JP2010048602A - Printed board inspection device and printed board inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed board inspection device and printed board inspection method capable of accurately detecting flaws formed on an inner surface of a through hole. <P>SOLUTION: The printed board inspection device includes: a reflection part 23 disposed on a first face of a through hole 12a of a print board 12; a lighting means 31 for lighting the through hole 12a from a second face of the print board 12; an imaging device 32 for photographing the through hole 12a from the second face of the print board 12; and a defect inspection means 33 for inspecting a defect of the through hole 12 based on image information of the through hole 12a photographed by the imaging device 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printed circuit board inspection apparatus and inspection method for inspecting defects in through holes formed in a printed circuit board.

  As this type of printed circuit board inspection apparatus, for example, illumination means for irradiating light to the through hole from a predetermined angle with respect to the formation direction of the through hole of the substrate, and in the formation direction of the through hole on the opposite side of the illumination means An external appearance inspection apparatus and an external appearance inspection method for a substrate have been proposed which perform an external appearance inspection of a through hole such as a through hole using an external appearance inspection apparatus provided with an imaging means and an image winning means installed at a predetermined angle. (For example, refer to Patent Document 1).

Also, a printed circuit board placing means, a conveying means for conveying the printed circuit board so as to pass through a predetermined speed inspection position, a line-shaped irradiation means for irradiating a through-hole wall surface formed on the printed circuit board located at the inspection position, The optical axis is at a predetermined angle with respect to the central axis direction of the through hole on the opposite side of the printed circuit board from the line irradiation unit so as to capture an image of the wall surface of the through hole irradiated through the line irradiation unit A diffusing means for diffusing the light emitted from the line irradiating means is arranged in the vicinity of the incident side of the through hole of the light emitted from the line irradiating means at the inspection position. A through hole wall surface defect inspection apparatus for a printed circuit board has been proposed (see, for example, Patent Document 2).
JP 2007-177847 A JP 2007-127486 A

  In both of the conventional examples described in Patent Documents 1 and 2, illumination light is incident on the through hole of the printed circuit board from the lower surface side at a predetermined angle, and the reflected light transmitted through the through hole is imaged by the imaging means. In this way, since the through-hole defect is inspected, the illumination light is directly reflected by tilting the incident angle of the illumination light and tilting the optical axis of the imaging device to an angle different from the incident angle of the illumination light. The inner wall of the through hole illuminated with the illumination light is imaged by the imaging device so as not to enter the imaging device, thereby obtaining imaging data.

However, when the illumination unit and the imaging unit are arranged so as to sandwich the printed circuit board, when the diameter of the through hole is relatively large, an image of the wall surface of the through hole can be captured relatively clearly. There is an unsolved problem that it becomes difficult to obtain a clear image of the wall surface of the through hole as the diameter of the hole decreases. In addition, when the defect formed in the through hole is in a so-called pseudo-disconnection state in which there is a fine defect that is recognized as normal in the continuity inspection, it is difficult to determine the fine defect from the image data. There is an unsolved problem of being.
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and a printed circuit board inspection apparatus and inspection method capable of accurately detecting a flaw formed on the inner wall surface of a through hole. It is intended to provide.

  The printed circuit board inspection apparatus according to claim 1 of the present invention is a reflection unit disposed on one surface side of a through hole of the printed circuit board, and an illumination unit that illuminates the through hole from the other surface side of the printed circuit board, An image pickup device for picking up an image of the through hole from the other surface side of the printed circuit board and a defect inspection means for inspecting a through hole defect based on image information picked up by the image pickup device are provided.

According to a second aspect of the present invention, there is provided a through-hole defect inspection apparatus for a printed circuit board according to the first aspect, wherein the imaging device is a line-type imaging device and relatively moves the printed circuit board and the imaging device relative to each other. It is characterized by having a moving means.
Furthermore, a printed circuit board inspection apparatus according to a third aspect is characterized in that, in the invention according to the first aspect, the imaging device is constituted by an area-type imaging device.

Furthermore, the printed circuit board inspection apparatus according to a fourth aspect of the present invention is the invention according to any one of the first to third aspects, further comprising a close-contact holding unit that closely attaches the reflection portion to the back surface side of the through hole of the printed circuit board. It is characterized by that.
Still further, the printed circuit board inspection apparatus according to claim 5 is the invention according to claim 4, wherein the reflection portion is formed of a porous sheet, and the close-contact holding means is configured to pass the printed circuit board through the porous sheet. It is characterized by comprising a printed circuit board holding table for sucking and holding.

According to a sixth aspect of the present invention, there is provided the printed circuit board inspection apparatus according to the fourth aspect, wherein the contact holding means includes a mounting table for mounting the printed circuit board through the reflecting portion, and a surface of the printed circuit board. A transparent body placed on the side, and pressure contact means for pressing the transparent body against the placement table via the printed circuit board and the reflection portion.
Furthermore, the printed circuit board inspection apparatus according to claim 7 is the invention according to claim 4, wherein the contact holding means includes at least two pairs of conveying means having a pair of upper and lower conveying rollers that convey the printed circuit board while sandwiching the printed circuit board. It is characterized by having a configuration in which a reflecting portion is disposed at a predetermined interval and in close contact with the back side of the printed circuit board between the two sets of conveying means.

Furthermore, the printed circuit board inspection apparatus according to claim 8 is the invention according to any one of claims 1 to 7, wherein the defect inspection means includes a through-hole image of a reference printed circuit board in which regular through-holes are formed. The through-hole defect is inspected by comparing with a through-hole image captured by the imaging device.
Still further, in the printed circuit board inspection apparatus according to claim 9, in the invention according to any one of claims 1 to 7, the defect inspecting unit uses the same shape of the through-hole image information formed on the printed circuit board. It is characterized by being configured to inspect through-hole defects by comparison.

A printed circuit board inspection apparatus according to a tenth aspect is the invention according to any one of the first to ninth aspects, wherein the imaging apparatus is configured to output color image information with a high degree of defect selection. It is characterized by.
Furthermore, the printed circuit board inspection apparatus according to claim 11 is characterized in that, in the invention according to any one of claims 1 to 9, the imaging apparatus is configured to output grayscale image information. .

Furthermore, the printed circuit board inspection method according to claim 12 is illuminated by illuminating the printed circuit board from the other surface side with an illuminating means in a state where the reflection portion is disposed on the one surface side of the through hole of the printed circuit board. In addition, the imaging apparatus includes an imaging step of imaging the through-hole with an imaging device from the other surface side of the printed circuit board, and a defect inspection step of inspecting a through-hole defect based on the captured through-hole image information. .
Still further, a printed circuit board inspection method according to a thirteenth aspect is characterized in that, in the invention according to the twelfth aspect, the reflection portion is held in close contact with the through hole back surface side of the printed circuit board.

A printed circuit board inspection method according to a fourteenth aspect is the invention according to the twelfth or thirteenth aspect, wherein the imaging device is a line-type imaging device, and the printed circuit board and the imaging device are relatively moved by relative movement means. It is characterized by picking up images of through holes.
Furthermore, a printed circuit board inspection method according to a fifteenth aspect is characterized in that, in the invention according to the twelfth or thirteenth aspect, the imaging device is an area-type imaging device.

Furthermore, the printed circuit board inspection method according to claim 16 is the invention according to any one of claims 12 to 15, wherein the defect inspection step includes a through-hole image of a reference printed circuit board in which regular through-holes are formed. A through-hole defect is inspected by comparing with a through-hole image captured by the imaging device.
Still further, in the printed circuit board inspection method according to claim 17, in the invention according to any one of claims 12 to 16, the defect inspection step uses the same through-hole image information formed on the printed circuit board. The comparison is characterized by inspecting through-hole defects.

According to the present invention, the reflecting part is arranged on one surface side of the printed circuit board to be inspected, and the illuminating means for illuminating the through hole and the imaging device for imaging the illuminated through hole are arranged on the other surface side. Because the through-hole defect is inspected based on the image information of the through-hole imaged by the imaging device, the through-hole defect can be accurately detected from the luminance information of the through-hole image without directly capturing the image of the through-hole defect. The effect that can be done.
Moreover, since it is only necessary to inspect the presence or absence of through-hole defects based on the image information of the through-holes imaged by the imaging device, it is not necessary to examine through-hole defects one by one. Can do.
Here, as the image pickup apparatus, any of a line type image pickup apparatus and an area type image pickup apparatus can be applied, and as the image information, any of color image information and multi-gradation gray scale image information can be applied.

Hereinafter, the actual form of the present invention will be described with reference to the drawings.
FIG. 1 is an external perspective view showing a printed circuit board inspection apparatus according to the first embodiment of the present invention. In FIG. 1, a printed circuit board inspection apparatus 10 has a mounting table 13 on which a printed circuit board 12 is mounted at an intermediate position in the vertical direction of a case body 11 and is slidable in a horizontal state back and forth. Further, the printed circuit board inspection apparatus 10 has a support arm 15 provided on the front plate 14 on the upper side of the mounting table 13, and a display device 16 configured by, for example, a liquid crystal display is supported at the tip of the support arm 15. ing. Further, the printed circuit board inspection apparatus 10 is provided with an input device 17 for inputting printed circuit board shape data and the like below the mounting table 13.

  As shown in FIG. 2, the mounting table 13 includes a plurality of suction grooves 21 having a V-shaped cross section formed at predetermined intervals in the printed circuit board mounting region on the upper surface, and a predetermined amount at the bottom of each suction groove 21. A suction hole 22 connected to the vacuum suction source is opened at an interval. Further, a white porous sheet 23 as a reflecting portion is installed on the printed circuit board placement surface 13 a of the printed circuit board 12 of the placement table 13, and the printed circuit board 12 is sucked and held through the porous sheet 23. The warp of the printed circuit board 12 is corrected, and the porous sheet 23 is brought into close contact with one surface of the printed circuit board 12, for example, the back surface 12a. Here, the width of the suction groove 21 is selected so that the porous sheet 23 is not separated from the bottom surface of the printed circuit board 12 during suction.

Then, the mounting table 13 is moved by a sliding mechanism (not shown), and the printed board mounting position where the printed board mounting surface 13a is exposed to the outside through the opening 11a of the case body 11 shown in FIG. It is possible to slide between the inspection position in the case body 11 on the rear side.
As shown in FIG. 2, the inspection position in the case body 11 faces the other surface side, that is, the front surface side of the printed circuit board 12 placed on the placement table 13, and moves in the moving direction of the placement table 13. A line illuminating device 31 is provided as illuminance means for irradiating irradiation light obliquely to the through hole 12a of the printed circuit board 12 inclined by a predetermined angle in the counterclockwise direction with respect to the vertical plane VF orthogonal thereto. Yes. A line type color imaging device 32 that images the through hole 12a of the printed circuit board 12 illuminated by the line illumination device 31 is disposed so as to face the line illumination device 31 with the vertical plane VF interposed therebetween. .

  Then, the image data of the printed circuit board 12 captured by the line type color imaging device 32 is input to the image processing device 33 as shown in FIG. As shown in FIG. 3, in addition to the line-type color imaging device 32, the image processing device 33 includes an illumination device 31, a reference image data memory 34, an external storage device 35, a mounting table reciprocating drive mechanism 37, and a display device. 16 and the input device 17 are connected.

The reference image data memory 34 captures the surface of the non-defective printed circuit board 12 to be a reference image with the line-type color image pickup device 32, and is a through target to be inspected for the red (R) component of the reference color image information obtained by this imaging. It is a memory that stores density values at the center of the hole.
The external storage device 35 includes a hard disk, a flexible disk, an optical disk, a flash memory, and the like, and can store a large amount of image data as will be described later.

The mounting table reciprocating drive mechanism 37 controls the movement of the mounting table 13 at a constant speed at a relatively low speed on the forward path from the printed circuit board attachment / detachment position to the inspection position, and the return path from the inspection position to the printed circuit board attachment / detachment position. Is controlled at a relatively high speed.
In the image processing device 33, printing is performed according to the image processing program stored in the external storage device 35 based on the color image information captured by the line-type color imaging device 32 that images the printed circuit board 12 conveyed by the mounting table 13. A defect in the through hole 12a formed in the substrate 12 is inspected.

  As described above, the detection of the defect of the through hole 12a is performed with the illumination device 31 on the other surface of the printed circuit board 12 in a state where the white porous sheet 23 as the reflection portion is in close contact with the one surface of the printed circuit board 12. In addition, by arranging the imaging device 32 and imaging the through-hole 12a with the line-type color imaging device 32, the presence or absence of a defect in the through-hole 12a is accurately determined from the image data output from the line-type color imaging device 32. It becomes possible to do.

  As a result of various experiments, the present inventors brought a reflective portion such as a white sheet into close contact with one surface of the printed circuit board 12, and the through-hole 12 a was connected to the other surface side of the printed circuit board 12 with the illumination device 31. It was discovered that the illuminated through hole 12a was imaged by the imaging device 32 disposed on the other surface side of the printed circuit board 12, and the presence or absence of a defect could be accurately identified from the imaging data.

  That is, a printed circuit board 12 having a thickness of 1.1 mm as shown in FIG. 4 having normal through holes 12a is prepared. Of the 150 normal through holes 12a having a diameter of 0.5 mm, for example, FIG. For example, the No. 83, no. 84, no. 95 and No. As shown in the enlarged view in FIG. The through hole 12a represented by 100 was drilled with a drill, and all the plated portions of the through hole were removed to form a test printed board.

  Using this test printed circuit board, a white sheet is adhered to one side, for example, the back side, and the other side, for example, the front side is a flat having an illumination device and a line type color imaging device corresponding to FIG. Using the head scanner, the test printed circuit board was imaged by the line type color image pickup device 32 while moving the illumination device and the line type color image pickup device at a predetermined speed with the test printed circuit board in the horizontally long state as shown in FIG. At this time, color image information at the center position of all 150 through holes of φ0.5 mm (position where the reflection sheet on the back side of the substrate is shown) is extracted, and the extracted color image information is extracted on the RGB color space. FIG. 5 shows the result of the plotting for all the through holes 12a. 5A shows the density value of the red (R) component, FIG. 5B shows the density value of the green (G) component, and FIG. 5C shows the density value of the blue (B) component. Represent each.

  As is apparent from FIG. 5, since the copper plating is formed on the inner wall surface of the through hole 12a, the red (R) component in the color image information imaged by the line type color imaging device is shown in FIG. As shown in FIG. 4, the normal through hole 12a having no scratch on the inner wall surface has a red (R) component concentration value within the range of 90 to 120, as indicated by “◯”. No. which is a through hole 12a in which there is a scratch on a non-walled surface. 83, no. 84, no. 95 and No. No. 120, as indicated by “●”, falls within the range of 79 to 62 lower than the minimum concentration value 90 of the red (R) component of the normal through-hole 12a, and further, No. 120 having no plating on the inner wall surface. For 100 through holes 12a, the density value of the red R component was about 10 which was even lower. From this result, the red (R) component at the center position of the through hole 12a in the color information obtained by imaging the printed circuit board with the line type color imaging device in the state where the reflection sheet is arranged on the opposite side to the line type color imaging device. It was found that the presence or absence of scratches on the inner wall surface of the through hole 12a can be accurately determined by extracting.

  Incidentally, among the color image information output from the line-type color imaging device, for the blue (B) component, as shown in FIG. 5B, the density value of the blue (B) component is normal for the normal through hole 12a. 35 to 60, and the inner wall surface has scratches. 84, the density value of the blue (B) component of the through hole 12a is 36, 95, the density value of the blue (B) component of the through hole 12a is 34, No. 95. 83 and no. 100, the density value of the blue (B) component of the through hole 12a is 29, no. The density value of the blue (B) component of 120 through holes 12a is 28, and the density value of the blue (B) component is in the range of 35 to 40, and the normal through hole 12a and the through hole 12a having scratches on the inner wall surface Accurate discrimination is difficult.

  Similarly, among the color image information output from the line-type color imaging device, the green (G) component is the density value of the green (G) component of the normal through-hole 12a as shown in FIG. No. having a flaw on the inner wall surface. 84, the green (G) component density value in the through hole 12a is 31, 95, the density value of the green (G) component of the through hole 12a is 28, no. The density value of the green (G) component of the 120 through-holes 12a is 24, no. 83 and no. The density value of the green (G) component in 100 through holes 12a is 22. From this result, no. 84 and no. It is difficult to clearly distinguish 95 through holes from normal through holes 12a.

  On the other hand, the test printed circuit board 12 described above is a vertically long state shown in FIG. 6B rotated 90 degrees counterclockwise from the horizontally long state shown in FIG. 6A, and further rotated 90 degrees counterclockwise. In each of the horizontally long state shown in FIG. 6 (c) and the vertically long state shown in FIG. 6 (d) rotated 90 degrees counterclockwise, a white sheet is adhered to the lower surface side of the printed circuit board 12 in the same manner as described above. 7A to 7D show the results of measuring the density value of the red (R) component at the center position of the φ0.5 mm through hole 12a in the color image information captured by the line type color imaging device of the flat head scanner. ). Of these, FIG. 7 (a) is the same as FIG. 4 (a) described above, and is shown again for comparison with other figures.

  As is apparent from FIG. 7, when the test printed circuit board 12 is rotated 90 degrees counterclockwise from the horizontally long state of FIG. 6A to the vertically long state as shown in FIG. 6B, FIG. As shown in FIG. 5B, the density value of the red (R) component of the normal through hole 12a and the No. Although it is closest to the density value of the red (R) component of the 84 through-hole 12a, it can be easily distinguished from each other. ) And (d), it is possible to easily discriminate between the density value of the red (R) component of the normal through hole 12a and the through hole 12a having a flaw on the wall surface that is not present. In particular, when there is no plating on the wall surface without the through hole 12a, the density value of the red (R) component is a small value extremely close to “0”, and it is possible to reliably determine the presence or absence of a defect.

  Further, in FIGS. 7C and 7D, No. A thorough examination of the 23 through holes 12a revealed that the inner wall surface of the through hole 12a was not scratched, but the resist was adhered to the inner wall surface. In this case, the through-hole defect does not occur, but the density value of the red (R) component contained in the color image information captured by the line-type color imaging device is normal due to the adhesion of the resist to the inner wall surface of the through-hole 12a. It has been demonstrated that the concentration decreases to a level that can be accurately discriminated from the concentration value of the through hole 12a.

  As a result, when there is no scratch or foreign matter attached to the inner wall surface of the through-hole 12a, the illumination sheet disposed on the front surface side of the printed circuit board 12 is present due to the presence of the reflective sheet in close contact with the back surface side of the printed circuit board 12. When the light emitted from the apparatus is irregularly reflected in the through-hole 12a, the density value of the red (R) component of the color image information is obtained when the image is picked up by a line-type color image pickup apparatus that is also arranged on the surface side of the printed circuit board 12. Get higher. On the other hand, when the inner wall surface of the through hole 12a is scratched or a foreign matter that absorbs light is attached, a part of the irradiation light or reflected light is absorbed by the scratch or the foreign matter, and line type color imaging is performed. The density value of the red (R) component of the color image information output from the apparatus will decrease. Therefore, it is possible to accurately detect a flaw or a copper plating defect in the through-hole 12a based on the density value of the red (R) component included in the color image information when the through-hole 12a of the printed circuit board 12 is imaged by the line type color imaging device. Can do.

  Further, the above-described test printed circuit board 12 is turned upside down, and a reflection sheet is brought into close contact with the surface of the test print circuit board 12, and the back surface of the test print circuit board 12 shown in FIG. However, as shown in FIG. 9, the density value of the red (R) component included in the color image information is similar to the above-described FIG. 5 and FIG. It was found that there was a clear difference between the case where no plating was present on the inner wall surface, and even when the resist was attached to the inner peripheral surface of the through hole 12a, it was possible to differentiate from the normal through hole 12a.

  Furthermore, when a reflective sheet is closely attached to the back side of the test printed circuit board 12 described above, an illumination device and a digital color camera are arranged on the front side, and the test printed circuit board 12 is imaged from the front side with the digital color camera. As shown in FIG. 10, the density value of the red (R) component included in the color image information is the same as in the case of imaging with the above-described flat-type color imaging device of the flat head scanner. It was possible to clearly discriminate from defective through holes with poor plating.

  On the other hand, as shown in FIG. 11, an incomplete substrate in a copper plated state with a thickness of 1.5 mm and a through hole 42 having a diameter of 0.25 mm and a through hole 43 having a diameter of 1.3 mm is prepared as a test substrate 41. For the through hole 42 of the test substrate 41, no. 27 and no. No. 42 was scratched on the inner wall of the through hole. No. 65 is a state in which no plating is present, and the through hole 43 is also No. 65. For No. 4, the inner wall of the through hole was scratched, and the others were normal through holes.

  The test substrate 41 is imaged by the above-described line type color imaging device of the flat head scanner, and color information at the center position of all the through holes 42 is extracted from the image data of the imaged test substrate 41 to obtain the RGB color. The results of plotting the density values of the red (R) component, the green (G) component, and the blue (B) component for all the through holes 42 having a diameter of 0.25 mm are shown in FIGS. Shown in (c).

  As is apparent from FIG. 12, the through hole 42 having a diameter of 0.25 mm is also indicated by “●” in which the inner wall surface of the through hole has a flaw in the concentration value of the red (R) component shown in FIG. Through hole 42 No. 27 and no. No. 42 is a value sufficiently smaller than the density value of the normal through hole 42 indicated by “◯”, and similarly, the No. of the through hole 42 in which no copper plating is present on the inner wall surface indicated by “●”. The density value of 65 was extremely small, and it was proved that the presence or absence of defects on the inner wall surface can be accurately determined for the through hole 42 having a diameter of 0.25 mm.

  On the other hand, for the green (G) component, as shown in FIG. 27 and no. Although it is difficult to determine the presence or absence of defects in the through-hole 42 of No. 42, no. For the 65 through holes 42, the density value of the green (G) component is sufficiently smaller than the normal through hole 42, and it is possible to sufficiently determine whether or not copper plating exists on the inner wall surface. Has been demonstrated.

Furthermore, for the blue (B) component, as shown in FIG. 27 and no. No. 42 in which there is no copper plating on the through hole 42 and the inner wall surface. It is difficult to differentiate between the density value of 65 and the density value of the normal through hole 42, and it is difficult to determine the presence or absence of defects in the through hole 42.
As a result, when the unfinished board with the entire copper plating is used as the test board 41, the red color (R) of the color image information captured by the line-type color imaging device 32 is used for the through hole 42 having a diameter of 0.25 mm. ) By extracting the component, it is possible to accurately detect the presence or absence of a defect on the inner wall surface of the through hole 41.

  The through hole 43 having a diameter of 1.3 mm on the test substrate 41 is red (in RGB space at the center position of each through hole 43 of the color image information captured by the above-described line type color imaging device of the flat head scanner. When the density values of the R, green (G), and blue (B) components are plotted, the results are as shown in FIGS. 13A, 13B, and 13C, and the red (R) component and the green (G) component. In each of the blue and blue (B) components, a normal through-hole 43 represented by “◯” and a no. When there is a clear difference in density value between the four through-holes 43 and the through-hole diameter is large, any of the red (R), green (G), and blue (B) components It was demonstrated that the presence or absence of defects in the hole 43 can be accurately determined.

  As described above, the lighting device and the line are arranged on the other surface side of the printed circuit board 12 in a state in which a white or other reflective sheet is closely attached to one surface of the printed circuit board 12 so that the illumination light from the illumination device does not leak outside. An area type color image pickup device such as a color image pickup device or a digital camera is arranged, a through hole illuminated by an illumination device is picked up by the image pickup device, and an inner wall surface of the through hole 12a is scratched based on the picked up color image information It is possible to accurately detect the defective through hole 12a in which there is a defect or there is a defective plating adhesion. In particular, by extracting a color component corresponding to the color of the inner peripheral surface of the through hole 12a, it is possible to accurately determine the presence or absence of a through hole defect.

For this reason, in this embodiment, the density value of the red (R) component of the color image information in the non-defective printed circuit board 12 having normal through holes and the color of the printed circuit board 12 to be inspected by visual observation using a microscope or the like. By comparing the density value of the red 8 (R) component of the image information, a through hole defect inspection is performed based on the difference in density value.
For this reason, the image processing apparatus 33 first prepares a printed circuit board that is determined to be non-defective by visual inspection using, for example, a microscope, and places the printed circuit board on the mounting table 13.

  In this state, the reference data collection process shown in FIG. 14 is executed with the lighting device 31 turned on. In this reference data collection process, first, at step S1, a constant speed movement command at a low speed is output to the inspection table side to the mounting table reciprocating drive mechanism 37, and then the process proceeds to step S2 where the line type A color imaging command for the printed circuit board 12 is output to the color imaging device 32.

  Next, the process proceeds to step S3, and the color image information for each line output from the line type color imaging device 32 is sequentially read, and then the process proceeds to step S4 to determine whether or not the printed circuit board 12 has reached the inspection end position. If the printed circuit board 12 has not reached the inspection end position, the process returns to step S3, and when the inspection end position is reached, the process proceeds to step S5 to stop imaging with respect to the line type color imaging device 32. Outputs a command.

  Subsequently, the process proceeds to step S6, and the density value of, for example, the red (R) component corresponding to the center position of the through hole 12a having the same diameter to be inspected is extracted from the color image data read from the line type color imaging device 32. Then, the extracted density value is stored in the reference image data memory 34 in association with an identification number that is a serial number individually assigned to the through hole to be inspected.

  Next, the process proceeds to step S7, and a return path drive command toward the printed circuit board attachment / detachment position is output to the placement table reciprocating drive mechanism 37. Next, the process proceeds to step S8, where the placement table 13 is attached to / detached from the printed circuit board. It is determined whether or not the position has been reached. If the printed board mounting / removing position has not been reached, the process waits until the printed board mounting / removing position is reached. After outputting a stop command to the mechanism 37, the process is terminated.

Next, the printed circuit board 12 to be inspected is placed on the placement table 13, and in this state, the image processing device 33 performs the through-hole defect inspection process shown in FIG.
In this through-hole defect inspection process, first, in steps S11 to S16, the same process as the reference data collection process described above is performed to correspond to the center position of the through-hole 12a to be inspected of the printed circuit board 12 to be inspected. For example, the density value of the red (R) component is extracted, and the extracted density value is stored in a predetermined storage area of the external storage device 35 in association with the identification number assigned to the through hole.

  Next, the process proceeds to step S17, in which the density value of the red (R) component corresponding to the identification number of each through hole 12a in the reference printed circuit board stored in the reference image data memory 34 is read and the external storage device 35 is read. The density value of the red (R) component corresponding to the identification number of each through hole 12a of the printed circuit board 12 to be inspected stored in the predetermined storage area is read out.

  Next, the process proceeds to step S18, the variable n representing the rank of the identification number is set to “1”, and then the process proceeds to step S19, where the density of the red (R) component of the reference printed circuit board for the nth identification number. It is determined whether or not the deviation ΔR obtained by subtracting the density value of the red (R) component of the printed circuit board to be inspected from the value is greater than or equal to a predetermined threshold value Rth, and when ΔR <Rth, the through hole 12a to be inspected is internally It is determined that there is no defect, and the process proceeds to step S20.

In this step S20, for example, a flag of “0” indicating normality is written in the determination result entry area provided corresponding to the corresponding identification number stored in the predetermined storage area of the external storage device 35. The process proceeds to step S21.
In this step S21, it is determined whether or not the determination process has been completed for all the identification numbers. If there is an identification number that has not been subjected to the determination process, the process proceeds to step S22 and the current variable n is set to “1”. After calculating a new variable n incremented by "", the process returns to step S19.

  On the other hand, when the determination result in step S19 is ΔR ≧ Rth, it is determined that the through hole 12a corresponding to the corresponding identification number has an internal defect, the process proceeds to step S23, and the predetermined value of the external storage device 35 is determined. For example, a flag “1” indicating an abnormality is written in the determination result entry area provided corresponding to the corresponding identification number stored in the storage area, and then the process proceeds to step S21.

  If the determination result of step S21 is determined for all the identification numbers, the process proceeds to step S24, where the determination result storage area corresponding to the identification number of the predetermined storage area of the external storage device 35 is stored. It is determined whether or not the “1” flag is stored. If the “1” flag is not stored, it is determined that the printed circuit board is a normal printed circuit board, and the process proceeds to step S25. After the guidance information is displayed on the display device 16, the through-hole defect inspection process is terminated, and when the determination result of step S24 is a flag “1” stored in the determination result storage area, it is determined that the printed circuit board is defective. Then, the process proceeds to step S26, where the guidance information indicating that the printed circuit board is defective and the identification number of the defective through-hole are displayed on the display device 16, and then the process proceeds to step S26. To end the Horu defect inspection process. The process of FIG. 15 corresponds to the defect inspection means.

Next, the operation of the above embodiment will be described.
First, a through hole is examined using a microscope or the like, and a normal printed circuit board 12 having no defect in each through hole is used as a reference printed circuit board, and the white porous sheet 23 of the mounting table 13 with its surface as the upper surface side. Place in a predetermined position on the top. In this state, the vacuum suction source is operated, and the reference printed board 12 is sucked and held in a state where the porous sheet 23 is brought into close contact with the back surface side of the reference printed board 12 in the suction groove 21. Thereby, the curvature of the printed circuit board 12 is also corrected.

Next, the reference data collection process of FIG. 14 is started by pressing a predetermined start button on the image processing apparatus 33.
In this reference data collection process, an outward constant speed movement command for moving the mounting table 13 to the inspection position is output to the mounting table reciprocating drive mechanism 37, and the mounting table 13 is moved to the rear inspection position ( Step S1).
Next, by outputting a color imaging command to the line type color imaging device 32 (step S2), the line type color imaging device 32 images the surface of the reference printed circuit board 12, and the color of the reference printed circuit board 12 is obtained. Output image information.

  The color image information output from the line-type color imaging device 32 is sequentially read for each line (step S3), and the reading of the color image information is repeated until the reference printed circuit board 12 reaches the inspection end position (step S4). When the printed circuit board reaches the inspection end position, an imaging stop command is output to the line type color imaging device 32 (step S5), and imaging of the printed circuit board 12 by the line type color imaging device 32 is stopped.

Thereafter, the density value of the red (R) component corresponding to the center position of the through hole 12a is extracted from all the through holes 12a having a predetermined diameter to be inspected from the read color image information, The extracted density value of the red (R) component is stored in the reference image data memory 34 in association with the identification number (step S6).
Thereafter, a return path drive command is output to the mounting table reciprocating drive mechanism 37 (step S7), whereby the mounting table 13 is returned to the front substrate attaching / detaching position, and the mounting table 13 is returned to the substrate attaching / detaching position. Then, after outputting a stop command to the mounting table reciprocating drive mechanism 37, the reference data collecting process is terminated.

As described above, in the reference data collection process, the red (R) component is extracted from the color image information for all the through holes 12a having the same diameter to be inspected of the reference printed circuit board 12 having the normal through holes 12a, and the inspection target is obtained. The density value of the red (R) component at the center position of the through hole 12a is stored in the reference image data memory 34 in association with the identification number.
When the density value of the red (R) component at the center position of the through-hole 12a to be inspected for the reference printed circuit board is stored in the reference image data memory 34 in this way and the collection process is completed, the printed circuit board 12 to be inspected. Is placed on the porous sheet 23 of the placing table 13 with its front side facing up. In this state, the vacuum suction source is operated to hold the inspection target printed circuit board 12 on the mounting table 13 with the porous sheet 23 in close contact with the back surface thereof.

Thereafter, by pressing a predetermined start button, the image processing device 33 executes the through-hole defect inspection process shown in FIG.
In this through-hole defect inspection processing, processing similar to the data collection processing of the reference printed circuit board 12 described above is performed, and the printed circuit board 12 to be inspected is imaged by the line-type color image pickup device 32, and the color image information is subjected to image processing. The density value of the red (R) component at the center position of the through hole 12a to be inspected is read from the color image information by the apparatus 33, and the extracted density value of the red (R) component is stored in the external storage device 35 as a predetermined value. Store in the storage area (steps S11 to S16).

Thereafter, the density value of the red (R) component of the first identification number of the reference printed circuit board 12 is read from the reference image data memory 34 and the first printed circuit board 12 of the inspection target printed circuit board 12 is read from a predetermined storage area of the external storage device 35. The density value deviation ΔR is calculated by reading the density value of the red (R) component of the identification number and subtracting the latter from the former, and determines whether or not the calculated density value deviation ΔR is equal to or greater than a predetermined threshold Rth ( Step S19).
At this time, when the inspection target through-hole 12a of the inspection target printed circuit board 12 is normal, the density value deviation ΔR becomes smaller than the predetermined threshold value Rth (ΔR <Rth), and it is determined as normal, and the process proceeds from step S19 to step S20. Then, the flag “0” is written in the determination result storage area of the corresponding identification number in the external storage device 35.

  On the other hand, if the inner wall surface of the inspection target through hole 12a of the inspection target printed circuit board 12 is scratched, plating adhesion is defective, or resist is adhered, the red color (R) at the center position of the inspection target through hole 12a. Concentration values of the components are clearly smaller than when normal. For this reason, by performing the determination in step S19, the density value deviation ΔR becomes sufficiently larger than the predetermined threshold value Rth, and it is determined that there is a through-hole defect, and the process proceeds from step S19 to step S23. A flag “1” is written in the radius result storage area of the identification number.

  Thereafter, the density value deviation ΔR of the red (R) component with respect to the inspection target through hole 12a of the reference printed circuit board 12 is sequentially calculated for all the inspection target through holes 12a of the inspection target printed circuit board 12 while sequentially incrementing the identification number. Then, by determining whether or not the calculated concentration deviation ΔR is equal to or less than the predetermined threshold value Rth, it is possible to accurately detect the presence or absence of a defect on the inner wall surface of the through hole 12a.

When the defect determination process is completed for all of the inspection target through holes 12a, the process proceeds from step S21 to step S24, and is “1” among the flags of the identification numbers stored in the external storage device 35. It is determined whether or not a flag exists. If there is no flag that is “1” and all the flags are “0”, it is determined that the printed circuit board is normal and the display device 16 is informed. Guidance information indicating normality is displayed (step S25).
On the other hand, if there is a flag “1” among the identification numbers stored in the external device 35, it is determined that a through-hole result exists, and the display device 16 receives the through-hole. Guidance information indicating that a result has occurred is displayed, and an identification number of the defective through hole is displayed.

  As described above, according to the first embodiment, the through hole 12a is connected to the lighting device 31 from the other surface side while the white or other reflective sheet 23 is in close contact with the one surface side of the printed circuit board 12 to be inspected. While illuminating, the line-type color imaging device 32 images the through-hole from the other surface side, and the color component close to the color of the inner wall surface of the through-hole 12a in the captured color image information, that is, the inner wall surface of the through-hole 12 Is plated with copper, the concentration value of the red (R) component of the through hole 12a to be inspected is extracted. Then, by comparing the density value of the extracted red (R) component with the density value of the red (R) component of the through hole 12a of the normal reference printed circuit board, the presence or absence of a defect in the through hole 12a to be inspected can be accurately determined. Can be determined.

In addition, it is only necessary to extract the density value of the through hole to be inspected from the image information of the printed circuit board 12 to be inspected, which is imaged by the line type color imaging device 32, and the defect image actually generated in the through hole 12a is extracted. The inspection is not carried out one by one, and complicated image editing processing such as special image analysis is not required, so that through-hole defect inspection per printed circuit board can be performed in a short time.
In the first embodiment, the case where the line-type color image pickup device 32 is applied as the image pickup device has been described. However, the present invention is not limited to this. A red transmission filter may be provided in the part so that only the red component is imaged.

  Moreover, in the said 1st Embodiment, although the case where the porous sheet 23 was applied as a reflection member was demonstrated, it is not limited to this, As shown in FIG. Surrounding the outer side of the printed circuit board 12 to be inspected and the porous sheet 23, an elastic convex part 51 slightly projecting from the printed circuit board 12 is disposed, and the upper surface of the printed circuit board 12 and the elastic convex part 51 are covered. As a configuration in which the sheet-like transparent body 52 is disposed, by adsorbing the sheet-like transparent body 52, the adhesiveness with the porous sheet 23 can be secured while correcting the warp of the printed circuit board 12. Good.

Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, a printed circuit board inspection device 60 is provided in the middle of the transport line that transports the printed circuit board 12 in the horizontal direction.
In this printed circuit board inspection apparatus 60, the conveyed printed circuit board 12 is transported by a pair of upper and lower transport rollers 61 and 62 disposed at a predetermined interval in the horizontal direction, and at least between the transport rollers 61 and 62, A reflecting member 63 made of a synthetic resin material such as tetrafluoroethylene whose upper surface contacting the lower surface side of the printed circuit board 12 is a white reflecting portion is supported and disposed by an elastic supporting member 64 such as a compression coil spring. Have a configuration. Further, the line type illumination device 31 and the line type color imaging device 32 similar to those of the first embodiment described above are arranged on the opposite side of the printed board 12 from the reflection member 63.

  The elastic support member 64 supports the reflection member 63 so that the upper surface of the reflection member 63 does not protrude from the upper surface 12 of the printed circuit board 12 when the printed circuit board 12 is not present between the transport rollers 61 and 62. On the upper surface of the reflection member 63, an inclined engagement surface 63a that engages with the end surface of the printed circuit board 12 and moves the reflection member 63 downward against the elastic support member 64 is formed.

  According to the second embodiment, the upper surface of the reflection member 63 protrudes into the conveyance path of the printed circuit board 12 in a state where the printed circuit board 12 does not exist between the conveyance rollers 61 and 62. When the printed circuit board 12 is transported by this, the end surface of the printed circuit board 12 engages with the inclined engaging surface 63a of the reflecting member 63, so that the reflecting member 63 descends against the elastic support member 64, and the upper surface thereof is elastic. The support member 64 is pressed against the lower surface of the printed circuit board 12. For this reason, the lower surface of the printed circuit board 12 and the upper surface of the reflecting member 63 are in sliding contact with each other, and the through hole 12 a formed in the printed circuit board 12 is blocked by the reflecting portion on the upper surface of the reflecting member 63.

  Accordingly, the inner wall surface of the through hole 12a is illuminated by the line type illumination device 31 arranged on the opposite side of the printed board 12 with respect to the reflection member 63, and the illuminated through hole 12a is illuminated by the line type color imaging device 32. In this case, the color image information of the printed circuit board 12 is output from the line-type color imaging device 32, and this color image information is supplied to the image processing device 33 as in the first embodiment, so that each through Color image information at the center position of the hole 12a is extracted, and the presence / absence of defects on the inner wall surface of the through hole is determined by the density value of, for example, the red (R) component of the extracted color image information as in the first embodiment. It can be determined accurately.

Next, a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, when the printed circuit board 12 is imaged by the line type color imaging device 32 in the first and second embodiments described above, as shown in FIG. A line type color image pickup device 32 is arranged in the center, and the upper surface of the printed circuit board 12 is picked up in a line within a predetermined viewing angle range of the line type color image pickup device 32. At this time, the image of the through hole 12a imaged by the line type color image pickup device 32 becomes a circular image as shown in FIG. 18C for the through hole 12a directly below the line type color image pickup device 32. The image of the through-hole 12a becomes an elliptical image shown in FIG. 18 (d) in which the short axis gradually shortens from the position toward the left and right ends.

For this reason, the density value of each component in the color image RGB space of the central through hole 12a becomes a high value in the central through hole 12a, and becomes a smaller value from the end toward the end.
For this reason, when the density values of the through hole 12a at the center and the through hole 12a at the end are compared, it is impossible to accurately determine the defect.
For this reason, as shown in FIG. 18B, color image information of the printed circuit board 12 imaged by the line type color imaging device 32 is set to a band-shaped unit area having a predetermined width in a direction orthogonal to the transport direction of the printed circuit board 12. Then, RGB of the color image information at the center position of the through hole 12a in the color image information of the reference printed circuit board 12 and the inspection target printed circuit board imaged by the line type color imaging device 32 with respect to the through hole 12a group existing in the unit area. By comparing the density values of the color components close to the color of the inner wall surface of the through hole 12a in space, it is possible to more accurately determine the presence or absence of a defect in the through hole 12a. In this case, the narrower the unit area, the better the defect through hole discrimination accuracy. However, if the unit area is too narrow, the inspection time will take longer, so the width should be set according to the required defect discrimination accuracy. Is preferred.

  In the third embodiment, the case where the color image information of the reference printed circuit board and the inspection target printed circuit board is compared for each unit area has been described. However, the present invention is not limited to this. By comparing the density values of color components close to the color of the inner wall surface of the through hole 12a in the RGB space for the same shape of the through hole 12a in the unit area for each printed circuit board to be inspected without using imaging information. The through hole 12a having a density value lower than the other density values can also be determined to be defective.

Next, a fourth embodiment of the present invention will be described with reference to FIGS.
In the fourth embodiment, instead of the case where the printed circuit board 12 is imaged by the line type color image pickup device 32, a line type grayscale image pickup device having a predetermined number of gradations is applied.
That is, in the fourth embodiment, as shown in FIG. 19, in the first embodiment described above, the line-type color imaging device 32 is a line type that can output grayscale image information of a predetermined gradation, for example, 256 gradations. The monochrome imaging device 70 is changed.

  When the line-type monochrome imaging device 70 is applied as described above, the mounting table of the printed circuit board inspection apparatus 10 according to the first embodiment using the test printed circuit board 12 similar to that of the first embodiment described above. The line-type monochrome image pickup device while illuminating the upper surface of the test printed circuit board 12 with the line-type illumination device 31 by moving the placement table 13 to the inspection position at a predetermined speed while being placed on the 13 porous sheets 23. The test printed circuit board 12 is imaged at 70, and, for example, 8-bit grayscale imaging information output from the line-type monochrome imaging device 70 is stored in a predetermined storage area of the external storage device 35. At this time, the first grayscale image information when the test printed circuit board 12 is mounted and imaged at the center position in the direction orthogonal to the moving direction of the mounting table 13 that can image the bottom with the line type monochrome imaging device 70. And the second gray scale imaging information when the image is placed at the right end position in the direction orthogonal to the moving direction of the mounting table 13 where the bottom portion cannot be imaged at all by the line-type monochrome imaging device 70. The data was stored in a predetermined storage area of the storage device 35.

  For each of the first and second grayscale imaging information stored in the external storage device 35, after performing blurring processing once using image editing software, noise removal processing is performed once, and First image processing in which the minimum value filtering process is performed four times, and second image processing in which the minimum value filtering process is performed four times after the maximum value filtering process is performed once in the same manner using image editing software. I did it. Here, the minimum value filtering process is used to make it easier to extract the darkest pixel in the through-hole region included in the grayscale imaging information.

  Then, the first image processing is performed on each of the first and second gray scale imaging information, and the result of extracting the luminance at the center position of each through hole 12a is shown in FIGS. In this first image processing, when only the darkest pixel in the through-hole area is compared, there is a possibility that false information may be generated due to variations in brightness or noise during imaging, so blur processing is performed for the purpose of diminishing variations. And noise removal filter processing.

  However, when the first image processing is performed on the first grayscale image information obtained by placing the test printed circuit board 12 at the center position in the direction orthogonal to the moving direction of the placement table 13, the first image processing is performed. As shown in (a), there is a clear difference between the brightness of the normal through hole 75 represented by “♦” and the brightness of the defective through hole 76 having scratched the inner wall surface represented by “□”. Although it is difficult to discriminate between the normal through hole 75 and the defective through hole 76, the test printed circuit board 12 is placed on the right end in the direction orthogonal to the moving direction of the placement table 13 and imaged. When the first gray scale image information of 2 is subjected to the first image processing, as shown in FIG. 19B, the brightness of the normal through hole 75 represented by “♦” and the inner wall surface represented by “□” Scratched defect Clear difference is obtained in the brightness of the hole 76, it is possible to determine the normal through-hole 75 and the defect through hole 76 accurately.

In addition, FIGS. 19C and 19D show the results of performing the second image processing for each of the first and second grayscale imaging information and extracting the luminance at the center position of each through hole 12a. In the second image processing, a minimum value filtering process is performed for the purpose of axial use for pixels that are particularly darkened by the first image processing described above.
Therefore, when the second image processing is performed on the first grayscale image information obtained by placing the test printed circuit board 12 at the center position in the direction orthogonal to the moving direction of the placement table 13, the second image processing is performed. As shown in FIG. 19 (c), it is possible to differentiate between the brightness of the normal through hole 75 represented by “♦” and the brightness of the defective through hole 76 having scratched the inner wall surface represented by “□”. A normal through hole 75 and a defective through hole 76 can be distinguished.

  Further, when the first image processing is performed on the second gray scale image information obtained by placing the test printed circuit board 12 on the right end in the direction orthogonal to the moving direction of the placement table 13, the first image processing is performed (see FIG. 19). As shown in d), a clear difference is obtained between the brightness of the normal through-hole 75 represented by “♦” and the brightness of the defective through-hole 76 scratched on the inner wall surface represented by “□”. The through hole 75 and the defective through hole 76 can be accurately discriminated.

In each of the above-described embodiments, the case where the printed circuit board 12 to be inspected is moved with respect to the illumination device 31 and the line-type imaging devices 32 and 70 has been described. However, the present invention is not limited to this. The printed circuit board 12 to be fixed may be fixed, and the illumination device 31 and the line type imaging devices 32 and 70 may be moved together.
Further, in each of the above embodiments, the case where the line-type imaging device is applied has been described. An imaging device may be applied. In this case, since one printed circuit board is divided into a plurality of areas and imaged, defect inspection is performed based on imaging information obtained by imaging the area image, and defect inspection is easy because the imaging range is narrow. In addition, when a through hole defect is detected in the inspection result, the through hole having the defect can be imaged again and reinspected, and the defect detection accuracy can be further improved.

Furthermore, in each said embodiment, although the case where the porous sheet 23 and the reflection member 63 were applied as a reflection part was demonstrated, it is not limited to this, A sheet etc. which are easy to reflect illumination lights, such as white A reflective member can be applied.
Furthermore, in each of the above embodiments, the case where the through-hole defect inspection process shown in FIG. 15 is executed has been described. However, the present invention is not limited to this, and the color image information of the reference printed board and the measurement target printed board is obtained. Any through-hole defect inspection process can be applied as long as the structure can inspect through-hole defects by comparison.

Further, in each of the above embodiments, the case where the defect inspection is performed while the lighting device 31 is turned on has been described. However, the present invention is not limited to this, and the lighting device 31 is turned on at the start of the inspection. You may make it turn off the illuminating device 31 at the time of completion | finish.
Further, in each of the above embodiments, the case where the shape of the through hole 12a is circular has been described. However, the present invention is not limited to this, and even when the through hole 12a has a special shape such as a long hole shape, the same size is the same. Defect detection can be performed by performing color imaging on a through-hole in the same manner as described above.

1 is an external perspective view showing a printed circuit board inspection apparatus according to a first embodiment of the present invention. It is typical sectional drawing of the mounting table of FIG. 1, an illuminating device, and a line type color imaging device. It is a block diagram which shows the image processing apparatus which can be applied to this invention. It is a surface view which expands and shows a part of printed circuit board used as inspection object. It is a graph showing the density value of the red (R) component, the green (G) component, and the blue (B) component of the color imaging information of the through hole to be inspected of the printed circuit board to be inspected in FIG. It is a surface view which shows the rotation position of the printed circuit board used as inspection object. It is a graph showing the density value of the red (R) component of the inspection object through hole of the color imaging information at the rotation position of FIG. It is a back view of the printed circuit board used as inspection object. It is a graph showing the density | concentration value of the red (R) component of the inspection object through hole of the color image information of FIG. It is a graph showing the density | concentration value of the red (R) component of the inspection object through hole of the color image information imaged with the digital color camera of FIG. It is a surface view which shows an incomplete printed circuit board. 12 is a graph showing density values of a red (R) component, a green (G) component, and a blue (B) component of color imaging information of a small-diameter through hole that is an inspection target of the color image information in FIG. 11. 12 is a graph showing density values of a red (R) component, a green (G) component, and a blue (B) component of color imaging information of a large-diameter through-hole to be inspected for color image information in FIG. 11. It is a flowchart which shows an example of the reference | standard data collection process procedure performed with an image processing apparatus. It is a flowchart which shows an example of the through-hole defect inspection process procedure performed with an image processing apparatus. It is typical sectional drawing of the mounting table, the illuminating device, and the line type color imaging device which show the modification of the 1st Embodiment of this invention. It is typical sectional drawing of the mounting table which shows the 2nd Embodiment of this invention, an illuminating device, and a line type color imaging device. It is explanatory drawing which shows the 3rd Embodiment of this invention. It is typical sectional drawing of the mounting table which shows the 4th Embodiment of this invention, an illuminating device, and a line type color imaging device. It is a graph which shows the brightness in the inspection object through hole of the gray scale image information in the inspection object printed circuit board in the fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Printed circuit board inspection apparatus, 12 ... Printed circuit board, 12a ... Through-hole, 13 ... Mounting table, 16 ... Display apparatus, 23 ... Porous sheet, 31 ... Line illumination apparatus, 32 ... Line type color imaging device, 33 ... Image processing device 34 ... reference image memory 35 ... external storage device 37 ... mounting table reciprocating drive mechanism 70 ... line type monochrome imaging device

Claims (17)

  Reflecting portion arranged on one surface side of through hole of printed circuit board, illumination means for illuminating said through hole from the other surface side of said printed circuit board, and imaging of said through hole from the other surface side of said printed circuit board A printed circuit board inspection apparatus comprising: an imaging device that performs inspection; and a defect inspection unit that inspects through-hole defects based on image information of the through-holes captured by the imaging device.   The printed circuit board inspection apparatus according to claim 1, wherein the imaging apparatus includes a line-type imaging apparatus, and includes a relative movement unit that relatively moves the printed circuit board and the imaging apparatus.   The printed circuit board inspection apparatus according to claim 1, wherein the imaging apparatus is an area-type imaging apparatus.   4. The printed circuit board inspection apparatus according to claim 1, further comprising an adhesion holding unit configured to closely attach a reflection portion to a back surface side of the through hole of the printed circuit board. 5.   The said reflection part is formed with a porous sheet, The said close_contact | adherence holding means is comprised by the printed circuit board holding table which adsorbs and hold | maintains the said printed circuit board through the said porous sheet. Printed circuit board inspection equipment.   The contact holding means includes a mounting table for mounting the printed circuit board via the reflecting section, a transparent body for mounting on the surface side of the printed circuit board, and the transparent body through the printed circuit board and the reflecting section. The printed circuit board inspection apparatus according to claim 4, further comprising pressure contact means that press-contacts the mounting table.   The close-contact holding means arranges at least two pairs of conveying means having a pair of upper and lower conveying rollers that convey the printed circuit board while holding the printed circuit board at a predetermined interval, and the back surface of the printed circuit board is located between the two sets of conveying means. The printed circuit board inspection apparatus according to claim 4, wherein the printed circuit board inspection apparatus has a configuration in which a reflection portion that is in close contact with the side is disposed.   The defect inspection means is configured to inspect a through-hole defect by comparing a through-hole image of a reference printed board on which a regular through-hole is formed and a through-hole image captured by the imaging device. The printed circuit board inspection apparatus according to claim 1, wherein   8. The defect inspection means is configured to inspect through-hole defects by comparing pieces of identical through-hole image information formed on a printed circuit board. The printed circuit board inspection apparatus according to claim 1.   The printed circuit board inspection apparatus according to claim 1, wherein the imaging apparatus is configured to output color image information having a high degree of defect selection.   The printed circuit board inspection apparatus according to claim 1, wherein the imaging apparatus is configured to output grayscale image information.   In a state where the reflective portion is arranged on one surface side of the through hole of the printed circuit board, the printed circuit board is illuminated with illumination means from the other surface side, and the illuminated through hole is illuminated from the other surface side of the printed circuit board. A printed circuit board inspection method comprising: an imaging step for imaging with an imaging device; and a defect inspection step for inspecting a through-hole defect based on the captured through-hole image information.   The printed circuit board inspection method according to claim 12, wherein the reflection portion is held in close contact with a through hole rear surface side of the printed circuit board.   14. The printed circuit board inspection according to claim 12, wherein the image capturing apparatus is configured by a line-type image capturing apparatus, and the through-hole is imaged while the printed circuit board and the image capturing apparatus are relatively moved by a relative moving unit. Method.   The printed circuit board inspection method according to claim 12, wherein the imaging apparatus is an area-type imaging apparatus.   The defect inspection step inspects a through-hole defect by comparing a through-hole image of a reference printed board on which a regular through-hole is formed and a through-hole image captured by the imaging device. Item 16. The printed circuit board inspection method according to any one of Items 12 to 15.   The defect inspection step inspects a through-hole defect by comparing pieces of identical through-hole image information formed on a printed circuit board. Printed circuit board inspection method.

Images