Substrate inspection apparatus and substrate inspection method

Abstract

Provided are a substrate inspection device and the like capable of achieving an improvement in yield and capable of appropriately detecting foreign matter that can cause a functional problem of a printed board. In the inspection of a printed board (1), first, an image of an inspection region in the printed board (1) including a component mounting region (Ma) and larger than the component mounting region (Ma), which is a region corresponding to a mounting position of a component with respect to the printed board (1), is acquired. Then, foreign matter (X) in the inspection region is detected from the acquired image. On this basis, the detected foreign matter (X) is not immediately determined to be defective, but is determined to be good or bad based on a positional relationship of the foreign matter (X) with respect to the component mounting region (Ma). Therefore, even if foreign matter (X) is detected, in a case where it is considered that a functional problem of the printed board (1) will not occur based on the positional relationship of the foreign matter (X) with respect to the component mounting region (Ma), the foreign matter (X) can not be determined to be defective.

Description

Technical Field

[0001] This invention relates to a substrate inspection apparatus and a substrate inspection method for inspecting printed circuit boards. Background Technology

[0002] The printed circuit board includes a flat substrate, circuit patterns and pads formed on the surface of the substrate, and an insulating resist coating the surface of the substrate other than the pads.

[0003] Generally, in a substrate production line for mounting components onto a printed circuit board (PCB), solder paste is first printed onto the pads (solder printing process). Next, the components are temporarily fixed to the PCB based on the adhesive properties of the solder paste (mounting process). Afterward, the PCB is guided to a reflow oven where the solder paste is heated and melted for soldering (reflow process).

[0004] Typically, in such a substrate production line, foreign objects in the printed substrate are detected based on images obtained by photographing the printed substrate with printed solder paste.

[0005] As a method for detecting foreign objects, a method has been proposed that involves photographing the printed circuit board of the object to be inspected to obtain an image, and comparing the acquired image with an image of a standard substrate (main substrate) to detect foreign objects (e.g., see Patent Document 1). According to this method, foreign objects present on the printed circuit board can be easily detected. Furthermore, Patent Document 1 describes the exclusion of holes and circuit patterns from the object to be inspected.

[0006] In addition, as another method for detecting foreign objects, there is a known method that sets a region corresponding to the mounting position of the component and which needs to be checked for foreign objects as a foreign object inspection area, performs image processing on the set foreign object inspection area as the object, and thereby detects whether there are foreign objects in the foreign object inspection area (for example, see Patent Document 2, etc.). According to this method, only the area that specifically needs to be checked for foreign objects is processed as the object, thus reducing the processing load.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2017-125861;

[0010] Patent document 2: Japanese Patent Application Publication No. 2018-113467. Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, when foreign objects are present on the printed circuit board (PCB), depending on their location, defects such as short circuits between multiple pads may occur due to the foreign object (e.g., hair carbonized during reflow oven heating), causing functional problems with the PCB. On the other hand, even when foreign objects are present on the PCB, if they are placed in an insulating resist and are sufficiently separated from the pads, functional problems with the PCB caused by the foreign object may not sometimes occur.

[0013] Regarding this point, in the method described in Patent Document 1 above, although holes and circuit patterns are excluded from the inspection objects as needed, the entire area in the image is basically treated as the object for foreign object detection. Therefore, even if a foreign object is present in a location that will not cause functional problems to the printed circuit board, the printed circuit board will be deemed unqualified on the grounds of detecting the foreign object, which may result in a decrease in yield.

[0014] On the other hand, in the method described in Patent Document 2 above, the presence or absence of foreign objects is detected by targeting the foreign object inspection area. Therefore, it is possible to prevent the printed circuit board from being deemed defective due to foreign objects located in areas that will not cause functional problems. However, even when the foreign object is relatively large, Figure 18 The slight overlap between foreign object X (as shown) and the foreign object inspection area Ar can also cause functional problems in the printed circuit board due to this foreign object X. Regarding this point, in the method described in Patent Document 2, when a foreign object in this state is present, the area occupied by the foreign object in the foreign object inspection area is very small, so it is possible that the foreign object is not detected or is overlooked. Therefore, even though a foreign object exists that causes functional problems in the printed circuit board, it is possible to mistakenly classify the printed circuit board being inspected as a qualified product.

[0015] The present invention was made in view of the above circumstances, and its object is to provide a substrate inspection apparatus that can improve the yield rate and properly detect foreign objects that may cause functional problems to printed circuit boards.

[0016] Methods for solving problems

[0017] The following sections provide a detailed explanation of each solution suitable for achieving the aforementioned objectives. Additionally, the specific effects of each solution will be noted as needed.

[0018] Solution 1: A substrate inspection apparatus for inspecting a printed circuit board with solder paste printed on it, characterized in that it comprises:

[0019] The image acquisition unit is capable of acquiring an image of a defined inspected area in the printed circuit board that includes a component mounting area and is larger than the component mounting area, wherein the component mounting area is the area corresponding to the mounting position of the component relative to the printed circuit board;

[0020] The foreign object detection unit detects foreign objects in the inspected area based on an image acquired by the image acquisition unit; and

[0021] The good / bad determination unit determines the good or bad of a foreign object based on the positional relationship between the foreign object detected by the foreign object detection unit and the component mounting area.

[0022] Furthermore, the "component mounting area" refers to an area that includes "the area where components may be mounted," exposed pads not covered by resist, and the area containing solder paste or adhesive. However, the "component mounting area" is not limited to the minimum area containing "the area where components may be mounted," pads, and solder paste or adhesive; it can be an area that appropriately expands the minimum area to account for the movement of foreign objects, etc.

[0023] Furthermore, "the area where components may be mounted" basically refers to "the reference mounting position of the component," but when using self-alignment, it is defined as an area that includes the predetermined mounting position of the component that is offset corresponding to the self-alignment. In addition, "the reference mounting position of the component" can be strictly set using design information and manufacturing information, or it can be simply set using the position of pads, etc.

[0024] According to Scheme 1 above, firstly, the foreign object detection unit detects foreign objects in a large area (the area to be inspected), including the component mounting area. Furthermore, when a foreign object is detected, it is not immediately deemed unqualified; instead, the good or bad condition of the foreign object is determined by the good or bad condition determination unit based on its positional relationship with the component mounting area.

[0025] Therefore, even if a foreign object is detected, it can be excluded from being deemed a defective component if it is determined that the foreign object will not cause functional problems to the printed circuit board based on its positional relationship with the component mounting area. This allows for more reliable prevention of printed circuit board defects caused by foreign objects deemed not to cause functional problems. Consequently, the number of printed circuit boards rejected due to defects can be reduced, thereby improving yield.

[0026] On the other hand, if a detected foreign object is deemed to cause functional problems on the printed circuit board based on its positional relationship with the component mounting area, the foreign object can be determined as non-conforming. Therefore, by properly detecting foreign objects that could cause functional problems on the printed circuit board, it is possible to more reliably prevent the printed circuit board from being mistakenly determined as a qualified product.

[0027] Solution 2: According to the substrate inspection device of Solution 1, the good or bad determination unit is configured to determine that the foreign object is unqualified if the foreign object detected by the foreign object detection unit overlaps or is in contact with the component mounting area.

[0028] According to Scheme 2 above, it is easier to determine whether a foreign object is a defective foreign object that could cause functional problems to the printed circuit board. Therefore, the burden of the determination process can be reduced.

[0029] Solution 3: The substrate inspection apparatus according to Solution 1 or 2, characterized in that,

[0030] It has a display unit capable of displaying information.

[0031] The display unit is configured to at least display an image showing the positional relationship between the foreign object detected by the foreign object detection unit and the component mounting area.

[0032] According to Scheme 3 above, the positional relationship between detected foreign objects and component installation areas can be easily grasped visually. Therefore, it improves convenience related to confirming whether the inspection was appropriate (according to the target) and confirming / adjusting inspection conditions.

[0033] Option 4: A substrate inspection apparatus according to any one of Options 1 to 3, characterized in that,

[0034] The printed circuit board has a green resist area.

[0035] The image acquisition unit is configured to use multiple colored lights to acquire a color image of the inspected area.

[0036] The substrate inspection device further includes:

[0037] A resist area information acquisition unit acquires resist area information for determining the extent of the resist area in the printed circuit board; and

[0038] The hue image acquisition unit uses the color image acquired by the image acquisition unit to obtain the hue image of the inspected area.

[0039] The foreign object detection unit is configured to detect foreign objects in at least the resist region determined by the resist region information of the hue image by means of a hue difference relative to the resist region.

[0040] Foreign objects containing brown or blonde hair are less likely to show differences in brightness and chroma compared to the green resist area. However, they are more likely to show differences in hue compared to the green resist area. Utilizing this, according to the above-described scheme 4, foreign objects can be detected by using the hue difference between the foreign object and the resist area in at least one resist area of ​​the hue image. Therefore, brown or blonde hair located in the resist area can be detected with high precision, thereby improving the detection capability of foreign objects.

[0041] Option 5: A substrate inspection apparatus according to any one of Options 1 to 4, characterized in that,

[0042] The printed circuit board has a green resist area.

[0043] The image acquisition unit is configured to use multiple colored lights to acquire a color image of the inspected area.

[0044] The substrate inspection device further includes:

[0045] A resist area information acquisition unit acquires resist area information for determining the extent of the resist area in the printed circuit board; and

[0046] The chroma image acquisition unit uses the color image acquired by the image acquisition unit to obtain the chroma image of the inspected region.

[0047] The foreign object detection unit is configured to detect foreign objects by utilizing the chroma difference relative to the resist region in at least the resist region region of the chroma image determined by the resist region information.

[0048] Hair, such as black or white hair, is particularly prone to chroma differences relative to the green resist area in foreign matter. Utilizing this, according to scheme 5 above, foreign matter is detected by using the chroma difference relative to the resist area. Therefore, black or white hair located in the resist area can be detected with high precision, thereby further improving the detection capability of foreign matter.

[0049] Alternatively, the structures of schemes 4 and 5 above can also be used. That is, it can also be configured to detect foreign objects using both the hue image and the chroma image of the area being inspected. In this case, it is possible to detect hair of commonly known colors such as black, white, brown, or blonde with high accuracy.

[0050] Solution 6: A substrate inspection method for inspecting a printed circuit board with solder paste printed on it, the method being characterized by comprising:

[0051] The image acquisition process is capable of acquiring an image of a defined inspected area in the printed circuit board that includes a component mounting area and is larger than the component mounting area, wherein the component mounting area is the area corresponding to the mounting position of the component relative to the printed circuit board;

[0052] The foreign object detection process detects foreign objects in the inspected area based on an image acquired by the image acquisition process; and

[0053] The good / bad determination process determines the quality of the foreign object based on its positional relationship with the component mounting area as detected by the foreign object detection process.

[0054] According to the above scheme 6, the same effect as that of scheme 1 can be achieved.

[0055] Solution 7: The substrate inspection method according to Solution 6 is characterized in that, in the good / bad determination process, if a foreign object detected by the foreign object detection process overlaps or is in contact with the component mounting area, the foreign object is determined to be unqualified.

[0056] According to Scheme 7 above, the same effect as Scheme 2 above can be achieved. Attached Figure Description

[0057] Figure 1 This is a schematic plan view of a printed circuit board.

[0058] Figure 2 This is a partially enlarged cross-sectional schematic diagram of the printed circuit board.

[0059] Figure 3 This is a block diagram showing the structure of a printed circuit board production line.

[0060] Figure 4 This is a schematic diagram showing the general structure of a solder printing post-inspection device.

[0061] Figure 5 This is a block diagram showing the functional structure of the solder printing post-inspection device.

[0062] Figure 6 It is a simplified diagram representing the color wheel of the HSV color space.

[0063] Figure 7 This is a schematic diagram showing the mounting area of ​​components, etc.

[0064] Figure 8 This is a schematic diagram showing the mounting area of ​​components, etc.

[0065] Figure 9 It is a diagram showing the hue image of the inspected substrate with gold pigment attached.

[0066] Figure 10 It is a diagram showing the hue image of the inspected substrate with attached tea hair.

[0067] Figure 11 This is a graph representing the chroma image of the substrate being inspected, which has black hair attached to it.

[0068] Figure 12 This is a colorimetric image representing the substrate being inspected, which has white hair attached to it.

[0069] Figure 13 This is a schematic diagram representing foreign objects or similar items that overlap with the component's mounting area and are therefore deemed unqualified.

[0070] Figure 14 This is a schematic diagram representing foreign objects or similar items that are deemed unqualified due to their contact with the component's mounting area.

[0071] Figure 15 This is a schematic diagram representing the image displayed in other embodiments.

[0072] Figure 16 This is a schematic diagram used to illustrate a method for determining the quality of foreign objects in other embodiments.

[0073] Figure 17 This is a schematic diagram used to supplement the explanation of the method for determining the quality of foreign objects in other embodiments.

[0074] Figure 18 This is a schematic diagram illustrating a method for detecting foreign objects in the prior art. Detailed Implementation

[0075] Hereinafter, one embodiment will be described with reference to the accompanying drawings. First, the structure of the printed circuit board 1 will be described.

[0076] like Figure 1 , Figure 2 As shown, the printed circuit board 1 has a circuit pattern 3a made of copper foil, pads 3b, and through holes 3c of the pads 3b extending through the surface and back of the substrate 2, formed on a flat substrate 2 made of glass epoxy resin or the like. A paste solder 5, made by mixing solder particles with flux, is printed on the pads 3b and through holes 3c. This results in an electrode portion (e.g., an electronic component, not shown in the figure) being electrically connected to the pads 3b via the paste solder 5.

[0077] In addition, a green resist area 4 is provided on the surface of the substrate 2, excluding the pads 3b. Figure 1 (The area is represented by a scattered pattern). The resist area 4 is composed of an insulating resist and is coated on the substrate 2 and the circuit pattern 3a. In addition, an adhesive for fixing the components is applied to the printed circuit board 1 as needed.

[0078] Next, refer to Figure 3 The production line (manufacturing process) for manufacturing printed circuit board 1 is described. For example... Figure 3 As shown, in production line 10, from its upstream side ( Figure 3 Starting from the top, a solder printing machine 12, a solder printing post-inspection device 13, a component mounting machine 14, a reflow device 15, and a reflow post-inspection device 16 are arranged in sequence. The printed circuit board 1 is configured to be transported relative to these devices in the above order. In this embodiment, the solder printing post-inspection device 13 constitutes a "board inspection device".

[0079] The solder printing machine 12 performs a solder printing process to print paste solder 5 onto each pad 3b of the printed circuit board 1. For example, the paste solder 5 is printed by screen printing. In screen printing, paste solder 5 is first supplied to the upper surface of the screen mask while the lower surface of the screen mask is in contact with the printed circuit board 1. The screen mask has a plurality of openings corresponding to each pad 3b of the printed circuit board 1. Next, a predetermined squeegee is brought into contact with and moved on the upper surface of the screen mask, thereby filling the openings with paste solder 5. Then, by moving the printed circuit board 1 away from the lower surface of the screen mask, paste solder 5 is applied to the pads 3b and filled into the through-holes 3c.

[0080] The solder printing post-inspection device 13 performs a solder printing post-inspection process to check the state of the printed solder paste 5 and whether there are foreign objects on the printed circuit board 1. The solder printing post-inspection device 13 will be described in more detail later.

[0081] The component mounting machine 14 performs a component mounting process (assembly process) on pads 3b or the like, on which solder paste 5 is printed. Here, the electrode portions of the component are temporarily fixed to the prescribed solder paste 5. Furthermore, the component mounting machine 14 can adjust the mounting position of the component according to the position of the printed solder paste 5.

[0082] The reflow apparatus 15 performs a reflow process in which the solder paste 5 is heated and melted to solder the pad 3b to the electrode portion of the component (soldering).

[0083] The reflow inspection device 16 performs a reflow inspection process to check whether the soldering, etc., was performed properly during the reflow process. For example, image data of the printed circuit board 1 after the reflow process is used to check whether the components have positional misalignment, etc.

[0084] Thus, in production line 10, while the printed circuit board 1 is being transported in sequence, the solder printing process → solder printing post-inspection process → component installation process (assembly process) → reflow process → reflow post-inspection process are carried out.

[0085] In addition, although not shown in the drawings, a conveyor or the like for transporting the printed board 1 is provided between the above-described devices such as between the solder printer 12 and the post-solder-printing inspection device 13 in the production line 10. Further, a branch device is provided on the downstream side between the post-solder-printing inspection device 13 and the component mounter 14 and on the downstream side of the post-reflow inspection device 16. The printed board 1 determined to be a non-defective product by the post-solder-printing inspection device 13 and the post-reflow inspection device 16 is directly guided to the downstream side. On the other hand, the printed board 1 determined to be a defective product by the inspection devices 13 and 16 is discharged to a defective-product storage section (not shown in the drawings) through the branch device.

[0086] Next, Figure 4 and Figure 5 the structure of the post-solder-printing inspection device 13 will be described.

[0087] As Figure 4 and Figure 5 shown, the post-solder-printing inspection device 13 includes: a transport mechanism 31 that transports and positions the printed board 1; an inspection unit 32 for inspecting the printed board 1; and a control device 33 (see Figure 5 ), which performs various controls, image processing, and arithmetic processing in the post-solder-printing inspection device 13, including driving control of the transport mechanism 31 and the inspection unit 32.

[0088] The transport mechanism 31 includes: a pair of transport rails 31a arranged along the loading / unloading direction of the printed board 1; and an annular conveyor belt 31b rotatably disposed on each transport rail 31a. In addition, although not shown in the drawings, a drive unit such as a motor for driving the conveyor belt 31b and a chuck mechanism for positioning the printed board 1 at a predetermined position are provided in the transport mechanism 31. The transport mechanism 31 is driven and controlled by the control device 33 (a transport mechanism control unit 343 described later).

[0089] In the above structure, both side edge portions in the width direction orthogonal to the loading / unloading direction of the printed board 1 transported into the post-solder-printing inspection device 13 are inserted into the transport rails 31a and placed on the conveyor belt 31b. Next, the conveyor belt 31b starts to operate, and the printed board 1 is transported to a predetermined inspection position. When the printed board 1 reaches the inspection position, the conveyor belt 31b stops, and the chuck mechanism operates. By the operation of the chuck mechanism, the conveyor belt 31b is pushed upward, and a state is formed in which both side edge portions of the printed board 1 are clamped by the conveyor belt 31b and the upper edge portions of the transport rails 31a. Thereby, the printed board 1 is positioned and fixed at the inspection position. When the inspection is completed, the fixing by the chuck mechanism is released, and the conveyor belt 31b starts to operate. Thereby, the printed board 1 is transported out of the post-solder-printing inspection device 13. Of course, the structure of the transport mechanism 31 is not limited to the above-described method, and other structures may also be adopted.

[0090] The inspection unit 32 is disposed above the transport track 31a (the transport path of the printed circuit board 1). The inspection unit 32 includes a lighting device 321 and a camera 322. Additionally, the inspection unit 32 is equipped with a camera capable of moving along the X-axis (…). Figure 4 The X-axis moving mechanism 323, which can move in the left and right directions, and the Y-axis moving mechanism 323, which can move in the left and right directions. Figure 4 The Y-axis moving mechanism 324 moves in the forward and backward direction. The inspection unit 32 is driven and controlled by the control device 33 (the moving mechanism control unit 342 described later). In this embodiment, the lighting device 321 and the camera 322 constitute an "image acquisition unit".

[0091] The lighting device 321 illuminates the printed circuit board 1, which is to be inspected by the solder printing post-inspection device 13, with a predetermined light. More specifically, the lighting device 321 includes a first ring lamp 321a, a second ring lamp 321b, and a third ring lamp 321c.

[0092] The first ring lamp 321a illuminates the printed circuit board 1 to be inspected from a generally horizontal direction. The second ring lamp 321b is positioned above the first ring lamp 321a and illuminates the printed circuit board 1 to be inspected from an obliquely upward direction. The third ring lamp 321c is positioned inside the second ring lamp 321b and illuminates the printed circuit board 1 to be inspected from a generally vertical direction.

[0093] Each ring lamp 321a, 321b, and 321c irradiates white light onto the printed circuit board 1. That is, each ring lamp 321a, 321b, and 321c irradiates multiple colored lights, such as red, blue, and green light, onto the printed circuit board 1 at one time.

[0094] Camera 322 is configured with its optical axis aligned vertically (Z-axis direction) to capture images of a predetermined area to be inspected on the printed circuit board 1 from directly above. The area to be inspected is one of several areas pre-defined on the printed circuit board 1, with the camera 322's field of view (shooting range) as a unit. The area to be inspected includes the component mounting area Ma (described later) and is set to be larger than Ma. Furthermore, a portion of each area to be inspected is set to overlap with a portion of an adjacent area to be inspected.

[0095] Camera 322 is a color camera, and its operation is controlled by control device 33 (camera control unit 333 described later). Under the control of control device 33 (camera control unit 333), camera 322 captures the reflected light from printed circuit board 1 while simultaneously illuminating it from ring lights 321a, 321b, and 321c. This acquires a color image of the inspected area of ​​printed circuit board 1. This color image has multiple pixels, and each pixel is assigned three parameter values: R (red), G (green), and B (blue). In this embodiment, these parameter values ​​range from 0 to 1.

[0096] The color image captured by camera 322 is transmitted to control device 33 (color image acquisition unit 334 described later). Then, control device 33 performs inspection processing based on the color image. In this embodiment, the process of acquiring a color image by camera 322 is equivalent to an "image acquisition process".

[0097] The control device 33 is composed of a computer including a CPU (Central Processing Unit) that performs prescribed arithmetic operations, a ROM (Read Only Memory) that stores various programs, fixed-value data, etc., a RAM (Random Access Memory) that temporarily stores various data when performing various arithmetic operations, and their peripheral circuits.

[0098] The control device 33 operates according to various programs via the CPU, functioning as a main control unit 331, an illumination control unit 332, a camera control unit 333, a color image acquisition unit 334, a hue image acquisition unit 335, a chroma image acquisition unit 336, a resist area information acquisition unit 337, an installation area information acquisition unit 338, a foreign object detection unit 339, a good / bad judgment unit 340, a display control unit 341, a moving mechanism control unit 342, and a transport mechanism control unit 343. In this embodiment, the hue image acquisition unit 335 constitutes a "hue image acquisition unit," similarly, the chroma image acquisition unit 336 constitutes a "chroma image acquisition unit," the resist area information acquisition unit 337 constitutes a "resist area information acquisition unit," the foreign object detection unit 339 constitutes a "foreign object detection unit," and the good / bad judgment unit 340 constitutes a "good / bad judgment unit."

[0099] However, the various functional units mentioned above are implemented through the cooperation of various hardware components such as the CPU, ROM, and RAM. It is not necessary to explicitly distinguish between functions implemented in hardware or software. Some or all of these functions can also be implemented by hardware circuits such as ICs. In addition, the control device 33 has a functional unit for checking the state of the solder paste 5, but this functional unit is omitted in this embodiment.

[0100] Furthermore, the control device 33 is equipped with an input unit 344 consisting of a keyboard, mouse, touch panel, etc.; a display unit 345 consisting of a liquid crystal display and other components capable of displaying images; a storage unit 346 capable of storing various data, programs, calculation results, check results, etc.; and a communication unit 347 capable of sending and receiving various data with external devices. In this embodiment, the display unit 345 constitutes a "display unit". First, the storage unit 346 and the communication unit 347 will be described.

[0101] Storage unit 346 is composed of HDD (Hard Disk Drive), SSD (Solid State Drive), etc., and stores various information. Storage unit 346 includes image storage unit 346a, inspection information storage unit 346b, area information storage unit 346c, and inspection result storage unit 346d.

[0102] Image storage unit 346a stores color images captured by camera 322. Furthermore, image storage unit 346a also stores hue images and chroma images, which will be described later, acquired by hue image acquisition unit 335 or chroma image acquisition unit 336, respectively. The color images, hue images, and chroma images stored in image storage unit 346a can be appropriately displayed on display unit 345 via display control unit 341.

[0103] The inspection information storage unit 346b stores various information for inspecting the printed circuit board 1. For example, the inspection information storage unit 346b stores multiple thresholds (hue threshold, chroma threshold) for binarizing hue and chroma images, a reference value for determining whether a region is resist region 4 (region determination reference value), an area threshold for detecting foreign objects, and a length threshold, etc. In addition, the length threshold is set to a value equivalent to 100 μm, for example.

[0104] The area information storage unit 346c stores the resist area information acquired by the resist area information acquisition unit 337. Additionally, the area information storage unit 346c also stores component mounting area information acquired by the mounting area information acquisition unit 338.

[0105] The inspection result storage unit 346d stores data related to the foreign object detection results of the foreign object detection unit 339, and inspection result data related to the good or bad condition of the foreign object determined by the good or bad condition determination unit 340. In addition, the inspection result storage unit 346d also stores inspection result data related to the state of the solder paste 5, and statistical data after probability statistical processing of various inspection result data. This inspection result data and statistical data can be appropriately displayed on the display unit 345 via the display control unit 341.

[0106] Next, the various functional units constituting the control device 33 will be described in detail. First, the moving mechanism control unit 342 and the transport mechanism control unit 343 will be described, and then the main control unit 331 and the like will be described.

[0107] The movement mechanism control unit 342 is a functional unit that drives and controls the X-axis movement mechanism 323 and the Y-axis movement mechanism 324. It controls the position of the inspection unit 32 according to command signals from the main control unit 331. By driving and controlling the X-axis movement mechanism 323 and the Y-axis movement mechanism 324, the movement mechanism control unit 342 can move the inspection unit 32 to a position above any inspected area on the printed circuit board 1, which is fixed at the inspection position. Then, while sequentially moving the inspection unit 32 to multiple inspected areas set on the printed circuit board 1, it performs inspection of those inspected areas, thereby performing an inspection of the entire area of ​​the printed circuit board 1.

[0108] The transport mechanism control unit 343 is a functional unit that drives and controls the transport mechanism 31, and controls the transport position of the printed circuit board 1 that is to be inspected based on the command signal from the main control unit 331.

[0109] Next, the main control unit 331 will be described. The main control unit 331 is a functional unit responsible for the overall control of the solder printing post-inspection device 13, and is configured to receive and send various signals with other functional units such as the lighting control unit 332 and the camera control unit 333.

[0110] The lighting control unit 332 is a functional unit that drives and controls the lighting device 321. Based on the command signals from the main control unit 331, the lighting control unit 332 performs timing control and other functions related to the illumination or cessation of illumination of the printed circuit board 1 by the lighting device 321.

[0111] The camera control unit 333 is a functional unit that drives and controls the camera 322. The camera control unit 333 controls the timing of the camera 322's shooting of the printed circuit board 1 based on the command signals from the main control unit 331.

[0112] The color image acquisition unit 334 is a functional unit for acquiring color images captured by the camera 322. The color images acquired by the color image acquisition unit 334 are stored in the image storage unit 346a.

[0113] The hue image acquisition unit 335 uses a color image stored in the image storage unit 346a that is related to the inspected area of ​​the printed circuit board 1 to acquire a hue image of the inspected area of ​​the printed circuit board 1. The hue image is an image that represents the hue of each pixel in the color image in the hue circle of the HSV color space. Figure 9 , Figure 10 This represents an example of a hue image. The hue image acquisition unit 335 calculates the hue wheel of the HSV color space with 0° (360°) set to red, 60° set to yellow, 120° set to (strictly) green, 180° set to cyan, 240° set to blue, and 300° set to magenta (see reference). Figure 6 The hue (hereinafter referred to as "hue H") of each pixel in the image is determined by the hue of the pixel, and a hue image is obtained by associating each pixel with its hue H. In this embodiment, the process of obtaining the hue image of the printed circuit board 1 by the hue image acquisition unit 335 is equivalent to a "hue image acquisition process". The hue image is stored in the image storage unit 346a.

[0114] Hue H is calculated using the following mathematical formulas 1, 2, or 3. Formula 1 is used when the value of parameter B is the largest among the RGB parameters. Formula 2 is used when the value of parameter R is the largest among the RGB parameters. Formula 3 is used when the value of parameter G is the largest among the RGB parameters. However, hue H is not defined if the maximum and minimum values ​​of all RGB parameters are equal.

[0115] (Mathematical Formula 1) H = 60 × (GR) / (MAX - MIN) + 60

[0116] (Mathematical formula 2) H = 60 × (BG) / (MAX - MIN) + 180

[0117] (Mathematical Formula 3) H = 60 × (RB) / (MAX - MIN) + 300

[0118] In addition, in mathematical formulas 1 to 3, R, G, and B represent the values ​​of each parameter of RGB, MAX represents the maximum value among the parameter values, and MIN represents the minimum value among the parameter values.

[0119] The chroma image acquisition unit 336 uses a color image stored in the image storage unit 346a that is related to the inspected area of ​​the printed circuit board 1 to acquire a chroma image of the inspected area of ​​the printed circuit board 1. A chroma image is an image that represents the chroma of each pixel in a color image. Figure 11 , Figure 12 This is an example of a chroma image. The chroma image acquisition unit 336 calculates the chroma S (chroma in HSV form) of each pixel in the color image using the following mathematical formula 4, and acquires a chroma image that establishes a correlation between each pixel and its chroma S. In this embodiment, the process of obtaining the chroma image of the printed circuit board 1 by the chroma image acquisition unit 336 is equivalent to a "chroma image acquisition process". The chroma image is stored in the image storage unit 346a.

[0120] (Mathematical expression 4) S=(1-3×MIN / (R+G+B))

[0121] Similarly to equations 1 to 3, in equation 4, R, G, and B represent the values ​​of the RGB parameters, and MIN represents the minimum value among them. Furthermore, the chroma S of each pixel in a chroma image is represented by values ​​from 0 to 1; the closer the chroma S of a pixel is to 1, the closer its color is to the primary color. Alternatively, chroma S can be calculated using equation 4a below, instead of equation 4.

[0122] (Mathematical formula 4a) S=(MAX-MIN) / MAX

[0123] The resist area information acquisition unit 337 acquires resist area information for determining the extent occupied by the resist area 4 in the printed circuit board 1. In this embodiment, the resist area information acquisition unit 337 acquires the resist area information based on the printed circuit board 1 to be inspected.

[0124] More specifically, the resist area information acquisition unit 337 acquires the same hue image as described above based on the color image. Alternatively, the hue image acquired by the hue image acquisition unit 335 may also be used.

[0125] Next, the resist area information acquisition unit 337 performs processing to determine the connecting components of pixels in the hue image whose hue H is within a specified range (for example, 70° to 160° in this embodiment), and calculates the area (in this embodiment, the number of pixels) of the determined connecting components (block portions). That is, the resist area information acquisition unit 337 calculates the area of ​​block portions in the color image that are green or close to green.

[0126] Based on this, the resist area information acquisition unit 337 compares the area of ​​the block portion with the area determination reference value pre-stored in the inspection information storage unit 346b, and determines the block portion whose area exceeds the area determination reference value as resist area 4. Furthermore, the resist area information acquisition unit 337 acquires information used to determine the resist area 4 (e.g., coordinate information indicating the position of the resist area 4) as resist area information. The acquired resist area information is stored in the area information storage unit 346c. In this embodiment, the process of acquiring resist area information through the resist area information acquisition unit 337 is equivalent to a "resist area information acquisition process".

[0127] The mounting area information acquisition unit 338 acquires mounting area information for determining the "component mounting area" of the printed circuit board 1. The "component mounting area" refers to an area that includes "areas where components may be mounted," exposed pads 3b not covered by resist, and paste solder 5 or adhesive. Furthermore, "areas where components may be mounted" essentially refers to "reference mounting positions of components," but in the case of self-alignment, it includes predetermined mounting positions of components that are offset corresponding to self-alignment. Self-alignment refers to the action of the paste solder 5, molten during the reflow process, wetting and spreading along the surface of the pads 3b. Due to self-alignment, even when paste solder 5 is printed at a position offset from the pads 3b, the paste solder 5 is sometimes positioned almost perfectly on the pads 3b after the reflow process. Furthermore, the "reference mounting position of the component" can be strictly set using design information and manufacturing information, or it can be simply set using the position of the pads 3b, etc.

[0128] In this embodiment, for example, such as Figure 7 , Figure 8 As shown, the predetermined mounting positions of the components when the offset corresponding to the self-alignment is at its maximum are positions P1, P2, P3, and P4. Figure 7 , Figure 8 In the case of the position indicated by the medium-thick double-dotted line, the reference mounting position PB of the included component is... Figure 7 , Figure 8 The component mounting area Ma is defined as the rectangular area P1 to P4, including the pad 3b on which the component is mounted, and the area containing the solder paste 5. The "component mounting area" is not limited to a minimum area containing the area where the component may be mounted, the pad 3b, and the solder paste 5 or adhesive; it can be an area that appropriately expands upon the minimum area to accommodate the movement of foreign objects. Furthermore, in... Figure 7 , Figure 8 In the example, the "area where components may be installed" can be said to be the smallest area that includes positions P1 to P4 and the reference installation position PB.

[0129] In this embodiment, the mounting area information acquisition unit 338 uses, for example, information representing the positional relationship between the resist area information in the design and the component mounting area to acquire a range of coordinates (coordinates representing the position of pixels) that are in the same positional relationship as the acquired resist area information as mounting area information. Furthermore, the information representing the positional relationship is pre-stored in the inspection information storage unit 346b. The acquired mounting area information is stored in the area information storage unit 346c.

[0130] The foreign object detection unit 339 detects foreign objects in the resist region 4 determined by the resist region information in the hue or chroma image of the area to be inspected.

[0131] Foreign object detection based on hue image is performed using the hue difference relative to the resist region 4. Specifically, the foreign object detection unit 339 first obtains a binarized hue image, which is generated by binarizing each pixel in the hue image of the area to be inspected using its hue components. In this embodiment, the binarized hue image is obtained by comparing a hue threshold pre-stored in the inspection information storage unit 346b with the hue H of each pixel in the hue image, and then binarizing each pixel in the hue image. The resulting binarized hue image is a black and white image having 0 (bright areas) and 1 (dark areas). The binarized hue image is stored in the image storage unit 346a.

[0132] Additionally, for reference, a hue image of a printed circuit board 1 with blonde X1 attached is shown (see reference). Figure 9 ) and the hue image of the printed circuit board 1 with the brown hair X2 attached (see reference) Figure 10 As shown above, in the hue image, the hues of blonde X1 and brown X2, and the hue of resist region 4, are sufficiently different for inspection. Therefore, in the binarized hue image, for example, blonde X1 and brown X2 are represented as dark areas, and resist region 4 is represented as a bright area.

[0133] After obtaining the binarized hue image, the foreign object detection unit 339 sets the resist region 4 in the binarized hue image, which is at least determined by the resist region information obtained by the resist region information acquisition unit 337, as the inspection target (inspection range). Therefore, pads 3b, vias 3c, and text and graphic portions attached to the printed circuit board 1 are removed from the inspection target (inspection range). In addition, in this embodiment, the resist region information and the hue image are obtained based on the same printed circuit board 1 as the inspection target, so the optimal inspection target for the printed circuit board 1 is set.

[0134] Based on this, the foreign object detection unit 339 performs a process to determine the connecting components (e.g., dark areas) of pixels in the inspected object (inspection range) that have a hue different from that of the resist region 4 (e.g., bright areas), and calculates the area (e.g., number of pixels) of the determined connecting components (block portions). Additionally, the foreign object detection unit 339 also calculates the length (e.g., X-direction length and Y-direction length) of the connecting components (block portions).

[0135] Next, the foreign object detection unit 339 compares the area of ​​the block portion with an area threshold pre-stored in the inspection information storage unit 346b. Then, if the area of ​​the block portion is greater than the area threshold, the foreign object detection unit 339 determines that a foreign object is present. Additionally, the foreign object detection unit 339 compares the length of the block portion with a length threshold pre-stored in the inspection information storage unit 346b. Then, if the length of the block portion is greater than the length threshold, the foreign object detection unit 339 determines that a foreign object is present. In the case of a foreign object, the foreign object detection unit 339 stores foreign object location information (e.g., coordinate information indicating the location of the foreign object) used to determine the location of the foreign object in the inspection result storage unit 346d.

[0136] On the other hand, if the area of ​​the block portion is less than or equal to the area threshold and the length of the block portion is less than or equal to the length threshold, the foreign object detection unit 339 determines that there is no foreign object.

[0137] Furthermore, the foreign object detection unit 339 performs the same foreign object detection processing as described above, based not only on the hue image but also on the chroma image of the inspected area. Foreign object detection based on the chroma image utilizes the chroma difference relative to the resist region 4.

[0138] Specifically, the foreign object detection unit 339 first obtains a binarized chroma image, which is generated by binarizing each pixel of the chroma image using chroma components. In this embodiment, the binarized chroma image is obtained by comparing the chroma threshold pre-stored in the inspection information storage unit 346b with the chroma S of each pixel in the chroma image, and then binarizing each pixel in the chroma image. The resulting binarized chroma image becomes a black and white image having 0 (dark parts) and 1 (bright parts). The binarized chroma image is stored in the image storage unit 346a.

[0139] Additionally, for reference, a color image of a printed circuit board 1 with black hair X3 attached is shown (see reference). Figure 11 ) and a color image of a printed substrate 1 with white hair X4 attached (see reference) Figure 12As shown above, in the chroma image, the chroma values ​​of black hair X3 and white hair X4 are significantly different from the chroma value of resist region 4 for inspection. Therefore, in the binarized chroma image, for example, black hair X3 and white hair X4 are represented as dark areas, and resist region 4 is represented as a bright area.

[0140] After obtaining the binarized chroma image, the foreign object detection unit 339 sets the resist region 4 in the binarized chroma image, which is determined by the resist region information obtained by the resist region information acquisition unit 337, as the inspection object (inspection range).

[0141] Based on this, the foreign object detection unit 339 performs a process to determine the connecting components of pixels (e.g., dark parts) in the inspected object (inspection range) that have a chroma different from that of the resist region 4 (e.g., bright parts), and calculates the area and length of the determined connecting components (block parts).

[0142] Then, the foreign object detection unit 339 compares the area of ​​the block portion with the area threshold, and the length of the block portion with the threshold. If the area of ​​the block portion is greater than the area threshold, or the length of the block portion is greater than the length threshold, the foreign object detection unit 339 determines that a foreign object is present. The location information (coordinate information, etc.) of the detected foreign object is stored in the inspection result storage unit 346d.

[0143] Furthermore, the foreign object detection unit 339 can also determine the presence of a foreign object if the area of ​​the block portion is greater than the area threshold and the length of the block portion is greater than the length threshold. Alternatively, parameters other than area and length (such as thickness, shape, etc.) can be used to determine the presence of a foreign object.

[0144] On the other hand, if the area of ​​the block portion is less than or equal to the area threshold and the length of the block portion is less than or equal to the length threshold, the foreign object detection unit 339 determines that there is no foreign object.

[0145] Then, the foreign object detection unit 339 performs foreign object detection processing based on hue images or chroma images on all inspected areas of the printed circuit board 1. That is, the foreign object detection unit 339 performs the aforementioned foreign object detection processing using all hue images or chroma images of the printed circuit board 1 to be inspected. The detection results of foreign objects in all inspected areas are stored in the inspection result storage unit 346d. In this embodiment, the process of foreign object detection by the foreign object detection unit 339 is equivalent to a "foreign object detection process".

[0146] The good / bad determination unit 340 determines the quality of a foreign object based on its positional relationship with the component mounting area Ma, as detected by the foreign object detection unit 339. In this embodiment, if the foreign object detected by the foreign object detection unit 339 overlaps with or is in contact with the component mounting area Ma, the good / bad determination unit 340 determines the foreign object as "unqualified".

[0147] More specifically, the good / bad determination unit 340 determines, based on the foreign object location information and installation area information stored in the storage units 346c and 347d, whether at least one of the multiple coordinates determined by the foreign object location information in the inspected area is included within the range of coordinates determined by the installation area information. Furthermore, if at least one of the multiple coordinates of the foreign object is included within the coordinate range of the component installation area Ma, the good / bad determination unit 340 determines the foreign object as "unqualified".

[0148] For example, such as Figure 13 As shown, when foreign object X overlaps with component mounting area Ma, multiple coordinates of the foreign object are contained within the coordinate range of component mounting area Ma. Therefore, the defect determination unit 340 determines that the foreign object X is "unqualified". Additionally, for example, as... Figure 14 As shown, when the foreign object X is in contact with the component mounting area Ma, at least one of the multiple coordinates of the foreign object is included in the coordinate range of the component mounting area Ma, so the good / bad determination unit 340 determines the foreign object as "unqualified".

[0149] On the other hand, if none of the coordinates of the foreign object are included in the coordinate range of the component mounting area Ma, the good / bad determination unit 340 determines that the foreign object is "not a problem". The determination result of the good / bad determination unit 340 is stored in the inspection result storage unit 346d in a state associated with the foreign object location information.

[0150] Furthermore, the good / bad determination unit 340 takes all inspected areas of the printed circuit board 1 as objects and performs the inspection process related to the good / badness of foreign objects. If the foreign object detection unit 339 does not detect any foreign objects in any of the inspected areas of the printed circuit board 1, or if a foreign object is detected but is determined to be "no problem," the good / bad determination unit 340 determines that the printed circuit board 1 under inspection is without abnormality.

[0151] On the other hand, if the foreign object detection unit 339 detects a foreign object and there is an inspected area that is determined to be "unqualified" for that foreign object, the good / bad determination unit 340 will also determine that the printed circuit board 1 to be inspected is unqualified. The determination result of the good / bad determination unit 340 is stored in the inspection result storage unit 346d. In addition, the determination result is reported to the outside via the display unit 345, the communication unit 347, etc. In this embodiment, the process of determining the good or bad of a foreign object by the good / bad determination unit 340 is equivalent to a "good / bad determination process".

[0152] When the display control unit 341 causes the display unit 345 to display information stored in the storage unit 346, it controls the content of the display. In this embodiment, the display control unit 341 can use the information stored in the storage unit 346 to display on the display unit 345 an image (hue image, chroma image, or color image) of the inspected area where the foreign object is detected by the foreign object detection unit 339, overlaid with an image corresponding to the component mounting area Ma (e.g., an image of a frame representing the outer edge of the component mounting area Ma). Figure 13 , Figure 14 Such an image). That is, the display control unit 341 can display an image on the display unit 345 showing the positional relationship between the foreign object detected by the foreign object detection unit 339 and the component mounting area Ma.

[0153] Furthermore, the display control unit 341 can display, on the display unit 345, foreign objects detected by the foreign object detection unit 339 that are determined to be "unqualified" by the good / bad judgment unit 340 and foreign objects that are not determined to be "unqualified" by the good / bad judgment unit 340, in a distinguishable manner. In this embodiment, for example, as... Figure 15 As shown, information indicating "unqualified" (e.g., the word "B") is displayed for foreign objects X that are determined to be "unqualified" by the good / bad determination unit 340. On the other hand, information indicating that they are not "unqualified" (e.g., the word "NB") is displayed for foreign objects X that are not determined to be "unqualified" by the good / bad determination unit 340.

[0154] As described in detail above, according to this embodiment, even if a foreign object X is detected, if it is determined that the foreign object X will not cause functional problems to the printed circuit board 1 based on its positional relationship with the component mounting area Ma, the foreign object can be exempted from being deemed unqualified. Therefore, it is possible to more reliably prevent the determination of unqualified printed circuit board 1 due to foreign objects that are not considered to cause functional problems to the printed circuit board 1. As a result, the number of printed circuit boards 1 that are rejected due to being unqualified can be reduced, and the yield rate can be improved.

[0155] On the other hand, if it is believed that a detected foreign object, based on its positional relationship with the component mounting area Ma, could cause a functional problem with the printed circuit board 1, then the foreign object can be determined as non-conforming. Therefore, by properly detecting foreign objects that could cause functional problems with the printed circuit board 1, it is possible to more reliably prevent the printed circuit board 1 from being mistakenly determined as a conforming product.

[0156] Furthermore, in this embodiment, if a foreign object overlaps or is in contact with the component mounting area Ma, the foreign object is determined to be defective. Therefore, it is relatively easy to determine whether a foreign object is defective and could cause functional problems with the printed circuit board 1. As a result, the burden of the determination process can be reduced.

[0157] Furthermore, the display unit 345 can display at least an image showing the positional relationship between the foreign object detected by the foreign object detection unit 339 and the component mounting area Ma. Therefore, the positional relationship between the detected foreign object and the component mounting area Ma can be easily grasped visually. This improves convenience related to confirming whether the inspection was appropriate (according to the target), and confirming / adjusting inspection conditions.

[0158] Furthermore, hair such as brown or blonde hair is configured to detect foreign objects by utilizing the hue difference between the hair and the green resist region 4, at least within the resist region 4 of the hue image, using the hue difference with the resist region. Therefore, brown or blonde hair located in the resist region 4 can be detected with high precision, improving the detection capability of foreign objects.

[0159] Furthermore, hairs such as black and white hairs in foreign objects are particularly prone to chroma differences relative to the green resist region 4. This allows for the detection of foreign objects by utilizing the chroma difference relative to the resist region 4. Therefore, black and white hairs located in the resist region 4 can be detected with high precision, further improving the detection capability of foreign objects.

[0160] Furthermore, the implementation is not limited to the description of the above embodiments; for example, it can also be implemented as follows. Of course, other application examples and modifications not illustrated below are also possible.

[0161] (a) In the above embodiment, the good / bad determination unit 340 is configured to determine the good / bad nature of the foreign object based on whether at least one of a plurality of coordinates determined by the foreign object location information is included in the coordinate range determined by the installation area information. In contrast, as... Figure 16 As shown, the good / bad determination unit 340 can also calculate the area PP from the foreign object X to the area where a component may be installed. Figure 12The distances between objects within the component mounting area, including the area indicated by the medium-thick double-dotted line, pad 3b, and solder paste 5, are used to determine the quality of foreign object X based on whether the minimum value of these distances exceeds a pre-defined judgment value Dk. Figure 16 In the example shown, distances D1, D2, D3, D4, and D5 are calculated, and the quality of the foreign object X is determined by comparing the minimum distance D3 (which is the minimum of these distances D1 to D5) with the judgment value Dk.

[0162] Furthermore, according to the above-described good / bad determination method, the result is that the distance between the foreign object X and the component mounting area Ma (refer to the outer edge of the determination value Dk, which is the distance from the outer edge of the area PP, pad 3b, and solder paste 5) is taken as the outer edge of the determination value Dk. Figure 17 Determining whether they overlap or are adjacent.

[0163] (b) In the above embodiment, the component mounting area Ma is rectangular, but the shape of the component mounting area Ma is not limited to this. For example, it can be appropriately changed according to the shape of the pad 3b, the component, etc.

[0164] (c) In the above embodiment, the foreign object is configured to determine whether it is good or bad by determining whether it overlaps with or is adjacent to the component mounting area Ma. However, the method for determining the quality of a foreign object is not limited to this; the determination of the quality of a foreign object can be based on the positional relationship of the foreign object relative to the component mounting area Ma. Therefore, for example, the quality of the foreign object can also be determined based on the shortest distance from the component mounting area Ma to the foreign object, the average distance from multiple locations of the foreign object to the component mounting area Ma, etc.

[0165] (d) In the above embodiment, the display control unit 341 can display foreign objects detected by the foreign object detection unit 339 on the display unit 345, but it can also selectively display only foreign objects that are determined to be unqualified by the good or bad determination unit 340.

[0166] Furthermore, when multiple foreign objects are present, the display control unit 341 can display information related to these foreign objects on the display unit 345 in order of their distance from the component mounting area Ma. For example, magnified images of each foreign object can be arranged and displayed on the display unit 345 in order of their distance from the component mounting area Ma.

[0167] Furthermore, the display control unit 341 can selectively display only foreign objects that are less than a predetermined distance away from the component mounting area Ma on the display unit 345. In this case, the component mounting area Ma can also be configured to be magnified / reduced, and the foreign object to be displayed can be changed by magnifying or reducing the component mounting area Ma.

[0168] (e) In the above embodiment, the resist area information acquisition unit 337 is configured to acquire resist area information by extracting a portion of a certain range of hue from the hue image of the printed circuit board 1 to be inspected as the resist area. Alternatively, the resist area information acquisition unit 337 can also acquire resist area information by extracting a portion of a certain range of chroma from the chroma image as the resist area. Of course, both methods for acquiring resist area information can be used.

[0169] (f) In the above embodiment, the resist area information acquisition unit 337 is configured to acquire resist area information based on the image of the printed circuit board 1 of the object to be inspected.

[0170] In contrast, the resist area information acquisition unit 337 can also acquire resist area information by at least one of obtaining a hue image of the main substrate using a main color image and extracting areas with the same hue as the resist area from the hue image, and obtaining a chroma image of the main substrate using a main color image and extracting areas with the same chroma as the resist area from the chroma image. The main color image is a color image of the main substrate (not shown) of the ideal printed circuit board 1. The main color image can be acquired, for example, by taking a picture with a camera 322 while the main substrate supplied by the solder printing post-inspection device 13 is illuminated by an illumination device 321.

[0171] By configuring the resist area information to be obtained based on the main color image, sufficiently accurate resist area information can be obtained based on the relationship with the printed circuit board 1 of the object being inspected, without using design information or manufacturing information.

[0172] Furthermore, by extracting regions with the same hue and chroma as the resist region from the hue and chroma images, resist region information can be obtained. Therefore, compared to using a brightness image, the resist region 4 in the main substrate can be determined more accurately. As a result, more accurate resist region information can be obtained.

[0173] Furthermore, the resist area information acquisition unit 337 can acquire resist area information based on at least one of the design information and manufacturing information of the printed circuit board 1. The design information can include CAD data of the printed circuit board, and the manufacturing information can include Gerber data of the printed circuit board.

[0174] By using design information and manufacturing information to obtain resist area information, even when the printed circuit board 1, main board, etc. are not available, sufficiently accurate resist area information can be easily obtained based on the relationship with the printed circuit board 1 of the object to be inspected.

[0175] (g) In the above embodiment, the foreign object detection unit 339 is configured to detect foreign objects using a hue image and a chroma image based on a color image obtained by the camera 322. However, it may also use only one of the hue image and the chroma image for foreign object detection. Alternatively, the foreign object detection unit 339 may use images other than hue and chroma images for foreign object detection. Therefore, it may also be configured to use a color image (RGB image) and a brightness image obtained based on the color image for foreign object detection. Furthermore, a brightness image refers to an image representing the brightness of each pixel in the color image.

[0176] (h) In the above embodiment, each ring lamp 321a, 321b, and 321c is configured to illuminate white light, but it can also illuminate red, blue, or green light (i.e., different colors). Alternatively, in this case, the camera 322 can be configured as a monochrome camera, and each time the light is sequentially illuminated from each ring lamp 321a, 321b, and 321c, the camera 322 captures images of the printed circuit board 1, obtaining a total of three images. Then, a hue image, a chroma image, etc., can be obtained based on these three images. Furthermore, each of the three images has a parameter value set for R (red), G (green), or B (blue) corresponding to each pixel. Therefore, these three images can be considered equivalent to "color images".

[0177] (i) In the above embodiments, when detecting foreign objects, the hue image and chroma image are binarized to obtain a binarized hue image and a binarized chroma image, but it is not necessarily necessary to obtain a binarized image. Therefore, for example, it may be configured to directly use the hue image or chroma image to detect foreign objects. For example, it may be configured to calculate the area, length, etc. of a portion of hue or chroma within a certain range in the hue image or chroma image, and detect foreign objects based on that area and length.

[0178] Symbol explanation:

[0179] 1...Printed substrate

[0180] 4…Resist Area

[0181] 5…Solder paste

[0182] 13…Post-solder printing inspection device (substrate inspection device)

[0183] 321…Lighting device (image acquisition unit)

[0184] 322… Camera (Image Acquisition Unit)

[0185] 335…Hue Image Acquisition Unit (Hue Image Acquisition Section)

[0186] 336…Saturation Image Acquisition Unit (Saturation Image Acquisition Section)

[0187] 337…Resist Area Information Acquisition Department (Resist Area Information Acquisition Unit)

[0188] 339…Foreign Object Detection Department (Foreign Object Detection Unit)

[0189] 340…Good / Bad Judgment Department (Good / Bad Judgment Unit)

[0190] 345… Display Section (Display Unit)

[0191] Ma… Component mounting area

Claims

1. A substrate inspection apparatus for inspecting a printed circuit board on which solder paste has been printed and on which components will be mounted in a subsequent process, the substrate inspection apparatus being characterized in that it comprises: The image acquisition unit is capable of acquiring an image of a defined inspected area in the printed circuit board that includes a component mounting area and is larger than the component mounting area, wherein the component mounting area is the area corresponding to the mounting position of the component relative to the printed circuit board; The foreign object detection unit detects foreign objects in the inspected area based on the image acquired by the image acquisition unit. as well as The good / bad determination unit determines the quality of the foreign object based on its positional relationship with the component mounting area detected by the foreign object detection unit. When a foreign object detected by the foreign object detection unit overlaps with or comes into contact with the component mounting area, If the area of ​​a block portion of a foreign object detected by the foreign object detection unit is greater than a predetermined area threshold, or if the length of a block portion of a foreign object detected by the foreign object detection unit is greater than a predetermined length threshold, the good / bad determination unit determines that the foreign object is unqualified. When the foreign object detected by the foreign object detection unit does not overlap with or contact the component mounting area. Even if the area of ​​the block portion of the foreign object detected by the foreign object detection unit is greater than the specified area threshold, or the length of the block portion of the foreign object detected by the foreign object detection unit is greater than the specified length threshold, the good or bad determination unit will not determine the foreign object as unqualified.

2. The substrate inspection apparatus as described in claim 1, characterized in that, It has a display unit capable of displaying information. The display unit is configured to at least display an image showing the positional relationship between the foreign object detected by the foreign object detection unit and the component mounting area.

3. The substrate inspection apparatus as described in claim 1, characterized in that, The printed circuit board has a green resist area. The image acquisition unit is configured to use multiple colored lights to acquire a color image of the inspected area. The substrate inspection device further includes: A resist area information acquisition unit acquires resist area information for determining the extent of the resist area in the printed circuit board; and The hue image acquisition unit uses the color image acquired by the image acquisition unit to obtain the hue image of the inspected area. The foreign object detection unit is configured to detect foreign objects in at least the resist region determined by the resist region information of the hue image by means of a hue difference relative to the resist region.

4. The substrate inspection apparatus as described in claim 2, characterized in that, The printed circuit board has a green resist area. The image acquisition unit is configured to use multiple colored lights to acquire a color image of the inspected area. The substrate inspection device further includes: A resist area information acquisition unit acquires resist area information for determining the extent of the resist area in the printed circuit board; and The hue image acquisition unit uses the color image acquired by the image acquisition unit to obtain the hue image of the inspected area. The foreign object detection unit is configured to detect foreign objects in at least the resist region determined by the resist region information of the hue image by means of a hue difference relative to the resist region.

5. The substrate inspection apparatus according to any one of claims 1 to 4, characterized in that, The printed circuit board has a green resist area. The image acquisition unit is configured to use multiple colored lights to acquire a color image of the inspected area. The substrate inspection device further includes: A resist area information acquisition unit acquires resist area information for determining the extent of the resist area in the printed circuit board; and The chroma image acquisition unit uses the color image acquired by the image acquisition unit to obtain the chroma image of the inspected region. The foreign object detection unit is configured to detect foreign objects by utilizing the chroma difference relative to the resist region in at least the resist region region of the chroma image determined by the resist region information.

6. A substrate inspection method for inspecting a printed circuit board on which solder paste has been printed and on which components will be mounted in subsequent processes, the method being characterized by comprising: The image acquisition process is capable of acquiring an image of a defined inspected area in the printed circuit board that includes a component mounting area and is larger than the component mounting area, wherein the component mounting area is the area corresponding to the mounting position of the component relative to the printed circuit board; The foreign object detection process detects foreign objects in the inspected area based on the image acquired by the image acquisition process. as well as The defect determination process assesses the quality of a foreign object based on its position relative to the component mounting area, as detected by the foreign object detection process. In the good / bad determination process, When a foreign object detected by the foreign object detection process overlaps with or is in contact with the component mounting area... If the area of ​​a block portion of a foreign object detected by the foreign object detection process is greater than a specified area threshold, or if the length of a block portion of a foreign object detected by the foreign object detection process is greater than a specified length threshold, the foreign object is deemed unqualified. When the foreign object detected by the foreign object detection process does not overlap with or contact the component mounting area. Even if the area of ​​the block portion of the foreign object detected by the foreign object detection process is greater than the specified area threshold, or the length of the block portion of the foreign object detected by the foreign object detection process is greater than the specified length threshold, the foreign object will not be deemed unqualified.

Images