JPS62261049A - Printed circuit board inspecting device - Google Patents

Abstract

PURPOSE:To enable automatic selection of optimum feature parameters and automatic generation of a criterion reference data, by preparing the criterion reference data based on the distribution of features of part images and those of base circuit board images. CONSTITUTION:An inspecting device is made up of an X-Y table 14 having pins 20a and 20b for positioning printed circuit boards, a photography section 15 having a color TV camera 21 and a processing section 16 which has a teaching table 25, an image processing section 26, a keyboard 30 and the like, all controlled by a CPU31. The CPU31 extracts a part mounted area image data and a part image data separately from an image data as obtained by photographing 15 a base circuit board 9 and a reference printed circuit board 10-1 using a window (for taking in data) while automatically determining the type of a 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. Then, a printed circuit board 10-2 to be inspected is inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention conveys an image of a printed circuit board to be inspected on which components are mounted (processing the image to be inspected),
We are involved in printed circuit board inspection equipment that inspects the presence or absence of components on boards, as well as head misalignment, etc.

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

For this reason, when using such an automatic mounting device, the printed circuit board is checked on each mount to ensure that the correct chip components are in the correct position on the printed board and in the correct orientation. ) and whether it is mounted or not and whether it has fallen off.

However, such inspections must be done manually as in the past.
If this was done during the 1st holiday inspection, there would have been an inspection error! 1 cannot be completely eliminated, and the inspection speed cannot be increased.

Therefore, in recent years, various manufacturers have proposed 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 is pre-filled! The quasi-data is compared with the inspected data obtained by imaging the printed circuit board 1 to be inspected to determine whether all the components 2-1 to 2-n are placed on the printed circuit board 1 to be inspected; These parts 2-1 to 2-n are automatically inspected to see if they have misaligned, etc., and the keyboard 3, storage unit 4, TV camera 5, processing unit 6, , and a display section 7.

The keyboard 3 is equipped with various keys such as a function key and a numeric keypad, and provides reference data when the printed circuit board 1 to be inspected is inspected by an operator or the like, that is, type data of the printed circuit board 1 to be inspected, and this printed circuit board to be inspected. 1, each feature data such as color data, mounting position data, mounting posture data, shape data, etc. of the parts 2-1 to 2-n on the board 1, and the printed circuit board to be inspected based on each of these feature data. Each part 2-1 to 2-n on 1
When the judgment standard data necessary for inspecting the quality of the data is input, each of these data is supplied to the storage section 4 as the standard data.

The storage section 4 is equipped with a RAM (random access memory), etc., and supplies the reference data supplied from the keyboard 3 to the processing section 6 together with the storage section.

The processing unit 6 processes the image of the printed circuit board 1 to be inspected obtained by the TV camera 5, and determines the characteristics of each component 2-1 to 2-n mounted on the printed circuit board 1 to be inspected. At the same time as extracting the data (data to be inspected), this data to be inspected is checked based on the reference data stored in the storage section 4, and the check result is supplied to the display section 7 to display the data for each of the parts. The quality of 2-1 to 2-n is displayed.

(Problems to be Solved by the Invention) However, in such a conventional automatic inspection device, an operator performs various operations based on image data obtained by imaging a reference printed circuit board that serves as a reference for inspecting the printed circuit board 1 to be inspected. Characteristic parameters and judgment criteria data for the parts 2-1 to 2-n were created and inputted from the keyboard 3.

However, in this case, there is no clear method to solve the problem of which feature parameters are most effective for which parts, and what criteria values should be set at that time, so If you are not an operator,
It was not possible to determine the types of feature parameters or the values of criteria data, etc. In addition, even such an operator can only determine the type of characteristic parameter, the value of the criterion data, etc. by trial and error, so there is a problem in that it takes too much time to create them.

In view of the above-mentioned circumstances, the present invention automatically selects the optimum characteristic parameters for checking the mounted state of parts from the image data obtained by transporting the printed circuit board, and automatically selects the judgment standard data. Our first objective is to provide a printed circuit board inspection device that can be used to

(Means for Solving the Problems) In order to solve the above problems, the printed circuit board inspection apparatus according to the present invention provides the determination I! In a printed circuit board inspection apparatus that takes an image of a printed circuit board to be inspected based on semi-data and inspects the captured image, the printed circuit board to be inspected 1-r is inspected for the mounting state of components on the board. and an imaging section that images the substrate and the bare board, and from the IJ quasi-printed circuit board image and the bare board image obtained by this imaging section, a component image and a component placement area?
1. An image cutting section that cuts out the number of windows of 'Fi necessary to cut out one board image, and the distribution of the features of each component image and the features of each base board image obtained by I+7 by this image cutting section. Judgment that creates judgment standard data based on t! ,! If data creation section.

(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, a decoy image section 15, and a processing section 16.
1 by taking images of the base board 9 and the reference printed circuit board 10-1.
Component mount area image data and component image data are each extracted from each image data obtained using a window (data import window), and from the color distribution of these component mount area image data and component image data, The type of V1yi parameter to be used and the value of the judgment standard data are automatically determined, and the board 1 is transferred to the print to be inspected.
Inspect 0-2.

The X-Y table unit 14 includes a pulse motor 17° 18 that operates based on a control signal from the processing unit 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 and 18. and a bin 208.20b for positioning the printed circuit board provided on the X-Y table 19. When mounting, each of these boards 9 to 10-2 is positioned in one position by inserting each of the pins 20a and 20b into positioning holes formed in each of these boards 9 to 10-2. Ru.

The R image 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 are imaged by the color TV camera 21 while being illuminated by the ring illumination device 22, and an image signal increased by +1 by this imaging operation is supplied to the processing section 16.

The processing unit 16 receives the element Itff supplied from the imaging unit 15.
After determining the type of characteristic parameter to be used in the inspection and the value of the judgment reference data based on the color distribution of the iiihi image signal and the reference printed circuit board image signal, the 1) Extract characteristic parameters from the printed circuit board image signal and compare the extraction results with judgment standard data to determine the printed circuit board 10 to be inspected.
This is a part that determines whether all the parts 13b are on the -2 and whether or not these parts 13b are misaligned.
4, a teaching table 25, an image processing section 26, an X-Y stage controller 27, and a CRT display 2.
8, a printer 29, a keyboard 30, and a control unit (C
PLI) 31.

When the Δ/D conversion unit 23 receives the image signal from the imaging unit 15, it converts it into A10'I! (analog-to-digital conversion) to create image data, and convert this into fil+
'60 Supply to Department 31.

Further, the memory 24 includes a RAM (random access memory, etc., and the control) M
It is used as a work area for 31 people.

Further, the image processing section 26 is configured to, when supplied with image data and a threshold value via the control section 31, binarize the image data using the threshold value, and this binarization result ( 21i!'l image data) is supplied to the υ control section 31.

Furthermore, the teaching table 25 is equipped with a floppy disk device, etc., and stores the data file etc. when it is supplied from the control section 31, and when the control section 31 outputs a transfer request. It reads out data files and the like in response to requests and supplies them to the control unit 31 and the like.

Further, the X-Y stage controller 27 is connected to the control section 31.
and the X-Y table section 14, and includes an interface, etc., for connecting the
+'l' To the output of III section 31: is light T
The XY table section 14 is controlled.

The CR7 display 28 also has a cathode ray tube (CRT) and receives image data from the control section 31.

When you are provided with judgment results, main/manpower data, etc., display them on both sides.

Further, when the blink 29 is supplied with the determination result etc. from the front controller 31, the blink 29 performs a predetermined internal function (phonet) 1~out.

Furthermore, -1-- the board 30 is equipped with various keys necessary for inputting data related to the reference printed circuit board 10-1, data related to the component 13a on this reference printed circuit board 10-1, etc. and this keyboard 3
Information, data, etc. input from 0 are supplied to the control section 31.

The control unit 31 includes a micro-brochure, etc.
It 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 70-diameter 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 chart 70 shown in FIG. The creation process is performed, and windows 378 to 37d located at the four corners of the component placement area 32 are created as shown in FIG. create.

In this case, each window 37a to 37d is created for each component to be inspected.

Next, in step ST3, the control section 31 checks whether the bare substrate 9 is set on the X-Y table FIS 14, and if it is set, controls the X-Y table section 14 to set the imaging section. 15, the first divided area of the bare substrate 9 is set to [1e], and the resulting bare board image signal is converted into i-board image data by the A/D converter 23.

Thereafter, the 1IIIn unit 31 uses the respective windows 37a to 37d created for each component in step ST4 to determine the area where the component to be inspected is mounted (component placement area 32) from the previous element board image data. Cut the four corner image data into parts and calculate the specific gravity.

Next, in step ST5, the control unit 31 converts 8 color data and 0 color data from R (red) color data, G (green) color data, and B (blue) color data constituting each of the four corner image data. This is extracted as a parameter pa, and is stored for each component placement area 32 in step ST6.

After this, the control unit 31 performs step ST7 on the bare substrate 9 of the lever.
It is checked whether the above-mentioned processing has been completed for all divided areas, and if there are still unprocessed divided areas, the steps from step ST7 to step S are performed.
Returning to T3, the above-described process is executed for the remaining divided areas.

Then, when the parameter extraction process is completed for all divided areas of the base substrate 9, the control section 31 performs the step ST.
7 branches to step S-'8, where the raw substrate 9
The existence range when each parameter pa of is plotted on the RG plane is calculated for each part.

In this case, if the R color brightness and G color density of each parameter are similar, the existence range Ea of each parameter pa will be small as shown in FIG. 5(A), and each parameter pa will be If they are not similar, the existence area Fa becomes larger as shown in FIG. 5(B).

Next, the control section 31 checks whether the base board 9 has been removed from the X-Y table section 14 and the 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 so that the first divided area of the reference printed circuit board 10-1 is made into an R image by the imaging section 15, and the reference printed circuit board image signal obtained thereby is converted into reference printed circuit board image data by the A/D conversion section 23. .

Thereafter, the controller 31 cuts out four corner image data of each component 13a from the base board image data using each of the windows 37a to 37d in step 5TIO.

Next, the control unit 31 performs step 5T11'r - 8 color data, 0 color data, and 8 color data constituting each of the four corner image data.
8 color data and 0 color data are extracted from the color data, and in step 5T12, each part 1 is set using this as a parameter pb.
3ξ】10.

19, the control unit 31 checks in step 5T13 whether the above-described processing has been completed for all divided areas of this reference printed circuit board 10-1, and if there are any divided areas for which the processing has not yet been completed, , returns from step S r 13 to step ST 9 and executes the above-described process for the remaining divided areas.

Then, when the parameter extraction process is completed for all divided areas of the reference printed circuit board 10-1, i,llt
The ll section 31 performs the steps from step 5T13 to step 5T1.
4, where the range of existence of each parameter Pb of the reference printed circuit board 10-1 is calculated for each component.

In this case, if each parameter pb of this reference printed circuit board 10-1 is similar to the parameter pa of the base board 9, the existence range Eb of each parameter pb is as shown in FIG. 6(A). becomes small, and if these parameters pb are not similar, the existence range Eb becomes large as shown in FIG. 6(B).

Next, the control unit 31 selects one component in step 5T15, and determines each parameter existence range Eb for this component.
and the parameter existing range of the base substrate 9 [a, Ea, Eb
As shown in Figure 7 (A>), if each of these parameter existence ranges "a, l
:b do not overlap, the process branches from step 5T15 to step ST'16.

Then, in step 5T16, the control unit 31 selects the parameter location 1 of the reference printed circuit board 10-1! After setting the determination reference value area 33 so as to surround Eb and storing this in the taking table 25, the process proceeds to Stella 7ST18.

In this case, in the judgment reference value area 33, each of the four corner image data cut out using the windows 37a to 37d from the image data of the printed circuit board to be inspected obtained by IS of the printed circuit board to be inspected 110-2 is It is used as an area for determining whether it is image data or raw board image data of a component on which this component 13 is mounted.

In addition, in the city record step S15, as shown in FIG. 7(B), the parameter existence range Eb of the reference printed board 10-1,
If it is determined that the parameter existence t4Ea of the bare substrate 9 overlaps, the control section 31 branches from this step 5T15 to step STI 7, where the CRT display 28
A message is displayed on the screen or a message is printed out from the printer 29 to notify that the determination reference area 33 could not be set for this part, and the process then proceeds to step 5T18.

Then, in step 5T18, the control section 31 checks whether the above-described processing has been completed for all parts, and repeats steps 5T15 to 5T18 until the processing is completed for all parts. And when all the parts have been processed! , the IJ control section 31 ends this debending operation.

Further, when inspecting the test board 10-2 which is mass-produced in the same way as the reference printed circuit board 10-1, the control jl18I531 first initializes each circuit part in step 5T20 of the test flowchart shown in FIG. into inspection mode.

Thereafter, when the printed circuit board 10-2 to be inspected is set on the X-Y table section 14 by an operator or the like, the control section 31 controls the X-Y table section 14 in step 5T21 to set the printed circuit board 10-2 on the X-Y table section 15. Test pudding 1-group ff110
-2's 1st minute 1.11 area is image-combined, and the image signal thus Vl is converted into image data (pre-examination pudding 1-base image data) by the conversion unit 23. let

Next, in step 5T22, the control unit 31 uses the windows 37a to 37d numbered for each component to obtain four corner image data of the area where each component 13b is to be mounted from the image data of the printed circuit board to be inspected. Cut out.

Next, in step 5T23, the control unit 31*, 1, extracts data from the 1st color data, 0th color data, and 8th color data that make up the four corner image f-ta [with 5th color data and 0th color data as parameters pc] After this, in step 718-24, it is determined whether each parameter pc of the component 13 b IQ is inside or outside the determination reference area 33 stored in the teaching table 25 .

After this, the control unit 31 moves one part 13b to the speed IL! in step 5T25. Next, it is checked whether all the parameters Pc of this part 13b are within the judgment standard area 33, and if all these parameters pc are within the judgment standard area 33, the process branches from step 5T25 to step 26. , here, as shown in FIG. 8(A), all the windows 37a to 37d are part 13t) body (
or the state in which electric power II) is being detected, that is, component 13b.
is determined to be mounted without any displacement,
After displaying a message on the CR7 display 28 indicating that the component 13 is normally mounted, the process advances from step 5T26 to step 5T30.

Further, in step 5T25, one part 13b
If it is determined that any one of all the parameters Pc is not within the determination reference area 33, the control unit 31 $;L branches from this step 5T25 to the switch 5T27,
Here, any one of each parameter PC of this part 13b
If any one of the parameters Pc is within the criterion area 33, the process branches from this step ST27 to step 5T28, where FIG. As shown in B), one of the windows 37a to 37d is detecting the body (or '1flfi) of the component 13b.

In other words, the process moves from step 5128 to step 5730 in a scene in which it is determined that the component 13b is misaligned, and a message indicating that the component 13b is misaligned is displayed on the CRT display 28. move on.

Further, in step 5T27, one part 13b
If all parameters of are within the criterion area 33,
The control unit 31 performs steps 5T27 to 5T.
29, and here, as shown in FIG. 8(C), each window 37a to 37d is in a state where none of the bodies (or electrodes) of the component 13 is detected, that is, the component that should be in this part has fallen off. 711 and displays a message on the CRT display 28 indicating that this part has fallen off.
Proceed to 30.

Then, in this step 5T30, the control unit 31 checks whether the dropout and positional deviation determination processing has been completed for all parts 13b in this divided area, and if there are any parts that have not been processed yet, this step From 5T30, the process returns to step 5T25, and the above-described process is repeated for the remaining parts.

After that, when the above-described dropout and positional deviation determination process is completed for all parts 13b in this divided area, the v control unit 3
Step 1 branches from step 5T30 to step 5T31, where it is checked whether the above-mentioned processing has been completed for all divided areas of this printed circuit board 10-2 to be inspected, and b. If the area remains, from this step 5T31 to the step 5
Returning to T21, the above-described process is executed for the remaining divided areas.

When the processing of all divided areas of the printed circuit board 10-2 to be inspected is completed, the control unit 31 displays the quality of the printed circuit board 10-2 to be inspected on the CR7 display 28, and then displays the inspection flowchart. end.

As described above, in this embodiment, the MW board image parameters Pa extracted from the base substrate 9 and the reference print 1.1
Since the determination reference area 33 is determined from the distribution state of the component image extracted from the board 10-1 and the parameter Pb,
Optimal judgment criteria data can always be obtained even when operated by an operator without specialized knowledge.

Further, in the above-described embodiment, the brightness of the R color data and the brightness of the 0 color data of the image data cut out using each window 37a to 37 (1) are used as parameters, but the Re data, the 0 color data , brightness 1 of 13 color data
．． '2 (R/G arta, B/G data obtained by combining (Yo, saturation, hue), R/(R→G + 13)
) data etc. may be used. In this case, each parameter is layered, and if the criterion area cannot be extracted with the first parameter, the parameter types are sequentially changed to find the optimal parameter for each part.Also, if these multiple types of parameters are combined The distribution of each parameter may be calculated in a multidimensional space.

Further, in the above embodiment, the determination reference area 33 is determined from the parameter pa of the base board 9 and the parameter pb of the reference printed circuit board 10-1, but as shown in FIG. Distribution center P1 of each parameter pa and each parameter p of the reference printed circuit board 10-1
b and the distribution center P2 of each window 37a to 37 is determined.
The parameter pc of the printed circuit board 10-2 to be inspected cut out using d, and the distribution center P of each parameter Pa, PB.
1, find the distances L1 and L2 from P2, and calculate each of these nodes 1i
It may be determined that the body (or electrode) of the component 13b has been detected when the ratio L2/L1 of 1tL1.12 is less than or equal to a certain value.

Further, in the embodiment described above, windows 378 to 37d are provided near the four corners of one component.
As shown in the figure, windows 38a to 38e may be provided at the four corners and the center of one component 13.

Further, in the above-described embodiment, the determination criterion 1 rear 33 is set to 1 for each component, but it is also possible to treat each component as a whole and find a common determination criterion area for each component.

(Effects of the Invention) As explained above, according to the present invention, the optimum characteristic parameters for checking the mounting condition of the component are automatically selected from the image data obtained by illuminating the printed circuit board. It is also possible to automatically create judgment standard data.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the printed circuit board inspection apparatus according to the present invention, FIG. 2 is a dimensional diagram showing an example of the taving operation of the same embodiment, and FIG. 3 is a diagram showing the inspection operation of the same embodiment. Flowchart showing an example, FIG. 4 is a schematic diagram showing an example of a window used in the same example, FIG. 5 (A>,
(B) is a schematic diagram showing an example of distribution of bare board parameters in the same example, FIGS. 6(A) and (B) are schematic diagrams showing an example of distribution of pQ printed board parameters in the same example, and FIG. Figures (A) and (B) are schematic diagrams showing distribution examples of bare board parameters and ** printed circuit board parameters in the same example, and Figures 8 (A) to (C) are parts in the same example. FIG. 9 is a schematic diagram for explaining another determination method of the printed circuit board inspection apparatus according to the present invention, and FIG. 10 is a schematic diagram showing another example of the window used in the present invention. , FIG. 11 is a block diagram showing an example of a conventional automatic inspection device. 9...Bare board, 10-1...Reference printed circuit board, 1
0-2... Printed circuit board to be inspected, 15... Imaging unit,
25...Storage unit (teaching table), 31...
- Image cropping unit, judgment standard data creation unit (control unit). Patent applicant Agent: Tateishi Electric Co., Ltd.
Patent attorney Tetsuji Iwao (1 person) Figure 2 Figure 4

Claims (1)

[Claims] Based on the judgment criteria data stored in the storage unit,
In a printed circuit board inspection apparatus that inspects an image obtained by imaging a board to a printed circuit board to be inspected to inspect a mounting state of components of the printed circuit board to be inspected, an imaging unit that captures images of a reference printed circuit board and a bare board; , an image cutting unit having a plurality of windows necessary for respectively cutting out a component image and a bare board image of the component placement area from the reference printed circuit board image and the bare board image obtained by the imaging unit; A printed circuit board inspection device comprising: a judgment standard data creation section that creates judgment standard data based on the distribution of the features of each component image obtained by the cutting section and the features of each bare board image. .