and can capture an image of the inspection area on a micro LED panel mounted on the stage (10). The imaging unit (20) may include an area camera and a microscope optical system, but is not limited thereto. Similar to the stage (10), the imaging unit (20) may have a sliding part and a transfer part positioned on the upper part that are movable along the X-axis and Y-axis, allowing it to move along the X-axis and Y-axis.

[0037] FIGS. 3 and FIGS. 4 are drawings showing examples of inspection areas of a micro LED panel according to an embodiment of the present invention.

[0038] Referring to FIGS. 1 to 4, the inspection area (73) may be an area where more than a predetermined number of micro LED chips (75) are arranged on the micro LED panel (70). For example, the inspection area (73) may be an area where 6 x 6 micro LED chips (75) are arranged.

[0039] The inspection area (73) may be selected based on information about the previously stored micro LED panel (70) or designated by the user. At this time, the inspection area (73) may include the boundary surface between the transfer areas formed by the transfer process of the micro LED chip (75), such as the second, fifth, and eighth inspection areas (73).

[0040] The micro LED panel (70) according to the embodiment may have errors between transfer processes through multiple transfer processes. Therefore, the alignment inspection device (100) according to the embodiment can check for errors between transfer processes by measuring the distance between micro LED chips (75) in an inspection area (73) that includes the boundary surface between transfer areas of the micro LED panel (70).

[0041] The control unit (30) includes a distance measuring unit (31) and a judgment unit (32), and can measure the relative distance between micro LED chips within an inspection area based on an image captured by a shooting unit, and determine the suitability of the alignment of micro LED chips in the inspection area based on the measured distance.

[0042] Specifically, the distance measuring unit (31) can recognize micro LED chips (75) within the inspection area (73) based on an image captured by the shooting unit and measure the distance between micro LED chips (75). For example, the distance measuring unit (31) can measure the distance between micro LED chips (75) by measuring the distance between the vertices of the micro LED chips (75), and preferably, the distance between the vertices of the micro LED chips (75) can be measured at least two points.

[0043] When measuring the distance based on the center of the micro LED chip (75) or measuring the distance between the vertices of the micro LED chip (75) at a single point, it may be difficult to determine if the micro LED chip (75) has rotated relative to the center or a single vertex and has deviated from the design position. Therefore, the distance measuring unit (31) according to the embodiment can measure the distance between the vertices of the micro LED chip (75) at least two points.

[0044] Additionally, the distance measuring unit (31) can measure the distance between vertices facing each other between neighboring micro LED chips (75). Specifically, as shown in FIG. 4, when first to fourth micro LED chips (75a, 75b, 75c, 75d) exist within the inspection area (73), the distance measuring unit (31) can measure the distance between the first micro LED chip (75a) and the second micro LED chip (75b), between the first micro LED chip (75a) and the third micro LED chip (75c), between the second micro LED chip (75b) and the fourth micro LED chip (75d), and between the third micro LED chip (75c) and the fourth micro LED chip (75d). At this time, the distance measuring unit (31) can measure the distance between vertices of the first to fourth micro LED chips (75a, 75b, 75c, 75d) at least two points, and preferably, can measure the distance between vertices facing each other between neighboring micro LED chips (75).

[0045] In an embodiment of the present invention, the distance between neighboring micro LED chips (75) in the same row or column is measured, but is not limited thereto. In another embodiment of the present invention, the distance between two micro LED chips (75) can be measured, which are spaced apart at a certain interval in the same row or column, with 1 to 4 micro LED chips (75) existing in the spaced-away space. In yet another embodiment of the present invention, the distance between micro LED chips (75) located in different rows and columns can be measured.

[0046] In addition, in an embodiment of the present invention, the distance between vertices facing each other between neighboring micro LED chips (75) is measured, but is not limited thereto. In other embodiments of the present invention, the distance between vertices in staggered positions or the distance between vertices in corresponding positions may be measured.

[0047] The distance measuring unit (31) can measure the distance between the vertices of the micro LED chips (75) by using deep learning such as image segmentation to recognize the micro LED chips (75) within the inspection area (73) and extracting the coordinates of the vertices within the image. The method by which the distance measuring unit (31) measures the distance between the micro LED chips (75) is not limited to this.

[0048] Generally, the position of the micro LED chip (75) can be determined based on the pattern on the backplane substrate (71), and the alignment of the micro LED chip (75) can be verified. However, the position information of the micro LED chip (75) depends on the positional precision of the stage (10) on which the micro LED panel (70) is mounted, and there is a problem that the error increases as the size of the micro LED chip (75) becomes smaller. In addition, once the attachment of the micro LED chip (75) to the backplane substrate (71) is completed, the pattern on the backplane substrate (71) becomes invisible due to the micro LED chip (75), so there is a problem that it is difficult to determine the position information of the micro LED chip (75).

[0049] However, the alignment inspection device (100) according to the embodiment can inspect the alignment of the micro LED chips (75) within the micro LED panel (70) regardless of the positional precision of the stage (10) on which the micro LED panel (70) is mounted, the presence or absence of a reference point on the micro LED panel (70) for determining the position of the micro LED chips (75), and the size of the micro LED chips (75) by measuring the relative distance between the micro LED chips (75).

[0050] The judgment unit (32) measures the distance (d1, d2, …, d) between micro LED chips (75) in the inspection area (73). nThe average value, standard deviation, and standard error based on the design value of the distance between the micro LED chips (75) can be calculated using the variable ) for the measured distance. And the judgment unit (32) can determine the suitability of the alignment of the micro LED chips (75) in the inspection area (73) according to at least one of the average value, standard deviation, and standard error.

[0051] The judgment unit (32) can determine that the alignment of the micro LED chips (75) within the inspection area is suitable if the difference between the average value and the design value of the distance between the micro LED chips (75) is less than or equal to a preset value and the standard deviation is less than or equal to a preset value. Additionally, the judgment unit (32) can determine that the alignment of the micro LED chips (75) within the inspection area (73) is unsuitable if the difference between the average value and the design value exceeds a preset value or if the standard deviation exceeds a preset value.

[0052] Since the average value of the measured distance includes the measurement error of the alignment inspection device (100) itself, it is difficult to accurately determine the alignment suitability of the micro LED chip (75) based solely on the difference between the average value and the design value. Therefore, it is desirable to determine the alignment suitability of the micro LED chip (75) by considering not only the difference between the average value of the measured distance and the design value but also the standard deviation. Here, the standard deviation is a value that indicates the degree to which variables are scattered relative to the average value, and can be calculated as shown in [Equation 1] below.

[0053]

[0054] Here, d d represents the design value of the distance between micro LED chips, and d i represents the distance between micro LED chips measured by the distance measuring unit (31). That is, if the difference between the average value and the design value is small, it can be determined that the variable is evenly distributed around the design value.

[0055] FIG. 5 is a diagram showing an example of an alignment inspection device according to an embodiment of the present invention determining the suitability of alignment based on standard deviation.

[0056] Referring to FIG. 5, the alignment inspection device (100) according to the embodiment can determine that the alignment of micro LED chips within an inspection area is suitable when the standard deviation is 30 μm or less, and determine that the alignment of micro LED chips within an inspection area is unsuitable when the standard deviation exceeds 30 μm. That is, the alignment of micro LED chips in the first to fourth inspection areas, the sixth inspection area, the seventh inspection area, and the ninth inspection area can be determined to be suitable because the standard deviation is 30 μm or less, and the alignment of micro LED chips in the fifth and eighth inspection areas can be determined to be unsuitable because the standard deviation exceeds 30 μm. These criteria may vary depending on the size of the micro LED chips and the design values ​​of the distance between micro LED chips, but are not limited thereto.

[0057] A judgment unit (32) according to another embodiment of the present invention may determine that the alignment of the micro LED chip (75) within the inspection area (73) is suitable when the standard error is less than or equal to a preset value, and determine that the alignment of the micro LED chip (75) within the inspection area (73) is unsuitable when the standard error exceeds a preset value. Here, the standard error is a value indicating the degree to which variables are scattered relative to the design value, and can be calculated as shown in [Equation 2] below.

[0058]

[0059] Here, d a represents the average value of the distance between micro LED chips measured by the distance measuring unit (31), and d irepresents the distance between micro LED chips measured by the distance measuring unit (31). That is, the smaller the standard error, the more evenly the variables are distributed around the design value.

[0060] The judgment unit (32) according to the present invention is not limited thereto and may determine the suitability of the alignment of the micro LED chip (75) according to the average value and standard error, or determine the suitability of the alignment of the micro LED chip (75) according to the average value, standard deviation, and standard error. In addition, the judgment unit (32) according to the present invention may determine the suitability of the alignment of the micro LED chip (75) according to statistical figures such as other representative values ​​and dispersions in addition to the average value, standard deviation, and standard error.

[0061] The control unit (30) can not only determine the suitability of the alignment of the micro LED chip (75) but also control the overall operation of the alignment inspection device (100). In particular, when the judgment unit (32) determines the suitability of the alignment of the inspection area, the control unit (30) can control the movement of the stage (10) or the shooting unit (20) so that the shooting unit (20) can photograph another inspection area.

[0062] The storage unit (40) is a device for storing data and stores applications necessary for the functional operation of the alignment inspection device (100). When the storage unit (40) activates each function in response to a user's request, it executes applications under the control of the control unit (30) to provide each function. This storage unit (40) may include at least one storage medium among a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory, etc.), RAM (Random Access Memory), SRAM (Static Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory), magnetic memory, a magnetic disk, and an optical disk. In particular, the storage unit (40) can store design values ​​for the distance between micro LED chips, information about the micro LED panel, a program capable of measuring the distance between micro LED chips, and a program capable of determining the suitability of the alignment of micro LED chips from the measured distance between micro LED chips.

[0063] The input unit (not shown) receives various information such as numerical and character information, and can transmit signals input in relation to setting various functions or controlling the functions of the alignment inspection device (100) to the control unit (30). The input unit (not shown) may be configured to include at least one of a keypad and a touchpad that generates input signals according to touch or operation. In this case, the input unit (not shown) may be configured in the form of a single touch panel (or touchscreen) together with a display unit (not shown) to simultaneously perform the functions of input and display. In particular, the input unit (not shown) may receive input signals for operating the alignment inspection device (100), input data for controlling the position of the stage (10), etc., from the user.

[0064] A display unit (not shown) displays information regarding a series of operating states, operating results, etc. that occur during the performance of the function of the alignment inspection device (100). Such a display unit (not shown) may be composed of a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT LCD), an organic light-emitting diode (OLED), a flexible display, and a 3D display. In this case, if the display unit (not shown) is configured in the form of a touchscreen, it may perform some or all of the functions of an input unit (not shown). In particular, the display unit (not shown) may output an image captured by the shooting unit (20), output data regarding the distance between micro LED chips measured by the distance measuring unit (31), or output data determining the suitability of the alignment of micro LED chips within the inspection area.

[0065] Hereinafter, an alignment inspection method according to an embodiment will be described in more detail.

[0066] FIG. 6 is a flowchart illustrating an alignment inspection method according to an embodiment of the present invention.

[0067] Referring to FIG. 6, the alignment inspection method according to the embodiment first takes an image of an inspection area on a micro LED panel on which micro LED chips are arranged in step S10.

[0068] In this case, the inspection area is an area where more than a preset number of micro LED chips are arranged, and it can be selected based on information about a pre-stored micro LED panel or specified by the user. In particular, the inspection area may include the boundary surface between transfer areas formed by the transfer process of the micro LED chips. Accordingly, the alignment inspection method according to the embodiment can check the error between each transfer process as well as a single transfer process, and determine the suitability of the alignment of the micro LED chips.

[0069] Next, in step S20, the alignment inspection device measures the distance between micro LED chips within the inspection area based on the image.

[0070] FIG. 7 is a diagram showing the distance measurement step between micro LED chips of an alignment inspection method according to an embodiment of the present invention.

[0071] Referring to FIG. 7, in the alignment inspection method according to the embodiment, at step S21, the alignment inspection device can recognize each micro LED chip within the inspection area.

[0072] Next, in step S23, the alignment inspection device can measure the distance between the vertices of the micro LED chips.

[0073] At this time, the alignment inspection device can measure the distance between vertices at at least two points. If the distance is measured based on the center of the micro LED chip or the distance between the vertices of the micro LED chip is measured at a single point, it may be difficult to determine if the micro LED chip has rotated relative to the center or a single vertex and has deviated from its design position. Therefore, the alignment inspection device according to the embodiment can measure the distance between vertices at at least two points, and preferably, can measure the distance between vertices facing each other between neighboring micro LED chips.

[0074] In an embodiment of the present invention, the distance between neighboring micro LED chips in the same row or column is measured, but is not limited thereto. In another embodiment of the present invention, the distance between two micro LED chips can be measured, which are spaced apart at a certain interval in the same row or column, with 1 to 4 micro LED chips existing in the spaced-apart space. In yet another embodiment of the present invention, the distance between micro LED chips located in different rows and columns can be measured.

[0075] In an embodiment of the present invention, the distance between vertices facing each other between neighboring micro LED chips is measured, but is not limited thereto. In another embodiment of the present invention, the distance between vertices in staggered positions or the distance between vertices in corresponding positions may be measured.

[0076] Finally, in step S30, the suitability of the alignment of the micro LED chips in the inspection area is determined based on the distance measured by the alignment inspection device.

[0077] FIG. 8 is a diagram showing the step of determining the suitability of alignment of a micro LED chip in an alignment inspection method according to an embodiment of the present invention.

[0078] Referring to FIG. 8, the alignment inspection method according to the embodiment can first calculate the average value and standard deviation of the distance measured by the alignment inspection device in step S31.

[0079] Next, in step S32, the alignment inspection device can determine whether the difference between the average value and the design value is less than or equal to a preset value. If the difference between the average value and the design value exceeds the preset value, the alignment of the micro LED chips within the inspection area can be determined to be unsuitable; if the difference between the average value and the design value is less than or equal to the preset value, in step S33, it can determine whether the standard deviation is less than or equal to a preset value.

[0080] Since the average value of the measured distance includes the measurement error of the alignment inspection device itself, it is difficult to accurately determine the alignment suitability of micro LED chips based solely on the difference between the average and design values. Therefore, it is advisable to determine the alignment suitability of micro LED chips by considering not only the difference between the average and design values ​​but also the standard deviation.

[0081] Finally, in step S33, the alignment inspection device may determine that the alignment of the micro LED chips within the inspection area is suitable if the standard deviation is less than or equal to a preset value, and determine that the alignment of the micro LED chips within the inspection area is unsuitable if the standard deviation exceeds a preset value.

[0082] Standard deviation is a value that indicates the degree to which variables are scattered relative to the mean; the smaller the standard deviation, the more evenly the variables are distributed around the mean. In other words, if the difference between the mean and the design value is small, it can be concluded that the variables are evenly distributed around the design value.

[0083] In the step of determining the suitability of the alignment of micro LED chips in the alignment inspection method according to another embodiment of the present invention, the alignment inspection device calculates a standard error for the distance measured based on the design value of the distance between micro LED chips, and if the standard error is less than or equal to a preset value, the alignment of the micro LED chips within the inspection area is determined to be suitable, and if the standard error exceeds the preset value, the alignment of the micro LED chips within the inspection area is determined to be unsuitable. Here, since the standard error is a value indicating the degree to which variables are scattered relative to the design value, it can be determined that the smaller the standard error, the more evenly the variables are distributed around the design value.

[0084] Meanwhile, the embodiments disclosed in this specification and drawings are merely specific examples provided to aid understanding and are not intended to limit the scope of the invention. It is obvious to those skilled in the art that other variations based on the technical concept of the invention are possible in addition to the embodiments disclosed herein. Explanation of the symbols

[0085] 100: Alignment inspection device 10: Stage 20 : Filming Department 30: Distance measuring unit 40 : Judgment Division 50 : Control unit 60 : Storage section 70 : Micro LED panel 71 : Backplane board 73 : Test area 75 : Micro LED chip

Claims

Claim 1 A micro LED panel alignment inspection device comprising: a stage movable along the X-axis and Y-axis, on which a micro LED panel having arranged micro LED chips is mounted; a shooting unit that captures an image of an inspection area in which more than a preset number of said micro LED chips are arranged on the micro LED panel mounted on the stage; and a control unit that measures the relative distance between said micro LED chips within the inspection area based on the image and determines the suitability of the alignment of said micro LED chips in the inspection area based on the measured distance; wherein the control unit comprises: a distance measuring unit that recognizes said micro LED chips within the inspection area based on the image and measures the relative distance between said micro LED chips; and a judgment unit that calculates an average value, a standard deviation, and a standard error based on a design value of the distance between said micro LED chips for the measured distance, and determines the suitability of the alignment of said micro LED chips in the inspection area according to at least one of said average value, standard deviation, and standard error; wherein the distance measuring unit measures the distance between the vertices of said micro LED chips. Claim 2 delete Claim 3 delete Claim 4 A micro LED panel alignment inspection device according to claim 1, wherein the distance measuring unit measures the distance between the vertices of the micro LED chip at least two points. Claim 5 In claim 4, the distance measuring unit is characterized by measuring the distance between vertices facing each other between adjacent micro LED chips, forming an alignment inspection device for a micro LED panel. Claim 6 A micro LED panel alignment inspection device according to claim 1, characterized in that the inspection area includes a boundary surface between transfer areas formed by a transfer process of the micro LED chip. Claim 7 A micro LED panel alignment inspection device according to claim 1, wherein the judgment unit determines that the alignment of the micro LED chips within the inspection area is suitable when the difference between the average value and the design value of the distance between the micro LED chips is less than or equal to a preset value and the standard deviation is less than or equal to a preset value, and determines that the alignment of the micro LED chips within the inspection area is unsuitable when the difference between the average value and the design value exceeds a preset value or the standard deviation exceeds a preset value. Claim 8 A micro LED panel alignment inspection device according to claim 1, wherein the judgment unit determines that the alignment of the micro LED chips within the inspection area is suitable when the standard error is less than or equal to a preset value, and determines that the alignment of the micro LED chips within the inspection area is unsuitable when the standard error exceeds a preset value. Claim 9 A method for inspecting the alignment of a micro LED panel, comprising: a step in which an alignment inspection device captures an image of an inspection area in which more than a predetermined number of micro LED chips are arranged on a micro LED panel in which micro LED chips are arranged; a step in which the alignment inspection device measures the relative distance between the micro LED chips within the inspection area based on the image; and a step in which the alignment inspection device determines the suitability of the alignment of the micro LED chips in the inspection area based on the measured distance; wherein the step of measuring the distance includes: a step in which the alignment inspection device recognizes each micro LED chip within the inspection area; and a step in which the alignment inspection device measures the distance between the vertices of the micro LED chips. Claim 10 delete Claim 11 In claim 9, the step of measuring the distance is characterized in that the alignment inspection device measures the distance between the vertices of the micro LED chips at least two points. Claim 12 A method for inspecting alignment of a micro LED panel according to claim 11, wherein the step of measuring the distance is characterized in that the alignment inspection device measures the distance between vertices facing each other between adjacent micro LED chips. Claim 13 A method for inspecting alignment of a micro LED panel according to claim 9, wherein the inspection area includes a boundary surface between transfer areas formed by a transfer process of the micro LED chip. Claim 14 A method for inspecting alignment of a micro LED panel according to claim 9, wherein the determining step comprises: a step in which the alignment inspection device calculates an average value and a standard deviation for the measured distance of the inspection area; a step in which the alignment inspection device determines whether the difference between the average value and the design value of the distance between the micro LED chips is less than or equal to a preset value; and a step in which the alignment inspection device determines that the alignment of the micro LED chips within the inspection area is suitable if the standard deviation is less than or equal to a preset value, and determines that the alignment of the micro LED chips within the inspection area is unsuitable if the standard deviation exceeds a preset value. Claim 15 A method for inspecting alignment of a micro LED panel according to claim 9, wherein the determining step comprises: a step in which the alignment inspection device calculates a standard error for the measured distance based on a design value of the distance between the micro LED chips; and a step in which the alignment inspection device determines that the alignment of the micro LED chips within the inspection area is suitable if the standard error is less than or equal to a preset value, and determines that the alignment of the micro LED chips within the inspection area is unsuitable if the standard error exceeds a preset value.

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