JPS62261050A - Printed circuit board inspecting device - Google Patents

Abstract

PURPOSE:To automatically performing a selection of an optimum feature parameter for checking the mounted state of a part and a decision on a criterion reference data, by preparing the judging reference data based on a distribution of features of part images and base circuit boards. CONSTITUTION:An inspecting device is made up of an X-Y table section 14 having pins 20a and 20b for positioning a base circuit board 9 and printed circuit boards 10-1 and 10-2, a photography section 15 having a color TV camera 21, a teaching table 15, an image processing section 26, a keyboard 30 and the like and a processing section 16 having a CPU31 for controlling them. The CPU31 extracts a plurality of part mounted area image data and a plurality of part image data separately from image data obtained by photographing 15 is plurality of base circuit boards 9 and the reference printed circuit board 10-1 using a window (for taking in data) while automatically determining the type of feature parameter used and the value of a criterion reference data from a color distribution of these part mounted area image data and part image data to inspect the printed circuit board 10-2 to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides a WI
The present invention relates to a printed circuit board inspection apparatus for inspecting the presence or absence of components on the printed circuit board to be inspected, positional deviation, etc. by alpha-embedding an image obtained by imaging.

(Prior Art) When an automatic mounting device is used to mount various deep parts such as resistors and semiconductor elements on a printed circuit board, the parts may not be mounted according to the mount data after mounting.

Therefore, when using such an automatic mounting device, check the printed circuit board 1 after mounting to ensure that the correct chip components are in the correct position on the printed circuit board F in the correct orientation (position (6, direction)). It is necessary to check whether it is mounted and whether it has fallen off.

However, such inspections must be done manually as in the past.
] There is a problem in that if the inspection is done correctly by visual inspection, it is not possible to completely eliminate the occurrence of inspection errors, and it is not possible to increase the inspection speed.

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

FIG. 11 is a block diagram showing an example of such an automatic inspection device.

The automatic inspection device shown in this figure compares reference data inputted in advance with inspection data obtained by imaging the printed circuit board 1 to be inspected, and detects all the parts 2 on the printed circuit board 1 to be inspected. -1 to 2-n are placed on the keyboard 3, and whether or not these parts 2-1 to 2-n have changed in price. The storage section 4, TV camera 5, processing section 6, and display section 7 are leaked.

The keyboard 3 is equipped with various keys such as a function key and a numeric keypad, and is used to store reference data when the printed circuit board 1 to be inspected is inspected by an operator, that is, type data of the printed circuit board 1 to be inspected, and this printed Color data of parts 2-1 to 2-n that should be on board 1, installation 'E1. M data, mounting is performed based on each characteristic data such as posture data and shape data, and each component 2-1 to 2-1 on the printed circuit board 1 to be inspected based on these characteristic data.
When judgment standard data and the like necessary for inspecting the quality of 2-n are input, each of these data is supplied to the storage section 4 as standard data.

The storage section 4 includes a RAM (Random Access Memory), etc., and stores the reference data supplied from the keyboard 3, and also supplies this to the processing section 6.

The processing unit 6 processes the image of the printed circuit board 1 to be inspected obtained by the TV camera 5, and obtains each characteristic data ( At the same time, the data to be inspected is extracted based on the reference data stored in the storage section 4, and the data to be inspected is supplied to the display section 7 to display each part 2-1. ~2-n displays the quality.

(Problems to be Solved by the Invention) By the way, in such conventional automatic inspection equipment, an operator can use image data obtained by capturing a reference printed circuit board, which is a reference when inspecting the printed circuit board 1 to be inspected. The types of characteristic parameters of each part 2-1 to 2-n were determined, judgment standard data was created, and this information was inputted from the keyboard 3.

However, in this case, there is no clear method to solve the problem of which type of characteristic parameter is most effective for which part, or what judgment standard value should be set at that time. Unless the operator has the knowledge, selection and judgment of these feature parameters J! It was not possible to determine quasi-data. Further, even such an operator can only select characteristic parameters and determine criterion data by trial and error, and therefore, there is a problem in that the task takes too much time.

In view of the above-mentioned circumstances, the present invention automatically selects characteristic parameters that are optimal for checking the mounting state of components from image data obtained by capturing multiple images of a bare board and a printed circuit board, respectively. The present invention aims to provide a printed circuit board inspection equipment that can automatically determine judgment reference data.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the printed board inspection equipment 4 according to the present invention inspects the printed board to be inspected based on the judgment standard data stored in the storage section. In the printed circuit board inspection system (2), which inspects images obtained by visualization and inspects the mounting state of the components of the printed circuit board to be inspected, an RR that images a plurality of reference printed circuit boards and a plurality of base boards, respectively. 1 by this transportation department! an image cutting unit that cuts out each component image and each elementary board image in the component placement area portion from each reference printed circuit board image and each elementary V board image, respectively;
What are the characteristics of each component image extracted by this image extraction unit and the characteristics of each base board image? Ifi
It is characterized by the fact that

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a printed circuit board inspection apparatus according to the present invention.

The printed circuit board inspection apparatus shown in this figure includes an X-Y table section 14, an R image 81115, and a processing section 16, and includes a plurality of (for example, six) bare substrates 9 and a plurality of (for example, six) bare substrates 9.
For example, a plurality of component mounting area image data and a plurality of component image data are generated using a window (data import window) from each image data obtained by imaging the reference printed circuit boards 10-1 (for example, 6 pieces). In addition to extracting each of
Based on the color distribution of each component mounting area image data and each component image data, the type of feature parameter to be used and the value of the criterion data are automatically determined, and the printed curtain board 10-2 to be inspected is determined. inspect.

The X-Y table section 14 includes a pulse motor 17.18 that operates based on a control signal from the processing section 16, and an X-Y table that is driven in the X-axis direction and the Y-axis direction by each of these pulse motors 17.18. 19 and pins 20a and 2ob for positioning the printed circuit board provided on the X-Y table 19. When placing the substrates, the substrates 9 to 10-2 are positioned by fitting the positioning holes formed in the substrates 9 to 10-2 into the respective bins 20a and 20b.

The imaging section 15 includes a color TV camera 21 provided above the X-Y table section 14, and a ring illumination device 22 provided on the front side of the lens of the color TV camera 21. 10-2 is illuminated by this ring illumination device 22 and imaged by the color TV camera 21, and by this imaging operation, 1 town 1
The resulting image quality signal is supplied to the processing section 16.

! l! lI! The 11 part 16 determines the type of feature parameter used in the inspection based on the color distribution of the plurality of blank board image signals supplied from the Wi image part 15 and the plurality of reference printed circuit board image signals, After determining the judgment standard data, the selected type of characteristic parameters are extracted from the inspected printed circuit board image signal supplied from the imaging section 15, and the extraction results are compared with the judgment standard data. By doing so, it is possible to check whether all the components 13b are present on the printed circuit board 10-2 to be inspected and these components 13.
b is a part that determines whether a positional shift or the like has occurred, and includes an A/D conversion section 23, a memory 24, a teaching table 25, an image processing section 26, an X-Y stage controller 27, It includes a CRT display 28, a printer 29, a keyboard 30, and a control unit (CPU) 31.

When the A/D conversion section 23 is supplied with an image signal from the imaging section 15, it performs A/D conversion (analog-to-digital conversion) to create image data, and supplies this to the control section 31.

Further, the memory 24 includes a RAM (Random Access Memory) and the like.

It is used as a work area for the control section 31.

Furthermore, the brass processing section 26 is configured to binarize the image data using this open chain when it is supplied with the image data and the image data v1 from the control section 31, and the two WE conversion results ( 21 image data) is supplied to the control section 31.

Further, the teaching table 25 is equipped with a floppy disk device, etc., and when it is supplied with a data file etc. from the control unit 31, it stores it and also stores the data file etc.
When the 1160 unit 31 outputs a transfer request, it reads the data file etc. in response to this request and sends it to the control unit 3.
1 etc.

Further, the X-Y stage controller 27 is configured to include an interface for connecting the il+Obejinto and the X-Yi-pull section 14, and is configured to perform the control based on the output of the control section 31. Controls the X-Y table section 14.

Further, the CRT display 28 is connected to a cathode ray tube (CRT) and displays image data from the control unit 11 31.

As a result of the determination, 'F--When the human scale data is supplied, this is displayed on the screen.

Further, the printer 294 receives the judgment result from the Jil control section 31 and prints it out in a predetermined format (A-mat).

Further, the keyboard 30 is used to store operation information, data regarding the reference printed circuit board 10-1, and the like.
The keyboard 30 is equipped with various keys necessary for inputting data, etc. regarding the component 13a on the keyboard 30, and information, data, etc. input from the keyboard 30 are supplied to the control section 31.

The tllll 10 unit 31 includes a microprocessor and the like, and controls the A/D converter 23 to the keyboard 30 and processes various data based on a program input in advance.

Next, the operation of this embodiment will be explained with reference to the flowcharts shown in FIGS. 2 and 3.

First, when inspecting a new printed circuit board 10-2 to be inspected, the control section 31 initializes each circuit section in step ST1 of the flowchart (not shown in FIG. 2) to put them into a teaching mode, and then in step ST2. Window creation processing is performed to create a component placement area 32-4 as shown in FIG.
Create a window 37 located in the corner. In this case, each window 37 is created for each component that is counterstained for inspection.

Next, in step ST3, the control section 31 checks whether or not the first bare substrate 9 is set on the X-Y table section 14, and if it is set, the X-Y
The table section 14 is moved ll1jt11 to cause the imaging section 15 to take an image of the base substrate 9, and as a result, the base board 9 is captured by 1q! The A/r converter 23 converts the board image signal into bare board image data.

In this 11/, the control unit 31 uses each window 37 created for each component in step ST4 to
- Cut out the image data of the four corners of the part placement area 32) where each part is mounted from the beginning.

Next, in step ST5, the control unit 31 extracts a plurality of predetermined parameters from the R (red) color data, G (green) color data, and B (red) color data constituting each of the four corner image data. is extracted, and in step ST6 this is set as the parameter P
A parameter table 35 as shown in FIG. 5 is created as a11 to Pamn.

In this case, the first to nth parameters may be a combination of the brightness of the 8 color data and the brightness of the 0 color data, or
Each brightness of color data, 0 color data, 8 color data (or
R/G data, B/
A combination of G data, R/(R-)-G+8) data, etc. is used.

After that, the control unit 31 checks whether the above-mentioned processing has been completed for the six raw substrates 9 in step ST7, and if there remains υ1 area that has not been processed yet, from this step ST7 to the above-mentioned processing. Returning to step ST3, the above-described process is performed on the remaining bare substrates 9.

Then, when the parameter extraction process is completed for all six raw substrates 9, the control section 31 performs step ST7.
The process branches to step ST8, where the parameters Pa11 to Pfmn of each of the bare substrates 9 are classified based on each window and each parameter type, and a table 36 as shown in FIG. 6 is created. After that, the control unit 31 controls each base board 9 regarding the first window and the first parameter.
Parameters Pa11, Pb11, Pc11, Pd11
, Pc11. Existence area E a 4- when Pfl is plotted on the plane corresponding to the type of parameter (1)
Add +1.

In this case, for the plane, this first parameter is! When it is a combination of the brightness of the data and the brightness of the Ge data, a plane is used whose horizontal axis is the brightness of 0 color and whose vertical axis is the brightness of the color. When it is a combination of data, as in the case of the parameters described above, a plane is used in which one of the combined data is the horizontal axis and the other is the vertical axis.

The distribution at this time is, if the first parameters Pa11 to Pf11 of each prime number 9 for this first window do not vary, as shown in FIG. b・t E a
becomes smaller, and each of these parameters r) a 11
- If Pfll varies, its existence 1iitEa increases as shown in FIG. 7(B).

Thereafter, the control unit 31 repeats the above-described process by changing the parameter type and window number, and calculates the parameter existence 14[Ea of each base board 9 regarding each window and each parameter type.

Next, the it, II 00 section 31 determines whether the sixth base board 9 from the X-Y table section 14 has been removed and the first reference printed circuit board 10-1 has been set in its place in step ST9. If this is set, the X-Y table section 14 is controlled and the 'fi image section 1
5 to image the reference printed circuit board 10-1,
The reference printed circuit board image signal obtained by this is
It is converted into reference printed circuit board image data by D conversion ff123.

Thereafter, in step 5TIO, the control unit 31 uses each window 37 to cut out four corner image data of each component 13a from the base board image data.

Next, in step 5T11, the control unit 31 extracts a plurality of predetermined parameters from the R color data, 0 color data, and 8 color data constituting each of the four corner image data,
In step 5T12, send this to rose make P'all -p
A parameter table as described above is created as -f'mn. In this case, the same type of parameters as those used for the base substrate 9 are used.

After this, the control unit 31 controls the six l
1. It is checked whether the above-mentioned processing has been completed for the printed circuit board 10-1, and if there remains a standard printed circuit board 10-1 that has not been processed yet, the process returns from step 5T13 to step ST9 and the remaining The above-described process is performed on the reference printed circuit board 10-1 at t7.

Then, when the parameter extraction processing for all six jul printed bases 110-1 is completed, the control unit 31
The process branches from step 5T13 to step 5T14, where the existence range of each parameter P=al 1 to Pfmn of each reference printed circuit board 10-1 is calculated for each window number and parameter type.

In this case, the parameters Pa11 to p r of the base substrate 9
Similarly to mn, the parameters of each reference printed circuit board 10-1 for one window, for example, the parameter P=a
11 to P-f11 do not vary, each of these parameters P-a11 to P-f11 as shown in FIG. 8(A).
The existence range Eb becomes small, and if each of these parameters P' = a 11~P'fil varies,
As shown in FIG. 8(B), the existence MEb becomes large.

Next, the control unit 31 selects the first window in step ST15, and controls each of the base substrates 9 for this window.
The existence of the first parameter ti! It is checked whether Ea and the first parameter existence [Eb of each reference printed circuit board 10-1] overlap, and if they overlap as shown in FIG. The next parameter (in this case, the second parameter) is sequentially selected, and each parameter existence range Ea for this parameter is determined.

It is sequentially checked whether Eb overlaps or not.

Then, as shown in FIG. 9(B), if a parameter is found that is not configured in each of the parameter tables Ea and Fb, the process branches from step 5T15 to step 5T16.

Soshite, axltlDffi31 C, standard print 1. with this step 5T16. After setting the judgment ItW value area 33 so as to surround the parameter location [b on the board 10-1 side, the data regarding this judgment standard area 33 and the parameter type at this time are also stored in the each team 25. Then, proceed to step 5T18.

In this case, the judgment base 1%j value]-Ria 33 visualizes the substrate 10-2 (printer to be inspected) and displays the first window 37 from the processed image data. The four corner image data cut out using the four-corner image data are used as Ts7 to determine whether the image data of each of the four corners is the corner data of the component 13b, or whether the component 13 is the bare board image data of the component to be mounted 1.

Further, in step 5T15, for all types of parameters, as shown in FIG. 9 (Δ), the parameter existence 1aEa on the bare board 9 side and the parameter existence area Eb on the reference printed circuit board 10-1 side overlap. If it is determined, the control section 31 branches from this step 5T15 to step ST17, and here displays the message on the CRT display P128, prints out the message from the printer 29, and displays the message in this first window. The operator is informed that the Tli constant JJQj area 33 could not be set for 37.

When the above-described processing is completed for all windows, the control unit 31 ends this teaching operation.

Further, when inspecting the test board 10-2 that is mass-produced to be the same as the reference printed circuit board 10-1, the control section 31 first initializes each part of the circuit in step 5T20 of the inspection flowchart shown in FIG. , put them in inspection mode.

Thereafter, the printed circuit board 10-2 to be inspected is set on the X-Y table section 14 by an operator or the like.
In step 5T21, the control section 331 controls the FX-Y table section 14 to cause the image carrying section 15 to carry the printed circuit board 10-2 to be inspected, and at this time, i! The Δ/D converter 23 converts the image signal into image data (printed board image data to be inspected).

Next, in step 5T22, the control unit 31 uses each window 37 to cut out four corner image data of one rear on which each component 13b is mounted from the image data of the printed circuit board to be inspected.

Next, in step 5T23, the control unit 31 selects 8 color data, 0 color data, and 1 color data constituting the four corner image display data.
Extract the types of parameters determined at the time of processing from the three color data and use them as parameters PC1 to PCF'
After memorizing it as cm, select part 1 with Me 1 Tsubu 5T24.
Whether each parameter Pc1 to pcm for each 3b is inside or outside each judgment criterion area 33 (the rear 33 is set for each window) stored in the teaching meeple 25. Determine each.

After that, the control unit 31 controls the first part 1 in step 5T25.
It is checked whether all of the parameters Pc1 to Pc4 of 3b are within each determination reference area 33, and if all of these parameters PC1 to Pc4 are within each determination MQ' area 33, the steps from step 5T25 are performed. 5T26, where all the windows 37 for this part 13b are shown in part 13 as shown in FIG.
It is determined that the body 13b (or electric l4i) is detected, that is, the component 13b is mounted without any positional deviation, and that the component 13 is correctly mounted on the CR7 display 28. After displaying a message indicating this, the process advances from step 5T26 to step 5T30.

Further, in step 5T25, if it is determined that any one of all parameters PC1 to Pc4 of the component 13b is not within each determination reference area 33, the control section 31 branches from step 5T25 to step 5T27, Here, each parameter Pcl to Pc4 of this part 13b
If any one of the parameters PCI to Pc4 is within the judgment criterion area 33, step 5T27 is executed. 5T28, where one of the windows 37 is detecting the body (or electrode) of the component 13b as shown in FIG. 10(B), that is, the component 13b is misaligned. After determining that this is the case and displaying a message on the CRT display 28 that does not indicate that the component 13b is misaligned, the process advances from step 5T28 to step 5T30.

Further, in the step 5T27, if all the parameters Pc1 to PC4 of the component 13b are not within each criterion area 33, the control section 31 branches from this step 5T27 to the suit part S T 29, and here
1j, each window 37 is not detecting the bore (or electrode) of the component 13, that is, it is determined that the component that should be in this area has fallen off, and CR
After displaying a message indicating that this part has fallen off on the 1 display 28, the process advances from step 5T29 to step 5T30.

Then, in step 5T30, the control unit 31 checks whether or not the dropout and positional deviation determination process has been completed for all the components 13b of the printed circuit board 10-2 to be inspected.
If there are still unprocessed parts 13b, the process returns from step 5T30 to step 5T25,
The above-described process is executed for the remaining parts 13b.

All parts 13 of this printed circuit board 10-2 to be inspected
When the process for test b is completed, the control unit 31 displays the quality of the printed circuit board 10-2 to be inspected on the CRT display 28, and then ends this inspection flowchart.

As described above, in this embodiment, the parameters Pa11 to p of the raw substrate 1iIlj images extracted from the plurality of raw substrates 9 are
Judgment reference area 3 for each window 37 is determined from the distribution state of fmn and parameters l"all to P-rmn of component images extracted from a plurality of reference printed circuit boards 10-1.
Since we are looking for 3, even if an operator with less specialized knowledge operates, the judgment will always be optimal J! quasi-data can be obtained.

In addition, in the above embodiment, during deeding,
Using a plane, each parameter Pa1l~Pfmn, p
-a 11~P -f mn(7) Distribution: tt3Lr
However, it is better to measure the distribution of each parameter using a multidimensional space that combines these multiple types of parameters.

Further, in the embodiment described above, the windows 37 are provided near the four corners of one component, but as shown in FIG.
It would be good to have a .

In addition, in the two consecutive embodiments, the determination reference area 33 is obtained for each window 37, but these windows 37 are handled collectively for each component or each board, and each window 37 is handled for each component (or each board).

The determination 1FtPx rear that is common to the substrate angle) may be obtained.

Further, in the embodiment described above, the distribution of the parameters Pa11 to Pfmn of the plurality of base substrates 9 and the reference parameter P
The determination reference area 33 is determined based on the overlap with the distribution of -a11 to p-'rmn, but the parameters for one window, for example, the parameter pa
11 to Pf'11 and parameter P=a11 to P-f1
1 and vice versa to obtain a judgment value, and the probability N when a judgment is made using this judgment value may be obtained. In this case, let the median value of the distribution function f1 for one parameter Pa11 to Pf'11 be Mm, and the standard deviation 1tfJ be σm, and the median fraction of the distribution 1311 number f2 for pr'11 to the other parameter P=811 be Mj , standard @ difference value aj
Then, the above judgment value and the certainty N are respectively L=Mm+ (Mj-Mn)Xσm/ (σm+cyj
)・・・・・・(1) N= (Mj−Mm)/(σm−+ aj)−−−(
2) Given by. In this case, the control unit 31 displays I+i of this certainty N on the CR1 display 28, and selects parameters such that Vl of this certainty N is equal to or greater than a certain value. As shown in A), the distribution function f1 regarding one of the parameters Pa11 to Pfll
If the distribution function f2 regarding the other parameters P'a11 to p=rii is far apart, it is determined that this parameter is suitable for this window, and this parameter is used. #ru.

Moreover, as shown in FIG. 12(B), the distribution function f1 regarding one parameter [)a11 to Pf11 and the distribution function f1 regarding the other parameter P'a11 to P'f11 '
2 partially overlaps, the control unit 31 selects this window, determines that this parameter is not suitable, and selects another parameter.

(Effects of the Invention) As explained above, according to the present invention, it is possible to visualize the mounting state of components from the image data obtained by visualizing a plurality of bare boards and 11 base QI printed boards. It is possible to self-help select the optimal characteristic parameters for J-ro, and automatically create judgment standard data.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a printed circuit board inspection device according to the present invention, FIG. 2 is a flowchart showing an example of the teaching operation of the embodiment, and FIG. 3 is a flowchart showing an example of the inspection operation of the embodiment. FIG. 4 is a schematic diagram showing an example of a window used in the same embodiment. FIG. 5 is a polar diagram showing an example of a parameter table used in the same embodiment, FIG. 6 is a schematic diagram showing an example of a table used during parameter processing used in the same embodiment, and FIG. 7 (A),
(R) is a schematic diagram showing an example of the distribution of basic printed circuit board parameters in the same example, and FIGS. Figures 9 (A) and (B) are schematic diagrams showing examples of the distribution of bare board parameters and reference printed circuit board parameters in the same example, and Figures 10A to (C) are diagrams showing parts in the same example, respectively. Schematic diagram showing an example of mounting, No. 11
The figure is a schematic diagram showing another example of the window used in the present invention, and FIGS. FIG. 13 is a block diagram showing an example of a conventional automatic inspection device. 9... Cable J, board, 10-1... 4 reference prints, 10-2... Printed circuit board to be inspected, 15... Imaging section, 25... Storage section (teaching meeple) , 31
...Image cropping section, judgment standard data creation section (control section)
. Patent applicant: Tateishi Electric Co., Ltd.
Patent Attorney 1 Seen 0 Tetsuji (Haku 1) Trap 3z Jun Junichi IL 3ri P=====-Go,? 7 Sani Mouth! 1y,” 318-ro hi〉37 X7$tA) %7ko(it)
Tsuta 80 (A) Tip 8171 (S
) Calculation 5 index 6I? 1 East CI order ^) Book QijBB> also 1
1θ

Claims (1)

[Claims] Based on the judgment criteria data stored in the storage unit,
In a printed circuit board inspection apparatus that inspects images obtained by imaging a printed circuit board to be inspected to inspect the mounting state of components of the printed circuit board to be inspected, a plurality of images of each of a reference printed circuit board and a plurality of base boards are imaged. an image capturing unit that cuts out each component image and each bare board image in the component placement area from each reference printed circuit board image and each bare board image obtained by the imaging unit; 1. A printed circuit board inspection apparatus comprising: a determination criterion data creation section that creates determination criterion data based on the distribution of features of each component image and features of each bare board image obtained by the section.