Foreign body detection device and method for foreign body detection

Abstract

A foreign matter detection device includes a detection section and a determination section. The detection section images at least a part of an inspection area of ​​a circuit board according to the progress of a predetermined circuit board processing by a circuit board processing machine configured to perform the circuit board processing on the circuit board, and acquires a plurality of image data obtained by imaging the same inspection area. The determination section determines the presence or absence of a foreign matter adhered to the inspection area based on a difference in the feature values ​​of the inspection area obtained by performing image processing on reference image data that is one piece of a plurality of pieces of image data and inspection image data that is image data of an inspection target acquired after the reference image data.In addition, the detection area acquires first image data, which is image data at a time when the board processing is interrupted by imaging the inspection area in a case where the board processing is interrupted during a period from the acquisition of the reference image data to the acquisition of the inspection image data.

Description

Technical FieldThe present specification discloses a technique related to a foreign matter detection device and a method for foreign matter detection.Prior ArtA mounting line described in Patent Literature 1 includes a first camera device, a second camera device, and an image processing device. The first camera device is a camera device capable of capturing at least a part of a circuit board in a field of view and configured to be capable of imaging the circuit board before mounting work of an electronic component in one of the mounting machines. The second camera device is a camera device capable of capturing a similar range to the first camera device in a field of view and provided so as to be capable of imaging the circuit board after an assembly work of the electronic component by one of the assembly machines or the assembly machine in a later process than the one assembly machine.The image processing device performs image processing by comparing image data captured by the second camera device with image data captured by the first camera device. Accordingly, the mounting line described in Patent Literature 1 detects a printing abnormality of the solder when the solder is printed on a circuit board or a mounting abnormality of an electronic component when the electronic component is mounted on the circuit board.List of the listed documentsPatent LiteraturePatent Literature 1: JP 2007-335524 ASUMMARY OF THE INVENTIONTechnical ProblemWhen a foreign object is attached to a mounting position of a component, the mounting of the component may become defective, and it is necessary to detect the presence or absence of the foreign object attached to the board. In this case, it is assumed that a plurality of image data obtained by imaging the same inspection region of at least a part of the board are compared with each other, and the presence or absence of the foreign matter is determined based on a difference in the feature values of the image data.However, there is a possibility that work on a board is interrupted by a board processing machine in a period between the time of acquiring the reference image data and the time of acquiring the image data to be compared with the reference image data. When the state in which the board processing is interrupted continues, the state of the board may change, and there is a need to detect the state of the board at a time when the board processing is interrupted.In view of such circumstances, in the present specification, a foreign matter detection device and a method for foreign matter detection capable of acquiring image data at the time when work on a board is interrupted are disclosed.Solution of the ProblemThe present specification discloses a foreign matter detection device including a detection section and a determination section. The acquisition section images at least a part of an inspection area of a board according to the progress of predetermined board processing by a board processing machine configured to perform the board processing on the board, and acquires a plurality of image data obtained by imaging the same inspection area. The determination section determines the presence or absence of a foreign matter adhering to the inspection area based on a difference in the feature values of the inspection area acquired by performing image processing on reference image data that is a part of a plurality of pieces of image data and inspection image data that is image data of an inspection target acquired after the reference image data. Moreover, the acquisition section acquires first image data which is image data at a time when the work on the board is interrupted, i.e., when the work on the board is interrupted during a period from the acquisition of the reference image data to the acquisition of the inspection image data.The present specification also discloses a method for foreign matter detection including a detection step and a determination step. In the acquiring step, at least a part of an inspection area of a board according to the progress of predetermined board processing is imaged by a board processing machine configured to perform the board processing on the board, and a plurality of pieces of image data obtained by imaging the same inspection area are acquired. In the determination step, the presence or absence of a foreign matter adhering to the inspection region is determined based on a difference in feature values of the inspection region acquired by image processing of reference image data that is a part of a plurality of pieces of image data and inspection image data that is image data of an inspection target acquired after the reference image data. In addition, in the acquiring step, first image data that is image data at a time when the work on the board is interrupted by imaging the inspection area is acquired in a case where the work on the board is interrupted during a period from acquisition of the reference image data to acquisition of the inspection image data.Note that the present specification discloses a technical idea in which the "foreign matter detection device according to claim 1" in claim 6 described in claims originally attached to the application (hereinafter referred to as original claims) is changed to the "foreign matter detection device according to any one of claims 1 to 5". Moreover, the present specification discloses a technical idea in which the "foreign matter detection device according to claim 1" in claim 9 described in the original claims is changed to the "foreign matter detection device according to any one of claims 1 to 8". Moreover, the present specification discloses a technical idea in which the "foreign matter detection device according to claim 1" in claim 11 described in the original claims is changed to the "foreign matter detection device according to any one of claims 1 to 10". Moreover, the present specification discloses a technical idea in which the "foreign matter detection device according to claim 1" in claim 12 described in the original claims is changed to the "foreign matter detection device according to any one of claims 1 to 10". Moreover, the present specification discloses a technical idea in which the "foreign matter detection device according to claim 1" in claim 13 described in the original claims is changed to the "foreign matter detection device according to any one of claims 1 to 10 and 12".Advantageous Effects of the InventionWith the foreign matter detection device, it is possible to acquire the first image data, i.e., the image data at the time when the work on the board is interrupted. The above description of the foreign matter detection device can be similarly applied to the method for foreign matter detection.Brief Description of the DrawingsFIG. 1 is a schematic diagram showing a configuration example of a board production line. FIG. 2 is a plan view showing a configuration example of a component assembler. FIG. 3 is a block diagram showing an example of a control block of a foreign matter detection device. FIG. 4 is a flowchart showing an example of a control operation by the foreign matter detection device. FIG. 5 is a schematic diagram showing an example of reference image data. FIG. 6 is a schematic diagram showing an example of inspection image data. FIG. 7 is a schematic diagram showing an example of the state of a board until the work on the board is interrupted. FIG. 8 is a schematic diagram showing an example of the state of the board after work is resumed on the board.DESCRIPTION OF THE EMBODIMENTS1. Exemplary Embodiment1-1. Configuration Example of Board Production Line WL 0In the board production line WL 0, the board processing machine WM 0 performs predetermined board processes on the board 90. The type and number of the board processing machines WM 0 constituting the board production line WL 0 are not limited. As illustrated in FIG. 1, the board production line WL 0 of the embodiment includes a plurality of board processing machines WM 0, namely, the printer WM 1, the printing inspector WM 2, the component assembler WM 3, the reflow oven WM 4, and the self-inspection inspector WM 5, and the board 90 is transported by a board supply device in the order described above in an embodiment.The printer WM 1 prints solder on the mounting positions of a plurality of components 91 of the board 90. the printing inspector WM 2 checks the printing state of the solder printed by the printer WM 1. As illustrated in FIG. 2, the component assembler WM 3 mounts a plurality of components 91 on the board 90 on which the printer WM 1 has printed solder. One or more component mounting devices WM 3 can be provided. When multiple component mounters WM 3 are provided, multiple component mounters WM 3 may be used in common to mount multiple components 91.The reflow furnace WM 4 heats the board 90 on which a plurality of components 91 are mounted by the component assembler WM 3, melts the solder, and performs the soldering. The perspective inspector WM 5 checks the mounting state or the like of a plurality of components 91 mounted by the component assembler WM 3. In this way, the board production line WL 0 can sequentially transport the board 90 using a plurality of board processing machines WM 0 and perform a production process including an inspection process so as to produce the board product 900. Note that the board production line WL 0 may include the board processing machine WM 0, such as a function tester, a buffer device, a board feeding device, a board reversing device, a screen mounting device, an adhesive applying device, and an ultraviolet irradiation device, as needed.A plurality of board processing machines WM 0 constituting the board production line WL 0 and the line management device LC 0 are connected to each other so as to be capable of communicating with each other via a communication section. The line management device LC 0 and the management device HC 0 are also connected to each other so as to be able to communicate with each other via the communication section. The communication section may connect the line management device LC 0 and the management device HC 0 to each other via wired or wireless communication, and there are various methods for the communication.In the embodiment, a local area network (LAN) is configured with a plurality of board processing machines WM 0, a line management device LC 0, and a management device HC 0. Thus, a plurality of board processing machines WM 0 can communicate with each other via the communication section. In addition, a plurality of board processing machines WM 0 may communicate with the line management device LC 0 via the communication portion. In addition, the line management device LC 0 and the management device HC 0 may communicate with each other via the communication section.The line management device LC 0 controls a plurality of board processing machines WM 0 constituting the board production line WL 0, and monitors the operation state of the board production line WL 0. The management device LC 0 stores various control data for controlling a plurality of board processing machines WM 0. The management device LC 0 transmits the control data to each of the plurality of board processing machines WM 0. Moreover, each of the plurality of board processing machines WM 0 transmits an operation and production status to the management device LC 0.The management device HC 0 manages at least one line management device LC 0. For example, the operation status and the production status of the board processing machine WM 0 acquired by the line management device LC 0 are transmitted to the management device HC 0 as needed. In the management device HC 0, a storage device is provided. In the storage device, various kinds of data acquired from the board processing machine WM 0 may be stored. The acquired data includes, for example, various image data captured by the board processing machine WM 0. The record (log data) of the operation status acquired by the board processing machine WM 0 includes the acquired data. Moreover, the storage device may store various production information related to the production of the board product 900.The board production line WL 0 includes the input / output device 80. The input / output device 80 includes a display portion that visually displays various data. The display area is equipped with a touch panel and also serves as an input device for various operations by a worker.1-2. Configuration Example of Component Assembler WM 3The component assembler WM 3 mounts a plurality of components 91 on the board 90.The board conveying device 11 includes, for example, a conveyor belt and the like, and conveys the board 90 in a conveying direction (X-axis direction). The circuit board 90 is a circuit board on which an electronic circuit, an electric circuit, a magnetic circuit, and the like are formed. The board conveying device 11 conveys the board 90 into the component assembler WM 3 and positions the component 90 at a predetermined location in the component assembler WM 3. After completion of the mounting operation of a plurality of components 91 by the component assembler WM 3, the board conveying device 11 unloads the board 90 from the component assembler WM 3.The component supply device 12 supplies a plurality of components 91 to be mounted on the board 90. The component feeding device 12 includes a plurality of feeds 12 aarranged along the conveyance direction (X-axis direction) of the board 90. Each of the plurality of leads 12a is provided with a spool. A carrier tape is wound around the reel, which holds a plurality of components 91. The feeder 12 afeedings the carrier tape pitch by pitch to feed the components 91, so that the components 91 can be accommodated at a feeding position located at a distal end side of the feeder 12 a. Moreover, the component supply device 12 can also supply a relatively large electronic component (e.g., a wiring component or the like) as compared with a chip component or the like placed on a tray.The component transfer device 13 includes a head driving device 13 aand a movable table 13 b. The head driving device 13 ais configured to move the movable table 13 bin the X-axis direction and the Y-axis direction (a direction orthogonal to that in a horizontal plane) by a linear movement mechanism. The mounting head 20 is detachable (replaceable) from the movable table 13 bby a clamp member. The mounting head 20 receives the component 91 supplied from the component supply device 12, holds it by means of at least one holding member 30, and mounts the component 91 on the board 90 positioned by the component supply device 11.As the parts camera 14 and the board camera 15, a known imaging device can be used. The division camera 14 is attached to a base of the component assembler WM 3 such that its optical axis is directed upward in the vertical direction (a Z-axis direction orthogonal to the X-axis direction and the Y-axis direction). Part camera 14 can capture an image of component 91 held by holding member 30 from below. The board camera 15 is mounted on the movable table 13 bof the component transfer device 13 such that an optical axis is directed downward in the vertical direction (Z-axis direction). The board camera 15 can image the board 90 from above. The parts camera 14 and the board camera 15 perform image capturing based on a control signal transmitted from the control device 16. The image data of the image captured by the sub camera 14 and the board camera 15 is transmitted to the control device 16.The control device 16 includes a known computing device and a storage device that constitute a control circuit. The information, image data, and the like output from various sensors in the component assembler WM 3 are input to the control device 16. The control device 16 transmits control signals to each device based on a control program, a mounting condition set in advance, and the like.For example, the control device 16 causes the board camera 15 to image the board 90 transported by the board transport device 11. The control device 16 performs image processing of the image captured by the board camera 15 to recognize a positioning state of the board 90. Moreover, the control device 16 causes the holding member 30 to pick up and hold the component 91 supplied from the component supply device 12, and causes the part camera 14 to image the component 91 held by the holding member 30. The control device 16 performs image processing of the image captured by the division camera 14 to recognize a holding position of the component 91.The control device 16 moves the holding member 30 toward above a scheduled mounting position set in advance by a control program or the like. Further, based on the positioning state of the board 90, the holding posture of the component 91, and the like, the controller 16 corrects the mounting posture that is scheduled to set the mounting position at which the component 91 is actually mounted. The planned mounting position and the mounting position also include a rotation angle in addition to the position (X-axis coordinate and Y-axis coordinate).The control device 16 corrects a target position (the X-axis coordinate and the Y-axis coordinate) of the holding member 30 and the rotation angle according to the mounting position. The control device 16 lowers the holding member 30 by the corrected rotation angle at the corrected target position to mount the component 91 on the board 90. The control device 16 repeats the above-described pick-and-place cycle to perform the mounting process of a plurality of components 91 on the board 90.1-3. Configuration Example of Foreign Matter Detection Device 70As illustrated in FIG. 2, when a foreign matter 92 (e.g., another component 91, dust, or the like) adheres to the mounting position of the component 91, mismounting of the component 91 may occur (e.g., nonmounting, floating, tilting, or the like of the component 91), and therefore it is necessary to detect the presence or absence of foreign matter 92 adhering to the board 90. In this case, it is assumed that a plurality of image data PD 0 obtained by capturing the same inspection area CA 0 of at least a part of the board 90 are compared, and the presence or absence of foreign matter 92 is determined based on a difference in the feature values (e.g., luminance of a pixel) of the image data PD 0.However, there is a possibility that the work on the board is interrupted by the board processing machine WM 0 during a period ranging from the acquisition of the image data PD 0 serving as a reference to the acquisition of the image data PD 0 to be compared with the image data PD 0 serving as a reference. When the state in which the board processing is interrupted continues, the state of the board 90 may change, and there is a requirement to grasp the state of the board 90 at the time when the board processing is interrupted. Therefore, the board production line WL 0 of the embodiment is provided with a foreign matter detection device 70 capable of acquiring image data at the time when the board processing is interrupted.The foreign matter detection device 70 includes, when regarded as a control block, a detection section 71 and a determination section 72. The foreign matter detection device 70 may include a guide portion 74. As illustrated in FIG. 3, the foreign matter detection device 70 of the embodiment includes the detection section 71, the determination section 72, the estimation section 73, and the guidance section 74.The foreign matter detection device 70 may be provided in various control devices. For example, the foreign matter detection device 70 may be provided in the control device 16 of the component assembler WM 3, the line management device LC 0, the management device HC 0, or the like. The foreign matter detection device 70 may be formed on a cloud. As illustrated in FIG. 3, in the foreign matter detection device 70 of the embodiment, a detection section 71, a determination section 72, an estimation section 73, and a guidance section 74 are provided in the control device 16 of the component assembler WM 3.The foreign matter detection device 70 of the embodiment executes the control according to the flowchart illustrated in FIG. 4. The detection section 71 performs the processing illustrated in step S 11, step S 12, step S 16, and step S 17. The determination section 72 performs a part of step S 13 and the processing illustrated in step S 18. The estimation section 73 executes a part of the processing of step S 13. The guide portion 74 performs the processing illustrated in step S 14, step S 15, step S 19, and step S 20.1-3-1. Example of Control when Board Processing is Normally PerformedThe acquisition section 71 images at least a part of the inspection area CA 0 of the board 90 together with the progress of board processing by the board processing machine WM 0 performing predetermined board processing on the board 90, and acquires a plurality of image data PD 0 obtained by imaging the same inspection area CA 0.The detection portion 71 may image the entire mounting area of the board 90 as the inspection area CA 0 or image a part of the mounting area of the board 90. In imaging a part of the mounting area of the circuit board 90, for example, the detection portion 71 may image a mounting area of a component 91 (e.g., a ball grid array (BGA) component 91 or the like) that has a larger number of electrodes than chip components and is easily affected by foreign matter 92. Moreover, the detection section 71 can also detect a mounting area where a mounting error of the component 91 due to foreign matters 92 has occurred, a mounting area where foreign matters 92 are likely to adhere, and the like, based on the past mounting records, and image the mounting areas as the inspection area CA 0.The detection portion 71 may set an area referred to as an inspection area CA 0 by a worker of the component assembler WM 3 mounting the component 91 on the board 90. The board production line WL 0 includes the input / output device 80 in the embodiment. for example, the worker may designate an arbitrary area (the entire mounting area of the board 90 or a part of the mounting area of the board 90) as the inspection area CA 0 by using the input / output device 80. In this case, the detection section 71 may cause the display section of the input / output device 80 to schematically display the mounting area of the component 91 on the board 90, and the worker may select an arbitrary mounting area.The acquisition section 71 may acquire image data PD 0 with an imaging device capable of imaging the inspection area CA 0. The imaging device only needs to image the inspection area CA 0 and is not limited to a specific area. The imaging device includes, for example, a board camera 15 capable of imaging a part of the mounting range of the board 90 from above the board 90, a ceiling camera capable of imaging the entire mounting range of the board 90 from above the board 90, and the like. In the embodiment, the board camera 15 is used, and the detection section 71 sets an area designated as a inspection area CA 0 by the worker of the component assembler WM 3. The acquisition section 71 acquires a plurality of image data PD 0 by imaging the same inspection range CA 0 a plurality of times under the same imaging conditions (e.g., exposure time, aperture, illumination time, and the like) that are adjustable by the imaging device.The determination section 72 determines the presence or absence of foreign matter 92 adhering to the inspection area CA 0 based on the difference of the feature values of the inspection area CA 0 acquired by performing the image processing on reference image data SD 0 and inspection image data CD 0. Reference image data SD 0 refers to image data PD 0 among a plurality of image data PD 0 acquired by acquisition section 71. Inspection image data CD 0 refers to image data PD 0 of the inspection target acquired from acquisition section 71 after reference image data SD 0.The determination section 72 only needs to determine the presence or absence of foreign matter 92 in the inspection area CA 0 based on the difference of the feature values of the inspection area CA 0, and may take various forms. For example, the determination section 72 determines that foreign matter 92 is present in the inspection area CA 0 when the difference between the feature values of the inspection area CA 0 acquired from the two image data PD 0 (in this case, reference image data SD 0 and inspection image data CD 0) exceeds a predetermined threshold value. When the difference between the feature values is equal to or less than the predetermined threshold, the determination section 72 determines that no foreign matter 92 is present in the inspection area CA 0.The feature value only needs to be obtained by image processing of the image data PD 0, and is not limited to a specific value. The feature value includes luminance, saturation, brightness, and the like of each pixel of the two image data pieces PD 0 (reference image data SD 0 and inspection image data CD 0). The closed area region and the length of the outer periphery of the closed area acquired by image processing (e.g., binarization) on each of the two pieces of image data PD 0 (reference image data SD 0 and inspection image data CD 0) are included in the feature value. In the embodiment, the feature value is the luminance of each pixel of the two image data pieces PD 0 (reference image data SD 0 and inspection image data CD 0).The predetermined threshold value is set to be larger than the feature value (e.g., luminance of a pixel) when no foreign matter 92 adheres in the inspection area CA 0 and smaller than the feature value when a foreign matter 92 adheres in the inspection area CA 0. The predetermined threshold is determined in advance, for example, by simulation, inspection with an actual machine, or the like.FIGS. 5 and 6 schematically show an example of a plurality of (two) pieces of image data PD 0 acquired by the acquisition section 71. FIG. 5 shows the reference image data SD 0, and FIG. 6 shows the inspection image data CD 0. For the sake of simplicity, several pixels arranged in the form of a grid are shown together in FIGS. 5 and 6. The area AR 0 illustrated in FIGS. 5 and 6 denotes the same area (a group of a plurality of the same pixels) in the inspection area CA 0.When foreign matter 92 is present in the area AR 0, the difference between the luminance of the pixels included in the area AR 0 illustrated in FIG. 5 and the luminance of the pixels included in the area AR 0 illustrated in FIG. 6 exceeds the predetermined threshold. Conversely, when no foreign matter is present in area AR 0, the difference between the luminance of the pixels included in area AR 0 as illustrated in FIG. 5 and the luminance of the pixels included in area AR 0 as illustrated in FIG. 6 is equal to or less than the predetermined threshold.Accordingly, the determination section 72 determines that foreign matters 92 are present in the inspection area CA 0 when the difference between the luminance of the pixels included in the area AR 0 illustrated in FIG. 5 and the luminance of the pixels included in the area AR 0 illustrated in FIG. 6 exceeds the predetermined threshold. When the difference between the luminance of the pixels included in the area AR 0 illustrated in FIG. 5 and the luminance of the pixels included in the area AR 0 illustrated in FIG. 6 is equal to or less than the predetermined threshold, the determination section 72 determines that no foreign matter 92 is present in the inspection area CA 0. The luminance is compared for each corresponding pixel.The acquisition section 71 may acquire reference image data SD 0 and inspection image data CD 0 at a predetermined timing. As illustrated in FIG. 1, the board 90 is transported to a plurality (three in FIG. 1 ) of component mounters WM 3 which is the board processing machine WM 0 in order, and a plurality of components 91 are mounted on the board 90. For convenience of description, the component assembler WM 3 on the most upstream side among a plurality of (three) component assemblers WM 3 will be referred to as a component assembler M 1. Further, the next component assembler WM 3 on the downstream side of the component assembler M 1 is referred to as a component assembler M 2. Further, the next component assembler WM 3 on the downstream side of the component assembler M 2 is referred to as a component assembler M 3.In the board production line WL 0 described above, for example, the acquisition section 71 acquires reference image data SD 0 in the component assembler WM 3 (component assembler M 1) on the upstream side of a plurality of (three) component assemblers WM 3. More specifically, the acquisition section 71 images the inspection area CA 0 to acquire reference image data SD 0 before the mounting process of component 91 in the component assembler M 1 starts.Moreover, the acquisition section 71 acquires inspection image data CD 0 in the component assembler WM 3 (e.g., component assembler M 3) that mounts the component 91 in the inspection area CA 0. More specifically, the acquisition section 71 acquires inspection image data CD 0 by imaging the inspection area CA 0 before mounting the component 91 in the inspection area CA 0 in the component assembler M 3. In this case, the determination section 72 may determine the presence or absence of foreign matter 92 adhering in the inspection area CA 0 while the board 90 is being transported across a plurality (three) of component mounters WM 3. In the present specification, the above-described embodiment will be referred to as a first embodiment.The acquisition section 71 may also acquire reference image data SD 0 and inspection image data CD 0 in each of the plurality (three) of component mounters WM 3. In at least one component assembler WM 3 (component assembler M 1 and component assembler M 2) provided on the upstream side of the component assembler WM 3 (e.g., component assembler M 3) that assembles the component 91 in the inspection area CA 0, the acquisition section 71 acquires the reference image data SD 0 by imaging the inspection area CA 0 before the assembly operation of the component 91 is started. In each of the component mounters WM 3 (component mounter M 1 and component mounter M 2), after completion of the mounting process of component 91, the acquisition section 71 acquires inspection image data CD 0 by imaging the inspection area CA 0.Moreover, in the component assembler WM 3 (e.g., component assembler M 3) that mounts the component 91 in the inspection area CA 0, reference image data SD 0 is acquired in the acquisition section 71 by imaging the inspection area CA 0 before the mounting process of the component 91 starts. In the component assembler WM 3 (component assembler M 3), the acquisition section 71 acquires the inspection area CA 0 to acquire inspection image data CD 0 before the component 91 is mounted in the inspection area CA 0. In this case, the determination section 72 may determine the presence or absence of foreign matter 92 in the inspection area CA 0 in each of a plurality of (three) component mounters WM 3. In the present specification, the above-described embodiment will be referred to as a second embodiment.The acquisition section 71 may also acquire reference image data SD 0 and inspection image data CD 0 between the adjacent component mounters WM 3. The acquisition section 71 acquires the reference image data SD 0 in a component assembler WM 3 among a plurality (three) of component assemblers WM 3. More specifically, the acquisition section 71 acquires the reference image data SD 0 by imaging the inspection area CA 0 after the mounting operation of the component 91 in the component assembler WM 3 is completed and before the board 90 is unloaded.Moreover, the acquisition section 71 acquires inspection image data CD 0 in the next component assembler WM 3 on the downstream side of the component assembler WM 3. More specifically, the acquisition section 71 acquires the inspection image data CD 0 by imaging the inspection area CA 0 after the board 90 is inserted into the component mounter WM 3 and before the mounting process of the component 91 into the component mounter WM 3 starts. In this case, the determination section 72 may determine the presence or absence of foreign matter 92 located in the inspection area CA 0 when the board 90 is transported between the adjacent component mounters WM 3. In the present specification, the above-described embodiment will be referred to as a third embodiment.1-3-2. Example of Control when Board Processing is InterruptedFor example, when the result of the image processing of the image data PD 0 acquired from the imaging device (in the component assembler WM 3, for example, the part camera 14, the board camera, or the like) is defective, the board processing machine WM 0 may interrupt the work on the board. Moreover, the board processing machine WM 0 may stop board processing when a situation occurs in which board processing cannot be continued (e.g., in the component assembler WM 3 when the component 91 to be mounted is missing). In addition, the worker may operate a stop button to interrupt board machining by the board machining machine WM 0.The acquisition section 71 acquires first image data PD 1 by imaging the inspection area CA 0 when board processing is interrupted during the period between the acquisition of reference image data SD 0 and the acquisition of inspection image data CD 0 (YES in step S 11 and step S 12 in FIG. 4 ). The first image data PD 1 is the image data PD 0 at the time when the board processing is interrupted. The acquisition section 71 can acquire the first image data PD 1 by imaging the inspection area CA 0 at the time when the board processing is interrupted, as in the case where the board processing is normally performed. Accordingly, the foreign matter detection device 70 can acquire image data PD 0 at the time when the board processing is interrupted, and can acquire the state of the board 90 at the time when the board processing is interrupted.Moreover, the determination section 72 may determine the presence or absence of foreign matter 92 on the basis of the difference of the feature values of the inspection area CA 0 acquired by performing image processing of reference image data SD 0 and first image data PD 1 (step S 13 illustrated in FIG. 4 ). The determination section 72 may determine the presence or absence of foreign matter 92 as in the case where the board processing is normally performed.Specifically, the determination section 72 determines that foreign matter 92 is present in the inspection area CA 0 when the difference between the feature values of the inspection area CA 0 obtained from two image data PD 0 (in this case, reference image data SD 0 and first image data PD 1) exceeds a predetermined threshold value. When the difference between the feature values is equal to or less than the predetermined threshold, the determination section 72 determines that no foreign matter 92 is present in the inspection area CA 0. As described above, the feature value is not limited. In the embodiment, the feature value is the luminance of each pixel of two image data PD 0 (reference image data SD 0 and first image data PD 1).FIG. 7 shows an example of a state of the board 90 until work on the board is interrupted. In FIG. 7, a state of the board 90 until the completion of board processing in the component mounter M 2 is schematically illustrated using image data PD 0, the first embodiment being taken as an example. Specifically, in the component assembler M 1 on the upstream side, the acquisition section 71 acquires reference image data SD 0 among a plurality of (three) component assemblers WM 3.Then, it is assumed that the board 90 is transported to the next component assembler M 2 on the downstream side of the component assembler M 1, and board processing in the component assembler M 2 is interrupted. The acquisition section 71 acquires the inspection area CA 0 to acquire the first image data PD 1 at the time when the board machining is interrupted in the component assembler M 2 in which the board machining is interrupted. In the reference image data SD 0 and the first image data PD 1 illustrated in FIG. 7, the difference in the feature values of the inspection area CA 0 is small (the difference in the feature values is equal to or less than the predetermined threshold value), and the determination section 72 determines that no foreign matter 92 is present in the inspection area CA 0. In FIG. 7, the board 90 is not yet transported to the next component assembler M 3 on the downstream side of the component assembler M 2, and the image data PD 0 is displayed by a space.As described above, the determination section 72 may determine the presence or absence of foreign matter 92 when the first image data PD 1 is acquired by the acquisition section 71. Accordingly, the determination section 72 can determine the presence or absence of foreign matter 92 in the inspection area CA 0 during a period from the acquisition of the reference image data SD 0 by the acquisition section 71 to the completion of board processing. As described below, the determination section 72 may also determine the presence or absence of foreign matter 92 when a predetermined condition is satisfied. For example, there is a possibility that the feature value of the inspection area CA 0 acquired by performing the image processing of the image data PD 0 is changed by the temporal change of the connector 93 that is applied to the inspection area CA 0 of the board 90 and connects the board 90 and the component 91.The connection member 93 only needs to connect the circuit board 90 and the component 91, and is not limited to a specific member. The connection member 93 includes, for example, solder, an adhesive, or the like. In the embodiment, the connecting member 93 is made of solder. The solder changes color from silver to gray as the flux contained dries. Therefore, there is a possibility that the feature value of the inspection area CA 0 changes due to the temporal change of the solder, and the determination section 72 erroneously determines the solder as the foreign matter 92.Here, a time from the time point at which the board processing is interrupted to the time point at which the board processing is resumed is referred to as a stop time Q 0. In addition, the stop time Q 0 in which the connector 93 is not erroneously determined as the foreign matter 92 even when the feature value of the inspection area CA 0 is changed due to the temporal change of the connector 93 applied to the inspection area CA 0 and connecting the board 90 and the component 91 is set as the allowable time T 0. Since the stop time Q 0 becomes shorter than the allowable time T 0, in the determination of the presence or absence of foreign matter 92 in the component assembler M 3, it is less likely to be affected by the temporal change of the connection member 93, and the necessity of the determination of the presence or absence of foreign matter 92 in the component assembler M 2 in which the board processing is interrupted decreases.Conversely, when the stop time Q 0 is longer than the allowable time T 0, the determination of the presence or absence of foreign matter 92 in the component assembler M 3 is likely to be affected by the change over time of the connector 93, and the determination section 72 is likely to erroneously determine the connector 93 as the foreign matter 92. Then, the estimation section 73 estimates the stop time Q 0 from the time point at which the board machining is interrupted to the time point at which the board machining is resumed (step S 13 illustrated in FIG. 4 ).The estimation section 73 only needs to estimate the stop time Q 0 and may take various forms. For example, the estimation section 73 may estimate the stop time Q 0 based on a cause (e.g., the result of image processing of image data PD 0 is erroneous) that board processing is stopped. In this case, at each production of the board product 900, the estimation section 73 stores in advance the cause of the board processing interruption and the stop time Q 0 from the time point at which the board processing is interrupted to the time point at which the board processing is resumed in association with each other. The stop time Q 0 may be represented by an average value or a median value, for example.When the board machining is interrupted in the current production of the board product 900, the estimation section 73 outputs the stop time Q 0 (e.g., an average value or a median value) stored in association with the cause for the interruption of the board machining to the determination section 72. When the estimation section 73 estimates the stop time Q 0 longer than the allowable time T 0, the determination section 72 may determine the presence or absence of foreign matter 92 (step S 13 illustrated in FIG. 4 ).Moreover, for example, in a case where the worker takes measures when board machining is interrupted, the actual stop time Q 0 may be longer than the stop time Q 0 estimated by the estimation section 73. Accordingly, the determination section 72 can also determine the presence or absence of foreign matter 92 when the stop time Q 0 is longer than the allowable time T 0 estimated after the stop time Q 0 within the allowable time T 0 by the estimation section 73.The allowable time T 0 may be determined in advance, for example, by simulation, inspection with a current machine, or the like. The allowable time T 0 may vary depending on the type of the connector 93, and the determination section 72 may use the allowable time T 0 depending on the type of the connector 93. For example, the determination section 72 may use the allowable time T 0 according to the type of the solder. The determination section 72 may use the allowable time T 0 according to the type of the adhesive.Further, as the temperature in the component mounter WM 3 rises, the flux contained in the solder is likely to be dried more quickly. In addition, the flux contained in the solder is likely to be dried more quickly when the humidity in the component mounter WM 3 decreases. Accordingly, the determination section 72 may use the allowable time T 0 corresponding to at least one of the temperature and the humidity in the component mounter WM 3 mounting the component 91 on the board 90.When the determination section 72 determines that foreign matters 92 are present in the inspection area CA 0, the guidance section 74 gives the worker an indication of the presence of foreign matters 92 (Yes in steps S 14 and S 15 illustrated in FIG. 4 ). The guide portion 74 only needs to give the worker an indication of the presence of foreign matter 92, and may have various shapes. For example, in the embodiment, the board production line WL 0 includes the input / output device 80. The guide portion 74 may give the worker an indication of the presence of foreign matter 92 (e.g., through a display, an acoustic guidance, or the like) via the input / output device 80.Specifically, the guide portion 74 may give an indication of the presence of the board 90 to which foreign matters 92 adhere, the position of a part on the board 90 to which foreign matters 92 adhere, the board processing machine WM 0 in which the board 90 is located, and the like. Accordingly, the worker can check the board 90 to which foreign matter 92 adheres and take measures (e.g., unloading the board 90). The guide portion 74 may similarly give an indication (e.g., display, acoustic guidance, vibration, or the like) of the presence of foreign matter 92 to the worker by using a mobile terminal belonging to the worker.When the board processing is resumed, the acquisition section 71 acquires the second image data PD 2 by imaging the inspection area CA 0, and updates the reference image data SD 0 based on the second image data PD 2 (YES in step S 16 and step S 17 in FIG. 4 ). The second image data PD 2 is the image data PD 0 at the time when the work on the board is resumed. The acquisition section 71 can acquire the second image data PD 2 by imaging the inspection area CA 0 at the time when the work on the board is resumed, as in the case where the board work is normally performed. Accordingly, the foreign matter detection device 70 can acquire the image data PD 0 at the time when the work on the board is resumed.As described above, in a case where the stop time Q 0 from the time when the board machining is interrupted to the time when the work on the board is resumed is longer than the allowable time T 0, the determination of the presence or absence of foreign matter 92 in the component assembler M 3 is likely to be affected by the change over time of the connector 93, and the determination section 72 is likely to erroneously determine that the connector 93 is a foreign matter 92. Therefore, the acquisition section 71 can update the reference image data SD 0 with the second image data PD 2 when the stop time Q 0 is longer than the allowable time T 0.Moreover, the connector 93 changes over time even when the stop time Q 0 between the interruption of board machining and the resumption of board machining is within the allowable time T 0. Therefore, regardless of the suspension time Q 0 at the resumption of board processing, the acquisition section 71 can acquire second image data PD 2 by imaging the inspection area CA 0 and updating the reference image data SD 0 with the second image data PD 2.The determination section 72 determines the presence or absence of foreign matter 92 on the basis of the difference in the feature values of the inspection area CA 0 acquired by performing the image processing on the updated reference image data SD 0 and the inspection image data CD 0 (step S 18 illustrated in FIG. 4 ). The determination section 72 may determine the presence or absence of foreign matter 92, as in the case where the board processing is normally performed.Specifically, the determination section 72 determines that foreign matter 92 is present in the inspection area CA 0 when the difference between the feature values of the inspection area CA 0 obtained from two image data PD 0 (in this case, updated reference image data SD 0 and inspection image data CD 0) exceeds a predetermined threshold value. When the difference between the feature values is equal to or less than the predetermined threshold, the determination section 72 determines that no foreign matter 92 is present in the inspection area CA 0. As described above, the feature value is not limited. In the embodiment, the feature value is the luminance of each pixel of two image data PD 0 (updated reference image data SD 0 and inspection image data CD 0).FIG. 8 shows an example of the state of the board 90 after resuming the board processing. FIG. 8 schematically illustrates the state of the board 90 after resuming the board processing in the component assembler M 2 based on image data PD 0, the first exemplary embodiment serving as an example. Specifically, the acquisition section 71 acquires the second image data PD 2 by imaging the inspection area CA 0 at the time when the board machining is resumed in the component assembler M 2, and updates the reference image data SD 0 with the second image data PD 2.In FIG. 8, the connector 93 is shown in black for convenience of illustration, and schematically illustrates that the connector 93 has changed over time while board processing has been interrupted. Then, the board 90 is transported to the next component mounter M 3 located on the downstream side of the component mounter M 2, and in the component mounter M 3, the acquisition section 71 acquires the inspection image data CD 0. When the reference image data SD 0 is not updated based on the second image data PD 2, the determination section 72 determines the presence or absence of foreign matter 92 based on the difference of the feature values of the inspection area CA 0 acquired by performing the image processing of the reference image data SD 0 illustrated in FIG. 7 and the inspection image data CD 0 illustrated in FIG. 8.In this case, there is a large difference between the feature value (connector 93 is white) of the inspection area CA 0 acquired by performing image processing on the reference image data SD 0 illustrated in FIG. 7 and the feature value (connector 93 is black) of the inspection area CA 0 acquired by performing image processing on the inspection image data CD 0 illustrated in FIG. 8, and the difference between the feature values exceeds the predetermined threshold value. According to the determination section 72, it is erroneously determined that foreign matter 92 is present in the inspection area CA 0. When the reference image data SD 0 is updated by the second image data PD 2, the determination section 72 determines the presence or absence of foreign matter 92 on the basis of the difference of the feature values of the inspection area CA 0 obtained by performing the image processing of the reference image data SD 0 illustrated in FIG. 8 and inspection image data CD 0.In this case, the difference between the feature value (connector 93 is black) of the inspection area CA 0 acquired by performing the image processing on the reference image data SD 0 illustrated in FIG. 8 and the feature value (connector 93 is black) of the inspection area CA 0 acquired by performing the image processing on the inspection image data CD 0 illustrated in FIG. 8 is small, and the difference between the feature values is equal to or less than the predetermined threshold value. Accordingly, the determination section 72 determines that no foreign matter 92 is present in the inspection area CA 0. That is, erroneous determination of foreign matters 92 due to the temporal change of the connection member 93 is suppressed. FIG. 8 shows a state of the board 90 after resuming the board processing, and the image data PD 0 of the component assembler M 1 on the upstream side of the component assembler M 2 is indicated by a space mark.When the determination section 72 determines that foreign matters 92 are present in the inspection area CA 0, the guidance section 74 gives the worker an instruction to the presence of foreign matters 92 (Yes in step S 19 and step S 20 illustrated in FIG. 4 ). The guide portion 74 can give the worker an instruction for the presence of foreign matter 92 in the same manner as in the case of the instruction for the presence of foreign matter 92 immediately after the board processing is interrupted. Then, the control by the foreign matter detection device 70 is temporarily ended.In the case of No in steps S 11 and S 19 illustrated in FIG. 4, control by the foreign matter detection device 70 is temporarily ended. In the case of No in step S 14, the control by the foreign matter detection device 70 proceeds to the control illustrated in step S 16. In the case of No in step S 16, the control by the foreign matter detection device 70 returns to the control illustrated in step S 16 and waits until the board processing is resumed.Moreover, the matters described in the present description may be combined, omitted, and selected as appropriate. For example, although the first embodiment is described in the present specification as an example, the facts described in the present specification can be applied to the second or third embodiment. The facts described in the present description can also be applied to a combination of the second and third embodiments. In the third embodiment, an imaging device capable of acquiring first image data PD 1 and second image data PD 2 is provided between adjacent component mounters WM 3 because the board 90 is transported between adjacent component mounters WM 3 in the embodiment. Moreover, in the first embodiment, the second embodiment, and the third embodiment, it is possible to adopt an embodiment in which the time required from acquisition of the reference image data SD 0 by the acquisition section 71 to acquisition of the inspection image data CD 0 is shorter than the above-described allowable time T 0 when the board processing is normally performed without interruption.2. Method for Detecting Foreign BodiesThe above-described foreign matter detection device 70 can be similarly applied to a method for foreign matter detection. The method for detecting foreign bodies comprises in particular a detection step and a determination step. The detection step corresponds to the control performed by the detection section 71. The determination step corresponds to the control performed by the determination section 72. The method for foreign body detection may comprise an estimation step. The estimation step corresponds to the control by the estimation section 73. The guiding step corresponds to the control performed by the guiding portion 74.3. Example of Effects of EmbodimentWith the foreign matter detection device 70, it is possible to acquire first image data PD 1 that is image data PD 0 at the time when the board processing is interrupted. The above description of the foreign matter detection device 70 can be similarly applied to the method for foreign matter detection.List of reference characters70: Foreign matter detection device, 71: detection section, 72: determination section, 73: estimation section, 74: guidance section, 90: board, 91: component, 92: foreign matter, 93: connection member, CA 0: inspection area, PD 0: image data, SD 0: reference image data, CD 0: inspection image data, PD 1: first image data, PD 2: second image data, Q 0: stop time, T 0: allowable time, WM 0: board processing machine, WM 3: component assembler.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 2007-335524 A

[0004]

Claims

A foreign matter detection device comprising: a detection section configured to image at least a part of an inspection area of a board according to progress of predetermined board processing by a board processing machine configured to perform the board processing on the board, and acquire a plurality of image data obtained by imaging the same inspection area; A determination section configured to determine the presence or absence of a foreign matter adhering to the inspection region based on a difference in feature values of the inspection region acquired by performing image processing of reference image data that is a part of a plurality of pieces of image data and inspection image data that is image data of an inspection target acquired after the reference image data, wherein the acquisition section acquires first image data that is image data at a time when board processing is interrupted by imaging the inspection region in a case where board processing is interrupted during a period from acquisition of the reference image data to acquisition of the inspection image data.The foreign matter detection device according to claim 1, wherein the determination section determines the presence or absence of the foreign matter on the basis of a difference in the feature values of the inspection area acquired by performing image processing on the reference image data and the first image data.The foreign matter detection device according to claim 2, further comprising: an estimation section configured to estimate a stop time from the time when the board machining is stopped to the time when the board machining is resumed, wherein the determination section determines the presence or absence of the foreign matter when the stop time is estimated to be longer than an allowable time in which a connector that is applied to the inspection area and connects the board and a component is not erroneously determined as the foreign matter even if the feature value of the inspection area is changed due to a temporal change of the connector.The foreign matter detection device according to claim 2, further comprising: an estimation section configured to estimate a stop time from the time when the board machining is interrupted to the time when the board machining is resumed, wherein the determination section determines the presence or absence of the foreign matter when the stop time is estimated to be longer than an allowable time in which a connector that is applied to the inspection area and connects the board and a component is not erroneously determined as a foreign matter even if the feature value of the inspection area is changed due to a temporal change of the connector after the stop time is estimated to be within the allowable time.The foreign matter detection device according to any one of claims 1 to 4, further comprising: a guide portion configured to guide the presence of the foreign matter to a worker when the determination portion determines that the foreign matter is present in the inspection area.The foreign matter detection device according to claim 1, wherein the acquisition section acquires, upon resumption of the board processing, second image data that is image data at a time when the board processing is resumed by imaging the inspection area, and updates the reference image data based on the second image data.The foreign matter detection device according to claim 6, wherein the acquisition section updates the reference image data based on the second image data in a case where a stop time from the time when the board processing is interrupted to the time when the board processing is resumed is longer than an allowable time in which a connector applied to the inspection area and connecting the board and a component is not erroneously determined as a foreign matter even if the feature value of the inspection area is changed due to a temporal change of the connector.The foreign matter detection device according to claim 6 or 7, wherein the determination section determines the presence or absence of the foreign matter based on a difference in the feature values of the inspection area acquired by performing image processing on the updated reference image data and the inspection image data.The foreign matter detection device according to claim 1, wherein the determination section determines that the foreign matter is present in the inspection area when a difference in the feature values of the inspection area acquired from two pieces of image data exceeds a predetermined threshold value, and determines that the foreign matter is not present in the inspection area when the difference in the feature values is equal to or less than the predetermined threshold value.The foreign matter detection device according to claim 9, wherein the feature value is luminance for each pixel of two image data.The foreign matter detection device according to claim 1, wherein the board is transported to a plurality of component mounters that are board processing machines in order, and a plurality of components are mounted on the board, the acquisition section acquires the reference image data in a component mounter on the most upstream side among the plurality of component holders, and acquires the inspection image data in a component mounter that mounts the component in the inspection area, and the determination section determines the presence or absence of foreign matter that adheres in the inspection area while the board is transported across the plurality of component mounters.The foreign matter detection device according to claim 1, wherein the board is transported to a plurality of component mounters that are board processing machines in order, and a plurality of components are mounted on the board, the acquisition section acquires the reference image data and the inspection image data in each of the plurality of component mounters, and the determination section determines the presence or absence of the foreign matter located in the inspection area in each of the component mounters.The foreign matter detection device according to claim 1, wherein the board is transported to a plurality of component mounters that are board processing machines in order, and a plurality of components are mounted on the board, the acquisition section acquires the reference image data in one component mounter among the plurality of component mounters and acquires the inspection image data in a next component mounter on a downstream side of the component mounter, and the determination section acquires the presence or absence of foreign matter that adheres in the inspection area when the board is transported between adjacent component mounters.A foreign matter detection method comprising: a detection step of imaging at least a part of an inspection area of a board according to progress of predetermined board processing by a board processing machine configured to perform the board processing on the board and acquire a plurality of pieces of image data obtained by imaging the same inspection area; A determination step of determining the presence or absence of a foreign matter adhering to the inspection region based on a difference in feature values of the inspection region obtained by performing image processing on reference image data that is a part of image data among the plurality of parts of image data and inspection image data that is image data of an inspection target acquired after the reference image data, wherein in the acquisition step, first image data that is image data at a time when board processing is interrupted by imaging the inspection region is acquired in a case where board processing is interrupted during a period from acquisition of the reference image data to acquisition of the inspection image data.

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