JP2006322731A - Visual inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual inspection device capable of observing flaws having various forms, when the visual inspection of a substrate is conducted. <P>SOLUTION: The visual inspection device has a digital camera 17, capable of acquiring the image of a substrate to be inspected from an arbitrary position and a control unit 20 for processing the image of the digital camera 17 to output it to a display means 32. The control unit 20 is constituted so as to extract the contour line of the substrate to be inspected from the image acquired by the digital camera 17, to divide it into a large number of squares so as to perform shape correction. When the image of the substrate to be inspected is processed and outputted to the display means 32, a large number of the squares are allotted to rectangular shapes to adjust the aspect ratio so that it matches the aspect ratio of the substrate to be inspected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an appearance inspection apparatus for inspecting the appearance of a substrate.

When manufacturing a flat panel display such as a liquid crystal display, a pattern such as a filter is formed on a glass substrate. In such a flat panel display manufacturing process, the appearance of the glass substrate is visually inspected by an appearance inspection apparatus to check for defects such as film unevenness and adhesion of foreign matter (macro inspection), and the defects are installed in the apparatus. In addition, there is a process of inspecting and inspecting in detail with a stereo microscope (micro inspection). In the conventional visual inspection apparatus used for such an inspection process, for example,
The surface light source by the macro illumination unit is irradiated on the surface of the substrate to be inspected on the holder, the change in the reflected light on the surface of the substrate to be inspected is detected as a defective portion by the observer's visual observation, and the defective portion on the substrate to be inspected is detected. The image is captured with a fixed TV camera, the position coordinates of the defect are detected by image processing, and the defective part on the substrate to be inspected is automatically moved to the observation range of the objective lens of the micro observation unit based on the coordinate data. In some cases, the microscopic observation with an eyepiece lens can be performed to reduce the burden of observation work (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 10-111253 (FIG. 6)

The illumination light applied to the substrate is reflected in various directions due to light diffraction and interference on the pattern, so that the appearance of the defect also differs depending on the location. Therefore, there is a case where a defect cannot be found only by acquiring an image of a substrate from a predetermined direction as in the prior art. In particular, a substrate that has been increased in size in recent years has defects that are difficult to find unless observed from a position away from the substrate, in addition to defects that can be confirmed at a position close to the substrate. However, the conventional visual inspection apparatus cannot observe such various defects from an arbitrary position, acquire an image, and specify the position of the defect from the image. Therefore, it has been desired to be able to acquire an image of a defect from an arbitrary position away from the substrate and to specify the position of the defect from the image.
The present invention has been made in view of such circumstances, and a main object thereof is to make it possible to specify the position of a defect from a macro image captured from an arbitrary position when performing an appearance inspection of a substrate. This is to improve the efficiency of the inspection.

  The present invention for solving the above-described problems includes a stage that holds a substrate to be inspected, a macro image acquisition unit that can acquire an image from an arbitrary position with respect to the substrate to be inspected as a macro image, and the macro image acquisition A visual inspection apparatus comprising: a control unit that performs processing for correcting a rectangular image on the substrate to be inspected in the macro image acquired by the unit into a rectangular shape.

  In this appearance inspection apparatus, after a substrate to be inspected is held on a stage, a wide range image (macro image) of the substrate to be inspected is acquired from an arbitrary position using a macro image acquisition unit. The rectangular area (rectangular portion) of the board to be inspected in the macro image has a distorted shape depending on the position where the macro image of the board to be inspected is acquired. Therefore, the control unit performs image processing on the macro image and corrects the shape so as to be rectangular.

  According to the present invention, by performing image processing with a control unit on a macro image captured from an arbitrary position, even if the image of the substrate to be inspected in the macro image has a shape other than a rectangle, Since the shape can be corrected in a rectangular shape like the substrate to be inspected, the position on the substrate to be inspected can be specified from the macro image. Therefore, since the defect position can be easily identified, the work efficiency can be improved and the inspection efficiency can be improved.

The best mode for carrying out the present invention will be described below.
FIG. 1 shows a schematic configuration of an appearance inspection apparatus according to the present embodiment. The appearance inspection apparatus 1 has an apparatus main body 2 installed on a floor surface, and a stage 4 is supported by the apparatus main body 2 by a rotation drive mechanism 3 so that the stage 4 can be raised. On the stage 4, a substrate W to be inspected such as a glass substrate, a color filter, and a semiconductor wafer is placed. The stage 4 is provided with positioning pins 5 and 6 and a suction mechanism (not shown) so that the inspected substrate W can be positioned and held. In addition, a macro illumination unit 8 is provided on the upper part of the apparatus main body 2. The macro illumination unit 8 illuminates the inspection substrate W on the stage 4 from above, and is composed of an optical system such as a light source, a mirror, and a lens. Note that the macro illumination unit 8 desirably constructs an optical system so as to irradiate the inspected substrate W with convergent light. This is because when the inspected substrate W is illuminated with the convergent light, the inspector P standing on the front side of the apparatus body 2 can easily visually observe defects such as foreign matters on the inspected substrate W.

  Further, a Y-axis guide 10 (guide means) is slanted over the apparatus body 2. The inclination angle of the Y-axis guide 10 is set so as to be substantially parallel to the inspected substrate W when it rises to the inspection position. The lower end and the upper end of the Y-axis guide 10 are movably attached to a pair of X-axis guides 11 (guide means). The X axis guide 11 is disposed so as to be orthogonal to the Y axis guide 10. A micro image acquisition unit 12 for acquiring an enlarged image (micro image) of the substrate surface is attached to the Y axis guide 10 so as to be slidable in the longitudinal direction of the Y axis guide 10. Therefore, when the inspected substrate W is raised and raised, the micro image acquisition unit 12 can move the upper portion of the inspected substrate W in parallel to the surface of the inspected substrate W. At this time, a direction parallel to the X-axis guide 11 is defined as an X direction, and a direction parallel to the Y-axis guide 10 is defined as a Y direction.

  Here, the micro image acquisition unit 12 includes a microscope 15 and a digital camera 17 detachably attached to the microscope 15 via a fixing unit 16. The microscope 15 is a stereomicroscope having a magnifying optical system. In this embodiment, an adapter to which the digital camera 17 can be attached is installed instead of the eyepiece unit. A half mirror that splits the optical path may be disposed in the intermediate lens barrel while leaving the eyepiece portion as it is, and a digital camera mounting adapter may be installed on one of the split optical paths. This adapter has an optical system in which the focal length on the exit side is infinite so that a micro image of the substrate surface can be taken by the digital camera 17. The digital camera 17 includes a CCD (Charge Coupled Device). When the digital camera 17 is detached from the fixed unit 16, the digital camera 17 becomes a macro image acquisition unit that can acquire the entire image (macro image) of the substrate to be inspected from an arbitrary position. The macro image may be an image that covers a wider range than the micro image, and does not necessarily have to be an image that fits the entire substrate W to be inspected. The back of the digital camera 17 is provided with a display using liquid crystal, organic EL (Electro Luminescence), or the like. Furthermore, if the macro image magnification of the digital camera 17 can be sufficiently secured, the microscope 15 may be omitted and fixed to the fixed unit 16 so that micro imaging of a defect can be directly performed.

  A data transfer cable 18 is drawn into the fixed unit 16, and the data transfer cable 18 can be connected to the data transfer connector 17 a on the digital camera 17 side with the digital camera 17 attached to the fixed unit 16. The data transfer cable 18 is inside a caterpillar 19a provided along the Y-axis guide 10 so as to move the microscope 15 in the Y direction, and along the X-axis guide 11 so as to move the Y-axis guide 10 in the X direction. It passes through the provided caterpillar 19b and is connected to the control unit 20 shown in FIG.

  The control unit 20 is composed of a CPU (Central Processing Unit), a memory, and the like, and is a device that collectively controls the appearance inspection apparatus 1 shown in FIG. 1, and performs division processing and shape correction processing as will be described in detail later. It also functions as image processing means for performing the above. In addition to the digital camera 17, the control unit 20 includes a stage control unit 25, a macro illumination control unit 26, a guide control unit 27, an X coordinate reading unit 28, a Y coordinate reading unit 29, an image storage means 30, and an operation unit. 31 and display means 32 are connected.

  The stage control unit 25 controls the stage 4 and the rotation drive mechanism 3. The stage control unit 25 controls the rotation of the stage 4 from the horizontal position to the inspection position where the position rises from the horizontal position to the vertical position. The vacuum suction of the substrate W to be inspected is controlled. The stage control unit 25 can also perform swing control for swinging the stage 4 in the rotational direction around the inspection position. The macro illumination control unit 26 is provided in the macro illumination unit 8 and controls the brightness for illuminating the inspected substrate W and the irradiation angle. The guide control unit 27 controls the movement of the Y-axis guide 10 and the X-axis guide 11.

  Further, the X coordinate reading unit 28 and the Y coordinate reading unit 29 detect the X coordinate and the Y coordinate of the observation position by the micro image acquisition unit 12, respectively. The X coordinate reading unit 28 is arranged in the X direction of the Y axis guide 10. The amount of movement is detected, and the Y coordinate reading unit 29 is configured to detect the amount of movement of the micro image acquisition unit 12 in the Y direction. The image storage unit 30 is a storage device that stores a micro image or a macro image acquired by the digital camera 17. The operation unit 31 receives the operation of the inspector P, and can perform operations such as illumination brightness, irradiation angle, and rotation angle of the stage 4, and includes a switch, a button, a joystick, and the like. The display means 32 is composed of, for example, a display, and the micro image acquired by the micro image acquisition unit 12, the macro image acquired by the digital camera 17, the image stored in the image storage means 30, the defect coordinates, and the inspection result of the defect. Etc. can be displayed.

Next, the operation of the appearance inspection apparatus 1 will be described.
First, the substrate W to be inspected is placed on the stage 4 held in a horizontal position by a robot (not shown). The positioning pin 5 is driven by the stage control unit 25, and the substrate to be inspected is aligned at a predetermined position so as to be sandwiched between the positioning pins 6 arranged opposite to each other. Further, the inspection target substrate W is vacuum-sucked by the suction mechanism. As a result, the inspected substrate W is held on the stage 4, so that the stage control unit 25 drives the rotation drive mechanism 3 to raise the stage 4 to the inspection position. Further, the macro illumination control unit 26 illuminates the inspected substrate W from above with the brightness and irradiation angle set by the operation unit 31. In this state, the observer P visually inspects the surface of the substrate W to be inspected to check for defects. When no defect is found or when the appearance inspection is completed, the stage 4 is returned to the horizontal position, the suction is released, and the substrate W to be inspected is unloaded.

Here, when a defect is found as a result of the inspector P visually observing the inspected substrate W at the inspection position, an image of the defect is acquired using the micro image acquisition unit 12 and the digital camera 17.
When the defect can be confirmed from a position slightly apart from the substrate W to be inspected, such as a wide range of film unevenness, and only at a specific angle, the digital camera 17 is removed from the fixed unit 16. Then, as shown in FIG. 4, the substrate W to be inspected is photographed by the digital camera 17 from the position where the defect can be best confirmed. In FIG. 4, the digital camera 17 is attached to the fixed unit 16 at the time of imaging with the digital camera 17, but this is schematically illustrated, and actually one same A digital camera 17 is used. Further, FIG. 4 shows a state at the time of micro image acquisition, and at the time of macro image acquisition, the fixed unit 16 and the guide means are retracted to the end as in the macro image D1. Further, the stage 4 is set at an angle at which the defect can be best confirmed. At the time of micro photography, the angle is set parallel to the guide means.

  The macro image D1 acquired at this time is an image captured in a state in which the inspected substrate W is pulled obliquely from the front, and interference fringes indicating the presence of film unevenness can be confirmed on the surface of the inspected substrate W. The macro image D1 is stored in the memory of the digital camera 17, and is automatically transferred from the data transfer connector 17a to the control unit 20 through the data transfer cable 18 when the digital camera 17 is attached to the fixed unit 16. The control unit 20 takes in the image data of the macro image D1 from the digital camera 17 and stores it in the image storage means 30.

  Further, a small defect F that cannot be confirmed without being close to the substrate W to be inspected is imaged in a state where the digital camera 17 is attached to the fixed unit 16 and connected to the microscope 15. At this time, the X-axis guide 11 and the Y-axis guide 10 are moved by the operation unit 31, and the visual field of the microscope 15 is adjusted to the defect position. The image of the defect F acquired at this time is as shown in the micro image D2. Since the image data of the micro image D2 is displayed on the display means 32 through the data transfer connector 17a, the data transfer cable 18, and the control unit 20, the inspector P operates the operation unit 31 after confirming this image, Capture image D2. The image data of the micro image D2 is stored in the image storage means 30. At this time, the X coordinate and Y coordinate of the microscope 15 acquired by the X coordinate reading unit 28 and the Y coordinate reading unit 29 are stored in the image storage unit 30 in association with the image data of the micro image D2 as the coordinate data of the defect position. If there is a defect with a size that can be detected from the macro image D1 captured from an arbitrary position, the defect position is automatically specified by specifying the defect position on the macro board fit image created by the correction process described later. The visual field of the microscope 15 may be adjusted to the defect position.

  Furthermore, the appearance inspection apparatus 1 can display various images taken by the digital camera 17 on the display unit 32 to perform various types of analysis. At this time, the macro image D1 is picked up from various angles with respect to the substrate W to be inspected. Therefore, the image of the substrate W to be inspected which is originally a rectangle has a distorted shape, and the macro is left as it is. It is difficult to specify the X coordinate and the Y coordinate on the inspected substrate W from the image D1. For this reason, as shown in FIG. 5, the image of the substrate W to be inspected in the non-rectangular macro image D1 is subjected to image processing by the control unit 20, and shape correction processing for converting the image into a rectangle is performed. That is, the shape correction is performed so that the outer edge (rectangular portion) of the distorted substrate W to be inspected becomes a rectangle in the macro image D1.

In this shape correction process, a division process for dividing the image of the inspected substrate W into four quadrangles in the macro image D1 is first executed. The processing at this time will be described with reference mainly to the flowchart of FIG.
The control unit 20 performs image processing to extract a contour portion of the inspected substrate W from the macro image D1 (step S101). For example, when a contour portion such as a quadrangle shown in FIG. 5 is extracted, the vertices are set to A ₀ , B ₀ , C ₀ , D _{0 in the} counterclockwise direction from the upper right, and the straight line A ₀ B ₀ , straight line The lengths of C ₀ D ₀ , straight line B ₀ C ₀ , and straight line A ₀ D ₀ are La, Lb, Lc, and Ld, respectively (step S102). Further, let p be the point where the straight line A ₀ B ₀ is divided from the point B ₀ to Lc: Ld, and q be the point where the straight line C ₀ D ₀ is divided from the point C ₀ to Lc: Ld (step S103). Similarly, let r be the point that divides the straight line B ₀ C ₀ from point B ₀ to La: Lb, and let s be the point that divides the straight line A ₀ D ₀ from point A ₀ to Lc: Ld (step S104). Further, an intersection of the straight line pq and the straight line rs when a line segment connecting the points p and q is a straight line pq and a line segment connecting the points r and s is a straight line rs is set as a point E (step S105). A square image surrounded by four points A ₀ pEs is defined as a square A. Similarly, a quadrilateral image surrounded by the point pB ₀ rE is a quadrangle B, a quadrilateral image surrounded by the point ErC ₀ q is a quadrangle C, and a quadrilateral image surrounded by the point sEqD ₀ is a quadrilateral D (step) S106). As a result, as shown in FIG. 5, the quadrangle A corresponding to the first quadrant, the quadrangle B corresponding to the second quadrant, the quadrangle C corresponding to the third quadrant, and the quadrangle D corresponding to the fourth quadrant with the point E as the center. Is created.

  Further, for each of the quadrilaterals A, B, C, and D, step S102 to step S106 in FIG. 6 are repeated to divide the quadrangle into smaller squares. At this time, the quadrangle A when the quadrangle A is divided into four is AA, AB, AC, and AD. Similarly, when the quadrangle B is divided into four, the quadrangle is BA, BB, BC, and BD. In this way, each time the division is performed, the code specifying the quadrangle is incremented by one. Thus, for example, in the case of a rectangle AAAAAAAAA, it can be seen that the division process has been repeated eight times and that this rectangle is a rectangle corresponding to the upper right. Then, the division process for dividing the image into four is repeated, and when any one of the square images reaches the minimum image (pixel) unit, that is, one pixel (one pixel), the division process ends.

  FIG. 7 shows an overall flowchart of the shape correction process performed after the division process is performed in this way. When the above-described division process is performed and repeated until any one of the square images becomes the minimum pixel unit (step S201), some of the remaining square images are not divided to the minimum pixel. Each square pixel is aligned with the minimum pixel (step S202). Specifically, an average value of luminance information of each pixel of a quadrangle composed of a plurality of pixels is calculated, and the average value is set as luminance information of the quadrangle. For example, when one square is represented by four pixels g1 to g4 as shown in FIG. 8, luminance information (R, G, B) of the four pixels g1 to g4 = (80, 150, 100) , (82, 151, 98), (83, 151, 101), (79, 152, 97) are replaced with one pixel p5 having an average value (81, 152, 97). Instead of the average value of the luminance information, the maximum value or the minimum value of the luminance information may be the luminance information of the rectangle.

When all the rectangles are aligned with the minimum pixels, all the rectangles become rectangles, and the rearrangement process of these rectangles (minimum pixels) is executed (step S203). A specific example of the rearrangement process will be described with reference to FIG. FIG. 9 shows an example in which the division process is executed three times for easy understanding.
As shown in FIG. 9, in the quadrangle AAB, which is an image that has become a rectangle by the minimum pixelization, attention is first paid to the first character (the leftmost digit) of the character string “AAB” that identifies the quadrangle. In this case, since it is “A”, the predetermined area is assigned to the first quadrant of the quadrant. Next, paying attention to the second character (second digit from the left), since this character is also “A”, the first quadrant is assigned to the first quadrant further divided into four. Since the third character (the rightmost character) is “B”, it is assigned to the second quadrant of the first quadrant. In this way, the rearrangement process is executed for all the rectangles. When the N-time (N: positive integer) division processing is performed, the image is restored to a 2 ^N × 2 ^N rectangular quadrangle by restoration. FIG. 10 shows a quadrangular arrangement after the eight-time division process. Each quadrilateral image consists of one pixel, and the whole is a rectangle with one side of 258 pixels. In this way, by correcting the shape of the image to a rectangle, the X coordinate and the Y coordinate in the corrected image of the inspected substrate W can be specified.

  Furthermore, since the vertical and horizontal sizes of the inspected substrate W to be inspected are known in advance from the substrate ID, the control unit 20 expands and contracts the entire image in accordance with the actual aspect ratio of the inspected substrate W (step S204). ). The macro image created by this processing is equal to the aspect ratio of the actual inspected substrate W, and the actual position on the inspected substrate W and the position in the image of the inspected substrate W whose shape has been corrected are one-to-one. It becomes easy to correspond to. Hereinafter, an image of the inspected substrate W restored so as to be equal to the aspect ratio of the inspected substrate W is referred to as a macro substrate fit image D3. Note that the digital camera 17 desirably includes an optical system in which distortion is favorably corrected. When the digital camera 17 is photographed in a wide-angle region, an optical system having a tall distortion may be obtained. In that case, the shape correction processing is performed after performing image processing for removing distortion from the aberration data of the optical system of the digital camera 17.

Next, display examples of the macro image D1 and micro image D2 acquired by the digital camera 17 and the macro board fit image D3 created by the control unit 20 will be described with reference to FIG.
FIG. 11 shows the defect image display unit 40 displayed on the display means 32. The defect image display unit 40 includes a substrate ID display field 41 as information for specifying the substrate W to be inspected, and an enlarged display unit 42 on which an image is enlarged. The enlarged display unit 42 displays a substrate map in which a defect position mark 43 indicating the position of a defect is superimposed on the macro substrate fit image D3. The defect position mark 43 is displayed on the macro substrate fit image D3 so as to coincide with the X coordinate and the Y coordinate of the observation position where the micro image D2 is acquired. Note that the control unit 20 may acquire coordinate data of a defect detected by another visual inspection apparatus, and display the defect position mark 43 in an overlapping manner on the macro substrate fit image D3 according to the coordinate data. Further, the form of the defect position mark 43 is not limited to a black circle.

A defect coordinate display unit 45 is provided on the side of the enlarged display unit 42, and when one defect position mark 43 is designated, the coordinates are displayed numerically. The X coordinate and the Y coordinate are displayed as values based on a predetermined position (for example, the right corner) of the inspected substrate W.
Below the enlarged display section 42, a defect image thumbnail display section 48 is provided in which the micro image D2, the macro image D1, and the macro board fit image D3 stored in the image storage means 30 are displayed as a list of small images. It has been. The defect image thumbnail display portion 48 is provided with a scroll bar 49 so that a large number of images can be displayed. In the defect image thumbnail display section 48, an emphasis display 50 such as a thick frame of the image is made so that the selected image can be easily confirmed. Then, the micro image D2, the macro image D1, and the macro substrate fit image D3 selected by the defect image thumbnail display unit 48 are enlarged and displayed on the enlarged display unit 42.

  An enlargement button 46 and a reduction button 47 are provided above the defect coordinate display unit 45 so that an image displayed on the enlargement display unit 42 can be enlarged or reduced. When defects are concentrated in one place, it becomes difficult to discriminate the defects on the screen. In such a case, the defect is enlarged and displayed by pressing the enlarge button 46 through the operation unit 31. Two defects can be separated and discriminated. After the defect determination is completed, if the reduction button 47 is pressed, the enlarged image can be quickly restored.

Furthermore, in the appearance inspection apparatus 1, it is possible to move the micro image acquisition unit 12 to the actual observation position to a position corresponding to the images D1, D2, and D3 displayed on the display unit 32 and acquire the micro image D2. It has become.
First, when the operation unit 31 (see FIG. 3) is operated and a specific defect position mark 43 is selected on the macro board fit image D3 displayed on the enlarged display unit 42, the control unit 20 detects the defect position. The coordinates of the mark 43 are acquired. The control unit 20 outputs a command to the guide control unit 27, and acquires the Y-axis guide 10 and the micro image so that the center of the field of view of the microscope 15 of the micro image acquisition unit 12 is at a position corresponding to the coordinates of the defect position mark 43. The unit 12 is moved. The micro image D2 captured from the micro image acquisition unit 12 at this position is displayed as a live image D4 on the defect live image display unit 51 provided below the defect coordinate display unit 45.
When a specific micro image D2 is selected in the defect image thumbnail display section 48, the coordinate data of the micro image D2 is input as a target value for the guide control unit 27. The micro image captured from the micro image acquisition unit 12 at this position is displayed on the defect live image display unit 51 as a live image D4.

  Further, an X coordinate index line 55 and a Y coordinate index line 56 are provided on the enlarged display unit 42 so that the X coordinate and the Y coordinate can be easily specified, and an arbitrary position including the defect position mark 53 can be designated. good. When the operation unit 31 is operated so as to acquire the live image D4 of the intersection of the X coordinate index line 55 and the Y coordinate index line 56, the coordinates of the intersection are extracted, and the coordinates on the inspection substrate W corresponding to the coordinates are extracted. It is input as a target value for the guide control unit 27. Since the macro substrate fit image D3 is displayed so as to coincide with the XY direction of the actual inspected substrate W, it is easy to grasp the defect position and specify the observation position by operating these index lines 55 and 56. become.

According to this embodiment, since the digital camera 17 is detachably provided on the microscope 15, the micro image D2 can be acquired through the microscope 15 and the macro image D1 can be acquired from a distant position. become. Moreover, since the digital camera 17 can acquire an image from an arbitrary position, it is possible to record information on defects that are easily found at a specific position. Therefore, since it becomes possible to catch a defect reliably, the analysis of a defect becomes easy.
Also, the macro image D1 is divided into four quadrangular images, and the quadrangle is made rectangular by repeating the division process until the quadrilateral image size reaches a predetermined size. It becomes possible to correct the shape of the image D1 to a rectangle. Accordingly, when the portion that is originally a rectangular portion becomes a distorted shape when taken from obliquely forward of the inspected substrate W, the shape of the image can be corrected to a rectangle, and the macro image D1. The inside position can be specified, and the defect can be confirmed more quickly. When this correction is performed, the division process is repeated until at least one quadrangle becomes the minimum pixel, whereby distortion when the image is corrected to a rectangle can be minimized.

The present invention is not limited to the above-described embodiments and can be widely applied.
For example, the micro image acquisition unit and the macro image acquisition unit only need to include a two-dimensional image sensor, and are not limited to those including a CCD.
The guide means is not limited to the X-axis guide 11 and the Y-axis guide 10 and may be an articulated robot. In this case, in order to specify the magnification of the micro image D2, the articulated robot is controlled by the control unit 20 to move the micro image acquisition unit 12 in parallel with the substrate W to be inspected.
As a means for acquiring coordinate data, an encoder may be installed at each joint of the articulated robot to detect the position and shooting angle of the digital camera 17. In addition, the digital camera 17 is provided with a light emitting element, and a CCD camera or a light receiving element provided on the upper part of the apparatus main body 2 is used to image and track the position of the light emitting element to calculate the two-dimensional position of the digital camera 17. The angle and position information of the digital camera 17 with respect to the inspection substrate W at the time of imaging may be acquired. Note that when a plurality of CCD cameras or the like are installed on the upper part of the apparatus body 2 to image and track the light emitting element, the three-dimensional position of the digital camera 17 at the time of macro imaging can be detected. Information on the position and shooting direction can be acquired.

Further, the condition for stopping the division process as shown in FIG. 7 is not limited to the minimum pixel, and may be a size corresponding to several pixels. Even when the smallest number of pixels in the divided rectangle reaches the specified number of pixels, the division is stopped, and the average value of the luminance in each divided rectangle is converted to the luminance value of the rectangular rectangle. good. In this case, it is desirable that the number of pixels designated as the number of pixels to stop the division can be selected.
Furthermore, a multi-joint arm may be provided in the apparatus main body 2 separately from the guides 10 and 11, and a macro image may be acquired in a state where the digital camera removed from the fixed unit 16 is supported by the multi-joint arm. Further, the micro image acquisition unit 12 may be constituted by a stereomicroscope, and the digital camera 17 may only acquire a macro image.

  In addition, the present invention is not applied only to the entire substrate, but is, for example, a rectangular unit in the case of performing multiple chamfering in order to create a plurality of displays on a single glass substrate. It can also be applied to cells. That is, even if the substrate to be inspected is a disk shape like a semiconductor wafer, if there is a rectangular portion in it, it can be applied to it.

It is a figure which shows the structure of the external appearance inspection apparatus which concerns on embodiment of this invention. It is a figure explaining the structure of a micro image acquisition unit, and attachment or detachment of a macro image acquisition unit. It is a control block diagram of an appearance inspection apparatus. It is a figure explaining the usage method of a micro image acquisition unit and a macro image acquisition unit. It is a figure explaining a division process. It is a flowchart of a division | segmentation process. It is a flowchart of the shape correction process including a division process. It is a figure explaining the process which aligns a rectangle with the first pixel. It is a figure explaining the process which allocates a rectangle to a rectangle. It is a figure which shows the state which allocated the rectangle which performed the division | segmentation process 8 times to the rectangle. It is a figure which shows an example of a display means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Appearance inspection apparatus 4 Stage 10 Y-axis guide (guide means)
11 X-axis guide (guide means)
12 Micro Image Acquisition Unit 17 Digital Camera (Macro Image Acquisition Unit)
20 control unit 27 guide control unit 31 operation unit 32 display means 43 defect position mark D1 macro image D2 micro image D3 macro substrate fit image W substrate to be inspected

Claims (8)

  A stage that holds a substrate to be inspected, a macro image acquisition unit that can acquire an image from an arbitrary position with respect to the substrate to be inspected as a macro image, and the target in the macro image acquired by the macro image acquisition unit. A visual inspection apparatus comprising: a control unit that performs processing for correcting a rectangular image on the inspection board into a rectangular shape.   The control unit extracts a contour line of a rectangular portion on the substrate to be inspected in the macro image, performs a division process to divide a region surrounded by the contour line into a plurality of quadrangles, and creates a minute created by the division. The appearance inspection apparatus according to claim 1, wherein a fit image having a shape corrected so that a rectangular portion of the substrate to be inspected in a macro image becomes a rectangle by arranging a rectangular image.   The appearance inspection apparatus according to claim 1, further comprising a display unit that displays an image of the substrate to be inspected, the shape of which is corrected by the control unit.   The control unit is configured to perform a division process until the size of the quadrangle formed by the division becomes the minimum pixel, and rearrange the quadrangle after the division process to create a fit image. The visual inspection apparatus according to claim 2.   The visual inspection apparatus according to claim 3, wherein the control unit is configured to display the display unit with an aspect ratio of the board to be inspected and an aspect ratio of the fit image matched.   The visual inspection apparatus according to claim 5, wherein the control unit is configured to superimpose a defect position mark indicating a defect position on the fit screen and display the defect position mark on the display unit.   A micro image acquisition unit that acquires a micro image that is an enlarged image of a defect on the substrate to be inspected, and a guide unit that movably supports the micro image acquisition unit in parallel with the substrate to be inspected. The appearance inspection apparatus according to any one of claims 1 to 6, wherein the appearance inspection apparatus is characterized. An operation unit for designating a position in the fit image displayed on the display unit, and the micro image acquisition means at an actual position on the substrate to be inspected corresponding to the position in the fit image designated by the operation unit. The visual inspection apparatus according to claim 7, further comprising a guide control unit to be moved.

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