JP2000183493A - Printed board inspection supporting apparatus and method for inspecting printed board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily find out a circuit pattern having a fault on a board to be inspected by a visual inspection, and to alleviate a labor of an inspector by generating an identifying image superposed on a circuit pattern on the board to be inspected projectively based on pattern information as an image to be projected by an identifying image projecting means. SOLUTION: A projector 1 receives image data output from a controller. An image having a luminance value responsive to image data on a board A to be inspected is formed on a liquid crystal panel, and the image is projected on the board A. A board-to-be-inspected support base 2 is provided on an upper surface of a body 4. The board A is supported parallel to a projecting surface of the projector 1 so that the board A is disposed at a focal point position of the projector 1. A positioning piece 2a for positioning the board A is provided on the base 2. An FD driver 3 inputs CAD data of the board A and information of an identifier or the like of a circuit pattern to be considered to have a fault to a controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for finding a defect in a circuit pattern on a printed circuit board, and more particularly, to superimposing an identification figure on a circuit pattern which seems to have a defect on a substrate to be inspected. The present invention relates to an apparatus and a method for assisting in visually finding a defect.

[0002]

2. Description of the Related Art In a printed circuit board inspection, generally, after conducting a continuity test or an insulation test on a circuit pattern of a printed circuit board, a human finally visually observes a circuit pattern which is determined to be defective. Then, the defect is found, and a decision is made as to whether to discard or repair and use. As a conventional method for finding and confirming a defect of a circuit pattern on a printed circuit board by a human eye, there is a method using an image synthesizing technique.
In this method, first, a substrate to be inspected is photographed by a CCD camera or the like and is taken into a computer. On the other hand, an identifier of a circuit pattern that has been subjected to a continuity test or the like and found to have a defect such as disconnection or short circuit is input to the computer. The computer has CAD data of the board to be inspected, and detects a circuit pattern having the input identifier from an image of the printed board taken by the CCD camera based on the CAD data. Are superimposed and displayed on the monitor.
The inspector visually compares the monitor screen with the actual board to find a defective portion, and performs confirmation and judgment.

There is another method using a half mirror. For this, an apparatus in which a half mirror 63 is installed between a liquid crystal display 61 and a table 62 on which the substrate A to be inspected is placed as shown in FIG. 7 is used. This device is
It is set so that the inspected board A and the image displayed on the liquid crystal display 61 overlap when viewed from a predetermined position by the inspector. In the inspection method, an identifier of a circuit pattern determined to be defective by a continuity test or the like is input to a computer having CAD data of a substrate to be inspected, and an identification graphic such as a “dotted line” is placed at a position of the circuit pattern having the identifier. It is formed and displayed on a liquid crystal display. When displayed on the liquid crystal display, the identification graphic is displayed in a size and a position such that it appears to the inspector via the half-mirror just to overlap the actual circuit pattern on the substrate. The inspector looks at the image on the half mirror where the identification figure and the actual substrate to be inspected overlap with each other, finds a defective portion, and makes a judgment or the like.

[0004]

However, in the case of using the former method, it is necessary to compare the monitor screen with the actual printed circuit board. It is not easy to find a circuit pattern, and the work time and labor of the inspector are wasted. On the other hand, according to the latter method, the defective circuit pattern on the substrate can be easily found because the identification pattern is directly superimposed. However, in this method, the image on the liquid crystal display and the substrate to be inspected appear to overlap each other via the half mirror only when the inspector's line of sight is at a specific position. The defective circuit pattern will not overlap. For this reason, the examiner must keep his gaze position fixed, and he is nervous and tired. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is possible to easily find a defective circuit pattern from a substrate to be inspected by visual inspection of a printed circuit board, and furthermore, to reduce the labor of the inspector. It is an object to provide an apparatus and a method for mitigating this.

[0005]

In order to solve the above-mentioned problems, a printed circuit board inspection support apparatus according to the present invention comprises a substrate supporting means for supporting a substrate to be inspected, and an image projected onto the supported substrate to be inspected. Image projection means, and further,
Pattern information receiving means for receiving pattern information relating to the shape and position of one or more circuit patterns of the substrate to be inspected;
Identification image generating means for generating an identification graphic image overlapping the circuit pattern on the inspection target substrate as an image projected by the image projection means at the time of projection based on the received pattern information. Note that the pattern information includes various information such as information obtained by combining information relating to a circuit pattern of a circuit such as CAD data with an identifier indicating a specific circuit pattern, and image data of a board including only a specific circuit pattern. The expression "overlapping the circuit pattern on the substrate to be inspected at the time of projection" also includes a case where it is possible to overlap by adjusting the focus or the projection angle of the image projection means.

With this configuration, the pattern information receiving means receives pattern information relating to the shape and position of one or more circuit patterns which are considered to have a defect on the substrate to be inspected, which is input from the outside, and generates an identification image. The means generates an identification graphic image overlapping with the circuit pattern on the inspection target board at the time of projection based on the received pattern information. Then, the image projecting means projects the generated identification figure image onto the substrate to be inspected supported by the substrate supporting means. Since the projected identification graphic image is directly projected on a circuit pattern that is considered to have a defect on the substrate to be inspected, the inspector can superimpose the identification graphic on the circuit pattern without shifting from any viewpoint position. In addition, since the state of the defect can be observed by visually observing the circuit pattern on the substrate directly based on the projected identification figure, the inspector can perform the operation easily and quickly.

Further, if the image projection means is a projector, the identification figure is projected more clearly on the printed circuit board, so that the work of the inspector becomes easier. In addition, since the electric signal indicating the image can be directly converted into a projected image, it is not necessary to create an original image on a transparent sheet such as a slide, so that it is efficient. Further, the image projecting means is constituted by two or more projectors, and each of the projectors projects each of the divided areas of the substrate on the substrate supporting means, and the identification image generating means is provided for each area projected by each projector. An identification graphic image may be generated. By doing so, a wider area can be shared by a plurality of projectors and an image can be projected, which is suitable when testing a large printed circuit board.

In addition, the image projection means can be moved in parallel with respect to a main plane of a substrate to be inspected supported by the substrate support means, and the identification image generation means is changed in accordance with the amount of parallel movement. The identification figure image can be generated according to the projection range to be performed. In addition,
The “principal plane” of the substrate to be inspected refers to the surface of the substrate to be inspected on which wiring is provided. With this configuration, it is possible to project an image on a wider surface by moving the image projection unit and the substrate support unit in parallel relative to each other, which is also suitable for inspecting a larger printed circuit board. .

In order to solve the above problems, a printed board inspection support method according to the present invention is a method for supporting printed board inspection by projecting an identification graphic image for inspection on a board to be inspected by a projection means. An inspection substrate supporting step of supporting the inspection substrate at a predetermined position, and identification overlapping with the circuit pattern on the inspection substrate based on pattern information relating to a shape and a position of one or more circuit patterns of the inspection substrate. An identification image generating step of generating a graphic image;
An identification image projecting step of projecting the identification graphic image onto the substrate to be inspected by the projecting means so that the generated identification graphic image and the circuit pattern on the substrate to be inspected overlap with each other. With such a configuration, when information of a circuit pattern considered to be defective is given as pattern information, an identification image is generated in the identification image generation step so as to overlap a circuit pattern considered to be defective based on the pattern information. In the identification image projecting step, the identification image is projected on the substrate to be inspected. Therefore, since the identification graphic is directly projected on the circuit pattern, when the inspector visually inspects the circuit pattern on which the identification graphic is projected, the inspector does not need to worry about the movement of the line of sight, and also performs the inspection with the monitor or the like. The inspection can be performed easily and quickly without performing the comparison.

Further, in the recording medium according to the present invention,
The computer records a program for generating, by a computer, an identification graphic image for inspection projected on the supported substrate to be inspected by the image projection means, the program relating to the shape and position of one or more circuit patterns on the substrate to be inspected. A program for causing the computer to execute a pattern information receiving step and an identification image generating step of generating an identification graphic image overlapping the circuit pattern of the inspection target substrate as an image projected by the projection unit at the time of projection based on the received pattern information. Is recorded. With such a configuration,
When the circuit information of the circuit pattern considered to be defective is given, the circuit information is received by the pattern information receiving step,
Based on this, in the identification image generation step, an identification figure image just overlapping the circuit pattern is generated. This image is projected onto the substrate to be inspected by the image projecting means so that the identification image overlaps the corresponding circuit pattern, so that the inspector can easily find and confirm the defect of the substrate.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of a printed circuit board inspection support device according to the present embodiment. The printed board inspection support apparatus includes a projector 1 serving as an image projection unit, a board support 2 that supports the board A to be inspected and keeps a distance between the projector 1 and the board A to be inspected, an FD drive 3 for reading data, And a main body 4 having a built-in control unit. Here, the projector 1 receives an image data output from a control unit to be described later, and forms an image having a luminance value corresponding to the image data on a liquid crystal panel on a substrate A to be inspected supported on the substrate support 2. ,
This is projected by the backlight, so that the inspection target substrate A
Project the image on top. Note that here, the projector 1
Although a device that projects an image in a single color is used, a device that can project a color image may be used.

The substrate support 2 is provided on the upper surface of the main body 4 to support the substrate A to be inspected in parallel with the projection plane of the projector 1 and to position the substrate A to be inspected just at the focal length of the projector 1. I do. Substrate support 2
Is provided with a positioning piece 2a for positioning the substrate A to be inspected. The positioning piece 2a is made of two rods that intersect at right angles, and is fixed to the position where the reference edges in the vertical and horizontal directions of the substrate A to be inspected should be located. Then, the inspection target board A is assumed to be located at a position where both reference edges are in contact with the inner edge of the positioning piece 2a.
A projection image of the projector 1 is generated. That is, if both reference edges of the substrate A to be inspected are in contact with the positioning pieces 2a, the circuit pattern on the substrate A to be inspected and the identification figure projected from the projector overlap as described later.

The FD drive 3 accesses a floppy disk on which predetermined data is recorded in accordance with an instruction from a control unit to be described later, reads out the data, and sends the data to the control unit. It is used to input information such as an identifier of a circuit pattern that seems to be present to the control unit. Here, F is used as an input device.
Although the D drive is used, this may be another recording device such as a CD drive or an input device such as a keyboard. Furthermore, it is also possible to connect online with another computer or the like and directly input data from the computer or the like.

Next, a control section built in the main body 4 will be described. The control unit includes a CPU, a RAM, a ROM, and the like. FIG. 2 is a functional block diagram showing the configuration of the control unit. As shown in the figure, the control unit 100 functionally includes a data reading unit 101, a data storage unit 102, a pattern information receiving unit 103, and an identification image generating unit 104. The data reading unit 101 issues an instruction to the FD drive 3 and reads data relating to the substrate A to be inspected. Specifically, the data read by the data reading unit includes CAD data relating to the positions and shapes of all the circuit patterns of the substrate A to be inspected, and circuit pattern designation data for specifying the circuit pattern of the substrate A to be inspected.
In CAD data, identifiers are given to all circuit patterns, and in circuit pattern designation data, circuit identifiers are identified by the identifiers. Usually, a plurality of printed circuit boards of the same form with the same circuit pattern are inspected consecutively.
First, the CAD data common to the plurality of substrates to be inspected is read in advance, and circuit pattern instruction data for a circuit pattern requiring visual inspection is input for each individual substrate to be inspected.

The data storage unit 102 stores the data read unit 10
1 stores the read data. As described above, first, since the CAD data is sent from the data reading unit 101, the data storage unit 102 stores this first, and then the circuit pattern sent for each of the inspected substrates. The instruction data is stored. Here, the circuit pattern instruction data may not be stored, and may be used only as key information for extracting the position and shape of a specific circuit pattern from CAD data. Here, data is temporarily stored in the data storage unit, but this is not essential, and data relating to the position and shape of a specific circuit pattern relating to the substrate to be inspected is directly input from an external input device. You may do so.

The pattern information receiving unit 103 receives pattern information on the shape and position of a specific circuit pattern on the substrate A to be inspected. That is, using the CAD data stored in the data storage unit, data relating to the shape and position of the circuit pattern specified by the circuit pattern specification data is extracted and received as pattern information. When the projector 1 projects an image based on the received pattern information, the identification image generation unit 104 projects the identification graphic image that overlaps the circuit pattern on the inspection target board A specified by the circuit pattern designation data. Is generated as an image to be processed. More specifically, first, the identification image generation unit 10
Reference numeral 4 stores in advance a reference line segment position of a generated image projected on the inner edge of the positioning piece 2a provided on the substrate support 2 when the projector 1 projects. Then, the entire substrate is virtually positioned such that both reference edges of the inspection target substrate A indicated by the CAD data are in contact with the reference line segment position.
Then, based on the pattern information indicating the position and shape of the specific circuit pattern, an area occupied by the specific circuit pattern with respect to this position is determined, and a "dotted line" is generated as an image that overlaps this area as an identification figure. Here, the generated image data is automatically output to the projector 1. This identification figure is not limited to a “dotted line”, but may be a straight line, a dashed line, the same shape as a circuit pattern,
Various things such as a circle and a triangle can be used, and colors that are easily recognizable and blinking can be used.

The control section 100 can also be realized by incorporating a program that causes a general computer to perform the above-described functions or the following operations. This program can be implemented by a computer-readable floppy disk or the like. It can be recorded on a recording medium.
Further, this program can be read out via communication means such as the Internet.

Next, the operation and use of the printed board inspection support apparatus will be described. FIG. 3 is a flowchart showing the operation of the printed circuit board support device. The floppy disk on which CAD data of the board to be inspected is recorded
The data is inserted into the drive 3, and the CAD data is read by the data reading unit 101 of the control unit 100 and stored in the data storage unit 102 (s101). Here, it is assumed that a printed wiring board having circuit patterns a to e as shown in FIG. Therefore, the CAD data includes data relating to the shapes and positions of the circuit patterns a to e, identifiers of the circuit patterns a to e, and data such as the size of the substrate.

A resistance test is separately performed on the substrate to be inspected, and an identifier of a circuit pattern having a result such as a disconnection or a short circuit is extracted and recorded on a floppy disk. This data becomes circuit pattern designation data. Here, it is assumed that the circuit pattern a and the circuit pattern d are obtained as defective data in the printed wiring board of FIG. The substrate to be inspected after the resistance inspection is set on the substrate support 2 with its reference edge aligned with the positioning piece 2a. Then, the floppy disk is inserted into the FD drive 3, and the circuit pattern designation data is read by the data reading unit 101 of the control unit 100 and stored in the data storage unit 102 (s102).

Then, the pattern information, which is data relating to the shape and position of the circuit pattern which is considered to be defective, is extracted from the contents stored in the data storage unit 102 and received by the pattern information receiving unit 103 (s103). Further, an identification figure is created by the identification image generation unit 104 based on the received pattern information (s104). Now, the circuit pattern a and the circuit pattern d in the printed wiring board of FIG.
Is designated, the identification graphic image a as shown in FIG.
o and do are generated by the identification image generation unit 104. This image data is automatically sent to the projector and projected on the substrate to be inspected placed on the substrate support 2 (s1).
05). As a result, the projected image of the identification figure appears on the circuit pattern of the substrate to be inspected in an overlapping manner. FIG.
When the identification figure image shown in FIG. 4B is projected on the printed wiring board shown in FIG. 4A, it looks as shown in FIG. 4C.

In this state, the degree of the actual defect of the circuit pattern in which the identification pattern is overlapped appears visually by the inspector, and it is determined whether the circuit pattern should be repaired or discarded (s106). At this time, since the identification image is projected directly on the printed wiring board, the inspector can see the identification image and the specific circuit pattern overlapping from any viewpoint, thereby reducing inspection labor. This completes the inspection of one substrate to be inspected. Further, when there is another substrate having the same CAD data, the process returns to s102, and when there is no other substrate, the process ends (s107).

Here, the circuit pattern designation data is read and stored for each setting of the substrate. However, the circuit pattern designation data is stored in association with the identification number such as the production number of each substrate to be inspected. Alternatively, a plurality of circuit pattern designation data may be read and stored at once. In this case, when inspecting an individual substrate to be inspected, by inputting the identification number of the substrate to be inspected, corresponding circuit pattern designation data is searched and an identification graphic image is generated based on the data. If so, no error will occur.

In the above embodiment, an image is projected using one fixed projector. However, when a large substrate to be inspected is handled, the following method can be adopted. That is, as shown in FIG. 5, four projectors 1a to 1d may be used so that each projector projects a divided area of the inspection target substrate A on the substrate support 2. In other words, the maximum projection area assumed at the time of design as one that can be projected on the substrate support 2 is divided into four by the individual projector 1a.
1d serve as a projection area. At this time, the areas covered by adjacent projectors may overlap or may be in contact.

In this case, the identification image generation unit 104 of the control unit 100 creates an identification figure image for each area projected by each of the projectors 1a to 1d. In particular,
First, as described above, the positioning piece 2 is obtained from the pattern information.
An identification graphic image overlapping a specified circuit pattern is generated based on a reference line segment position assumed to be projected on the inner edge of a. Next, the generated identification figure image is divided into areas belonging to the area, which are illuminated with reference to the areas of the projectors 1a to 1d stored in advance based on the reference line segment position. Then, the divided image data is transmitted to the corresponding projectors 1a to 1d. This makes it possible to inspect a large printed circuit board according to the number of projectors. Although the number of projectors is four here, it goes without saying that the number and arrangement of projectors can be changed as needed.

As another method for handling a large substrate to be inspected, one projector 1 can be translated in parallel with respect to the main plane of the substrate to be inspected supported on the substrate support 2. It is also conceivable to increase the projectable area in this way. For the parallel movement, for example, various mechanisms such as a mechanism that enables a plane movement by orthogonally intersecting a ball screw used in an XY table and a mechanism that enables a plane movement by providing a linear motor in two orthogonal directions. Can be adopted. FIG. 6 shows an example of the apparatus. Here, the projector 1e is freely moved on a plane by a ball screw 1f. In the case shown in FIG. 6, the identification image generation unit 104
The identification graphic image is generated as a projection image in accordance with a projection range that changes according to the amount of parallel movement of the projector 1e. Note that the identification image generation unit 10
No. 4 needs information on the position of the projector 1e. Therefore, the number of rotations of the ball screw 1f from the reference position is optically detected, and if the ball screw 1f is driven by a stepping motor, the number of drive pulses is counted. The position of the projector 1e is calculated from the data obtained by the above and input to the identification image generation unit 104.

In such a case, the identification image generation unit 104 collates the identification graphic image generated based on the reference line segment position with the position of the projector 1e and the projection area of the projector 1e, and , An area to be actually projected is extracted and sent to the projector. Even in this case, it is possible to inspect a large printed wiring board according to the moving range of the projector. Here, the projector 1e
Is moved continuously even if it moves a little, but the image is continuously generated in accordance with this. For example, the projected image of the projector 1e may be generated in a scattered manner only at a specific moving point. In this case, the projection areas of the projector 1e at the respective moving points are set so that there is no gap between them. By doing so, the position of the projector can be specified by perceiving whether or not the projector has reached a specific moving point with a simple sensor such as a microswitch. When there are a plurality of specific moving points, it is preferable to calculate the position of the projector 1e using the rotary encoder or the like as described above.

In the above embodiment, a projector is used as the image projecting means. However, any projector can be used as long as it can directly project an image on a substrate to be inspected. It is possible to use a slide or the like that projects light. In this case, the image generated by the identification image generation unit 104 is printed on a transparent sheet or the like, and the image is projected on the substrate to be inspected by setting the image on a slide or the like as image projection means.

Further, in the above embodiment, the board to be inspected is positioned by applying two orthogonal edges of the board to the positioning piece 2a. This is performed with reference to one of the tooling holes of the board to be inspected. Alternatively, a reference member that passes through the reference member may be provided on the substrate support 2, or the substrate may be moved in accordance with a projected image.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a printed circuit board inspection support device according to an embodiment.

FIG. 2 is a functional block diagram illustrating a configuration of a control unit of the printed circuit board inspection support device.

FIG. 3 is a flowchart illustrating an operation of the printed circuit board inspection support device.

FIG. 4A is a diagram illustrating an example of a substrate to be inspected,
(B) is a diagram showing an example of an identification figure image for the board to be inspected in (a), and (c) is a view showing an example of a state in which the identification figure image is projected on the board to be inspected in (a). .

FIG. 5 is a perspective view showing a modification of the printed circuit board inspection support device.

FIG. 6 is a perspective view showing another modified example of the printed circuit board inspection support device.

FIG. 7 is a side view showing a conventional printed circuit board inspection support device.

[Explanation of symbols]

 1, 1a, 1b, 1c, 1d, 1e Projector 2 Substrate support 3 FD drive 4 Main unit 100 Control unit 101 Data reading unit 102 Data storage unit 103 Pattern information receiving unit 104 Identification image generation unit

Claims (6)

[Claims] 1. A substrate supporting means for supporting a substrate to be inspected, an image projecting means for projecting an image on the substrate to be inspected supported, and pattern information relating to a shape and a position of at least one circuit pattern of the substrate to be inspected. Pattern information receiving means for receiving, and identification image generating means for generating, as an image projected by the projection means, an identification graphic image overlapping the circuit pattern on the substrate to be inspected at the time of image projection based on the received pattern information. Printed circuit board inspection support device. 2. The printed circuit board inspection support device according to claim 1, wherein said image projection means is a projector. 3. The image projecting means comprises two or more projectors, each projector projecting a divided area of a substrate to be inspected supported by a substrate supporting means, wherein the identification image generating means comprises: 3. The printed circuit board inspection support apparatus according to claim 1, wherein an identification graphic image is generated for each area projected by each projector. 4. The apparatus according to claim 1, wherein the image projecting means is capable of moving relatively in parallel with respect to a main plane of the substrate to be inspected supported by the substrate supporting means. The printed board inspection support apparatus according to claim 1, wherein the identification figure image is generated in accordance with a projection range that changes according to the pattern. 5. A printed circuit board inspection support method for supporting an inspection of a printed circuit board by projecting an identification graphic image for inspection on a substrate to be inspected by a projection unit, wherein the inspection method supports the substrate to be inspected at a predetermined position. A substrate supporting step, and an identification image generating step of generating an identification graphic image overlapping the circuit pattern on the inspected substrate based on pattern information relating to a shape and a position of one or more circuit patterns of the inspected substrate. An identification image projecting step of projecting the identification graphic image on the inspection target substrate by the projection means so that the identification graphic image and the circuit pattern on the inspection target substrate overlap with each other. 6. A computer-readable recording medium storing a program for generating, by a computer, an identification graphic image for inspection projected on a supported substrate to be inspected by image projection means, the computer-readable recording medium comprising: A pattern information receiving step relating to a shape and a position of one or more circuit patterns; and generating an identification graphic image overlapping the circuit pattern on the substrate to be inspected as an image projected by the projection means at the time of projection based on the received pattern information. A recording medium recording a program for causing the computer to execute the identification image generation step.