JPS62188946A - Inspection apparatus for part packing circuit board - Google Patents

Abstract

PURPOSE:To obtain a color image of a circuit board without use of a costly color TV camera, by providing a plurality of cameras at a photographing section for taking different color images of the circuit board. CONSTITUTION:In the inspection mode, a control section 36 shifts parts of the apparatus to this mode and types or the like of feature parameters stored into a memory 34 are transferred to an image processing section 33 and a judging section 35. Then, when a reference printed circuit board 25-2 is placed on a table 24 at an X-Y table section 15, the control section 36 operates a chuck mechanism to fix the circuit board 25-2. Then, pulse motors 22 and 23 are controlled to determine the X- and Y-axis positions of the circuit board 25-2 while the brightness of a lighting device 30 and photographing conditions of monochromatic TV cameras 42 and 43 are adjusted. Then, the control section 36 makes the camera 42 and 43 take the circuit board 25-2 while allowing the image input section 32 to take in a GB primary color signal to generate a GB primary color image data.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention processes an image obtained by capturing an image of a board to be inspected on which components are mounted to determine the presence or absence of components on the board, positional deviation, etc. The present invention relates to a component mounting board inspection device for inspection.

(Prior art) When an automatic mounting device is used to mount various chip components such as resistors and half-body elements on a printed circuit board, the components may not be mounted according to the mount data after mounting. There is.

Therefore, when using such automatic mounting equipment, the printed circuit board is checked after mounting to ensure that the correct chip components are mounted in the correct position and orientation (position and direction) on the printed circuit board. Whether there is
It is also necessary to inspect whether or not it has fallen off.

However, if such an inspection is performed by manual visual inspection as in the past, there are problems in that the occurrence of inspection errors 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. 8 is a block diagram showing an example of such an automatic inspection device.

The automatic inspection device shown in this figure includes a color TV camera 3 that captures images of a printed circuit board 2-2 to be inspected on which a component 1 is mounted and a reference printed circuit board 2-1 that serves as an inspection standard; a storage unit 4 that stores a color image (reference color image) of the reference printed circuit board 2-1 that has been inspected; Compare the color image of the printed circuit board 2-2 (color image to be inspected) to check whether all the components 1 are present on the printed circuit board 2-2 and whether these components 1 are misaligned, etc. The device includes a determination circuit 5 that determines whether or not a problem is occurring, and a display 6 that displays the determination result of the determination circuit 5.

(Problems to be Solved by the Invention) However, such a conventional automatic inspection device requires an expensive color TV camera, so there is a problem that the device itself becomes expensive.

In view of the above circumstances, the present invention makes it possible to obtain a color image of a substrate without using an expensive color TV camera.
It is an object of the present invention to provide a component-mounted board inspection device that can reduce the cost of the device itself.

(Means for Solving the Problems) In order to solve the above problems, the component mounting board inspection apparatus according to the present invention performs a comparison operation between multiple color images obtained by imaging a board on which components are mounted. A component mounting board inspection device for inspecting components on the board by applying
The present invention is characterized in that the imaging section for imaging the substrate is provided with a plurality of decoy imagers that illuminate images of different colors.

(Example) First, prior to a detailed description of the present invention, a component inspection method used in this example will be explained.

First, what is generally referred to as color is the hue.
It is classified into brightness and saturation.

Then, as in the conventional inspection method, the printed circuit board to be inspected is photographed using a color TV camera, and the R obtained at that time is
In the case where only one of the primary color signal, G primary color signal, and B primary color signal is used, for example, only the R primary color signal, even if the color of the background element substrate is red, which takes one value in the red region, for example, If the color of the part is an achromatic color with the same brightness as this red color, as is clear from the Munsell color chart shown in Figure 6, they will have the same brightness, so even if the color of the part is gray (
Even when using an achromatic color (one of the achromatic colors with only brightness from white to black), the level of the background elemental board part and the level of the 1yl wiring part in the R primary color signal output by the color TV camera are the same. Therefore, it is not possible to distinguish between them.

Therefore, in this embodiment, as described below, even if the color of the component mounted on the board and the color of the base board are similar, it is possible to detect the presence or absence of one item9 positional shift, etc. ing.

First, in a chromaticity diagram in which the XYZ color system is expressed in X-Y as shown in Figure 7, if we express the function X-Y=, then
This passes through the point at the value of the Y axis (axis corresponding to the G primary color signal) and intersects the spectrum locus 13 at an angle of 45 mm with the X axis (axis corresponding to the R primary color signal). It becomes a straight line.

Therefore, the R primary color signal output by the color TV camera,
By subtracting the G primary color signal from the R primary color signal of the G primary color signal and the B primary color signal, that is, the RG subtracted video signal, and converting this into 2IN using the constant K, the specs 1 to 1 are obtained. It is possible to binarize the portion of the curve locus 13 above and below the function X-Y= with the level K as the center.

In other words, in this example, a board painted green with an appropriate stimulus purity is used, and if the component is not green, even if it is achromatic, the R signal obtained by subtracting the G primary color signal from the R primary color signal is used. This method takes advantage of the fact that a component image can be extracted by using a -G reduced tube video signal or a G-R subtracted video signal obtained by subtracting an R primary color signal from a G primary color signal.

For the same reason, G
It is recognized that if a subtracted video signal of -8 or BG is obtained, it is possible to selectively extract parts of any color other than yellow.

Note that colors can be selectively identified using arithmetic expressions other than these arithmetic expressions.

And in this embodiment, two image carriers (for example,
By using a monochrome TV (monochrome TV camera, line sensor, etc.) and providing different optical filters in front of the lens of these image carriers, it is possible to obtain a color image of the substrate without using a color TV camera.

Next, a component mounting board inspection apparatus according to the present invention using the above-described component detection method will be specifically described.

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

The component mounting board inspection equipment shown in this figure uses an Il imager 7 that produces a G (green) image, and an image carrier 8 that produces an 8-color (blue) image to produce a yellowish image. painted,
The G-8 subtracted video signal (or B-G subtracted video signal) is obtained from the G primary color signal and the B primary color signal obtained by imaging the printed circuit board. It is designed to be able to extract component images, and includes an X-Y table section 15 and an image forming section 1.
6, the processing unit 17, the determination result output unit 18, the information input unit 19, the table controller 2o, and the imaging control unit 0
- La 21.

The X-Y table section 15 includes two pulse motors 22.23 controlled by a table controller 20, a table 24 driven in the X-axis direction and the Y-axis direction by each of these pulse motors 22.23, and this table. A chuck machine tIA2 that fixes the reference printed circuit board 25-1 and the printed circuit board to be inspected 25-2 placed on the section 24.
6, and the table 24
The reference printed circuit board 25-1 (also the printed circuit board to be inspected 25-2) placed thereon is fixed by the chuck mechanism 26, and then moved in the X-axis direction and the Y-axis direction by each of the pulse motors 22.23. is determined and converted into a wt image by the ridge image section 16.

In this case, the reference printed circuit board 25-1 includes a base board 27 colored yellow as shown in FIG.
8-1 to 28-n are placed in the correct position and in the correct posture.

Further, the printed circuit board 25-2 to be inspected is mounted on a base board 27 colored in the same manner as the base board 27 constituting the reference printed circuit board 25-1.
It is an opening board in which parts 28-1 to 28-n are arranged so as to be the same as parts 28-1 to 28-0 above, and is compared with the reference printed board 25-1 during inspection,
It is determined whether the quality is good or bad.

The whisker image section 16 is arranged above the X-Y table section 15, and includes two images 117.8 whose focus, magnification, sensitivity, etc. are controlled by control signals output from the image pickup controller 21, and the reference image 117.8. a light splitter 9 which divides the light from the printed circuit board 25-1 (or the printed circuit board to be inspected 25-2) into two and supplies each to the 11 imagers 7.8; and a control signal outputted by the imaging controller 21. A lighting device 30 whose brightness, etc., is controlled by the lighting system.

In this case, the optical distributor 9 is the reference printed circuit board 25-1.
(or a half mirror that transmits the image from the printed circuit board 25-2 to be inspected) and supplies it to the 1111 aircraft 7;
The image reflected by this half mirror is captured in the image pickup 81.
8.

Further, the II imager 7 is equipped with a monochrome TV camera 42 and a 0-color filter 44 provided in front of the lens of the monochrome TV camera 42, and a reference printed circuit board 25- which is supplied via the light distributor 9. 1 (or the printed circuit board to be inspected 25-2>), and supplies this to the processing section 17 as a G primary color signal.

Further, the imaging IR 8 includes a monochrome TV camera 43 and an IR 8 provided in front of the lens of the monochrome TV camera 43.
It is equipped with a color filter 45, and extracts eight-color images from images from the reference printed circuit board 25-1 or the printed circuit board 1 to test board 25-2) supplied via the light distributor 9. This is supplied to the processing section 17 as eight primary color signals.

In the teaching mode, the processing section 17 converts the G primary color signal (No. 5) and the B primary color signal (color image of the printout 25-1) supplied from the image section 16 to the G-
B's decrease n bidet A Buddhist name is created, and this G-B decreases bidet A
Characteristic parameters (parameters) of the parts 28-1 to 28-n are extracted and stored based on the Shingetsu, and in the inspection mode, the G primary color signal and B primary color signal ( A G-8 subtraction video signal is created from the color image of the printed circuit board 25-2 to be inspected, and this G-8 subtraction video signal is
- parts 28-1 to 28- based on the subtracted video signal of B.
After extracting n characteristic parameters (parameters to be inspected), this parameter to be inspected is compared with the reference parameter, and based on the comparison result, the printed circuit board to be inspected 25-
2, and is composed of an image input section 32, an image processing section 33, a memory 34, a judgment section 35, and a control section 36.

The image input section 32 performs A/D conversion on the G primary color signal and the B primary color signal supplied from the imaging section 16, performs various correction processes (for example, shading correction, etc.),
G3 primary color image data of the board 25-1 (or the printed circuit board to be inspected 25-2) is created for the reference printed circuit board 1, and the image data of the reference printed circuit board 25-1 (or the printed circuit board to be inspected) obtained here is The GB primary color image data covered on the printed circuit board 25-2) is supplied to the control section 36 and the like.

Further, the image processing section 33 creates a G-B subtraction video signal from the GBI 1m color image data supplied via the I11 control section 36, and converts this G-B subtraction video signal into levels O to 256. After normalization, part 28-
This method identifies the colors of parts 1 to 28-n and the color of the base substrate 27, and extracts the characteristic parameters (reference parameters or parameters to be inspected) of these parts 28-1 to 28-0. The characteristic parameters related to the reference printed circuit board 25-1 (or the inspected printed circuit board 25-2) are supplied to the control section 36 and the like.

In this case, the characteristic parameters include each of the parts 28-
A total sum value of each pixel obtained by processing the component image obtained by cutting out the G-B subtracted video signal using a window (data acquisition window) provided in 1 to 28-nffi according to the processing procedure, Parameters necessary to determine the presence or absence of a component, such as zero position deviation, are used, such as the average value obtained by dividing this total sum W value by the number of pixels.

Further, the memory 34 is supplied with files of characteristic parameters (reference parameters), window information, processing procedure files, etc. regarding each component 28-1 to 28-n on the reference printed circuit board 25-1 from the control unit 36. When there is a transfer request from the control unit 28, these reference parameter processing procedure files are supplied to the determination unit 35, image processing unit 33, etc.

The determination unit 35 compares the reference parameters outputted by the memory 34 in the inspection mode with the parameters to be inspected, which are supplied via the control unit 36 and are extracted by the image processing unit 33, and determines the parameters to be inspected. This is to determine whether the parts 28-1 to 28-n of the inspected printed circuit board 25-2 are defective or not, and whether these parts 28-1 to 28-n have misaligned positions. , this determination result is supplied to the control unit 36 and the like.

The control section 36 controls the image input section 32, the image processing section 33, the memory 34, and the determination section 35 to operate them in a teaching mode or in an inspection mode.

Further, the judgment result output unit 18 is configured with a CRT (cathode ray tube display), a printer, etc., and is supplied with reference parameters and inspected parameters from the control unit 28, and outputs the reference printed circuit board 25-1. (or when the GB primary color image data of the printed circuit board 25-2 to be inspected) or the determination result is supplied, it is displayed or printed out.

The information input unit 19 also inputs information such as the type of the reference printed circuit board 25-1 (for example, the board number, etc.), the type 1 position, shape, etc. of the components 28-1 to 28-n mounted on the reference printed circuit board 16-1. It is equipped with a keyboard and mouse for inputting data and operational information such as processing procedures, and a monitor, printer, etc. for checking the input data and operational information. The generated data, operation information, etc. are supplied to the control unit 36.

Further, the table controller 20 is configured with an interface etc. that connects the front 2 control section 36 and the X-Y table section 15, and uses the data obtained from the X-Y table section 15 to control the 36, and controls the XY table section 15 based on the control signal supplied from the control section 36.

Further, the imaging controller 0-21 is connected to the control section 36 and the front &!
The front image storage unit 16 is configured to include an interface for connecting with the image storage unit 16, and controls the front image storage unit 16 based on control signals supplied from the control unit 36.

Next, 1llfl of this embodiment will be explained by dividing it into a teaching mode and an inspection mode.

First, in the teaching mode, in step ST1 of the flowchart shown in FIG. 3(A), the control unit 36 puts each part of the apparatus into the teaching mode.

Next, in step ST2, the control section 36 inputs the type of reference printed circuit board 25-1 and the types of components 28-1 to 28-n mounted on this reference printed circuit board 25-1 through the information input section 19. 1. Data regarding the position, shape, processing procedure, etc. are taken in, and in step ST3, each part 28-1 is
Winds 40-1 to 40 circumscribing edges of ~28-n
-n (see FIG. 4), and use this as window information for the type 9 component 28-1 of the reference printed circuit board 25-1.
~28-n are stored in the memory 34 together with data regarding the type, treatment procedure, and customer.

After that, when the reference printed circuit board 25-1 is placed on the table 24 of the By controlling the motors 22 and 23, the X of the reference printed circuit board 25-1 is
In addition to determining the axial position and Y-axis position, the brightness of the lighting device 30 and the monochrome TV camera 42.43
Adjust the layer image conditions.

Next, the control unit 36 controls the monochrome T in step ST5.
Reference printed circuit board 25-1 by V camera 42.43
As well as using these monochrome DTV cameras 4
The reference printed circuit board 25- obtained by 2.43
The G primary color signal and the B primary color signal of No. 1 are taken into the image input section 32 to create G3 primary color image data.

Next, the control unit 36 controls the method 34 in step ST6.
1 to the image processing unit 33 for window information, processing procedures, etc.
In addition to transferring the data to I, the image human power^1
The GB primary color image data obtained in step 32 is transferred to the image processing unit 33, and GB[1' is processed from the color image data using each window 40-1 to 40-'1 indicated by the window information. The GB primary color image of each part 28-1 to 28-n is cut out to extract a color part image.

After this, the control unit 36 controls the image processing unit 33 in step ST7.
Then, eight primary color signals are subtracted from the G primary color signal constituting the color component image to create a G-8 subtracted video signal.

Next, in step ST8, the control section 36 instructs the image processing section 33, based on the processing procedure, on the colors of the components 28-1 to 28-0 in the G-B reduced power video signal and the base substrate 27.
, and extract the characteristic parameters (reference parameters) of these parts 28-1 to 28-n, and in step ST9 create a parameter file in which the numbers of these characteristic parameters and their types are recorded. , this is stored in the memory 24.

In addition, in the case of an inspection need, in step ST10 of the flowchart shown in FIG. The type of parameter, data related to the processing procedure, window information, etc. are transferred to the image processing section 33, and the values of each characteristic parameter in the parameter file are transferred to the determination section 35.

Next, when the reference printed circuit board 25-2 is placed on the table 24 of the X-Y table section 15, the control section 36 fixes the reference printed circuit board 25-2 with the chuck mechanism 26 in step 5T12, and then each pulse By controlling the motors 22 and 23, the X of the reference printed circuit board 25-2 is
In addition to determining the axial inner position δ and the Y-axis direction position, the brightness of the lighting device 30 and the monochrome TV camera 42.43
Adjust the imaging conditions.

Next, in step 5T13, the control unit 36 detects the printed circuit board 25 to be inspected using the monochrome TV camera 42, 43.
-2 and this monochrome TV camera 4.
The printed circuit board 25 to be inspected obtained by 2.43
-2 G primary color signal.

The B primary color signal is taken into the image input section 32 to create G3 primary color image data.

Next, in step 5T14, the control unit 36 causes the GB primary color image data obtained by the image input unit 32 to be transferred to the image processing unit 33, and uses each of the windows 40-1 to 40-n indicated by the window information. The GB primary color images of each of the parts 28-1 to 28-n are cut out from the GB primary color image data, and the color images of the parts are extracted.

After this, the control unit 36 controls the image processing unit 3 in step 5T15.
3, the B primary color signal is subtracted from the G primary color signal constituting the color component image to create a G-B subtracted n video signal.

Next, the control unit 36 instructs the image processing unit 33 in step S T 16 to determine the colors of the parts 28-1 to 28-n in the GB reduction bidet 'A' and the color of the base substrate 27. At the same time, the characteristic parameters (parameters to be inspected) of these parts 28-1 to 28-n are extracted based on the processing procedure and the type of each characteristic parameter.
5 and compared with the reference parameters.

Then, based on this comparison result, the determination unit 35 determines that the part 28-1
-28-n are all present and whether any positional deviations have occurred, and the check results are supplied to the judgment result output section 18, where they are displayed or printed out.

In this way, in this embodiment, two monochrome TVs
Cameras 42 and 43 are used, but these monochrome TVs
Instead of the cameras 42 and 43, as shown in FIG. 1 (also, the printed circuit board 25-2 to be inspected) may be imaged in-line while traveling.

In this way, the resolution can be varied by intermittent driving of the pulse motor 49 of the belt conveyor section 46 by the conveyor controller 718, and the resolution can be varied by using the monochrome TV camera 42°/13. [
You can cover yourself cheaply.

Further, in each of the embodiments described above, the G-B subtraction video signal is created by digital processing, but the G-8 subtraction video signal may be created by analog processing.

Further, in the above-described embodiment, data regarding the tuna and shape of the parts 28-1 to 28-n are inputted from the information input section 19, but these data are inputted when the base board is black and the part 28-n. 1 to 28-n may be input by using a monochrome TV camera 42.431C as an image of a teaching board painted white.

Furthermore, in the embodiment described above, the feature parameters are directly extracted from the reference printed circuit board 25-1 during teaching, but the bare board before the components 28-1 to 28-n are mounted and these Parts 28-1 to 28
- Each G- obtained by making a monochrome TV camera 42.43 a Wi image of the reference printed circuit board 25-1 on which 〇 is mounted.
While comparing the subtracted video signals of 8, each component 28-1~
28-n may be found and extracted.

In this case, the indexing process for each feature parameter may be performed in a hierarchical structure so that effective feature parameters can be quickly and efficiently found for each of the parts 28-1 to 28-n.

Further, in the above-mentioned embodiment, the color of the base substrate 27 is yellow, but when a fluorescent agent is added to the preflux, solder cream, etc. applied to the base substrate 27,
The color of the light emitted by this fluorescent agent and each part 28-1 to 28-
Since it is sufficient to be able to distinguish between the color of n and the color of n, in this case, the color of the base substrate 27 may be different.

Further, in the above embodiment, the base substrate 27 is yellow in color, but the components 28-1 to 28-n may be yellow.

A similar effect can also be obtained by using green instead of yellow.

(Effects of the Invention) As explained above, according to the present invention, an expensive color TV
A color image of the substrate can be obtained without using a camera, thereby reducing the cost of the device itself.

[Brief explanation of drawings]

Figure 1 shows an example of the component mounting board inspection device according to the present invention.
FIG. 2 is a block diagram showing an example, and FIG.
Figure (A) is a flowchart showing an example of a teaching operation in this embodiment, Figure 3 (B) is a flowchart showing an example of an inspection operation in this embodiment, and Figure 4 is a schematic diagram showing an example of a window used in this embodiment. 5 is a block diagram showing another embodiment of the component mounting board inspection device according to the present invention,
FIG. 6 is a schematic diagram of the Munsell color wheel used to explain the conventional component detection principle, and FIG. 7 is an X-Y chromaticity diagram used to explain the component detection principle of this embodiment. 8th
The figure is a block diagram showing an example of a conventional automatic inspection 5AIff. 16... Imaging unit, 17... Processing unit, 25-1...
Reference board (reference printed board), 25-2... Board to be inspected (printed board to be inspected), 27... Raw V board, 28
-1 to 28-n... parts. y= kx Procedural correction teeth March 9, 1982

Claims (1)

[Claims] A component mounting board inspection device that inspects components on the board by performing a comparison operation between multiple color images obtained by imaging a board on which components are mounted, the imaging unit for imaging the board; A component mounting board inspection device characterized by being provided with a plurality of imaging devices that take images of different colors.