JP3367450B2 - Electronic component appearance inspection method, appearance inspection apparatus, and recording medium storing a program for causing a computer to execute the appearance inspection process - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection method for an electronic component, a visual inspection apparatus, and a recording medium having a program for causing a computer to implement the visual inspection processing. Appearance inspection method of electronic parts for inspecting the appearance defects
The present invention relates to a visual inspection device and a recording medium in which a program for causing a computer to perform visual inspection processing is recorded.

[0002]

2. Description of the Related Art Conventionally, as a visual inspection method for electronic components, an inspection method or inspection for automatically detecting defects in the manufacturing process such as small holes (hereinafter referred to as voids) formed on the package surface of electronic components. There is a device.

As an inspection method of the first conventional example, Japanese Patent Laid-Open No.
In Japanese Patent No. 280958, an image obtained by photographing a surface of an inspection target is divided into a plurality of unit areas, and binarization processing is performed with an average value of a gray level in each of the unit areas. A method for determining the presence / absence of a defect from the shape is disclosed, and the technique described in the publication will be described as a first conventional example.

FIG. 11 is a block diagram of the defect inspection apparatus of the first conventional example.

In FIG. 11, the scanning beam emitted from the laser light source 20 is applied to the surface of the inspection object 10.
This reflected light is guided to the light receiver 28, and the image signals a1, a2
Is output as. The image signals a1 and a2 are added by the addition means 3
2, the A / D conversion means 34, the density conversion means 36, and the differential filter 38 to output the signal a5 in which the contour of the defect is emphasized. This signal a5 is obtained by the defective address detecting means 40 as the defective address signal Ad, while the signal a5 is obtained.
5 is binarized by the binarization processing means 42, and the defect area extraction means 48 extracts the defect area with reference to the defect address Ad and outputs it as the defect image signal A2.

As a method of determining this defect, the inspection target 1
The address of the defect is obtained based on the differential image of 0, and in the binarization processing means 42, from the first threshold value TH1 obtained from the gray level distribution of the entire differential image and the gray level average value of the neighboring region of the pixel of interest. From the obtained second threshold value TH2, TH3 = TH1-k (TH1-TH2) is set to obtain a third threshold value TH3, and in the defect area extraction means 48, the third threshold value TH3 corresponds to the position of the pixel whose gray level is smaller than the threshold value TH3. It was determined that the surface of the inspection target 10 had a defect.

FIG. 12 is a conceptual diagram of each area in the inspection apparatus of FIG.

FIG. 12 shows the inspection object 10 in FIG.
This is an example in which a more specific electronic component 2 is replaced. The captured image of the light receiver 28 includes a partial area of the package 2a of the electronic component 2 and the terminal 2b. Of these, the region including only the package 2a is the inspection target region Rt. The image of the package 2a captured as the captured image includes the void B which is a defect formed in the package 2a and the unevenness P caused by the surface of the package 2a or reflected light. FIG. 13 shows the defect inspection of FIG. It is a light / dark level L and a binarization level Ls-coordinate C characteristic diagram in an apparatus. FIG. 13 is a view of the level taken along the line XII-XII in FIG. 12, in which a gentle concave portion on the left side of the light and shade level L of the photographed image shows unevenness P, and a sharp concave portion on the right side shows a void B, respectively. .

The void B has a narrow peak width, and the gray level L
, The peak width of the unevenness P is wider than that of the void B, and the gray level L gradually changes.

In FIG. 13, the gray level L is the binarization level L.
A region larger than s is a region without void B and is determined to be normal, and a region with a gray level L smaller than the binarization level Ls is a region with "void B".

As is clear from FIG. 13, in the unevenness P, the light and shade level L slightly decreases over a wide range, but the binarization level Ls obtained as the average value of the light and shade level L also gently decreases. ing.

As the defect inspection method of the second conventional example, as a simpler processing method, an image of the surface of the package 2a is binarized at a constant binarization level over the entire image. There is a method of determining that "the void B exists" when the area of the region where the reflectance of the captured image is small and the gray level is smaller than the binarization level is a preset value or more.

FIG. 14 is a characteristic diagram of the lightness level L and the binarization level Ls-coordinate C in the defect inspection apparatus of the second conventional example. Similar to FIG. 13, FIG. 14 corresponds to the captured image of the package 2a shown in FIG. 12, and as is clear from FIG. 14, the binarization level Ls is constant over the entire area.

In this way, the conventional defect inspection method and apparatus have determined the presence or absence of defects such as voids on the package surface of electronic components.

[0015]

However, the conventional defect inspection method and apparatus have the following problems.

When the electronic component 2 is used as an inspection target,
The image signals a1 and a2 of the package 2a are as shown in FIG.
3, as shown in FIG. 14, the light intensity of the irradiation light source 1 that irradiates the surface of the package 2a is different depending on the direction and place, the resin component of the package 2a and the surface state are not uniform, and the mold of the package 2a is Often, the reflectance of the surface is partially different due to stains etc. adhering from etc., in such a case, in a part of the shooting area,
The unevenness P is likely to occur, in which the gray level L of the image signals a1 and a2 of the package 2a is totally different from other portions.

Accordingly, when the unevenness P and the void B have the same gradation level in the gradation image, it is judged that the gradation level L is smaller than the binarization level Ls after the binarization process. Therefore, although there is no void in the package 2a, there is a problem that it is easy to erroneously determine that "void B exists".

Further, in the defect inspection apparatus of the first conventional example, in order to obtain the average value of the gray level L for each of a plurality of unit areas,
Spatial filtering processing was performed based on the information of each pixel and a large number of pixels surrounding the pixel, resulting in an enormous amount of data to be processed, a long inspection time, and a large shade value of the stamp character near the stamp character. In addition, the average value of the light and shade levels in the unit area becomes high, and the binarization level is set to be high, so that there is a problem that normal inspection cannot be performed.

Further, in the defect inspection apparatus of the second conventional example, FIG.
As shown in FIG. 4, the binarization processing is simply performed at the constant binarization level Ls over the entire inspection target region Rt. However, in this method, the gray level L is entirely in the vicinity of the unevenness P in FIG. Therefore, there is a problem that it is erroneously determined that “void B exists” near the unevenness P.

In the present invention, the appearance inspection method, the appearance inspection apparatus, and the appearance inspection of the electronic component, which can surely discriminate only the true defect without being affected by the unevenness included in the photographed image of the package of the electronic component, etc. A recording medium for recording a program for causing a computer to realize a process is provided.

[0021]

In order to solve the above problems, the present invention employs the following novel characteristic methods and means.

The feature of the appearance inspection method for electronic parts of the present invention is that the surface of the inspection object (102 in FIG. 2) is photographed to obtain the gray level (L in FIG. 4) for each coordinate (C in FIG. 2). , A continuous area (R11 to Rl in FIG. 5) of coordinates (C) in which the gray level (L) is smaller than a preset value (Ls in FIG. 4).
Regions (Rl2 and Rl3 in FIG. 5) whose area is larger than a preset value among 3) are determined as void candidate regions (Rc2 in FIG. 6A and Rc3 in FIG. 6B), and the void candidate region ( (Rc2, Rc3) are spread around to obtain void candidate expansion regions (Re2 in FIG. 7A, Re3 in FIG. 7B), and the gray level (L) of each void candidate expansion region (Re2, Re3) is calculated. The differential value is calculated, and the void candidate expansion area (Re
2, Re3), an area (S2, S3 in FIG. 9) whose differential value is larger than a preset differential value is obtained, and a void candidate region (Rc2) having an area (S2, S3) larger than the preset area value is obtained. , Rc3) is determined to have a defect.

The feature of the appearance inspection apparatus for electronic parts of the present invention is that the surface of the inspection object (102 in FIG. 2) is photographed and the gray level (L in FIG. 4) is obtained for each coordinate (C in FIG. 2). Coordinates (C) where the image pickup means (103 to 105 in FIG. 1) and the gray level (L) are smaller than a preset value (Ls in FIG. 4).
Area larger than the continuous area of
A void candidate area extracting unit that obtains areas (Rl2 and Rl3 in FIG. 5) having an area larger than a preset value among 3) as void candidate areas (Rc2 in FIG. 6A and Rc3 in FIG. 6B). (106 to 108) and the void candidate region (Rc2, Rc3) are expanded to the periphery to obtain a void candidate extended region (Re2 in FIG. 7A, Re3 in FIG. 7B), which is a void candidate region expanding means ( 109) in FIG. 1 and the gray level (L) for each of the void candidate expansion regions (Re2, Re3)
Differentiating means (110 in FIG. 1) for calculating the differential value of and the area calculation for calculating the area (S2, S3 in FIG. 9) whose differential value is larger than the preset differential value for each void candidate expansion region (Re2, Re3) Means (110 to 112 in FIG. 1) and a determining means (113 in FIG. 1) for determining that a defect exists in the void candidate regions (Rc2, Rc3) having areas (S2, S3) larger than a preset area value. ) And.

The characteristic of the recording medium in which the program for causing the computer to realize the appearance inspection processing of the electronic parts of the present invention is recorded is that the surface of the inspection object (102 in FIG. 2) is photographed and the coordinates (C in FIG. 2) are taken. ), The gray level (L in FIG. 4) is calculated for each value, and the gray level (L) is set to a preset value (L in FIG. 4).
s) A continuous region of smaller coordinates (C) (Rl in FIG. 5)
1 to Rl3), the area (Rl2, Rl3 in FIG. 5) whose area is larger than a preset value is a void candidate area (FIG. 6).
Rc2 in (a) and Rc3 in FIG. 6 (b) are obtained, and the void candidate regions (Rc2, Rc3) are spread to the periphery to expand the void candidate extended region (Re2 in FIG. 7A, Re in FIG. 7B).
3) is calculated, the differential value of the gray level (L) for each void candidate expansion region (Re2, Re3) is calculated, and the differential value is larger than the preset differential value for each void candidate expansion region (Re2, Re3). (S2, S3 in FIG. 9) is determined, and it is determined that a defect exists in the void candidate regions (Rc2, Rc3) having an area (S2, S3) larger than a preset area value.

By adopting such a method and means, the recording medium on which the program for causing the computer to implement the appearance inspection method, appearance inspection device and appearance inspection process of the electronic component of the present invention is first void. The candidate area is extracted, and then the amount of change in the gray level at each coordinate in these void candidate areas is calculated.The presence or absence of voids is determined by whether this amount of change is greater than or equal to a reference value. By eliminating them, it is possible to reliably determine the presence or absence of defects such as voids.

[0026]

FIG. 1 is a block diagram of a visual inspection apparatus for electronic parts according to a first embodiment of the present invention.

The irradiation light source 101 emits irradiation light.

The electronic component 102 reflects the irradiation light from the irradiation light source 101 according to the reflectance of the surface.

The CCD camera 103 images the reflected light from the electronic component 102 over a certain area and outputs it as an analog image signal Sa.

The analog image signal Sa from the CCD camera 103 is A / D converted by the A / D conversion means 104 and output as digital grayscale image data Db.

The grayscale image data storage means 105 temporarily stores the digital grayscale image data Db therein.

The first binarization means 106 reads the digital grayscale image data Db from the grayscale image data storage means 105, and the grayscale level L (FIG. 4) is previously stored therein for each coordinate C (FIG. 2). Binarization level Ls (Fig. 4)
If the following is true, the first binarized image data Dc in which the coordinate C is set to the “1” level and in the opposite case to the “0” level is generated and output.

The labeling means 107 is supplied with the first binarized image data Dc, and receives the first binarized image data Dc.
Areas each having a continuous "1" level are designated as labeling areas Rl1 to Rl3 (Fig. 5).
The label name and area value of 11 to Rl3 are output as a set as label data Dd.

The label candidate data Rd is supplied to the void candidate area extracting means 108, and the labeling areas Rl1 to Rl are supplied.
3 (FIG. 5), only the labeling areas R12 and R13 having a larger area than the area set in advance are set as void candidate areas Rc2 and Rc3 (FIGS. 6A and 6B), respectively.
And output as void candidate area data De.

The void candidate area expanding means 109 is configured to detect each of the void candidate areas Rc2, R represented by the void candidate area data De.
c3 (FIGS. 6 (a) and 6 (b)) is expanded to the periphery by a certain range, and void candidate expansion regions Re2 and Re3 (FIG.
(A), (b)), and the void candidate area expansion data Df
Output as.

The differentiating means 110 is supplied with the digital grayscale image data Db and the void candidate area expansion data Df,
With respect to the digital grayscale image data Db in each of the void candidate extension regions Re2 and Re3 (FIGS. 7A and 7B) represented by the void candidate region extension data Df, the grayscale level L at each coordinate C is differentiated to obtain the grayscale level L. The differential gray level, which is the amount of change, is obtained and output as differential image data Dg.

The second binarizing means 111, for each coordinate C (FIG. 4) in each of the void candidate expansion regions Re2, Re3 (FIGS. 7A and 7B) represented by the differential image data Dg, If the differential gray level L is equal to or higher than the second binarization level stored in advance, the coordinate area C is set to the "1" level, and otherwise the coordinate area C is set to the "0" level.
2, Ri3 (FIGS. 8A and 8B) are respectively obtained and output as the second binarized image data Dh.

The area measuring means 112 is supplied with the second binarized image data Dh and measures the number of "1" for each of the differential areas Ri2, Ri3 to obtain area values S2, S3 (FIG. 9), respectively. It is output as area data Di.

The judging means 113 compares each area value S2, S3 (FIG. 9) represented by the area data Di with an area value preset inside, and determines at least one of the area values S2, S3.
If one is larger than a preset value, "the void B exists" in the void candidate regions Rc2, Rc3.
Then, the determination signal Sj is output.

FIG. 2 is a conceptual diagram of each area in the appearance inspection apparatus for electronic parts of FIG.

In FIG. 2, the image captured by the CCD camera 103 is the package 102a of the electronic component 102 and the terminal 1.
A part of the area 02b is included. Of these, the region including only the package 102a is the inspection target region Rt. The image of the package 102a photographed as a photographed image shows void B which is a defect formed in the package 102a.
FIG. 3 is an inspection processing flowchart in the appearance inspection apparatus for electronic components of FIG. 1, including the surface of the package 102a and the unevenness P caused by reflected light.

The irradiation light emitted from the irradiation light source 101 of FIG. 1 is reflected on the surface of the package 102a (FIG. 2), and CC
The light incident on the D camera 103 is converted into A / D conversion means 104.
The grayscale image data storage means 105 is converted to digital grayscale image data Db which is analog-to-digital converted by the digital signal and indicates the grayscale level L (FIG. 4) at each coordinate C (FIG. 2).
Is temporarily stored in (step S301).

The first binarizing means 106 of FIG. 1 reads the digital grayscale image data Db stored in the grayscale image data storage means 105 (step S302).

The first binarizing means 106 shown in FIG. 1 sets the gray level L (FIG. 4) represented by the digital gray-scale image data Db for each coordinate C (FIG. 2) in advance as a binary value. Compared with the binarization level Ls (FIG. 4), the coordinate C whose gray level L is lower than the binarization level Ls is set to the “1” level and the opposite coordinate C is set to the “0” level for each coordinate C. It is output as the binarized image data Dc (step S303).

The labeling means 107 in FIG. 1 labels the continuous regions of "1" level represented by the first binarized data image Dc into the respective labeling regions R11 to R13 (FIG. 5).
Then, the label name and the area of each of the labeling areas R11 to R13 are output as the label data Dd as a set (step S304).

The void candidate area extracting means 108 of FIG.
Each labeling area R11 to R represented by the label data Dd
Among the l3 (FIG. 5), only the labeling regions Rl2 and Rl3 which are larger than the area set in advance as the void candidate regions Rc2 and Rc3 (FIGS. 6 (a) and (b)),
The data is output as void candidate area data De (step S
305).

The void candidate area expanding means 109 shown in FIG.
Each void candidate area R represented by the void candidate area data De
c2 and Rc3 (FIGS. 6 (a) and 6 (b)) are each expanded to the surroundings by a certain range, and each void candidate expansion region Re2
The void candidate area expansion data Df representing Re3 (FIGS. 7A and 7B) is output (step S306).

The differentiating means 110 of FIG. 1 differentiates the gray level L (FIG. 4) at each coordinate C (FIG. 2) in the void candidate area expansion areas Re2 and Re3 (FIGS. 7A and 7B). Then, the differential gray level is calculated to obtain the differential image data Dg
Is output (step S307).

The second binarizing means 111 shown in FIG. 1 uses the void candidate expansion regions Re2 and Re3 (FIGS. 7A and 7B).
For each time, the differential gray level of each coordinate C (FIG. 4) is compared with the internally set value, and the coordinate C having a higher differential gray level than the internally set value is the “1” level and the opposite coordinate. Differentiating areas Ri2 and Ri3 (see FIG.
(A) and (b)) are respectively obtained and output as the second binarized image data Dh (step S308).

The area measuring means 112 of FIG.
The area of "1" level is measured for each of i2 and Ri3 (FIGS. 8A and 8B) to obtain area values S2 and S3, respectively, which are output as area data Di (step S309).

The determination means 113 in FIG. 1 uses the area data Di
The differential areas Ri2 and Ri3 represented by (Fig. 8 (a),
(B)) The respective areas S2, S3 (FIG. 9) are respectively compared with the areas set inside beforehand, and when the areas are larger than the areas set inside, the respective differential areas Ri2,
Each void candidate region Rc2, Rc3 including Ri3 (see FIG.
It is determined that there is a defect in (a) and (b), and the determination signal Sj is output (step S310).

FIG. 4 is a characteristic diagram of the lightness level L and the binarization level Ls-coordinate C in the appearance inspection apparatus for electronic parts of FIG.

FIG. 4 is a view of the level seen along the line II-II in FIG. 2, in which the gentle concave portion on the left side is uneven P.
The sharp recess on the right side is due to the void B.

In FIG. 4, the gray level L is the binarization level Ls.
The smaller areas are labeled areas R11 and R12.

FIG. 5 is a conceptual diagram of the labeling areas R11 to R13 in the appearance inspection apparatus for electronic parts of FIG. As shown in FIG. 5, in the binarized image data Dc binarized by the binarizing means 106, a label is attached to each region where “1” level continues, and labeling regions Rl1 to Rl3. The areas of the labeling regions Rl1 to Rl3 are 4, 14 and 13, respectively.

FIG. 6 is a conceptual diagram of the labeling candidate regions Rc2, Rc3 in the electronic component appearance inspection apparatus of FIG.

When the area (previously set area) = 6, the void candidate area extracting means 108 has only the labeled areas Rl2 and Rl3 in FIG. 5 which are larger than 6 as void candidate areas Rc2 and Rc3, respectively. It is output as void candidate area data De.

FIG. 7A is a conceptual diagram of the void candidate expansion region Re2 in the electronic component appearance inspection apparatus of FIG.
(B) is a conceptual diagram of a void candidate expansion region Re3 in the electronic component appearance inspection apparatus of FIG. 1.

The void candidate area expanding means 109 expands by 2 pixels around the respective coordinates C in the void candidate areas Rc2, Rc3 to the void candidate expanded area R, respectively.
e2 and Re3 are generated.

As the expansion method, a maximizing filter of size (3 × 3) centered on each coordinate C is processed by the number of pixels to be expanded, or each coordinate C is centered (5 ×).
5) A method in which the size maximizing filter is processed once and expanded by two pixels can be considered, but the present invention does not limit this expansion method.

FIG. 8 (a) is a conceptual diagram of the differential area Ri2 in the appearance inspection apparatus for electronic parts of FIG. 1, and FIG. 8 (b) is FIG.
FIG. 3 is a conceptual diagram of a differential area Ri3 in the electronic component appearance inspection device of FIG.

The gradation level L of each coordinate C in the void candidate area expansion areas Re2 and Re3 is differentiated by the differentiating means 110 to obtain the respective differential gradation levels.

In the void B area shown in FIG. 8A, the light and shade level L changes rapidly near the outer periphery of the void B.
In the differential area Ri2, the area value S2 of the "1" level having a high differential gray level is as large as S2 = 10. On the other hand, Fig. 8
In the area of unevenness P shown in (b), the lightness level L gradually changes, and thus the area value S3 of the "1" level having a high differential lightness level in the differential area Ri2 becomes small, that is, S3 = 2.

This differential gray level is the coordinate C to be calculated.
Is calculated from the maximum value of the difference between the lightness level L and the lightness level L in the vicinity thereof, the sum of the absolute values of the differences between the lightness level L of the coordinate C to be calculated and the lightness level L in the vicinity thereof, and the like. However, in the present invention, the differentiation method is not limited.

FIG. 9 is a conceptual diagram of the determination of the void B in the appearance inspection apparatus for electronic parts of FIG.

As described above, since the area values S2 and S3 are large in the differential area Ri in which the void B is present, the differential area R having the area value equal to or larger than a certain value is determined in the judging means 113.
It is determined that “void B exists” in the void candidate region Rc2 including i.

As described above, in the present embodiment, (1)
A void candidate area in which a void may exist is extracted, (2) each void candidate expanded area is obtained by expanding each of these void candidate areas, and (3) a gray level at each coordinate in each void candidate expanded area. Is differentiated to obtain the change amount of the light and shade level, (4) The area of the differential region where this change amount is large is obtained, and (5) When this area is equal to or larger than a certain value, it is determined that a void exists in the void candidate region. By doing so, it is possible to eliminate the influence of unevenness, reliably detect the presence or absence of defects such as voids, and significantly reduce erroneous determination.

Next, a modified example of this embodiment will be described.

As a first modification, in the labeling means 107 of FIG. 1, a part of the inspection target region Rt of FIG.
A mask area excluded from the void candidate areas Rc2 and Rc3 may be set.

As a second modification, the labeling means 107 in FIG. 1 calculates the areas of the labeling areas Rl1 to Rl3, and the void candidate area extracting means 108 calculates the void candidates from the areas of the labeling areas Rl1 to Rl3. Region Rc2, R
Instead of extracting c3, the labeling means 107 causes the most distant 2 on the outer circumference of each of the labeling areas R11 to R13.
It is also possible to calculate the distance between the points and extract only the labeling regions R12 and R13 whose void candidate region extracting means 108 has determined that this distance is equal to or greater than a preset threshold value as the void candidate regions Rc2 and Rc3, respectively. .

As a third modification, the labeling means 107 in FIG. 1 calculates the areas of the labeling areas Rl1 and Rl2, and the void candidate area extracting means 108 calculates the voids from the areas of the labeling areas Rl1 and Rl2. Instead of determining the presence or absence, the labeling means 107 causes the labeling areas Rl1 to Rl3 to have areas and the labeling areas Rl.
1 to Rl3 and both of the distances between the most distant points on the outer circumference are calculated, and the void candidate region extracting means 108 sets thresholds for both the area and the distance in advance, and either one of them is set. Are labeled regions Rl2 and Rl3 that are larger than the respective thresholds, and void candidate regions Rc2 and Rc
You may extract as 3.

Further, the circumscribing rectangle may be obtained for each of the void candidate regions Rc2, Rc3 by the void candidate region expanding means 109, and the rectangular regions obtained by expanding the circumscribing rectangle by a certain range may be used as the void candidate expanding regions Re2, Re3, respectively.

FIG. 10 is a block diagram of the appearance inspection apparatus for electronic parts according to the second embodiment of the present invention. The present embodiment describes an embodiment suitable for a case where the electronic component appearance inspection apparatus according to the first embodiment of FIG. 1 is configured especially on a computer.

The appearance inspection apparatus for electronic parts of the present embodiment comprises an input unit 201, a CPU 202, and a memory 203.
, Irradiation light source 204a, CCD camera 204b, A
The A / D converter 204c, the display processing unit 205, the display unit 206, the external storage device 207, the interface unit 208, and the bus 209 are included.

The input section 201 is an operation means such as a keyboard and a remote controller, which is composed of various operation keys.
Various instructions are given to the PU 202. This means is realized by an alphanumeric keyboard, a dedicated input device, a mouse, a remote controller, etc., especially in a computer.

The CPU 202 is composed of a microcomputer or the like, and operates by a program or the like which is built in or supplied from the outside and controls each unit.

The memory 203 is composed of a memory such as a RAM and stores various data under the control of the CPU 202. This means, especially in computers, RAM
It is realized by various recording media such as a flash memory and a hard disk.

The irradiation light source 204a emits irradiation light.

The CCD camera 204b is the electronic component 102.
The reflected light from is imaged over a certain area and output as an analog image signal Sa.

The A / D converter 204c performs analog / digital conversion on the analog image signal Sa from the CCD camera 204b and outputs it to the bus 209 as digital grayscale image data Db.

The display processing unit 205 is connected to the bus 209 and converts the image data sent via the bus 209 into a display signal Sdp and outputs it.

The display unit 206 is a video display means such as a display device or a monitor, and displays the display signal Sdp as a video. This means, especially in computers,
It is realized by various display devices.

The external storage device 207 is a storage medium that stores various processing programs of the CPU 202, data similar to that stored in the memory 203, and the like.
Various data are written and read under the control of the PU 202. This means, especially in computers,
It is realized by various recording media such as AM, flash memory, and hard disk.

The interface unit 208 includes the CPU 20.
It is an interface with the outside that is connected to 2.

The bus 209 includes an input unit 201 and a CPU 20.
2, the memory 203, the A / D converter 204c, the display processing unit 205, the external storage device 207, and the interface unit 208 are mutually connected.

The appearance inspection method for electronic parts according to the second embodiment of the present invention is the same as the appearance inspection method for electronic parts according to the first embodiment.

Next, a description will be given of a recording medium recording a program for causing a computer to implement the appearance inspection processing for electronic parts according to the second embodiment of the present invention.

In the appearance inspection method for an electronic component and the appearance inspection device for an electronic component according to the first embodiment, a program for causing a computer to implement the appearance inspection process for an electronic component is used as a control program for a dedicated appearance inspection device. Although built-in, in the present embodiment, similar processing is realized by a software program or the like in a general-purpose computer device or the like.

As a recording medium of this software program, it may be stored in an external recording device 207 such as a memory card, a floppy (registered trademark) disk, a hard disk, a CD-ROM, a DVD-RAM, or on the data storage section 203. A storage area dedicated to the program may be provided to store the program read from the external recording device 207.

Other configurations and processing flowcharts are the same as those of the recording medium recording the program for realizing the appearance inspection method, appearance inspection apparatus and appearance inspection processing method for the electronic parts of the first embodiment in a computer. .

In each of the above-described embodiments, the binarization processing is performed for each pixel of the images captured by the CCD cameras 103 and 204b. However, in order to speed up the processing, a plurality of pixels are collectively binarized. I don't mind.

[0092]

By adopting the above-mentioned methods and means, a recording medium recording a program for causing a computer to implement the appearance inspecting method, appearance inspecting apparatus and appearance inspecting apparatus for electronic parts according to the present invention, It has the following effects.

As a first point, first, a void candidate area is found, then the void candidate area is expanded to the periphery to obtain a void candidate expanded area, and then the change amount of the gray level in each void candidate expanded area is calculated. Since the voids and the unevenness are discriminated from the area of the large differential region, there is an advantage that the unevenness is not affected and erroneous determination of the unevenness as the void is significantly reduced and the inspection accuracy can be greatly improved.

As a second point, it is sufficient to extract only the void candidate regions and calculate the feature values of these void candidate regions, which has the advantage of being able to significantly speed up the inspection process.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an appearance inspection apparatus for electronic parts according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of each area in the electronic component appearance inspection apparatus of FIG.

FIG. 3 is an inspection processing flowchart in the appearance inspection apparatus for electronic parts of FIG.

FIG. 4 is a characteristic diagram of a lightness level L and a binarization level Ls-coordinate C in the appearance inspection apparatus for electronic parts of FIG.

5 is a conceptual diagram of labeling regions Rl1 to Rl3 in the appearance inspection apparatus for electronic components of FIG.

6A is a conceptual diagram of a void candidate region Rc2 in the electronic component appearance inspection device of FIG. 1, and FIG. 6B is a conceptual diagram of a void candidate region Rc3 in the electronic component appearance inspection device of FIG.

7A is a conceptual diagram of a void candidate extension region Re2 in the electronic component appearance inspection apparatus of FIG. 1, and FIG. 7B is a void candidate extension area R in the electronic component appearance inspection apparatus of FIG.
It is a conceptual diagram of e3.

8A is a conceptual diagram of a differential region Ri2 in the electronic component appearance inspection apparatus of FIG. 1, and FIG. 8B is a conceptual diagram of a differential area Ri3 in the electronic component appearance inspection apparatus of FIG.

FIG. 9 is a conceptual diagram for determining a void B in the electronic component appearance inspection apparatus of FIG. 1.

FIG. 10 is a block configuration diagram of an appearance inspection device for electronic parts according to a second embodiment of the present invention.

FIG. 11 is a block configuration diagram of a defect inspection apparatus of a first conventional example.

12 is a conceptual diagram of each area in the defect inspection apparatus of FIG.

13 is a gray level L in the defect inspection apparatus of FIG.
3 is a characteristic diagram of a binarization level Ls and a coordinate C. FIG.

FIG. 14 is a characteristic diagram of a lightness level L and a binarization level Ls-coordinate C in a defect inspection apparatus of a second conventional example.

[Simple explanation of symbols]

2 electronic components 2a package 2b terminal 10 inspection target 20 laser light source 28 Light receiver 32 addition means 34 A / D conversion means 36 Density conversion means 38 Differential filter 40 defective address detecting means 42 Binarization processing means 48 defective area extracting means 101 Irradiation light source 102 electronic components 102a package 102b terminal 103 CCD camera 104 A / D conversion means 105 grayscale image data storage means 106 first binarization means 107 labeling means 108 Void candidate area extraction means 109 Void candidate area expansion means 110 differentiating means 111 Second Binarization Means 112 Area measuring means 113 determination means 201 Input section 202 CPU 203 memory 204a irradiation light source 204b CCD camera 204c A / D converter 205 display processing unit 206 display 207 External storage device 208 Interface part 209 bus

Claims (12)

(57) [Claims] 1. A surface of an object to be inspected is photographed to obtain a gray level for each coordinate, and the area is larger than a preset value in a continuous region of coordinates where the gray level is smaller than a preset value. Is obtained as a void candidate area, the void candidate area is expanded to obtain a void candidate expanded area, the differential value of the gray level of each of the void candidate expanded areas is obtained, and the differential value is calculated for each of the void candidate expanded areas. An appearance inspection method for an electronic component, comprising: determining an area larger than a preset differential value, and determining that a defect exists in the void candidate area having an area larger than a preset area value. 2. The appearance inspection method for an electronic component according to claim 1, wherein an area excluded from the void candidate area is set in an area of the photographed image. 3. The gray level is preset instead of obtaining a region having a larger area than a preset value out of a continuous region having coordinates smaller than the preset gray level as the void candidate region. 3. A void candidate region is obtained as a void candidate region in which a distance between two points that are most distant from each other on the outer circumference is determined as a void candidate region among continuous regions whose coordinates are smaller than the specified value. Appearance inspection method for electronic parts. 4. A void candidate area is obtained by expanding a rectangular area circumscribing the void candidate area, instead of expanding the void candidate area to the outside to obtain the void candidate expanded area. Claim 1
Or the appearance inspection method for an electronic component according to any one of 2). 5. An image pickup means for photographing a surface of an object to be inspected to obtain a gray level for each coordinate, and an area having a preset value in a continuous region of coordinates whose gray level is smaller than a preset value. A void candidate area extracting means for obtaining a larger area as a void candidate area, a void candidate area expanding means for expanding the void candidate area to obtain a void candidate expanded area, and a differentiation of the gray level for each of the void candidate expanded areas. A differentiating means for obtaining a value, an area calculating means for obtaining an area where the differential value is larger than a preset differential value for each of the void candidate expansion areas, and a void candidate area having an area larger than a preset area value A visual inspection apparatus for electronic parts, comprising: a determination unit that determines that it is determined that a defect exists. 6. The appearance inspection apparatus for an electronic component according to claim 5, wherein an area excluded from an object to which the label is attached is set in an area of the photographed image. 7. The void candidate area extracting means is operative to obtain, as a void candidate area, an area having an area larger than a preset value among continuous areas having coordinates whose gray level is smaller than a preset value. 6. A void candidate region is defined as a region in which the distance between two points that are most distant from each other on the outer circumference is a constant region or more among continuous regions whose coordinates are smaller than a preset value. 7. A visual inspection device for an electronic component according to any one of 6 and 6. 8. The void candidate area extracting means circumscribes each of the areas having continuous gray levels instead of obtaining continuous areas having the gray level smaller than a preset value as void candidate areas. 7. The appearance inspection apparatus for an electronic component according to claim 5, wherein a rectangular area to be obtained is obtained as a void candidate area. 9. A surface area of an object to be inspected is photographed to obtain a gray level for each coordinate, and an area is larger than a preset value in a continuous region of coordinates where the gray level is smaller than a preset value. Is obtained as a void candidate area, the void candidate area is expanded to obtain a void candidate expanded area, the differential value of the gray level of each of the void candidate expanded areas is obtained, and the differential value is calculated for each of the void candidate expanded areas. Realize the appearance inspection process of electronic parts on a computer, which is characterized by determining an area larger than a preset differential value and determining that a defect exists in the void candidate area having an area larger than the preset area value. A recording medium on which a program for recording is recorded. 10. The computer for realizing a visual inspection process of an electronic component according to claim 9, wherein a region excluded from the void candidate region is set in a region of the photographed image. A recording medium recording a program. 11. The shade level is preset instead of obtaining a region having a larger area than a preset value among continuous regions whose coordinates are smaller than a preset value as the shade level, as the void candidate region. 11. The void candidate region is a region in which the distance between the two most distant points on the outer circumference is equal to or larger than a certain value among the continuous regions having coordinates smaller than the determined value, as a void candidate region. A recording medium in which a program for causing a computer to implement a visual inspection process for electronic components is recorded. 12. A void candidate area is obtained by expanding a rectangular area circumscribing the void candidate area, instead of expanding the void candidate area to obtain a void candidate expanded area. Claim 9
Or a recording medium having recorded therein a program for causing a computer to implement the appearance inspection process of the electronic component.