JPH0835826A - Substrate tester - Google Patents

Abstract

PURPOSE:To enable the judging of the quality of a mount of a part by extracting an electrode area and a land part formed on a substrate automatically. CONSTITUTION:A substrate 25 with no parts mounted and a substrate 26 with parts on are fixed on an X-Y table 32 and photographed with a color TV camera 34 of an image pickup section 22 being lighted with a lighting section 21. A processing section 23 determines pixels to be those of a copper foil parts(parts of lands 28b and 28c) when values of red hues of the pixels obtained exceed values determined previously. The relative positional relationship is determined between the land 28c and a part 27c based on the results of the judgment to judge the quality of a mount of the part 27c. In other words, the processing section 23 extracts an electrode area from image information concerning an electrode of the part 27c stored previously and a land part from the pixels. Then, a color signal of the mounted substrate 26 to be inspected is processed to judge whether the relative position between the land 28c and the part 27c formed on the substrate 26 is within an allowable range or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board inspection device for inspecting the mounting quality of a component mounted on a board.

[0002]

2. Description of the Related Art As a mounting board inspection apparatus for inspecting the mounting quality of components on a mounting board prepared by using a mounter or the like, a mounting board inspection apparatus shown in FIG. 12 is conventionally known.

The mounting board inspecting apparatus shown in this figure has a component 1
a TV camera 3 for capturing an image of the mounting board 2b on which the b is mounted and the reference mounting board 2a serving as an inspection reference, and a storage for storing an image (reference image) of the reference mounting board 2a obtained by the TV camera 3 Unit 4 and a reference image stored in the storage unit 4 and an image (inspection image) of the inspection mounting substrate 2b supplied from the TV camera 3 to compare the reference image on the inspection mounting substrate 2b. A determination circuit 5 for determining whether all the parts 1b are present and whether or not these parts 1b are displaced or the like are provided, and a display 6 for displaying a determination result of the determination circuit 5 is provided. ing.

[0004]

However, in such a conventional mounting board inspection apparatus, the position of the component 1a on the reference mounting board 2a and the component 1b on the mounting board 2b to be inspected are known.
Are simply compared with each other, and when these positions deviate, it is determined that the mounting is defective. Therefore, as shown in FIG. 13, the component 1b on the mounting board 2b to be inspected is
Is shifted from the normal position 7 (the component position indicated by the component 1a of the reference mounting board 2a),
Even if the electrode and the land 9 are within a range where they can be electrically connected, it is determined that the mounting is defective.

Therefore, an allowable range (allowable range) 8 is determined based on the regular position of the component 1b, and if it is within the allowable range 8, it may be determined that the mount is normally performed. 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, in this case, even if the data regarding the allowable range 8 is input, It requires a lot of work and effort.

In such a mounting board, even if the same pattern mask is used, the pattern formed on the board is slightly different for each board, so that the component 1b is correctly mounted on the land 9 on the mounting board 2a. However, if the land 9 is different from the land position of the reference mounting board 2a, that is, as shown in FIG. 14, the land position 9a, the component position 10a input based on the reference mounting board 2a, and the If the land position 9b and the component position 10b obtained by capturing the image of the component 2b deviate from each other, even if the component position 10b is in a correct relationship with the land position 9b, it is determined that the component 1b is defective in mounting. .

In view of the above problems, the present invention automatically determines the electrode area and the land portion formed on the substrate, so that it is possible to determine the mounting quality of the component based on the electrode area and the land portion. It is an object of the present invention to provide a substrate inspection apparatus that has

[0008]

In order to solve the above problems, a board inspection apparatus according to the present invention relates to a position, a direction, a kind, and a land portion of each of the parts, which are stored in advance on an unmounted board. A component and land storage means for storing data, a storage means for calculating and storing a location of a land portion from the component and land storage means, an image pickup means for picking up an image of a component mounting board to be inspected, and an image picked up by the image pickup means. Land part extraction means for extracting the land part of each part of the storage means from the captured image, electrode storage means for storing image information regarding the electrode of the part in advance, and the electrode from the extracted image extracted by the land part extraction means. The component part is mounted by the electrode region extracted using the image information stored in the storage means and the land part extracted by the land part extraction means. It is characterized by comprising determination means for determining bets quality, a.

[0009]

The electrode region and land portion formed on the substrate are automatically extracted to judge the quality of the component mounting.

[0010]

FIG. 1 is a block diagram showing an embodiment of a substrate inspection apparatus according to the present invention.

The board inspection apparatus shown in FIG. 1 includes an XY table section 20, an illumination section 21, an imaging section 22, a processing section 2
3 and the unmounted board 25 and the board 2 to be inspected.
Each pixel of the image obtained by imaging 6 is converted into hue and brightness,
When the value of the red phase of each pixel obtained as described above is equal to or greater than a predetermined value, this pixel is placed in a copper foil portion (land 2).
8b and 28c portions). Then, based on the determination result, the relative positional relationship between the land 28c and the component 27c is obtained, and the quality of the mounting of the component 27c is determined.

The illumination unit 21 includes a ring-shaped white light source 19 which is on / off controlled (or dimming controlled) based on a control signal from the processing unit 23. The light is turned on when a signal is supplied, and the light is turned off when the lighting off signal is supplied from the processing unit 23.
-Illuminates the upper surface side of the Y table portion 20.

The XY table section 20 includes the processing section 23
Pulse motor 31 that operates based on the control signal from
a, 31b, an XY table 32 driven by the respective pulse motors 31a, 31b in the X-axis direction and the Y-axis direction, provided on the XY table 32, and provided on the XY table 32. A chuck mechanism 33 for fixing the substrates 24 to 26 on the XY table 32 in accordance with a control signal output from the processing unit 23 when the substrates 24 to 26 are placed; Mechanism 3
Each of the substrates 24 to 26 fixed by the
The image is captured by the image capturing unit 22 while being illuminated by 1.

The imaging unit 22 includes a color TV camera 34 provided above the illumination unit 21. The optical images of the substrates 24 to 26 are converted into electric images (R, G, B signal is supplied to the processing unit 23.

The processing unit 23 includes an A / D conversion unit 36, a memory 37, a teaching table 38, and an image processing unit 3.
9, an XY stage controller 41, an imaging controller 42, a CRT display 43, a printer 44,
A keyboard 45 and a control unit (CPU) 46 are provided. At the time of teaching, R, G, and B color signals of each of the substrates 24 and 25 supplied from the imaging unit 22 are processed and mounted on a board for inspection. An inspection data file for inspecting the substrate 26 is created. At the time of inspection, R, G, and B color signals of the inspected mounting board 26 supplied from the imaging unit 22 are processed based on the inspection data file, and are formed on the inspected 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.

When the image signals (R, G, B color signals) are supplied from the image pickup unit 22, the A / D conversion unit 36 performs A / D conversion (analog / digital conversion) on the image signals to convert them into color signals. Image data is created and supplied to the control unit 46.

The memory 37 includes 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 the necessary data from the image data. The image is cut out, the hue and brightness of the cut out image are converted, and the result of the hue and brightness conversion is binarized by a predetermined threshold to extract the position, shape, etc. of the land pattern. Cage,
The respective data obtained here are supplied to the control unit 46.

The teaching table 38 is provided with a floppy disk device and the like. When a test data file or the like is supplied from the control unit 46, it is stored and a transfer request is output from the control unit 46. At this time, an inspection data file or the like is read in response to the request, and the read data file is supplied to the control unit 46.

The imaging controller 42 includes the control unit 46
And an interface for connecting the illumination unit 21 and the imaging unit 22, and controls the illumination unit 21 and the imaging unit 22 based on the output of the control unit 46.

The XY stage controller 41 includes:
The control unit 46 includes an interface for connecting the XY table unit 20 and the like, and controls the XY table unit 20 based on the output of the control unit 46.

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

When the printer 44 is supplied with the judgment result and the like from the control section 46, it prints out the judgment result in a predetermined format.

The keyboard 45 is used for inputting operation information, data on the name of the board 26 to be inspected, board size, etc., and data on the components 27c on the board 26 to be inspected. Keys are provided, and information, data, and the like input from the keyboard 45 are supplied to the control unit 46.

The control section 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 section 46 executes the CRT display 43 in step ST1 of the teaching flowchart shown in FIG.
A message requesting a board name (for example, a board identification number) and a board size is displayed above.

When the board name and the board size are input from the keyboard 45, the control unit 46 displays a board for teaching (the part 27a is white and the other parts are white on the XY table 32) in step ST2. Wait until the mounting board 24 whose part is painted black) is mounted. Thereafter, when the substrate 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 controls the color TV camera 3
The A / D converter 36 converts the image signal obtained by
Along with D conversion, this A / D conversion result (the substrate 24
Image data) is stored in the memory 37 in real time.

Next, the control section 46 sequentially reads out the R pixels (or G and B pixels) of the image data stored in the memory 37, binarizes them by an image processing section 39, and Part painted white (part 27
After extracting the part (a), the position data and the shape data of each part 27a obtained by this extraction operation are stored in the teaching table 38.

Thereafter, the control unit 46 determines the position and shape screen of the part 27a as shown in FIG. 3 based on the position data of each part 27a stored in the teaching table 38 and the shape data in step ST3. Create 29,
This is displayed on the CRT display 43, and a message requesting manual input from the keyboard 45 is displayed for special parts.

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, the control unit 46 sets C in step ST4.
A message requesting the user to input the type and direction of each component 27a is displayed on the RT display 43. When the type and direction of each component 27a are input, the shape and shape of each component 27a are displayed. An area where a land should exist (land extraction area) is determined according to the type and direction.

In this case, if the component 27a is a three-electrode component such as a transistor, a land extraction region 48a including the electrodes 47a of the component 27a and extending outside the component 27a as shown in FIG. If the component 27a is a two-electrode component such as a resistor, etc., FIG.
The land extraction region 48a is required to include the electrodes 47a formed at both ends of the component 27a and spread outside the component 27a as shown in FIG.

Next, the control unit 46 controls the operation shown in FIG.
As shown in (B), each of these land extraction areas 48a is expanded, and the land extraction areas 49a obtained thereby are stored in the teaching table 38.

After that, the above-mentioned processing is executed also for the parts 27a remaining in the first image pickup area.

Then, the component 27 in the first imaging area
When the operation of creating the land extraction areas 49a for all a is completed, the control unit 46 returns to step ST2 via step ST5, repeatedly executes the above-described processing for the remaining imaging areas, and 27
When the land extraction area 49a is obtained for a, the process branches from step ST5 to step ST6.

In step ST6, the control unit 46 waits until the teaching board 24 is removed from the XY table 2c 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 place the unmounted board 25 below the color TV camera 34. Position the first imaging area.

Thereafter, the control unit 46 controls the color TV camera 3
A / D conversion is performed on the image signal obtained in step 4 and the result of the A / D conversion (image data of the unmounted board 25) is stored in the memory 37 in real time.

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

Next, the control unit 46 controls the image processing unit 3
A hue / luminance conversion command is supplied to 9 to convert each pixel forming the image in the land extraction area 49a into 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): the j-th column of the i-th row R signal intensity of the pixel (pixel (ij)) in G (ij): the pixel (pixel (i
j)) G signal intensity B (ij): pixel (pixel (i
j)) B signal intensity BRT (ij): Brightness of pixel (ij) α: Coefficient Rc (ij): Red phase of pixel (ij) Gc (ij): Green phase of pixel (ij) Bc (ij) : Blue hue of pixel (ij) Then, when the hue / luminance conversion described above is completed for all the pixels in the land extraction area 49a, the control unit 46
Calls the land extraction routine shown in FIG. 2B in step ST7, and 1 in step ST25 of this routine.
The red color Rc (ij) for one pixel (ij) is extracted. Thereafter, the control unit 46 determines the land extraction reference value C (for example, C =
0.4.d) or more, and Rc (ij)
If> C, this red phase Rc (i) is determined in step ST27.
The pixel (ij) corresponding to j) is determined to be the pixel of the copper foil portion. If Rc (ij) ≦ C, the control unit 46
In step ST28, the pixel (ij) corresponding to the red phase Rc (ij) is determined to be a pixel other than the copper foil portion.

When the copper foil / non-copper foil determination processing is completed for all pixels in the land extraction area 49a, the control unit 46
Branches to step ST30 via step ST29, where the position data and shape data of the land 28b are calculated (extracted) by integrating the portions determined to be pixels of the copper foil portion, and then the original Return to flow.

After that, the control unit 46 stores the position data and shape data regarding the land 28b in the teaching table 38 in step ST8 of this flow, and
The distance between lands for each component 27a is calculated, and the calculation result (distance data) is stored in the teaching table 38.

In this case, these distance data are used as data for instructing the mounter on the tolerance of each component 27 and for evaluating the design of the land pattern.

Next, in step ST9, the control section 46 expands the shape data of the land 28b as shown in FIGS. 7A and 7B, calculates a land inspection area 50b, and stores it in the teaching table 38. Let it.

Thereafter, the control unit 46 proceeds to step ST10.
8 based on the position and shape of the land 28b.
As shown in (A) and (B), a component body inspection area 51b for cutting out a central portion of each component 27a is calculated,
This is stored in the teaching table 38, and a message requesting feature data (for example, color data) relating to the body of each component 27a is displayed on the CRT display 43.

When the operator operates the keyboard 45 to input the characteristic data of all the parts 27a, the control unit 4
6 stores this in the teaching table 38.

Thereafter, the control unit 46 returns to step ST6 via step ST11, and repeatedly executes the above-described land extraction processing and the input processing of the characteristic data for the remaining imaging areas.

Thereafter, when the above-described processing is completed for the components 27a in all the imaging areas, the control unit 46 branches from step ST11 to step ST12.

Then, in this step ST12,
The control unit 46 arranges each data stored in the teaching table 38 to create an inspection data file, stores it in the teaching table 38, and ends the teaching operation.

When the teaching operation is completed and the inspection mode is set, the control unit 46 sets the CRT display 4 in step ST13 of the inspection flowchart shown in FIG.
A message requesting the board name of the mounting board 26 to be inspected is displayed on 3.

Then, if this board name is input from the keyboard 45, the control section 46 performs X- in step ST14.
Wait until the mounting board 26 to be inspected is placed on the Y 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 controls the color TV camera 3
The A / D converter 36 converts the image signal obtained by
The D / D conversion is performed, and the result of the A / D conversion (image data of the board 26 to be inspected) is stored in the memory 37 in real time.

Next, the control unit 46 reads the component body inspection area 51b from the teaching table 38,
This is supplied to the image processing unit 39, and the memory 37
Is supplied to the image processing unit 39, and an image of the inspection area 51b is cut out from the image data.

Next, the control unit 46 controls the image processing unit 3
9, a feature extraction command is supplied to extract feature data of an image cut out by the component body inspection area 51b (for example, each pixel of the image is converted into hue and brightness).

Thereafter, the control section 46 proceeds to step ST15.
It is determined whether the feature data of the image in the component body inspection area 51b matches the feature data of each component 27a stored in the teaching table 38, and if they match, this step is performed. ST1
5 branches to step ST16, where the land inspection area 50b is read from the teaching table 38,
This is 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.

Then, the control unit 46 controls the image processing unit 3
9 is supplied with a hue / lightness conversion command to convert the pixels constituting the image of the land inspection area 50b into hue / lightness.

When the above-described hue / lightness conversion is completed for all the pixels in the land inspection area 50b, the control unit 46 proceeds to step ST17 where the red hue Rc (ij) for each pixel (ij) in the land inspection area 50b is determined. ) Is a land extraction reference value C (for example, C = 0.4 ·
α) is checked, and the land inspection area 50 is checked.
The land 28c in b is extracted.

Thereafter, the control unit 46 determines in step ST18 the BR for each pixel (ij) in the land inspection area 50b.
It is checked whether or not T (ij) is equal to or greater than a previously input electrode extraction reference value D, and an electrode 47c in the land inspection area 50b is extracted.

Next, in step ST 19, the control unit 46 refers to the position and the shape of the electrode 47 c in the land inspection area 50 b and the shape of the land 28 c and the shape of the unmounted board 25 stored in the teaching table 38. Compare the shape of the land 28b with the part 27c of the land 28c.
Calculate (estimate) the part hidden by.

Thereafter, the control unit 46 calculates the fogging area data (shown by the part 27c of the land 28c) indicating the positional relationship between the land 28c and the part 27c as shown in FIGS. Area data), width data, and depth data are obtained, and it is checked in step ST20 whether the values of these data are sufficient.

If these values are sufficient, the control unit 46 proceeds from step ST20 to step ST21.
Then, it is determined that the component 27c is mounted well, and the component 27c is displayed on the CRT display 43 or printed out from the printer 44.

In each of the steps ST15 and ST20, it is determined that the feature data of the image in the component body inspection area 51b does not match the feature data of each component 27a stored in the teaching table 38, If it is determined that the fogging area data, the width data, and the depth data indicating the positional relationship between the component 28c and the component 27c are not sufficient, the control unit 46 performs these steps ST
15. The process branches from ST20 to step ST22, where it is determined that the component 27c is defective in mounting, and the CR 27 is determined.
This is displayed on the T display 43 or printed out from the printer 44.

Thereafter, the control unit 46 returns to step ST14 via step ST23, and repeatedly executes the above-described processing on the remaining imaging areas.

When the determination process is completed for the parts 27c in all the imaging areas, this inspection process is completed.

As described above, in this embodiment, the lands 28b and 28c can be extracted. Thereby, even if the land 28c of the mounting board 26 to be inspected differs for each board, if the component 27c is mounted within an allowable range on the land 28c, it can be determined that the mounting is good. In addition, it is possible to prevent erroneous determination due to a processing error of the board, and to automatically set an optimum positional deviation allowable amount for each component 27c.

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

In the above-described embodiment, the type of the component 27a is manually input at the time of teaching. However, the electrode of the component 27a is detected from an image input using a reference mounting board or the like. From this electrode position, part 2
The type of 7a may be automatically input.

In the above-described embodiment, the hue / lightness conversion of the image is performed by the image processing unit 39. However, the output of the image pickup unit 22 is analog-processed, and the hue / lightness is controlled by the program processing of the control unit 46. Conversion may be performed.

In the above-described embodiment, the feature data of the component 27a is manually input at the time of teaching. However, the feature data may be automatically input using a reference mounting board or the like. good.

[0073]

As described above, according to the present invention, it is possible to automatically extract the electrode area and the land portion formed on the substrate, and thereby, it is possible to mount the component by the electrode area and the land portion. Can be determined.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a substrate inspection apparatus according to the present invention.

FIG. 2A is a flowchart illustrating an example of a teaching operation of the embodiment. (B) is a flowchart of a land extraction routine of the same embodiment. (C) is a flowchart showing an example of the inspection operation of the embodiment.

FIG. 3 is a schematic diagram showing an example of a position / shape screen of a part of the embodiment.

FIG. 4 is a schematic diagram showing an example of a land extraction region for a transistor and the like according to the embodiment.

FIG. 5 is a schematic diagram showing an example of a land extraction region for a resistor and the like in the embodiment.

6A and 6B are schematic diagrams showing an example of an enlarged land extraction area for each component of the embodiment.

FIGS. 7A and 7B are schematic diagrams each showing an example of a land inspection area for each component of the embodiment.

FIGS. 8A and 8B are schematic views showing an example of a component body inspection region for each component of the embodiment.

FIGS. 9A and 9B are schematic diagrams for explaining a determination operation for a positional relationship between a component and a land in the embodiment.

FIGS. 10A to 10C are schematic diagrams for explaining a determination example of the embodiment.

FIGS. 11A to 11D are schematic diagrams for explaining a determination example of the same embodiment.

FIG. 12 is a block diagram illustrating an example of a conventional mounting board inspection apparatus.

FIG. 13 is a schematic diagram for explaining a mount shift in the mounting board inspection apparatus.

FIG. 14 is a schematic diagram showing a positional relationship between lands and components in the board inspection apparatus.

[Explanation of symbols]

 22 image pickup unit 25 unmounted board 26 inspected mounted board 27c parts 28b, 28c land 39 hue conversion unit (image processing unit) 46 determination unit (control unit)

─────────────────────────────────────────────────── ───Continued from the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H05K 13/08 D 8315-4E

Claims (1)

[Claims] 1. A component and land storage means for storing data on a position, a direction, a type, and a land portion of each component stored in advance on an unmounted board, and a land portion from the component and land storage means. Storage means for calculating and storing a place; image pickup means for picking up an image of the component mounting board to be inspected; and land part extraction means for extracting land parts of each part of the storage means from an image picked up by the image pickup means An electrode storage unit that stores image information about the electrodes of the parts in advance; an electrode region and the land region extraction unit that are extracted from the extracted image extracted by the land region extraction unit using the image stored in the electrode storage unit; A mounting board inspection apparatus comprising: a determination unit that determines whether the mount of the component is good or bad based on the land portion extracted by .