Scribing workpiece processing area depth measuring method, and measuring method

Abstract

To provide a scribing workpiece processing area depth measuring method for precisely measuring the depth of a processing area formed on a surface of an object body.SOLUTION: A scribing workpiece processing area depth measuring method includes: acquiring a surface image of an object body OB that is a workpiece having a processed surface, from an image sensor unit 120 of an imaging unit provided with a lens unit 110; detecting a first position P1 of the lens unit focused on a first area A1 that is separated from the processing area on the surface image; detecting a second position P2 of the lens unit focused on a second area A2 where the processing area G is located on the surface image; and measuring the depth of the processing area by using the distance D between the first position and the second position of the lens unit. The first position and the second position of the lens unit are determined by a contrast ratio measured by the movement of the lens unit.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a method for measuring the depth of a processed region of a scribing workpiece, and a measuring method. [Background technology]

[0002] Generally, in the process of manufacturing products such as displays, a protective film is attached to the surface of the product using a pressure sensitive adhesive (PSA), which protects the surface of the product from external factors such as external contaminants and scratches, thereby improving the quality of the product.

[0003] After the protective film is attached, a predetermined area of ​​the protective film needs to be removed in order to perform a post-processing step. The removal of the protective film is generally performed by a scribing process using a laser.

[0004] When removing the film using a laser, the laser processing is performed at a depth that does not cause damage to the product underneath the film; specifically, the adhesive underneath the film is cut to maintain a preset thickness.

[0005] In this case, the remaining amount of adhesive is determined by the initial thickness information of the film and adhesive, and the remaining amount can be adjusted by changing the laser output and the focal length of the processing lens.

[0006] Conventionally, to measure the amount of remaining adhesive during a laser process, the film to be measured was cut and the cross section was checked one by one through a separate microscope. However, this had the problem of taking a long time to cut the film during the process and detect the depth one by one. Summary of the Invention Problem to be solved

[0007] The technical problem to be solved by the present invention is to provide a method for measuring the depth of a processed area of ​​a scribing workpiece, which can precisely measure the depth of a processed area formed on the surface of a target object by detecting the positions of lens units each of which is focused on a different area by a control unit. [Means for solving the problem]

[0008] One aspect of the present invention provides a method for measuring the depth of a processed area of ​​a scribing workpiece, the method including the steps of: acquiring a surface image of a target object having a processed surface from an imaging unit having a lens unit; detecting a first position of the lens unit focused on a first area on the surface image that is away from a processed area; detecting a second position of the lens unit focused on a second area on the surface image in which the processed area is located; and measuring the depth of the processed area using the first and second positions of the lens unit, wherein the first and second positions of the lens unit are determined by a contrast ratio measured as the lens unit moves.

[0009] In addition, the step of detecting the first position of the lens portion may further include a step of setting a region of the surface image, including both the first region and the second region, as a first focal region.

[0010] In addition, the step of detecting a first position of the lens unit can include performing a contrast autofocus operation for the first focal area, and detecting the position of the lens unit when the contrast ratio of the first focal area is maximum as the first position.

[0011] Additionally, the center of the first focal area may coincide with the center of the processing area.

[0012] In addition, the step of detecting a second position of the lens portion includes a step of acquiring position information of the processing area, and a step of setting a region of the surface image as a second focal area based on the acquired position information of the processing area, and the second focal area may be included in the second area.

[0013] In addition, the step of detecting the second position of the lens unit can include performing a contrast autofocus operation for the second focal area, and detecting the position of the lens unit when the contrast ratio of the second focal area is maximum as the second position.

[0014] Additionally, the center of the first focal region and the center of the second focal region may coincide.

[0015] In addition, an angle between a normal vector of the surface of the target object, which passes through the center of the processing area, and the optical axis of the lens portion may be 5° or less.

[0016] The lens portion may be movable along a preset movement axis, and the movement axis may be perpendicular to a surface of the object.

[0017] Furthermore, in the step of measuring the depth of the processed region, the depth of the processed region can be calculated using a difference between the first position and the second position of the lens portion.

[0018] Another aspect of the present invention provides an apparatus for measuring the depth of a processed region of a scribing workpiece, comprising: an imaging unit for acquiring a surface image of a target object having a processed surface; a lens unit disposed between the imaging unit and the target object and movable in one direction perpendicular to the surface of the target object; and a control unit for controlling the movement of the lens unit, wherein the control unit is capable of measuring the contrast ratio of the surface image acquired by moving the lens unit in the one direction.

[0019] In addition, the control unit is capable of detecting the position of the lens unit focused on a first area spaced from the processing area on the surface of the target object, and the position of the lens unit focused on a second area in which the processing area is located, and can measure the depth of the processing area using the position of the lens unit focused on the first area and the position of the lens unit focused on the second area in which the processing area is located. Effect of the Invention

[0020] The method for measuring the depth of a processed area of ​​a scribing workpiece according to one embodiment of the present invention has the effect of quickly and accurately measuring the depth of a processed area formed on the surface of an object by measuring the contrast ratio by changing the focal area of ​​an imaging unit that photographs the object. In addition, by detecting in advance defects that occur due to errors in processing strength caused by unintentional motion of the output laser during the product production process, production yields can be improved. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a configuration diagram showing an example of an apparatus for measuring the depth of a processed region of a scribed workpiece according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram for explaining a step in which a control unit sets the first and second focal regions according to an embodiment of the present invention. [Diagram 3] 3a to 3c are diagrams illustrating steps in which the control unit detects a first position of the lens unit where the focus is on the first region according to an embodiment of the present invention. [Figure 4] 4a to 4c are diagrams illustrating a step in which the control unit detects a second position of the lens unit where the focus is on the second region according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a diagram for explaining a step in which the control unit measures the depth of the processed region using the first position and the second position of the lens unit according to an embodiment of the present invention. [Figure 6]FIG. 6 is a flow chart of a method for measuring the depth of a processed region of a scribing workpiece according to one embodiment of the present invention. [Figure 7] FIG. 7 is a flow chart of a method for detecting a first position of a lens portion according to an embodiment of the present invention. [Figure 8] FIG. 8 is a flow chart of a method for detecting a second position of a lens portion according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments are shown in the drawings and will be described in detail from the detailed description. The effects and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described in detail below together with the drawings. However, the present invention is not limited to the embodiments disclosed below and can be realized in various forms.

[0023] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the drawings, the same or corresponding components are given the same reference numerals, and duplicate descriptions thereof will be omitted.

[0024] In the following embodiments, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0025] In the following embodiments, terms such as "comprise" or "have" mean the presence of features or components described in this specification, and do not preclude the possibility that one or more other features or components may be added.

[0026] When an embodiment is otherwise feasible, the order of certain steps may be performed out of the order described, for example two steps described as successive may be performed substantially simultaneously or in the reverse order from that described.

[0027] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the following embodiments are not necessarily limited to those shown in the drawings.

[0028] In the description of each component, when it is stated that the component is formed on or under, the terms on and under include those that are formed directly or via other components, and the reference to on and under will be described with reference to the drawings.

[0029] FIG. 1 is a block diagram showing an example of an apparatus for measuring the depth of a processed region of a scribed object according to an embodiment of the present invention. FIG. 2 is a diagram for explaining a step in which a control unit according to an embodiment of the present invention sets first and second focal regions. FIGS. 3a to 3c are diagrams for explaining a step in which a control unit according to an embodiment of the present invention detects a first position P1 of a lens unit where the focus is on the first region. FIGS. 4a to 4c are diagrams for explaining a step in which a control unit according to an embodiment of the present invention detects a second position P2 of a lens unit where the focus is on the second region. FIG. 5 is a diagram for explaining a step in which a control unit according to an embodiment of the present invention measures the depth of a processed region using the first position P1 and the second position P2 of the lens unit.

[0030] In the manufacturing process of products where surface quality is important, such as display panels (PN) and wafers, it is common to apply film F to the surface of the product to prevent degradation of surface quality due to surface contamination or crack damage.

[0031] In order to firmly fix the film F to the surface of the product, an adhesive AD is laminated between the product surface and the film F, and after the film F has been attached, a predetermined area of ​​the film F is required to be removed in order to carry out a post-processing step.

[0032] In order to remove a predetermined area of ​​the film F, the film F is cut using a laser or grinding process, and at this time, the laser or grinding process is performed so that a predetermined thickness of the adhesive AD remains under the film F to prevent damage to the product surface.

[0033] In this case, in order to precisely cut the ultra-thin film F while preventing damage to the product surface, it is necessary to precisely measure the remaining thickness of the adhesive AD during the cutting process, and in order to precisely measure the remaining thickness of the adhesive AD, it is necessary to precisely measure the depth of the processing area G of the groove formed by laser or grinding processing.

[0034] The scribing workpiece processing area depth measuring device 1 (hereinafter referred to as the "processing area depth measuring device") according to one embodiment of the present invention is a device for measuring the depth of a groove processing area G formed on the surface of an object OB by laser processing, grinding processing, or the like.

[0035] In this specification, the "object OB" may be interpreted as a panel PN to which a film F is attached. Specifically, the "object OB" may be interpreted as a display panel PN to which an adhesive layer AD and a film F layer are sequentially laminated on the surface.

[0036] However, it is not necessarily limited to this, and the "object OB" may be interpreted as various types of objects in which a processed area G such as a groove, modified area, or modified layer is formed on the surface by a scribing process such as laser processing or grinding.

[0037] For example, the "object OB" may be interpreted as a semiconductor wafer such as a silicon wafer, a silicon on insulator (SOI) wafer, a gallium arsenide wafer, or a silicon nitride wafer, or may be interpreted as a glass wafer.

[0038] The processed area depth measuring device 1 and processed area depth measuring method according to one embodiment of the present invention can be used to measure the processed depth or the depth of a modified layer of an object OB formed in a scribing process, an etching process, a stealth dicing process, a cleaving process, etc. of an object OB such as a display panel PN, a semiconductor wafer, or a glass wafer.

[0039] Referring to FIG. 1, a processed region depth measuring device 1 according to an embodiment of the present invention may include an imaging unit 100, a driving unit 200, a control unit 300, and an illumination unit 400.

[0040] The imaging unit 100 according to an embodiment of the present invention obtains a surface image of an object OB whose surface has been processed to form a processing area G such as a groove, and can output surface image information to the control unit 300.

[0041] In this specification, the term "image" can be interpreted not only as a static image, but also as a dynamic video.

[0042] In one embodiment, the imaging unit 100 can detect wavelengths in red, green, and blue bands and generate digital codes (RGB) corresponding to the wavelengths of each band. However, without being limited thereto, the imaging unit 100 can detect wavelengths in various bands and generate digital codes preset to correspond to the wavelengths of each band.

[0043] The imaging unit 100 can amplify the electric signal and output image information corresponding to the amplified electric signal to the control unit 300. This has the effect of making it possible to obtain image information even in a low-illumination external environment.

[0044] The imaging unit 100 according to an embodiment of the present invention may acquire brightness information from a surface of an object OB. Specifically, the imaging unit 100 may acquire a surface image of the object OB, and each pixel value included in the surface image may include absolute or relative contrast information.

[0045] Contrast information for a region on the surface of the object OB can be calculated using the light intensity, lux value, etc., acquired by the imaging unit 100 from the region, and the control unit 300 can perform contrast autofocus operation using the contrast information of each pixel value contained in the surface image.

[0046] As an alternative embodiment, when the imaging unit 100 is an infrared camera, the imaging unit 100 can project infrared rays, and in this case, depth information regarding a target object can be generated based on the difference in phase value between the projected infrared rays and the reflected and received infrared rays. The cycle at which the imaging unit 100 projects the infrared rays may be continuous or may be discontinuous, and the cycle at which the imaging unit 100 projects the infrared rays may be preset.

[0047] As an alternative embodiment, the imaging unit 100 may be a stereo camera, and the imaging unit 100 may acquire visible light information acquired from a plurality of stereo cameras, and the control unit 300 may be provided with the acquired visible light information and generate depth information regarding a target object using a triangulation technique.

[0048] Referring to FIG. 1, an image capturing unit 100 according to an embodiment of the present invention may include a lens unit 110 and an image sensor unit 120.

[0049] The lens unit 110 collects light reflected from a surface image of the object OB on which a processing region G such as a groove is formed, and forms an image on the image sensor. The lens unit 110 may be made of various types of optical lenses.

[0050] In one embodiment, the lens unit 110 may receive power from the driving unit 200 and move along a preset movement axis, and the movement axis of the lens unit 110 may be perpendicular to the surface of the object OB.

[0051] Specifically, the optical axis of the lens unit 110 may be positioned to overlap with an area in which a processing area G, such as a groove, is located, and the lens unit 110 may move in a direction away from or toward the object OB.

[0052] In this specification, the "optical axis" of lens unit 110 may be interpreted as the axis of symmetry of lens unit 110. Specifically, the "optical axis" of lens unit 110 may be interpreted as an axis that passes through the center of lens unit 110 and connects the center points of curvature of the front and rear surfaces of lens unit 110.

[0053] According to an embodiment of the present invention, the movement axis of the lens unit 110 may be aligned with or parallel to the optical axis of the lens unit 110. As a result, even if the position of the lens unit 110 is changed along the movement axis, the lens unit 110 can receive light from the same area of ​​the object OB, and thus, as the lens unit 110 moves along the movement axis, a contrast ratio for the same area of ​​the object OB can be measured.

[0054] According to an embodiment of the present invention, the angle between the optical axis of the lens unit 110 and the normal vector of the surface of the object OB may be less than 5°.

[0055] As a result, even if the lens unit 110 moves along the movement axis, the center CL of the processing area G can always be included in the shooting area of ​​the imaging unit 100, so that the control unit 300 can acquire contrast information for the center CL of the processing area G and measure the depth of the center CL of the processing area G regardless of the position of the lens unit 110.

[0056] The movement axis of the lens portion 110 may pass through the center CL of the groove and may be arranged in the same direction as the normal vector of the surface of the object OB.

[0057] The lens unit 110 may be arranged so that its optical axis is aligned with the normal vector of the surface of the object OB, and the lens unit 110 may receive power from the driving unit 200 and move toward or away from the object OB depending on the normal vector of the surface of the object OB.

[0058] The image sensor unit 120 according to an embodiment of the present invention receives light received by the lens unit 110 and converts the light into an electrical signal, thereby obtaining a surface image of the object OB.

[0059] The image sensor unit 120 receives light received by the lens unit 110 and can obtain contrast information of a surface image of the object OB in units of one or more pixels.

[0060] Specifically, as the lens unit 110 moves along the movement axis, the amount of light that the lens unit 110 acquires from each part of the surface of the object OB changes, and the image sensor unit 120 can acquire contrast information of the surface image of the object OB that changes as the lens unit 110 moves.

[0061] The image sensor unit 120 may transmit contrast information of a surface image of the object OB to the control unit 300, and the control unit 300 may measure a contrast ratio using the contrast information of the surface image transmitted from the image sensor unit 120.

[0062] Referring to FIG. 1, a driving unit 200 according to an embodiment of the present invention is connected to one side of a lens unit 110 and can provide power to move the lens unit 110 along a preset movement axis.

[0063] In one embodiment, the driver 200 can transmit driving information to the controller 300, so that the controller 300 can precisely detect the position of the lens unit 110 on the movement axis using the driving information of the driver 200.

[0064] The control unit 300 according to an embodiment of the present invention can obtain a surface image of the object OB from the imaging unit 100 and measure the depth of the processing region G to be formed on the surface of the object OB.

[0065] The control unit 300 may be implemented using at least one of ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), controllers, micro-controllers, microprocessors, and electrical units for performing other functions.

[0066] The control unit 300 according to one embodiment of the present invention may include at least one or more volatile and / or non-volatile memories, and the memories may store instructions or data related to at least one other component of the processing area depth measuring device 1, specifically, the driving unit 200 and the imaging unit 100.

[0067] The control unit 300 may store software and / or programs. The programs may include, for example, a kernel, middleware, an application programming interface (API), and / or an application program (or “application”).

[0068] At least a part of the kernel, middleware, or API may be referred to as an operating system. The kernel may, for example, control or manage system resources (e.g., bus, processor, or memory) used to perform operations or functions implemented in other programs (e.g., middleware, API, or application programs). The kernel may also provide an interface that allows the middleware, API, or application programs to access individual components of the processing region depth measuring device 1 to control or manage system resources.

[0069] 1 and 2, a control unit 300 according to an embodiment of the present invention may set one area of ​​a surface image of an object OB where a processing area G is to be formed as a focus area FA1, FA2.

[0070] In this specification, "focal areas FA1, FA2" may be interpreted as areas of an image on which the contrast autofocus (contrast AF) operation of the control unit 300 is performed, and when a region of the surface image is set as focal area FA1, FA2, the control unit 300 can measure the contrast ratio of the surface image based on the set focal area FA1, FA2.

[0071] In one embodiment, the control unit 300 may receive a control command from an external device and set one area of ​​the surface image as the focus areas FA1 and FA2.

[0072] Specifically, the user can input information regarding the positions of the focal area centers C1, C2, the sizes of the focal areas FA1, FA2, etc. to the control unit 300, and the control unit 300 can receive the input of geometric information of the focal areas FA1, FA2 and set a region of the surface image as the focal area FA1, FA2.

[0073] In one embodiment, the control unit 300 may set one area of ​​the surface image as the focus areas FA1 and FA2 according to a preset algorithm.

[0074] 2, the control unit 300 may set one region of the surface image as the focal regions FA1, FA2 in accordance with a preset algorithm such that the centers C1, C2 are located in the region where the processing region G is located. Specifically, the control unit 300 may set one region of the surface image as the focal regions FA1, FA2 in accordance with a preset algorithm such that the centers C1, C2 overlap with the center CL of the processing region G.

[0075] The control unit 300 can fix the centers C1 and C2 of the focal areas to the area where the center CL of the processing area G is located according to a preset algorithm, and can change the size of the focal areas FA1 and FA2 by receiving a control command input from the outside.

[0076] Specifically, the control unit 300 can fix the center C1 of the first focal area and the center C2 of the second focal area to the area where the center CL of the processing area G is located according to a preset algorithm, and can receive input from the user regarding the size of the first focal area FA1 and set the size of the first focal area FA1 so that the first focal area FA1 includes all of the area where the processing area G is located and the surface area of ​​the target object OB where the processing area G is not located, and can receive input from the user regarding the size of the second focal area FA2 and set the size of the second focal area FA2 so that the second focal area FA2 locally includes only the area where the processing area G is located.

[0077] However, this is not limited thereto, and a detailed description of the method by which the control unit 300 sets the first focal area FA1 and the second focal area FA2 will be given in the description of the method for measuring the depth of the processing area of ​​the scribing workpiece.

[0078] Referring to Figures 2 and 3a to 4c, a control unit 300 according to an embodiment of the present invention can detect the position of the lens unit 110 that is focused on a certain area of ​​a surface image of an object OB, specifically, on a preset focal area FA1, FA2.

[0079] The control unit 300 according to an embodiment of the present invention is electrically connected to the driving unit 200 and the imaging unit 100, respectively, and can perform a contrast autofocus (contrast AF) operation on the surface area of ​​the object OB where the processing area G is to be formed.

[0080] Below, we will explain how the control unit 300 controls the driving of the driving unit 200 and acquires surface images of the focal areas FA1 and FA2 from the imaging unit 100 to perform contrast autofocus (contrast AF) operation on the surface area of ​​the target object OB where the processing area G is formed.

[0081] The control unit 300 can control the driving unit 200 to change the position of the lens unit 110. The lens unit 110 can receive light from a region on the surface of the object OB included in the focal areas FA1 and FA2 and transmit the light to the image sensor unit 120, through which the image sensor unit 120 can obtain a surface image of the object OB included in the focal areas FA1 and FA2.

[0082] The control unit 300 can acquire the surface image acquired by the image sensor unit 120 and measure a contrast ratio of the surface image of the object OB included in the focal areas FA1 and FA2. Specifically, the control unit 300 can measure contrast information of each area on the surface image of the object OB included in the focal areas FA1 and FA2, and can measure the contrast ratio of the surface image of the object OB included in the focal areas FA1 and FA2 using a difference in contrast information of each area.

[0083] In one embodiment, the control unit 300 may measure the contrast ratio using a difference between the lux value of the brightest part and the lux value of the darkest part of the surface image of the object OB included in the focal areas FA1 and FA2.

[0084] As the position of the lens unit 110 is changed, the contrast information of each area on the surface image of the object OB contained in the focal areas FA1 and FA2 changes, and the control unit 300 can measure the contrast ratio of the focal areas FA1 and FA2, which differ depending on the position of the lens unit 110.

[0085] Referring to Figures 3a to 4c, a control unit 300 according to one embodiment of the present invention can drive the driving unit 200 to move the lens unit 110 along a movement axis, and the control unit 300 can extract the contrast ratio of the focal areas FA1 and FA2 using images of the focal areas FA1 and FA2 obtained from the image sensor unit 120 while moving the lens unit 110.

[0086] As a result, the control unit 300 can obtain the contrast ratio relationship between the position of the lens unit 110 and the surface image contained in the focal areas FA1 and FA2, and thereby perform a contrast autofocus (contrast AF) operation as a method of deriving the position of the lens unit 110 where the contrast ratio is maximum.

[0087] Referring to Figures 2 and 5, the control unit 300 can measure the depth of the processing area G formed on the surface of the object OB by performing contrast autofocus on different focal areas FA1 and FA2, and a detailed description of this will be given in the method for measuring the depth of a processing area of ​​a scribing workpiece.

[0088] Referring to FIG. 1, an illumination unit 400 according to an embodiment of the present invention irradiates light onto a surface of an object OB where a processing area G is to be formed, and may include a light source unit 410 and a mirror unit 420.

[0089] The light source unit 410 may be composed of various devices that can be a light source, such as an LED or an incandescent lamp.

[0090] The mirror unit 420 can guide the light L generated from the light source unit 410 to move in the same direction as the optical axis of the lens unit 110. Specifically, a plurality of mirror units 420 may be provided, and the plurality of mirror units 420 may be arranged at a preset angle to each other, so that the light L generated from the light source unit 410 can be irradiated onto the surface of the object OB along the optical axis of the lens unit 110.

[0091] As a result, light L generated from the light source unit 410 is irradiated onto the surface of the target object OB along an optical axis perpendicular to the surface of the target object OB, so that no shadow is generated in the area where the processing area G is formed, and the control unit 300 can precisely measure the contrast information of each area of ​​the surface image of the target object OB contained in the focal areas FA1 and FA2.

[0092] Hereinafter, a method for measuring the depth of a processed region of a scribed workpiece according to an embodiment of the present invention and its effects will be described.

[0093] Figure 6 is a flow chart of a method for measuring the depth of a processing region of a scribing workpiece according to an embodiment of the present invention. Figure 7 is a flow chart of a method for detecting a first position of a lens portion according to an embodiment of the present invention. Figure 8 is a flow chart of a method for detecting a second position of a lens portion according to an embodiment of the present invention.

[0094] Referring to FIG. 6, in one embodiment of the present invention, a method for measuring the depth of a processing area of ​​a scribing workpiece (hereinafter referred to as a "method for measuring the depth of a processing area") may include step S100 of acquiring a surface image of an object having a processing area G formed thereon from an imaging unit having a lens unit, step S200 of detecting a first position of the lens unit that focuses on a first area spaced apart from the processing area G on the surface image, step S300 of detecting a second position of the lens unit that focuses on a second area on the surface image where the processing area G is located, and step S400 of measuring the depth of the processing area G using the first and second positions of the lens unit, and the first and second positions P1 and P2 of the lens unit 110 may be determined by a contrast ratio measured as the lens unit 110 moves.

[0095] In step S100 of acquiring a surface image of an object having a processing area G according to one embodiment of the present invention, the control unit 300 can divide the surface image of the object OB into pre-defined areas and acquire contrast information for each divided area.

[0096] The predetermined region may be set to a unit pixel, and the contrast information of each divided region may be a contrast value of each pixel, but is not limited thereto, and the predetermined region may be set as a group of a plurality of unit pixels, and the contrast information of each divided region may be at least one of an average value, a median value, a maximum value, and a minimum value of the contrast values ​​of the unit pixels constituting the group.

[0097] Hereinafter, in this specification, the "first region A1" may be interpreted as a region where the processing region G is not formed on the surface of the target object OB, and the "second region A2" may be interpreted as a region where the processing region G is located on the surface of the target object OB.

[0098] 2 to 3c and 7, step S200 of detecting a first position of the lens unit focused on a first region according to one embodiment of the present invention may include step S210 of setting a region of a surface image including both the first region and the second region as a first focal region, step S220 of performing a contrast autofocus operation for the first focal region, and step S230 of detecting the position of the lens unit when the contrast ratio of the first focal region is maximum as the first position.

[0099] Referring to Figure 2, in step S210 of setting a region of the surface image including both the first region and the second region as the first focal region, the control unit 300 can set a region of the surface image including both the region where the processing region G is located and the region where the processing region G is not located on the surface image of the object OB acquired from the imaging unit 100 as the first focal region FA1.

[0100] In one embodiment, the controller 300 may receive a control command from an external device and set the position and size of the first focal area FA1.

[0101] Specifically, the user can set a predetermined point on the surface image of the object OB obtained from the imaging unit 100 as the center C1 of the first focal area, and can set the shape and width of the first focal area FA1.

[0102] In one embodiment, the control unit 300 may set the position and size of the first focal area FA1 according to a preset algorithm.

[0103] The control unit 300 can set the first focal area FA1 such that the center C1 of the first focal area coincides with the center CL of the processing area according to a preset algorithm.

[0104] The control unit 300 can set the length W1 of the first focal area FA1 in the width direction of the processing area G (the upper direction in FIG. 2) according to a preset algorithm.

[0105] In one embodiment, the length W1 of the first focal area FA1 in the width direction of the processing area G is preferably 1.1 to 10 times the width W0 of the processing area G, more preferably 1.3 to 3 times, and even more preferably 1.5 to 2 times.

[0106] The control unit 300 can set the first focal region FA1 such that the size of the first region A1 included in the first focal region FA1 is relatively larger than the size of the second region A2 included in the first focal region FA1.

[0107] In one embodiment, the size of the first region A1 contained in the first focal region FA1 is preferably 1.1 to 10 times the size of the second region A2 contained in the first focal region FA1, more preferably 1.3 to 3 times, and even more preferably 1.5 to 2 times.

[0108] Referring to Figures 3a to 3c, in step S220 of performing a contrast autofocus operation for a first focal area according to one embodiment of the present invention, the control unit 300 can drive the driving unit 200 to move the lens unit along a preset movement axis, and the control unit 300 can measure the contrast ratio of the first focal area FA1 obtained by moving the lens unit 110.

[0109] Specifically, as the lens unit 110 moves, the control unit 300 can acquire images of the first focal area FA1 having different contrast ratios from the image sensor unit 120, and thereby the control unit 300 can extract contrast ratio information of the first focal area FA1 according to the position of the lens unit 110.

[0110] Referring to FIG. 3b, in step S230 of detecting the position of the lens unit when the contrast ratio of the first focal region is maximum as the first position according to one embodiment of the present invention, the control unit 300 can detect the position of the lens unit 110 when the contrast ratio of the first focal region FA1 is maximum as the first position P1 using contrast ratio information of the first focal region FA1 according to the extracted position of the lens unit 110.

[0111] As an alternative embodiment, the control unit 300 may detect, as the first position P1, a position of the lens unit 110 at which the contrast ratio of the first focal area FA1 increases or decreases as the lens unit 110 moves.

[0112] In one embodiment, after the first position P1 of the lens unit 110 is set as a reference point, a step S300 can be performed to detect a second position of the lens unit where the focus is on the second region.

[0113] 2 to 4c and 8, step S300 of detecting a second position of the lens unit focused on a second region according to one embodiment of the present invention may include step S310 of acquiring position information of a processing region G, step S320 of setting a region of the surface image as a second focal region based on the acquired position information of the processing region G, step S330 of performing a contrast autofocus operation for the second focal region, and step S340 of detecting the position of the lens unit when the contrast ratio of the second focal region is maximum as the second position, where the second focal region may be included in the second region.

[0114] In step S310 of acquiring position information of the processing area G according to an embodiment of the present invention, the control unit 300 can acquire information regarding the area where the processing area G is located on the surface image of the object OB acquired from the imaging unit 100.

[0115] Referring to Figure 2, in step S320 of setting a region of the surface image as a second focal region based on the position information of the processing area G acquired according to one embodiment of the present invention, the control unit 300 can set a region of the surface image included in the area where the processing area G is located on the surface image of the object OB acquired from the imaging unit 100 as the second focal region FA2.

[0116] In one embodiment, the controller 300 may receive a control command from an external device and set the position and size of the second focal area FA2.

[0117] Specifically, the user can set a predetermined point on the surface image of the object OB obtained from the imaging unit 100 as the center C2 of the second focal area, and can set the shape and size of the second focal area FA2.

[0118] In one embodiment, the control unit 300 may set the position and size of the second focal area FA2 according to a preset algorithm.

[0119] The control unit 300 can set the second focal area FA2 so that the center C2 of the second focal area coincides with the center CL of the processing area G according to a preset algorithm.

[0120] Referring to FIG. 2, the control unit 300 can set the second focal region FA2 such that the center C2 of the second focal region coincides with the center C1 of the first focal region.

[0121] The control unit 300 can set the length W2 of the second focal area FA2 in the width direction (upper direction in FIG. 2) of the processing area G according to a preset algorithm.

[0122] In one embodiment, the length W2 of the second focal area FA2 in the width direction of the processing area G is preferably 0.3 to 1 times the width W0 of the processing area G, and more preferably 0.5 to 1 times.

[0123] As an optional embodiment, the control unit 300 can set the length W2 of the second focal region FA2 in the width direction of the processing area G by using the length W1 of the first focal region FA1 in the width direction of the processing area G. Specifically, the length W1 of the first focal region FA1 in the width direction of the processing area G may be 1.2 times or more and 10 times or less, preferably 1.5 times or more and 3 times or less, and more preferably 2 times or more and 3 times or less, of the length W2 of the second focal region FA2 in the width direction of the processing area G.

[0124] Referring to Figures 4a to 4c, in step S330 of performing a contrast autofocus operation for a second focal area according to one embodiment of the present invention, the control unit 300 can drive the driving unit 200 to move the lens unit 100 along a preset movement axis, and the control unit 300 can measure the contrast ratio of the second focal area FA2 obtained by moving the lens unit 100.

[0125] Specifically, as the lens unit 110 moves, the control unit 300 can acquire images of the second focal area FA2 having different contrast ratios from the image sensor unit 120, and thereby the control unit 300 can extract contrast ratio information of the second focal area FA2 according to the position of the lens unit 110.

[0126] Referring to FIG. 4b, in step S340 of detecting the position of the lens unit when the contrast ratio of the first focal region is maximum as the second position according to one embodiment of the present invention, the control unit 300 can detect the position of the lens unit 110 when the contrast ratio of the first focal region FA1 is maximum as the second position P2 using contrast ratio information of the second focal region FA2 corresponding to the extracted position of the lens unit 110.

[0127] As an alternative embodiment, the control unit 300 may detect, as the second position P2, a position of the lens unit 110 at which the contrast ratio of the second focal area FA2 increases or decreases as the lens unit 110 moves.

[0128] Referring to FIG. 5, in step S400 of measuring the depth of the processing area G using the first and second positions of the lens unit, the control unit 300 can measure the depth of the processing area G using the position difference D between the first position P1 and the second position P2 of the lens unit 110.

[0129] Specifically, the control unit 300 can measure the depth of the processing area G formed on the surface of the object OB using the distance D between the first position P1 and the second position P2 in a direction perpendicular to the surface of the object OB.

[0130] This has the effect of making it possible to precisely measure the depth of the processing area G by measuring the contrast ratio of the surface image with different settings of the focal areas FA1 and FA2, without the need to cut the object OB and examine the cross section of the processing area G with a separate microscope.

[0131] The concept of the present invention should not be limited to the embodiments described above, and all scopes equivalent to or modified equivalently to the scope of the claims below, as well as the scope of the concept of the present invention, shall be considered to belong to the scope of the present invention. [Explanation of symbols]

[0132] 1: Machining area measuring device OB: Workpiece G: Processing area F: Film AD: Adhesive PN: Panel FA1: 1st focal area FA2: 2nd focal area CL: Center line L: Light source 100: Imaging section 110: Image sensor section 120: Lens section 200: Drive section 300: Control unit 400: Lighting unit 410: Light source section 420: Mirror section

Claims

1. acquiring a surface image of a target object having a processed surface from an imaging unit provided with a lens unit; detecting a first position of the lens portion at which a first area on the surface image is focused, the first area being away from a processing area; detecting a second position of the lens portion at which a second area on the surface image where the processing area is located is focused; measuring a depth of the processed region using the first position and the second position of the lens portion; The method for measuring a depth of a processed region of a scribed object, wherein the first and second positions of the lens unit are determined according to a contrast ratio measured by moving the lens unit.

2. The step of detecting a first position of the lens portion includes: The method for measuring the depth of a processing region of a scribing workpiece according to claim 1, further comprising the step of setting a region of the surface image including both the first region and the second region as a first focal region.

3. The step of detecting a first position of the lens portion includes: The method for measuring the depth of a processing area of ​​a scribing workpiece according to claim 2, characterized in that a contrast autofocus operation is performed for the first focal area, and the position of the lens part when the contrast ratio of the first focal area is maximum is detected as the first position.

4. The method for measuring the depth of a processed region of a scribed workpiece according to claim 3, wherein the center of the first focal region coincides with the center of the processed region.

5. The step of detecting a second position of the lens portion includes: acquiring position information of the processing area; and setting a region of the surface image as a second focal region based on the acquired position information of the processing region; The method for measuring the depth of a processed region of a scribed workpiece according to claim 2 , wherein the second focal region is included in the second region.

6. The step of detecting a second position of the lens portion includes: The method for measuring the depth of a processing area of ​​a scribing workpiece according to claim 5, characterized in that a contrast autofocus operation is performed for the second focal area, and the position of the lens part when the contrast ratio of the second focal area is maximum is detected as the second position.

7. The method for measuring the depth of a processed region of a scribed workpiece according to claim 5, wherein a center of the first focal region and a center of the second focal region are aligned with each other.

8. 2. The method for measuring the depth of a processed area of ​​a scribed object according to claim 1, wherein an angle between a normal vector of the surface of the object passing through a center of the processed area and the optical axis of the lens portion is 5° or less.

9. The method of claim 1 , wherein the lens unit is movable along a preset movement axis, the movement axis being perpendicular to a surface of the object.

10. The step of measuring the depth of the processed region includes: The method for measuring the depth of a processed region of a scribed workpiece according to claim 6, wherein the depth of the processed region is calculated using a difference between the first position and the second position of the lens portion.

11. an imaging unit for acquiring a surface image of a target object having a processed surface; a lens unit disposed between the imaging unit and the target object and movable in one direction perpendicular to a surface of the target object; a control unit for controlling movement of the lens unit, The control unit is 13. An apparatus for measuring the depth of a processed region of a scribed object, comprising: a lens unit for moving in one direction, the lens unit being capable of measuring a contrast ratio of the surface image acquired by the movement of the lens unit in the one direction.

12. The control unit is The position of the lens unit focused on a first area separated from a processing area on the surface of the target object and the position of the lens unit focused on a second area in which the processing area is located can be detected; The device for measuring the depth of a processing area of ​​a scribing workpiece according to claim 11, characterized in that the depth of the processing area is measured using the position of the lens portion focused on the first area and the position of the lens portion focused on the second area in which the processing area is located.

Images