JP2004053369A - Implemented component inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an implemented component inspection method for efficiently inspecting an inspected substrate based on an image. <P>SOLUTION: In a processing apparatus 5 of the implemented component inspection apparatus 1, a camera 3 picks up and obtains the image of the inspected substrate S, a region corresponding to an inspected region is extracted from the image of the inspected substrate S based on a mask image for indicating the inspected region and an inspected image is created. Missing components etc. of the implemented components can be inspected on the inspected substrate S by comparing the inspected image with a master image as an inspection reference. Before the inspection, the camera 3 picks up and obtains an image of a master substrate as the inspection reference. The master image as the inspection reference can be easily created by extracting the region corresponding to the inspected region from the image of the master substrate. The inspected substrate S can be efficiently inspected based on the image. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mounted component inspection method for imaging a substrate to be inspected on which mounted components such as a chip resistor and a chip capacitor are mounted, and inspecting the inspected substrate based on the image.
[0002]
[Prior art]
The following are known as this type of mounted component inspection method in the related art. That is, position data indicating the position where the mounted component is to be mounted on the board to be inspected, shape data indicating the shape of the mounted component, and the like are created in advance as the inspection information, and the inspection information and the image of the inspected board are captured. Based on the above, whether or not the mounted components are properly mounted on the board to be inspected is inspected (for example, see Japanese Patent Application Laid-Open No. 9-152317).
[0003]
[Problems to be solved by the invention]
However, in the mounting component inspection method as described above, it takes a lot of time to create inspection information such as position data and shape data of the mounting component. Further, when the type of the substrate to be inspected changes, it is necessary to create new inspection information each time, which is extremely complicated.
[0004]
Therefore, the present invention has been made in view of such circumstances, and an object of the present invention is to provide a mounted component inspection method capable of efficiently inspecting a substrate to be inspected based on an image.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a mounted component inspection method according to the present invention is a mounted component inspection method for inspecting a board to be inspected on which a mounted component is mounted, and a master mounted with a reference mounted component serving as an inspection standard. A step of capturing an image of the board, and an image of the master board, based on the captured image of the master board and a mask image indicating an area where the reference mounting component is mounted as an inspection area; A step of creating a master image in which an area corresponding to the inspection area is extracted; a step of imaging the board to be inspected to obtain the image; and a step of inspecting the board to be inspected based on the captured image and the mask image. It is characterized by comprising a step of creating an inspection image by extracting an area corresponding to an inspection area in an image obtained by capturing the substrate, and a step of comparing the master image and the inspection image.
[0006]
In this mounting component inspection method, an image of a substrate to be inspected is captured and an image thereof is acquired, and a region corresponding to the inspection region is extracted from the image of the substrate to be inspected based on a mask image indicating the inspection region. Create an image to be inspected. By comparing the image to be inspected created in this way with the master image which is the inspection reference, it is possible to inspect the mounted component on the inspected substrate for missing parts, misalignment and the like. Then, before performing this inspection, an image of the master substrate on which the reference mounting component serving as the inspection reference is mounted is obtained and an image thereof is acquired. Based on the mask image, the image of the master substrate corresponding to the inspection area corresponds to the image. By extracting an area to be inspected, a master image indicating data on a reference mounted component serving as an inspection reference can be created extremely easily. Further, by creating such a master image, even when the type of the board to be inspected is changed, the master board corresponding to the new board to be inspected is imaged, so that the reference mounting component serving as the inspection reference can be obtained. Data can be easily obtained. Therefore, according to the mounting component inspection method according to the present invention, it is possible to efficiently inspect the inspection target board based on the image.
[0007]
In the mounted component inspection method according to the present invention, the mask image is created by capturing an image of the unmounted board before mounting the reference mounted component and obtaining the image, and connecting the reference mounted component on the unmounted board. Imaging a solder substrate coated with solder for obtaining an image of the solder substrate, and taking a pixel-by-pixel difference in luminance value between the image of the unmounted substrate and the image of the solder substrate. It is preferable to be performed. As described above, when the image obtained by capturing the image of the unmounted board and the image obtained by capturing the solder substrate are obtained, and the difference between the luminance values of the two images is obtained for each pixel, an image indicating the area where the solder is applied is obtained. be able to. Since the area where the solder is applied is an area where the reference mounting component is mounted, creation of a mask image indicating the area as an inspection area can be achieved very easily. Further, by creating such a mask image, even when the type of the substrate to be inspected changes, a new inspection target can be obtained by imaging the unmounted substrate and the solder substrate corresponding to the new substrate to be inspected. A mask image corresponding to a substrate can be easily created.
[0008]
In the mounted component inspection method according to the present invention, the step of performing the comparison is preferably a step of performing a comparison between the master image and the image to be inspected based on pixels indicating electrodes provided on the mounted component. A pixel indicating an electrode provided on a mounted component can have a higher luminance value than a peripheral pixel such as an unmounted substrate due to illumination or the like at the time of imaging. Therefore, if the master image and the image to be inspected are compared based on the pixels indicating the electrodes, it is possible to obtain an inspection result with high accuracy, such as a missing part or a position shift of the mounted component on the inspected substrate.
[0009]
Further, the step of performing the comparison is preferably a step of comparing the master image and the image to be inspected based on the integrated area of the pixels indicating the electrodes in the region corresponding to the inspection region. This makes it possible to easily inspect the mounted components on the inspected substrate for missing parts, positional deviations, and the like.
[0010]
Furthermore, when there are a plurality of inspection areas, the step of performing the comparison is preferably a step of comparing the master image and the image to be inspected for each area corresponding to the inspection area. This makes it possible to inspect the mounted board for missing parts, misalignment, and the like for each mounted component, and to specify a mounted component that has failed to be mounted.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of a mounted component inspection apparatus in which a mounted component inspection method according to the present invention is performed will be described in detail with reference to the drawings.
[0012]
As shown in FIG. 1, the mounted component inspection apparatus 1 has a measurement stage 2 for mounting a substrate S to be inspected on which mounted components such as a chip resistor and a chip capacitor are mounted. Is provided with a camera 3 for imaging the substrate S to be inspected. In the front part of the camera 3, there is provided a ring-shaped illumination 4 which is turned on during imaging and irradiates light to the substrate S to be inspected. The camera 3 is connected to a processing device 5 that captures a captured image. The processing device 5 performs various processes based on an image of the substrate S to be inspected and the like. It is determined whether or not the mounted component is properly mounted. A computer 6 as a user interface is connected to the processing device 5. The computer 6 has an input unit 7 such as a keyboard for outputting a signal input by an operator's operation to the computer 6, and a processing by the processing device 5. A display unit 8 for displaying a result or the like is connected.
[0013]
A mounted component inspection method performed by the mounted component inspection apparatus 1 configured as described above will be described. In the mounted component inspection apparatus 1, a mask image indicating an inspection region when inspecting the substrate to be inspected S and a master image as an inspection reference are created in advance, and then these images and the substrate to be inspected S are imaged. The inspection of the inspection target substrate S is performed based on the image.
[0014]
First, the mask image creation processing by the processing device 5 will be described with reference to the flowchart shown in FIG. First, the camera 3 captures an image A of the printed board (unmounted board) 11 before mounting a reference mounting component serving as an inspection reference (step S202). As shown in FIG. 3A, in the image A, a conductive pattern 12 provided on a printed board 11 is imaged. Subsequently, the camera 3 captures an image B of the solder-printed board (solder board) 13 on which the cream solder for connecting the reference mounting component is printed on the printed board 11 (step S204). As shown in FIG. 3B, in this image B, a cream solder 14 covering the conductive pattern 12 on the printed circuit board 11 is imaged. The reference mounted component means a mounted component mounted at an appropriate position, and serves as an inspection standard when inspecting whether or not the mounted component is properly mounted on the inspection target board S.
[0015]
After obtaining the image A and the image B, a difference image is created by taking the difference in luminance value between the two images for each pixel (step S206), and further, the difference image is binarized with a predetermined threshold to mask the image. The image C is created (Step S208). By this processing, as shown in FIG. 4, the area where the cream solder 14 is imaged in the image B appears as a white area in the mask image C (a black area is indicated by oblique lines). That is, since the white area in the mask image C is an area where the reference mounted component is mounted, the white area is used as an inspection area W _n (n = _n) for checking whether or not the mounted component is properly mounted. 1 to 6). Subsequently, subjected to region splitting into the mask image C, and the labeling and so the n-pad for each inspection area W _n to store a mask image C (Step S210).
[0016]
Thus, by obtaining an image B which the image A and the solder printed substrate 13 printed circuit board 11 is imaged is captured, it is made by very simple processing mask image C indicating the examination region W _n it can. Further, by creating such a mask image C, even when the type of the inspection target substrate S changes, the printed substrate 11 and the solder printed substrate 13 corresponding to the new inspection target substrate S can be imaged. Accordingly, a mask image C corresponding to a new inspection target substrate S can be easily created.
[0017]
Next, a process of creating a master image by the processing device 5 will be described with reference to the flowchart shown in FIG. First, the image of the master substrate M on which the reference mounting component serving as the inspection reference is mounted is captured by the camera 3 to obtain an image D (step S502). As shown in FIG. 6A, in the image D, three reference mounting parts 15 mounted across the cream solders 14 facing each other in the horizontal direction are imaged. Electrodes 17 are provided at both ends of each reference mounting component 15, and each electrode 17 is located on the cream solder 14.
[0018]
Subsequently, the above-described mask image C is read (step S504), and an AND operation based on a luminance value is performed for each pixel between the image D obtained by capturing the master substrate M and the mask image C, thereby obtaining the master image E. Is created (step S506). This process, as shown in FIG. 6 (b), the master image E, so that the region corresponding to the inspection area W _n of the mask image C is extracted from the image D (black region indicated by oblique lines) . Subsequently, the master image E is stored as an inspection reference when inspecting whether or not the mounted component is properly mounted (step S508).
[0019]
As described above, if the image D obtained by capturing the image of the master substrate M is obtained, the master image E indicating the data on the reference mounting component 15 serving as the inspection reference can be created by an extremely simple process. Further, by creating such a master image E, even when the type of the substrate to be inspected S changes, the master substrate M corresponding to the new substrate to be inspected S is imaged, and becomes an inspection reference. It is possible to easily acquire data on the reference mounted component 15.
[0020]
Next, the inspection processing of the inspection target substrate S by the processing apparatus 5 will be described with reference to the flowcharts shown in FIGS. First, as shown in FIG. 7, the substrate 3 to be inspected is imaged by the camera 3 and an image F thereof is obtained (step S702). As shown in FIG. 9A, in the middle and lower parts of the image F, two mounted parts 19 mounted across the cream solders 14 facing each other in the horizontal direction are imaged. Electrodes 21 are provided at both ends of each mounted component 19, and each electrode 21 is located on the cream solder 14. However, the lower mounted component 19 is slightly displaced in the horizontal direction. ing.
[0021]
Subsequently, the mask image C described above is read (step S704), and an AND operation based on a luminance value is performed for each pixel between the image F in which the substrate S to be inspected is captured and the mask image C, thereby performing the inspection. An image G is created (step S706). This process, as shown in FIG. 9 (b), the inspection image G, so that the region corresponding to the inspection area W _n of the mask image C is extracted from the image F (black area indicated by hatching ).
[0022]
After the inspection image G is created, a difference image is created between the master image E and the inspection image G by taking the difference in luminance value between pixels (step S708). An image H is created by converting the value into a value (step S710). By this processing, as shown in FIG. 10A, in the image H, an area having a large difference in luminance value between the master image E and the image to be inspected G appears as a white area (black area). The area is indicated by diagonal lines). In other words, the area indicating the upper electrode 17 in the master image E and the area corresponding to the positional deviation between the lower electrode 17 in the master image E and the lower electrode 21 in the inspection image G appear as white areas. As described above, the area indicating the electrodes 17 and 21 appears when the mounting part 19 is missing or misaligned, because the pixels indicating the electrodes 17 and 21 are attached to the pixels indicating the electrodes 17 and 21 by the illumination at the time of imaging. This is because a higher luminance value can be provided as compared with surrounding pixels such as.
[0023]
When binarized image H is generated as described above, into the step of determining whether the mounted component 19 for each inspection area W _n are properly implemented. That is, as shown in FIG. 8, the initial setting is “n = 0” (step S802), and then “n + 1 → n” is substituted (step S804). Then, it calculates the area Kb of the white region in the examination region _{W n} of the n-pad (step S806). The calculated area Kb compares whether it was specified value Ka or the set based on the area of the white region in the examination region W _n of the master image E (step S808). As a result of the comparison, when the calculated area Kb has reached the specified value or more Ka (Kb ≧ Ka), as this is defective, the defective (NG) marked for inspection region W _n of the n-pad moves to the next Write (step S810). On the other hand, when the calculated area Kb is not equal to or larger than the specified value Ka (Kb <Ka), the area is determined to be good and the process jumps to step S812. Subsequent to step S810 or when jumping from step S808, it is determined whether all the inspections have been completed, that is, whether the number of inspections has reached the number of all pads, that is, in this case, "n = 6?" (Step S812).
[0024]
Here, when “n = 6” has not been reached, it is determined that the inspection for all the pads has not been completed, and the process returns to step S804 again to start the processing for the inspection area W _{n + 1} of the (n + 1) th pad. On the other hand, when it has reached “n = 6”, it is determined that the inspection has been completed for all pads, and an inspection result image J is displayed on the display unit 8 to indicate the inspection result (step S814). As shown in FIG. 10B, the inspection result image J is obtained by adding an “X” mark as an NG mark to an image F obtained by imaging the substrate S to be inspected. In the substrate S to be inspected, regions corresponding to the inspection regions W ₁ and W ₂ are marked with “x” because the upper mounted component 19 is missing. In addition, although the position of the lower mounted component 19 is displaced, the area of the white region is smaller than the specified value (step S806), so it is determined that there is substantially no problem, and the inspection regions W ₅ and W _{5 The} area corresponding to No. ₆ is not marked with “x”.
[0025]
As described above, in the mounted component inspection device 1, and acquires the image F by imaging the inspected substrate S, based on the mask image C indicating the examination region W _n, an image to be inspected substrate S is captured It extracts an area corresponding to the inspection area W _n from F to create an inspection image G. By comparing the inspection image G created in this way with the master image E which is the inspection reference, the mounting component 19 on the inspection substrate S is inspected for missing parts, misalignment and the like. Thus, for inspecting focuses on examination region W _n, it is possible to speed up the calculation in the processing unit 5. Moreover, despite the mounting components 19 are properly implemented, some differences in the region other than the inspection area W _n (e.g., production lot or the like which is printed on the IC) to be inspected substrate S mounting failure cause the Can be prevented, and the inspection accuracy can be improved.
[0026]
Further, in the mounted component inspection apparatus 1, since the master image E and the inspection image G are compared based on the integrated area of the pixels indicating the electrodes 17 and 21 having a higher luminance value than the surrounding pixels, It is possible to easily and accurately obtain an inspection result of the mounted component 19 on the inspected substrate S, such as a missing part or a displacement. Furthermore, in order to perform a master image E for each region corresponding to the inspection area W _n compared with the inspection image G, it is possible to inspect the shortage and displacement or the like in the inspected substrate S for each mounted component 19, It becomes possible to specify the mounted component 19 that has become defective in mounting.
[0027]
As described above, the preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments. For example, when comparing the master image E and the image G to be inspected, a difference image is created by taking the difference between the luminance values of the two images for each pixel, and the difference image is binarized with a predetermined threshold to create an image H. (Steps S708 and S710), the image H may be created by extracting the overlap of the white regions (that is, the regions indicating the electrodes 17 and 21) of both images. When the image H is created in this manner, an NG mark may be written when the area of the extracted white region is equal to or smaller than a predetermined specified value. Further, the comparison between the master image E and the image G to be inspected may not be based on the area of the white region, but may be based on, for example, a relative difference in the position of the white region between the two images.
[0028]
【The invention's effect】
As described above, the mounted component inspection method according to the present invention is a mounted component inspection method for inspecting a board to be inspected on which mounted components are mounted, and a master board on which a reference mounted component serving as an inspection standard is mounted. A step of imaging and acquiring the image, and an inspection area in the image of the master substrate, based on the image of the master substrate and a mask image indicating an area where the reference mounting component is mounted as an inspection area. A step of creating a master image in which an area corresponding to is extracted, a step of imaging the substrate to be inspected and obtaining the image, and a step of imaging the substrate to be inspected based on the image and the mask image of the substrate to be inspected. By providing a step of creating an image to be inspected by extracting an area corresponding to the inspection area in the captured image, and a step of comparing the master image and the image to be inspected, it It is possible to efficiently perform inspection of the test substrate.
[Brief description of the drawings]
FIG. 1 is a schematic view showing one embodiment of a mounted component inspection apparatus in which a mounted component inspection method according to the present invention is performed.
FIG. 2 is a flowchart showing a mask image creation process by the processing device of the mounted component inspection device shown in FIG. 1;
3A and 3B are schematic diagrams illustrating a processed image in the processing device of the mounted component inspection apparatus illustrated in FIG. 1, wherein FIG. 3A is an image of a printed circuit board, and FIG. 3B is an image of a solder printed board; Image.
FIG. 4 is a schematic diagram showing a mask image created by a processing device of the mounted component inspection device shown in FIG. 1;
FIG. 5 is a flowchart showing a master image creation process by the processing device of the mounted component inspection apparatus shown in FIG. 1;
FIGS. 6A and 6B are schematic views showing a processed image in the processing device of the mounted component inspection apparatus shown in FIG. 1, wherein FIG. 6A is an image of a master board taken, and FIG. 6B is a master image.
7 is a flowchart showing the first half of the inspection processing of the substrate to be inspected by the processing device of the mounted component inspection apparatus shown in FIG. 1;
8 is a flowchart showing the latter half of the inspection processing of the substrate to be inspected by the processing device of the mounted component inspection apparatus shown in FIG. 1;
FIGS. 9A and 9B are schematic views showing a processed image in the processing device of the mounted component inspection apparatus shown in FIG. 1, wherein FIG. 9A is an image of a substrate to be inspected, and FIG. 9B is an image to be inspected.
10A and 10B are schematic diagrams showing a processed image in the processing device of the mounted component inspection apparatus shown in FIG. 1, wherein FIG. 10A is an image obtained by binarizing a difference image between a master image and an image to be inspected, and FIG. ) Is an inspection result image.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 mounting component inspection device, 3 camera, 4 ring illumination, 5 processing device, 11 printed board (unmounted board), 13 solder printed board (solder board), 14 cream solder, 15 Reference mounting parts, 17, 21 ... electrodes, 19 ... mounting parts, A ... image of printed board, B ... image of solder printed board, C ... mask image, D ... master board Image, E: master image, F: image of the inspected substrate, G: inspected image, H: binarized image, J: inspection result image, Ka: defined value, Kb: calculated area, M: master substrate, S: substrate to be inspected, W _n (n = 1 to 6): inspection area.

Claims (5)

A mounting component inspection method for inspecting a board to be inspected on which a mounting component is mounted,
A step of capturing an image of a master substrate on which a reference mounting component serving as an inspection reference is mounted, and
An area corresponding to the inspection area in the image of the master substrate is extracted based on an image of the master substrate and a mask image indicating an area where the reference mounting component is mounted as an inspection area. Creating a master image;
A step of imaging the substrate to be inspected and obtaining an image thereof,
Based on the image of the substrate to be inspected and the mask image, based on the image of the substrate to be inspected, to create an image to be inspected by extracting a region corresponding to the inspection region,
Performing a comparison between the master image and the image to be inspected. Creation of the mask image,
A step of capturing an image of an unmounted board before mounting the reference mounted component and acquiring the image,
A step of capturing an image of a solder substrate coated with solder for connecting the reference mounted component on the unmounted substrate and obtaining an image thereof,
2. The mounted component inspection according to claim 1, further comprising: a step of taking, for each pixel, a difference in luminance value between the image of the unmounted board and the image of the solder board. Method. The method according to claim 1, wherein the comparing is a step of comparing the master image and the image to be inspected based on a pixel indicating an electrode provided on the mounted component. Mounting component inspection method. The method according to claim 3, wherein the comparing is a step of comparing the master image and the image to be inspected based on an integrated area of a pixel indicating the electrode in a region corresponding to the inspection region. The mounting component inspection method described in 1. The step of performing the comparison is a step of comparing the master image and the image to be inspected for each area corresponding to the inspection area when a plurality of the inspection areas exist. The mounting component inspection method according to any one of claims 1 to 4.

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