Printed circuit board inspection device and printed circuit board inspection method

Abstract

A printed circuit board inspection device or the like is provided that enables the specification of an adhesive-covered area with higher accuracy. The printed circuit board inspection device or the like captures an image of at least one area where adhesive is applied to a printed circuit board. The printed circuit board inspection device or the like specifies a central region of the adhesive in the captured image and also specifies a foot region of the adhesive surrounding the central region in the captured image using a specification procedure that differs from the specification procedure used to specify the central region.The printed circuit board inspection device or similar then specifies an entire area Ajs of the adhesive based on the specified midsection area and the specified foot section area. This configuration specifies the midsection and foot section areas, which each have different optical properties, separately by applying different specification procedures. This allows both the midsection and foot section areas to be specified with high accuracy, so that the area covered by the adhesive (the entire area Ajs) can be specified with greater accuracy. This improves the accuracy in assessing good / poor adhesive quality.

Description

Technical area

[0001] The present disclosure relates to a circuit board inspection apparatus configured to perform an inspection of a circuit board, such as a printed circuit board, and a circuit board inspection method. background

[0002] When mounting an electronic component on a printed circuit board, a general procedure involves first printing solder paste onto an electrode pattern placed on the printed circuit board. Then, the procedure utilizes the viscosity of the solder paste to temporarily attach an electronic component to the printed circuit board printed with the solder paste. Additionally, an adhesive (such as a thermosetting adhesive) may be applied to the printed circuit board to prevent the electronic component from falling off when the printed circuit board with the electronic component mounted on it passes through a specific reflow oven. After mounting the electronic component, the printed circuit board is inserted into the reflow oven and subjected to a predetermined reflow process to perform soldering.

[0003] Inspection of the adhesive application state may be performed in a step prior to the reflow process. For example, a known inspection procedure for the adhesive application state specifies (extracts) an area occupied by the adhesive (actual adhesive area) from image data obtained by imaging the printed circuit board, and then performs inspection based on a positional relationship between the specified actual adhesive area and the solder paste, or the like (as described in Patent Document 1, for example). Luminance data is an example of such image data.

[0004] One technique using color images is a known procedure for specifying (extracting) the area occupied by the adhesive (as described in Patent Document 2, for example). In this technique, a color image signal is compared with a predetermined color distribution of the adhesive, and a portion of the color image containing the colors of the color distribution is specified as the area occupied by the adhesive. BibliographyPatent literature Patent document 1: JP 6 262 378 B Patent Document 2: JP H06-347 419 A Brief descriptionTechnical problem

[0005] The adhesive is generally translucent. However, if the adhesive application thickness is sufficiently large over the entire area, the area occupied by the adhesive can be precisely specified by color, as described in Patent Document 2.

[0006] However, the actual application thickness of the adhesive is not constant or uniform across the entire area, but is relatively thin in an outer edge side section (foot section). Such a section with a relatively thin application thickness may be influenced by a part underneath the adhesive, resulting in a different color than a section with a sufficiently thick application thickness. Therefore, a procedure that simply exploits the color will likely only specify the area with a sufficiently thick application thickness, not the actual area occupied by the adhesive. Therefore, there is a possibility that the area occupied by the adhesive may not be accurately specified.

[0007] In view of the above circumstances, it is an object of the present disclosure to provide a printed circuit board inspection apparatus or the like which makes it possible to specify an area occupied by an adhesive with higher accuracy. Solution to the task

[0008] Below, each of the various aspects appropriately provided to solve the above problem is described. Also described, as applicable, are functions and beneficial effects characteristic of each of the aspects.

[0009] Aspect 1. A printed circuit board inspection apparatus is provided that is configured to perform an inspection of an adhesive applied to the printed circuit board. The printed circuit board inspection apparatus includes an imaging unit configured to capture an image of at least one region in the printed circuit board where the adhesive is applied; a center portion specifying unit configured to specify a center portion region of the adhesive in a captured image obtained by the imaging unit; a foot portion specifying unit configured to specify a foot portion region of the adhesive around the center portion region in the captured image through a specification procedure different from a specification procedure of the center portion region by the center portion specifying unit;an entirety specifying unit configured to specify an entire area of ​​the adhesive based on the middle portion area specified by the middle portion specifying unit and the foot portion area specified by the foot portion specifying unit; and a determining unit configured to perform a good / poor quality judgment on the adhesive based on the overall area specified by the entirety specifying unit.

[0010] In the configuration of aspect 1 above, the center portion specifying unit specifies the center portion area of ​​the adhesive in the captured image. On the other hand, the foot portion specifying unit specifies the foot portion area (a region on an outer edge side) of the adhesive, which is generally thinner than the thickness of the center portion area, through a specification procedure different from the specification procedure for the center portion area. Finally, the entirety specifying unit specifies the entire area of ​​the adhesive based on the center portion area and the foot portion area, which are respectively specified.As described above, the configuration of aspect 1 above uses different specification procedures to separately specify the center portion region and the base portion region, each having different optical properties, thereby making it possible to specify both the center portion region and the base portion region with high accuracy. This allows an area occupied by the adhesive to be specified with higher accuracy. This results in improving the accuracy of judgment of good / poor quality with respect to the adhesive (e.g., judgment of good / poor quality with respect to an application area of ​​the adhesive and judgment of good / poor quality with respect to a relative positional relationship of the adhesive to the solder, or the like).

[0011] Aspect 2. In the printed circuit board inspection apparatus according to aspect 1 above, the adhesive may have a red color; and the center portion specifying unit may be configured to extract a red color region from a color tone image based on the captured image or extract a region with a luminance higher than a predetermined luminance reference value from a red luminance image based on the captured image, in a process of specifying the center portion region.

[0012] The red adhesive is widely used. The configuration of the above aspect 2 makes it possible to specify the center section area of ​​such a red adhesive more accurately and easily.

[0013] Aspect 3. In the printed circuit board inspection apparatus according to aspect 1 above or aspect 2 above, the printed circuit board may have a green resist area; the adhesive may have a red color and may be applied to the resist area; and the root portion specifying unit may be configured to extract an area with a saturation lower than a predetermined saturation reference value from a saturation image based on the captured image, in a process of specifying the root portion area.

[0014] In the circuit board with the red adhesive applied to the green resist area, a portion with a relatively thin adhesive application thickness is influenced by the green resist area, thereby exhibiting relatively low saturation. Utilizing this feature, the configuration of the above aspect 3 extracts the low saturation area from the saturation image based on the captured image in the process of specifying the root portion area. This configuration makes it possible to specify the root portion area of ​​the adhesive more accurately and easily.

[0015] Aspect 4. In the printed circuit board inspection apparatus according to any one of the above aspects 1 to 3, at least one of the center portion specifying unit, the foot portion specifying unit, and the entirety specifying unit may be configured to perform a process of excluding a region related to a screen printing provided on the printed circuit board from a corresponding finally specified region.

[0016] The “corresponding finally specified area” means the center section area in the center section specifying unit, the foot section area in the foot section specifying unit, and the entire area in the entirety specifying unit.

[0017] The configuration of aspect 4 above more reliably prevents an area related to a screen print (a printed portion printed on the circuit board and displaying information including letters, characters, symbols, marks, and the like) from being mistakenly specified as the area related to the adhesive (the center portion area, the foot portion area, or the entire area). This configuration makes it possible to specify the area related to the adhesive with higher accuracy.

[0018] Aspect 5. A printed circuit board inspection method for performing an inspection of an adhesive applied to a printed circuit board is provided. The printed circuit board inspection method includes an imaging process for capturing an image of at least one region in the printed circuit board where the adhesive is applied; a center portion specifying process for specifying a center portion region of the adhesive in a captured image obtained by the imaging process; a foot portion specifying process for specifying a foot portion region of the adhesive around the center portion region in the captured image by a specifying procedure different from a specifying procedure of the center portion region by the center portion specifying process;an entirety specifying process for specifying an entire area of ​​the adhesive based on the middle section area specified by the middle section specifying process and the foot section area specified by the foot section specifying process; and a determination process for performing a good / poor quality judgment on the adhesive using the entire area specified by the entirety specifying process.

[0019] The configuration of the above aspect 5 has functions and advantageous effects similar to those of the above-described aspect 1. The technical features related to each of the above aspects 2 to 4 can be applied to the configuration of the above aspect 5. Short description of the drawings Fig. 1 is a partially enlarged schematic plan view showing the schematic configuration of a printed circuit board; Fig. Fig. 2 is a partially enlarged schematic sectional view showing the printed circuit board; Fig. 3 is a block diagram showing the configuration of a printed circuit board manufacturing line; Fig. 4 is a schematic configuration diagram schematically illustrating a printed circuit board inspection apparatus; Fig. 5 is a block diagram illustrating the functional configuration of the printed circuit board inspection apparatus; Fig. 6 is a block diagram illustrating the functional configuration of an adhesive inspection unit; Fig. Figure 7 shows a figure simply representing a color wheel in an HSV color space; Fig. 8 is a flowchart illustrating a mid-section specifying process; Fig. Fig. 9 is a diagram showing an example of a tone image; Fig. 10 is a diagram showing an example of a center portion extraction image; Fig. 11 is a flowchart illustrating a foot section specifying process; Fig. 12 is a diagram showing an example of a saturation image; Fig. 13 is a diagram showing an example of a reverse saturation image; Fig. 14 is a diagram illustrating an example of a binarized inverse saturation image; Fig. 15 is a diagram illustrating an example of a binarized inverse brightness image; Fig. 16 is a diagram showing an example of a foot portion extraction image; Fig. 17 is a diagram showing an example of an adhesive extraction image; Fig. 18 is a schematic plan view illustrating an inspection of only one adhesive; Fig. 19 is a schematic plan view illustrating an inspection of a positional relationship between solder and an adhesive; Fig. 20 is a schematic plan view illustrating an inspection of a positional relationship between an adhesive portion and a planned location area of ​​an electrode portion; Fig. 21 is a flowchart illustrating the center section specifying process according to another embodiment; Fig. Fig. 22 is a diagram illustrating an example of a red luminance image; Fig. 23 is a figure showing an example of a binarized red luminance image; Fig. 24 is a figure showing an example of a binarized saturation image; Fig. 25 is a diagram illustrating an example of the center portion extraction image according to another embodiment; Fig. 26 is a diagram illustrating an example of an adhesive and screen printing extraction image; Fig. 27 is a flowchart illustrating a screen printing area exclusion process according to another embodiment; Fig. Fig. 28 is a diagram showing an example of a brightness image; Fig. 29 is a figure showing an example of a binarized brightness image; Fig. 30 is a diagram showing an example of a screen printing image; Fig. 31 is a diagram illustrating an example of a reverse screen printing image; and Fig. 32 is a diagram illustrating an example of an adhesive portion extraction image according to another embodiment. Description of embodiments

[0020] An embodiment will be described below with reference to the drawings. First, the configuration of a printed circuit board as a circuit board will be described.

[0021] As in the Fig. 1 and Fig. As shown in Figure 2, a printed circuit board 1 (hereinafter referred to simply as "printed circuit board 1") is configured by forming pads 3 made of copper foil, a predetermined electrode pattern (not shown), and the like on a flat, plate-like base substrate 2 composed of, for example, a glass epoxy resin. Solder paste 4 obtained by kneading solder particles with flux (hereinafter referred to simply as "solder 4") is printed on the pads 3.

[0022] Electronic components 5, such as chips, are mounted on the solder 4. More specifically, each electronic component 5 has a plurality of electrode portions 5a configured by electrodes, leads, and the like. Each of the electrode portions 5a is connected to a predetermined portion of the solder 4.

[0023] According to the embodiment, the electronic component 5, which is fixed by the solder 4, is additionally bonded with an adhesive (in Fig. 1 as an area filled with oblique lines) to reinforce the fixation. The adhesive 6 is an insulating adhesive with thermosetting property. The adhesive 6 is a red-colored, translucent liquid that is viscous at least in the state before curing. In the plan view of the circuit board 1, the adhesive 6 is configured to have a center portion 6a and a foot portion 6b around the center portion 6a. In the state before mounting the electronic component 5, the deposition thickness in the center portion 6a is generally relatively large, while the deposition thickness in the foot portion 6b located on an outer peripheral side of the adhesive 6 is relatively small.

[0024] A green resist area 7 (in Fig. 1 as an area filled with a dotted pattern) is provided at a location different from the terminal pads 3 on the surface of the base substrate 2. The resist region 7 is made of an insulating resist and serves to coat the base substrate 2 and the electrode pattern described above. According to the embodiment, the adhesive 6 is applied to the resist region 7.

[0025] Furthermore, a screen print 8 is provided in the resist area 7. This is a printed portion in which information such as letters, characters, symbols, and the like is printed. The color of the screen print 8 is generally white or yellow, and according to the embodiment, it is white.

[0026] The following describes a production line (a production process) for manufacturing the printed circuit board 1. As shown in Fig. 3, a production line 10 comprises a solder printing machine 11, an adhesive application device 12, a printed circuit board inspection device 13, a component placement machine 14, a reflow device 15 and a post-reflow inspection device 16, which are arranged sequentially from an upstream side (in Fig. 3 from the top). The circuit board 1 is to pass through these devices and machines in this order.

[0027] The solder printing machine 11 is configured to print predetermined amounts of the solder 4 at predetermined positions (e.g., on the terminal pads 3) of the printed circuit board 1. More specifically, the solder printing machine 11 is equipped with a metal screen (not shown) having a plurality of holes formed at positions corresponding to the terminal pads 3 and the like on the printed circuit board 1, and which serves to screen-print the solder 4 onto the printed circuit board 1 using the metal screen.

[0028] The adhesive application device 12 is configured to apply predetermined amounts of the adhesive 6 to predetermined positions (e.g., positions where the electronic components 5 are to be placed) on the circuit board 1. The adhesive application device 12 is equipped, for example, with a nozzle head (not shown) that is movable in the XY direction and serves to eject the adhesive 6 from the nozzle head, thereby applying the adhesive 6 in the resist area 7.

[0029] The printed circuit board inspection device 13 is configured to perform an inspection of the applied adhesive 6. The printed circuit board inspection device 13 also has an inspection function for performing an inspection of the condition of the printed solder 4 and the presence or absence of foreign matter on the printed circuit board 1. The printed circuit board inspection device 13 will be described in more detail below.

[0030] The component mounting machine 14 is configured to perform a component mounting process (mounting process) in which the electronic components 5 are mounted on the pads and the like on which the solder 4 is printed. This temporarily attaches the respective electrode portions 5a of the electronic components 5 to predetermined portions of the solder 4.

[0031] The reflow device 15 is configured to heat and melt the solder 4 and to heat and cure the adhesive 6. In the circuit board 1 subjected to a reflow process by the reflow device 15, the terminal pad 3 is connected to the electrode portion 5a of the electronic component 5 using the solder 4, and the electronic component 5 is firmly fixed using the adhesive 6.

[0032] The post-reflow inspection device 16 is configured to perform a post-reflow inspection process, which, for example, determines whether a solder joint was properly formed during the reflow process. The post-reflow inspection process uses, for example, image data of the circuit board 1 after the reflow process to determine whether a positioning error of the electronic component 5 exists.

[0033] The production line 10 additionally includes conveyors or the like provided between the respective devices described above, for example, between the solder printing machine 11 and the adhesive application device 12, and configured to transport the printed circuit board 1, although they are not specifically shown. The production line 10 also includes branching units between the printed circuit board inspection device 13 and the component placement machine 14, and on a downstream side of the post-reflow inspection device 16. The printed circuit board 1 determined to be defect-free by the printed circuit board inspection device 13 and the post-reflow inspection device 16 is directly transferred to a downstream side, while the printed circuit board 1 determined to be defective by either of the inspection devices 13 and 16 is transferred from the branching unit to a defect storage unit (not shown).

[0034] The configuration of the printed circuit board inspection device 13 is described below. As shown in the Fig. 4 and Fig. 5, the printed circuit board inspection apparatus 13 includes a transfer mechanism 31 configured to perform transfer, positioning, and the like of the printed circuit board 1; an inspection unit 32 configured to perform inspection of the printed circuit board 1; and a control device 33 configured to drive and control the transfer mechanism 31 and the inspection unit 32 and to perform various controls, image processing, and arithmetic processing in the printed circuit board inspection apparatus 13.

[0035] The transfer mechanism 31 includes a pair of transfer rails 31a arranged along a transport direction of the printed circuit board 1, and an endless conveyor belt 31b arranged to be rotatable relative to the respective transfer rails 31a. The transfer mechanism 31 is also equipped with a drive unit, such as a motor, that drives the conveyor belt 31b, and a clamping mechanism that positions the printed circuit board 1 at a predetermined position, although these components are not specifically shown. The transfer mechanism 31 is driven and controlled by the control device 33 (more specifically, by a transfer mechanism controller 339 described later).

[0036] Under the configuration described above, when the printed circuit board 1 is transported into the printed circuit board inspection device 13, the respective side edge portions of the printed circuit board 1 are inserted into the respective transfer rails 31a in a width direction perpendicular to the transport direction, and the printed circuit board 1 is placed on the transport belt 31b. Subsequently, the conveyor belt 31b is operated to transport the printed circuit board 1 to a predetermined inspection position. When the printed circuit board 1 reaches the inspection position, the conveyor belt 31b stops and the clamping mechanism is actuated. By this actuation of the clamping mechanism, the conveyor belt 31b is pushed up, and the respective side edge portions of the printed circuit board 1 are placed between the conveyor belt 31b and the respective upper surfaces of the transfer rails 31a. Thus, the printed circuit board 1 is positioned and fixed at the inspection position.After the inspection is completed, the clamping mechanism is released, and the conveyor belt 31b begins operation. The printed circuit board 1 is accordingly conveyed out of the printed circuit board inspection device 13. The configuration of the transfer mechanism 31 is, of course, not limited to the configuration of this embodiment described above; other configurations may also be used.

[0037] The inspection unit 32 is located above the transfer rails 31a (above the transfer path of the printed circuit board 1). The inspection unit 32 includes an illumination device 321 and a camera 322. According to the embodiment, the camera 322 constitutes the "imaging unit."

[0038] The inspection unit 32 also includes an X-axis movement mechanism 323 which performs movements in an X-axis direction (left-right direction in Fig. 4) and a Y-axis movement mechanism 324 that enables movements in a Y-axis direction (front-back direction in Fig. 4). The two movement mechanisms 323 and 324 are driven and controlled by the control device 33 (more precisely, by a movement mechanism controller 338 described below).

[0039] The illumination device 321 is configured to irradiate the printed circuit board 1, which is an inspection object of the printed circuit board inspection device 13, with a predetermined light. Specifically, the illumination device 321 includes a first ring light 321a, a second ring light 321b, and a third ring light 321c (as shown in Fig. 4).

[0040] The first ring light 321a is configured to illuminate the circuit board 1 with light emitted from an approximately horizontal direction. The second ring light 321b is located above the first ring light 321a and is configured to illuminate the circuit board 1 with light emitted obliquely downward. The third ring light 321c is located on an inner side of the second ring light 321b and is configured to illuminate the circuit board 1 with light emitted downward from an approximately vertical direction.

[0041] Each of the ring lights 321a, 321b, and 321c illuminates the circuit board 1 with white light. Specifically, each of the ring lights 321a, 321b, and 321c simultaneously illuminates the circuit board 1 with multiple colored lights, i.e., red, blue, and green light.

[0042] The camera 322 is arranged with its optical axis extending in the vertical direction (Z-axis direction) and configured to capture an image of a predetermined inspection target area from directly above the printed circuit board 1, which is the inspection object. The "inspection target area" of the printed circuit board 1 refers to one of a plurality of areas defined in advance in the printed circuit board 1, with the size of an imaging field (imaging area) of the camera 322 as a unit.

[0043] The camera 322 is configured as a color camera and is operated and controlled by the control device 33 (more specifically, by a camera controller 333 described later). The operation control of the control device 33 causes the camera 322 to capture an image of an inspection target area, including at least an area where the adhesive 6 is applied, in the printed circuit board 1 when the printed circuit board 1 is simultaneously irradiated with the lights of the respective ring lights 321a, 321b, and 321c. In this way, an RGB luminance image is obtained with respect to the inspection target area. This RGB luminance image has a large number of pixels, and for each of these pixels, three different parameter values ​​for R (red), G (green), and B (blue) are determined. According to the embodiment, these parameter values ​​are specified in a range from 0 to 1.The process of capturing an image of at least the area where the adhesive 6 is applied to the circuit board 1 by the camera 322 corresponds to the "imaging process." The RGB luminance image corresponds to the "captured image."

[0044] The RGB luminance image obtained by the camera 322 is transmitted to the control device 33 (more specifically, to a color image acquisition unit 334 described below). The control device 33 performs an inspection process with respect to the adhesive 6 based on this RGB luminance image.

[0045] The control device 33 is configured by a computer including, for example, a CPU (Central Processing Unit) that performs predetermined arithmetic operations; a ROM (Read Only Memory) that stores a variety of programs, read-only data, and the like; a RAM (Random Access Memory) that temporarily stores various data in the course of executing various arithmetic operations; and peripheral circuits of the foregoing.

[0046] The CPU operates according to the plurality of programs, so that the control device 33 serves as a plurality of functional parts, such as a main controller 331, an illumination controller 332, a camera controller 333, a color image sensing unit 334, an electrode portion area generator 335, a solder specifying unit 336, an adhesive inspection unit 337, a moving mechanism controller 338, and a transfer mechanism controller 339.

[0047] However, the respective functional parts described above are realized through the cooperation of various hardware components, such as the CPU, ROM, and RAM. There is no need to clearly distinguish the functions realized by the hardware configuration and those realized by the software configuration. Part or all of these functions can be realized by a hardware circuit such as an IC. The control device 33 also includes a functional part configured to perform an inspection regarding the condition of the solder 4 and the presence or absence of foreign matter on the circuit board 1. However, the explanation of this functional part is omitted from the description of the embodiment.

[0048] The control device 33 is further provided with an input unit 340 configured by a keyboard and mouse, a touch panel, or the like; a display unit 341 configured by a liquid crystal display or the like and provided with a display screen; a storage unit 342 configured to store a variety of data and programs, the results of arithmetic operations, the results of inspection, and the like; and a communication unit 343 configured to receive and transmit a variety of data from the outside. First, the storage unit 342 and the communication unit 343 will be described.

[0049] The storage unit 342 is implemented, for example, as an HDD (hard disk drive) or SSD (solid state drive) to store various pieces of information. The storage unit 342 includes an image storage section 342a, an inspection information storage section 342b, and an inspection result storage section 342c.

[0050] The image storage section 342a is configured to store the RGB luminance image captured and obtained by the camera 322. The image storage section 342 also stores a variety of images, including hue images and saturation images, each of which will be described below. Each of the images stored in the image storage section 342a can be displayed on the display unit 341 as needed.

[0051] The inspection information storage section 342b is configured to store various pieces of information used for inspecting the printed circuit board 1. The inspection information storage section 342b stores, for example, a series of reference and threshold values ​​used when processing an image through a binarization process or when judging good / poor quality of an image, as well as design data and manufacturing data. The design data and manufacturing data include, for example, planned application positions of the adhesive 6, the dimensions of the adhesive 6 in the ideal application state (e.g., the area, contour length, and volume of the adhesive 6), and various pieces of information related to the electronic components 5, including the size and a planned location range of each of the electrode portions 5a.

[0052] The inspection result storage section 342c is configured to store inspection result data from the adhesive inspection unit 337. The inspection result storage section 342c also stores, for example, inspection result data on the condition of the solder 4 and the presence or absence of foreign matter on the printed circuit board 1, as well as statistical data obtained by stochastic and statistical processing of the various inspection result data. These inspection result data and these statistical data can each be displayed on the display unit 341.

[0053] The communication unit 343 is equipped, for example, with a communication interface conforming to a communication standard such as a wired LAN (Local Area Network) or a wireless LAN, and is configured to receive and transmit a variety of data from the outside. For example, the results of an inspection by the adhesive inspection unit 337 are output to the outside via the communication unit 343, and the results of an inspection by the post-reflow inspection device 16 are input via the communication unit 343.

[0054] The above-mentioned respective functional parts of the control device 33 are described in detail below. First, the movement mechanism controller 338 and the transfer mechanism controller 339 are described, followed by the main controller 331 and the like.

[0055] The movement mechanism controller 338 is a functional part that serves to drive and control the X-axis movement mechanism 323 and the Y-axis movement mechanism 324, and is configured to control the position of the inspection unit 32 in response to a command signal from the main controller 331. The movement mechanism controller 338 drives and controls the X-axis movement mechanism 323 and the Y-axis movement mechanism 324 to move the inspection unit 32 to a position above any inspection target area in the printed circuit board 1, which is positioned and fixed at an inspection position. As the inspection unit 32 is sequentially moved to each of a plurality of inspection target areas defined in the printed circuit board 1, an inspection is performed with respect to each of the inspection target areas. This performs an inspection of the entire area of ​​the printed circuit board 1.

[0056] The transfer mechanism controller 339 is a functional part for driving and controlling the transfer mechanism 31 and is configured to control the transfer position of the circuit board 1 in response to a command signal from the main controller 331.

[0057] The main controller 331 and the like are described below. The main controller 331 is a functional part for controlling the entire printed circuit board inspection device 13 and is configured to send and receive a variety of signals to and from the other functional parts, including the lighting controller 332 and the camera controller 333.

[0058] The lighting controller 332 is a functional part for driving and controlling the lighting device 321. The lighting controller 332 is configured to perform timing control regarding the emission of light from the lighting device 321 to the circuit board 1 and regarding termination of the emission in response to command signals from the main controller 331.

[0059] The camera controller 333 is a functional part for driving and controlling the camera 332. The camera controller 333 is configured to control, for example, the imaging timing of the circuit board 1 by the camera 332 in response to a command signal from the main controller 331.

[0060] The color image acquisition unit 334 is a functional part for acquiring the RGB luminance image captured and obtained by the camera 322. The RGB luminance image acquired by the color image acquisition unit 334 is stored in the image storage section 342a.

[0061] The electrode section area generator 335 is configured to generate an electrode section area Adh (in Fig. 20) indicating a planned location area of ​​the electrode portion 5a of the electronic component 5. According to the embodiment, the electrode portion area generator 335 essentially generates a planned location area of ​​the electrode portion 5a based on the design data or the manufacturing data as the electrode portion area Adh. In the event that an actual area occupied by the actual solder 4 (a solder area Ajh described below) deviates from an ideal area occupied by the ideal solder 4, the electrode portion area generator 335 adjusts the electrode portion area Adh according to this deviation.

[0062] The solder specifying unit 336 is configured to specify an area occupied by the solder 4 (hereinafter referred to as "solder area Ajh") on the printed circuit board 1 based on the RGB luminance image obtained from the camera 322. Specifically, the solder specifying unit 336 performs, for example, a binarization process in which a predetermined luminance value set in advance for the RGB luminance image is used as a reference value to specify the solder area Ajh, which indicates a flat area occupied by the solder 4.A modified configuration of the solder specifying unit 336 may set a search area corresponding to a planned deposition position of the solder 4, and may exclude a flat area of ​​the solder 4 having an extremely small area from the solder area Ajh based on a ratio of the area of ​​the solder 4 located in the search area to the total area of ​​the search area.

[0063] The adhesive inspection unit 337 is configured to perform an inspection of the adhesive 6 applied to the circuit board 1. As shown in Fig. As shown in Figure 6, the adhesive inspection unit 337 includes various functional modules, including a center portion specifying module 337a, a foot portion specifying module 337b, an entirety specifying module 337c, and a determination module 337d. According to the embodiment, the center portion specifying module 337a configures the "center portion specifying unit." Similarly, the foot portion specifying module 337b, the entirety specifying module 337c, and the determination module 337d configure the "foot portion specifying unit," the "entirety specifying unit," and the "determination unit."

[0064] The center section specifying module 337a is configured to perform a center section specifying process that specifies a center section area Ajsa (in Fig. 10), which is an area corresponding to the central portion 6a in the RGB luminance image described above.

[0065] As in Fig. 8, the center portion specifying process, in step S11, first obtains a hue image with respect to the inspection target area of ​​the printed circuit board 1 using the RGB luminance image obtained from the camera 322. More specifically, the center portion specifying process calculates a hue (hereinafter referred to as "hue H") of each pixel in a color circle of an HSV color space with 0 degrees (360 degrees) set as red, 60 degrees as yellow, 120 degrees as (strict) green, 180 degrees as cyan, 240 degrees as blue, and 300 degrees as magenta (as shown in Fig. 7), and obtains a hue image in which the hue H is correlated with each of the pixels. The hue image is stored in the image storage section 342a.

[0066] Hue H is calculated using mathematical expression 1, mathematical expression 2, or mathematical expression 3, shown below. Mathematical expression 1 is used when a parameter value of B is the maximum among the respective parameter values ​​with respect to R, G, and B. Mathematical expression 2 is used when a parameter value of R is the maximum among the respective parameter values ​​with respect to R, G, and B. Mathematical expression 3 is used when a parameter value of G is the maximum among the respective parameter values ​​with respect to R, G, and B. Hue H is not defined if a maximum value and a minimum value of the respective parameter values ​​with respect to R, G, and B are equal: <Mathematischer Ausdruck 1> H=60×(G−R) / (MAX−MIN)+60 <Mathematischer Ausdruck 2> H=60×(B−G) / (MAX−MIN)+180 <Mathematischer Ausdruck3> H=60×(R−B) / (MAX−MIN)+300

[0067] In mathematical expressions 1 to 3, R, G, and B respectively denote the parameter values ​​with respect to R, with respect to G, and with respect to B; MAX represents the maximum value among the respective parameter values; and MIN represents the minimum value among the respective parameter values.

[0068] The hue image refers to an image that specifies the hues of the respective pixels of the RGB luminance image in the color circle of the HSV color space. Fig. Figure 9 shows an example of the color tone image. The color image includes, for example, the adhesive 6 and the screen print 8.

[0069] In the RGB luminance image, while the central portion 6a with a relatively large deposition thickness has a red color, the base portion 6b with a relatively small deposition thickness is influenced by the green resist area 7 as a base and is approximately black. Accordingly, in the obtained color tone image, the central portion 6a is relatively dark, while the base portion 6b is relatively bright (as in Fig. 9). In the color image, screen print 8 is relatively light.

[0070] After the color tone image is obtained, the center portion specifying process in step S12 then processes the color tone image through a binarization process using a predetermined color tone reference value to extract a red color area (ie, an area including the center portion 6a) from the color tone image, thereby obtaining a center portion extraction image. Fig. Figure 10 shows an example of the center-portion extraction image. The hue reference value is set based on the hue of the center portion 6a in the hue image.

[0071] The center portion extraction image is a black and white image with 0 (bright part) and 1 (dark part) and is stored in the image storage section 342a. According to the embodiment, the bright part of the center portion extraction image, which corresponds to the red color area in the color tone image, is specified as the center portion area Ajsa (see Fig. 10). In the case of specifying the center section area Ajsa, a filling process or the like may be performed to eliminate isolated points. If another red color area other than the red color area of ​​the adhesive 6 exists in the RGB luminance image, an elimination process for eliminating this other red color area may be performed based on the design data or the manufacturing data to exclude this red color area from the center section area Ajsa.

[0072] The foot portion specifying module 337b is configured to perform a foot portion specifying process that specifies a foot portion area Ajsb located around the center portion area Ajsa and corresponding to the foot portion 6b of the adhesive 6 in the RGB luminance image. The foot portion specifying process specifies the foot portion area Ajsb through a specification procedure that is different from the specification procedure of the center portion area Ajsa by the center portion specifying module 337a.

[0073] As in Fig. As shown in Figure 11, the foot portion specifying process, in step S21, first obtains a saturation image related to the inspection target area of ​​the printed circuit board 1 using the RGB luminance image stored in the image storage section 342a. Specifically, the foot portion specifying process uses Mathematical Expression 4 below to calculate a saturation S (saturation in the HSV system) of each of the pixels in the RGB luminance image and obtains a saturation image in which the saturation S is correlated with each of the pixels. The saturation image is stored in the image storage section 342a: <Mathematischer Ausdruck 4> S=(1-3×MIN / (R+G+B))

[0074] As in mathematical expressions 1 to 3, in mathematical expression 4, R, G, and B respectively denote the parameter values ​​related to R, G, and B; and MIN represents the minimum value among the respective parameter values. The saturation S of each pixel in the saturation image is expressed in a range from 0 to 1. The saturation S of the pixel closer to 1 means that the color of the pixel is closer to the primary color. The saturation S can be calculated using mathematical expression 4a below, which replaces mathematical expression 4. <Mathematischer Ausdruck 4a> S=(MAX−MIN) / MAX

[0075] The saturation map is an image that indicates the saturations of the respective pixels in the RGB luminance image. Fig. Figure 12 shows an example of the saturation image. The saturation image includes, for example, the adhesive 6 and the screen print 8.

[0076] In the RGB luminance image, the foot portion 6b, which has a relatively thin deposition thickness, is influenced by the green resist area 7 as the base and has low saturations. Accordingly, in the obtained saturation image, the foot portion 6b is relatively dark (as in Fig. 12). In the saturation image, the screen print 8 is also relatively dark. In contrast, the central section 6a and the resist area 7 are relatively bright in the saturation image.

[0077] In step S22, the foot portion specifying process obtains an inverse saturation image by inverting the saturation image to extract a region with relatively low saturations (ie, a region including the foot portion 5b) from the saturation image. Fig. Figure 13 shows an example of the reverse saturation image. In the reverse saturation image, the foot section 6b and the screen print 8 are relatively bright.

[0078] After step S22, the foot portion specifying process then processes the inverse saturation image through a binarization process using a predetermined saturation reference value, and thereby obtains a binarized inverse saturation image in step S23. Fig. 14 shows an example of the binarized inverse saturation image. The binarized inverse saturation image is a black and white image with 0 (bright part) and 1 (dark part) and is stored in the image storage section 342a. In the binarized inverse saturation image, not only the foot portion 6b but also the screen print 8 is a bright part. The saturation reference value is set based on the respective saturations of the foot portion 6b and the resist area 7 in the binarized inverse saturation image.

[0079] In step S24, the foot portion specifying process then performs a screen printing area exclusion process to exclude an area related to the screen printing 8 from the binarized inverse saturation image. The screen printing area exclusion process first obtains a binarized inverse luminance image based on the RGB luminance image to extract a particularly low luminance area (value) from the RGB luminance image in step S241. A procedure for obtaining the binarized inverse luminance image first uses Mathematical Expression 5 below to calculate a value V (brightness in the HSV system) of each pixel in the RGB luminance image, thereby obtaining a luminance image in which the value V is correlated with each of the pixels. The luminance image refers to an image indicating the luminance of each pixel in the RGB luminance image; <Mathematischer Ausdruck 4> V=MAX

[0080] As in mathematical expressions 1 to 3, MAX in mathematical expression 5 represents the maximum value among the respective parameter values ​​with respect to R, G, and B.

[0081] The procedure then processes the brightness image through an inversion process and a binarization process, thereby obtaining a binarized inversion brightness image. Fig. Figure 15 shows an example of the binarized reverse brightness image. During this binarization process, a brightness reference value is used to exclude (not extract) an area related to the screen print 8, but to extract an area related to the foot portion 6b. To more reliably exclude the area related to the screen print 8, an additional process can be performed separately to obtain a screen print image described later (in Fig. 30) and to exclude the area related to the screen print 8 from the binarized reverse brightness image by using the screen print image.

[0082] In step S242, the screen print area exclusion process calculates a logical AND operation of the obtained binarized reverse saturation image and the obtained binarized reverse brightness image to exclude the area related to the screen print 8 from the binarized reverse saturation image. The foot portion specification process accordingly obtains a foot portion extraction image. Fig. 16 shows an example of the foot portion extraction image. The foot portion extraction image is a black and white image with 0 (bright part) and 1 (dark part) and is stored in the image storage section 342a. According to the embodiment, the bright part in the foot portion extraction area is specified as the foot portion area Ajsb.

[0083] When specifying the root portion area Ajsb, a modified configuration may separately perform a process to exclude areas related to the pads 3 and the electrode pattern that are expected to have relatively low saturations. For example, this process may refer to the positions of the pads 3 and the like in the design data or the manufacturing data and exclude low-saturation areas located at these positions from the binarized reverse saturation image.

[0084] The entirety specification module 337c is configured to perform an entirety specification process that specifies an entire area Ajs of the adhesive 6 (in Fig. 17) based on the center portion area Ajsa specified by the center portion specifying module 337a and the foot portion area Ajsb specified by the foot portion specifying module 337b. The entirety specifying process calculates a logical AND operation of the center portion extraction image and the foot portion extraction image to obtain an adhesive extraction image. Fig. Figure 17 shows an example of the adhesive extraction image. The adhesive extraction image is a black and white image with 0 (bright part) and 1 (dark part) and is stored in the image storage section 342a. According to the embodiment, the bright part in the adhesive extraction image is specified as the entire area Ajs.

[0085] When obtaining the adhesive extraction image, if there is an isolated point (dark part) between the middle section area Ajsa and the foot section area Ajsb, a filling process (a process that treats the isolated point as a bright part) can be performed to fill the isolated point.

[0086] As described above, the configuration of the embodiment performs the process of capturing an image of the printed circuit board 1 using the camera 322 (the imaging process), the center portion specifying process, the foot portion specifying process, and the entirety specifying process to finally specify the entire area Ajs. Performing the respective processes described above with respect to all inspection target areas on the printed circuit board 1 as the object specifies the entire areas Ajs with respect to all portions of the adhesive 6 provided on the printed circuit board 1.

[0087] The determination module 337d performs a determination process that performs a good / poor quality assessment of the adhesive 6 based on the entire area Ajs specified by the entirety specification module 337c. The determination process generates an adhesive inspection window Krs (in Fig. 18) showing a reference inspection area of ​​the adhesive 6 based on the design data or the manufacturing data stored in the inspection information storage section 342b. The adhesive inspection window Krs serves as a judgment criterion for good / poor quality based solely on the dimensions and position of the adhesive 6. The adhesive inspection window Krs has a shape similar to the shape of a flat area occupied by the adhesive 6 in the data and indicates an area where the center coordinates of the adhesive inspection window Krs are identical to the center coordinates of the flat area. The adhesive inspection window Krs is set so that its dimensions are slightly larger than the dimensions of the flat area occupied by the adhesive 6 in the data.

[0088] The determination process then uses the adhesive inspection window Krs to determine whether the entire area Ajs is sufficient. Specifically, the determination process determines whether a ratio of an area other than the entire area Ajs to the area of ​​the adhesive inspection window Krs exceeds a predetermined reference value. If the ratio is equal to or less than the reference value, the application state of the adhesive 6 alone is determined to be "good." If the ratio is greater than the reference value, the application state of the adhesive 6 alone is determined to be "poor."

[0089] The determination process also determines whether or not a positional relationship between the adhesive 6 and the solder 4 is appropriate. More specifically, the determination process calculates an area of ​​overlap between the solder area Ajh and the entire area Ajs and determines whether the area of ​​this overlap exceeds a predetermined area reference value set in advance (as shown in Fig. 19). If the area of ​​overlap exceeds the area reference value and thus it is determined that the positional relationship between the adhesive 6 and the solder 4 is insufficient, the determination process determines that the application state of the adhesive 6 is "poor" with respect to the positional relationship with the solder 4. In this case, the application state of the solder 4 is also determined to be "poor." On the other hand, if the area of ​​overlap is equal to or smaller than the area reference value and thus it is determined that the positional relationship between the adhesive 6 and the solder 4 is sufficient, the determination process determines that the application state of the adhesive 6 is "good" with respect to the positional relationship with the solder 4.

[0090] In addition, the determination process determines whether or not the positional relationship between the adhesive 6 and the electrode portion area Adh is appropriate. More specifically, the determination process calculates an area of ​​overlap between the entire area Ajs and the electrode portion area Adh and determines whether the area of ​​this overlap exceeds a predetermined area reference value set in advance (as shown in Fig. 20). If the overlap area exceeds the area reference value and thus it is determined that the positional relationship between the adhesive 6 and the electrode portion area Adh is insufficient, the determination process determines that the application state of the adhesive 6 is "poor" with respect to the positional relationship with the planned location area of ​​the electrode portion 5a. On the other hand, if the overlap area is equal to or smaller than the area reference value and thus it is determined that the positional relationship between the adhesive 6 and the electrode portion area Adh is sufficient, the determination process determines that the application state of the adhesive 6 is "good" with respect to the positional relationship with the planned location area of ​​the electrode portion 5a.

[0091] If all of the results of the respective determinations described above are "good," the determination process determines that the application state of the adhesive 6 is "good." On the other hand, if the result of at least one of the determinations described above is "bad," the determination process determines that the application state of the adhesive 6 is "bad."

[0092] According to the embodiment, the above-described good / poor quality assessment of the adhesive 6 is performed for all the portions of the adhesive 6 on the printed circuit board 1. If any of the respective portions of the adhesive 6 are determined to be "poor," the control device 33 determines that the printed circuit board 1 is "defective." If the printed circuit board 1 is determined to be "defective," the printed circuit board 1 is separated from the branching device into the above-described defect storage unit.

[0093] As described in detail above, the configuration of the embodiment specifies the center portion area Ajsa by using hue H and specifies the base portion area Ajsb by using saturation S. This configuration separately specifies the center portion area Ajsa and the base portion area Ajsb, each having different optical properties, through different specification procedures. This specifies both of the areas with high accuracy, and an area occupied by the adhesive 6 (the entire area Ajs) can be specified with higher accuracy. This improves the accuracy of judging the good / poor quality of the adhesive 6.

[0094] The center portion specifying module 337a extracts the red color range from the color tone image when specifying the center portion range Ajsa. Thus, the center portion range Ajsa of the commonly and frequently used red adhesive 6 can be specified more accurately and easily.

[0095] Furthermore, the root portion specifying module 337b extracts the low saturation area from the saturation image when specifying the root portion area Ajsb. This allows the root portion area Ajsb (root portion 6b) affected by the green resist area 7 as the basis for relatively low saturation to be specified more accurately and easily.

[0096] In addition, the foot section specification process performs the process of excluding the area related to the screen print 8. This more reliably prevents the area related to the screen print 8 from being mistakenly specified as the area related to the adhesive 6 (foot section area Ajsb or entire area Ajs). In this way, the area related to the adhesive 6 can be specified more accurately.

[0097] The present disclosure is not limited to the description of the above embodiment, but can be implemented, for example, by the configurations described below. Of course, the present disclosure can also be implemented by applications and modifications other than those shown below.

[0098] (a) According to the above-described embodiment, the center portion specifying module 337a is configured to extract the red color region from the color tone image based on the RGB luminance image when the center portion region Ajsa is specified. However, according to a modification, the center portion specifying module 337a may be configured to extract a region with higher luminances than a predetermined luminance reference value from a red luminance image based on the RGB luminance image when the center portion region Ajsa is specified. In this modification, the center portion specifying process is performed as described below.

[0099] As in Fig. 21, the center portion specifying process in step S31 first uses the RGB luminance image obtained from the camera 322 to obtain a red luminance image with respect to the inspection target area of ​​the circuit board 1. More specifically, the center portion specifying process extracts only the parameter values ​​of R among the respective parameter values ​​with respect to R, G, and B in the RGB luminance image to obtain the red luminance image. Fig. Figure 22 shows an example of the red luminance image. In the red luminance image, the central section 6a is relatively bright with relatively high parameter values ​​of R. In the red luminance image, the screen print 8 is also relatively bright.

[0100] Subsequently, in step S32, the center portion specifying process processes the red luminance image through a binarization process using a predetermined luminance reference value, thereby obtaining a binarized red luminance image. Fig. Figure 23 shows an example of the binarized red luminance image. The binarized red luminance image is a black and white image with 0 (bright part) and 1 (dark part). In this image, not only the central section 6a but also the screen print 8 is a bright part.

[0101] In step S33, the center portion specifying process then performs a screen printing area exclusion process to exclude an area related to the screen printing 8 from the binarized red luminance image. The screen printing area exclusion process first obtains a saturation image (see Fig. 12) based on the RGB luminance image to extract a particularly low saturation area from the RGB luminance image in step S331. In the saturation image, while the central portion 6a or the like with relatively high saturation is bright, the screen print 8 with relatively low saturation is dark.

[0102] Subsequently, in step S332, the screen printing area exclusion process processes the obtained saturation image through a binarization process using a predetermined saturation reference value, thereby obtaining a binarized saturation image. Fig. Figure 24 shows an example of a binarized saturation image. The binarized saturation image is a black and white image with 0 (bright part) and 1 (dark part) and is stored in the image storage section 342a. In the binarized saturation image, while the central portion 6a is a bright part, the silkscreen 8 is a dark part.

[0103] In step S333, the screen print area exclusion process calculates a logical AND operation of the obtained binarized red luminance image and the obtained binarized saturation image to exclude the area related to the screen print 8 from the binarized red luminance image. The center portion specification process accordingly obtains a center portion extraction image (see Fig. 25). This center-portion extraction image is a black-and-white image with 0 (bright part) and 1 (dark part), like the center-portion extraction image of the embodiment described above. The bright part of the center-portion extraction image is specified as the center-portion area Ajsa.

[0104] (b) The above embodiments and (a) are configured to perform the process of excluding the area related to the screen print 8 in the case of specifying the center portion area Ajsa or in the case of specifying the foot portion area Ajsb. However, a modification may be configured to perform a process of excluding the area related to the screen print 8 in the case of specifying the entire area Ajs.

[0105] In this modification, the center portion specifying process does not need to perform the process of excluding the area related to the screen print 8, unlike the configuration of (a) described above. Accordingly, the center portion specifying module 337a obtains a binarized red luminance image (see Fig. 23), which contains the center section area Ajsa and the area related to the screen print 8 and which enables the specification of the center section area Ajsa. The foot section specification module 337b receives a binarized inverse saturation image (see Fig. 14), which contains the foot section area Ajsb and the area related to the screen print 8 and which allows to specify the foot section area Ajsb.

[0106] The entirety specifying module 337c then calculates a logical AND of the binarized red luminance image obtained by the center portion specifying module 337a and the binarized inverse saturation image obtained by the foot portion specifying module 337b, thereby obtaining an adhesive and screen printing extraction image. Fig. Figure 26 shows an example of the adhesive and screen print extraction image. This image includes not only the entire area Ajs but also the area related to the screen print 8. The entirety specification module 337c performs a process of excluding the area related to the screen print 8 (screen print area exclusion process) to specify the entire area Ajs alone.

[0107] The screen printing area exclusion process first performs a process in which only the area related to the screen printing 8 is extracted. As in Fig. 27, the screen printing area exclusion process first acquires a reverse saturation image (in Fig. 13) based on the RGB luminance image in step S41 and a binarized inverse saturation image (in Fig. 14) in step S42. In the binarized reverse saturation image, the area related to the screen print 8 is a bright part.

[0108] The screen printing area exclusion process then produces a brightness image (see Fig. 28) based on the RGB luminance image in step S43. In step S44, the screen printing area exclusion process then processes the brightness image obtained in step S43 through a binarization process using a predetermined brightness reference value, thereby obtaining a binarized brightness image (in Fig. 29). The brightness reference value is determined based on the brightnesses of the central portion 6a and the screen print 8 in the brightness image. In the binarized brightness image, the area related to the screen print 8 is a bright part, as in the binarized reverse saturation image. The processing of steps S43 and S44 may be performed before or in parallel with the processing of steps S41 and S42.

[0109] In step S45, the screen printing area exclusion process then calculates a logical AND operation of the binarized inverse saturation image obtained in step S42 and the binarized brightness image obtained in step S44, and thereby obtains a screen printing image (in Fig. 30), in which only the area 8 related to the screen print 8 is extracted. In the screen print image, a process may additionally be performed to enlarge the area related to the screen print 8. Through this additional process, the area related to the screen print 8 can be more reliably excluded.

[0110] In steps S46 and S47, the screen printing area exclusion process excludes the area related to the screen printing 8 from the adhesive and screen printing extraction image to obtain an adhesive extraction image containing only the entire area Ajs. In step S46, the screen printing area exclusion process first reverses the screen printing image obtained in step S45 to obtain a reverse screen printing image (see Fig. 31). In the reverse screen printing image, the area related to the screen print 8 is a dark part. In step S47, the screen printing area exclusion process calculates a logical AND operation of the adhesive and screen print extraction image and the reverse screen print image to exclude the area related to the screen print 8 from the adhesive and screen print extraction image. The screen printing area exclusion process accordingly obtains an adhesive extraction image (see Fig. 32). The entirety specifying module 337c specifies a bright part of the obtained adhesive extraction image as the entire area Ajs.

[0111] (c) The exclusion of the area related to the screen print 8 in the case of the white screen print 8 is described in the above embodiment and in (b). In the case of the yellow screen print 8, the area related to the screen print 8 can be excluded by a procedure described below. The procedure obtains a tone image from the RGB luminance image and specifies (extracts) a yellow area in this tone image to obtain a screen print image that extracts the area related to the screen print 8. The procedure then uses this screen print image (e.g., calculates a logical AND operation of the adhesive and screen print extraction image described above and an inverse image of this screen print image) to exclude the area related to the screen print 8.

[0112] (d) According to the above-described embodiment, the center portion specifying module 337a (the center portion specifying process) does not perform the process of excluding the area related to the screen print 8 in the case of specifying the center portion area Ajsa from the color tone image. According to a modification, the screen print area exclusion process described in (a) or (b) above may be performed even when the center portion area Ajsa is specified from the color tone image.

[0113] (e) According to the embodiment described above, the root portion specifying module 337b is configured to exclude the area related to the screen print 8 from the binarized reverse saturation image when specifying the root portion area Ajsb.

[0114] However, according to a modification, the foot portion specifying module 337b may be configured to select a region adjacent to the center portion region Ajsa specified by the center portion specifying module 337a or a region located around the center portion region Ajsa from the region with respect to the foot portion 6b and with respect to the screen print 8 (light parts in Fig. 14) in the binarized inverse saturation image as the root portion area Ajsb. Configuring this modification also allows for more accurate and easier specification of the root portion area Ajsb.

[0115] (f) The above embodiment and (a) are configured to specify the center portion area Ajsa using the hue H or the red luminance. However, a modification may be configured to specify the center portion area Ajsa using the value V (e.g., the value shown in Fig. 28). This is because the central portion 6a is likely to have relatively large differences in the value V, the hue H, and the red luminance (the parameter value of R among the respective parameter values ​​with respect to R, G, and B) compared to the foot portion 6b and the resist region 7.

[0116] The above embodiment is configured to specify the footer portion area Ajsb using the saturation S. However, a modification may be configured to specify the footer portion area Ajsb using the hue H (e.g., the hue image of Fig.9). This is because the foot section 6b is likely to exhibit relatively large differences in saturation S and hue H compared to the middle section 6a and the resist area 7.

[0117] In the case of using the hue H to specify the center portion area Ajsa and the foot portion area Ajsb, respectively, a modification may be configured to use a different hue reference value for each specification object and specify the center portion 6a (the center portion area Ajsa) or the foot portion 6b (the foot portion area Ajsb). Accordingly, applying different specification procedures to specify the center portion area Ajsa and to specify the foot portion area Ajsb means applying different conditions to specify the center portion area Ajsa and to specify the foot portion area Ajsb based on the different optical properties of the center portion area Ajsa and the foot portion area Ajsb: e.g.Using different elements (hue H, saturation S, value V, and red luminance) to specify the center section area Ajsa and the foot section area Ajsb; or using different reference values ​​to specify the center section area Ajsa and the foot section area Ajsb.

[0118] (g) According to the above-described embodiment, the respective ring lights 321a, 321b, and 321c are configured to emit white light. However, according to a modification, the respective ring lights 321a, 321b, and 321c may be configured to emit red light, blue light, and green light (i.e., different light colors), respectively. In this modification, the camera 322 may be configured by a monochromatic camera to capture an image of the printed circuit board 1 each time the light is sequentially emitted from each of the ring lights 321a, 321b, and 321c, thus obtaining three different images. The hue image, the saturation image, and the like can be obtained based on these three different images. In these three different images, the parameter value for R (red color), the parameter value for G (green color), and the parameter value for B (blue color) are respectively set corresponding to each of the pixels.Accordingly, these three different images correspond to the “RGB luminance image”. List of reference symbols

[0119] 1... Printed circuit board (PCB), 6... Adhesive, 7... Resist area, 8... Silk screen, 13... PCB inspection device, 322... Camera (Imaging unit), 337a... Middle section specification module (Middle section specification unit), 337b... Foot section specification module (Foot section specification unit), 337c... Entirety specification module (Entirety specification unit), 337d... Determination module (Determination unit), Ajs... Entire area, Ajsa... Middle section area, Ajsb... Foot section area QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 6 262 378 B

[0004] JP H06-347 419 A

[0004]

Claims

[1] A printed circuit board inspection apparatus configured to perform an inspection of an adhesive applied to the printed circuit board, the printed circuit board inspection apparatus comprising: - an imaging unit configured to take an image of at least one area in the circuit board where the adhesive is applied; - a center portion specifying unit configured to specify a center portion area of ​​the adhesive in a captured image obtained by the imaging unit; - a foot portion specifying unit configured to specify a foot portion region of the adhesive located around the center portion region in the captured image using a specification procedure different from a specification procedure of the center portion region by the center portion specifying unit; - an entirety specifying unit configured to specify an entire area of ​​the adhesive based on the middle section area specified by the middle section specifying unit and the foot section area specified by the foot section specifying unit; and - a determination unit configured to perform a good / poor quality judgment with respect to the adhesive based on the entire range specified by the entirety specification unit. [2] Printed circuit board inspection device according to claim 1, wherein - the adhesive is red in color, and - the center portion specifying unit is configured to extract a red color region from a color tone image based on the captured image or to extract a region having a luminance higher than a predetermined luminance reference value from a red luminance image based on the captured image, in a process of specifying the center portion region. [3] Printed circuit board inspection device according to claim 1 or 2, wherein - the circuit board has a green resist area, - the adhesive is red in colour and is applied to the resist area, and - the foot portion specifying unit is configured to extract a region with lower saturation than a predetermined saturation reference value from a saturation image based on the captured image in a process of specifying the foot portion region. [4] Printed circuit board inspection device according to one of claims 1 to 3, wherein - at least one of the center portion specifying unit, the foot portion specifying unit, and the entirety specifying unit is configured to perform a process of excluding an area related to a screen printing provided on the printed circuit board from a corresponding area that is finally specified. [5] A printed circuit board inspection method for performing an inspection of an adhesive applied to a printed circuit board, the printed circuit board inspection method comprising: - an imaging process for taking an image of at least one area in the circuit board where the adhesive is applied; - a center portion specifying process for specifying a center portion area of ​​the adhesive in a captured image obtained by the imaging process; - a foot portion specifying process for specifying a foot portion region of the adhesive located around the center portion region in the captured image by a specification procedure different from a specification procedure of the center portion region by the center portion specifying process; - an entirety specifying process for specifying an entire area of ​​the adhesive based on the center portion area specified by the center portion specifying process and the foot portion area specified by the foot portion specifying process; and - a determination process for performing a good / poor quality assessment of the adhesive using the entire range specified by the entire specification process.

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