JP5096940B2 - Inspection method and apparatus for printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspecting method for a printed wiring board in which a wire short including a false short can be automatically, easily and accurately decided, and a device therefor. <P>SOLUTION: The method includes steps of: fixing a workpiece 3 to a workpiece mount table 17 when inspecting whether a circuit constitution portion of the workpiece 3 has a short; determining a suitable position where an image of the circuit constitution portion 13 is focused by continuously changing the position of an imaging means for imaging the circuit constitution portion 13 of the workpiece 3; imaging circuit constitution portions 13 at a plurality of positions together at a time by the imaging means 19; performing binarization processing for displaying only the circuit constitution portions 13 of the captured image in one of two colors; subjecting the binarization-processed image after the binarization processing to expansion processing for expanding the circuit constitution portions 13 until the circuit constitution portions 13 are short-circuited to each other at a distance between the circuit constitution portions 13 which is less than a reference value; and acquiring the color area of the circuit constitution portions 13 having been expanded and deciding whether the color area is within a reference value at which the inspection is passed. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a printed wiring board inspection method and apparatus, and more particularly, to a printed wiring board inspection method and apparatus for connecting an electronic component mounted on a printed wiring board including an FPC and a printed wiring board with a wire.

  Conventionally, wire bonding is well known as one of the techniques for mounting electronic components on a printed wiring board. Since wire bonding is a method of mounting directly on a printed wiring board without using solder, the mounting area is reduced, which contributes to higher density of the printed wiring board.

  One inspection item for wire bonding is a short-circuit inspection between wires. It goes without saying that when adjacent wires are short-circuited, it is not good, but even when the wires are not short-circuited, a current flows between adjacent wires if the distance between the wires is extremely narrow, It is generally known that a so-called pseudo short circuit occurs.

  As a method for inspecting wire short circuits, visual inspection using a microscope by an operator has been generally performed. Is a heavy burden on the people. In addition, since the miniaturization of the wiring pattern has been further advanced in recent years, the limit of the visual inspection has been pointed out.

  For this purpose, automatic inspection methods and apparatuses have been introduced, and inspection methods based on pattern matching and three-dimensional measurement have been developed.

  Pattern matching is a method that is suitably used for detecting foreign objects, discoloration, shape defects, and the like. In other words, the pattern matching means that a non-defective product image is stored in advance in a program, and the image obtained by imaging the work to be inspected is compared with the non-defective product image to obtain “good” when the degree of coincidence is greater than a predetermined value. This is a technique for identifying a case where this is not the case as “bad”. That is, this pattern matching is performed according to the following procedure.

(1) A product that is known to be good in advance is imaged as a template image.

(2) By moving the XY stage, the wire portion to be inspected of the workpiece is aligned with an imaging device such as a CCD camera.

(3) The entire wire portion is focused by a method such as changing the height of the CCD camera.

(4) The wire part is imaged, and the captured image is compared with the template image. If the degree of coincidence exceeds a predetermined value, it is determined as “good”, and the others are determined as “bad”.

(5) The above procedures (1) to (4) are repeated until the determination of all wires is completed.

  As an automatic wire inspection method, a three-dimensional shape inspection as disclosed in Patent Document 1 is known. This inspection method has a length measurement function, detects the apex of the wire while changing the height between the XY stage and the camera by a minute distance, and then changes each height while changing the minute distance in the reverse direction. A three-dimensional wire shape is obtained by imaging at the height and performing image processing for extracting the most focused image from the image of each part of the captured wire. That is, this wire automatic inspection is performed in the following procedure.

(1) The wire is aligned with the camera by moving the XY stage.

(2) The imaging is repeated while gradually increasing the distance between the camera and the wire by changing the height of the camera, and so on, until the vertex of the wire is detected.

(3) Conversely, imaging is repeated while the distance between the camera and the wire is gradually reduced.

(4) The most in-focus portion of each part of the wire is selected from the image acquired in (3) to obtain a three-dimensional shape of the wire.

(5) The above steps (1) to (4) are repeated until all the wire images are acquired.

In Patent Document 2, the position information of the wire in which the camera is focused at two different heights is acquired, and the vertex of the wire is estimated based on these information to correspond to the next camera height change. Thus, it is shown that the detection of the vertex of the wire is accelerated.
Japanese Patent No. 3321395 JP-A-6-307824

  By the way, the conventional pattern matching method has a feature that it is possible to inspect a plurality of wires in a short time. There is a problem that it cannot be used when the distance between wires becomes a problem, such as a short circuit.

  More specifically, it is necessary to confirm how much the degree of coincidence of the short-circuited ones is obtained, and there is a concern that misjudgment frequently occurs particularly in the initial stage. Also, since the pattern matching itself does not have a function for measuring the distance between the wires, if the distance between the wires is less than the reference value, it will conduct even though it is not actually short-circuited. This is not suitable for inspections that require measurement of the distance between wires, which is a pseudo short circuit.

  Further, the automatic wire inspection method disclosed in Patent Document 1 has a problem in that it takes too much time to inspect even if detailed data can be obtained because of the three-dimensional length measurement.

  More specifically, since an image obtained by combining wires in the most in-focus state of the camera is acquired, even if a detailed three-dimensional shape of the wire can be obtained, a camera is required to increase the accuracy of the three-dimensional shape. The distance between the wires must be changed finely, and the inspection time becomes long because the wire image is taken many times in order to acquire a wire image of one field of view. In addition, in order to inspect a wire short-circuit, it is necessary to select two points that are the shortest distance between adjacent wires from among a large number of wire position coordinates, which is also a factor that hinders shortening of the inspection time. Become.

  Further, in Patent Document 2, even if the detection of the apex of the wire becomes faster, since the fundamental solution to the problem of repeating imaging for one field of view has not yet been reached, further improvement in inspection efficiency is achieved. is required.

  An object of the present invention is to provide a printed wiring board inspection method and apparatus for automatically and simply determining a wire short circuit including a pseudo short circuit.

In order to solve the above problems, a printed wiring board inspection method of the present invention is a printed wiring board inspection method for inspecting the presence or absence of a short circuit of a circuit component in a circuit pattern of the printed wiring board.
A process of fixing a workpiece to be inspected to a workpiece mounting table;
Determining an optimum position at which the image focus of the circuit configuration unit is in focus by continuously changing the position of an imaging unit that images the circuit configuration unit of the workpiece;
Illuminating the workpiece and imaging a plurality of circuit components at the same time with the imaging means; and
Performing a binarization process for displaying only one circuit component of a captured image in one of the two colors;
A step of performing expansion processing for expanding the circuit components until the circuit components are short-circuited at a distance between circuit components equal to or less than a reference value with respect to the binarized image that has been subjected to the binarization processing;
The step of acquiring the color area of the circuit component that has undergone the expansion process and determining whether or not the color area is within a reference value that passes the inspection is performed.

  Further, the printed wiring board inspection method of the present invention is the above-described printed wiring board inspection method, wherein the circuit component connects the electronic component mounted on the printed wiring board and the printed wiring board with a wire. The wire portion is preferable.

  Further, the printed wiring board inspection method of the present invention is the above-described printed wiring board inspection method, wherein the circuit component connects the electronic component mounted on the printed wiring board and the printed wiring board with a wire. The bonding part is preferably.

  Moreover, in the printed wiring board inspection method of the present invention, in the printed wiring board inspection method, it is preferable that the circuit component is a circuit constituting a circuit pattern.

  In the printed wiring board inspection method of the present invention, in the printed wiring board inspection method, when the imaging means performs inspection of different visual fields adjacent to each other in the workpiece, a portion serving as an edge of the adjacent visual field is obtained. It is preferable to inspect in an overlapping manner.

  The printed wiring board inspection method of the present invention is necessary for the binarized image obtained by performing the binarization process before and after the step of performing the expansion process in the printed wiring board inspection method. Accordingly, it is preferable to perform a step of performing a shrinkage treatment.

  Further, the printed wiring board inspection method of the present invention is the above-described printed wiring board inspection method, wherein the image picked up by the imaging means, the binarized image obtained by performing the binarization process, and the contraction obtained by performing the contraction process. It is preferable to store at least one of the processed image or the expanded image subjected to the expansion process.

The printed wiring board inspection apparatus of the present invention is a printed wiring board inspection apparatus that inspects for the presence or absence of a short circuit in a circuit component in the circuit pattern of the printed wiring board.
A workpiece mounting table for fixing the workpiece to be inspected;
Imaging means for collectively imaging a plurality of circuit components of the workpiece on the workpiece mounting table;
A binarization processing device that performs binarization processing for displaying only the circuit configuration unit in one of two colors for an image captured by the imaging unit;
An expansion processing device that performs an expansion process on the binarized image that has been subjected to the binarization process to expand the circuit components until the circuit components are short-circuited at a distance between circuit components that is equal to or less than a reference value; ,
An arithmetic device that calculates the color area of the circuit component that has undergone the expansion process, and a comparative determination that determines whether or not the color area of the circuit component calculated by the arithmetic device is within a reference value that passes the inspection. And a control device provided with the device.

  In the printed wiring board inspection apparatus according to the present invention, in the printed wiring board inspection apparatus, the circuit component section performs wire bonding for connecting the electronic component mounted on the printed wiring board and the printed wiring board with a wire. The wire portion is preferable.

  In the printed wiring board inspection apparatus according to the present invention, in the printed wiring board inspection apparatus, the circuit component section performs wire bonding for connecting the electronic component mounted on the printed wiring board and the printed wiring board with a wire. The bonding part is preferably.

  In the printed wiring board inspection apparatus according to the present invention, in the printed wiring board inspection apparatus, it is preferable that the circuit component is a circuit constituting a circuit pattern.

  In the printed wiring board inspection device according to the present invention, in the printed wiring board inspection device, the control device may instruct the imaging to overlap and image portions adjacent to the ends of different fields of view in the workpiece. It is preferable to provide a command unit to be provided to the means.

  In the printed wiring board inspection apparatus according to the present invention, in the printed wiring board inspection apparatus, before and after the expansion processing apparatus, the binarization processing image is subjected to binarization processing. On the other hand, it is preferable to provide a shrinkage treatment apparatus that performs a shrinkage treatment as necessary.

  In the printed wiring board inspection apparatus according to the present invention, in the printed wiring board inspection apparatus, the control device picks up an image picked up by the image pickup means, a binarized image obtained by performing the binarization processing, and the contraction. It is preferable to include a storage device that stores at least one of the contracted image subjected to the processing or the expanded image subjected to the expansion processing.

  As can be understood from the means for solving the above problems, according to the printed wiring board inspection method and apparatus therefor of the present invention, binarization processing and expansion processing are performed on an image captured by the imaging means. By the two image processes, it is possible to automatically and accurately and quickly perform a judgment inspection of a circuit component short circuit including a pseudo short circuit. As a result, the inspection of the circuit components that has been performed by visual inspection of the worker can be automatically performed based on the color area after the image processing. The inspection accuracy is improved without being affected by variations in defect detection ability due to the physical condition / fatigue of the operator.

  Furthermore, since a plurality of circuit components are simultaneously inspected with one visual field, the inspection time can be greatly shortened. Further, in the future, even when the wiring density of the printed wiring board increases to limit human visual inspection, it is possible to perform the same inspection by increasing the number of pixels of the imaging means.

  Embodiments of the present invention will be described below with reference to the drawings.

  Referring to FIG. 1, a printed wiring board inspection apparatus 1 according to this embodiment is an apparatus for inspecting the presence or absence of a short circuit in a circuit component in a circuit pattern of a printed wiring board. For example, it is an apparatus for automatically inspecting the wire bonding with respect to the work 3 to be inspected, which has been subjected to wire bonding, which is an example of the circuit configuration unit.

  Specifically, as shown in FIG. 2, the workpiece 3 to be inspected includes, for example, a semiconductor chip 5 as an electronic component (mounted component) mounted on a printed wiring board 7 (mounted substrate). . In the wire bonding, the semiconductor chip 5 and the printed wiring board 7 directly connect the pads 9 on the semiconductor chip 5 and the substrate side circuit 11 on the printed wiring board 7 with a large number of wires 13. 5 and the printed wiring board 7 are electrically connected. In addition, as said wire 13, the material of gold | metal | money and aluminum is used suitably.

  Referring to FIG. 1 again, the printed wiring board inspection device 1 is a device for determining a short circuit between adjacent wires 13 and fixes the workpiece 3 to be inspected as shown in FIG. Then, for example, an XY stage 17 as a workpiece mounting table that moves to the inspection area 15 and an imaging unit that collectively images a plurality of wires 13 of the workpiece 3 of the XY stage 17 in the inspection area 15. For example, a CCD camera 19 is provided. The XY stage 17 has a function of correcting the XY coordinates and angle of the workpiece 3.

  The CCD camera 19 is used to focus the image by moving the lens 21 up and down when imaging the workpiece 3 of the XY stage 17, and is connected to the control device 23. The CCD camera 19 is provided with an illumination device 27 for irradiating the workpiece 3 of the XY stage 17 with illumination 25 such as an LED.

  The XY stage 17 is configured to be moved in and out of the inspection area 15 by the stage moving device 29, and the stage moving device 29 is connected to the control device 23. The CCD camera 19 is connected to an image processing device 31 for processing an image captured by the CCD camera 19.

As the image processing device 31, the captured image is displayed in, for example, two colors of black and white, and only the portion of the wire 13 is displayed in, for example, one of black and white or black. In this embodiment, white is displayed. And the distance between the wires 13 below the reference for the binarization processing device 33 that performs the binarization processing and the binarization processing image that has been binarized by the binarization processing device 33. Then, an expansion processing device 35 that performs an expansion process for expanding the white color of the wire 13 until the wires 13 are short-circuited is provided. The expansion processing device 35 is connected to the control device 23.

  Referring to FIG. 4, the control device 23 includes a CPU 37 as a central processing unit. The CPU 37 includes an input device 39 such as a keyboard and a touch panel for inputting various data and programs, a CRT, Stores a display device 41 such as a liquid crystal, a program input from the input device 39, various detection data, a binarized image obtained by the binarization process, an expansion-processed image obtained by the dilation process, and the like. And a memory 43 (storage device).

  Further, the CPU 37 checks the color area of the portion of the wire 13 subjected to the expansion processing by the expansion processing device 35 and the color area of the portion of the wire 13 calculated by the calculation device 45. A comparison / determination device 47 is connected to determine whether the reference value is acceptable.

  Further, as shown in FIG. 5, the CPU 37 is connected to a command unit 49 that gives a command to the CCD camera 19 for imaging the overlapping parts of the different fields of view adjacent to each other in the work 3. ing.

  If there is a foreign object on the printed wiring board 7, if the captured image is binarized, the foreign object is judged to be white, so that an erroneous determination due to the foreign object is prevented. In addition, a contraction processing device 51 for performing contraction processing on the binarized image that has been binarized can be provided. The contraction processing device 51 is connected to the control device 23. In addition, it will be described in detail in a printed wiring board inspection method to be described later that the foreign matter causes an erroneous determination.

  Next, a printed wiring board inspection method according to an embodiment of the present invention will be described using the printed wiring board inspection apparatus 1 described above.

  The workpiece 3 to be inspected is wire-bonded as shown in FIG. 2, and is as described above.

  As shown in FIG. 3, the workpiece 3 to be inspected is fixed on, for example, an XY stage 17 as a workpiece mounting table. The work 3 is fixed as long as the work 3 is not deformed, such as bent, wrinkled, torn, or warped during inspection, or unless the work 3 is displaced due to the movement of the XY stage 17. Adsorption or fixing jigs can be used, or other fixing methods can be arbitrarily used.

  Thereafter, as shown by a two-dot chain line in FIG. 1, a workpiece transfer process is performed in which the XY stage 17 to which the workpiece 3 is fixed is moved to the inspection area 15 by the stage moving device 29.

  In the inspection area 15, first, the work 3 is irradiated with the illumination 25 such as the LED of the illumination device 27, and the height of the CCD camera 19 is continuously changed above the work 3, whereby the CCD camera 19 with respect to the wire 13 is changed. An imaging focus adjustment step for determining an optimum height for focusing is performed. That is, the height of the CCD camera 19 is automatically adjusted to focus.

  After this, since the surface of the work 3 is provided with at least two predetermined patterns (recognition marks) as reference points for image recognition, by recognizing the above two patterns by the CCD camera 19, A workpiece position correcting step for correcting the XY coordinates and angle of the workpiece 3 is performed by the XY stage 17.

  Next, an imaging process is performed in which a plurality of wires 13 are collectively imaged by the CCD camera 19 focused in the imaging focus adjustment process. That is, the XY stage 17 is moved so that a plurality of wires 13 are viewed within one field of view, and then the plurality of wires 13 are collectively imaged by the CCD camera 19.

  The captured image is subjected to two-step image processing by the image processing device 31. That is, first, in the binarization processing device 33, for example, in this embodiment, the captured image of the wire 13 is displayed in two colors of black and white, and only the portion of the wire 13 is, for example, black and white. A binarization processing step is performed in which binarization processing is performed by setting a binarization threshold so that one of the colors is displayed in white or black. In this embodiment, the wire 13 is white.

Next, in the expansion processing device 35, with respect to the binarized image 53 that has been subjected to the above binarization processing, a portion of the wire 13 until the wires 13 are short-circuited at a distance between the wires 13 that is equal to or less than a reference value. An expansion process step is performed for performing an expansion process for expanding the white color.

  Next, the control device 23 calculates the color area of the portion of the wire 13 of the expansion processing image 55 that has been subjected to the expansion processing by the expansion processing device 35 by the arithmetic device 45, and the comparison determination device 47 calculates the color of the calculated wire 13. An inspection determination step is performed to determine whether the color area of the portion is within a predetermined range corresponding to one wire 13, that is, whether it is within a reference value that is a non-defective product that passes the inspection.

  For example, FIG. 5A shows an image immediately after the binarization processing in which only the portion of the wire 13 is displayed in white by the black and white binarization processing on the image of the inspection range 57 of one visual field. In this embodiment, the white of the portion of each wire 13 is expanded as shown in FIG. 5B by performing expansion processing on the binarized image 53. In the case of FIG. 5B, since the white color of the expanded wire 13 portion does not overlap between the wires 13, the color area of the expanded wire 13 portion is within the reference value, so it is determined as “pass”. Is done.

  Conversely, when the white portion of the expanded wire 13 overlaps between adjacent wires 13, the color area of the overlapped portion is approximately doubled, so that a pseudo short circuit or a wire short circuit has occurred. Judgment is made and it is determined as “fail”. For example, in the state immediately after the binarization processing as shown in FIG. 6A, the wire 13B and the wire 13C are not short-circuited, but the interval A between the wires 13B and 13C is narrow. When the distance A is equal to or less than the reference value for pseudo short-circuiting, even when the wires 13B and 13C are not directly short-circuited, the portion of the overlapping wires 13 as shown in FIG. Since the area of the white of this is about twice that of a normal area and appears to be short-circuited, a pseudo short-circuit or a wire short-circuit can be determined.

  In this embodiment, when the distance between the wires 13 in which the pseudo short circuit occurs is a distance of the width dimension of one wire 13, the pseudo short circuit is equal to or less than the distance of the width dimension of one wire 13. The state where they are close to each other. Therefore, when the image processing is performed so that the width of the wire 13 of the binarized image 53 is doubled in the expansion processing, the wire expanded in the expansion processing image 55 in the case of the pseudo short circuit or the actual wire short circuit. Since the 13 white portions overlap, the area becomes larger than the reference value, so that it is easy to determine the short circuit state.

  As described above, after the inspection of the wire 13 of one field of view, the workpiece 3 is moved to another field of view, and the wire 13 of another field of view is inspected by the same means as described above.

  At this time, according to an instruction given by the command unit 49, for example, as shown in FIG. 7, a portion which is the right end of the inspection range 57A of one visual field and an inspection range 57B of another visual field to be inspected next. The leftmost part of each is inspected in an overlapping manner. The reason for this is that, as shown in FIG. 8, when the adjacent ends of the adjacent inspection ranges 57A and 57B are located within the interval between the wires 13, the interval between the adjacent wires 13 at that location is as follows. This is because an inspection omission occurs to prevent this omission.

  As described above, the above inspection process is automatically repeated so that all the wires 13 of the workpiece 3 are inspected without omission.

  If there is a foreign object 59 on the printed wiring board 7, when the captured image is binarized, as shown in FIG. When the binarized image 53 is expanded, the foreign material 59 is also expanded and the white area of the foreign material 59 is increased as shown in FIG. 9B. The white portion of the wire 13 may be erroneously determined as being short-circuited, and may be determined as “failed”.

  Therefore, in order to prevent the erroneous determination by the foreign matter 59, the binarized image 53 that has been binarized as shown in FIG. 10A is temporarily displayed in FIG. 10B. As shown in FIG. 10, the contraction processing is performed by the above-described contraction processing device 51 to remove the white portion of the foreign matter 59 from the image, and the contraction processing image 61 is subjected to the expansion processing. As shown in (), only the portion of the wire 13 is expanded in a state of being displayed in white. Therefore, it is possible to prevent erroneous determination by performing pass / fail determination on the expansion processed image 55 by the comparison determination device 47 as described above.

  As described above, by applying the contraction process and the expansion process to the binarized image 53 in combination, the influence of the foreign matter 59 can be eliminated.

  In addition, it is desirable that a recording process is performed in which the above-described comparison / determination device 47 stores an image that has been determined to pass or fail in the memory 43. That is, at least the wire image acquired by the CCD camera 19, the binarized image 53 after the binarization process used for the determination, the contraction processed image 61 subjected to the contraction process, or the expansion processed image 55 subjected to the expansion process. By storing and storing one or more in the memory 43, it is possible to investigate defects.

  In the above-described embodiment, the inspection of the short circuit between the adjacent wires 13 is described as the circuit component in the circuit pattern of the printed wiring board 7. However, the inspection of the short circuit of the adjacent bonding unit is also the inspection of the wire. Similarly, it is fixed on the XY stage, the focus is adjusted by continuously changing the height of the CCD camera, and the bonding part is illuminated to illuminate a plurality of bondings at once. Can be implemented by performing binarization processing for displaying one of the two colors, performing expansion and contraction processing as necessary, and determining whether the color area of the bonding portion is within the reference value. is there. Also, not only for wire bonding, but also for general circuits of printed wiring boards, it is similarly fixed on the XY stage, and the focus is adjusted by continuously changing the height of the CCD camera, and the circuit section is illuminated. Irradiate and image multiple circuits at once, perform binarization processing to display only the circuit part in one of two colors, perform expansion and contraction processing as necessary, and reduce the color area of the bonding part It can be implemented by determining whether or not it is within the reference value.

  As described above, according to the printed wiring board inspection method and the apparatus 1 according to the embodiment of the present invention, the image picked up by the image pickup means is subjected to the two image processings of the binarization processing and the expansion processing. It is possible to automatically and accurately perform a wire short circuit determination test including a pseudo short circuit at high speed.

  As a result, the inspection of wire bonding, which has been performed by visual inspection of the worker so far, can be automatically performed based on the color area of the wire 13 after image processing. Inspection accuracy is improved without being affected by variations and variations in defect detection ability due to the physical condition and fatigue of the operator.

  Furthermore, since a plurality of wires 13 are inspected simultaneously in one field of view, the inspection time can be shortened. Further, in the future, even when the wiring density of the printed wiring board 7 increases and the human visual inspection becomes limited, the inspection can be similarly performed by increasing the number of pixels of the CCD camera 19.

It is a schematic explanatory drawing which shows the inspection apparatus of the printed wiring board of embodiment of this invention. It is a schematic explanatory drawing of the workpiece | work used by embodiment of this invention. It is a schematic explanatory drawing of the XY stage which mounted the object workpiece | work. It is a block block diagram of a control apparatus. (A) is a top view which shows the image after the binarization process in the workpiece | work of an acceptable product, (B) is a top view which shows the image after an expansion process with respect to (A). (A) is a top view which shows the image after the binarization process in the workpiece | work of a rejection product, (B) is a top view which shows the image after an expansion process with respect to (A). It is a top view which shows the state which overlapped the end of the adjacent test | inspection range when imaging. It is a top view which shows the state which the inspection omission produced in order not to overlap the end of the adjacent test | inspection range when imaging. (A) is a top view which shows the image after the binarization process in the workpiece | work when the foreign material 59 exists, (B) is a top view which shows the image after an expansion process with respect to (A). (A) is a top view which shows the image after the binarization process in the workpiece | work with the foreign material 59, (B) is a top view which shows the image after a shrinkage | contraction process with respect to (A), (C) FIG. 4B is a plan view showing an image after expansion processing with respect to (B).

Explanation of symbols

1 Printed Wiring Board Inspection Device 3 Work 5 Semiconductor Chip (Electronic Component)
7 Printed wiring board 13 Wire 15 Inspection area 17 XY stage (work placement table)
19 CCD camera (imaging means)
23 control device 27 illumination device 29 stage moving device 31 image processing device 33 binarization processing device 35 expansion processing device 43 memory (storage device)
45 arithmetic unit 47 comparison judgment device 49 command unit 51 contraction processing device 53 binarization processing image 55 expansion processing image 57 inspection range 59 foreign matter 61 contraction processing image

Claims (14)

In the method for inspecting a printed wiring board for inspecting the presence or absence of a short circuit in a circuit component in the circuit pattern of the printed wiring board,
A process of fixing a workpiece to be inspected to a workpiece mounting table;
Determining an optimum position at which the image focus of the circuit configuration unit is in focus by continuously changing the position of an imaging unit that images the circuit configuration unit of the workpiece;
Illuminating the workpiece and imaging a plurality of circuit components at the same time with the imaging means; and
Performing a binarization process for displaying only one circuit component of a captured image in one of the two colors;
A step of performing expansion processing for expanding the circuit components until the circuit components are short-circuited at a distance between circuit components equal to or less than a reference value with respect to the binarized image that has been subjected to the binarization processing;
A method for inspecting a printed wiring board, comprising: obtaining a color area of a circuit component that has undergone the expansion process and determining whether the color area is within a reference value that passes the inspection. .   The printed circuit board inspection method according to claim 1, wherein the circuit component is a wire bonding wire section that connects the electronic component mounted on the printed circuit board and the printed circuit board with a wire.   The printed circuit board inspection method according to claim 1, wherein the circuit component is a wire bonding bonding unit that connects the electronic component mounted on the printed circuit board and the printed circuit board with a wire.   The printed circuit board inspection method according to claim 1, wherein the circuit component is a circuit constituting a circuit pattern.   5. The print according to claim 1, wherein when the imaging means inspects different fields of view adjacent to each other in the workpiece, a part serving as an end of the adjacent field of view is overlapped. Inspection method for wiring boards.   The step of performing a contraction process as necessary on the binarized image that has been subjected to the binarization process is performed before and after the step of performing the expansion process. 4. A method for inspecting a printed wiring board according to 4 or 5.   Storing at least one of an image captured by the imaging unit, a binarized image that has undergone the binarization process, a contracted image that has undergone the contraction process, or an expansion-processed image that has undergone the expansion process. The printed wiring board inspection method according to claim 1, 2, 3, 4, 5 or 6. In a printed wiring board inspection device that inspects the presence or absence of a short circuit in a circuit component in the circuit pattern of the printed wiring board,
A workpiece mounting table for fixing the workpiece to be inspected;
Imaging means for collectively imaging a plurality of circuit components of the workpiece on the workpiece mounting table;
A binarization processing device that performs binarization processing for displaying only the circuit configuration unit in one of two colors for an image captured by the imaging unit;
An expansion processing device that performs an expansion process for expanding the circuit components until the circuit components are short-circuited at a distance between circuit components that is equal to or less than a reference value with respect to the binarized image that has been subjected to the binarization process; ,
An arithmetic device that calculates the color area of the circuit component that has undergone the expansion process, and a comparative determination that determines whether or not the color area of the circuit component calculated by the arithmetic device is within a reference value that passes the inspection. A printed wiring board inspection device comprising: a control device including the device.   9. The printed wiring board inspection apparatus according to claim 8, wherein the circuit component part is a wire bonding wire part that connects the electronic component mounted on the printed wiring board and the printed wiring board with a wire.   9. The printed wiring board inspection apparatus according to claim 8, wherein the circuit configuration unit is a wire bonding bonding unit that connects the electronic component mounted on the printed wiring board and the printed wiring board with a wire.   The printed circuit board inspection apparatus according to claim 8, wherein the circuit configuration unit is a circuit that forms a circuit pattern.   The said control apparatus is provided with the instruction | command part which gives the instruction | command to the said imaging means to overlap and image | photograph the part which becomes the edge of the different visual field adjacent in the said workpiece | work. The printed wiring board inspection apparatus according to 11.   Before and after the expansion processing device, a contraction processing device that performs a contraction processing on the binarized image that has been binarized by the binarization processing device as necessary is provided. The printed wiring board inspection device according to claim 8, 9, 10, 11, or 12.   At least one of the image picked up by the image pickup means, the binarized image processed by the binarization process, the contracted image processed by the contraction process, or the expansion processed image subjected to the expansion process by the control device. 14. A printed wiring board inspection apparatus according to claim 8, further comprising a storage device for storing the above.

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