JPH0814844B2 - Inspection device for component mounting board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention processes an image obtained by picking up an image of a substrate to be inspected on which components are mounted to process the presence or absence of a component on the substrate to be inspected, a positional deviation, and the like. The present invention relates to a device for inspecting a component mounting board.

<< Prior Art >> When various chip parts such as resistors and semiconductor elements are mounted on a printed circuit board, when an automatic mounter is used, the parts may not be mounted according to the mounting data after mounting.

Therefore, when using such an automatic mounting apparatus, the printed circuit board is checked after mounting, and a proper chip component is mounted in a proper position (position, direction) at a proper position on the printed circuit board. It is necessary to inspect whether or not there is any dropout.

However, if such an inspection is performed by visual inspection by hand as in the conventional case, there is a problem that the occurrence of an inspection error cannot be completely eliminated and the inspection speed cannot be increased.

Therefore, in recent years, various manufacturers have proposed various automatic inspection devices for printed circuit boards that can automatically perform this type of inspection.

FIG. 9 is a block diagram showing an example of such an automatic inspection apparatus.

The automatic inspection apparatus shown in this figure serves as a reference board as shown in FIG. 10, that is, data input from the TV camera 3 that images the printed circuit board 2-2 on which the component 1 is mounted and the keyboard 8. Data regarding the type of the reference printed circuit board 2-1 and the data regarding the type, arrangement position, mounting posture, shape, etc. of each component 1 mounted on the reference printed circuit board 2-1 and the inspection processing procedure for each of these components 1. The storage unit 4 for storing information (data) regarding the above and the like, and the information stored in the storage unit 4 and the information shown by the image from the TV camera 3 are compared to each other to inspect the printed circuit board 2- 2 includes a determination circuit 5 for determining whether or not all the components 1 are present on the device 2 and whether or not the components 1 are displaced or the like, and a display 6 for displaying the determination result of the determination circuit 5. Ete is configured.

When this automatic inspection device is used, prior to the inspection of the inspected printed circuit board 2-2, first, the data of the reference printed circuit board 2-1 on which the component 1 is correctly mounted on the base board 7 is input from the keyboard 8 ( Teaching).

In this case, as shown in the flow chart of FIG. 11, in this teaching operation, the card number of the reference printed circuit board 2-1 is input from the keyboard 8 at step ST1.

Next, in step ST2, numerical data relating to the position, shape, etc. of the component 1 mounted on the reference printed circuit board 2-1 from the keyboard 8 and the characteristics of the component 1 (this component 1
Information such as color and lightness) and numerical data related to processing procedures are input.

Next, in step ST3, it is checked whether or not the numerical data for all the parts 1 have been input, and if there is a part for which the numerical data has not been input yet, return from this step ST3 to the step ST2 and set the numerical values for the remaining parts. Data input is executed repeatedly.

When the data input for all the components 1 is completed, these numerical data are stored in the storage unit 4 as reference data in step ST4.

When inspecting the inspected printed circuit board 2-2, numerical data obtained from an image of the inspected printed circuit board 2-2 captured by the TV camera and the storage section 4
Numerical data output by is compared by the determination circuit 5, and the comparison result is displayed on the display 6.

If a part of the inspected printed circuit board 2-2 imaged by the TV camera 3 is missing, the TV
The numerical data obtained based on the image output by the camera 3 and the numerical data output by the storage unit 4 do not match, and the determination circuit 5 detects this and displays the missing parts on the display 6. To display.

<< Problems to be Solved by the Invention >> However, in such a conventional automatic inspection device, if it is attempted to increase the inspection accuracy by increasing the number of numerical data serving as a determination reference, the keyboard 8 is used during teaching. There is a problem in that the number of data that must be input increases, and it takes a lot of time and labor to input the data.

In addition, since the same inspection is performed on any of the components 1 on the inspected printed circuit board 2-2, if the inspection accuracy is to be increased, the number of determinations will increase and a great amount of time will be required for the determinations. There was a problem.

In view of the above circumstances, the present invention can obtain the optimum inspection accuracy according to the characteristics of each component without increasing the number of input data at the time of teaching, thereby shortening the determination time at the time of inspection. It is an object of the present invention to provide an inspection device for a component mounting board, which can perform the inspection accurately according to the characteristics of each component.

<< Means for Solving Problems >> In order to solve the above problems, in the component mounting board inspection apparatus according to the present invention, the board information of the board on which the parts are mounted is processed to mount the parts on the board. In a component mounting board inspection device for inspecting a state, processing means for processing the board information is hierarchized according to a stage of inspection accuracy, and processing of the part information is performed according to a state of the part information in the board information. By changing the step of the means, a processing unit for processing information on the component on the substrate is provided.

<< Embodiment >> FIG. 1 is a block diagram showing an embodiment of an inspection apparatus for a component mounting board according to the present invention.

The component mounting board inspection apparatus shown in this figure captures and processes the reference printed circuit board 16-1 to determine each component necessary for determining the quality of the inspected printed circuit board 16-2.
A reference parameter for each of 19-1 to 19-n and a processing procedure for each of the components 19-1 to 19-n necessary to obtain each of these reference parameters are obtained. Y table unit 10, image pickup unit 11, processing unit 12, determination result output unit 26, information input unit 27, table controller 29,
And an image pickup controller 30.

The XY table unit 10 includes two pulse motors 13 and 14 controlled by a table controller 29, and a table 15 driven by the pulse motors 13 and 14 in the X-axis direction and the Y-axis direction. And the reference printed circuit board 16-1 and the inspected printed circuit board 16-mounted on the table 15.
2 and the check mechanism 17 for fixing the reference print circuit board 16-1 (or the printed circuit board 16-2 to be inspected) placed on the table 15 by the check mechanism 17. After being fixed, the positions in the X-axis direction and the Y-axis direction are determined by the pulse motors 13 and 14, and the image is picked up by the image pickup unit 11.

In this case, the reference printed circuit board 16-1 is provided with a base board 18 as shown in FIG.
-1 to 19-n are placed in the correct position and in the correct posture.

The printed circuit board 16-2 to be inspected is a mass-produced board having the same base substrate 18 as the reference printed circuit board 16-1, and the component 19-on the reference printed circuit board 16-1 is mounted on the base substrate 18. Parts 19-1 to 19 to be the same as 1 to 19-n
-N is placed.

Further, the image pickup unit 11 is arranged above the XY table unit 10, and its focus, magnification, sensitivity and the like are controlled by a control signal output from the image pickup controller 30.
20 and a ring illumination device 21 that is disposed coaxially with respect to the TV camera 20 and whose brightness and the like are controlled by a control signal output from the imaging controller 30, and is configured. The image signal (analog signal) obtained by the TV camera 20 is supplied to the processing unit 12.

In the teaching mode, the processing unit 12 receives the image signal (the reference printed circuit board 16) supplied from the image pickup unit 11.
-1 image signal) hierarchical processing means (processing hierarchy)
Processing is performed to find suitable processing means for each of the components 19-1 to 19-n on the basis of waiting for the components 19-1 to 19-n on the reference printed circuit board 16-1. Is stored as a processing procedure file, and the parameters (reference parameters) of the respective parts 19-1 to 19-n obtained by processing the image signals by the respective optimum processing means are stored as a reference parameter file. .

In the inspection mode, the processing unit 12 supplies the image signal supplied from the image pickup unit 11 based on the optimum processing means for each of the components 19-1 to 19-n indicated by the processing procedure file. The parameters (inspected parameters) of each of the components 19-1 to 19-n are extracted from (the image signal of the inspected printed circuit board 16-2) and compared with the reference parameters of the reference parameter file. The image input unit 22, the image processing unit 23, and the image input unit 22 determine whether or not each of the components 19-1 to 19-n on the inspected printed circuit board 16-2 has fallen off or displaced. Memory 24 and determination unit 25
And a control unit 28.

The image input unit 22 performs A / D conversion of the image signal supplied from the image pickup unit 11 and performs various correction processes (for example, shading correction) to perform the correction processing on the reference printed circuit board 16-1. Image data of the inspection printed circuit board 16-2 (data obtained by correcting and quantizing the image signal) is created, and the images of the reference printed circuit board 16-1 and the inspected printed circuit board 16-2 obtained here are obtained. Data is the control unit
Supplied to 28 etc.

Further, the image processing unit 23 has a processing procedure in which the first to m-th processing means are hierarchized. In the teaching mode, the window information supplied from the control unit 28 and the processing procedure are Is used to process the image data of the reference printed circuit board 16-1 supplied via the control unit 28, so that the components 19-1 to 19-n mounted on the reference printed circuit board 16-1 are processed. The optimum processing means is obtained for each of them, and these are supplied to the control unit 28 as a processing procedure file, and each of the parts 19-1 to 19-n obtained by processing by these optimum processing means is obtained. The parameters (reference parameters) are collected and supplied to the control unit 28 as a reference parameter file.

In this case, as the first processing means, for example, a normal binarizing process or the like is used.

Further, as the second processing means, a processing which is more complicated and takes a longer time than the first processing means, for example, a minute pixel removing processing or a hole filling processing is used. Similarly, the third to mth
As the processing procedure of, the processing that is more complicated and time-consuming than the second processing means is sequentially used.

Further, the image processing unit 23, in the inspection mode, based on the window information, the procedure file, and the like,
Printed circuit board 16 to be inspected supplied via the control unit 28.
-2 image data is processed by an optimum processing means for each of the components 19-1 to 19-n, and the parameters (components to be inspected) of the components 19-1 to 19-n on the inspected printed circuit board 16-2 are processed. Parameter) is extracted, and a parameter file to be inspected is collectively created and supplied to the control unit 28 and the like.

Further, the memory 24 includes the image data of the reference printed circuit board 16-1, the image data of the printed circuit board 16-2 to be inspected, and the parts on the reference printed circuit board 16-1 from the control unit 28.
When the parameters 19-1 to 19-n (reference parameters), position data, shape data, window information, processing procedure file, etc. are supplied, they are stored, and a transfer request is sent from the control unit 28. At the time of collection, the reference parameters and the like are supplied to the image processing unit 23, the determination unit 25 and the like.

The determination unit 25 compares the reference parameter output by the memory 24 in the inspection mode with the inspection parameter obtained by the image processing unit 23 supplied via the control unit 28, and determines the inspection target. Inspection printed circuit board 16-2 parts 19-1 to 19-1
19-n is missing and these parts 19
It is to determine whether or not -1 to 19-n have a posture deviation, and the determination result is supplied to the control unit 28 and the like.

The control unit 28 also creates windows 31-1 to 31-n as shown in FIG. 3 from the position data and shape data of each of the components 19-1 to 19-n input from the information input unit 27. , This is stored in the memory 24 as window information,
It controls the image input unit 22, the image processing unit 23, the memory 24, and the determination unit 25 in 12 to operate them in the teaching mode or the inspection mode. The data obtained in each mode is supplied to the determination result output unit 26 and the like.

The determination result output unit 26 is configured to include a CRT (cathode ray tube display), a printer, etc., and is supplied with a reference parameter or an inspected parameter from the control unit 28,
When the image data of the reference printed circuit board 16-1 or the inspected printed circuit board 16-2 is supplied or the determination result is supplied, this is displayed or printed out.

In addition, the information input unit 27 includes the type (for example, the board number) of the reference printed circuit board 16-1 and the types, the number of parts, and the positions of the components 19-1 to 19-n mounted on the reference printed circuit board 16-1. It is equipped with a keyboard and a mouse for inputting data related to shapes, etc. and operation information for determining processing procedures, etc., and is also equipped with a monitor, a printer, etc. for confirming the input data, operation information, etc. The data and operation information input from here are supplied to the control unit 28.

The table controller 29 is configured to include an interface or the like that connects the control unit 28 and the XY table unit 10 to each other.
The data obtained in step 3 is supplied to the control unit 28, and the XY table unit 10 is controlled based on the control signal supplied from the control unit 28.

In addition, the image pickup controller 30 is configured to include an interface or the like that connects the control unit 28 and the image pickup unit 11, and controls the image pickup unit 11 based on a control signal supplied from the control unit 28. To control.

Next, the operation of this embodiment will be described separately for the teaching mode and the inspection mode. In addition, in the following description, for simplification of description, the first and second processing means will be described, and the description of the third to mth processing means will be omitted.

First, in the teaching mode, the flow chart step ST5 shown in FIG. 4 (A) is executed to set each part of the apparatus to the teaching mode, and at the step ST6, the information input section 27 to the reference printed circuit board 16-1 A number and position data and shape data of each of the components 19-1 to 19-n mounted on the reference printed circuit board 16-1 are input.

Then, when each of these data is input, the control unit 28 stores the board number and the like in the memory 24 in step ST7, and for each component 19-1 to 19-n based on the position data and the shape data. Windows (data cutout windows) 31-1 to 31-n shown in FIG. 3 are created and stored in the memory 24 as window information. In this case, each of the windows 31-1 to 31-n has a corresponding component 19-1 to 19-n.
It is made to circumscribe -n or surround the outside by about 1.5 mm.

After this, if the reference printed circuit board 16-1 is placed on the table 15 of the XY table section 10, the control section 28 will step.
In ST8, the check mechanism 17 is operated to fix the reference printed circuit board 16-1 and the pulse motors 13, 1
4 is operated to determine the position of the reference printed circuit board 16-1 in the X-axis direction and the position of the Y-axis direction, and adjust the brightness of the ring illumination device 21 and the imaging condition of the TV camera 20.

Next, in step ST9, the control unit 28 controls the image input unit 22 to the determination unit 25 while causing the TV camera 20 to take an image of the reference printed circuit board 16-1 and the reference print obtained by the TV camera 20. The image signal of the substrate 16-1 is converted into image data by the image input unit 22, and the conversion result (reference substrate image data) is stored in the memory 24.

Next, in step ST10, the control unit 28 sends the reference board image data in the memory 24 and the window information to the image processing unit.
Then, the image processing section 23 is caused to execute the parameter extraction routine 42.

In this parameter extraction routine 42, the image processing unit 23
First, the flow chart step ST11 shown in FIG. 4 (B).
In each of the windows 31-
Each part from the reference board image data using 1 to 31-n
The part images of 19-1 to 19-n are cut out, and at step ST12, the part number data N in the memory (memory in the image processing unit 23) is set to N = 0. After that, the image processing unit 23 causes the determination result output unit 26 to display each of the component images in step ST13.

In this case, if the component image S1 included in the image signal is sharp as shown in the waveform diagram of FIG. 5, the determination result output unit 24 clearly shows the edge of the component as shown in FIG. 6 (A). If the component image S-1 is displayed and the component image S1 included in the image signal has a deteriorated SN ratio as shown in the waveform diagram of FIG. As shown in FIG. 3A, a noisy component image S1-3 is displayed.

After that, in step ST14, the image processing unit 23 displays a message sentence on the determination result output unit 26 and asks the operator whether there is a component to be processed.

Then, if this operator inputs information indicating that there is an unprocessed part through the information input unit 27, the image processing unit 23 detects this in step ST15, and this step ST15
The process branches from step 15 to step ST16, where the part number data N is incremented and step ST17
Then, a message sentence is displayed on the determination result output unit 26 to ask the operator how to binarize.

Then, when the operator instructs the binarization by the fixed threshold value via the information input section 27, the image processing section 23 detects this at step ST18, and branches from this step ST18 to step ST19. The parameter is binarized with a fixed threshold that has been determined, the binarization result is displayed on the determination result output unit 26, and then the process proceeds to step ST22.

Further, if the operator instructs the binarization by the mode method via the information input unit 27, the image processing unit 23 causes the step to be performed.
From ST18 to step ST20, the component image is binarized by a threshold value obtained from the value of the valley point when each pixel of the component image is histogrammed, and the binarization result is output as a determination result. After displaying it on the section 26, proceed to Step ST22.

Further, when the operator instructs the binarization by the P tile method through the information input unit 27, the image processing unit 23 branches from the step ST18 to the step ST21, and the area (or The component image is binarized by a threshold value obtained from the value of the number of pixels, etc., and the binarization result is displayed on the determination result output unit 26, and then the process proceeds to step ST22.

In this case, if the component image S1 included in the image signal is sharp as shown in the waveform diagram of FIG. 5, the determination result output unit 26 displays the component image S1-2 shown in FIG. 6 (B). Is
If the component image S1 included in the image signal has a deteriorated SN ratio as shown in the waveform chart of FIG. 7, the determination result output unit 26 displays the component image S1-4 shown in FIG. Is displayed.

Then, if the operator who has seen the component image displayed on the determination result output unit 26 indicates through the information input unit 27 that there is no need for noise removal, the image processing unit 23 does this in step ST22. It is detected and the process branches from this step ST22 to step ST26. That is, in this case, the first
Only the process 50 of the hierarchy is executed and the process 51 of the second hierarchy is skipped.

Further, in the step ST22, the operator determines that noise removal is necessary, and through the information input unit 27,
The image processing unit 23 branches from this step ST22 to step ST23 by instructing the filling processing of the largest area among the component images displayed on the determination result output unit 26, and FIG.
After extracting the maximum area image (maximum component image) S1-5 in the component image shown by the component image S1 as shown in FIG.
If there is a hole (bit missing, block missing) in this maximum component image S1-5, this maximum component image S1− in step ST24.
The padding processing of No. 5 is performed, and as shown in FIG. 8D, the processing result (part image) S1-6 is displayed on the determination result output unit 26, and the process proceeds to step ST26.

Further, in step ST22, the operator determines that noise removal is necessary, and indicates the minute object removal processing in the component image S1-3 displayed in the determination result output unit 26 via the information input unit 27. For example, the image processing unit 23
Branch from ST22 to step ST25 to display the parts image S1-3
The minute object in the component image indicated by is removed, and the removal result (component image) is displayed on the determination result output unit 26.

Then, in step ST26, the image processing unit 23 displays a message sentence on the determination result output unit 26 and asks the operator whether or not the component processing should be redone.

Then, if the operator indicates via the information input unit 27 that the process needs to be redone, the image processing unit 23 detects this in step ST27, and from this step ST27 to step ST18. Returning to this, the above-mentioned processing is executed again for this part.

Further, here, if the operator indicates through the information input unit 27 that it is not necessary to perform the above-mentioned processing again for this component, the image processing unit 23 stores the last-obtained image as a reference parameter and , The processing performed on this part is stored as the optimum processing means, and then the processing is branched from the step ST27 to the step ST14 and the above-mentioned processing is performed on the remaining parts, and the inspection accuracy of each part is improved. A corresponding optimum processing means and a binarized image (reference parameter) are obtained.

Then, if the optimum processing means and the reference parameter are obtained for each of the components 19-1 to 19-n, the image processing unit 23 determines the optimum processing means for each of the components 19-1 to 19-n in step ST28. The processing procedure file described above is created and stored in the memory 24. Further, in the inspection mode, the control unit 28 sets the fourth
After the step ST30 of the flow chart shown in FIG. 7C is executed to set each part of the apparatus to the inspection mode, the window information and the processing procedure file stored in the memory 24 are stored in the image processing section 23 in step ST31. Transfer to
The reference parameter file stored in the memory 24 is transferred to the determination unit 25.

Next, when the inspected printed circuit board 16-2 is placed on the table 15 of the XY table section 10, the control section 28 operates the check mechanism 17 in step ST32 to move the inspected printed circuit board 16-2. Fixed, then each pulse motor 1
3, 14 are controlled to determine the position of the printed circuit board 16-2 in the X-axis direction and the position of the Y-axis direction, and the brightness of the ring illuminator 21 and the imaging conditions of the TV camera 20 are adjusted.

Next, the control unit 28 controls the TV camera 20 in step ST33.
The printed circuit board 16-2 to be inspected is imaged, and the image input section 22 is operated to obtain image data (image of the inspected board image) from the image signal of the inspected printed circuit board 16-2 obtained by the TV camera 20. Data) is created and stored in the memory 24.

Next, the control unit 28 transfers the inspected board image data to the image processing unit 23 in step ST34, and the image processing unit 23
In 23, the component image of each component 19-1 to 19-n is cut out from the inspected substrate image data based on the window information, and the process indicated by the processing procedure file in step ST35, that is, for each component, is performed. Then, each part image is processed by each optimum processing means, and the binarized part image (inspected parameter) of each part is extracted.

Next, the control unit 28 causes the inspected parameter file to be created from these inspected parameters in step ST36, and also transfers this to the determination unit 25 so as to transfer the inspected parameter file.
Compared with the reference parameters for 19-1 to 19-n,
Whether or not the components 19-1 to 19-n of the inspected printed circuit board 16-2 are missing, and these components 19-1 to 19-n
It is determined whether or not the posture has been misaligned, and in step ST37, this determination result is supplied to the determination result output unit 26 and displayed.

In the embodiment described above, the image processing unit 23 and the determination unit 25 perform image processing and parameter determination processing. However, the processing performed by the image processing unit 23 and determination unit 25 is performed by the control unit 28. You may make it do with the program of.

Further, in the above-described embodiment, one window is provided for one component, but even if one component has different features, a plurality of components are provided for one component. A window may be provided and parameters may be extracted for each window.

Further, as described above, in the embodiment, the binarization parameter extraction process is hierarchized, but the shape recognition process, the position recognition process, the component presence / absence determination process, the color process, etc. may be hierarchized.

Further, as described above, in the embodiment, whether or not to proceed from the first processing layer to the next processing layer is determined by the operator's judgment, but it is possible to automate this by using a judgment criterion expression or the like. May be.

<< Effects of the Invention >> As described above, according to the present invention, it is possible to obtain optimum inspection accuracy according to the characteristics of each component without increasing the number of input data during teaching, and to make a determination during inspection. The time can be shortened and it can be inspected accurately according to the characteristics of each component.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the component mounting board inspection apparatus according to the present invention, FIG. 2 is a plan view showing an example of a reference printed circuit board used in this embodiment, and FIG. 3 is this embodiment. FIG. 4 (A) is a flow chart showing an example of the teaching operation of this embodiment, and FIG. 4 (B) is an extraction of parameters used in the teaching operation of this embodiment. A flow chart showing an example of the routine, FIG. 4 (C) is a flow chart showing an example of the inspection operation of this embodiment, and FIG. 5 is a schematic diagram showing the waveform diagram of the component image signal in this embodiment, and FIG. 8A and 8B are schematic diagrams for explaining an example of processing the component image signal shown in FIG. 5, FIG. 7 is a schematic diagram showing another waveform example in this embodiment, and FIG. ) ~ (D)
Are schematic diagrams for explaining processing examples of the component image signals shown in FIG. 7, FIG. 9 is a block diagram showing an example of this conventional automatic inspection device, and FIG. 10 is an inspection standard of this automatic inspection device. FIG. 11 is a side view showing an example of a reference printed circuit board that serves as the reference printed circuit board, and FIG. 11 is a flow chart showing an example of the teaching operation of this automatic inspection apparatus. 11 ... Imaging unit, 12 ... Processing unit, 16-1 ... Reference board (reference printed board), 16-2 ... Inspected board (Inspected printed board), 18 ... Element board, 19-1 to 19-1 19-n …… Parts.

Claims (1)

[Claims] 1. In a component mounting board inspection apparatus for processing board information of a board on which a component is mounted to inspect a mounting state of a component on the board, the processing means for processing the board information is a step of inspection accuracy. According to the state of the component information in the board information, the processing unit for processing the component information is changed according to the state of the component information, and the processing unit for processing the information on the component on the board is provided. Characteristic component mounting board inspection device.