JP3289070B2 - Mounted parts inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounted on, for example, a printed circuit board (hereinafter, simply referred to as a "substrate"). The quality of the mounting, etc., related to the mounted component inspection device used to inspect each, in particular, the present invention is any required to inspect the mounting quality of mounted components from the color image obtained by imaging the board The present invention relates to a mounted component inspection apparatus having a function of extracting a color pattern.

[0002]

2. Description of the Related Art Conventionally, visual inspection has been performed to inspect the mounting quality of mounted components on a substrate to be inspected (the components before soldering and those after soldering are collectively referred to as “mounting”). Have been done. However, in this type of visual inspection, an inspection error is unavoidable, the inspection result varies depending on the inspected person, and the inspection processing capacity is limited.

[0003] In recent years, a mounted component inspection apparatus has been put to practical use for automatically inspecting the mounting quality of a board on which a large number of components are mounted using image processing technology. This mounting component inspection device is for automatically inspecting the soldering state of components mounted on a board, and includes three light sources that irradiate three primary color lights having different incident angles to the component mounting position, and a soldering device. The color television camera includes a color television camera that captures an image of light reflected from the surface of the part, and a control processing unit that processes the color image obtained by the color television camera to determine whether the soldering state is good or not.

[0004] When using the above mounted component inspection apparatus, it is necessary to teach the mounted component inspection apparatus for each type of board about what components are to be mounted and how to mount them before the inspection. This teaching operation is called "teaching". The inspection data of the mounted component includes information on an inspection region, information on an image in the inspection region, a determination criterion, and the like, in addition to the position and type of the component mounted on the substrate to be inspected.

The information on the image includes color parameters such as a binarization threshold for extracting an arbitrary color pattern from the color image. The color pattern is used to extract characteristic parameters necessary for determining the mounting quality of the mounted component.In order to realize proper board inspection, it is necessary to accurately extract the color pattern. Is assumed.

The above-mentioned color pattern is obtained by performing a binarization process by comparing each image data obtained by A / D conversion of a color image signal of three primary colors with a binarization threshold value for each hue for each pixel. FIGS. 9 and 10 show an example of a binarization processing method for a color image.

FIG. 9 shows the relationship among lightness, hue, and saturation, which are the color elements.
Red, yellow, green, blue, and purple are arranged on the circumference in the order of wavelength. Hue is represented by a ring 32 centered on the vertical axis, and saturation is represented by radiation 33. The hue and the saturation are collectively referred to as chromaticity, and the chromaticity diagram is a chromaticity diagram.

FIG. 10 is a typical XY chromaticity diagram in which the XYZ color system is displayed in XY. In the XY chromaticity diagram, when an arbitrary color area 34 is indicated by oblique lines, X = ru, X
= Rd (where ru ≧ rd), these functions are expressed as ru and rd on the X-axis (R-axis corresponding to red hue).
, A straight line that is orthogonal to the X axis and intersects the spectrum locus. Similarly, if functions of Y = gu and Y = gd (where gu ≧ gd) are expressed, these functions pass through each point of gu and gd on the Y axis (G axis corresponding to green hue), and It is a straight line that is orthogonal and crosses the spectrum locus.

The XY chromaticity diagram is an XY representation of the XYZ color system, and has a relationship of X + Y + Z = 1 (Z is the B axis corresponding to the blue hue).
u and bd (where bu ≧ bd) are given by the following equations.

[0010]

(Equation 1)

[0011]

(Equation 2)

This binarization processing method is characterized in that the constants ru, gu, and bu for the red, green, and blue chromaticities r, g, and b are set to the upper limit value of the chromaticity binarization threshold, rd, gd, b
d is set in advance to the lower limit of the binarization threshold of chromaticity, and constants Lu and Ld for lightness L are set in advance to the upper limit and the lower limit of the binarization threshold of lightness, respectively. When a color image is input from a camera, the lightness L and the red, green, and blue chromaticities r, g,
b is calculated for each pixel by the following equations (3) to (6), the brightness calculation data is compared with the upper limit Lu and the lower limit Ld, and the calculation data of each chromaticity is calculated as the upper limit ru, gu, b
The binarization process is performed on the color input image by comparing u with the lower limit values rd, gd, and bd, respectively.

[0013]

(Equation 3)

[0014]

(Equation 4)

[0015]

(Equation 5)

[0016]

(Equation 6)

[0017]

The setting of each binarization threshold value used in the above-mentioned binarization processing is performed by an operator during teaching by looking at a color image displayed on a screen for each part. And instructing this to the mounted component inspection apparatus. However, in such a teaching method, the burden on the operator increases, a great deal of labor and time are required for the teaching operation, and the determined binarization threshold varies depending on the operator, and the teaching data lacks accuracy. There's a problem.

The present invention has been made in view of the above-mentioned problems, and is intended to provide a color pattern which is an extraction condition of an arbitrary color pattern necessary for inspecting the mounting quality of a mounted component from a color image.
The purpose is to set parameters accurately and easily.

[0019]

A mounting section according to the present invention.
Article inspection apparatus, which has a function of extracting any color patterns required to test the mounting quality of a color image from the mounted component obtained by imaging the mounted components on the board, before
Display means for displaying the color image, the display means
Using the color image displayed in the column, the color pattern
Setting means for setting color parameters required for extraction
I do. The setting unit is configured to display a color displayed on the display unit.
-Specify the display area of the color pattern to be extracted in the image.
Specifying means for determining, for the area specified by the specifying means, calculating means for calculating values relating to brightness, chromaticity and white, and displaying the calculated values by the calculating means in the display
Means, and in this display state,
Control means for receiving an input of a set value of a color parameter;
Registration means for registering the set value received by the control means;
Is provided.

In the mounted component inspection apparatus according to the second aspect of the present invention, the designating means may include a color pattern of the color pattern to be extracted.
Means for designating a display area at one point in the area,
The calculating means calculates the brightness, chromaticity, and whiteness of the pixel using the color image information of the pixel corresponding to the point specified by the specifying means .

According to a third aspect of the present invention, in the mounting component inspection apparatus, the designating means includes a color pattern of the color pattern to be extracted.
Means for designating the display area with a plurality of points in the area, wherein the calculating means uses the color image information of each pixel corresponding to each point designated by the designating means ,
The brightness, chromaticity, and whiteness of the pixel are calculated, and at least one of a maximum value, a minimum value, an average value, and a standard deviation is calculated for each of the calculated values of brightness, chromaticity, and whiteness. one
On the other hand, in the mounted component inspection apparatus according to the fourth aspect of the present invention,
A designation area for displaying the color pattern to be extracted;
Is specified by an area of a predetermined size included in that area
Means, wherein the calculation means is designated by the designation means
Using the color image information of each pixel in the
Calculate the brightness, chromaticity, and whiteness of the pixel from
For each of the calculated values of chromaticity and whiteness, the maximum and minimum values,
Calculate at least one of average and standard deviation
are doing.

A mounting component inspection apparatus according to a fifth aspect of the present invention.
Then, the control means, as a set value of the color parameter,
Indicates the extraction range for each of brightness, chromaticity, and whiteness
Accept upper and lower limit values
You.

[0023]

[Action] Look at the color image display and extract it for inspection.
When you specify the display area of the color pattern you want,
Values related to lightness, chromaticity, and white are calculated for each area.
The calculated value is displayed. In addition, color parameters
Data setting values are accepted and registered.
In the inspection, the color pattern is
Are extracted.

According to the second aspect of the present invention, the extracted and
When the display area of the desired color pattern is designated by one point, the brightness, chromaticity, and white of the pixel are calculated from the color image information of the pixel corresponding to the point, and each calculated value is displayed.
It is. On the other hand, in the mounted component inspection apparatus of claim 3,
Specify multiple points in the display area of the desired color pattern
The mounting component inspection apparatus according to claim 4
Is a predetermined size within the display area of the color pattern to be extracted.
Corresponding to each specification by specifying the area of
Based on color image information for multiple pixels
Maximum and minimum for each of degree, chromaticity and whiteness
At least one of the value, the average, and the standard deviation,
Each calculated value is displayed.

According to the fifth aspect of the present invention, the brightness, chromaticity, and whiteness
Upper and lower limits indicating the extraction range for each
Is entered, these values are registered as color parameters
It will be used for the subsequent inspection.

[0026]

FIG. 1 shows the overall configuration of a mounted component inspection apparatus according to an embodiment of the present invention. This mounting component inspection apparatus is obtained by imaging a substrate 1T to be inspected and characteristic parameters of an inspection area of each component 2S on the reference substrate 1S obtained by imaging the reference substrate 1S having good mounting quality. The X-axis table unit 3 and the Y-axis table unit are used to inspect the mounting quality of each component 2T by comparing the characteristic parameters of the inspection area of each component 2T on the substrate 1T to be inspected. 4, a light projection unit 5, an imaging unit 6, a control processing unit 7, and the like.

The X-axis table unit 3 and the Y-axis table unit 4 each include a motor (not shown) that operates based on a control signal from a control processing unit 7, and the X-axis table unit is driven by driving these motors. The unit 3 moves the imaging unit 6 in the X-axis direction, and the Y-axis table unit 4 controls the substrates 1S and 1T.
Is moved in the Y-axis direction.

The light projecting unit 5 is formed by three annular light sources 9, 10, and 11 having different diameters and simultaneously irradiating red light, green light and blue light based on a control signal from the control processing unit 7. The light sources 9, 10, 11 are centered on the position directly above the observation position and are positioned in directions corresponding to different elevation angles as viewed from the observation position.

The image pickup unit 6 is a color television camera, and is positioned downward just above the observation position. As a result, the reflected light from the surfaces of the substrates 1S and 1T to be observed is imaged by the imaging unit 6, converted into three primary color signals R, G, and B and supplied to the control processing unit 7.

The control processing unit 7 includes an A / D conversion unit 12,
Memory 13, image memory 24, teaching table 1
4, an image processing unit 15, a determination unit 16, an XY table controller 17, an imaging controller 18, a control unit 19, a display unit 20, a printer 21, a keyboard 22, a floppy disk device 23, and the like. , The color signal R for the reference substrate 1S,
G and B are processed, a predetermined color pattern is extracted from the inspection area of each component 2S having a good mounting state, and a characteristic parameter is calculated from the color pattern to create a determination data file.

In the inspection mode, the control processing section 7 processes the color signals R, G, B for the substrate 1T to be inspected, and extracts a predetermined color pattern from the inspection region of each component 2T on the substrate 1T to be inspected. Then, a characteristic parameter is calculated from the color pattern to create an inspection data file. Then, the inspection data file is compared with the determination data file, and the inspection result is obtained from the comparison result.
The mounting quality is automatically determined for each component 2T on T.

FIG. 2 shows the cross-sectional configuration of the solder 25 when the soldering is good, when the component is missing, or when the solder is insufficient, and the image pattern, red, The relationship between each hue pattern of green and blue is exemplified in a list, and a clear difference appears between any of the hue patterns, so that it is possible to determine the presence or absence of a component and the quality of soldering. .

Returning to FIG. 1, the A / D converter 12 A / D converts the three primary color image signals from the imaging unit 6 to generate three primary color image data R, G, B, R, G, and B are stored in the image memory 24 in pixel units. The memory 13 stores lightness L, chromaticities r, g, b,
The control unit 1 includes a threshold table for whiteness w and the like.
9 is used as the work area.

FIG. 3 shows the contents of the threshold value table TB set in the memory 13. As the binary threshold, the upper limit Lu and the lower limit Ld of the lightness L, the chromaticities r of the three primary colors, r, The upper limit values ru, gu, bu and lower limit values rd, gd, bd of g and b, the upper limit value wu and the lower limit value wd of whiteness w (hereinafter, these are collectively referred to as “color parameters”) are set, respectively. I have.

In the figure, a use switch (SW) is used to designate a target for setting a binarization threshold value. When the use switch is on, an upper limit value and a lower limit value are set and a specific value is set. A binarization process for extracting a region is performed, and if the use switch is off, a binarization process for extracting the entire region without setting an upper limit value and a lower limit value is performed. . When the switch used is off,
Specifically, the maximum value as the upper limit value (1.0 for chromaticity)
Is set as a lower limit value and a minimum value (0 for chromaticity) is set.

Returning to FIG. 1, the image processing unit 15
The lightness L, the chromaticities r, g, b, and whiteness w of the three primary colors are calculated in pixel units from the red, green, and blue image data R, G, and B supplied via the pixel unit 9, and these are determined by the threshold. After performing the binarization process by comparing with the color parameters of the value table TB, the inspection data file and the determination data file are created and supplied to the control unit 19 and the determination unit 16.

The teaching table 14 stores the judgment data file supplied from the control unit 19 during teaching, and stores the judgment data file in response to this request when the control unit 19 outputs a transfer request during inspection. It is supplied to the control unit 19 and the determination unit 16.

The judgment section 16 compares the judgment data file supplied from the control section 19 at the time of inspection with the data file to be inspected transferred from the image processing section 15 and determines each part 2T of the substrate 1T to be inspected. The quality of the soldering state is determined, and the determination result is output to the control unit 19.

The image pickup controller 18 includes an interface for connecting the control section 19 to the light projecting section 5 and the image pickup section 6, and adjusts the light amounts of the light sources 9 to 11 of the light projecting section 5 based on the output of the control section 19. And controls to maintain the mutual balance of each hue light output of the imaging unit 6.

The XY table controller 17 controls the controller 1
An interface for connecting the X-axis table section 9 to the X-axis table section 3 and the Y-axis table section 1 is provided, and the X-axis table section 3 and the Y-axis table section 4 are controlled based on the output of the control section 19.

When image data, inspection results, key input data, and the like are supplied from the control unit 19, the display unit 20
This is displayed on the display screen, and when the inspection result or the like is supplied from the control unit 19, the printer 21 prints out the inspection result in a predetermined format.

The keyboard 22 is used for operating information, the reference board 1
There are provided various keys necessary for inputting information about S and the substrate 1T to be inspected, color parameters, and the like. Key input data is supplied to the control unit 19. The control unit 19 includes a microprocessor or the like, and controls the operation of the mounted component inspection apparatus in teaching and inspection according to the procedures shown in FIGS.

FIG. 4 shows a control procedure of teaching by the control processing section 7. First, in step 1 of the figure, the operator operates the keyboard 22 to register the name of the board to be taught, and inputs the board size by key, and then in step 2 the mounting quality of each component is good. The reference substrate 1S is set on the Y-axis table 4 and the start key is pressed.

Next, in Step 3, the origin and the upper right and lower left corners of the reference substrate 1S are imaged by the imaging unit 6 and the actual size of the reference substrate 1S is input according to the position of each point. X-axis table unit 3 based on input data
Then, the reference substrate 1S is positioned at the initial position by controlling the Y-axis table unit 4.

The reference substrate 1S has a good mounting quality in which a predetermined component 2S is properly mounted at a component mounting position. When the reference substrate 1S is positioned at an initial position, the following steps are performed. At 4, the imaging unit 6 is moved to the reference substrate 1S.
The upper region is imaged to teach the mounting position of the first component 2S. In the next step 5, the inspection region for the component 2S is taught, and in step 6, the criterion for inspection in this inspection region is taught.

In the next step 7, the color parameters in the inspection area are taught. FIG. 5 shows a detailed procedure of Step 7;
The operator operates the keyboard 22 while viewing the color image 28 as shown in FIG. 6 displayed on the display unit 20, moves the cursor 29 to the area of the color pattern to be extracted, and designates an arbitrary point.

Now, the position of the pixel A corresponding to the designated point is (x, y), and the image data of the three primary colors for this pixel A is R (x, y), G (x, y), B (x, y). y)
Then, the image processing unit 15 executes the following operation to obtain the lightness L (x, y) of the pixel A and the red chromaticity r
(X, y), green chromaticity g (x, y), blue chromaticity b (x,
y) and whiteness w (x, y) are calculated (step 7).
2).

[0048]

(Equation 7)

[0049]

(Equation 8)

[0050]

(Equation 9)

[0051]

(Equation 10)

[0052]

[Equation 11]

In the next step 7-3, the above calculated values are displayed on the same display screen of the display unit 20. In the display example shown in FIG. 6, in a frame 27 displayed on the display screen,
The calculated lightness L (x, y), each chromaticity r (x, y), g
The values of (x, y), b (x, y), and whiteness w (x, y) are displayed, respectively.

Next, the operator refers to the values displayed in the frame 27 and refers to the upper limit Lu, ru, gu, bu, wu and the lower limit Ld, for each of the brightness, chromaticity, and whiteness. rd, gd, bd, wd on keyboard 2
2 is operated to enter a key (step 7-4). Next, the extracted pattern is displayed on the display unit 20 using the color parameters to determine whether or not the threshold value taught is appropriate. If the threshold value is not appropriate, the process returns to step 7 # 1 to specify again. Follow similar steps and, if appropriate,
Step 7-5 becomes "YES", and the setting of the color parameters is completed.

In the above embodiment, an arbitrary point is designated in step 7-1, and the brightness, chromaticity, and whiteness values of the pixel A corresponding to the designated point are calculated. After calculating the brightness, chromaticity, and whiteness of each pixel corresponding to each point, calculate and display at least one of the maximum value, minimum value, average value, and standard deviation of the calculated values You may make it.

As shown in FIG. 7, a rectangular area B is defined by pixels A1 and A2 by designating arbitrary two points, and the brightness, chromaticity, and whiteness of all the pixels in the rectangular area B are determined. After calculating the calculated values, at least one of the maximum value, the minimum value, the average value, and the standard deviation of the calculated values may be calculated and displayed.

Returning to FIG. 4, when the procedures of steps 4 to 7 are executed for all components on the board, step 8 becomes "YES" and the image processing unit 15 determines the position of the taught component. Then, a judgment data file including the parts, the kind of the parts, the inspection area of each part, the color parameters in each inspection area, the judgment criteria, etc. is stored in the teaching table 14 to complete the teaching procedure (step 9).

Inspection data taught in steps 5 to 7 of FIG. 4 is stored in advance in a table for each component type, and at the time of teaching, the inspection data of the corresponding component type is read from the table. It is also possible to use it. Also in this case, the procedure shown in FIG. 5 is executed when setting the color parameters. When it is necessary to correct the taught color parameters, a similar procedure is executed during the correction teaching.

FIG. 8 shows steps 1 to 9 for the procedure of the automatic inspection of the mounted parts. First, steps 1 and 2 in FIG.
Then, the name of the substrate to be inspected is selected and the operation of starting the substrate inspection is performed. In the next step 3, the supply of the substrate to be inspected 1T to the mounted component inspection apparatus is checked.
If "S" is determined, the conveyor 8 is operated, the substrate 1T to be inspected is carried into the Y-axis table 4, and the automatic inspection is started (steps 4 and 5).

In step 5, the control unit 19 controls the X-axis table unit 3 and the Y-axis table unit 4 to position the field of view of the imaging unit 6 with respect to the first component 2T on the substrate 1T to be inspected, and perform imaging. Is performed, and each land area in the inspection area is automatically extracted, and the image processing unit 15 calculates a characteristic parameter of each land area to create a data file to be inspected. Next, the control section 19 causes the inspection data file to be transferred to the determination section 16 and compares the inspection data file with the determination data file to determine the mounting quality of the first component 2T such as the quality of the soldering state. Is determined.

Such an inspection is repeatedly executed for all the components 2T on the substrate 1T to be inspected, and as a result, if there is a soldering failure or the like, the defective component and the content of the failure are displayed on the display unit 20 or the printer. After being printed on 21, the substrate to be inspected 1T is carried out from the observation position (steps 7, 8). Thus, when the same inspection procedure is executed for all the substrates to be inspected 1T, the determination in step 9 is “YE
S "and the inspection is completed.

[0062]

As described above, according to the present invention , the display area of the color pattern is designated for the displayed color image.
The brightness, chromaticity, and white of the specified area
Calculate the values related to the
Color parameters required for extracting color patterns under display conditions
To accept the input of and registered. So opere
Data, specify the display area of the color pattern you want to extract.
Later, referring to the calculated value display,
The meter can be easily determined and the teaching of the color parameters
The indication can be made accurately and easily.

According to the second aspect of the present invention, the display area of an arbitrary color pattern is designated by one point, and the brightness and chromaticity of the pixel are obtained from the color image information of the pixel corresponding to the point. Since the calculated values are displayed by calculating the whiteness, the designation operation is simple, and the time required for calculation and display is reduced.

According to the third and fourth aspects of the present invention, the color to be extracted
Capability of multiple pixels included in the display area of the pattern
Color, chromaticity, and whiteness based on color image information
The minimum and maximum values, the average value, and the standard deviation
Since one is calculated and each calculated value is displayed, the color
Easy determination of optimal color parameters for turn extraction
Can be.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of a mounted component inspection apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the quality of a soldering state and a pattern.

FIG. 3 is an explanatory diagram showing a threshold table.

FIG. 4 is a flowchart showing a teaching procedure.

FIG. 5 is a flowchart showing a detailed procedure of step 7 in FIG. 4;

FIG. 6 is an explanatory diagram showing a display example of a display unit when teaching color parameters.

FIG. 7 is an explanatory diagram illustrating a display example of a display unit when teaching color parameters.

FIG. 8 is a flowchart showing a procedure of an automatic inspection.

FIG. 9 is an explanatory diagram showing a relationship between lightness, hue, and saturation.

FIG. 10 is a chromaticity diagram in which the XYZ color system is displayed in XY.

[Explanation of symbols]

 L lightness r, g, b chromaticity w whiteness 7 control processing unit 14 teaching table 19 control unit 20 display unit 22 keyboard

Continuation of the front page (72) Inventor Hideaki Takahara 24, Yamanouchi Yamanoshitamachi, Ukyo-ku, Kyoto-shi Omron Life Science Research Institute, Inc. (56) References JP-A-4-106431 (JP, A) JP-A-2- 78937 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 21/84-21/958

Claims (5)

(57) [Claims] 1. A mounting component inspecting apparatus having a function of extracting any color patterns required to test the mounting quality of a color image from the mounted component obtained by imaging the mounted components on the board, the Display means for displaying a color image, and the display
The color pattern using the color image displayed on the means.
Setting means for setting color parameters required for extracting
The setting unit is configured to extract an extraction target in the color image displayed on the display unit.
Designating means for designating a display area of a color pattern, computing means for calculating values relating to brightness, chromaticity, and whiteness with respect to the area designated by the designating means; Display on the display means
In addition, in this display state,
A mounting component inspection apparatus comprising: a control unit that receives an input of a setting value; and a registration unit that registers the setting value received by the control unit . 2. The method according to claim 1, wherein the specifying unit is a color pattern to be extracted.
Means for designating a display area of a turn by one point in the area, wherein the calculating means uses color image information about a pixel corresponding to the point designated by the designating means.
2. The mounting component inspection apparatus according to claim 1, wherein brightness, chromaticity, and whiteness of the pixel are calculated. 3. The color pattern of the extraction target
Means for designating a display area of a turn by a plurality of points in the area, wherein the calculating means uses color image information of each pixel corresponding to each point designated by the designating means.
The brightness, chromaticity, and whiteness of these pixels are calculated , and at least one of a maximum value, a minimum value, an average value, and a standard deviation is calculated for each of the calculated values of brightness, chromaticity, and whiteness. A mounting component inspection apparatus according to claim 1. 4. The color pattern of the extraction target is designated by the designation means.
Turn the display area of the turn to the area of the specified size contained in that area.
Means for designating a color image of each pixel within the area designated by the designating means.
Using the information, the brightness, chromaticity, and whiteness of these pixels are calculated , and at least one of a maximum value, a minimum value, an average value, and a standard deviation is calculated for each of the calculated values of brightness, chromaticity, and whiteness. The mounted component inspection apparatus according to claim 1, wherein: 5. The apparatus according to claim 1 , wherein said control means sets the color parameter.
Extraction of brightness, chromaticity, and whiteness as fixed values
Input of the upper and lower limits indicating the output range
A mounting component inspection apparatus according to any one of claims 1 to 4.
Place.