JP2005051032A - Method for inspecting package component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inspecting a package component in which packaging state of a package component on a board to be inspected can be inspected accurately regardless of displacement of the board when imaging. <P>SOLUTION: In package component inspection equipment 1, displacement between the position of a through hole in a first image obtained by removing the image of a reference package component from the image of an inspection reference, i.e. a master board, and the position of a through hole in a second image obtained by removing the image of a package component from the image of a board to be inspected is calculated, the displacement is corrected by the image of the board to be inspected, and the corrected image is compared with the image of the master board. Consequently, a decision can be made accurately whether the package component has been mounted properly on the board to be inspected or not even if the board to be inspected is imaged under misregistration state. Since the image of the reference package component and the image of the package component are removed from the first and second images, the displacement can be calculated while preventing the package component, or the like, from causing noise. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mounting component inspection method for imaging a substrate to be inspected on which a mounting component such as a chip resistor or a chip capacitor is mounted, and inspecting the substrate to be inspected based on the image.

This type of conventional mounting component inspection method is described in, for example, Patent Document 1 below. In the mounting component inspection method described in Patent Document 1, a circuit board on which a mounting part is mounted is imaged to acquire the image, and a matching process is performed between the image of the circuit board and reference master data to obtain a difference. The data is detected, and the mounting state of the mounting component is inspected based on the difference data.
Japanese Patent Laid-Open No. 10-150299

  However, in the mounting component inspection method described above, even when the mounting state of the mounting component is appropriate, the difference data is detected due to the displacement of the circuit board with respect to the camera at the time of imaging, and the mounting component is mounted properly. There is a risk of misjudgment that it has not been done.

  Therefore, the present invention has been made in view of such circumstances, and can accurately inspect the mounting state of the mounted component on the board to be inspected regardless of whether the board to be inspected is misaligned during imaging. An object of the present invention is to provide a mounting component inspection method that can be used.

  In order to achieve the above object, a mounting component inspection method according to the present invention is a mounting component inspection method for inspecting a substrate to be inspected on which a mounting component is mounted, and a master on which a reference mounting component serving as an inspection reference is mounted. An area corresponding to the masking area is determined from the master board image based on the process of capturing the board and acquiring the image, the master board image, and the mask image having the mounting component mounting area as the masking area. Corresponding to the masking region from the image of the inspected substrate based on the step of generating the removed first image, the step of capturing the image of the inspected substrate and acquiring the image, and the image of the inspected substrate and the mask image A step of generating a second image from which a region to be removed is removed, a position of at least one first image of a circuit configuration unit and a printing unit provided on the master substrate, and a substrate provided on the substrate to be inspected A step of calculating a misregistration amount between at least one second image of the path forming unit and the printing unit; and correcting the misregistration amount in the image of the inspected substrate, and the inspected substrate after the correction And a step of comparing the image of the master and the image of the master substrate.

  In this mounted component inspection method, the position of at least one of the circuit configuration unit and the printing unit provided on the master substrate in the first image and the at least one first of the circuit configuration unit and the printing unit provided on the board to be inspected. The amount of positional deviation between the positions in the second image is calculated, and the amount of positional deviation is corrected in the image of the substrate to be inspected. Then, in order to compare the image of the substrate to be inspected thus corrected with the image of the master substrate that is the inspection reference, the mounted component on the substrate to be inspected regardless of whether or not the substrate to be inspected is misaligned. It is possible to accurately inspect the mounting state (out of stock, misalignment, etc.). In addition, since the image of the reference mounting component is removed in the first image and the image of the mounting component is removed in the second image, the mounting component that has caused the misalignment is calculated in the misregistration amount calculation step. Noise can be prevented and the processing speed can be improved. Furthermore, in the positional deviation amount calculation process, the circuit configuration part and the printing part provided on the master substrate and the substrate to be inspected are used as the position reference. It is possible to inspect the mounted parts.

  In the step of calculating the positional deviation amount, it is preferable that the circuit component is at least one of a through hole and a wiring pattern. This is because the through-hole and the wiring pattern are almost certainly provided on the master substrate and the substrate to be inspected, so that the first and second images are almost certainly captured and can be used as a position reference.

  As described above, according to the mounting component inspection method according to the present invention, it is possible to accurately inspect the mounting state of the mounting component on the substrate to be inspected regardless of whether or not the substrate to be inspected is displaced at the time of imaging. .

  Hereinafter, a preferred embodiment of a mounting component inspection method according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a mounting component inspection apparatus 1 for carrying out a mounting component inspection method includes a measurement stage 2 for mounting a substrate S to be inspected on which mounting components such as a chip resistor and a chip capacitor are mounted. Have. Above the measurement stage 2, a camera 3 that captures an image of the substrate to be inspected S is installed via a drive mechanism 2 a. Is provided with a ring illumination 4. With such a configuration, the camera 3 is driven in the X-axis direction and the Y-axis direction in a plane parallel to the upper surface of the measurement stage 2 by the drive mechanism 2a, and sequentially images portions to be inspected on the inspected substrate S. I will do it.

  Further, the camera 3 is connected to a processing device 5 for capturing a captured image. The processing device 5 executes various processes based on the image of the board S to be inspected, and determines whether or not the mounting component is properly mounted on the board S to be inspected. Further, a computer 6 as a user interface is connected to the processing device 5, and an input unit 7 such as a keyboard for outputting a signal input by an operator's operation to the computer 6, or the processing device 5. The display unit 8 for displaying the processing result and the like is connected.

  The storage unit of the computer 6 stores reference coordinate data of each mounted component on the board S to be inspected. Here, the reference coordinates are coordinates in the XY coordinate system set on the board S to be inspected, and are coordinates that are targets when mounting components on the board S to be inspected.

  A mounting component inspection method performed in the mounting component inspection apparatus 1 configured as described above will be described.

  First, a first image is generated by removing an area on which a reference mounting component is mounted from an image of a master substrate that is an inspection reference. The first image generation processing by the processing device 5 will be described with reference to the flowchart shown in FIG. First, a portion to be inspected on the master substrate M on which a reference mounting component as an inspection reference is mounted is imaged by the camera 3 and an image A is acquired (step S102). In this image A, as shown in FIG. 3A, in addition to the reference mounting component 15 properly mounted for each reference coordinate αm (m = 1, 2, 3,...), The master substrate M A through hole (circuit component) 16, a wiring pattern (circuit component) 17, and silk-printed characters (printer) 18 provided on the top are imaged. When imaging the master substrate M, the ring illumination 4 is adjusted so that the electrodes 15a provided at both ends of each reference mounting component 15 have a brightness that can be easily distinguished from the cream solder 14 or the like.

  Following the acquisition of the image A, a portion to be inspected on the printed circuit board (unmounted substrate) 11 before mounting the reference mounting component 15 (a portion corresponding to a portion to be inspected on the master substrate M) is captured by the camera 3. The image B is obtained by imaging (step S104). In this image B, as shown in FIG. 3B, the conductive pattern 12 to which the reference mounting component 15 is connected is imaged. Subsequently, the portion to be inspected on the solder printed substrate (solder substrate) 13 on which the cream solder for connecting the reference mounting component 15 to the printed circuit board 11 is printed (corresponding to the portion to be inspected on the master substrate M). A portion to be captured) is captured by the camera 3 to acquire the image C (step S106). In this image C, as shown in FIG. 4A, the cream solder 14 covering the conductive pattern 12 on the printed board 11 is imaged.

  After obtaining the image B and the image C, a difference image D is generated by taking a difference in luminance value for each pixel constituting the image between the two images (step S108). As a result of this processing, the image D has a plurality of solder regions Rn (n = 1, 2, 3,...) Corresponding to the region where the cream solder 14 is applied in the image C, as shown in FIG. Will appear. Subsequently, the data of the reference coordinates αm of each mounted component is read from the storage unit of the computer 6 (step S110).

  Then, two solder regions Rn closest to each reference coordinate αm are selected from the plurality of solder regions Rn, and the component shape is estimated from the shape and interval of the solder regions Rn. A region including two solder regions Rn selected for each reference coordinate αm (ie, a region where a mounting component is mounted for each reference coordinate αm) is designated as a masking region Wm (m = 1, 2, 3,... A mask image E is generated (step S112). For example, in the image D shown in FIG. 4B, the solder areas R1, R7 correspond to the reference coordinate α1, and in the mask image E shown in FIG. 5A, the solder areas R1, R1 are in the XY plane. A rectangular masking region W1 including R7 is a region where the mounting component is mounted with respect to the reference coordinate αm.

  Here, the two solder regions Rn closest to the reference coordinate αm are the solder region Rn closest to the reference coordinate αm and the solder region Rn closest thereto. In addition, as shown in FIG. 5A, the masking region Wm has an outer periphery outside a predetermined amount (dx in the X-axis direction, dy in the Y-axis direction) from the two solder regions Rn selected for each reference coordinate αm. It is an area to have. In generating the mask image E, the masking region Wm is set by taking a predetermined amount dx, dy sufficiently large so as to include the misplaced mounted components in consideration of the misalignment of the mounted components mounted on the board S to be inspected. And

  Subsequent to the generation of the mask image E, the image A of the master substrate M acquired in step S102 is masked with the mask image E, and the first image obtained by removing the region corresponding to the masking region Wm from the image A of the master substrate M. F is generated (step S114). With this processing, in the first image F, as shown in FIG. 5B, the image of the reference mounting component 15 is removed, and the images of the through hole 16, the wiring pattern 17 and the silk print character 18 on the master substrate M are obtained. It will remain. The first image F is stored in the storage unit of the computer 6 and the first image generation process is completed.

  Next, a mounting state (a missing part, a positional deviation, etc.) of the mounting component on the board S to be inspected is inspected. The inspection process of the inspected substrate S by the processing apparatus 5 will be described according to the flowchart shown in FIG. First, the part to be inspected of the inspected substrate S is imaged by the camera 3 and the image G is acquired (step S202). In this image G, as shown in FIG. 7A, in addition to the mounting component 19 that is mounted to be positioned at each reference coordinate αm, a through hole (circuit configuration portion) provided on the inspected substrate S is displayed. ) 16, a wiring pattern (circuit configuration unit) 17, and silk print characters (print unit) 18 are imaged. In the inspected substrate S, the mounted component 19 that has been mounted so as to be positioned at the reference coordinates α1 and α2 is displaced. Also, the mounting component 19 that has been mounted to be positioned at the reference coordinate α3 is missing. When imaging the inspected substrate S, the ring illumination 4 is adjusted so that the electrodes 19a provided at both ends of each mounting component 19 have a brightness that can be easily distinguished from the cream solder 14 or the like.

  Subsequently, the image G is masked with the mask image E generated in step S112, and a second image H is generated by removing the region corresponding to the masking region Wm from the image G of the substrate S to be inspected (step S204). By this processing, in the second image H, as shown in FIG. 7B, the image of the mounted component 19 is removed, and the images of the through hole 16, the wiring pattern 17 and the silk print character 18 on the substrate S to be inspected are obtained. It will remain.

  Then, the first image F generated in step S114 is read from the storage unit of the computer 6 and pattern matching between the first image F and the second image H is performed, so that the master substrate M on the image and the inspection target The amount of positional deviation from the substrate S is calculated (step S206). Specifically, as shown in FIG. 7B, the position of the through hole 16 of the master substrate M in the first image F (shown by a broken line in the figure) and the substrate S to be inspected in the second image H. The positional deviation amount in the X-axis direction and the positional deviation amount in the Y-axis direction are calculated between the through-hole 16 positions. Note that the misregistration amount may be calculated by paying attention to one through hole 16, or the misregistration amount may be calculated as an average value by paying attention to a plurality of through holes 16.

  Subsequently, in the image G of the substrate S to be inspected, the positional deviation amount in the X-axis direction and the positional deviation amount in the Y-axis direction are corrected to generate a position-corrected image J (step S208). In this position correction image J, as shown in FIG. 8, the position of the through hole 16 of the master substrate M in the first image F (indicated by a broken line in the figure) and the substrate S to be inspected in the second image H The positions of the through-holes 16 substantially coincide with each other.

  After this correction, the difference between the brightness value of each pixel constituting the image between the image A of the master substrate M acquired in step S102 and the position-corrected image J is obtained, for example, A comparison with the position correction image J is performed, and it is determined whether or not the mounting component is properly mounted on each reference coordinate αm on the inspected substrate S (step S210), and the inspection processing of the inspected substrate S is completed. Become. Note that if the image A of the master substrate M and the position correction image J are compared by paying attention to the electrodes 15a and 19a having a luminance value higher than the surrounding luminance due to illumination at the time of imaging, the image on the substrate S to be inspected is obtained. Inspection results such as missing parts and misalignment of the mounted component 19 can be obtained with high accuracy and simplicity.

  As described above, in the mounting component inspection method performed by the mounting component inspection apparatus 1, the position of the through hole 16 provided in the master substrate M in the first image F and the through hole provided in the substrate S to be inspected. A displacement amount between the hole 16 and the position in the second image H is calculated, and the displacement amount is corrected in the image G of the substrate S to be inspected. Then, in order to compare the corrected position-corrected image J with the image A of the master substrate M that is the inspection reference, the portion to be inspected of the substrate S to be inspected is imaged in a state shifted from the camera 3. In addition, it is possible to accurately determine whether or not the mounting component is properly mounted on each reference coordinate αm on the inspected substrate S.

  In addition, since the image of the reference mounting component 15 is removed in the first image F and the image of the mounting component 19 is removed in the second image H, in the calculation of the positional deviation amount in step S206, the positional deviation or It is possible to prevent the mounting component 19 that has caused a shortage from becoming noise, and it is possible to improve the processing speed. Further, in the calculation of the positional deviation amount in step S206, since the through hole 16 provided in the master substrate M and the inspected substrate S is used as a position reference, it is not necessary to separately provide a position reference mark or the like. In this way, it is possible to easily inspect mounted components.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the amount of misalignment between the master substrate M and the substrate S to be inspected on the image is calculated using the through hole 16 as a position reference. However, not only the through hole 16 but also the wiring pattern 17 and silk A printed character 18 or the like that can be discriminated in the image can be used as a position reference.

1 is a schematic diagram showing an embodiment of a mounted component inspection apparatus in which a mounted component inspection method according to the present invention is implemented. It is a flowchart which shows the production | generation process of the 1st image by the processing apparatus of the mounting component test | inspection apparatus shown in FIG. It is a schematic diagram which shows the process image in the processing apparatus of the mounting component inspection apparatus shown in FIG. 1, (a) is an image of a master board | substrate, (b) is an image of a printed circuit board. It is a schematic diagram which shows the process image in the processing apparatus of the mounting component inspection apparatus shown in FIG. 1, (a) is an image of the solder printed board | substrate, (b) is the image which extracted the solder area | region. It is a schematic diagram which shows the process image in the processing apparatus of the mounted component inspection apparatus shown in FIG. 1, (a) is a mask image, (b) is a 1st image. It is a flowchart which shows the test | inspection process of the to-be-inspected board | substrate by the processing apparatus of the mounted component inspection apparatus shown in FIG. It is a schematic diagram which shows the process image in the processing apparatus of the mounting component inspection apparatus shown in FIG. 1, (a) is an image of a to-be-inspected board, (b) is a 2nd image. It is a schematic diagram which shows the position correction image which is a process image in the processing apparatus of the mounting component test | inspection apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 15 ... Standard mounting component, 16 ... Through-hole (circuit structure part), 17 ... Wiring pattern (circuit structure part), 18 ... Silk printing character (printing part), 19 ... Mounting part, A ... Image of master board, B ... Image of printed circuit board, C: Image of printed circuit board of solder, D: Image of extracted solder area, E: Mask image, F: First image, G: Image of inspected substrate, H: Second image, J: Position correction image, M: Master substrate, S: Substrate to be inspected, Wm (m = 1, 2, 3,...) ... Masking region.

Claims (2)

A mounting component inspection method for inspecting a substrate to be inspected on which a mounting component is mounted,
Imaging a master board on which a reference mounting component as an inspection standard is mounted and acquiring the image;
Based on the image of the master board and the mask image having the area where the mounting component is mounted as a masking area, a first image is generated by removing the area corresponding to the masking area from the image of the master board. Process,
Imaging the substrate to be inspected and acquiring the image;
Generating a second image obtained by removing a region corresponding to the masking region from the image of the substrate to be inspected based on the image of the substrate to be inspected and the mask image;
The position in the first image of at least one of the circuit configuration unit and the printing unit provided on the master substrate and the second image in at least one of the circuit configuration unit and the printing unit provided on the inspected substrate Calculating the amount of positional deviation between the position,
A mounting component inspection method comprising: correcting the displacement amount in an image of the substrate to be inspected, and comparing the corrected image of the substrate to be inspected with the image of the master substrate. . 2. The mounting component inspection method according to claim 1, wherein, in the step of calculating the positional deviation amount, the circuit component is at least one of a through hole and a wiring pattern.

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