KR20130077813A - Device for detecting print substrate - Google Patents

Abstract

[Problem] A pad, a resist, or the like is irradiated with light depending on the characteristics to perform an accurate inspection.
RESOLUTION In the inspection apparatus 1 of the printed circuit board 7, it is red LED 32 arrange | positioned at the 1st angle which becomes bright field illumination with respect to the camera 6, and is diffused illumination by a green fluorescent lamp. A second color light source 4 and a third color light source 5 made up of a blue LED disposed at a third angle of darkfield illumination with respect to the camera 6, and from the first color light source 3. The image of the printed board 7 is taken by the camera 6 using the light to the third color light source 5, and the pad surface is made by using the image by the light from the red LED 32 which is the bright field illumination. Of the wound (71b), scars (71c), and discoloration. Moreover, the formation state of the pad 71 outline 71a is examined by the image by the light from the fluorescent lamp which is green diffused illumination. Further, the image from the third color light source 5, which is a blue LED, is used to inspect the resist 72 for cracks and blemishes, as well as for disconnection or shorting of the resist under pattern.

Description

Inspection device for printed boards {DEVICE FOR DETECTING PRINT SUBSTRATE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for a printed circuit board capable of accurately inspecting pads, resists, and the like formed on the surface of the printed circuit board.

In general, an image of a pad, a resist or the like formed on the surface of a printed board is acquired by a camera, and automatically inspected based on the image.

Here, when acquiring the image of a printed board by such an inspection apparatus, when light is irradiated (that is, bright field illumination) from the direction which becomes a specular reflection with respect to a camera, it will light in the corner etc. of an edge or a part which has an unevenness | corrugation. This strongly reflects, and the shape of the edge cannot be detected well. For this reason, generally, when acquiring the image of a printed board, it acquires an image by the dark field illumination which irradiates light from the direction different from the direction which becomes a regular reflection with respect to the camera (4th paragraph of patent document 1). , Paragraph 30 of Patent Document 2).

Prior art literature

Patent literature

Patent Document 1: Japanese Patent Publication No. 2002-535687

Patent Document 2: Japanese Patent Application Laid-Open No. 2008-268141

However, when the pad, the resist, or the like of the printed board is inspected by darkfield illumination in this manner, the following problems are caused.

In other words, when inspecting the printed board, the surface of the pad, the presence of irregularities of the pad, the defect of the pad outline, the discoloration of the surface of the pad, the peeling of the resist, the ink smear, and the like are inspected. If it acquires, an image can be acquired to some extent with respect to the outline of a pad, but the wound etc. which were formed in the surface of a pad become dark, and a clear image cannot be acquired.

Moreover, since a pad, a resist, etc. each have its own color, reflectance, etc., it is preferable to irradiate and test the light according to each characteristic.

Accordingly, an object of the present invention is to provide an inspection apparatus for a printed circuit board which can perform inspection with high precision by irradiating light according to characteristics on a pad, a resist, or the like.

That is, in order to solve the said subject, in the inspection apparatus of the printed circuit board which examines the formation state of the pad or resist formed in the printed circuit board, the 1st color arrange | positioned at the 1st angle which becomes bright field illumination with respect to a camera A light source, a second color light source which is diffused illumination by fluorescent lamps, and a third color light source arranged at a third angle of darkfield illumination with respect to the camera, wherein the light from the first color light source to the third color light source is provided. Using a camera to take an image of the printed board, and using the first inspection means for inspecting the pad surface for scratches using the image of the first color light source, and using the image of the second color light source Second inspection means for inspecting the formation state of the pad contour and third inspection means for inspecting the formation state of the resist using the image of the third color light source.

In this way, since the image can be acquired from the color or angle of the light source in accordance with the characteristics of the pad or the resist, it becomes possible to perform an optimal inspection in accordance with the characteristics of each inspection area.

Moreover, in this invention, a 3rd color light source is provided in the direction which forms an acute angle with respect to the optical axis of the camera provided in the diagonal direction with respect to the normal line of a printed circuit board.

In this way, extremely small scratches or irregularities reflected on the surface of the pads are not acquired, and diffusely reflected light such as thinner resists having a very high surface roughness is obtained, thereby effectively forming the resist. It becomes possible to check.

Further, the first color light source is a red LED light source, the second color light source is a green light source or a blue light source, and the third color light source is an index blue LED light source or a green LED light source different from the second color light source. .

This increases the reflectance of the red wavelength on the metal surface such as the pad, so that an image such as a wound or a scar can be obtained, and green or blue for a color close to green or blue, such as a resist. The dark field illumination of can obtain a surface image accurately.

In addition, when the state of formation of the resist is inspected by the third inspection means, the pattern region is inspected using the image of the second color light source as well.

By doing in this way, the part of the resist which cannot be examined by the light source of each color can be examined by the light source of a different color.

Specifically, on the basis of the image of the third color light source, a region of the upper substrate resist and the resist lower pattern is separated using a predetermined luminance threshold value, and the region of the resist lower pattern. Is expanded, and the application state of the resist on the outer substrate is examined.

Further, based on the image of the third color light source, the resist on the substrate and the region under the resist pattern are separated using a predetermined luminance threshold, and there is a disconnection or a short with respect to the region of the resist under pattern. Check it.

According to the present invention, there is provided a device for inspecting a printed circuit board for inspecting pads or resists formed on a printed circuit board, the apparatus comprising: a first color light source disposed at a first angle of brightfield illumination with respect to a camera, and diffusion by fluorescent lamps; A second color light source, which is an illumination, and a third color light source disposed at a third angle of darkfield illumination with respect to the camera, and using a light from the first color light source to the third color light source to the camera to print on the printed board. Image of the first color light source, the first inspection means for inspecting the pad surface for scratches using the image of the first color light source, and the state of formation of the pad contour using the image of the second color light source, which is the diffuse illumination. And a second inspection means for inspecting the state of formation of the resist by using the image of the third color light source. It is a test that can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows arrangement | positioning of the illuminating device and camera of the automatic test | inspection apparatus which show one Embodiment of this invention.
The figure which shows the arrangement | positioning state of LED of the 1st color light source in the same form.
Fig. 3 is a diagram showing an image of a pad acquired using each color light source in the same form.
Fig. 4 is a diagram showing an image of a resist acquired using each color light source in the same form.
Fig. 5 is a diagram showing an image of a resist under pattern obtained by using each color light source in the same form.
6 is a functional block diagram in the same form;
FIG. 7 is a diagram showing a histogram when inspecting a pad or a resist in the same form; FIG.
FIG. 8 is a diagram showing a histogram when inspecting a contour of a pad in the same form; FIG.
Fig. 9 is a diagram illustrating cluster processing of a resist under pattern in the same embodiment.
10 is a flowchart of inspection in the same embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described with reference to drawings. The inspection apparatus 1 of the printed circuit board 7 in this embodiment is the illumination device 2 which irradiates light to the printed circuit board 7 mounted on the stage, and the illumination device 2 The camera 6 which receives the reflected light reflected from the printed board 7 as the light from the pad, and the pad 71 and the resist 72 formed on the surface of the printed board 7 from the image acquired by the camera 6. 1st inspection means 81 thru | or 3rd inspection means 83 (refer FIG. 6) etc. which test the formation state, etc., etc. are comprised. And it is characterized in that the lighting device 2 is provided with a red LED 32 disposed at a first angle (ie, angle of bright field illumination) that is specularly reflected with respect to the optical axis of the camera 6. With a one-color light source 3, a second color light source 4 which is a green fluorescent lamp disposed at an angle different from the first angle, and a blue LED arranged in an acute angle with respect to the optical axis of the camera 6 The third color light source 5 is provided, and the wound 71b and the scar 71c and the like of the surface of the pad 71 are inspected by the image of the first color light source 3 of the red LED 32. At the same time, the formation state of the contour 71a of the pad 71 and the like can be inspected by the green diffused light, and the formation state of the resist 72 can be inspected by the dark field illumination by the blue LED. It would be. Hereinafter, the inspection apparatus 1 in this embodiment is demonstrated in detail.

First, the printed circuit board 7 used as the inspection target is placed on a stage using a conveying means (not shown), and is conveyed to the lower portion of the lighting device 2 or the camera 6 in that state. Then, the light of each color is irradiated simultaneously from the illuminating device 2, and the light reflected by the printed circuit board 7 is acquired by the camera 6 among them. Here, as the camera 6 for acquiring an image, a color filter which separates into a plurality of wavelengths such as RGB by a color filter is used, and the color camera etc. which receive each light by a CCD element and convert it into an electrical signal are used.

As shown in Fig. 1, the lighting device 2 includes a first color light source 3 made of a red LED 32, a second color light source 4 made of a fluorescent lamp which is green diffused light, and a blue LED. It is comprised including the 3rd color light source 5 which comprised.

Among these, the red LED 32 which is the 1st color light source 3 is arrange | positioned so that a plurality of rows (two columns in FIG. 2) may be formed along the longitudinal direction of the elongate board | substrate 31, The angles of the optical axes of the red LEDs 32 in each row are crossed. That is, the red LED 32 of the first row is mounted so that the optical axis is inclined toward one end side along the longitudinal direction of the substrate, and the red LED 32 of the second row has It is attached so that the optical axis may incline toward the other end side along the longitudinal direction. By arranging the red LEDs 32 in this way, the thin red light from both directions is irradiated within the range of the width in the shorter direction of the elongated substrate 31. At this time, the red light irradiated from the first color light source 3 is strongly reflected from the exposed copper and gold pads 71 of the printed board 7 and from the red LED 32 crossing each other. The light can be received by the camera 6 in a state where the contrast is strengthened with respect to various direction wounds 71b and other marks 71c by light. Further, when the reflected light, which is such bright field illumination, is received by the camera 6, the light is strongly reflected at the outline 71a of the pad 71 (Fig. 3 (a)), whereby the deviation of the luminance becomes large and clear. The outline image cannot be obtained. Moreover, also regarding the discoloration of the pad 71, the dispersion | variation in surface luminance is large, and the image suitable for inspection cannot be acquired. For this reason, the light from the first color light source 3 is used as illumination for inspecting the minute wound 71b and the scar 71c of the pad 71.

On the other hand, the second color light source 4, which is a green fluorescent lamp, is provided at a different angle from the red LED 32, which is bright field illumination. Here, as shown in FIG. 1, the 2nd color light source 4 is attached so that it may incline to the red LED 32 side with respect to the normal line of the printed circuit board 7, and this makes the surface of the pad 71 bright. The image can be acquired in one state. In addition, the second color light source 4 is provided with an umbrella 41 on the side opposite to the printed circuit board 7 so as to diffuse light in a wider range than the first light source, and diffuses light from a fluorescent lamp in a wide range. I'm going to let you. In addition, in the case where light is diffused in a wide range, in addition to providing an umbrella 41, a diffusion plate may be provided on the entire surface of the second color light source 4 to diffuse the light. By irradiating such a green diffused light to the printed circuit board 7, as shown in FIG.3 (b), the outline 71a of the exposed pad 71 is able to acquire the clear image. . In other words, when diffused illumination is used, it is difficult to see the small scratches 71b and the scars 71c on the pad surface, but light deviation is small for the outline 71a of the pad 71, so that a clear image can be obtained. It is possible. Moreover, since S / N ratio becomes high also about the discoloration of the pad 71, the image favorable for inspection can be acquired. For this reason, the green diffused light is used as illumination for detecting the contour 71a of the pad 71 for the first purpose. In addition, although green light is used as the second color light source 4 here, in the case of using red light, the reflectance of the exposed pad 71 becomes high, and the light is greatly reflected by the outline 71a of the pad 71. This is because it becomes difficult to extract the outline 71a image. On the other hand, when the green light is used as the second color light source 4, since the reflectance at the pad 71 becomes small, the image of the outline 71a of the pad 71 can be clearly extracted, and the resist When 72 is green or blue, since the reflectance can be increased in green light, it becomes possible to acquire an image suitable for inspection of the resist 72. In addition, the fluorescent lamp is used as the diffusion light because in the case of the fluorescent lamp, since the wavelength of red or blue is included in addition to the wavelength of green, even when the resist 72 is reddish brown or blue, it is possible to cope with this. to be. In addition, although the green fluorescent lamp is used here, when inspecting the formation state of the resist 72 other than the outline 71a of the pad 71, the blue fluorescent lamp corresponds to the color of the resist 72. You may use it. However, since blue fluorescent light is weaker in the red wavelength range than green fluorescent light, it is preferable to use green fluorescent light when inspecting the red resist 72.

Next, as shown in FIG. 1, the blue LED which is the 3rd color light source 5 is acutely angled with respect to the optical axis of the camera 6 arrange | positioned at the diagonal direction (namely, in the normal direction of the printed circuit board 7). On the camera 6 side). By irradiating blue light from the third color light source 5 as dark field illumination, diffused reflection light of rough portions formed on the surface of the printed board 7 can be obtained. Here, as a rough part, the thin part or thin part of the resist 72, the omission of the resist 72, the printing bleeding of silk, etc. are mentioned. On the other hand, when the pad 71 is irradiated with light in dark field illumination, most of the light is specularly reflected from the surface of the pad 71 to obtain a clear image such as a wound 71b or a scar 71c on the surface of the pad. It becomes impossible. For this reason, the dark field illumination from the blue LED is to be used as illumination when inspecting the state of formation of the resist 72. In addition, although blue LED is used here, when the blue diffused illumination is used as the 2nd color light source 4, a green LED different from this is used.

The light from the first color light source 3 to the third color light source 5 is irradiated to the printed board 7 at the same time, and the reflected light is acquired by the camera 6. When this camera 6 acquires this image, it separates into the wavelength of RGB area | region by the color filter which is a separating means, and it stores in the storage means 80 as another image by CCD elements, respectively.

Next, a method of inspecting the formation state of the printed circuit board 7 based on the image separated by the wavelength of the RGB region in this way will be described.

<Pad surface inspection>

First, in the first inspection means 81 in FIG. 6 which is a functional block, the area of the pad 71 that is exposed is extracted based on the image acquired by the green diffused illumination, and the area is shrunk. And in the predetermined | prescribed inner area | region from the outline 71a of the pad 71, it examines by the bright field illumination from the red LED 32 which is the 1st color light source 3. As shown in FIG. Specifically, based on the second color image, which is green diffused illumination, an image within a range of a predetermined luminance width corresponding to the luminance value of the pod 71 is extracted, and the image is subjected to shrink processing for several pixels. Then, the image of the contracted area is extracted from the image by the red LED 32, and a luminance value histogram for each RGB in the area is generated (Fig. 7A). At this time, when there are more than a predetermined number of pixels having a luminance value lower than the first threshold value a1 or when there are more than a predetermined number of pixels having a luminance value higher than the second threshold value a2, the wound 71b is present. It is determined that other marks 71c and the like exist, and an output of "defect" is output. In addition, here, it is made to determine whether the pad 71 has a predetermined width by the number of pixels having a luminance value lower than the first threshold value a1 or the number of pixels having a luminance value higher than the second threshold value a2. The branched part may be judged as a wound 71b or a scar 71c, and it may be determined whether it is good or bad depending on its length or area.

Moreover, in the 1st test | inspection means 81, in addition to the wound 71b and the scar 71c of the pad 71, the discoloration of a pad surface is also examined. When this discoloration inspection is performed, similarly, based on the image by green diffused illumination, the image within the predetermined | prescribed brightness | luminance width corresponding to the brightness | luminance value of the pad 71 is extracted, and the image is shrunk for several pixels. This time, a luminance value histogram for each RGB is generated from the image of the contracted region obtained by the green diffused illumination, and it is determined how many pixels having luminance values other than the predetermined RGB luminance values exist. At this time, when a predetermined number or more of pixels other than the predetermined luminance value exist, it is determined that the area is discolored and the determination is made as "defect".

<Contour inspection of pad>

Next, the second inspection means 82 inspects the state of formation of the contour 71a of the pad 71. When the state of formation of the contour 71a is inspected, similarly to the first inspection means 81, an image within a predetermined luminance width corresponding to the luminance value of the pad 71 based on the image by the green diffused illumination. Extract Shrinkage and expansion are performed on the extracted area of the pad 71, and a ring-shaped blue image area enclosed by the shrinkage area and the enlarged area of the pad 71 as shown in the upper figure of FIG. A luminance histogram is generated with the axis in the direction of the normal outside of the contraction region. In addition, in the upper figure of FIG. 8, the outline 71a of the pad 71 is shown by the thick solid line. The quality of the contour 71a is determined according to how far the inflection point of the luminance histogram is in the pixel along the radial direction from the portion where the contour 71a is shrunk from the position of the inflection point of the luminance histogram in the reference data. do. That is, when the inflection point of the histogram is a predetermined value or more away from the position of the inflection point of the reference data, it is determined that the projection and the flaw are present as defective.

<Inspection of Resist 72>

In addition, in the third inspection means 83, the resist 72 is inspected. In the case of inspecting the resist 72, the region of the resist on the pattern 72 and the region of the resist 72 on the substrate are separated based on the image of the dark field illumination of the blue LED which is the third color light source 5. Each area is inspected based on the blue image. When the pattern image resist 72 and the substrate image resist 72 are separated from the blue image, an image having a luminance width corresponding to the pattern image resist 72 is extracted from the obtained blue image and the substrate image resist ( An image of luminance width corresponding to 72) is extracted. At this time, when the blue LED arranged under the camera is used, since the wavelength is relatively short, the refractive index in the resist 72 becomes large, and light enters in a direction substantially perpendicular to the inside. Since the vertical light is reflected in a direction substantially perpendicular to the pattern, and the light is refracted in the direction of the camera, a brighter image with a higher amount of light can be obtained. Then, the disconnection 74, the short, etc. of the pattern 73 under the resist are inspected based on the image of the resist 72 on the pattern by the blue light. In the case of inspecting the disconnection 74, the shot, or the like, cluster processing for arranging regions having substantially the same luminance in the inspection region is performed, and the number of cluster regions in the inspection region and the cluster region in the reference image. By comparing the number of. At this time, when disconnection 74 occurs in the inspection region, as shown in FIG. 9, the number of cluster regions (the region of "1" in FIG. 9) corresponding to the luminance of the pattern 73 under the resist is shown. Since it becomes larger than the number of cluster areas in a reference image, it can be determined that the disconnection 74 is caused. On the other hand, when a short is generated in the inspection region, the cluster region corresponding to the luminance of the resist 72 on the substrate is divided, so that the cluster region ("0" region in FIG. 9) of the resist color on the substrate is a reference. It becomes larger than the number of cluster area | regions in an image. It can be judged that a short is generated by this. In addition, although it is made here to determine the presence or absence of the disconnection 74 and the short by cluster process, you may determine the disconnection 74 and the short by other methods.

Next, when inspecting the application state of the resist 72 on the substrate, the extracted resist under pattern 73 is expanded, and the region of the resist 72 except for the vicinity of the boundary of the pattern 73 is inspected. . The reason why the vicinity of the boundary of the pattern 73 is excluded is that the application state of the resist 72 becomes unstable at the boundary portion of the pattern 73. In the case of inspecting the application state of this resist 72, since the light is irradiated to the resist 72 by the dark field illumination by a blue LED, if there exists ink ink, it will receive the reflected light to the part. In addition, when the ink is left out or the like, the reflected light on the boundary portion can be received. Based on the number of pixels having a predetermined luminance or more in the reflected light, it is determined that there are ink smears or flaws, and it is determined that the defect is defective depending on the size.

<Inspection of Pattern 73 Under Resist>

Moreover, in this 3rd inspection means 83, the formation state of the resist 72 can also be test | inspected also by the green diffused illumination which is the 2nd color light source 4. As shown in FIG. When the state of formation of the resist 72 is inspected by the green image as the second color light source 4, the entire resist 72 is inspected without separating the portion of the pattern 73. Thereby, it becomes possible to test peeling and foreign matter adhesion in the whole resist 72 including the boundary of the resist under pattern 73 which could not be examined in the blue image. In addition, since the green image is diffused illumination, an image due mainly to reflection by surface roughness can be obtained without being affected by some unevenness of the surface, and the presence or absence of the resist under pattern 73 and the resist under pattern 73 The image which is hard to be influenced by the unevenness | corrugation of the outline 71a of ()) can be acquired. Based on the image thus obtained, the degree of ink depends on how many pixels having a luminance equal to or smaller than the predetermined luminance value a3 in FIG. Judge the presence or absence of flaws.

Next, the flow of the inspection in the inspection apparatus 1 of the printed circuit board 7 comprised in this way is demonstrated with reference to FIG.

First, when inspecting the formation state of the surface of the printed board 7, the stage is moved to the lower side of the lighting device 2, and the light of the first color light source 3 to the third color light source 5 is simultaneously (Step S1). The reflected light is separated into a plurality of wavelengths such as RGB by a color filter, and each is received by the CCD element of the camera 6 (step S2), and the image of the first color light source 3 and the second color light source ( The storage means 80 is stored as an image of 4) and an image of the third color light source 5.

First, based on the image of the second color light source 4 (that is, the image by green diffused illumination), an image corresponding to the luminance width of the pad 71 is extracted (step S3), and the image is shrunk. The inner region of the pad 71 is extracted (step S4). Then, a luminance value histogram is generated for the inner region of the pad 71 in the image of the first color light source 3 (that is, the image by the red LED 32) (step S5), and the wound or the scar is removed. It is determined that the predetermined number of pixels having a luminance lower than the first threshold a1 exists for inspection (step S6), and is also defective even when a predetermined number of pixels having a luminance higher than the second threshold a2 exists. Is determined.

In parallel with this, a luminance value histogram is generated from the image of the contracted region obtained by the green diffuse illumination (step S7), and it is determined how many pixels having luminance values other than the predetermined RGB luminance values exist. . At this time, when a predetermined number or more of pixels other than the predetermined luminance value exist, it is determined that the color change area is defective (step S8).

Next, to examine the formation state of the outline 71a of the pad 71, an image within a predetermined luminance width corresponding to the luminance value of the pad 71 is extracted based on the image by the green diffused illumination. (Step S4). Shrinkage and expansion are performed on the region of the extracted pad 71, and a ring-shaped green image region surrounded by the contraction region and the enlarged region is extracted (step S9), and the region shown in FIG. A luminance histogram with respect to the radial direction is generated from the contracted area of the pad 71 as shown in step S10. Then, whether or not the inflection point in the histogram falls within a predetermined range of the inflection point position in the histogram in the reference data is determined whether the contour 71a is successful (step S11).

Moreover, this time, based on the image of the dark field illumination of the blue LED which is the 3rd color light source 5, in order to test the formation state of the resist 72, the resisted pattern, etc., the area | region of the resist 72 on a pattern. The regions of the resist 72 on the substrate are separated (step S12), and each region is inspected based on a blue image. At this time, when inspecting the disconnection 74, the short, etc. of the pattern 73 under a resist based on the image of the resist 72 on a pattern, the cluster process which arranges the area | region which has substantially the same luminance in an inspection area. (Step S13), the presence or absence of the disconnection 74 or the short is determined by comparing the number of cluster areas in the inspection area with the number of cluster areas in the reference image (step S14).

In addition, when inspecting the application state of the resist 72 on a base material, the extracted resist lower pattern 73 is expanded, and the area | region of the resist 72 except the boundary vicinity of the pattern 73 is extracted (step S15). ), The pixels having a predetermined luminance or more in the area are summed, and it is determined that there are ink spots or flaws depending on the number (step S16).

In addition, when the formation state of the resist 72 is also examined by the green diffused illumination which is the 2nd color light source 4, the whole resist 72 is examined (step S17). Also in inspection by this green diffused illumination, the number of pixels of the part with high brightness which generate | occur | produces by the rough part of a surface is totaled, and the ink smudges, a flaw, the presence of a foreign material etc. are judged according to the number.

Thus, according to the said embodiment, in the inspection apparatus 1 of the printed circuit board 7 which examines the formation state of the pad 71 and the resist 72 formed in the printed circuit board 7, with respect to the camera 6, The first color light source 3 disposed at the first angle to be brightfield illumination, the second color light source 4 to be diffused illumination by fluorescent lamps, and the third angle of darkfield illumination to the camera 6. A third color light source 5 disposed thereon, and using the light from the first color light source 3 to the third color light source 5 to take an image of the printed board 7 with the camera 6 First inspection means 81 for inspecting the presence or absence of a wound 71b on the pad surface by using the image of the first color light source 3 and the image of the second color light source 4 that is the diffused illumination. The formation state of the resist 72 using the second inspection means 82 for inspecting the formation state of the pad 71 contour 71a and the image of the third color light source 5 Because to have a third detecting means 83 for use, it becomes possible to perform inspection in accordance with the optimum properties of each inspection area.

Moreover, since the 3rd color light source 5 was provided in the direction which forms an acute angle with the camera 6 provided in the diagonal direction with respect to the printed circuit board 7, the light with extremely low surface roughness like the pad 71 etc. is acquired. It is possible to eliminate diffused reflection light from the resist 72 of the resist 72 having a very large surface roughness, and to effectively inspect the state of formation of the resist 72.

Further, the first color light source 3 is a red LED 32 light source, the second color light source 4 is a green light source or a blue light source, and the third color light source 5 is a second color light source. Since it was set as the blue LED light source or green LED light source different from (4), it becomes possible to acquire the image of the wound 71b, the scar 71c, etc. of the pad 71 correctly, and like the resist 72, For a color close to green or blue, the surface image can be accurately acquired by dark or dark dark field illumination.

In addition, when inspecting the formation state of the resist 72 by the 3rd inspection means 83, since the pattern 73 area | region was inspected also using the image of the said 2nd color light source 4, the light source of each color The portion of the resist 72 which could not be inspected at can be inspected by a light source of a different color.

In addition, this invention can be implemented in various aspects, without being limited to the said embodiment.

For example, in the said embodiment, although the red LED 32 was provided as the 1st color light source 3 by crossing, you may provide a lens etc. in front of a light source, and may implement substantially parallel light.

In the above embodiment, a green fluorescent lamp is used as the second color light source 4, but a diffuser plate may be attached to the green LED to realize diffused light.

In addition, in the said embodiment, although blue LED was provided as the 3rd color light source 5, it can also implement | achieve by a blue fluorescent lamp.

In addition, red here means the wavelength within the predetermined width which makes red (first wavelength) a basis, green means the wavelength within the predetermined width which is based on green (second wavelength), and blue means blue ( The wavelength within a predetermined width based on the third wavelength).

In addition, although the said embodiment is made to irradiate RGB light simultaneously to the printed circuit board 7, you may irradiate light individually for every RGB and acquire an image separately.

Moreover, the 1st test | inspection means 81 in the said embodiment inspects the wound 71b of the pad 71, the scars 71c, discoloration, etc., and in the 2nd test means 82 of the pad 71, Although the outline 71a is examined by the 3rd inspection means 83, the application | coating state of the resist 72, the formation state of the pattern 73 under the resist 72, etc. are examined, but these individual inspection methods are mentioned above. The test may be performed according to an algorithm other than the method shown in the form.

1. Automatic inspection device
2 lighting equipment
3. First color light source
31 ...
32 ... red LED
4 ... second color light source
41 Umbrella
5 ... third color light source
6 ... camera
7. ... printed board
71 pad
71a
71b ... wound
71c
72 ... resist
73 pattern
74.
81 ... first inspection means
82 ... second inspection means
83 ... third inspection means
9 ... Memory

Claims (6)

In the inspection apparatus of the printed circuit board which examines the formation state of the pad and resist which were formed in the printed circuit board,
A first color light source disposed at a first angle of brightfield illumination with respect to the camera,
A second color light source which is a diffused light by a fluorescent lamp,
A third color light source disposed at a third angle of darkfield illumination with respect to the camera,
Take an image of a printed board with a camera using the light from the first color light source to the third color light source,
First inspection means for inspecting a pad surface for damage using an image of said first color light source;
Second inspection means for inspecting a state of formation of a pad outline by using an image of a second color light source that is the diffuse illumination;
And a third inspection means for inspecting the state of formation of the resist by using the image of the third color light source. The method according to claim 1,
And the third color light source is provided in an acute angle with a camera provided in an inclined direction with respect to the printed board. The method according to claim 1,
Inspection of a printed board wherein the first color light source is a red LED light source, the second color light source is a green light source or a blue light source, and the third color light source is an index blue LED light source or a green LED light source different from the second color light source Device. The method according to any one of claims 1 to 3,
And the third inspecting means inspects the pattern region using the image of the second color light source. The method according to claim 1,
On the basis of the image of the third color light source, the resist on the substrate and the region of the resist under pattern are separated using a predetermined luminance threshold, and the region of the resist under pattern is expanded, and An apparatus for inspecting a printed circuit board for inspecting a coating state of a resist on a substrate. The method according to claim 1,
On the basis of the image of the third color light source, a region of the resist and the resist under pattern on the substrate are separated using a predetermined luminance threshold, and presence or absence of disconnection or short with respect to the region of the resist under pattern is determined. Inspection apparatus of the printed circuit board which let you inspect.

Images