JPH0820229B2 - Mounting board inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a mounting board inspection apparatus for inspecting whether components are correctly mounted on a mounting board.

<< Prior Art >> As a mounting board inspection device for inspecting a mounting board created using a mounter or the like, the one shown in FIG. 12 is conventionally known.

The mounting board inspecting apparatus shown in this figure includes a TV camera 3 for picking up an image of the inspected printed board 2b on which the component 1a is mounted and the reference printed board 2a serving as an inspection reference, and the reference obtained by the TV camera 3. Image of printed circuit board 2a (reference image)
The storage unit 4 for storing the inspection print by comparing the reference image described in the storage unit 4 with the image (the inspection image) of the inspection printed circuit board 2b supplied from the TV camera 3 A determination circuit 5 for determining whether or not all the components 1b are present on the board 2b, and whether or not the components 1b are displaced or the like, and a display 6 for displaying the determination result of the determination circuit 5 are provided. It is equipped with.

<< Problems to be Solved by the Invention >> By the way, such a conventional mounting board inspecting apparatus simply arranges the position of the component 1a on the reference mounting board 2a and the position of the component 1b on the printed board 2b to be inspected. Compared with the above, when these positions are deviated, it is determined that the mounting is defective. Therefore, as shown in FIG.
The upper part 1b is the normal position 7 (the part of the standard mounting board 2a
If the position of the component 1b is deviated from the position shown in FIG. 1a), it is determined that the mounting is defective even if the electrode and the land of the component 1b are within a range in which they can be electrically connected.

Therefore, it is conceivable that an allowable range (allowable range) 8 is determined based on the regular position of the component 1b, and if the allowable range 8 is included, it is determined that the component is normally mounted. However, in this case, if the allowable range 8 is individually set for each of the components mounted on each of the mounting boards 2a and 2b, even if only the data regarding the allowable range 8 is input, it is difficult. It takes time and effort.

Further, in such a mounting board, even if the same pattern mask is used, the position of the pattern including the land formed on the board is slightly different for each board with respect to the outer shape of the board or the reference hole. Even if the component 1b is correctly placed on the land 9 on the board 2a, if this land 9 is different from the land position of the reference mounting board 2a, that is, it is input based on the reference mounting board 2a as shown in FIG. When the land position 9a and the component position 10a are deviated from the land position 9b and the component position 10b obtained by imaging the mounting board 2b to be inspected, even if the component position 10b has a correct relationship with the land position 9b. The component 1b is determined to be defective in mounting.

In view of the above problems, the present invention can automatically set the optimum positional deviation allowance for each component, and the position of the pattern including the land formed on the mounting board to be inspected is different for each board. Even if the board is different from the outer shape of the board or the reference hole, if the component is mounted within the allowable range on the land, it can be determined that the mounting is good, which results from the processing error of the board. It is an object of the present invention to provide a mounting board inspection device capable of preventing erroneous determination.

<< Means for Solving Problems >> In order to solve the above-mentioned problems, the mounting board inspection apparatus according to the present invention determines the feature amount related to the land part from each of the unmounted board image and the mounted board image obtained by the imaging means. Based on the land shape of the unmounted board and the land shape of the mounting board obtained by the land extracting means, the positional relationship between the component on the mounting board and the land is extracted. And a determination unit that determines the mounting state of the component based on the positional relationship obtained by the positional relationship extraction unit. Further, the image capturing unit is a color image capturing unit. The characteristic amount relating to the land portion is obtained by performing hue / luminance conversion from the captured image obtained by the image capturing means, and at least a red component is predetermined. A portion having an amount equal to or more than the amount is used as a characteristic amount regarding the land portion.

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

The mounting board inspection apparatus shown in FIG.
20, a lighting unit 21, an imaging unit 22, and a processing unit 23 are provided, and as shown in FIG. 1B, a land can exist from a land 28b obtained by imaging the unmounted board 25. A region (this region is wider than the land 28b) is calculated, and using this possible region, the land 28c is obtained from the image obtained by imaging the mounting board 26 to be inspected as shown in FIG. 1 (C). Is cut out, and the land 28c in this cut out portion is extracted. Then, by comparing the shapes of these lands 28b and 28c, the lands 28c on the mounting board 26 to be inspected are compared.
Then, the part hidden by the component 27c is obtained, the positional relationship between the land 28c and the component 27c is obtained from the information of the hidden portion, and it is determined whether the component 27c is correctly mounted.

The illumination unit 21 includes a ring-shaped white light source 19 that is on / off controlled (or dimming controlled) based on a control signal from the processing unit 23, and supplies an illumination on signal from the processing unit 23. When it is turned on, the upper side of the XY table 20 is illuminated until the processing unit 23 supplies an illumination off signal.

The XY table unit 20 operates in the X-axis direction and the Y-axis direction by the pulse motors 31a and 31b that operate based on the control signal from the processing unit 23 and the pulse motors 31a and 31b. -Y table 32 and this XY table
32 is provided on the XY table 32 and each substrate 24 to
A check mechanism 33 for fixing each of the substrates 24 to 26 onto the XY table 32 in response to a control signal output from the processing section 23 when the 26 is placed.
The substrates 24 to 26 fixed by 33 are imaged by the imaging unit 22 while being illuminated by the illumination unit 21.

The imaging unit 22 includes a color provided above the illumination unit 21.
A TV camera 34 is provided, and an optical image of each of the substrates 24 to 26 is converted into an electric image (R, G,
It is converted into a B color signal) and supplied to the processing unit 23.

The processing unit 23 includes an A / D conversion unit 36, a memory 37, a teaching table 38, an image processing unit 39, an XY stage controller 41, an imaging controller 42, and a CRT display 43.
, A printer 44, a keyboard 45, and a control unit (CPU) 46
And a test data file for inspecting the mounting substrate 26 to be inspected by processing the R, G and B color signals of the respective substrates 24 and 25 supplied from the image pickup section 22 at the time of teaching. To create. At the time of inspection, R, G, and B color signals of the inspected mounting board 26 supplied from the image pickup unit 22 are processed based on the inspecting data file and are formed on the inspecting mounting board 26. It is determined whether or not the relative position between the land 28c and the component 27c is within the allowable range, and this determination result is displayed.

The A / D converter 36 receives the image signal (R,
When the G and B color signals are supplied, they are A / D converted (analog / digital conversion) to create color image data, which is supplied to the control unit 46.

The memory 37 is configured by including a RAM (random access memory) and the like, and is used as a work area of the control unit 46.

When the image processing unit 39 is supplied with the image data via the control unit 46, the image processing unit 39 binarizes the image data to extract the position and shape data of the parts, and cuts out a necessary image from the image data. Alternatively, the cut-out image is subjected to hue lightness conversion, or the hue lightness conversion result is binarized by a predetermined shiki value to extract the position, shape, etc. of the land pattern. Each data obtained here is supplied to the control unit 46.

Further, the teaching table 38 is provided with a floppy disc device or the like, and when an inspection data file or the like is supplied from the controller 46, the teaching table 38 stores the teaching data file, etc.
When a transfer request is output from 46, the inspection data file or the like is read out in accordance with this request and is supplied to the control unit 46.

The imaging controller 42 includes the control unit 46 and the illumination unit.
The interface 21 and the image pickup unit 22 are connected to each other, and the illumination unit 21 and the image pickup unit 22 are controlled based on the output of the control unit 46.

The XY stage controller 41 is provided with the control unit 46.
And an interface for connecting the XY table unit 20 to each other, and controls the XY table unit 20 based on the output of the control unit 46.

The CRT display 43 is provided with a cathode ray tube (CRT) and the like, and when image data, determination results, key input data, etc. are supplied from the control unit 46, they are displayed on the screen.

Further, when the printer 44 is supplied with the judgment result or the like from the control unit 46, it prints out the judgment result or the like in a predetermined format.

Further, the keyboard 45 is provided with operation information and the mounting board to be inspected.
It is equipped with various keys necessary for inputting the name of the 26, data regarding the board size, etc., data regarding the component 27c on the mounting board 26 to be inspected, etc.
Information, data, etc. input from are supplied to the control unit 46.

The control unit 46 includes a microprocessor and the like, and operates as described below.

First, when inspecting a new mounting board 26 to be inspected,
The control unit 46 displays a message requesting the board name (for example, the board identification number) and the board size on the CRT display 43 at step ST1 of the teaching flow chart shown in FIG. 2 (A).

When the board name and board size are input from the keyboard 45, the control unit 46 proceeds to step ST2 for X-.
Wait until a teaching board (mounting board with white parts and black parts other than the parts) 24 is placed on the Y-tail 32. After this, if this board 24 is placed,
The control unit 46 controls the XY table unit 20 to arrange the first imaging area of the substrate 24 below the color TV camera 34.

Next, the control unit 46 causes the A / D conversion unit 36 to perform A / D conversion on the image signal obtained by the color TV camera 34, and stores the A / D conversion result (image data of the substrate 24) in the memory 37. Remember in real time.

Next, the control unit 46 sequentially reads out the R pixels (or G, B pixels) of the image data stored in the memory 37, binarizes them in the image processing unit 39, and paints them on the substrate 24 white. After the extracted part (part 27a part) is extracted, the position data and the shape data of each part 27a obtained by this extracting operation are stored in the teaching table 38.

After that, the control unit 46, based on the position data and the shape data of each component 27a stored in the teaching table 38 at step ST3, the component 27 as shown in FIG.
A position and shape screen 29 of a is created, and this is displayed on the CRT display device 43, and for special parts, a message requesting manual input from the keyboard 45 is displayed.

Here, if the operator inputs the position data and the shape data of the special part, the position data and the shape data of the special part stored in the teaching table 38 are corrected accordingly.

Next, in step ST4, the control unit 46 causes the CRT display 43 to display a message requesting that the type and direction of each component 27a be input, and the type and direction of each of these components 27a are input. For example, the area where the land should exist according to the shape, type, and direction of each of these parts 27a (land extraction area)
Ask for.

In this case, if the component 27a is a three-electrode component such as a transistor, a land extraction region 48a that includes each electrode 47a of the component 27a and extends outside the component 27a is obtained as shown in FIG. If the component 27a is a two-electrode component such as a resistor, the component 27a should include electrodes 47a formed at both ends of the component 27a as shown in FIG.
A land extraction area 48a is required so as to extend outside the area.

Next, the control unit 46 expands each of these land extraction regions 48b as shown in FIGS. 6A and 6B, and the land extraction region 49a thus obtained is used as the teaching table 38.
To memorize.

After this, the remaining parts 27a in this first imaging area
Also, the above-described processing is executed.

When the operation of creating the land extraction area 49a is completed for all the components 27a in the first image pickup area, the control unit 46 returns to the step ST2 via the step ST5, and the above-described processing is performed for the remaining image pickup areas. Repeatedly executed, the land extraction area for the parts 27 in all imaging areas
When 49a is obtained, the process branches from step ST5 to step ST6.

Then, in this step ST6, the control unit 46 causes the X
-Wait until the board 24 for teaching is removed from the Y table section 20 and the unmounted board 25 is placed.

Next, when the unmounted board 25 is set on the XY table section 20, the control section 46 controls the XY table section 20 to make a first image pickup of the unmounted board 25 below the color TV camera 34. Position the area.

After that, the control unit 46 A / D-converts the image signal obtained by the color TV camera 34 and stores the A / D conversion result (image data of the unmounted board 25) in the memory 37 in real time. .

Next, the control unit 46 reads the enlarged land extraction region 49a from the teaching table 38, supplies the read land extraction region 49a to the image processing unit 39, and performs image processing on the image data of the unmounted board 25 stored in the memory 37. The image data of the land extraction area 49a (the image in the land extraction area 49a) is cut out from the image data supplied to the unit 39.

Next, the control unit 46 supplies a hue / luminance conversion command to the image processing unit 39 to convert each pixel forming the image in the land extraction area into the hue / luminance.

As the hue / lightness conversion equation in this case, for example, the following equation is used.

BRT (ij) = R (ij) + G (ij) + B (ij)
(1) Rc (ij) = α · R (ij) / BRT (ij) …… (2) Gc (ij) = α · G (ij) / BRT (ij) …… (3) Bc (ij) = α · B (ij) / BRT (ij) (4) However, in this case, R (ij): R signal intensity G (ij) of the pixel (pixel (ij)) in the i-th row and the j-th column is: G signal intensity B (ij) of the pixel (pixel (ij)) in the 1st row and jth column: Pixel (B signal intensity BRT (ij): pixel of the pixel in the jth column of the i row (pixel (ij)) Brightness of (ij) α: Coefficient Rc (ij): Red phase of pixel (ij) Gc (ij): Green phase of pixel (ij) Bc (ij): Blue phase of pixel (ij) And the land extraction When the hue / luminance conversion described above is completed for all the pixels in the region 49a, the control unit 46 causes the red hue Rc (i) for each pixel (ij) in the land extraction region 49a.
j) is a land extraction reference value C (for example, C)
= 0.4 · α) or more, and the land 28b in the land extraction area 49a is extracted.

After that, the control unit 46 stores the position data and shape data regarding the land 28b in the teaching table 38, calculates the distance between the lands for each component 27a, and stores the calculation result (distance data) in the teaching table 38. Let

In this case, each of these distance data is used as data for teaching a mounter or the like the allowable error of each component 27 and designing and evaluating a land pattern.

Next, the control unit 46 expands the shape data of the land 28b to calculate the land inspection region 50b as shown in FIGS. 7 (A) and 7 (B), and stores it in the teaching table 38.

After that, the control unit 46, in step ST8, determines the component body inspection region for cutting out the central portion of each component 27a based on the position and shape of the land 28b, as shown in FIGS. 8 (A) and (B). Calculate 51b and use this for teaching table 3
A message requesting characteristic data (for example, color data) relating to the body of each component 27a is displayed on the CRT display 43 while being stored in the memory 8.

Then, the operator operates the keyboard 45, and all parts 27
When the characteristic data of a is input, the control unit 46 stores it in the teaching table 38.

After this, the remaining parts 27a in this first imaging area
Again, the above operation is repeated.

When the land extraction process to the feature data input process have been completed for all of the components 27a in the first imaging area, the control unit 46 proceeds to step S9 through step ST9.
Returning to T6, the above-described processing is repeatedly executed for the remaining imaging area.

After that, when the above-described processing is completed for the parts 27a in all the imaging areas, the control unit 46 branches from step ST9 to step ST10.

Then, in this step ST10, the control unit 46 organizes each data stored in the teaching table 38 to create an inspection data file, stores the inspection data file in the teaching table 38, and ends the teaching operation.

When the teaching operation is completed and the inspection mode is entered, the control unit 46 sets the inspected mounting substrate 2 on the CRT display 43 at step ST11 of the inspection flow chart shown in the second (B).
Display a message requesting the board name of 6.

When the board name is input from the keyboard 45, the control unit 46 waits in step ST12 until the mounting board 26 to be inspected is placed on the XY table 32. After this, when the mounting board 26 to be inspected is placed, the control section 46 controls the XY table section 20 to arrange the first imaging area of the mounting board 26 to be inspected below the color TV camera 34.

Next, the control unit 46 causes the A / D conversion unit 36 to perform A / D conversion on the image signal obtained by the color TV camera 34, and at the same time, outputs the A / D conversion result (image data of the mounting board 26 to be inspected). Store in memory 37 in real time.

Next, the control unit 46 reads the component body inspection area 51b from the teaching table 38, and reads it out from the image processing unit 3
9, while supplying the image data of the mounting substrate 26 to be inspected stored in the memory 37 to the image processing unit 39,
An image of the inspection area 51b is cut out from this image data.

Next, the control unit 46 supplies a feature extraction command to the image processing unit 39 to extract the feature data of the image cut out by the inspection area 51b (for example, each pixel of the image is converted into hue and lightness).

Thereafter, the control unit 46, in step ST13, the inspection area 51.
The feature data of the image in b is displayed in the teaching table 38.
It is determined whether or not they match the feature data of each part 27a stored in, and if they match, the process branches from this step ST13 to step ST14, where the teaching table 38 to the land inspection area 50b. Is read out and supplied to the image processing unit 39, and the memory 37
The image data of the mounting substrate 26 to be inspected stored in is supplied to the image processing section 39, and the image of the land inspection region 50b is cut out from this image data.

Next, the control unit 46 supplies a hue / luminance conversion command to the image processing unit 39 to convert the respective pixels forming the image of the land inspection region 50b into the dye lightness.

When the hue and brightness conversion described above is completed for all the pixels in the land inspection area 50b, the control unit 46 determines in step ST15 the red hue Rc (ij) for each pixel (ij) in the land inspection area 50b in advance. The land 28c in the land inspection region 50b is extracted by checking whether or not the input land extraction reference value C (for example, C = 0.4 · α) or more.

After that, the control unit 46 controls each pixel (i
The electrode 47c in the land inspection region 50b is extracted by checking whether or not BRT (ij) for j) is equal to or greater than the electrode extraction reference value D input in advance.

Then, the control unit 46 proceeds to step ST16 and inspects the land inspection area 50.
The position of the electrode electrode 47c in the b, the shape of the land 28c with reference to the shape, and the shape of the land 28b of the unmounted board 25 described in the teaching table 38 are compared, and the component 27c of the land 28c is compared. Calculate the part hidden by (estimate)
To do.

After that, the control unit 46, at step ST17, calculates these lands 28c from these calculation results as shown in FIGS. 9 (A) and 9 (B).
Cover area data indicating the positional relationship with the part 27c (Land 2
Area data of the part hidden by the part 27c of 8c), width data, and depth data are obtained, and it is checked whether the values of these data are sufficient.

Then, if each of these values is sufficient, the control unit 46 branches from this step ST17 to step ST18, and here it is determined that this component 27c is mounted well, and this is displayed on the CRT display 43. Is displayed or is printed out from the printer 44.

Further, in each of the steps ST13 and ST17, the inspection area 51
The feature data of the image in b is displayed in the teaching table 38.
If it is determined that they do not match the feature data of each component 27a stored in, or if it is determined that the fog area data, the width data, and the depth data indicating the positional relationship between the land 28c and the component 27c are not sufficient. The control unit 46 branches from each of these steps ST13 and ST17 to step ST19, where it determines that this component 27c is improperly mounted and displays it on the CRT display 43 or prints it from the printer 44. To go out.

After this, the remaining parts 27c in the first imaging area
On the other hand, when the above-described processing is repeated and the determination processing is completed for all the components 27c, the control unit 46 proceeds to step ST.
The process returns to step ST12 via 20 and the above-described processing is repeatedly executed for the remaining imaging area.

Then, when the determination process is completed for the components 27c in all the imaging areas, this inspection process is completed.

Thus, in this embodiment, the mounting substrate 26 to be inspected is
Even if the land 28c is different for each board, if the component 27c is mounted within the allowable range on the land 28c, it can be determined that the mounting is good. It is possible to prevent each part
It is possible to automatically set the optimum positional deviation allowance for 27c.

As a result, in the cases shown in FIGS. 10 (A), (B) and FIGS. 11 (A), (B), it is judged that the mounting is good, and also in FIGS. 10 (C) and 11 In the cases shown in (C) and (D), it can be determined that the mounting is defective.

Further, in the above-described embodiment, the type of the component 27a is manually input at the time of teaching, but the component 27a is input from the image input using the reference mounting board or the like.
The electrode of a may be detected, and the type of the component 27a may be automatically input from this electrode position.

Further, in the above-described embodiment, the characteristic data of the component 27a is manually input at the time of teaching, but it may be automatically input by using the reference mounting board or the like.

<< Advantages of the Invention >> As described above, according to the present invention, it is necessary to individually set the permissible range of component misalignment for each component mounted on the mounting board as in the related art. The optimum amount of misalignment allowance can be automatically set for each component, and even if the position of the land on the board to be inspected is slightly different for each board with respect to the reference hole, etc. If the components are mounted within the allowable range of, it can be determined that the mounting is good, and thus it is possible to prevent erroneous determination due to the processing error of the board, and It is possible to know the shape and the like of the portion hidden by the formed parts.

[Brief description of drawings]

FIG. 1 (A) is a block diagram showing an embodiment of a mounting board inspection apparatus according to the present invention, and FIG. 1 (B) is a diagram schematically showing an image pickup result of an unmounted board in the embodiment, FIG. FIG. 2C is a diagram schematically showing the imaging result of the mounting board to be inspected in the embodiment, FIG. 2A is a flow chart showing a teaching operation example of the embodiment, and FIG.
Is a flow chart showing an example of the inspection operation of the embodiment, FIG. 3 is a schematic view showing an example of the position and shape screen of the parts of the embodiment, and FIG. 4 is an example of a land extraction region for the transistor etc. of the embodiment. FIG. 5 is a schematic diagram showing an example of a land extraction region for resistance and the like of the same embodiment, and FIGS. 6A and 6B are enlarged land extractions for respective parts of the same embodiment. 7A and 7B are schematic diagrams showing an example of a region, FIG. 7A and FIG. 7B are schematic diagrams showing an example of a land inspection region for each component of the same embodiment, and FIGS. 8A and 8B are the same. 9A and 9B are schematic views showing an example of a component body inspection region for each component of the embodiment, and FIGS. 9A and 9B are schematic diagrams for explaining a determination operation for the positional relationship between the component and the land in the embodiment. FIG. 10 and FIGS. 10 (A) to 10 (C) each illustrate a determination example of the same embodiment. 11A to 11D are schematic diagrams for explaining the determination example of the same embodiment, and FIG. 12 is a block diagram showing an example of a conventional mounting board inspection device, and FIG. FIG. 14 is a schematic diagram for explaining a mounting deviation in this mounting board inspection device, and FIG. 14 is a schematic diagram showing a positional relationship between lands and components in this mounting board inspection device. 22 …… Imaging means (imaging section), 25 …… Unmounted board, 26 ……
Mounting board, 27c ... Component, 28b, 28c ... Land, 39 ... Land extracting means (image processing section), 46 ... Positional relationship extracting means, determination means (control section).

Claims (2)

[Claims] 1. A land extracting unit that extracts a land portion based on a feature amount related to a land portion from each of the unmounted board image and the mounted board image obtained by the image pickup unit, and the unmounted board obtained by the land extracting unit. A positional relationship extracting means for extracting a positional relationship between a component on the mounting board and the land based on the land shape of the board and the land shape of the mounting board, and mounting of the component from the positional relationship obtained by the positional relationship extracting means. A mounting board inspection apparatus comprising: a determination unit that determines a state. 2. The image pickup means is a color image pickup means, and the characteristic quantity relating to the land portion is obtained by performing hue / luminance conversion from a picked-up image obtained by the image pickup means, and at least a red color component is a predetermined amount. The mounting board inspection device according to claim 1, wherein the above-mentioned portion is a characteristic amount regarding a land portion.