JP4970852B2 - Visual inspection device - Google Patents

Description

  The present invention relates to a visual inspection apparatus that visually inspects an inspection object such as a printed circuit board, and more particularly to a visual inspection apparatus that enables an inspection object inspected by an automatic inspection apparatus to be efficiently visually inspected. is there.

  In general, a printed circuit board is inspected for its formation by an automatic inspection device, and a visual inspection is performed for those that may have a defective portion.

  As a system for performing such automatic inspection and visual inspection, for example, there is a system described in Patent Document 1 below.

  The visual inspection system disclosed in Patent Document 1 will be described in detail. This system includes an automatic inspection device and a visual inspection device. The automatic inspection device includes a light emitting unit that emits light to a printed circuit board. A light receiving unit that receives the reflected light, and a determination unit that determines the quality of the inspection object from the received image. This determination unit determines pass / fail by comparing the formation state of pads, patterns, silk, resist, and the like with reference data stored in advance in the storage unit. The printed circuit board determined as “defective” by the determination unit is then visually inspected. The visual inspection device includes a reading unit that reads an image stored in a hard disk or the like of an automatic inspection device, and a display unit that displays an image of a portion determined to be defective on a display of a personal computer or the like. The visual judgment can be performed based on the image displayed on the display unit.

According to such an appearance inspection system, since the inspection can be automatically performed by the primary inspection, the inspection time can be shortened and labor costs can be saved, and the visual inspection cannot be judged by the machine. Detailed inspection can be performed.
JP 2003-194733 A

  However, when the visual inspection is performed as described above, the following problems occur. In other words, the conventional visual inspection apparatus reads out and displays an image of a defective portion stored in a hard disk or the like. Therefore, if the photographed image is not clear, it is accurate even if a visual inspection is performed. Can't expect a good inspection.

  For this reason, in recent years, a printed circuit board that has been determined to be defective is set on the stage again so that an image of the defective portion can be taken with another camera. If the image is taken again, it takes time to set the printed circuit board on the stage or to move the camera to a defective part and take an image, and there is a problem that many printed circuit boards cannot be visually inspected in a short time. .

  Therefore, the present invention has been made paying attention to the above problems, and even when visual inspection is performed, a visual inspection apparatus that can perform inspection in a short time and can be accurately inspected visually. It is intended to provide.

That is, in order to solve the above-described problem, the present invention automatically inspects an inspection object based on an image acquired by the first camera, and images of defective portions and positions of the defective portions of the inspected inspection object. Is stored in the storage unit, the inspection object determined to be defective by the automatic inspection apparatus is accumulated in the stacker, the inspection object is picked up by using the pickup mechanism, and the inspection object is transported. A visual inspection device is provided for acquiring an image with two cameras and displaying the acquired image on a display for visual inspection . The image acquired by the first camera of the automatic inspection device is displayed on the display. A first display area; a second display area for displaying an image acquired by the second camera; a third display area for displaying an image of a reference inspection object; A fourth display area for displaying a list of remembered positions of defective places is provided, and when a position of a defective place in the fourth display area is selected, an image of the defective place is stored in the storage unit. The image stored in is read out and displayed in the first display area, the reference image of the same area as the defective portion is displayed in the third display area, and the image of the first display area is visually inspected for pass / fail If it is not possible to pick up, the inspection object collected in the visual inspection device is picked up and conveyed by accepting a predetermined input, and an image of the position at the defective portion is taken by the second camera and Redisplaying the information of the determination result stored in the storage unit based on the result of the visual inspection based on the image displayed on the second display area and displayed on the second display area; When a visual inspection for pass / fail can be performed with the image of the display area, the first display can be performed without picking up the inspection object from the stacker and photographing with the second camera by receiving a predetermined input. The information of the determination result stored in the storage unit is rewritten based on the result of the visual inspection based on the image displayed in the area.

  In this way, when the image photographed by the automatic inspection apparatus is clear, it is possible to make a visual judgment based on the image, while when the image photographed by the automatic inspection apparatus is unclear, Since a second camera provided separately can be re-photographed and visually inspected, the time required for re-inspection can be significantly reduced compared to re-photographing all defective printed circuit boards. become.

  According to the present invention, when the image photographed by the automatic inspection apparatus is clear, it is possible to make a visual judgment based on the image, while when the image photographed by the automatic inspection apparatus is unclear, Since a second camera provided separately can be re-photographed and visually inspected, the time required for re-inspection can be significantly reduced compared to re-photographing all defective printed circuit boards. become.

  Hereinafter, the visual inspection apparatus 3 according to the embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a schematic configuration diagram of an appearance inspection system 1 according to the present embodiment.

  The appearance inspection system 1 includes an automatic inspection apparatus 2 for automatically inspecting an inspection object and a visual inspection apparatus 3 for inspecting the inspection object by visual inspection. FIG. 2 is a functional configuration diagram of the automatic inspection device 2 and the visual inspection device 3 in the appearance inspection system 1. Hereinafter, details of the appearance inspection system 1 will be described.

  The automatic inspection apparatus 2 constituting the appearance inspection system 1 is configured to automatically inspect the formation state of pads, wiring patterns, resists, silk, and the like formed on the surface of the printed circuit board 4. A light emitting unit 24 that irradiates light, a camera 25 that acquires an image of the printed circuit board 4 by the light emitted from the light emitting unit 24, a pad, a wiring pattern, and the like from the image of the printed circuit board 4 photographed by the camera 25 And a determination unit 27 that inspects the formation state of the.

  The outline of the automatic inspection apparatus 2 will be described. First, when inspecting the printed circuit board 4, the printed circuit boards 4 to be inspected are accumulated in the stacker 21a, and the printed circuit boards 4 are picked up one by one from the top. 22 is picked up and placed on the stage 23. The printed circuit board 4 is placed on the stage 23 in a positioned state. As a positioning method, for example, as shown in FIG. 3, two side walls 230 that are orthogonal to each other are provided at the corner portion of the stage 23, and printing is performed with the claws 231 standing from below the stage 23. The printed board 4 is positioned at the corner by pressing the board 4. Then, the stage 23 on which the printed circuit board 4 is placed in this way is moved in the horizontal direction, and passes under the light emitting unit 24 and the camera 25 along the way, and an image of the printed circuit board 4 is taken at this time. The photographed image is separated into luminance areas such as pads, wiring patterns, resists, and silks by the image processing unit, and the quality of formation of pads, wiring patterns, resists, silks, and the like is determined for each of these images. When it is determined that a defective portion exists in the pad or the wiring pattern, the image of the defective portion and the position where the defective portion exists are stored in the storage unit 26. The printed circuit board 4 that has been determined to have a defective portion at the stage where all areas have been inspected is accumulated in the defective product stacking unit 21b, while it is determined that there are no defective portions. The printed circuit board 4 is accumulated in a non-defective product accumulation unit (not shown).

  For example, the determination unit 27 generates a histogram composed of the luminance and the number of pixels for each minute block separated for each certain luminance region, and the constant is stored in the storage unit 26 in advance in the minute block. It is determined how much the luminance width matches the number of pixels. If it is determined by this determination that it is defective, an identification number is assigned to the printed circuit board 4, and the position of the defective portion and an image including the defective portion are stored in the storage unit 26. . FIG. 4 shows an outline of the defective portion data stored in the storage unit 26. In FIG. 4, the “identification number” is the serial number of the printed circuit board 4 that is determined to have a defective portion, and matches the number of the printed circuit board 4 that is sequentially integrated from the bottom in the defective product stacking unit 21 b. It is. Further, the “coordinate position” of the defective portion indicates the position of the (X, Y) coordinates when the corner portion of the printed circuit board 4 placed on the stage 23 is used as the origin, for example. The “distance d” indicates the number of pixels from the center position to the outermost side when there are a plurality of defective portions adjacent to each other, and is used when marking M is performed by visual inspection later. Is. The “defective part image” is an image taken by the camera 25 of the automatic inspection apparatus 2. This image may be an image as it is captured by the camera 25 or may be an image separated for each predetermined luminance width by image processing. Further, not only one of these images, but also both the image as it is photographed and the image for each predetermined luminance width are stored in the storage unit 26, and each of the images is stored when visually inspecting later. You may make it judge by the switching and the quality of a defect location. If both images are stored in this way, even if the image cannot be visually judged from the image after the image processing, the visual judgment can be made from the captured image, When the image after the image processing is displayed, the pixels having unnecessary luminance can be erased and inspected at the time of visual judgment.

  Next, the configuration of the visual inspection apparatus 3 will be described. The visual inspection device 3 is configured to visually inspect the printed circuit board 4 inspected by the automatic inspection device 2, and includes an interface unit 30 for reading information stored in the storage unit 26 of the automatic inspection device 2, A second camera 32 that captures a surface image of the printed circuit board 4, a display 34 that displays an image captured by the second camera 32, and an input such as a result of visual judgment based on the image displayed on the display 34. And an input unit 35 for receiving.

  Of these, the interface unit 30 reads information stored in the storage unit 26 of the automatic inspection apparatus 2 online or offline, and in the case of online, for example, a dedicated communication cable between adjacent devices, Read information via a network such as the Internet. When reading information through a network such as the Internet, unattended automatic inspection and manned automatic inspection can be provided at geographically separated positions, and the respective processes can be performed. On the other hand, in the case of offline, for example, data indicating a defective portion is stored in a storage medium such as a CD and is read.

  The visual inspection device 3 includes a stage 31 for placing the printed circuit board 4 determined to be defective by the automatic inspection device 2 and a moving mechanism for moving the stage 31 and the second camera 32. The visual inspection apparatus 3 may be provided with a stacker similarly to the automatic inspection apparatus 2, or the printed circuit board 4 may be manually placed on the stage 31. When the stacker is provided, it is necessary to stack the printed circuit boards 4 in the reverse order of stacking in the defective product stacking portion 21b of the automatic inspection apparatus 2, and when manually placing the stacker, An operator needs to place the printed circuit boards 4 one by one. On the other hand, when the stacker is provided, it is not necessary to manually place the printed circuit board 4 one by one. When the printed circuit board 4 is manually placed, it is not necessary to newly shoot with the second camera 32. There is an advantage that it is not necessary to pick up or carry the substrate 4. Whether or not to provide a stacker is appropriately determined based on the environment in which the inspection is performed. When the printed circuit board 4 is placed on the stage 31, the printed circuit board 4 is positioned at the corner using the claws 231, the side walls 230, and the like, as in the case of the automatic inspection apparatus 2.

  The printed circuit board 4 placed on the stage 31 in this way is moved to below the second camera 32, where an image of the surface is taken. At this time, the second camera 32 moves in a direction orthogonal to the stage 31, thereby moving the second camera 32 to the defective portion and taking an image of the defective portion. As the second camera 32, a camera having a higher resolution than that of the automatic inspection apparatus 2 is used, and a camera having a function capable of enlarging an image of a defective portion by zooming up is used.

  The display 34 displays an image taken by the automatic inspection apparatus 2 and an image taken by the second camera 32. Specifically, as shown in FIG. 5, the display 34 has a first display area 341 for displaying an image acquired by the automatic inspection apparatus 2 on the same screen, and a second display of the visual inspection apparatus 3. The image is displayed so as to have a second display area 342 for displaying an image photographed by the camera 32 and a third display area 343 for displaying an image at the same position on the printed circuit board 4 serving as a reference. Further, the display 34 is provided with a fourth display area 344 for displaying a list of defective portions determined to be defective by the automatic inspection apparatus 2. In the fourth display area 344, an identification number of the printed circuit board 4 determined to be defective by the automatic inspection apparatus 2 and a list of defective portions corresponding to the identification number are displayed side by side in the vertical direction. By accepting the selection with a key or the like, the image at the defective portion is displayed in the first display area 341.

  When these displays are performed, when an image is displayed in the first display area 341, a round marking M is applied to the defective portion selected in the list, thereby making it possible to easily identify the defective portion. When the marking M is applied, for example, a marking M having a predetermined radius is applied to a defective area smaller than a predetermined number of pixels, while a defective area larger than the predetermined number of pixels is stored in the storage unit. A marking M having a radius of a distance d is applied. The marking M is set so as to blink or disappear when a predetermined key is pressed, so that an image of a portion hidden by the marking M can be viewed. For the marking M, not only a circular mark but also, for example, the luminance and color of a portion determined to be defective can be changed.

  By the way, when the operator presses a predetermined key in a state where the image of the defective portion is displayed in the first display region 341, the image of the defective portion captured by the second camera 32 is displayed in the second display region. 342 is displayed. At this time, the visual inspection device 3 reads the coordinate position of the selected defective portion and moves the stage 31 to the read coordinate position or moves the second camera 32 to display the image of the defective portion. Take a picture. In this embodiment, the image taken by the second camera 32 is displayed as it is in the second display area 342. At this time, the marking M is placed at the same position displayed on the first display screen. You may make it give. In this case as well, the marking M may be blinked or erased so that the marking M does not interfere with the visual inspection.

  On the other hand, in the third display area 343, an image having the same coordinates on the reference printed circuit board 4 is displayed. This is to determine how much the image displayed in the first display area 341 differs from the normal state.

  When an image is displayed on the second display unit, the image may be shifted depending on the positioning state on the stage 31. For this reason, for example, the image is aligned by taking a correlation with the image displayed on the first display unit, and the image displayed on the second display unit is shifted and displayed. Good.

  The input unit 35 instructs photographing with the second camera 32 described above, and accepts a result of visual inspection based on the image displayed in the second display area 342. With respect to the result of this visual inspection, a determination result is assigned in advance to a function key of the keyboard. Set to be. When the F1 key is pressed, information such as a defective part stored in the visual inspection device 3 is deleted.

  Next, operation states of the automatic inspection and the visual inspection in the appearance inspection system 1 configured as described above will be described with reference to the flowchart of FIG.

  First, the automatic inspection apparatus 2 picks up the printed circuit board 4 from the stacker 21, places it on the stage 23, and moves the stage 23 to take an image of the printed circuit board 4 (step S1). Then, the photographed image is separated into pads, wiring patterns, resists, silks, and the like using a predetermined luminance threshold value, and a luminance histogram is generated by dividing into fine blocks for each inspection object. Then, the formation state in the minute block is determined by comparing with the number of pixels within the predetermined luminance width stored in the storage unit 26 (step S2). At this time, for example, if the number of pixels in the predetermined luminance range of the histogram divided into minute blocks is small, it is determined that the pad is missing, and if the number of pixels in the predetermined luminance range is large, It is determined that “the pad is swollen”. If it is determined by this determination that a defective portion exists, a serial number is assigned to the printed circuit board 4, and the coordinate position of the defective portion and the position of the defective portion are assigned to the serial number. Remember the image. If there are a plurality of defective portions adjacent to each other, the distance d from the center position to the coordinate position of the outermost defective portion is also stored (step S3). Thereafter, the same inspection is performed on other regions and other printed circuit boards 4, and the printed circuit boards 4 that may have defective portions are sequentially accumulated in the defective product accumulating unit 21b (step S4). ).

  Next, when visually determining the printed circuit board 4 determined to be defective, the visual inspection device 3 reads data relating to the defective portion stored in the storage unit 26 of the automatic inspection device 2 online or offline (step T1). It is stored in its own storage unit 33 (step T2). Then, information relating to the defective portion corresponding to the first serial number is read from the information stored in the storage unit 33 (step T3), and a list of defective portions is displayed as a list in the fourth display area 344 (step T4). When the operator selects one of the lists (step T5), the image of the selected defective portion is displayed in the first display area 341 and also in the third display area 343. An image of the same region as a reference is displayed (step T6) so that an input of visual judgment by the operator can be received. Here, if the operator can make a visual determination based on the image displayed in the first display area 341, the input of F1 (normal) or F2 (defective) is accepted (step T10), and stored thereby. The information of the determination result at the defective portion stored in the unit 33 is deleted (step T11). On the other hand, if the operator cannot make a visual judgment based on the image displayed in the first display area 341, the HOME key input is accepted (step T7), and the coordinate position at the defective location is read to read the stage 31 or The second camera 32 is moved (step T8). Then, the second camera 32 takes an image of the defective portion and displays it in the second display area 342 (step T9). Similarly, based on the image displayed in the second display area 342, an input of F1 (visual determination OK) or F2 (visual determination NG) is accepted (step T10), thereby being stored in the storage unit. The information on the determination result at the defective portion is rewritten (step T11).

  As described above, according to the above-described embodiment, when the image taken by the automatic inspection apparatus 2 is clear, it can be visually determined based on the image. When the captured image is unclear, the image is taken by the second camera 32 so that it can be visually inspected. Therefore, the time required for the reinspection is remarkably compared with the case where the images of all defective portions are retaken. Can be shortened.

  In addition, this invention is not limited to the said embodiment, It can implement in a various aspect.

  For example, in the above embodiment, the visual inspection apparatus 3 has been described by taking an apparatus having the stage 31, the second camera 32, the display 34, and the input unit 35 as an example. However, these functions are disassembled, for example, the stage 31 Alternatively, the second camera 32 may be installed adjacent to the automatic inspection apparatus 2 and the display 34 and the input unit 35 may be provided in a remote place. In such a case, the printed circuit board 4 determined to be defective by the automatic inspection apparatus 2 is transported to the visual inspection apparatus 3 by an operator present at the place, and placed on the stage 31 there. The stage 31 and the second camera 32 are moved by a visual inspector at a remote location, and an image of a defective portion is taken so that visual inspection can be performed. In this way, for example, a worker existing on the automatic inspection apparatus 2 side can perform a simple operation and a visual inspection expert at a remote location can perform a visual inspection. In this case, the visual inspection device 3 functions as a system connected to a remote place.

  In the above embodiment, the printed circuit board 4 is described as an example of the inspection object. However, the present invention is not limited to this, and can be applied to other inspection objects such as a liquid crystal substrate, a mounting substrate, and a printed material. .

Schematic of an appearance inspection apparatus in an embodiment of the present invention Functional block diagram in the same form The perspective view which shows the stage in the same form The figure which shows the data stored in the memory | storage part of the automatic inspection apparatus and visual inspection apparatus in the same form The figure which shows the example of a screen structure of the visual inspection apparatus in the form The flowchart which shows the operation state of the external appearance inspection apparatus in the form

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Appearance inspection system 2 ... Automatic inspection apparatus 3 ... Visual inspection apparatus 4 ... Printed circuit board 21 ... Stacker 22 ... Pickup mechanism 23 ... Stage 230 ... Side wall 24. ..Light emitting unit 25 ... Camera 26 ... Storage unit 27 ... Determining unit 30 ... Interface unit 31 ... Stage 32 ... Second camera 33 ... Storage unit 34 ... Display 35 ... input unit 341 ... first display area 342 ... second display area 343 ... third display area 344 ... fourth display area 345 ... list display area

Claims (1)

An automatic inspection device that automatically inspects an inspection object based on an image acquired by the first camera, and stores an image of a defective portion of the inspection object inspected and a position of the defective portion in a storage unit;
The inspection object determined to be defective by the automatic inspection apparatus is accumulated in the stacker, the inspection object is picked up using a pickup mechanism, the inspection object is conveyed, and an image is acquired by the second camera. Provided with a visual inspection device that visually inspects the displayed image on a display,
On the display,
A first display area for displaying an image acquired by the first camera of the automatic inspection device;
A second display area for displaying an image acquired by the second camera;
A third display area for displaying an image of a reference inspection object;
A fourth display area for displaying a list of positions of the stored defective locations;
To have,
When the position of the defective part of the fourth display area is selected, the image of the defective part is read out and displayed in the first display area and displayed in the third display area. Display a reference image of the same area as the defective part,
When visual inspection for pass / fail cannot be performed with the image of the first display area, by accepting a predetermined input, the inspection object accumulated in the visual inspection apparatus is picked up and transported, and in the defective portion An image of a position is taken by the second camera and displayed in the second display area, and a determination stored in the storage unit based on a result of visual inspection based on the image displayed in the second display area Rewrite the resulting information,
When visual inspection for pass / fail can be performed on the image of the first display area, by accepting a predetermined input, the inspection object is picked up from the stacker and is not photographed by the second camera. The information of the determination result stored in the storage unit is rewritten based on the result of the visual inspection based on the image displayed in the one display area.
An appearance inspection system characterized by that.

Images