JPH0493755A - Inspecting apparatus for printed wiring board - Google Patents

Abstract

PURPOSE:To make it possible to prevent false information from the surrounding part of a through hole by providing a mask memory part having a through-hole- basic-mask forming part and a defect detecting part having a through-hole-mask correcting part. CONSTITUTION:A mask part 2 comprises a through-hole-basic-mask forming part, which extracts only the hole part of the through hole of a wiring board 10 and arbitrarily expands and contracts the image of the extracted hole, and a through-hole-mask memory part 22 for holding the forming part 21. A defect detecting part 3 comprising a defect-shape recognizing part 31, a through-hole- mask correcting part 35 and a through-hole-mask collating part 36 is used as a defect detecting system for wire breakdown. In addition, there are a chipped-defect detecting part 3B, a short-defect detecting part 3C and a defect detecting part for detective part between lines 3D. The through hole mask is individually collated with the defect candidate data at the optimum position and the size. Thus, the false information from the surrounding part of the through hole can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inspection device for detecting defect shapes in wiring patterns on printed wiring boards, and particularly to an inspection device for preventing false alarms from around through holes. .

[Prior Art] During the manufacturing process of a wiring pattern on a printed wiring board, defects such as disconnection, chipping (line thinning), short circuit, poor line spacing, and dust adhesion may occur. Therefore, various inspection devices for detecting such defect shapes have been proposed.

On the other hand, as shown in FIG. 13, the printed wiring board 10 has through holes 90 and wiring patterns 9. The wiring pattern 9 consists of a land 91 formed in an annular shape around the opening of the through hole 90 and a line pattern 92 connecting one circuit terminal (path shown). The wiring pattern 9 is formed of a metal plating layer.

Generally, the convergence of the land 91 (for example, about 50 μm)
) is the width of the line pattern 92 (for example, about 150 μm)
It is formed narrower than the Therefore, as shown in FIG. 14, when the land 91 is formed slightly off from the axial center of the through hole 90, two narrow portions 911 and two wide portions 912 are formed. In addition, the narrow portion 911
This also occurs due to a small remaining seat width due to poor etching. Therefore, when the land portion is inspected by the inspection device, inspection data 94 as shown in FIG. 15 is detected. In this inspection data 94,
The narrow width portion 911 of the land 91 is considerably narrower than the width of the line pattern 92, and the line pattern 92 is recognized as having a defective shape. Therefore, the narrow portion 911 is detected as being in a chipped (thinned) state 941.

However, as shown in FIG. 14, the narrow portion 911 is
There is no disconnection and there is no practical problem.

In this way, false information is likely to occur in the inspection data obtained by the conventional inspection apparatus. Such false alarms are particularly common regarding the land 91 formed around the through hole.

In order to deal with the above-mentioned problem, there is an inspection apparatus that performs mask processing on the through-hole portion and does not inspect the area around the through-hole when inspecting a line pattern, thereby eliminating erroneous determinations around the through-hole.

As shown in FIG. 16, the inspection device includes a CCD camera 11 that reads the wiring pattern 101 on the printed wiring board 10, and an A/D converter 12 that converts the analog signal of the CCD camera 11 into a digital image signal. , a mask section 81, a defect shape recognition section 851, and a through hole for comparing signals from the mask section 81 and the defect shape recognition section.
It consists of a mask matching section 841, a data summation section 15 that sums up the matching results, and a terminal 16 as a display means.

The mask section 81 includes a through-hole mask creating section 811 that forms a through-hole mask based on a binary image signal from the A/D converter 12, and a through-hole mask making section 811 that forms a through-hole mask based on the wiring pattern of a printed wiring board based on the 7 standard. It consists of a memory part 812 that stores the hole mask, and a readout part 813 that reads the through-hole mask during inspection.

The creation of the through-hole mask in the above-mentioned through-hole mask creation section was done before the wiring pattern was formed. It is created by imaging the area around the through-hole using a printed wiring board that does not cause any breakage on the binary image.

By doing this, the positional relationship between the through-hole and the land is recognized, and a mask of sufficient size is created so that no false alarms appear in any detection system during actual inspection. The above-mentioned detection system refers to a system (corresponding to the defect shape recognition units 851, 852, and 853 in FIG. 16) that performs detection corresponding to each defect shape such as disconnection, chipping, and short circuit in the line pattern.

Further, in the readout section 813, correction is made at the time of readout so that the through-hole mask is applied to the middle of the defect shape recognition positions of all the detection systems.

Next, the defect shape recognition unit 851 processes the image signal from the A/D converter l2 using a spatial filter, and recognizes (detects) the defect shape related to the wire breakage using a feature extraction method.

In addition, in the same figure, other defect shape recognition parts 852 and 853
Similarly, the image signal is processed by a spatial filter, and
Recognize defect shapes related to chips and shorts, respectively.

The above spatial filters are each designed to pass only image signals corresponding to the shape of the defect, such as for wire breakage or short circuit. In addition, this defect shape recognition unit is
If the binary image signal from the D converter 12 is data (defect candidate data) that is tentatively determined to be a defect shape, the defect candidate data is sent to the through-hole mask matching section.

Further, the through-hole mask matching section 841 matches the defect candidate data from the defect shape recognition section 851 and the through-hole mask from the reading section 813 of the mask section 81. At this time, the above-mentioned reading of the through-hole mask is corrected so that the through-hole mask is placed at the center of the matrix of the defect shape recognition spatial filter, which is the average of the defect candidate data related to the disconnection of the defect shape recognition unit 851. Do this by applying

As a result of the above-mentioned comparison in the 2 through-hole mask comparison section 841, when it is determined that the defect candidate data is a true defect shape, a signal to that effect is sent to the data aggregation section 15. It is sent to terminal 16. That is, if the defect candidate data is not inside the through-hole mask, it is recognized as a true defect shape.

These operations are also performed between the defect shape recognition units 852 and 853 and the through-hole mask verification units 842 and 843, and defect shapes such as chips and shorts are inspected.

[Problem to be solved]

However, since the defect shape recognition unit detects defect candidate data using a method of extracting features using a spatial filter, rules for feature extraction are set within the window of the spatial filter. For this reason, it is not always possible to set rules so that the defective part fits in the center of the window.

On the other hand, a through-hole mask is created around the hole, so when the spatial filter rules for defect shape recognition are matched around the through-hole, the mask is placed at the position corresponding to the hole. This can be said to be the correct way to apply a mask.

FIG. 17 shows the hole portion 960 located within the window 96 of the spatial filter.

In the figure, the missing parts indicate the states. That is, in this case, there is an image signal of the pattern image 962 of the wiring pattern and an image signal of the base material image 961 of the printed wiring board, and a hole portion 960 that is assumed to be a hole is located, but the hole portion 960 is located in the window. at any position. That is, the hole portion 960 is not in the center position.

On the other hand, in FIG. 2, there is a pattern image 972 and a base material image 971, and the position assumed to be the hole is a point shown at 970. Note that this figure shows a case where the wire is disconnected.

Both of these figures show that when rules are set for windows of the same size, the position of one hole is arbitrary.

As described above, since the positions of the holes in the window are different, even if a uniform through-hole mask is sent from the readout section 8]3 of the mask section to the through-hole mask matching section 841, the matching accuracy will be low. bad. In other words, even though the defect candidate data is not a true defect shape, the through-hole mask comparison unit will issue a false report as a true defect shape.

Therefore, in order to prevent the above-mentioned false alarm, it is conceivable to send the data of the thick through-hole mask to the through-hole mask matching section. However, in this case, the true shape of the defect occurring in the line pattern near the through hole will be overlooked.

In view of such conventional problems, the present invention is capable of collating a through-hole mask with two optimal positions for each defect candidate data individually, and prevents false alarms from around the through-holes. The present invention aims to provide a printed wiring board inspection device that can perform the following tasks.

[Means for solving problems]

The present invention provides an imaging device that images a wiring pattern on a printed wiring board, and a through-hole image signal from the imaging device.
It consists of a mask unit that creates and stores a mask, a defect detection unit that compares the image signal with the through-hole mask, and a data aggregation unit that aggregates defect data from the defect detection unit. The mask section includes a through-hole basic mask creation section that extracts only the hole portion of the through-hole of the printed wiring board and arbitrarily enlarges or reduces the extracted hole image, and an extraction mask created by the through-hole basic mask creation section. It consists of a mask memory section that stores the hole image as a through-hole mask image.

The defect detection section also includes a defect shape recognition section that recognizes the defect shape from the image signal using a spatial filter that is set with rules assuming the defect shape, and outputs the defect candidate data, and a defect shape recognition section that outputs defect candidate data. Moving the matching position between the basic mask image output from the mask memory unit and the defect candidate data of the defect shape recognition unit on the through-hole mask side in accordance with the shape recognition position for the input image unique to each defect shape recognition unit. a through-hole mask correction unit that provides better matching and expands the size of the matching area as necessary;
The apparatus includes a through-hole mask matching section that matches the corrected through-hole mask output from the through-hole mask correction section with defect candidate data output from the defect shape recognition section. Further, the defect detection sections are arranged according to the number of types of defect shapes.

What is most noteworthy about the present invention is that it includes a mask memory section including the above-mentioned through-hole basic mask creation section, and a defect detection section including the above-mentioned through-hole mask correction section.

In the basic mask creation section, only the hole portion of the through hole of the printed wiring board is extracted, and the image of the extracted hole is arbitrarily enlarged or reduced. The extraction hole image above is 3, for example,
It is created by filtering an image of the drill board captured by the imaging device to extract only the hole portion. Note that the drill board is a board in which holes for through holes are drilled in a base material for a printed wiring board.

In addition, the extracted hole image is reduced or enlarged in advance to an arbitrary size as necessary so that it can be expanded in the through-hole mask correction unit to an appropriate size for the defect candidate data of the defect shape recognition unit. I'll keep it. Note 4: Normally, the size is kept to the minimum required size, expanded as necessary by the through-hole mask correction section, and sent to the through-hole mask verification section.

In addition, as mentioned above, the extraction hole image made to an arbitrary size is
Place memory in the through-hole mask memory section,
It is sent to the through-hole mask correction unit when comparing it with the defect candidate data of the defect shape recognition unit.

The defect detection section is provided for each defect detection system corresponding to the defect shape such as disconnection, chipping, or short circuit. Therefore, the number of defect detection sections is equal to the number of defect shapes to be detected.

Each defect detection section corresponds to the shape of the defect to be detected. It includes a defect shape recognition section, a through-hole mask correction section, and a through-hole mask matching section. The three defect detection sections each include one set of a defect shape recognition section, a through-hole mask correction section, and a through-hole mask comparison section for one type of defect shape.

The defect shape recognition section processes the binary image signal sent from the A/D converter using a spatial filter, as in the prior art. That is, defect candidate data such as disconnections and chips are recognized using a spatial filter designed according to the type of defect shape. Then, the defect candidate data is sent to the through-ball mask matching section.

On the other hand, in the through-hole mask correction section, the same group (
For example, a basic mask image is called from a through-hole mask memory section in order to match a through-hole mask with a corresponding defect shape to defect candidate data detected by a defect shape recognition section (for example, for disconnection detection).

What is important here is that the basic mask image recalled from the through-hole mask memory section is checked at the shape recognition position relative to the input image unique to each defect shape recognition section before being compared with the defect candidate data of the defect shape recognition section. The method is to move the through-hole mask side according to the Furthermore, the size of the compatible region is expanded according to the defect shape of the defect candidate data.

As described above, there are two methods of moving the matching position and expanding the size of the matching area according to the defect candidate data, for example, as shown below.

That is, such a means does not have to have the same size (or resolution) as a spatial filter for one-defect shape recognition.

For example, the one for defect recognition has a resolution of 10 μm and a 20×2
Spatial filter with 0 pixel matrix. The one for mask correction has a 5-resolution of 20 μm and uses a spatial filter of loXIO pixel matrix (loXIO pixel matrix spatial filter). The spatial filter of this through-hole mask correction section has all the outputs of points registered on the matrix connected by OR conditions, and by arbitrarily registering the through-hole mask matching section on the matrix of the spatial filter,
The above functions can be achieved. For example, for nine matrices ABC and DEFGHI as shown in the lower left of Fig. 12, a basic through hole with positive logic is placed in one of BDEFH.
If a mask is input, a corrected mask is obtained with negative logic.

The through-hole mask matching section matches the defect candidate data from the defect shape recognition section with the corrected through-hole mask from the through-hole mask correction section.

When the defect candidate data is within the through-hole mask, it is determined that the defect shape is not a true defect shape. If 7 is the opposite, it is determined that the shape is a true defect and is sent to the data aggregation unit.

In the present invention, a defect shape occurring near a through hole refers to a defect shape in a line pattern near the through hole other than the land provided at the periphery of the opening of the through hole. Furthermore, "around the through hole" refers to the runt and the line pattern near the through hole.

[Operations and Effects] In the present invention, since the above-mentioned through-hole basic mask creation section is provided in the mask section, the extracted hole image can be made to any size and is sent to the through-hole mask correction section. The basic size of the through-hole mask can be chosen arbitrarily. Therefore, the basic size can be set in detail to the minimum dimension, and it is possible to prevent the true defect shape occurring near the 5 through holes from being unable to be detected due to the large through hole mask, as in the conventional case. do not have.

In addition, since the extracted hole image is processed in a Bitmamp-like manner, even if the through hole is irregularly shaped, the recognition process for the through hole portion can be easily performed.

In addition, the through-hole mask correction unit can shift the matching position according to the defect detection system such as wire breakage, and can expand the size of the matching area as necessary, so it can adjust to the type of defect candidate data from around the through-hole. Depending on the through hole
The amount of mask application can be precisely and finely adjusted.

Therefore, according to the present invention, it is possible to individually match each defect candidate data with a through-hole mask at an optimal position and two dimensions, and it is possible to prevent false alarms from around the through-poles.1. We can provide inspection equipment.

〔Example〕

First Embodiment This is an embodiment of the present invention. The printed wiring board inspection apparatus will be explained using FIGS. 1 to 8C.

That is, the inspection apparatus of the present example includes a CCD camera 11 as an imaging device for imaging a wiring pattern 101 on a printed wiring board 10, an A/D converter 12, and the CCD camera, as shown in its entirety in FIG. a mask unit 2 that creates and stores a through-hole mask from the 11 binary image signals;
It consists of a defect inspection section 3 that compares the image signal with the through-hole mask, a data aggregation section 15 that aggregates defect data from the defect detection section 3, and a terminal 16.

The mask unit 2 includes a through-hole basic mask creation unit 21 that extracts only the hole portion of the through-hole of the printed wiring board Fi10 and arbitrarily enlarges or reduces the image of the extracted hole; It consists of a through-hole mask memory section 22 that stores the created extraction hole image as a through-hole mask image.

The defect detection section 3 includes a defect shape recognition section 31, a through-hole mask correction section 35, and a through-hole mask comparison section 36.

The defect detection section 3 is used as a defect detection system for disconnection. In addition to the above-mentioned wire breakage detection, the defect detection section also includes a first
As shown in the figure, there are a defect detection section 3B for missing, a defect detection section 3C for short, and a defect detection section 3D for line defects.

In the defect shape recognition section 31, the A/D
The presence or absence of a defect shape is determined from the binary image signal from the converter 12, and when it is recognized as a defect shape, defect candidate data is output.

In addition, the through-hole mask correction section 35 calculates the matching position between the basic mask image output from the through-hole mask memory section 22 and the defect candidate data at the time of inspection using the input image of each defect shape recognition section patency. Matching is achieved by moving the through-hole mask side in accordance with the corresponding shape recognition position. At the same time, the size of the through-hole mask that can be fitted over the head can be expanded as necessary.

The through-hole mask correction section 35 reads out the through-hole mask related to the disconnection from the through-hole mask memory section 22.

Next, the 5-through-hole mask matching section 36 matches the defect candidate data from the defect shape recognition section 31 with the through-hole mask from the through-hole mask correction section 35, so that the defect candidate data is Inspect whether it is inside the hole mask. If the defect candidate data is included in the through-hole mask, it is determined that the defect shape is not a true defect shape.

On the other hand, in the case opposite to the above, it is determined that the defect shape is a two-true defect shape. Then, the data aggregation unit 15. These data are transmitted to the terminal 16.

The operation of the defect detection section 3 described above is similar to that of the other defect detection section 3B.
, 3C, and 3D are similar except that the defect recognition shapes (chips, cracks, etc.) and through-hole mask correction rules are different.

Next, details of each part will be explained.

First, the through-hole basic mask creation section 21 of the mask section 2
In this step, a basic mask is created as shown in FIG. That is, the area around the through hole is imaged by the CCD camera 11 using a drill board with holes drilled for the through hole or a printed wiring board with no break in the land portion of the through hole. Then, the A/D converter 12 converts it into a binary image signal at an arbitrary threshold level. The two image signals at this time include a through-hole image 4 and unnecessary images 41 such as surrounding dirt and dust, as shown in A of FIG.

Therefore, as shown in B, a spatial filter 451 that removes unnecessary images 41 such as dirt and dust is used to cut out images that are smaller than the set shape. As a result, an extraction hole image 40 shown in C is obtained. A dotted circle 42 around the extracted hole image 40 has the size of the through-hole image/image signal 4 shown in A.

The extracted hole image 4o obtained as described above is obtained by using a restoration spatial filter 452 as shown in D in the same figure.
It can be restored to 1. Further, this restored image 401 can be made into an enlarged image 403 as shown in G using an enlargement spatial filter 453 shown in 2F.

The above-mentioned restoration spatial filter 452. The enlarging spatial filter 453 has a rule that if there is even one pixel input within the specified area, an output is generated, and it can be said that it is a circuit in which all inputs of the specified area are OR-connected.

In addition, the dirt removal spatial filter 451 has a rule that only allows input of a size larger than a specified area to pass.
This is a circuit in which all designated area inputs are AND-connected.

In this way, the through-hole basic mask creation section 21 creates the extracted hole image 40 to any size.

Enlarge or reduce. Of course, the size may be the same as that of the extraction hole image 40. This creates a basic mask image. The basic mask image is stored in the through-hole mask memory section 22.
The data is stored in the memory and read out by the through-hole mask correction unit 35 at the time of inspection.

Next, in the defect shape recognition section 31, the A/D
A binary image signal is input from the converter 12.

Using a spatial filter designed for wire breakage detection, it is detected whether or not there is "defect candidate data" that is considered to be a wire breakage portion in one image signal. and.

When there is defect candidate data, it is output to the through-hole mask matching section 36.

A specific example of the configuration of the spatial filter is shown in FIG. As is known from the figure, the two-spatial filter receives a 22-value image as input, and is constituted by a shift register in the horizontal direction and a line memory in the vertical direction. Then, the polarity of the output from the shift register is inverted, and the defect candidate data is outputted through an AND condition filter. That is, in the defect shape recognition unit 31, the disconnection shape is converted into hardware using this method.

By using this spatial filter, inspection regarding disconnection can be performed.

Next, in the through-hole mask correction section 35, the through-hole mask is corrected as shown in FIG. 4A[ffi and FIG. 4B.

That is, as shown in FIG. 4A, 1 through hole land 5
If there is a pseudo-breakage part 511 in 1, the image signal is divided into a base material image 531, a pattern image 532, and a defective part 533 within the window 53 of the spatial filter for breakage shape recognition.
and are compatible.

Therefore, in the through-ball mask correction section, the fourth
As shown in Figure B, through-hole mask memory section 2
2, the basic mask 44 is called as input.

In the correction spatial filter window 460, data that takes the design of the spatial filter 53 into consideration is set. That is, when the pseudo-disconnection around the through hole is found in the window 53, the position of the hole is checked and the corresponding part is registered in the window 460. This registration area 46 is illustrated in FIG. 4B.

By adjusting the position and size of the registration area 46.

The basic mask 44 can be optimally applied to the defect candidate data.

In the correction spatial filter window 460, if the basic mask matches even one point to the registration area 46,
Output occurs. This output is sent as corrected through-hole mask data to the through-hole mask matching section 36.

FIG. 5 shows a state in which the outputs from the defect shape recognition section 31 and the through-hole mask correction section 35 are collated by a through-hole mask collation section 36 using an AND element.

During opening and opening, a substrate image 61 and a pattern image 6 are displayed in the window 6 of the spatial filter for defect shape recognition and defect detection in the affected area.
2 is set. Hole positions 63 are shown when the rules of this spatial filter are applied around the through-holes.

On the other hand, in the spatial filter for correcting the mask matching position of the through-hole mask correction section 35, the registration area 46, which is the matching point of the basic through-hole mask, is located at a certain position in the window 460. The position of the registration area 46 corresponds to the point of the hole portion 63 of the previous window 6.

Therefore, the defect shape L2m section 3] and the output from the through-hole mask correction section 35 enter the through-hole mask matching section 36 as shown in FIG.

Then, in the through-hole mask matching section 36,
When the basic mask matches the position of the hole portion 63, that is, the position of the registration area 46 of the through-hole mask,
0 (zero) is output.

In other words, it is determined that the defect candidate data of the defect shape recognition unit 31 is not a true defect shape. If the above does not apply,
1 is output, and it is determined that it is a true defect shape.

On the other hand, in order to prevent false alarms from around the through-holes, it is necessary to make the through-hole mask large, but in order to detect defects around the through-holes, it is necessary to keep the through-ball mask small. The optimum size of the through-hole mask differs depending on the type of defect shape. Therefore, in this example, the size of the through-hole mask is changed depending on the type of defect shape.

That is, as shown in FIG. 6, processing is performed by applying the above-described spatial filter for mask matching position correction. That is, the through-hole mask is expanded centering around the position of the hole portion 63 in the window 460, and the pass-through area 461 is set to be large. This allows the through-ball mask to be substantially enlarged relative to the input through-hole mask.

As is known from the above, in one example, the input through hole
The mask is set to the minimum diameter in the through-hole basic mask making section 21, and thereafter the through-hole mask is enlarged according to the shape of the defect. In this way, by setting a large matching tN region of the through-hole mask around the defect matching point, the through-hole mask is substantially enlarged with respect to the input through-hole mask in the through-hole mask correction section. You can

In Fig. 6, if the through-hole mask fits somewhere in the specified head of the spatial filter for 5-mask correction, the defect detection rate will be zero (0) as it is not a true defect shape.
) and outputs 1 for that number.

Note that the spatial filter of the defect shape recognition section has a resolution of IO μm and a window size of 20×20 pixels (40
0 cell) is used. In addition, the spatial filter for the through-hole mask in the through-hole mask correction section is 1
For example, a resolution of 20 μm and a window size of 10×IO pixels (100 cells) are used.

Next, FIGS. 7 to 8C show processing when defect candidate data regarding two wire breaks is input to the defect shape recognition section 31.

FIG. 7 shows a wide part 7 in a through-hole runt image 7]
When there is a narrow width portion 72, defect candidate data is output based on the base material image 61 and the pattern image 62 in the two narrow width portions 72, indicating that there is a disconnection shape 64. On the other hand, there is a true disconnection defect between the wiring portion 73 and the land 71 below the through-hole image, and this is output as a defective portion 6 between the base material image 65 and the pattern image 66.

The design of a spatial filter for recognizing the disconnection shape at this time is shown in FIG. 8A.

On the other hand, a spatial filter for through-hole mask correction is set as shown in FIG. 8B.

A basic through hole is provided in the pixel area indicated by diagonal lines in Figure 8B.
If the mask is suitable, mask processing is performed on the defect candidate data.

Therefore, in the above case, the defect candidate data can be sufficiently masked with a mask that covers the through hole for the more difficult broken wire shape 64 in the through hole, and the broken wire shape 64 is the true defect shape. It can be determined that it is not.

In addition, the true defective portion 68 below the through-hole land is located at the through-hole of the through-hole mask correction section.
Since it is not masked by a mask, it can be determined that it is a disconnection occurring in the line pattern.

In the above, if one through-hole mask correction spatial filter as shown in FIG. 8C is used in the through-hole mask correction section as in the past,
Compared to the case in Figure B, a through-hole mask with a width of three pixels or more is required for each radius of the through-hole. Furthermore, if such a large through-hole mask is always used, the true defect portion 68 will be masked, making it impossible to detect the defect.

As is known from the above, according to the present example, the through-hole mask correction section 35 determines the matching position between the basic mask image and the defect candidate data of the defect shape recognition section through-hole mask correction section 35.
Matching is achieved by moving the mask side, and the size of the matching area is expanded as necessary. In addition, in the through-hole basic mask creation section, the extracted hole image can be enlarged arbitrarily.

It is configured so that it can be reduced.

Therefore, there is no possibility that the true shape of the defect cannot be detected due to the large size of the through-hole mask, as is the case in the past.

Therefore, it is possible to individually match each defect candidate data with a through-hole mask at an optimal position and one dimension, and it is possible to prevent false alarms from around the through-holes.

Second Embodiment This example shows a case where the defect shape is a chipped (line thinned) state, and this will be explained with reference to FIGS. 9A to 11C.

That is, as shown in FIG. 9A, the through-hole land image 5
1 has a thin line portion 515, the thin line shape 6 is formed by the base material image 61 and the pattern image 62 within the window 53 of the spatial filter for defect shape determination.
4, and defect candidate data is output.

Then, as shown in FIG. 9B, the basic mask 44 is input to a spatial filter 460 of the through-hole mask correction section. In this spatial filter window,
Base material portion 6 where the hole is predicted to be located when the defect shape determination spatial filter 53 is adapted to the thin line portion 515
Data must be registered at a point that has the same positional relationship as 1. This is shown in number 9B.

In FIG. 10, when there is a thin line portion in the through-hole land image 7, defect candidate data is output based on the base material image 61 and pattern image 62, indicating that there is a thin line portion 64.

Then, as shown in the figure, a basic through-hole mask 751 indicated by a stepped dotted line is applied twice through a spatial filter for mask correction of a through-hole mask correction section.

In the above case, the thin line portion in the through hole is recognized as a defect candidate by the spatial filter of the defect shape recognition unit having the design shown in FIG. 11A. On the other hand, the basic through-hole mask image is processed by the through-hole mask correction spatial filter shown in FIG. 11B in the through-hole mask correction section. That is, if the basic mask is located somewhere in the specified portion, the defect candidate data is masked and it is determined that the defect shape is not a true defect shape.

In the above, in the through-hole mask correction section.

If a through-hole mask correction spatial filter as shown in FIG. 11C is used as in the past,
A through-hole mask will be uniformly applied to the center of the spatial filter. Therefore, according to this rule, it is not possible to mask thin line defect candidate data using the above-mentioned through-hole mask, resulting in false alarms. Therefore, it becomes necessary to make the through-hole mask even larger, and if it is made larger, the above-mentioned problem occurs.

As described above, the same effects as in the first embodiment can be obtained in the two examples.

[Brief explanation of drawings]

Figures 1 to 8C show the inspection device of the first embodiment.
The figure is a block diagram showing the entire system, Figure 2 is a diagram showing extraction and enlargement of an extraction hole image in the through-hole basic mask creation section, Figure 3 is an explanation of the spatial filter of the defect shape recognition section, and Figure 4A and Fig. 4B is a diagram showing an image related to wire breakage, Fig. 50 is an explanatory diagram of positioning adaptation in the defect shape recessed part and through-hole mask correction part, and Fig. 6 is a diagram showing the matching area in the defect shape recognition part and through-hole mask correction part. FIG. 7 is an explanatory diagram of a through-hole line pattern image regarding wire breakage, FIGS. 8A to 8C are explanatory diagrams of spatial filter application, and FIGS. 9A to 11C [2I is a
Examples are shown, 9th Al15 and 9B are explanatory diagrams of images related to chipping, the 10th is explanatory diagrams of through-hole line pattern images regarding chipping, Figures 11A to 11C are explanatory diagrams of spatial filter application, and 12th The leaps are explanatory diagrams of the spatial filter of the through-hole mask correction section, Figures 13 to 18
The figures show a conventional example; FIG. 13 is a plan view of through holes and line patterns in a printed wiring board; FIG. 14 is a plan view of a through hole land portion in a thin line state;
The figure shows the image signal of the through-hole land part in Figure 13,
FIG. 6 is a Bronk diagram of the inspection device, and FIGS. 17 and 18 are images of defect candidate data. 401. Through-hole image 40, . . . Extraction hole image 44, . . . Basic mask. 50 53, Window 61, Base material image. 62,... Pattern image. 63,, hole portion 710. Through hole land statue.

Claims (1)

[Scope of Claims] An imaging device that images a wiring pattern on a printed wiring board; a mask unit that creates and stores a through-hole mask from an image signal of the imaging device; and a mask unit that creates and stores a through-hole mask from an image signal of the imaging device; The mask unit extracts only the hole portion of the through hole of the printed wiring board and arbitrarily converts the image of the extracted hole. expanded to,
The through-hole basic mask creation section to be reduced and the extraction hole image created in the through-hole basic mask creation section are
and a mask memory section that stores the mask image as a mask image, and the defect detection section recognizes the defect shape from the image signal using a spatial filter in which rules are set assuming the defect shape, The defect shape recognition unit outputs the defect candidate data, and the matching position between the basic mask image output from the mask memory unit during inspection and the defect candidate data of the defect shape recognition unit is determined based on the input image unique to each defect shape recognition unit. A through-hole mask correction unit that matches the through-hole mask side by moving the through-hole mask side according to the shape recognition position and expands the size of the matching area as necessary; and a correction output from the through-hole mask correction unit. A through-hole mask matching unit that matches the completed through-hole mask with defect candidate data output from the defect shape recognition unit, and the defect detection units are arranged according to the number of types of defect shapes. A printed wiring board inspection device featuring: