High-speed automatic film foreign body detection device

Abstract

The present invention includes a stage on which a sample is placed, a plurality of side light units arranged on an upper side of the stage and irradiating side light toward the sample when the low-magnification optical module is operated, a low-magnification optical module installed on the upper side of the stage and imaging the sample to generate a low-magnification image so that foreign objects can be detected from the sample using light scattering of the foreign objects caused by the side light irradiated from the side light unit, a high-magnification optical module installed on one side of the stage and connected to a high-magnification driving unit and driven in x-axis, y-axis and z-axis directions, imaging the sample to generate a high-magnification image, and a user device that controls the operation of the low-magnification optical module and the high-magnification optical module and receives the low-magnification image and the high-magnification image for storage, playback and analysis.

Description

[Technical field]

[0001] The present invention relates to an apparatus that can detect foreign matter present in a film and identify the shape, color, size, optical characteristic values, etc. of the foreign matter, and can determine the layer and depth in which the foreign matter exists within a sample and the height of the foreign matter to determine the quality and usability of the product. [Background technology]

[0002] In cutting-edge industries involving highly precise manufacturing processes at the nano level, even slight environmental conditions can have a significant impact on product quality, so there is a trend toward stricter standards of cleanliness required in cleanrooms.

[0003] Displays are used in mobile phones, tablet PCs, monitors, home appliances, automotive electronic devices, etc. and are made of OCA film, polarizing film, glass, etc. If foreign objects of a certain size or larger are present in such displays, they can cause pixel defects or deterioration of image quality.

[0004] In the conventional optical device, a plurality of objective lenses having different magnifications are selected by rotating a turntable to generate low-magnification and high-magnification images, respectively. Therefore, in the conventional optical device, the general location of the foreign object in the entire image is determined using the low-magnification objective lens, and then the area where the foreign object is detected is searched again using the high-magnification objective lens for detailed observation. In the conventional optical device, the low-magnification objective lens must be switched to the high-magnification objective lens for detailed observation, and the area where the foreign object of the sample is detected must be searched for and the high-magnification objective lens must be aligned with the area where the foreign object of the sample is detected, which is time-consuming and cumbersome.

[0005] Korean Patent Publication No. 10-2020-0052157 (published on May 14, 2020) discloses a digital microscope that includes a stage on which a sample is placed, a low-magnification optical module that images the sample to generate a low-magnification image, a high-magnification optical module located on the opposite side of the low-magnification optical module that images the sample to generate a high-magnification image, a driving module that moves the high-magnification optical module, and a user device on which the low-magnification image and high-magnification image are reproduced, and in which the imaging area of ​​the high-magnification optical module is changed by driving the driving module.

[0006] However, the above-mentioned conventional technology has a problem that it is difficult to detect small foreign objects in a low magnification image because it uses direct light, it takes a long time to detect, and it is not possible to grasp the layer and depth where the foreign object exists in the sample, the height of the foreign object, etc. That is, a multi-layered sample such as an OCA film used in a display product is composed of a base layer and a protective layer attached to both sides of the base layer. If the base layer contains foreign objects, the product is defective. However, since the protective layer is removed when used later, the product can be used as a normal product even if foreign objects exist in the protective layer. However, in the above-mentioned conventional technology, even if foreign objects are detected with a low magnification optical module, it is not possible to confirm the layer and depth where the foreign object exists in the sample with a high magnification optical module. Therefore, after removing the outer protective layer, the remaining sample must be observed with the optical module again to confirm which layer the foreign object exists in. However, in this process, the sample is destroyed or damaged, resulting in a loss due to the inspection, and not only is the inspection itself impossible during a full inspection, but when an operator removes the protective layer, foreign objects may adhere from the operator or equipment and become contaminated, making it difficult to accurately determine the depth where the foreign object exists in the sample and the height of the sample itself. Therefore, if a foreign substance is detected in the sample, the entire sample must be discarded. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-2020-0052157 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a high-speed automatic film foreign body detection device which can easily detect foreign bodies contained in a sample using a light scattering image captured by a low-magnification optical module, can identify the shape, color, size and optical characteristic values ​​of the foreign body by moving a high-magnification optical module to the foreign body coordinate area of ​​the sample, can quickly determine whether the product is usable by identifying the layer and depth in which the foreign body exists and the height of the foreign body without destroying or damaging the sample, and can also identify the type of foreign body by connecting to a foreign body analyzer. [Means for solving the problem]

[0009] The present invention provides an automatic high-speed foreign substance detection device for a film, comprising: a stage on which a sample is placed; side light units arranged on an upper side of the stage and irradiating side light toward the sample when the low-magnification optical module is operated; a low-magnification optical module arranged on the upper side of the stage and imaging a sample to generate a low-magnification image by using light scattering of the foreign substance caused by the side light irradiated from the side light unit so that foreign substances can be detected from the sample; a high-magnification optical module arranged on one side of the stage and connected to a high-magnification driving unit and driven in x-, y- and z-axis directions to image the sample with direct light to generate a high-magnification image; and a user device for controlling the operation of the low-magnification optical module and the high-magnification optical module and for receiving the low-magnification image and the high-magnification image for storage, playback and analysis. Effect of the Invention

[0010] According to the present invention, foreign matter contained in a sample can be easily detected from a light scattering image captured by a low magnification optical module, and the shape, color, size, and optical characteristic values ​​of the foreign matter can be confirmed by moving the high magnification optical module to the foreign matter coordinate area of ​​the sample. This makes it possible to quickly determine whether the product is usable by identifying the layer and depth in which the foreign matter exists in the sample and the height of the foreign matter without destroying or damaging the sample, and also makes it possible to identify the type of foreign matter by connecting a foreign matter analyzer. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of an apparatus according to the present invention. [Diagram 2] FIG. 2 is a plan view showing the arrangement of a side light unit according to the present invention; [Figure 3a] FIG. 2 shows a region of interest of a sample according to the present invention. [Figure 3b] FIG. 3b is a cross-sectional view of the sample of FIG. 3a. [Figure 4a] 13A and 13B are diagrams illustrating a process in which a high magnification optical module moves to a foreign object coordinate area after a reference plane is determined in an adjacent coordinate area according to the present invention. [Figure 4b] 13 is a diagram showing a process in which a high magnification optical module determines the depth and height of a foreign object while descending in a foreign object coordinate area; [Figure 5a] 1 is a graph showing a distribution of a maximum layer detectable index (LDImax) according to a depth (t) from a top surface of a sample containing a foreign substance having a property of reflecting light according to the present invention. [Figure 5b] 1 is a graph showing a distribution of a layer detectable minimum index (LDImin) according to a depth (t) from a top surface of a sample containing a foreign substance having a property of absorbing light in accordance with the present invention; [Figure 6] 11A to 11C are diagrams illustrating a process of determining a reference plane for each foreign particle when a sample is in a bent state having a bend according to the present invention. [Figure 7a] 4 is a flowchart showing a process for detecting and analyzing foreign matter in a sample according to an embodiment of the present invention. [Figure 7b]4 is a flowchart showing a process for detecting and analyzing foreign matter in a sample according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Referring to FIG. 1, the high-speed automatic film foreign body detection device of the present invention includes a stage 100, a side light unit 200, a low magnification optical module 300, a high magnification optical module 400, and a user device 500, and may further include a foreign body type analyzer (not shown).

[0013] The stage 100 provides a mounting surface on which the sample 10 made of a film can be mounted, and is disposed below the side light unit 200. The sample 10 may be a transparent or semi-transparent single-layer film or a multi-layer film. For example, the stage 100 may have a shape such as a hollow hexahedron or cylinder, and may have a mounting groove on the upper surface in which the sample 10 is mounted, and a through hole may be formed in the mounting groove.

[0014] 2, a plurality of side light units 200 are arranged on the upper side of the stage 100 and irradiate side light toward the sample 10 when the low magnification optical module 300 is operated. The side light units 200 irradiate side light toward the sample 10 placed on the stage 100, and the low magnification optical module 300 detects light reflected by foreign matter to detect foreign matter contained in the sample. The side light units 200 may be LEDs, lasers, etc.

[0015] The side light unit 200 preferably has a light irradiation angle of 5 degrees to 45 degrees with respect to the sample 10. When the side light irradiated from the side light unit 200 is reflected by a foreign object, light scattering occurs, in which the light spreads, and the detection size that the image sensor of the low magnification optical module 300 can receive is increased, thereby increasing the detection power. Therefore, foreign objects can be easily and quickly detected and confirmed from the low magnification image captured by the low magnification optical module 300. Foreign objects smaller than the size detectable by the low magnification optical module 300 or foreign objects that do not reflect light well can also be detected.

[0016] 3a and 3b, a sample 10 such as a multi-layered OCA film includes a base layer 11 and an upper protective layer 12 and a lower protective layer 13 respectively attached to both sides of the base layer 11. If the lower protective layer 13 is provided with an area larger than the base layer 11, it is necessary to inspect only the area of ​​interest where the base layer 11 is present, where foreign matter needs to be detected. When a side light is irradiated toward the sample 10 using the side light unit 200 and a low magnification image is captured by the low magnification optical module 300, the base layer 11 is formed protruding above the lower protective layer 13 and reflects light, and the boundary line L between the base layer 11 and the lower protective layer 13 is displayed as a colored line in the low magnification image. Therefore, the user device 500 can cut out a region of interest R from the low magnification image along the boundary line L displayed as a colored line, and detect and confirm foreign matter only in the region of interest R.

[0017] The low magnification optical module 300 is installed above the stage 100, but at a higher position than the high magnification optical module 400. For example, the low magnification optical module 300 may be supported and installed on a frame (not shown), and a hole may be formed through the frame to enable imaging of the sample 10 placed on the stage 100 below. The low magnification optical module 300 includes an image sensor, and generates a low magnification image by imaging the sample 10 so that foreign matter can be detected from the sample 10 by using light scattering of the foreign matter caused by side light irradiated from the side light unit 200. The optical axis of the low magnification optical module 300 is arranged based on the z-axis. When the low magnification optical module 300 is operated to perform imaging, the high magnification optical module 400 waits outside the field of view of the low magnification optical module 300, i.e., on one side of the stage 100.

[0018] The low magnification optical module 300 has a large angle of view and a wide imaging area, and can generate a low magnification image of the entire area of ​​the sample 10. The low magnification driving unit 310 is connected and driven and controlled in the vertical direction in the z-axis direction to adjust the imaging area according to the sample 10 placed on the stage 100. The low magnification driving unit 310 may be a lead screw, a ball screw, a linear guide, a belt, or the like operated by a motor. The imaging area of ​​the low magnification optical module 300 may be 200 mm wide x 150 mm long. The low magnification image captured by the low magnification optical module 300 includes light scattering that occurs when the side light irradiated from the side light unit 200 is reflected by a foreign object. This increases the detection size that the image sensor of the low magnification optical module 300 can accept, thereby increasing the detection power, and can easily and quickly detect and confirm foreign objects, and can detect foreign objects smaller than the size that the low magnification optical module 300 can detect. For example, by using light scattering as described above, it is possible to detect small particles that are about 1 / 3 the size that the low magnification optical module 300 can detect. If multiple foreign objects are present in the sample 10, the user device 500 can determine the quality of the sample by calculating the distance between the foreign objects based on the low magnification image transferred from the low magnification optical module 300. For example, even if multiple foreign objects having a size below a reference value are detected in the sample 10, they can be determined to be defective if the distance between the foreign objects is close to each other. However, since the foreign objects are displayed as bright dots in the low magnification image captured by the low magnification optical module 300, the actual shape, color, size, etc. of the foreign objects cannot be known.

[0019] The high magnification optical module 400 is installed on one side of the stage 100, and an image sensor is installed to capture the sample 10 to generate a high magnification image. A high magnification driving unit 410 is connected and driven in the x-axis, y-axis, and z-axis directions. For example, a plurality of high magnification driving units 410 may be installed and driven individually in the x-axis, y-axis, and z-axis directions. The high magnification driving unit 410 may use various driving devices so that the high magnification optical module 400 can move in the x-axis, y-axis, and z-axis directions. For example, the high magnification driving unit 410 may use a lead screw, a ball screw, a linear guide, a belt, etc. operated by a motor. The above-mentioned x-axis, y-axis, and z-axis may be each axis in the left-right direction, the front-back direction, and the up-down direction constituting an optical module coordinate system formed based on the space of the mounting surface on the stage 100. When the high-magnification driving unit 410 moves the high-magnification optical module 400 based on the x-axis or y-axis, the high-magnification optical module 400 can move in parallel with the sample placement surface of the stage 100 without changing its height, and when the high-magnification driving unit 410 moves the high-magnification optical module 400 based on the z-axis, the focal length relative to the sample can be changed as the height of the high-magnification optical module 400 changes.

[0020] The high magnification optical module 400 is provided with a direct light unit 420 at its bottom for irradiating direct light toward the sample 10. When the high magnification optical module 400 captures a high magnification image, the direct light unit 420 can irradiate direct light, side light, or light at various angles. The optical axis of the high magnification optical module 400 is arranged based on the z-axis. In the present invention, the magnification ratio between the low magnification optical module 300 and the high magnification optical module 400 is preferably 1,000:1 or more. The high magnification optical module 400 is moved in the x-axis and y-axis directions by the high magnification driving unit 410, and can be moved to a foreign object coordinate area where a foreign object is detected in the low magnification image and captured to check the shape, color, size, optical characteristic value, etc. of the foreign object in detail from the captured high magnification image. It is also possible to quickly determine whether or not there is a quality abnormality in the product by checking the layer and depth where the foreign object exists in the sample and the height of the foreign object. The high magnification optical module 400 has a small angle of view and a narrow imaging area, and can generate a high magnification image of a part of a sample, and can adjust the distance to the sample by controlling the driving in the z-axis direction of the high magnification driving unit 410 connected thereto. As an example, the imaging area of ​​the high magnification optical module 400 can be 2 mm wide x 1 mm long.

[0021] The user device 500 controls the operation of the low magnification optical module 300 and the high magnification optical module 400, receives, stores, plays, and analyzes low magnification images and high magnification images, extracts optical characteristic values ​​from the high magnification images, and compares and judges them. The user device 500 may be an electronic device such as a computer, a notebook computer, a smartphone, a tablet PC, or a PDA that includes a display screen and a communication module. A dedicated program that can compare and analyze low magnification images and high magnification images is installed in the user device 500. The optical characteristic value can be any one selected from RGB values, YUV values, HSB values, and Lab values. RGB values ​​are a method of expressing an image by mixing red R, green G, and blue B. An image is made up of a number of very small squares called pixels, and each pixel is made up of a combination of red, green, and blue, and each of red, green, and blue can be expressed as a number with 256 levels of color from 0 to 255. For example, RGB(255,0,0) can be expressed as red, and RGB(255,100,0) can be expressed as red mixed with green. YUV values ​​are a method of expressing color using three types of information: luminance signal Y, chrominance between luminance signal and blue component U, and chrominance between luminance signal and red component V, and RGB values ​​and YUV values ​​can be converted between each other using a set formula. HSB values ​​are values ​​representing hue H, saturation S, and brightness B, and are a method of expressing color information mainly used in programs such as Photoshop (registered trademark). Hue H has a range of 0° to 360°, and saturation S represents the degree of darkness when the darkest state of a particular color is 100%, and a saturation value of 0% represents an achromatic color of the same brightness. Brightness B represents the degree of brightness when white is 100% and black is 0%. Lab values ​​are a color system re-established by the international standard color measurement equipment called CIE (Commission Internationale d'Eclairage). Even for the same color, there can be subtle or significant differences between the color seen on one's monitor and the color seen on another monitor. This color model was developed to compensate for such differences.It is generally written as L*a*b*, where the L component refers to luminosity, the a component refers to the relationship between green and red, and if it goes towards negative numbers it becomes greener and if it goes towards positive numbers it becomes redder. The b component refers to the relationship between blue and yellow, and if it goes towards negative numbers it becomes bluer and if it goes towards positive numbers it becomes yellower.

[0022] When the optical characteristic values ​​are used as RGB values, the maximum layer detectable index LDI is as follows: max (Layer Detectable Maximum Index) can be calculated and used.

[0023] LDI max =R max ×G max ×B max R max : The maximum R component value of the pixels in the high magnification image capture area G max : The maximum G component value of the pixels in the high magnification image capture area B max :The maximum value of the B component of the pixels in the high magnification image capture area

[0024] That is, there are a number of pixels in the high magnification image capturing area. For example, the horizontal and vertical pixel values ​​in the high magnification image capturing area are 500×500 pixels, and the optical characteristic value is extracted for each pixel, among which R max , G max , B max If we search for and multiply it, we get the LDI. max is derived.

[0025] Generally, light irradiated from a light source toward the sample 10 is reflected or scattered by foreign matter, but some foreign matter such as carbon black has the property of absorbing light. In such a case, the optical characteristic value of the foreign matter appears relatively low in the high magnification image of the sample captured by the high magnification optical module 400. Therefore, when the optical characteristic value is used in RGB, the minimum layer detectable index LDI is as follows: min(Layer Detectable Minimum Index) can be calculated and used.

[0026] LDI min =R min ×G min ×B min R min : The minimum R component value of the pixels in the high magnification image capture area G min : The minimum G component value of the pixels in the high magnification image capture area B min : The minimum value of the B component of the pixels in the high magnification image capture area

[0027] That is, there are a number of pixels in the high magnification image capturing area. For example, the horizontal and vertical pixel values ​​in the high magnification image capturing area are 500×500 pixels, and the optical characteristic value is extracted for each pixel, among which R min , G min , B min If we search for and multiply it, we get the LDI. min is derived.

[0028] In this way, the LDI is converted to a significantly larger or smaller number by multiplying the maximum or minimum values ​​of the R, G, and B components. max or LDI min By using LDI, the optical characteristic values ​​of the area where foreign objects exist and the area where foreign objects do not exist are significantly different, and the accuracy of detecting the layer and depth where foreign objects exist, the height of foreign objects, etc. is increased, and even if some of the pixels in the high magnification image area have RGB value errors, some of the image sensors have defective pixels, or noise occurs, the layer and depth where foreign objects exist, and the height of foreign objects can be determined without error. max and LDI min In the above description, only RGB values ​​are applied to deriving the above, but YUV values, HSB values, and Lab values ​​can also be applied to the present invention by multiplying the maximum or minimum value of each component value constituting the optical characteristic value extracted for each pixel in the imaging area of ​​the high magnification image.

[0029] The user device 500 may include a reference value storage unit 510, a region of interest extraction unit 520, a foreign object detection unit 530, a coordinate determination unit 540, an optical module control unit 550, an optical characteristic value extraction unit 560, a reference plane determination unit 570, a foreign object analysis unit 580, and a judgment unit 590.

[0030] The reference value storage unit 510 stores a range of reference values ​​of the upper surface of the sample for optical characteristic values ​​extracted from a high-magnification image previously captured by the high-magnification optical module 400 with respect to the upper surface of the sample, and a range of reference values ​​of foreign matter for optical characteristic values ​​extracted from a high-magnification image captured by the high-magnification optical module 400 of a foreign matter-containing region after the sample 10 is previously included in the sample. More specifically, after the sample 10 without foreign matter is placed on the stage 100, the high-magnification optical module 400 is manually moved vertically above the sample 10, and the optical characteristic value of the upper surface of the sample 10 is extracted when the focus is on the upper surface of the sample. In order to increase accuracy, optical characteristic values ​​are repeatedly extracted for multiple points on the upper surface of the sample. At this time, the horizontal and vertical pixel values ​​of the high-magnification image captured by the high-magnification optical module 400 are predetermined. For example, the horizontal and vertical pixel values ​​of the high-magnification image are 500×500 pixels, and optical characteristic values ​​are extracted for each pixel, and the LDI is performed. max or LDI min can be calculated and determined as the reference value of the upper end surface of the sample. In addition, by repeatedly performing this for a plurality of points on the upper end surface of the sample, the optical characteristic values ​​for each imaging region on the upper end surface of the sample are derived, and the range of the reference value of the upper end surface of the sample is determined. For example, the range of the reference value of the upper end surface of the sample can be determined by the above-mentioned LDI max or LDI min The reference value can be stored in the reference value storage unit 510 in the range.

[0031] A specific foreign particle having a certain size is artificially included in the sample 10, and the sample 10 containing the foreign particle is placed on the stage 100. The high magnification optical module 400 is then manually moved vertically over the foreign particle coordinate area, and the optical characteristic value of the foreign particle is extracted when the foreign particle is focused on. At this time, the horizontal and vertical pixel values ​​of the high magnification image captured by the high magnification optical module 400 are predetermined. For example, the horizontal and vertical pixel values ​​of the high magnification image are 500×500 pixels, and the optical characteristic value is extracted for each pixel, and the LDI max or LDI min can be calculated and determined as the foreign particle reference value. In addition, by repeatedly extracting the optical characteristic values ​​by including foreign particles at several depths in the sample 10, the optical characteristic values ​​for the foreign particle coordinate region can be derived and the range of the foreign particle reference value can be determined. For example, the range of the foreign particle reference value can be determined by the above-mentioned LDI max or LDI min The reference value can be stored in the reference value storage unit 510 in the range.

[0032] The region of interest extraction unit 520 extracts the region of interest R by cutting out the boundary line L displayed as a colored line by side light from the low-magnification image captured by the low-magnification optical module 300. Recently, the detection region of multilayer films for display products such as smartphones has been expanded to the film edge due to the reduction in the bezel of the product. Therefore, when the side light is irradiated toward the sample 10 using the side light unit 200 and the low-magnification image is captured by the low-magnification optical module 300, the boundary line L between the base layer 11 and the lower protective layer 13 is displayed as a colored line in the low-magnification image. Therefore, the region of interest extraction unit 520 cuts out the region of interest R along the boundary line L displayed as a colored line in the low-magnification image, and can detect and confirm foreign matter only in the region of interest R.

[0033] The foreign object detector 530 detects foreign objects from the low-magnification image captured by the low-magnification optical module 300 of the sample 10 by using light scattering of the foreign object caused by side light irradiated from the side light unit 200. In this case, the foreign object detector 530 can detect foreign objects in the region of interest R. The coordinate determiner 540 derives a foreign object coordinate area in which a foreign object is detected from the low-magnification image, matches the imaging area of ​​the high-magnification optical module 400 with the foreign object coordinate area, and determines an adjacent coordinate area adjacent to the foreign object coordinate area that is free of foreign objects. As an example, the coordinate determiner 540 derives a foreign object coordinate area on the stage 100 from a wide low-magnification image, matches a narrow imaging area of ​​the high-magnification optical module 400 with the foreign object coordinate area, and determines an adjacent coordinate area free of foreign objects in the area adjacent to the foreign object coordinate area. Then, the optical module controller 550 transmits a control signal to the high-magnification drive unit 410 to move the high-magnification optical module 400 to the adjacent coordinate area.

[0034] The optical module control unit 550 controls the operation of the low magnification optical module 300 and the high magnification optical module 400, and transmits a control signal to the low magnification driving unit 310 to control the low magnification optical module 300 to move up and down, or transmits a control signal to the high magnification driving unit 410 to control the high magnification optical module 400 in the x-axis and y-axis directions to move to a foreign object coordinate area or an adjacent coordinate area adjacent to the foreign object coordinate area where there is no foreign object, thereby controlling the low magnification optical module 300 and the high magnification optical module 400 to capture an image. The optical module control unit 550 controls the high magnification driving unit 410 in the adjacent coordinate area so that the high magnification optical module 400 moves in the z-axis direction by a certain numerical amount, for example, 0.1 μm, to continuously capture high magnification images. When the reference plane S is determined by the reference plane determination unit 570, the high magnification driving unit 410 is controlled so that the high magnification optical module 400 moves horizontally from the adjacent coordinate area to the foreign object coordinate area along the reference plane S, and then the high magnification driving unit 410 is controlled in the foreign object coordinate area so that the high magnification optical module 400 descends in the z-axis direction from the reference plane S by a certain numerical amount, for example, 0.1 μm, to continuously capture high magnification images.

[0035] The optical characteristic value extraction unit 560 extracts optical characteristic values ​​from the high magnification image captured and received by the high magnification optical module 400. At this time, the optical characteristic value extraction unit 560 extracts the LDI from the extracted optical characteristic values. max or LDI min can be calculated and used.

[0036] The reference plane determination unit 570 compares in real time the optical characteristic values ​​extracted by the optical characteristic value extraction unit 560 from the high magnification images continuously captured and transferred by the high magnification optical module 400 in adjacent coordinate areas adjacent to the foreign object coordinate area with the range of the reference value of the upper end surface of the sample stored in the reference value storage unit 510, and determines the position of the high magnification optical module 400 when the high magnification image from which the optical characteristic values ​​included in the range of the reference value of the upper end surface of the sample are extracted as the reference plane S. For example, the LDI extracted and calculated from the high magnification image by the optical characteristic value extraction unit 560 may be calculated as the reference plane S. max or LDI min is included in the range of the reference value of the sample upper surface, the height of the lower end of the high magnification optical module 400 is determined as the reference surface S. Referring to FIG. 4a, the reference surface S is the position where the high magnification optical module 400 is focused on the upper surface of the sample, and the distance between the reference surface S and the upper surface of the sample is defined as the reference distance . This is because the high magnification optical module 400 cannot automatically focus on the upper surface of the sample, so the range of the reference value of the sample upper surface for the optical characteristic value of the upper surface of the sample is extracted and stored in advance, and when the reference surface S is determined for inspecting the sample 10, the optical characteristic value extracted from the high magnification image captured in the adjacent coordinate area is compared with the range of the reference value of the sample upper surface to determine the reference surface S.

[0037] After the reference plane S is determined by the reference plane determination unit 570, the optical module control unit 550 controls the high magnification driving unit 410 to move the high magnification optical module 400 horizontally from the adjacent coordinate area to the foreign object coordinate area along the reference plane S as shown in FIG. 4b. The foreign object analysis unit 580 then compares in real time the optical characteristic values ​​extracted by the optical characteristic value extraction unit 560 from the high magnification images that the high magnification optical module 400 continuously captures and transfers while maintaining the focal length over the entire thickness of the sample 10 as it descends in the z-axis direction by a certain numerical value, for example, 0.1 μm, in the foreign object coordinate area including the foreign object F, with the range of the foreign object reference value stored in the reference value storage unit 510. Then, by calculating the vertical distance descended from the reference plane S of the high magnification optical module 400 when capturing the high magnification image from which the optical characteristic values ​​included in the range of the foreign object reference value are extracted, this is equal to the depth at which the foreign object exists from the top surface of the sample, and therefore the foreign object existence depth d in the sample can be confirmed. For example, the LDI extracted and calculated by the optical characteristic value extracting unit 560 from the high magnification image is max or LDI min is within the range of the foreign matter reference value, the vertical distance that the high magnification optical module 400 descends from the reference surface S can be calculated to confirm the foreign matter presence depth d. At this time, it is preferable that the optical module control unit 550 controls the high magnification driving unit 410 so that the high magnification optical module 400 is lowered to perform imaging over the entire thickness of the sample 10.

[0038] The foreign matter F contained in the sample 10 has a height, and when optical characteristic values ​​are extracted from a plurality of high magnification images captured in a range corresponding to the height h of the foreign matter, all of the optical characteristic values ​​may be included in the range of the foreign matter reference value. Therefore, the foreign matter analyzer 580 may determine the height h of the foreign matter F by calculating the vertical distance between the start position of the high magnification optical module 400 descending, where the optical characteristic values ​​extracted from the high magnification images captured continuously while the high magnification optical module 400 descends in the foreign matter coordinate area, where the optical characteristic values ​​begin to correspond to the range of the foreign matter reference value, and the end position of the high magnification optical module 400 descending, where the optical characteristic values ​​finally correspond to the range of the foreign matter reference value, and thus may determine the depth of the foreign matter F in the sample 10. For example, if the start position is 4 μm from the reference plane S and the end position is 9 μm from the reference plane S, the height h of the foreign matter F may be determined to be 5 μm.

[0039] LDI extracted and calculated from multiple high magnification images taken in the range corresponding to the height h of the foreign object F max The distribution of LDI can be shown as in Figure 5a. min The distribution of LDI can be shown in FIG. 5b. FIG. 5a shows the distribution of LDI as a function of depth t from the top surface of a sample 10 including a foreign object having a property of reflecting light according to the present invention. max FIG. 5b is a graph showing a distribution of LDI according to the present invention, which is a function of the depth t from the top surface of a sample 10 containing a foreign substance having a property of absorbing light. min 5A is a graph showing a schematic distribution of the LDI distribution in the case of a foreign object having a property of reflecting light. max As shown in Figure 5b, in the case of a foreign object that has the property of absorbing light, the optical characteristic value LDI is maximized at the center of the foreign object. min It can be confirmed that is the minimum.

[0040] On the other hand, when multiple foreign objects are present in the sample 10, if the sample 10 placed on the stage 100 is flat and not bent, only one reference plane S is determined, and then high magnification images are continuously taken by the high magnification optical module 400 for each foreign object coordinate area based on the reference plane S, and analysis of the depth d of each foreign object and the height h of each foreign object, etc., can be repeatedly performed. However, if the sample 10 placed on the stage 100 is bent, a reference plane S must be determined separately for each foreign object and applied to the analysis of each foreign object. For example, referring to FIG. 6, in a bent sample 10, for foreign object F1, the height of the high magnification optical module 400 at focal length 1 relative to the top surface of the sample is the reference plane S1, and for foreign object F2, the height of the high magnification optical module 400 at focal length 2 relative to the top surface of the sample is the reference plane S2. When determining the foreign object presence depth for foreign object F1, foreign object analysis unit 580 calculates the vertical distance down from reference plane S1, and when determining the foreign object presence depth for foreign object F2, it calculates the vertical distance down from reference plane S2.

[0041] The determination unit 590 can determine whether the sample 10 is normal or defective depending on which layer or position the foreign matter presence depth d is in. When foreign matter is present in the upper protective layer 12 and the lower protective layer 13 of the sample 10 such as an OCA film, it is determined to be a normal product that can be used, and when foreign matter is present in the base layer 11, it is determined to be a defective product that cannot be used. In addition, the determination unit 590 can make a determination by taking into account the height h of the foreign matter analyzed by the foreign matter analysis unit 580.

[0042] As an example, if the total thickness of sample 10 made of OCA film is 40 μm, the thickness of base layer 11 is 20 μm including the adhesive surfaces on both sides, and upper protective layer 12 and lower protective layer 13 are each 10 μm, if the foreign matter presence depth d is 4 μm from the top end surface of the sample, the sample 10 can be judged as a normal product because the foreign matter exists in the upper protective layer 12, but if the height of the foreign matter is not taken into consideration, an error in the judgment may occur. Therefore, if the height h of the foreign matter is 3 μm, it is judged as a normal product because it does not affect the base layer 11, and if the height h of the foreign matter is 6 μm or more, the foreign matter is in contact with the base layer 11 and may be transferred to the base layer 11, or exists across the upper protective layer 12 and base layer 11, and is therefore judged as a defective product.

[0043] The foreign matter analysis unit 580 may measure the distance between the foreign matters detected in the low magnification image, and the determination unit 590 may take into consideration the size of the detected foreign matter and the distance between the foreign matters in the determination. For example, when a plurality of foreign matters are detected in the low magnification image captured by the low magnification optical module 300, the foreign matter analysis unit 580 may measure the distance between the detected foreign matters by comparing the size of the detected foreign matters with a reference value while obtaining the foreign matter existence depth d and the foreign matter height h. Thus, in the sample 10 made of a multilayer film, if foreign matters are present in the base layer 11 but the size of the foreign matters is equal to or smaller than the reference value and the distance between the foreign matters is greater than the reference distance, it is determined that the foreign matters do not adversely affect the quality and is determined as a normal product, and if foreign matters are present in the base layer 11 but the size of the foreign matters is equal to or smaller than the reference value and the distance between the foreign matters is greater than the reference distance, it is determined that the foreign matters adversely affect the quality and is determined as a defective product.

[0044] A foreign matter type analyzer can be connected to the high magnification optical module 400 to analyze the type of foreign matter contained in the sample 10. For example, a Raman spectrophotometer, a Fourier transform infrared spectroscopy (FT-IR), or the like can be connected to the high magnification optical module 400 to analyze the type of foreign matter. Foreign matter analysis using a foreign matter type analyzer is a well-known technology, and therefore a detailed description thereof will be omitted.

[0045] Hereinafter, the operation of the high speed automatic film foreign substance detection device of the present invention will be briefly described through one embodiment with reference to Figs. 7a and 7b.

[0046] Sample 10 uses an OCA film and has a total thickness of 40 μm, of which the thickness of the base layer 11 is 20 μm including the adhesive surfaces on both sides, and the thickness of the upper protective layer 12 and the lower protective layer 13 are each 10 μm. The optical characteristic values ​​are calculated from the RGB values ​​by LDI. max or LDI min As described above, the range of the sample upper end surface reference value and the range of the foreign matter reference value, which are previously derived for the OCA film through the test, are stored in the reference value storage unit 510. At this time, these values ​​are used as the LDI max or LDI min is calculated and stored.

[0047] As an example, the R, G, and B values ​​are extracted for each pixel in a high-magnification image captured by manually focusing the high-magnification optical module 400 on the top surface of a sample without any foreign matter of an OCA film. max =190, G max =190, B max =100 is extracted, and DI max = 3,610,000. This procedure is repeated for multiple points on the top surface of the sample to obtain 3,500,658 ≦ LDI. max A range of sample top surface criteria of ≦3,721,062 was derived.

[0048] In addition, a foreign object having a size of 5 μm and a property of reflecting light was artificially included between the base layer 11 and the upper protective layer 12 of the OCA film, and then the foreign object coordinate area was manually focused on the high magnification optical module 400, and the RGB values ​​extracted for each pixel in the high magnification image were calculated. max =250, G max =250, B max = 150 is extracted, and LDI max = 9,375,000. In addition, the foreign matter is included in several positions of the OCA film, and this procedure is repeated to obtain 9,102,592 ≦ LDI. max A range of foreign matter criteria was derived.

[0049] In addition, a foreign substance having a size of 5 μm and a property of absorbing light was artificially included between the base layer 11 and the upper protective layer 12 of the OCA film, and then the foreign substance coordinate area was manually focused on the high magnification optical module 400, and the RGB values ​​extracted for each pixel in the high magnification image were extracted. min =125, G min = 125, Bmim = 60 are extracted, and LDI min = 937,500. This procedure was also repeated by adding the foreign matter to several positions of the OCA film to obtain LDI. min A range of foreign matter criteria of ≦992,124 was derived.

[0050] First, the OCA film sample 10 is placed on the stage 100, the lights of the side light units 200 are turned on, and the low-magnification optical module 300 captures a low-magnification image of the sample 10 in a wide imaging area of ​​200 mm wide x 150 mm long, and transmits the image to the user device 500. The optical module control unit 550 can adjust the imaging area to match the sample 10 by sending a signal to the low-magnification driving unit 310 to drive and control the low-magnification optical module 300 in the vertical direction. At this time, the high-magnification optical module 400 waits outside the field of view of the low-magnification optical module 300. The region of interest extraction unit 520 cuts out and extracts the region of interest R from the low-magnification image along the boundary line L that is reflected by the side light irradiated from the side light unit 200 and displayed as a light line. The foreign object detection unit 530 detects foreign objects by using the light scattering of foreign objects caused by the side light irradiated from the side light unit 200 within the region of interest R of the low-magnification image.

[0051] The coordinate determination unit 540 derives the foreign object coordinate area in which a foreign object is detected in the region of interest R, matches the imaging area of ​​the high magnification optical module 400 with the foreign object coordinate area, and searches for and determines an adjacent coordinate area in which no foreign object is present within the area of ​​the sample 10 adjacent to the foreign object coordinate area.

[0052] The optical module control unit 550 transmits a signal to the high magnification driving unit 410 to control the driving in the x-axis and y-axis directions so that the high magnification optical module 400, which was waiting outside the field of view of the low magnification optical module 300, moves to an adjacent coordinate area, then turns on the direct light unit 420 and controls the high magnification optical module 400 to move in the z-axis direction from the adjacent coordinate area by 0.1 μm each time to continuously capture high magnification images, and the captured high magnification images are transmitted to the user device 500.

[0053] The optical characteristic value extracting unit 560 extracts RGB values ​​from the high magnification image and outputs the LDI max The reference plane determination unit 570 calculates the LDI derived from the high magnification image. max is within the range of the upper end surface reference value of the sample (3,500,658≦LDI max≦3,721,062), the height at which the high magnification optical module 400 is located is determined as a reference plane S. Next, the optical module control unit 550 controls the high magnification driving unit 410 to move the high magnification optical module 400 horizontally along the reference plane S from the adjacent coordinate area to the foreign object coordinate area.

[0054] Then, the optical module control unit 550 sends a signal to the high magnification driving unit 410 to control the high magnification optical module 400 to turn on the direct light unit 420 and descend in the z-axis direction by 0.1 μm in the foreign object coordinate area to continuously capture high magnification images across the entire thickness of the sample 10, and the captured high magnification images are transmitted to the user device 500.

[0055] The optical characteristic value extracting unit 560 extracts RGB values ​​from the high magnification image and outputs the LDI max The foreign body analysis unit 580 calculates the LDI derived from the high magnification image. max is within the range of the foreign matter standard value (9,102,592≦LDI max ) is included in the high magnification optical module 400, the vertical distance down from the reference plane S is calculated to derive the foreign object existence depth d. For example, max is derived as 9,114,147, if the vertical distance that the high magnification optical module 400 has descended from the reference plane S at that time is 4 μm, then the foreign matter presence depth d can be determined to be 4 μm from the upper end surface of the sample. In such a case, since the foreign matter is present in the upper protective layer 12, the judgment unit 590 can judge the sample 10 to be a normal product that can be used.

[0056] However, the foreign body analyzer 580 uses the LDI derived from the high magnification image. max is within the range of the foreign matter standard value (9,102,592≦LDI max), the height h of the foreign object can be determined by calculating the vertical distance between the start position of the high magnification optical module 400 where the foreign object reference value range started and the end position of the high magnification optical module 400 where the foreign object reference value range ended. For example, the LDI derived from the high magnification image when the high magnification optical module 400 descends vertically from the reference plane S by 4 μm can be calculated as follows: max is the first to fall within the range of the foreign object reference value, and the LDI derived from the high magnification images continuously taken while the high magnification optical module 400 continues to descend. max The LDI derived from the high magnification image when the high magnification optical module 400 is lowered vertically from the reference plane S by 10 μm while the range of the foreign object reference value is still included. max is finally included in the range of the foreign matter reference value, the foreign matter height h is 10 μm-4 μm=6 μm. In such a case, the foreign matter is present in the upper protective layer 12, but is in contact with the base material layer 11, and there is a possibility that the foreign matter will transfer to the base material layer 11 when the upper protective layer 12 is removed during use of the sample 10, and therefore the sample is judged to be defective.

[0057] In addition, in the case of the sample 10 containing foreign matter having a property of absorbing light, such as carbon black, it is not possible to confirm this in advance. Therefore, in the present invention, as described above, the optical characteristic values ​​are first measured by the LDI. max Then apply the pre-saved LDI max If the optical properties are not within the range of the foreign object standard value for the LDI, the optical properties are evaluated in the following order: min If applied, LDI min For example, if the LDI from a high magnification image is within the range of the standard value for foreign matter, analysis of the foreign matter becomes possible. min When the LDI was calculated as 915,120, the range of the foreign matter standard value (LDI min ≦992,124) and the vertical distance that the high magnification optical module 400 has descended from the reference plane S at that time is 35 μm, then the foreign matter presence depth d can be determined to be 35 μm from the upper end surface of the sample, and in this case, since the foreign matter is present in the lower protective layer 13, the judgment unit 590 can judge the sample 10 to be a normal product that can be used. [Industrial Applicability]

[0058] The high-speed automatic film foreign body detection device of the present invention can detect foreign bodies contained in a sample using a light scattering image captured by a low-magnification optical module, and can identify the shape, color, size, and optical characteristic values ​​of the foreign body by moving the high-magnification optical module to the foreign body coordinate area of ​​the sample.It can quickly determine whether the product is usable by identifying the layer and depth in which the foreign body exists and the height of the foreign body without damaging the sample, and can also identify the type of foreign body by connecting a foreign body analyzer, making it industrially applicable.

Claims

1. a low-magnification optical module that is installed on one side of the table and is connected to a high-magnification driving unit and is driven in x-axis, y-axis and z-axis directions to image the sample and generate a high-magnification image; and a user device that controls the operation of the low-magnification optical module and the high-magnification optical module, and receives the low-magnification image and the high-magnification image, and stores, reproduces and analyzes the low-magnification image and the high-magnification image. The user device derives a foreign object coordinate area in which a foreign object is detected from the low magnification image, controls the high magnification optical module to move to an adjacent coordinate area in which no foreign object is present and is adjacent to the foreign object coordinate area, and causes the high magnification optical module to continuously capture high magnification images while moving in a z-axis direction by a certain numerical value in the adjacent coordinate area, compares optical characteristic values ​​extracted from the captured high magnification images with a range of reference values ​​for the upper end surface of the sample, and determines a height of the high magnification optical module when the optical characteristic value falls within the range of reference values ​​for the upper end surface of the sample as a reference surface. and then, after the high magnification optical module is horizontally moved from the adjacent coordinate area to the foreign object coordinate area along a reference surface, the high magnification optical module is caused to descend in a z-axis direction from the reference surface by a certain numerical value in the foreign object coordinate area to continuously capture high magnification images. Optical characteristic values ​​extracted from the captured high magnification images are compared with a range of foreign object reference values, and a distance that the high magnification optical module has descended from the reference surface when the optical characteristic value falls within the range of the foreign object reference values ​​is determined to be a foreign object presence depth.

2. 2. The high-speed automatic film foreign matter detection device according to claim 1, wherein the side light unit has a light irradiation angle of 5 to 45 degrees with respect to the sample.

3. 2. The high-speed automatic film foreign body detection device according to claim 1, wherein the low-magnification optical module is connected to a low-magnification driving unit and is driven and controlled in the vertical direction, and the high-magnification optical module is provided at its lower part with a direct light unit for irradiating a direct light toward a sample.

4. the user device includes a reference value storage unit for storing a range of sample upper surface reference values ​​for optical characteristic values ​​extracted from a high magnification image of the upper surface of a sample previously captured by the high magnification optical module, and a range of foreign matter reference values ​​for optical characteristic values ​​extracted from a high magnification image of a foreign matter-containing region captured by the high magnification optical module after the sample is previously impregnated with foreign matter; a foreign object detection unit that detects foreign objects from a low-magnification image of a sample captured by the low-magnification optical module by utilizing light scattering of the foreign objects caused by side light irradiated from a side light unit; a coordinate determination unit that derives a foreign object coordinate area where a foreign object is detected from the low magnification image, matches an imaging area of ​​the high magnification optical module with the foreign object coordinate area, and determines an adjacent coordinate area where no foreign object is present and is adjacent to the foreign object coordinate area; an optical module control unit which controls the low magnification optical module and the high magnification optical module to capture images, controls the high magnification optical module in the x-axis and y-axis directions by transmitting a control signal to a high magnification driving unit to move the high magnification optical module to a foreign object coordinate area or an adjacent coordinate area adjacent to the foreign object coordinate area and free of foreign objects, controls the high magnification driving unit in the adjacent coordinate area to move the high magnification optical module in the z-axis direction by a certain numerical value to continuously capture high magnification images, and when a reference plane is determined, controls the high magnification driving unit to horizontally move the high magnification optical module from the adjacent coordinate area to the foreign object coordinate area along the reference plane, and then controls the high magnification driving unit in the foreign object coordinate area to continuously capture high magnification images while the high magnification optical module descends in the z-axis direction by a certain numerical value from the reference plane; an optical characteristic value extracting unit for extracting optical characteristic values ​​from the high magnification image captured by the high magnification optical module and received; a reference plane determination unit that compares optical characteristic values ​​extracted from the high magnification images successively captured in the adjacent coordinate regions with a range of the sample upper end surface reference values, and determines, as a reference plane, the position of the high magnification optical module when the high magnification image from which the optical characteristic value included in the range of the sample upper end surface reference values ​​was extracted was captured; a foreign matter analysis unit for comparing optical characteristic values ​​extracted from high magnification images successively captured in the foreign matter coordinate region with the range of the foreign matter reference value, and calculating a vertical distance downward from a reference plane of the high magnification optical module when capturing the high magnification image from which an optical characteristic value included in the range of the foreign matter reference value is extracted, thereby determining a depth of the foreign matter present in the sample; and 2. The high speed automatic foreign matter detection device for a film according to claim 1, further comprising a determination unit for determining whether a sample is normal or defective based on the depth of the foreign matter.

5. 5. The apparatus for automatically detecting foreign matter in a film according to claim 4, wherein, when the sample is a multilayer film having a base layer and protective layers attached to both sides of the base layer, one of the protective layers to be removed during use is formed with an area larger than that of the base layer, a boundary between the base layer and one of the protective layers is displayed as a colored line in a low-magnification image by side light irradiated from a side light unit, and the apparatus further comprises a region of interest extraction unit that cuts out the boundary displayed as the colored line from the low-magnification image and extracts it as a region of interest, and the foreign matter detection unit detects foreign matter in the region of interest.

6. 5. The device for automatically detecting foreign matter in a film according to claim 4, wherein the foreign matter analysis unit determines the height of the foreign matter by calculating the vertical distance between a start position of the high magnification optical module where an optical characteristic value extracted from high magnification images continuously captured while the high magnification optical module is descended in the foreign matter coordinate area begins to fall within a range of the foreign matter reference value, and an end position of the high magnification optical module where the optical characteristic value last falls within the range of the foreign matter reference value.

7. 5. The high-speed automatic foreign substance detection device of claim 4, wherein the foreign substance analysis unit measures a distance between foreign substances detected in the low magnification image, and the determination unit determines whether a sample is normal or defective in consideration of the size of the detected foreign substances and the distance between the foreign substances.

8. The optical characteristic value is any one selected from RGB values, YUV values, HSB values, and Lab values. When the optical characteristic value is used as an RGB value, the following Layer Detectable Maximum Index (LDI) is used: ｍａｘ ) is calculated and used, LDI ｍａｘ is LDI ｍａｘ = R ｍａｘ xG ｍａｘ ×B ｍａｘ and R ｍａｘ is the maximum value of the R component values ​​of the pixels in the high magnification image capturing area, G ｍａｘ is the maximum value of the G component values ​​of the pixels in the high magnification image capturing area, B ｍａｘ 2. The high-speed automatic film foreign substance detection device according to claim 1, wherein: is the maximum value of the B component values ​​of pixels in the high magnification image pickup area.

9. The optical characteristic value is any one selected from RGB values, YUV values, HSB values, and Lab values. When the optical characteristic value is used as an RGB value, the following layer detectable minimum index (LDI) is used: ｍｉｎ ) is calculated and used, LDI ｍｉｎ is LDI ｍｉｎ = R ｍｉｎ xG ｍｉｎ ×B ｍｉｎ and R ｍｉｎ is the minimum value of the R component values ​​of the pixels in the high magnification image capturing area, G ｍｉｎ is the minimum value of the G component values ​​of the pixels in the high magnification image capturing area, B ｍｉｎ 2. The high speed automatic film foreign substance detection apparatus according to claim 1, wherein: is the minimum value of the B component values ​​of pixels in the high magnification image capture area.

10. 2. The high-speed automatic foreign matter detection apparatus of claim 1, further comprising a foreign matter type analyzer connected to the high magnification optical module for determining the type of foreign matter contained in the sample.

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