JP4302234B2 - Mounting parts inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mounting component inspection apparatus that is mounted on a surface mounter and detects a component mounting failure by imaging a component mounted on a substrate such as a printed circuit board.
[0002]
[Prior art]
Conventionally, a head unit for picking up components is mounted on a head unit movable between a component supply unit and a printed circuit board positioned at a predetermined work position so as to be able to move up and down and rotate. 2. Description of the Related Art A surface mounter that sucks a component and mounts the component at a predetermined position on a substrate is generally known.
[0003]
In this type of surface mounter, for example, a component may not be mounted on the board due to a component suction error or a drop off from the head, or a positional shift may occur. By detecting such a component mounting failure, It is required to sort out defective substrates.
[0004]
Therefore, conventionally, a laser distance sensor is mounted on the head unit, and the substrate surface is irradiated with laser light to check the unevenness of the substrate surface, and the presence or absence of component mounting is checked based on the height information. (JP-A-7-249895). In an apparatus in which a substrate recognition camera is mounted on the head unit, a mounted component is imaged using this camera, and the mounted state of the component is checked based on the image.
[0005]
[Problems to be solved by the invention]
In the above-described conventional apparatus using a laser distance sensor, the presence or absence of a component can be detected, but a defect in the mounting direction cannot be detected, and it is necessary to accurately irradiate a detection position with a laser beam. There is a drawback that the sensor mounting accuracy is required.
[0006]
In contrast, an apparatus that captures a mounted component using a substrate recognition camera mounted on a head unit can detect not only the presence of a component but also a defect in the mounting direction of the component. Therefore, accuracy is not required for mounting a camera or the like. Therefore, it can be said that it is more advantageous than an apparatus using a laser distance sensor.
[0007]
However, in order to take an image of a mounted component in this type of apparatus, it is necessary to move the head unit so that the camera is positioned above the mounted component after mounting the component, which causes a problem in reducing the tact time. It was. In addition, since it is difficult to recognize the parts with high accuracy, it cannot be said that the detection accuracy of defective mounting is necessarily good, and an improvement in detection accuracy has been desired.
[0008]
The present invention has been made to solve the above-mentioned problems, and a first object is to provide a mounting component inspection apparatus that can contribute to a reduction in tact time, and a second object is to An object of the present invention is to provide a mounting component inspection apparatus capable of detecting a mounting failure of a component with higher accuracy.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is configured to adsorb a component by a component mounting head mounted on a movable head unit, and move the component onto a substrate by moving the head unit to raise and lower the head. A mounting component inspection apparatus for a surface mounter configured to mount a component on a board, wherein the head unit is directed to the component mounting position when the head is disposed above the component mounting position on the substrate. Mounted imaging means, control means for controlling the imaging means to image the component mounting position before and after component mounting, and means for separating the image of the component mounting position imaged by the imaging means into a plurality of different color components When, and a detection means based on the image of the imaged component mounting position by the imaging means for detecting a part of the poor mounting, the detecting means, the component from the image after the component mounting An image obtained by removing an image before wearing and acquiring a component image for each of the plurality of color components, and performing component mounting failure based on the component image obtained by taking a logical sum of the component images for each color component. a shall be detected (claim 1).
[0010]
According to this apparatus, when the head unit is moved onto the substrate to mount the component and the component adsorbed by the head is arranged above the component mounting position, the image of the component mounting position can be automatically taken by the imaging means. For this reason, after mounting the component, it is possible to detect the mounting defect by imaging the mounted component without moving the head unit. In addition, since an image obtained by removing the image before component mounting from the image after component mounting and detecting component mounting based on the component images for each of a plurality of different color components, the extracted component image Reliability is remarkably improved, and it is possible to detect a component mounting failure with high accuracy.
[0012]
Na us, detection means, said plurality of different as the component images of the color components R (red), G (green), B the component image obtained by taking the logical sum of the part image of each color component (blue) it can be configured to detect the components of poor mounting based (claim 2).
[0013]
When a plurality of heads are mounted on the head unit, an imaging unit may be provided corresponding to each head (claim 3 ).
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0015]
1 and 2 show the structure of a surface mounter on which a mounting component inspection apparatus according to the present invention is mounted. As shown in the figure, on a base 1 of a surface mounting machine (hereinafter, abbreviated as a mounting machine), a printed board carrying conveyor 2 is arranged, and the printed board 3 is carried on the conveyor 2 to a predetermined level. Is stopped at the mounting work position. A component supply unit 4 is disposed on the side of the conveyor 2. The component supply unit 4 includes a component supply feeder, for example, a multi-row tape feeder 4a.
[0016]
A head unit 5 for mounting components is provided above the base 1. The head unit 5 is movable over the component supply unit 4 and the component mounting unit on which the printed circuit board 3 is located. In this embodiment, the head unit 5 is in the X-axis direction (direction of the conveyor 2) and Y-axis direction (X on the horizontal plane). In a direction perpendicular to the axis).
[0017]
That is, a fixed rail 7 in the Y-axis direction and a ball screw shaft 8 that is rotationally driven by a Y-axis servomotor 9 are disposed on the base 1, and a head unit support member 11 is disposed on the fixed rail 7. And a nut portion 12 provided on the support member 11 is screwed onto the ball screw shaft 8. The support member 11 is provided with a guide member 13 in the X-axis direction and a ball screw shaft 14 driven by an X-axis servo motor 15, and the head unit 5 is movably held by the guide member 13. A nut portion (not shown) provided on the head unit 5 is screwed onto the ball screw shaft 14. The support member 11 is moved in the Y-axis direction by the operation of the Y-axis servo motor 9, and the head unit 5 is moved in the X-axis direction with respect to the support member 11 by the operation of the X-axis servo motor 15. ing.
[0018]
The head unit 5 is provided with a head 20 provided with a tip 20 for absorbing a chip component at the tip. Each head 20 can be moved up and down and rotated about the central axis of the nozzle with respect to the frame of the head unit 5, and is operated by a lift drive mechanism and a rotation drive mechanism (not shown).
[0019]
The head unit 5 is also equipped with a camera 21 and an illuminating device 22 that capture images of components mounted on the printed circuit board 3. The camera 21 is composed of a CCD area sensor, and is configured to separate a color image into three primary colors of R (red), G (green), and B (blue), convert it into data, and output the data to an image processing unit 32 of a controller described later. ing. The illumination device 22 is composed of a white LED, a combination of R, G, and B LEDs, a fluorescent lamp, or the like, and is configured to provide illumination for imaging by the camera 21.
[0020]
As shown in FIG. 2, the camera 21 and the illumination device 22 are arranged with the head 20 interposed therebetween, and the state in which the head unit 5 is set above the printed circuit board 3 at the time of component mounting, that is, the head 20 (adsorption component) is the printed circuit board 3. When the head unit 5 is set so as to be positioned above the predetermined component mounting position (see FIG. 5), the camera 21 and the illumination device 22 are inclined to the unit 5 so as to be directed to the component mounting position P, respectively. Installed in.
[0021]
The mounting machine configured as described above includes a controller that comprehensively controls the operation thereof, and the servo motors 9, 15 and the like are electrically connected to the controller. Then, the drive operation of each servo motor 9 and the like is controlled in accordance with a program stored in advance in the controller, so that a mounting operation as described later is performed.
[0022]
FIG. 3 shows a part of a control system included in the controller, which is responsible for detecting a component mounting failure in the mounting operation, that is, a part related to the component inspection apparatus of the present invention.
[0023]
The control system shown in this figure includes a main calculation unit 30, a camera control unit 31, an image processing unit 32, a storage unit 33, a display unit 34, and an input unit 35.
[0024]
The main arithmetic unit 30 comprehensively controls processing for component mounting failure detection, and outputs a control signal to the camera control unit 31 so as to image the mounted component by the camera 21 and an image processing unit 32. The component is recognized based on the image data output from, and a specific determination is made regarding a mounting failure.
[0025]
The camera control unit 31 is configured to control the operation of the camera 21 and the illumination device 22 based on a control signal from the main calculation unit 30.
[0026]
The image processing unit 32 extracts and extracts an image corresponding to the component from the image captured by the camera 21 by performing predetermined processing on the data of the R, G, and B color components output from the camera 21. The image data of the parts is configured to be output to the main calculation unit 30.
[0027]
The storage unit 33 stores information (referred to as component data) necessary for determining a component mounting failure. For example, information on the shape of the component and data such as an allowable value of mounting deviation are stored in the storage unit 33. Is remembered.
[0028]
The display unit 34 and the input unit 35 include a CRT display and a keyboard, respectively. The display unit 34 and the input unit 35 are configured to input component data, programs, and the like. It is configured to perform a display when an error occurs.
[0029]
Here, processing for component mounting failure detection performed by the control system shown in FIG. 3 will be described using the flowchart of FIG. 4 together with the mounting operation.
[0030]
When the mounting operation is started, first, the head unit 5 is moved to the component supply unit 4 and the components are adsorbed by the head 20. At this time, after the head unit 5 is set above the component supply unit 4, the head 20 moves up and down, so that the component is adsorbed by the nozzle 20 a and picked up.
[0031]
When the suction of the components is completed, the head unit 5 is moved onto the printed board as shown in FIG. 5 so that the component Cp is disposed above the predetermined component mounting position P, and the component mounting position P before the component mounting. Is captured by the camera 21 (steps S1 and S2). As a result, an image of a predetermined area of the printed circuit board 3 including the component mounting position P as shown in FIG. 7A is picked up, and image data of each color component of R, G, and B of this image is stored in the image processing unit 32. Is output.
[0032]
When the imaging of the component mounting position P is completed, the head 20 moves up and down to mount the component Cp at the component mounting position P, and after mounting the component, the camera 21 captures the image of the component mounting position P again (step). S3, S4). As a result, an image of the component mounting position P including the component Cp as shown in FIG. 7 is taken, and image data of each color component is output to the image processing unit 32.
[0033]
Next, the image processing unit 32 performs a process of obtaining a difference image obtained by removing the image before the component mounting from the image after the component mounting for each color component, that is, a process of extracting the component image (step S5).
[0034]
Specifically, each color component image before and after component mounting is A / D converted to convert each image into a multi-gradation image. Then, after subtracting the gradation of the corresponding pixel in the image before component mounting from the gradation of each pixel in the image after component mounting, the absolute value of the gradation of each pixel is taken. Thus the difference image for each color component UNA by 7, i.e., an image corresponding to the component Cp is extracted.
[0035]
Then, the difference image of each color component is converted into a binarized image based on a predetermined threshold, and the logical sum of the difference image of each color component, that is, the logical sum of the corresponding pixels in the difference image of each color component is taken ( Steps S6 and S7). As a result, a final image corresponding to the component Cp is obtained.
[0036]
When an image corresponding to the component Cp is extracted in this way (referred to as an extracted component image), the image data is output to the main calculation unit 30, where the feature amount such as the center position, aspect ratio or area of the extracted component image is detected. In addition, the deviation and inclination from the mounting position are detected, and the component data corresponding to the component is read from the storage unit 33, and the component data and the detection data are compared (steps S8 and S9).
[0037]
Then, it is determined whether or not the component data and the detection data are within a preset error (step S10). If it is determined that the component data and the detection data are within the error (step S11), for example, the next component Cp is determined. The head unit 5 is moved above the component supply unit 4 so as to mount the component, and this flowchart is completed. On the other hand, if it is determined that it is not within the error in step S10 (step S11), for example, the subsequent mounting operation with respect to the printed circuit board 3 is stopped and a message to that effect is displayed on the display unit 34, and this flowchart ends.
[0038]
According to the above mounting machine, when the head unit 5 is set above the printed circuit board 3 for component mounting, the camera 21 and the illumination device 22 are naturally attached to the head unit 5 so as to be directed to the component mounting position P as described above. It is done. Therefore, after mounting the component Cp, the mounted component Cp can be imaged without moving the head unit 5 at all. Therefore, compared with the conventional mounting machine that needs to image the component after moving the head unit 5 after mounting the component, it is possible to image the mounted component Cp more efficiently, thereby contributing to the reduction of the tact time. Can do.
[0039]
Further, when detecting the mounting failure of the component Cp, a difference image is obtained by capturing the component mounting position P before and after mounting the component and removing the image before mounting the component from the image after mounting the component, which is an image including the mounting component Cp. In other words, since the image corresponding to the component Cp is extracted, the component image is extracted as compared with the case where the image corresponding to the component is extracted from only the image after the component is mounted and the component is recognized. The reliability of the component image from which a large amount of information is extracted is high (high accuracy). Therefore, it is possible to detect a component mounting failure with higher accuracy than in a conventional mounting machine of this type that recognizes a component only from an image after component mounting.
[0040]
In particular, in the mounting machine described above, the difference image is obtained for a plurality of color components R, G, and B, and the final image of the component Cp is obtained by taking the logical sum of the difference images. There is a feature that the reliability of the component image is high. That is, when extracting a component image based on a single color component, for example, if the color tones of the pattern D and the component Cp are approximate, the pattern D and the component are removed by removing the pattern D image. There may be a case where the overlapping part of Cp is lost and the part image cannot be extracted accurately. On the other hand, if difference images are obtained for a plurality of color components and these logical sums are taken, even if the color tones of the pattern D and the component Cp are approximate, the difference images of the respective color components are completely the same. Therefore, even if a defect such as that described above occurs in any one of the color component images, the defect is complemented by the other color component image. Therefore, the final difference image hardly has the above-described defects, and an accurate component image can always be extracted. As a result, a mounting defect of the component Cp can be detected with high accuracy.
[0041]
By the way, the mounting machine described above is an example of a mounting machine on which the component inspection apparatus according to the present invention is mounted, and the specific configuration of the component inspection apparatus and the mounting machine on which the component inspection apparatus is mounted departs from the gist of the present invention. It is possible to change appropriately within the range not to be.
[0042]
For example, in the mounting machine described above, in order to extract a component image, the color image is separated into three primary colors of R (red), G (green), and B (blue), and the component image is extracted based on the images of these color components. However, the component image may be extracted based on an image of any one of these colors or one color component other than R, G, and B. However, when recognizing a component based on an image of one color component, the extraction accuracy of the component image may be inferior as compared with the case of extracting a component image based on a plurality of color components as described above. Therefore, in order to improve detection accuracy, it is desirable to extract a component image based on a plurality of color component images. In this case, the color components are not limited to the three primary colors of R, G, and B, and the specific types and numbers of colors depend on the specific form and color of the printed circuit board 3 and the components to be mounted on it. What is necessary is just to select suitably so that a component image can be extracted more accurately. As a CCD area sensor, a color image is generally divided into R, G, and B color components and converted into data and output. Therefore, if these color components are selected, a commercially available camera 21 is used. The apparatus can be configured at low cost using
[0043]
In the above mounting machine, one head 20 is mounted on the head unit 5, and a pair of cameras 21 and a lighting device 22 are provided correspondingly. For example, the head unit 5 includes a plurality of heads. In a mounting machine in which 20 is arranged in parallel, a camera 21 and a lighting device 22 may be mounted corresponding to each head 20. In this case, the lighting device 22 may be shared by the heads 20.
[0044]
Furthermore, in the above mounting machine, the component mounting position P of the printed circuit board 3 is imaged by the camera 21, but for example, by imaging the board recognition mark written on the printed circuit board 3 by the camera 21. The camera 21 may be shared as a substrate recognition camera.
[0045]
【The invention's effect】
As described above, according to the present invention, when the head unit is moved onto the substrate to mount the component, the imaging unit is mounted on the head unit so that the imaging unit is naturally directed to the component mounting position. After the mounting, the mounted component can be detected without moving the head unit at all. Therefore, it is possible to detect defective mounting more efficiently than the conventional apparatus that images the mounted component after moving the head unit after mounting the component, thereby contributing to shortening of the tact time.
[0046]
Also, by imaging the component mounting position in the longitudinal component mounting, and detects the part of poor mounting based from the component mounting previous image in the part image obtained by removing the image before component mounting, an image of the mounting component It is possible to extract well, and thereby it is possible to detect a component mounting failure with high accuracy. In particular, in this case, the component mounting position image is separated into a plurality of different color components, and component images are obtained for each color component image, and component mounting defects are detected based on the obtained logical sum. since, it extracted the part remarkably improved reliability of image can be detected with an extremely accuracy of parts mounting failure.
[0047]
Further, when a plurality of heads are mounted on the head unit, an imaging unit may be provided for each head, and in this way, in an apparatus for mounting components on the plurality of heads, It is possible to detect a component mounting failure well.
[Brief description of the drawings]
FIG. 1 is a plan view showing a surface mounter to which a mounting component inspection apparatus according to the present invention is applied.
FIG. 2 is a front view showing a surface mounter to which the mounted component inspection apparatus according to the present invention is applied.
FIG. 3 is a block diagram showing a portion corresponding to a mounted component inspection device in a control system of a surface mounter.
FIG. 4 is a flowchart illustrating a process (including a mounting operation) for detecting a component mounting failure.
FIG. 5 is a diagram for explaining an imaging operation (before component mounting) of a component mounting position by a camera.
FIG. 6 is a diagram illustrating an imaging operation of a component mounting position by a camera (after component mounting).
FIG. 7 is a schematic diagram illustrating a process for detecting a component mounting failure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 3 Printed circuit board 5 Head unit 20 Head 21 Camera 22 Illumination device 30 Main calculating part 31 Camera control part 32 Image processing part 33 Memory | storage part 34 Display part 35 Input part P Component mounting position Cp Component

Claims (3)

The component is picked up by the component mounting head mounted on the movable head unit, and the component is moved onto the substrate by the movement of the head unit, and the component is mounted on the substrate as the head moves up and down. A mounting component inspection device for a surface mounter,
Imaging means mounted on the head unit so as to be directed to the component mounting position when the head is disposed above the component mounting position on the board, and the imaging to image the component mounting position before and after mounting the component Control means for controlling the means, means for separating the image of the component mounting position imaged by the imaging means into a plurality of different color components, and mounting of the component based on the image of the component mounting position imaged by the imaging means Detecting means for detecting a defect, the detection means is an image obtained by removing an image before component mounting from an image after component mounting, and acquires a component image for each of the plurality of color components, mounting component inspection device which is characterized that you detect the components of poor mounting on the basis of the component image obtained by taking the logical sum of the part images of each of these color components. Said detecting means, R (red) as component images of the plurality of different color components, G (green), a logical sum of the component images of the color components of the B (blue) and on the basis of the component image obtained by Rukoto The mounted component inspection apparatus according to claim 1, wherein the mounted component inspection device is configured to detect a component mounting failure. The head unit plural heads is mounted on the mounting component inspection apparatus according to claim 1 or 2, characterized in that each imaging means corresponding to each head is al provided.

Images