JPS62298750A - Inspecting device for printed circuit board - Google Patents

Abstract

PURPOSE:To enable inspection on whether a part is mounted without positional deviation regardless of variations in the state of board, by comparing feature parameters of an image before and after the position at which the part is mounted. CONSTITUTION:A printed circuit board inspector is provided with a preprocessing section 11 arranged before a mounter 10, a buffer memory 12 for memorizing an output of the preprocessing section 11 temporarily and a main processing section 13 arranged after the mounter 10 and compares an image of a unloaded board 9a as obtained a camera unit 17 at the preprocessing section 11 with an image of a loaded board 9b as obtained by a camera unit 28 at the main processing section 13 to perform an inspection on whether parts 8 are mounted correctly on the board 9b or not. The preprocessing section 11 has an X-Y table section 16 and the camera unit 17 and a preprocessing section body 18 which processes the image obtained by the camera unit 17. The main processing section 13 has with an X-Y table section 27, the camera unit 28 and a main processing body 29 which processes an image signal obtained by the camera unit 28 and image data memorized in the buffer memory 12.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Industrial Application Field) The present invention is a method of processing an image obtained by capturing an image of a printed circuit board to be inspected on which components are mounted to Printed circuit board inspection equipment that inspects 1 to 10 parts of the board for misaligned parts: a 1. :Related.

(Prior art) When using automatic ζ7 mount mounting when installing various chip parts such as resistors and semi-I9 (4-inch) on a printed circuit board in a marine 1-41, Parts may be mounted and mounted.

For this reason, when using such automatic marine equipment, etc., check the printed circuit board after mounting to make sure that the correct chip components are in the correct position and in the correct orientation (117 direction) on the printed circuit board. I don't care if it's mounted, again! l((It is necessary to check whether it has fallen or not.

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 d 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 device.

The automatic inspection device shown in this figure compares the reference data inputted in advance with the inspection data obtained by ffdF(+) of the printed circuit board 1 to ensure that all the components 2 are placed on the printed circuit board 1 to be inspected. The keyboard 3 and storage unit 4
, -[v camera 5 , processing section 6 , and display section 7 .

The keyboard 3 is equipped with various keys such as function keys and numeric keys, and the keyboard 3 is equipped with various keys such as function keys and numeric keys. Characteristic data such as color data of the part 2, position data for mounting, posture data for mounting, shape data, etc., and each part 2 of the printed circuit board 1 based on these characteristic data.
When the tolerance value data and the like necessary for inspecting the quality of the data are input, these data are supplied to the storage section 4.

The storage section 4 is equipped with a RAM (random access memory), etc., and stores each 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 taken by the TV camera 5, and transfers the printed circuit board 1 to the printed circuit board 1. Each fi characteristic data (
In addition to extracting the data to be inspected), it also extracts the data to be inspected according to the data stored in the storage unit 4, and The check results are supplied to the display unit 7 and the quality of each part 2 is displayed.

By the way, in such a conventional automatic inspection device, the keyboard 3
Input from! ;i T\ data and printed circuit board 1
Since the printed circuit board I J-1: Component 2 is mounted correctly or not, there is a large variation in the printed circuit board 1. Sometimes, there is a problem in that the range of movement of the data to be inspected is so large that the mounted state of the component 2 cannot be inspected.

In particular, when the component 2 is soldered using cream solder, the image signal S1 of the part where the component 2 is placed changes greatly depending on the application state of the cream solder, as shown in FIG. 10 (A>). When binarizing with the threshold value TH, even if component 2 is not mounted in this area, a signal NS2 indicating that the component is present will appear at the middle of the pixel as shown in Figure 10 (F3), and the position of component 2 will be Misalignment,
In many cases, it becomes impossible to detect the dropout.

In view of the above circumstances, the present invention has been developed so that even if the condition of the printed circuit board varies before the components are mounted, all the components can be placed on the printed circuit board without misalignment after the components are mounted on the printed circuit board. The object of the present invention is to provide a printed circuit board inspection device that can inspect whether the printed circuit board is mounted or not.

(Means for Solving the Problems) In order to solve the above problems, the printed circuit board inspection apparatus according to the present invention provides a printed circuit board inspection apparatus that inspects the ten parts of the printed circuit board based on characteristic parameters obtained by visualizing the printed circuit board. In the board inspection apparatus, a first imaging unit that images the printed circuit board before components are mounted on the printed circuit board, and a second predetermined imaging unit that images the printed circuit board after the components are mounted on the printed circuit board. a determination unit that compares the characteristic parameters of the printed circuit board image obtained by the first imaging unit and the characteristic parameters of the printed circuit board image obtained by the second imaging unit to inspect the components on the printed circuit board; It is characterized by the fact that it is equipped with

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

A printed circuit board inspection apparatus 1j shown in this figure includes: a preprocessing section 11 disposed in front of a mounter 10;
The main processing section 13 is provided after the mounter 10, and the unrealized MM board 1q is processed by the image 1117 of the preprocessing section 11. (Printed circuit board before parts are mounted) 9
a image and l1ifllllj of the main processing unit 13
The image of the mounting board (printed board after mounting the component) 9b obtained by step 128 is compared with the image of the mounting board 9b to check whether the component 8 is correctly mounted on the mounting board 9b.

#J processing section 11 includes an
- An image removal device (for example, a color TV camera, etc.) 17 that takes an image of the unmounted board 9a placed on the Y table section 160 and positioned; and an image of the unmounted board 9a obtained by this image removal device 17; The preprocessing section main body 18 includes an A/D conversion section (analog/digital conversion section) 19 as shown in FIG.
-Y stage controller 20, memory 21, and CP
A central processing unit (U) 22 and two interfaces 23, 24 are provided.

One A/D converter converts the unmounted board 9a that has been removed by the fin imager 17 under the control of the CPU 22.
The image signal is A/D converted to create image data, and this is supplied to the CPU 22.

In addition, the X-Y stage controller 20
22, and each pulse motor (
(not shown).
The XY table unit 16 is controlled based on the output of the CPLJ 22.

The memory 21 also includes a RAM (Random Access Memory) used as a work area for the CPU 22, and a ROM (Random Access Memory) in which the operations of the CPU 22 are written.
Read-only memory), CPU22
performs various processes while accessing this memory 21.

Further, one interface 23 is connected to the CPtJ22.
This is a communication interface 1- that connects the main processing unit 13 and the mounter 10, and this interface 2
3, the CPU 22 connects to the main processing unit 13 through
and the mounter 10.

Also, the other interface 24 (the CPIJ2
2 and the buffer memory 12, and the CPLJ 22 transfers the image data obtained by the A/D converter 19 to the buffer memory 12 via this interface 24.

The buffer memory 12 is configured to store the image data supplied from the preprocessing section 111), and the internal data stored here is stored in the main processing section 1.
3 are sequentially read out.

The main processing section 13 includes an X-Y table section 27 on which the mounting board 9b carried out from the mounter 10 is placed, and a
)X Y Chi 11 Part 27-t, T 4.1.1!
A dancing image machine (
For example, a color TV camera, etc.) 28, a main processing unit body that processes the image signal of the mounted board 9b obtained by this VA imager 28 and the image data of the unmounted board 9a stored in the buffer memory 12. As shown in FIG. ! =, A/D
Conversion unit 32, image processing unit 33, and XY stage]
1-n-ra 35, memory 36, etc., CPU 37
A keyboard 38, a CRT display 39, a printer 40, and a teaching table 42 are provided.

One interface 30 is a CP IJ 37, etc.
There is an interface connected to the preprocessing section 11, and the CPU 37 issues commands to the preprocessing section 11 via this interface 30.
A response signal output from the Art 9j1 tapping section 11 is received via this interface 1-30.

The other interface 31 connects the CPU 37 and the buffer memory 12, and the CP tJ 37 reads image data of the unmounted board 9a from the buffer memory 12 via this interface 31.

7j When the A/D conversion section 32 is supplied with an image signal from the image pickup device 28, it A/D converts this to create image data, and supplies this to the CPU 37.

Further, the memory 36 includes a RAM and the like, and is used as a processor for the CPU 37.

Furthermore, when the image processing section 33 is supplied with image data from the CPjJ 37, it binarizes this image data, and the data obtained here is used to
37.

Furthermore, the teaching table 42 is equipped with a floppy disk device, etc., and during teaching, the C
When a data file etc. is supplied from the PU 37, it is stored, and when the CPtJ 37 outputs a transfer request during inspection, this data file etc. is read out in response to this request and supplied to the CPU 37 etc. ri°ru.

Further, the X-Y stage controller 35 uses the CPU 3
The X-Y table section 27 is controlled based on the output of the CPU 37. do.

The CR7 display 39 is equipped with a cathode ray tube (CRT), and when it is supplied with image data, judgment results, key manual data, etc. from the CPU 37, it displays these on the screen.

Further, when the printer 40 is supplied with the judgment result etc. from the CPLJ 37, it prints it out in a predetermined format (format).

Further, the keyboard 38 is provided with various keys necessary for inputting information such as manipulation information, and the information etc. input from this keyboard 38 is supplied to the CPU 37.

In addition, the CPU 37 is equipped with a ROM in which the operations of the microprocessor 4 and the microprocessor are written, and it controls each part of the device based on the program stored in this ROM. and process each scale data.

Next, the u+ fl of this embodiment will be explained with reference to the flowcharts shown in FIGS. 4(A) and 4(b).

First, when a new type of printed circuit board is to be inspected, data regarding the printed circuit board is taught prior to the inspection.

In this teaching operation, first, in step ST1 of the flowchart shown in FIG. 4(A), the CPU 37 initializes each part of the apparatus and puts these parts into a teaching mode.

Next, in step ST2, the CPLJ37 checks whether a teaching board (illustrated path) has been set on the X-Y table section 270, and if it has been set, it causes the imaging t128 to take an image of this, and this imaging The image signal obtained by the operation is converted into image data by the A/D converter 32, and this is stored in the memory 26 in real time.

In this case, the teaching board is a board for teaching the device the position and shape of the component 8 to be mounted on the unmounted board 9a, and the base board portion is painted black. The parts are painted with white paint so that the image can be easily binarized.

Next, when the illumination of the teaching board is completed, the CPU 37 sequentially reads out the image data of the teaching board from the screen 26 and supplies it to the image processing section 33 to binarize the image data. let

Then, if a binarized image is obtained, the CPU 37
The image of each part is extracted from the value image, and the fifth image is extracted for each part 8.
A window 43 as shown in the figure is created and stored in the teaching table 42.

Next, in step ST3, the CPU 37 checks whether the first unmounted board 9a is set on the X-Y table section 16, and if it is set,
The CPtJ22 is controlled to cause the image pickup device 17 to image this, and the image signal obtained by this image pickup operation is sent to A.
The /D converter 19 converts the data into image data, and transfers this to the buffer memory 12.

When this imaging operation is completed, the CPU 37 operates a button (as shown in the figure) provided in the preprocessing section 11 to remove the floor mounting board 9a from the X-Y table section 16 and place it on the mount 1. (11, T is carried in.

As a result, the mounter 10 starts its operation and starts mounting the determined component 8 at the determined position on the unmounted board 9a.

Further, in parallel with the operation of the mounter 10, the CPU 37 causes the window data stored in the teaching table 42 to be transferred to the image processing section 33 in step ST4, and also transfers the window data stored in the teaching table 42 to the image processing section 33, and also transfers the window data stored in the teaching table 42 from the buffer memory 12 to the unmounted board 9a.
The image data is read out and processed by the image processing section 33.
The image of the window 43 portion is cut out from this image data.

Next, the CPU 37 extracts various feature parameters from the image of this window 43 portion, and stores them in the teaching table 42 as feature parameters of the unmounted board 9a.

In this case, as the feature parameter, one of the R, G, and 13 signals constituting the image of the window 43 portion, or a parameter obtained by combining and extracting these signals, etc. can be used.

After this, this mounter 10 finishes its operation and the part 111
Push out the board (mounted board) 9b to the pudding 1 in the bay toward the main processing section 13 side, and place it on the X-Y table section 27
In step ST5, this mounting board 9b is placed on the 1st imager 28.
At the same time, the image signal obtained by this nine-image operation is converted into image data by the A/D converter 32, and this is stored in the memory 36 in real time.

Next, in step ST6, the CPU 37 causes the window data stored in the teaching table 42 to be transferred to the image processing section 33, and reads the image data of the mounting board 9b from the memory 36, and transfers this to the image processing section 33. Then, the image of the window 43 portion is cut out from this image data.

Next, the CPtJ 37 extracts various feature parameters from the image of this window 43 portion, and stores them in the teaching table 42 as feature parameters of the mounting board 9b.

This ICPLJ37 is this teaching table 42
from the characteristic parameters of the unmounted board 9a and the mounted board 9a.
The characteristic parameters are read out and the difference between them is determined, and for each component 8, the type of parameter most suitable for detecting the presence or absence of the component, positional deviation, etc., and its processing procedure are determined, and in step ST8 This is filed in the teaching table 42 and the teaching operation is completed.

Further, when this teaching operation is completed, a continuous inspection operation of printed circuit boards starts.

In this test operation, first, in step 5T10 of a flowchart shown in FIG. 4(8), the CPU 37 initializes each part of the apparatus and puts these parts into a test mode.

Next, the M-CPU 37 checks whether the second unmounted loading board 9a is set on the x-Y table section 16 in step 5T11, and if this is set,
The CPU 22 is controlled to cause the imaging device 17 to take an image of this, and the image signal obtained by this imaging operation is sent to the A/
The D converter 19 converts it into image data and transfers it to the buffer memory 12.

When this imaging operation is completed, the CPU 37 moves a button etc. installed in the preprocessing section 11 to remove the unmounted board 9a from the X-Y table section 16, and removes it. Bring it into mounter 10.

As a result, the mounter 10 starts operating and starts loading the parts 8 onto the unmounted board 9a.

Also, the operation of this mount 10! l(, line, CI)
U37 is teeing table 4 at step 5T12.
The window data stored in 2 is processed in-house by 1 processing unit 3.
Transfer to 3 and 11 (J, said buffer) 'Memory 1
The image data is read out from window 2 and transferred to the image processing section 33, and the image data is read out from window 4.
Cut out three parts of the image.

Next, CP LJ 37 moves to teaching table 42
After reading out the optimal parameter type for each component 8 and its processing procedure, the window 43 is
The partial image is processed to extract optimal parameters for each component 8, and these are stored in the memory 36 as characteristic parameters of the unmounted board 9a.

After this, the mounter 10 pushes out the parts 0# & bay pudding 1 to board (mounted board > 9b) to the main processing section 13 side,
If this is placed on the X-Y table section 270, CPtJ3
7, in step 5T13, the mounting board 1 board 9b is imaged, and the image signal obtained by this imaging movement is converted into image data by the A/D converter 32, and this is stored in the memory 36 in real time. .

Next, the CPU 37 stores this memory 3 in step 5T14.
The image data stored in the window 43 is transferred to the image processing unit 33, and the image data of the window 43 portion is cut out from this image data, and the image of the window 43 portion is transferred to the component 8 stored in the teaching table 42. The optimal type of feature parameters determined for each part 8 are extracted by processing in each processing procedure, and are stored in the memory 36.

-19=The CPLJ37 then stores the memory 36 in step 5T15.
characteristic parameters of the unmounted board 9a stored in the
The characteristic parameters of the mounting board 9b are each read out, and these are compared in terms of the pixel ψ position, and the mounting board 9b is
It is determined whether the characteristic parameter of is the parameter of part 8.

In this case, as shown in FIG. 6(A), if the characteristic parameter P1 of the future mounting board 9a and the characteristic parameter P2 of the mounting board 9b for one window 43 match in pixel units, the CPU 37 Feature parameter P
2 is determined to be the parameter of the ν plate portion.

Moreover, as shown in FIG. 6(B), each feature parameter P1. If P2 does not match on a pixel-by-vixel basis, CPtJ 37 let.

This feature parameter P2 is determined to be the parameter of the component 8.

Based on this determination result, the CP LJ 37 determines whether all the components 8 are mounted on the mounting board 9b without any displacement, and then displays the determination result on the CRT display using the ST20-P5T16. 39 and the printer 40 and display this 1! or print it out.

In this way, in this embodiment, the unmounted board 9a,
The mounted boards 9b obtained by mounting the component 8 on this unmounted board 9a are each imaged, and these unmounted boards 9
Since the image of a and the image of the actual 6g board 9b are compared to check whether all the components 8 are mounted on the mounted board 9b without any ml deviation, the unmounted board 9a is Even if the condition varies, it is possible to accurately inspect for falling off, misalignment, etc. of the component 8.

FIG. 7 is a block diagram showing a second embodiment of the printed circuit board inspection apparatus according to the present invention. In this figure, parts corresponding to those in FIG. 1 are given the same reference numerals.

The printed circuit board inspection apparatus shown in this figure is different from the apparatus shown in FIG. The A/D converter 4 provided in the main processing unit main body 29-2 as shown in FIG.
4, the image signal of the unmounted board 9a is A/D converted.

Even in this case, the CPU 37 is made to compare the image data of the unmounted board 9a and the image data of the mounted board 9b,
It can be inspected whether all the components 8 are mounted on the mounting board 9b without any misalignment.

Furthermore, in each of the embodiments described above, the preprocessing section 11.11
-2 and the main processing section 13.13-2 on the mounter 10.
The pre-processing section 11.11-2 and the main processing section 13.13-2 are placed before and after the parts 8 to inspect the mounted state of the component 8. If placed before and after a coating machine, reflow oven, etc.), it is also possible to inspect the application status of solder paste, adhesive application, etc.

Further, in each of the embodiments described above, a color TV camera is used as the TV camera, but it may be replaced with a monochrome TV camera, or a line sensor or the like may be used.

Furthermore, in the embodiment described above, two mud statue machines 17.2
However, in cases where the mounter 10's 1j board loading inlet and substrate loading inlet are adjacent to each other, or if the inspection speed is slow, it may be necessary to use 1' color capture machine 1. : J: The unmounted board 9a and the mounted board 9b may be imaged in parallel.

(Effects of the invention) As explained above, according to the present invention, the condition of the printed circuit board to be inspected varies, and it is possible to inspect whether components are correctly mounted on this printed circuit board. .

[Brief explanation of the drawing]

FIG. 11 is a circuit block diagram showing a first embodiment of the present invention;
Figure 2 is a detailed circuit block diagram of the pre-processing unit shown in Figure 1, Figure 3 is a detailed circuit block diagram of the main processing unit shown in Figure 1, and Figures 4 (A) and (B). are each this first
5 is a schematic diagram showing an example of a window used in this first embodiment, and FIG. 6 (Δ) and (F3) are each obtained in this first embodiment. FIG. 7 is a circuit block diagram showing an example of the characteristic parameters of the present invention, and FIG. 8 is a detailed diagram of the main processing section body shown in FIG. 7. FIG. 9 is a circuit block diagram showing an example of a conventional board inspection apparatus, and FIGS. 10(A) and (11) are waveform diagrams for explaining the operation of the conventional board inspection apparatus. 8...Parts, 9a...Print υ analysis (Mimitsu 44 top (
board), 9b...Printed circuit board (actual $1 board), -
10...Mounter, 11...Preprocessing section, 12...
Buffer memory, 13... Main processing section, 17...
1st clay image part (an imager), 28... a second mud image part (an imager), 2')... a main processing unit body (judgment part). Agent: Patent Attorney Tetsuji Iwakura (1 Sen) No. 41 (A)
) Figure 4 (B) 5th page? Figure 33

Claims (1)

[Claims] A printed circuit board inspection device that inspects components on the printed circuit board based on characteristic parameters obtained by imaging the printed circuit board, comprising: a first imaging unit that photographs the printed circuit board before the components are mounted on the printed circuit board; , a second imaging section that images the printed circuit board after components are mounted on the printed circuit board; characteristic parameters of the printed circuit board image obtained by the first imaging section; and printed circuit boards obtained by the second imaging section. A printed circuit board inspection apparatus comprising: a determination section that compares feature parameters of images to inspect components on the printed circuit board.