JP2019178928A - Inspection device and inspection method - Google Patents

Abstract

To provide an inspection device and an inspection method which can optimize work man-hours, which can prevent a defective article from flowing out as a nondefective article, and which improve deterioration in yield.SOLUTION: Inspection images at two different times based on a desired inspection parameter stored in inspection parameter storage means are displayed on an inspection image display part. The inspection images at the two different times are compared with each other. Thus, inspection result is determined to be normal or abnormal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inspection apparatus and an inspection method.

  When inspecting whether a pad or the like formed on a substrate has a defect, it is generally performed by image processing. In this case, it is necessary to set inspection parameters. Here, the inspection parameter is a parameter used for inspection, for example, a setting value of a noise removal filter on an image, a setting value serving as a threshold value for determining a pad defect, or the like. For this reason, it is necessary to set an inspection parameter that is optimal for the inspection with respect to the inspection target region to be inspected. In this setting, the parameter criteria (threshold value, etc.) of each inspection parameter is determined (set) by trying and erroring (Try and Error).

  Therefore, the inspection parameter change (adjustment) is sequentially performed. After changing the inspection parameters (after determining the inspection parameters), it is common to visually check the image display unit on the image inspection system and determine whether or not the inspection result is normal. When it is determined that the inspection result is normal, N check of image inspection by automatic operation is performed. Then, the automatic inspection result is compared with the visual inspection result of the image display unit and the actual region to be inspected to confirm that there is a correlation.

  By the way, conventionally, there is a technique in which images for each inspection parameter can be compared, condition selection is facilitated, and labor and time required for condition setting can be reduced (Patent Document 1).

  In this case, first, a plurality of images are acquired by imaging the substrate while changing the image acquisition condition parameter and the inspection condition parameter. The plurality of images are displayed on the screen together with the evaluation finger. Next, an inspection condition is set on this screen, and a defect of a pattern formed on the substrate is inspected based on the set condition.

JP 2004-294358 A

  After changing the inspection parameters (after determining the inspection parameters), the image display unit on the image inspection system is visually confirmed, and it is visually confirmed if the inspection result is normal. For example, in the image inspection on a large workpiece, it is not easy to confirm the range of influence on the inspection result due to the parameter change and the change point of the result because the amount of information is enormous.

  Due to the difficulty of such confirmation, even if there is a defect that is not normally normal, there is a risk that it will be overlooked in the visual confirmation of the image display unit and the actual inspection target part. If the defect was missed in this way, it was commercialized as it was, and the defective product was discharged as a non-defective product, or the yield was deteriorated. For this reason, the inspection parameters are re-changed (adjusted), resulting in an increase in the number of man-hours, and the man-hour is also spent on combining the image inspection result and the visual inspection result.

  In Patent Document 1, image acquisition condition parameters (image size, focal position offset amount, illumination wavelength and light amount, various filter setting conditions, aperture stop, etc.), and inspection parameters (only two defective portions are detected from the detected image). Change binarization threshold for binarization extraction, noise removal threshold for removing small area not related to defect as noise, edge sensitivity reduction parameter, etc. This is what distinguishes the differences. By configuring in this way, it is intended to support setting of inspection conditions used for inspection of defects (short circuit, disconnection, etc.) of the pattern to be inspected.

  However, in the thing of patent document 1, since it is what distinguishes the difference on the image by the difference in conditions, the past data (image) of the to-be-inspected site | part of a workpiece | work under the same conditions (inspection parameter) and the present Comparison with data (image) is not possible. For this reason, it was not possible to detect a defect with the same inspection parameter of the inspection target part of the workpiece.

  In view of the above-described problems, the present invention provides an inspection apparatus and an inspection method that can optimize the number of work steps, prevent outflow of defective products as non-defective products, and improve the deterioration of yield. To do.

  An inspection apparatus according to the present invention is an inspection apparatus that inspects a defect of an inspection target part based on an image of the inspection target part of a workpiece, and an imaging unit that images an inspection image of the inspection target part of the workpiece; Image storage means for storing an inspection image in a region to be inspected, inspection parameter storage means for storing inspection parameters for the region to be inspected, parameter changing means for changing inspection parameters stored in the inspection parameter storage means, Image display means having first and second inspection image display units for respectively displaying inspection images at two different times of the region to be inspected, and the first and second inspection images based on the inspection parameters are Each of the images is displayed on the second inspection image display unit, and the inspection images at two different times are compared to determine whether the inspection result is normal or not. If, by adjusting the test parameters at the parameter changing means is for comparing two test images at different times based on the test parameters this adjustment (change). Here, the two different times include the case of the present and a past time, the case of a past time, and the case of a past time than this past time.

  According to the inspection apparatus of the present invention, it is possible to compare inspection images at two different times based on desired inspection parameters stored in the inspection parameter storage means. For this reason, it can be judged whether the inspection result based on the inspection parameter is normal. Further, if the inspection result is normal, the parameter criterion (setting value serving as a threshold value for determining a defect) in this inspection parameter is optimal. On the other hand, if the inspection result is not normal, the parameter criterion in the inspection parameter is not optimal. For this reason, it is possible to determine again whether or not the inspection result is normal with the changed inspection parameter by adjusting (changing) the parameter reference in the inspection parameter. As a result, it is possible to pursue the inspection parameters that are optimum for the part to be inspected (for example, a pad) to be inspected, and the inspection parameters can be set.

  That is, in the inspection apparatus of the present invention, it is possible to easily confirm the range of influence on the inspection result by changing the inspection parameter and the change point of the result. In addition, the inspection result and the parameter value associated with the inspection result can also be stored, whereby the inspection parameter having a difference in value can be specified. Also, the inspection parameter can be arbitrarily changed (adjusted), and the changed inspection parameter can be returned to the parameter reference of the original inspection parameter. Further, the image display means has first and second inspection image display sections for displaying inspection images at two different times for different parts to be inspected, and the images of these display sections can be easily compared. .

  The image storage means can store an inspection image. By setting in this way, the number of inspection image data can be increased, and the inspection accuracy can be improved.

  Further, the difference between the inspection image of the first inspection image display unit and the inspection image of the second inspection image display unit of the inspection target part is determined by using the inspection image and / or the second inspection image display unit of the first inspection image display unit. It can be set so as to be identified and displayed on the inspection image. By configuring in this way, it is possible to improve the confirmability of different places.

  It is preferable that the different part is displayed in a color different from that of the other part, and the display of the different part is facilitated to confirm the different part. Moreover, a difference location may be shown by the coordinate position on a workpiece | work. As described above, if the coordinate position is used, the defect position can be identified stably.

  The inspection method of the present invention is an inspection method for inspecting a defect of a part to be inspected based on an image of a part to be inspected of a workpiece, and displays inspection images at two different times of the part to be inspected. Using the image display means having the first and second inspection image display units, the inspection images at two different times based on the inspection parameters are displayed on the first and second inspection image display units, respectively. The inspection images are compared to determine whether or not the inspection result is normal. If the inspection result is not normal, the inspection parameters are adjusted, and the inspection images at two different times based on the adjusted inspection parameters are sequentially obtained. It is something to compare.

  The inspection method of the present invention can determine whether the inspection result based on the inspection parameter is normal. Further, if the inspection result is normal, the parameter criterion for this inspection parameter is optimum. On the other hand, if the inspection result is not normal, the parameter criterion in the inspection parameter is not optimal. For this reason, it is possible to determine again whether or not the inspection result is normal with the changed inspection parameter by changing the parameter reference in the inspection parameter. This makes it possible to set inspection parameters that are optimal for inspection with respect to the inspection target region (for example, pad) to be inspected.

  It can be determined whether or not the difference between the inspection images at two different times is a workpiece defect. That is, even if there is a difference, it may not be a defect of this work. In such a case, it can be determined that there is no defect. In order to determine that there is no defect, a determination criterion (threshold value) is set, and if this threshold value is exceeded, it is determined that there is no defect.

  If the difference is a workpiece defect, the process improvement of the manufacturing process, which is the previous process, can be performed. That is, by performing the process improvement in this manner, it is possible to effectively prevent the detected workpiece defect.

  In the present invention, it is possible to optimize the number of man-hours spent for checking the inspection parameters. It is possible to reduce the number of man-hours for combining the image inspection result, the image display unit, and the visual inspection result of the actual inspection target part. In addition, the outflow of defective products as good products can be prevented, and the deterioration of yield can be improved.

It is a simplified lineblock diagram of the inspection device of the present invention. It is a simplified block diagram of the inspection method of the present invention. It is a flowchart figure of the inspection method of this invention. It is a figure which shows a past image display part and a test | inspection image display part.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The inspection apparatus according to the present invention inspects whether or not the inspection target site S formed on the substrate 1 which is the workpiece W as shown in FIG. As described above, the image storage means 5 for storing the image in the inspection target part S and the inspection result on the image, the inspection parameter storage means 6 capable of storing a plurality of types of inspection parameters for the inspection target part S, An image pickup means 7 for picking up an image of the inspection target part S and an image display means 8 for displaying the inspection target part S imaged by the image pickup means 7 are provided. As shown in FIG. 4, the image display means 8 includes a monitor 8a having two screens for simultaneously displaying at least two different inspection images.

  Here, the two different times include a case of the present and a past time, a case of a past, and a case of a past than this past. For this reason, in this embodiment, one screen is a first inspection image display unit (past image display unit) 9 that displays a past inspection image of the inspection target region S, and the other screen is an inspection target. A second inspection image display unit (inspection image display unit) 10 that displays a current inspection image of the part S.

  The imaging means 7 includes an image recognition camera such as a CCD camera or a CMOS camera. Data picked up by the image pickup means 7 is input to the image storage means 5 and the control means 11. The control means 11 is, for example, a microcomputer in which a ROM (Read Only Memory), a RAM (Random Access Memory), and the like are connected to each other via a bus with a central processing unit (CPU) as a center. The image storage means (storage device) 5 and the inspection parameter storage means (storage device) 6 are respectively an HDD (Hard Disc Drive), a DVD (Digital Versatile Disk) drive, a CD-R (Compact Disc-Recordable) drive, an EEPROM ( Electronically Erasable and Programmable Read Only Memory). The ROM stores programs executed by the CPU and data.

  The image data of the image pickup means 7 is input to and stored in the storage means 5 and is input to the control means 11 and displayed on the inspection image display unit 10 of the image display means 8. The inspection image stored in the image storage unit 5 is displayed on the past image display unit 9 of the image display unit 8 as a past inspection image. The image storage means 5 also stores test results described later. For this reason, in addition to the inspection image, the monitor 8a may be provided with a screen for displaying inspection results (such as those obtained by digitizing defects), and further a screen for displaying inspection parameters. For this reason, the monitor 8a is not limited to having two screens, and may have a plurality of screens on two screens. Note that inspection parameters and inspection results may be displayed on the inspection image.

  The inspection parameter is a luminance rate for determining the presence / absence of a pad, an image binarization threshold value, and the like. If the image based on this inspection parameter, that is, the inspection parameter is a luminance rate for determining the presence / absence of a pad, If the threshold value for image binarization is set as the luminance rate for setting the inspection target region S, the inspection target region S is white if it is above the set threshold value, and is inspected if it is below the set threshold value The target part S is black.

  The control unit 11 includes a parameter changing unit 12 and a defect extracting unit 13. The parameter changing unit 12 can change (adjust) the parameter reference (threshold value or the like) of the inspection parameter stored in the inspection parameter storage unit 6. The defect extraction means 13 is a means for performing a defect extraction process 18 described later.

  Next, a method for inspecting whether or not the inspection target site S formed on the substrate 1 which is the workpiece W has the defective portion 3 by the detection apparatus configured as described above will be described with reference to FIGS. It explains using. In this case, an inspection parameter that is optimal for inspection is set for the inspection target site S to be inspected, and inspection is performed using the inspection parameter.

  As shown in FIG. 2, the inspection method (inspection method) includes an image acquisition step 15, an image / inspection result comparison step 16, an inspection parameter setting step 17, a defect extraction step 18, and the like. That is, as shown in FIG. 3, first, the inspection parameters are adjusted (step S1). Next, a past inspection image of the inspection target region S corresponding to the inspection parameter (an image stored in the inspection parameter storage means 6) is displayed on the past image display unit 9 and the object corresponding to the inspection parameter is displayed. An inspection image of the region to be inspected (inspection image currently being inspected) is displayed on the inspection image display unit 10 (step S2). In this case, image processing and adjustment are performed and displayed on the inspection image display unit 10. That is, the image acquisition process 15 shown in FIG. 2 is performed.

  Thereafter, the image displayed on the past image display unit 9 is compared with the image displayed on the inspection image display unit 10 (step S3). By this comparison, it is determined whether or not the inspection result is normal (step S4). The determination as to whether the inspection result is normal or not is made visually by the operator. That is, the image / inspection result comparison step 16 of FIG. 2 is performed. In this case, if the inspection result is normal, there is no difference between both images, and if the inspection result is not normal, there is a difference between both images. Here, when the inspection result is normal, when the inspection target part S does not have a defect for the inspection parameter in both images, and when the inspection target part S has the defect for the inspection parameter in both images There is. The storage means 5 stores an inspection image and an inspection result.

  If it is determined to be normal in step S4, the process proceeds to step S5 to determine whether or not there is a defect. If it is determined in step S4 that it is not normal, the process returns to step S1 to adjust the inspection parameters. Here, the adjustment of the inspection parameter is a change of a parameter standard (threshold value or the like), and the threshold value is increased or decreased. Note that the change of the inspection parameter includes a change of the inspection parameter itself (change of category). If it is determined to be normal in step S4, this inspection parameter has an optimum parameter criterion (for example, threshold value) in the inspection parameter.

  If it is determined in step S5 that there is a defect, the process proceeds to step S6 to determine whether this defect is a defect as a product. If it is determined in step S5 that there is no defect, the process proceeds to step S7. In this case, the inspection parameter has an optimum parameter criterion (for example, threshold) in the inspection parameter.

  For this reason, it is possible to set the inspection parameter that is optimal for the inspection with respect to the inspection target site S (for example, the pad 2) to be inspected, and the inspection parameter setting step 17 shown in FIG.

  If the product is defective in step S6, the process proceeds to step S7. If the product is not defective in step S6, the process returns to step S1. In step S7, it is determined whether or not to end this inspection. If it is to be ended, it is ended. If it is not to be ended, the process returns to step S1. In step S6, it is determined that the product is a defect, and the defect extraction step 18 shown in FIG. 2 ends. Thereafter, the inspection target site S of the workpiece W is inspected using inspection parameters that are optimal for inspection.

  When inspection is performed by the inspection apparatus according to the present invention, inspection images at two different times based on inspection parameters desired and adjusted from inspection parameters stored in the inspection parameter storage unit 6 can be compared. Therefore, it can be determined whether or not the inspection result based on the inspection parameter is normal. Further, if the inspection result is normal, the parameter criterion for this inspection parameter is optimum. On the other hand, if the inspection result is not normal, the parameter criterion in the inspection parameter is not optimal. Therefore, it is possible to determine again whether or not the inspection result is normal with the changed inspection parameter by changing (adjusting) the parameter reference in the inspection parameter. As a result, it is possible to pursue the inspection parameters that are optimal for the inspection with respect to the inspection target site S to be inspected.

  For this reason, it is possible to easily confirm the range of influence on the inspection result due to the change (adjustment) of the inspection parameter and the change point of the result. An inspection result and a parameter value associated with the inspection result can also be stored, so that an inspection parameter having a difference in value can be specified. Also, the inspection parameter can be arbitrarily changed (adjusted), and the changed inspection parameter can be returned to the parameter reference of the original inspection parameter. Moreover, the image display means 8 has an inspection image display section 10 that displays the current image of the part to be inspected, and a past image display section 9 that displays past images stored in the image storage means. Thus, the images on the display units 9 and 10 can be easily compared.

  Therefore, in the present inspection apparatus, as shown in the flowchart of FIG. 3, the number of man-hours spent for inspecting the inspection parameters can be optimized. The number of man-hours for combining the image inspection result and the visual inspection result can be reduced. In addition, the outflow of defective products as good products can be prevented, and the deterioration of yield can be improved.

  The image storage means 5 can store the current inspection image as a past inspection image in the region to be inspected. By setting in this way, the number of data of past inspection images can be increased, and inspection accuracy can be improved.

  Further, it is possible to set so that the difference between the current inspection image and the past inspection image of the region to be inspected is identified and displayed on the current inspection image and / or the past inspection image. In FIG. 4, the pad 2 having the defect 3 in both images is surrounded by a square frame as an identification display. For example, a color that is different from other parts on the screen is colored, or if the part around the different part is black, the different part can be made white. By configuring in this way, it is possible to improve the confirmability of different places.

  The difference portion is colored and displayed in a color different from other portions, so that the difference portion can be easily confirmed. In addition, a coordinate axis may be provided on the workpiece W, and a different portion may be represented on this coordinate axis. As described above, if the coordinate position is used, the defect position can be identified stably.

  It can be determined whether or not the difference between the current image of the part S to be inspected and the past image is a workpiece defect. That is, even if there is a difference, it may not be a defect of this work. In such a case, it can be determined that there is no defect. In order to determine that there is no defect, a determination criterion (threshold value) is set, and if this threshold value is not exceeded, it is determined that there is no defect.

  If the difference is a workpiece defect, the process improvement of the manufacturing process, which is the previous process, can be performed. That is, by performing the process improvement in this way, it is possible to effectively prevent the detected workpiece defect from occurring in the workpiece production process.

  The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, as past inspection images recorded in the image storage unit 5 and inspection parameters stored in the inspection parameter storage unit 6, It may be input to the control means 11 via a computer network. When the inspection parameter is changed (adjusted), the image can be re-inspected without taking a new image. The inspection target portion S of the workpiece W is not limited to the pad 2 of the substrate 1 and may be a circuit pattern or the like.

  When identifying and displaying a difference between the current inspection image and the past inspection image of the part S to be inspected, identification display on the current inspection image side, identification display on the past inspection image side, both image sides Can be identified and displayed. In addition, when comparing a past inspection image with a current inspection image, in the above-described embodiment, the inspection is performed by the operator's visual observation. Good.

  By the way, as said embodiment, the inspection image at two different times was the current inspection image and a certain past inspection image, but without using the current inspection image, the inspection image at a certain past time, The inspection image of the past may be used further than the past. Further, the inspection image is not limited to two different times, and inspection images at two or more different times may be displayed on the image display means 8. In FIG. 4, the first inspection image display unit is the past image display unit 9 and the second inspection image display unit is the inspection image display unit (current image display unit) 10. The display unit may be the inspection image display unit (current image display unit) 10 and the second inspection image display unit may be the past image display unit 9.

5 Image storage means 6 Inspection parameter storage means 7 Imaging means 8 Image display means 9 First image display section (past image display section)
10 Second image display unit (inspection image display unit)
S Part to be inspected W Work

An inspection apparatus of the present invention is an inspection apparatus that performs an inspection for comparing inspection images at two times in an inspection target part based on an image of the inspection target part of a workpiece, Imaging means for picking up an inspection image, image storage means for storing an inspection image at a part to be inspected, inspection parameter storage means for storing inspection parameters for the part to be inspected, and inspection stored in the inspection parameter storage means Parameter changing means for changing parameters, and image display means having first and second examination image display sections for respectively displaying examination images at two different times at different parts to be examined, and different two based on examination parameters The inspection images at the two times are displayed on the first and second inspection image display sections, and the inspection images at the two different times are compared, and the inspection result is normal Determine if the test result is not normal, to adjust the inspection parameters by the parameter changing means, and performs the inspection to compare the inspection image when the two different based on the test parameters this change.

The inspection method of the present invention is an inspection method for performing an inspection for comparing inspection images at two times in an inspection target part based on an image of the inspection target part of a workpiece, and the inspection target part is different in 2 The first and second inspection image display units display different two time inspection images based on desired inspection parameters using image display means having first and second inspection image display units for displaying the respective inspection images at one time. Each of the two different inspection images is compared, and it is determined whether or not the inspection result is normal. If the inspection result is not normal, the desired inspection parameter is adjusted and the adjusted inspection is performed. The inspection is performed by sequentially comparing inspection images at two different times based on the parameters.

Claims (8)

An inspection apparatus for inspecting a defect of an inspection target part based on an image of an inspection target part of a workpiece,
An imaging means for imaging an inspection image of a part to be inspected of the workpiece;
Image storage means for storing an inspection image in a region to be inspected;
Inspection parameter storage means for storing inspection parameters for a region to be inspected;
Parameter changing means for changing the inspection parameters stored in the inspection parameter storage means;
Image display means having first and second inspection image display units for respectively displaying inspection images at two different times of the region to be inspected,
Two different inspection images based on the inspection parameters are displayed on the first and second inspection image display units, respectively, and the two different inspection images are compared to determine whether the inspection result is normal, An inspection apparatus characterized in that, when an inspection result is not normal, an inspection parameter is adjusted by a parameter changing unit, and inspection images at two different times based on the changed inspection parameter are compared.   The inspection apparatus according to claim 1, wherein the image storage unit stores an inspection image in a region to be inspected.   The difference between the inspection image of the first inspection image display unit and the inspection image of the second inspection image display unit of the part to be inspected is determined by the inspection image of the first inspection image display unit and / or the inspection of the second inspection image display unit. The inspection apparatus according to claim 1, wherein the inspection apparatus performs identification display on an image.   The inspection apparatus according to claim 3, wherein the different portion is displayed in a color different from other portions.   The inspection apparatus according to claim 3, wherein the difference portion is indicated by a coordinate position on a workpiece. An inspection method for inspecting a defect of an inspection target part based on an image of an inspection target part of a workpiece,
Using image display means having first and second inspection image display units for respectively displaying inspection images at two different times of the region to be inspected, the first and second different inspection images based on desired inspection parameters are displayed. -Display on the second inspection image display unit, compare these two different inspection images, determine whether the inspection results are normal, and adjust the desired inspection parameters when the inspection results are not normal An inspection method comprising sequentially comparing inspection images at two different times based on the adjusted inspection parameter.   The inspection method according to claim 6, wherein it is determined whether or not a difference between two inspection images at different times is a workpiece defect.   The inspection method according to claim 7, wherein if the difference is a workpiece defect, process improvement of a manufacturing process which is a previous process is performed.

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