JP2003302347A - Illumination device and final appearance inspection equipment for printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination device enabling easy, correct extraction of a region from a color image picked up by a color CCD camera by compensating a low illuminance which is a defect of fluorescent lamp illumination, and final appearance inspection equipment for printed wiring boards using the same. <P>SOLUTION: The illumination device 12 is used for extraction of an arbitrary region from the color image picked up by the CCD camera 1. The image can be picked up under fluorescent lamp illumination by using fluorescent lamps 21-24 having characteristics matched to sensitivity characteristics of the color CCD camera 1. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board for judging the quality of the final appearance of a printed wiring board by extracting an arbitrary area having predetermined color information from an image obtained by photographing with a color CCD camera. The present invention relates to a board final appearance inspection device and its illumination device.

[0002]

2. Description of the Related Art Conventionally, visual inspection is performed to inspect the final appearance of a printed wiring board after the solder resist printing process and the silk printing process. However, in this visual inspection, an inspection error such as an oversight may occur due to individual differences among the inspectors who perform the inspection, or the inspection accuracy may vary.

Therefore, a printed wiring board is mounted on a color CCD.
A final appearance inspection device for a printed wiring board, which takes an image with a camera and automatically inspects using image processing, has been put into practical use. However, when inspecting the final appearance of the printed wiring board after the solder resist printing process and silk printing process, the characteristics of the copper pattern part such as imposition pads and lands, the silk printing part, and the solder resist printing part are considered due to their characteristics. It is necessary to extract the machine and perform the inspection accuracy for each area.
Since each area of the copper pattern portion, the silk print portion, and the solder resist print portion has different color information, the area is extracted by various methods using the color information as a feature amount.

[0004]

According to the method of area extraction in the final appearance inspection apparatus for a printed wiring board, an image captured by a color CCD camera is divided into information of R value, G value and B value, and the image on the image is divided. A method of extracting R, G, and B values for each pixel within a preset threshold range, and a method of extracting hue, saturation, and brightness from R, G, and B values for each pixel on the image. Is calculated and extracted for each pixel on the image within the preset threshold value range for each of the hue, saturation, and brightness, but the R value, G value, and B value thresholds are In order to set properly, illumination is required to accurately reproduce the color information of the printed wiring board that is the inspection object. This printed wiring board final appearance inspection device illuminates the printed wiring board to be inspected, has appropriate brightness for the lighting device, blocks the influence of ambient light, has a stable light source, and replaces the lamp. Conditions such as ease of use will be required.

Conventionally, a halogen lamp, an LED, a fluorescent lamp or the like has been used as a light source in the above-mentioned lighting device. The halogen lamp has advantages such as little change over time, high illuminance, and easy replacement of the lamp, but has drawbacks such as high cost and difficulty in ensuring uniformity of illumination. Although LEDs have the advantage of having a long life, they have drawbacks such as low illuminance and difficulty in ensuring uniformity of illumination. Fluorescent lamps have the advantages of high diffusivity, high uniformity over a wide range of lighting, low cost, and easy lamp replacement, but they have the drawback of low illuminance.

Therefore, the problem to be solved by the present invention is to compensate for the low illuminance, which is a drawback of fluorescent lamp illumination, and to provide a color C
An object of the present invention is to provide an illuminating device that enables easy and accurate area extraction from a color image captured by a CD camera, and a final appearance inspection device for a printed wiring board using the illuminating device.

[0007]

An illumination device according to claim 1 of the present invention is an illumination device used for extracting an arbitrary region from a color image photographed by a color CCD camera. This is a lighting device that enables imaging with fluorescent tube illumination by using a fluorescent tube with characteristics that match the sensitivity characteristics of a CCD camera, and the fluorescent tube illumination has high diffusivity and uniformity over a wide range of illumination. It has the advantages of high cost, low price, easy lamp replacement, etc., and is characterized by eliminating the drawback of low illumination.

The final appearance inspection device for a printed wiring board according to claim 2 of the present invention uses the illumination device according to claim 1 and can extract an arbitrary region from a color image taken by a color CCD camera. Is a final appearance inspection device for a printed wiring board, and by using a fluorescent tube having a characteristic matching the sensitivity characteristic of a color CCD camera as an illuminating device, the fluorescent tube illumination has a high diffusiveness and a wide range of illumination. It has the advantages of high uniformity, low cost, easy lamp replacement, etc., and is characterized in that accurate area extraction can be performed by eliminating the drawback of low illuminance.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is applied to an illumination device of a final appearance inspection device for a printed wiring board in the final step of manufacturing the printed wiring board. Hereinafter, regarding the embodiments of the present invention,
It will be described with reference to the drawings.

FIG. 1 is a view showing the outline of the arrangement of a final appearance inspection apparatus for a printed wiring board according to this embodiment. This printed wiring board final appearance inspection device photographs the printed wiring board after the solder resist printing process and the silk printing process with a color CCD camera, and photographs the created data and the printed wiring board which is considered to be a good product. Automatic for the purpose of automatic inspection of the solder resist of the printed wiring board and each pattern of copper and silk printing by comparing the created master image and the reference data created from the master image created from CAD data. It is a final appearance inspection device, and includes an inspection camera 1, a confirmation camera 2, a control processing unit 3,
It is composed of an inspection monitor 4, a confirmation monitor 5, a camera drive unit 6, a stage 7, a drive control unit 8, an illumination device 12, and the like.

The inspection camera 1 photographs the image of the printed wiring board to be inspected illuminated by the illumination device 12 and the image of the printed wiring board of good quality. After the inspection is completed, the confirmation camera 2 captures an image of the defective portion of the detected inspection-target printed wiring board. The control processing unit 3 performs image processing, data processing, mechanical control, etc., captures positional information of the stage 7, sends a control signal to the inspection camera 1, and RGB data of an image captured by the inspection camera. An image input / processing unit 10 for processing the data, a data storage unit 11 for storing various data such as inspection reference data and inspection parameters used for inspection, and inspection result data.
The inspection monitor 4 performs a man-machine interface such as setting various parameters in the inspection. The confirmation monitor 5 displays a defective portion image of the inspection target printed wiring board taken by the confirmation camera. The camera drive unit 6 moves the camera in the X-axis direction. The stage 7 fixes the printed wiring board to be inspected and the non-defective printed wiring board, and moves in the Y-axis direction. The drive control unit 8 receives a command from the wholesale processing unit 3,
The drive control of the camera drive unit 6 and the stage 7 is performed.

The image of the printed wiring board taken by the inspection camera 1 has a copper pattern portion, a silk printing portion, and a solder resist printing portion, and each area is extracted with R, G, and B value thresholds. The images are inspected with different inspection accuracy.

The illumination device will be described below. Figure 2
Is a sensitivity characteristic of a color CCD camera that images the printed wiring board in the final appearance inspection device for the printed wiring board.
A fluorescent tube having a characteristic matching this sensitivity characteristic is used for the lighting device of the present invention.

FIG. 3 is a front view and a side view showing an illumination device according to an embodiment of the present invention. This lighting device includes four fluorescent tubes 21 to 24 and a case 20 for fixing and supporting the fluorescent tubes. The case is a quadrangular prism with one side open, and both ends of the fluorescent tubes 21 to 24 are supported by the bottom surface of the case via adapters.

[0015]

As described above, according to the present invention, by using the fluorescent tube which has the sensitivity characteristic of the color CCD camera,
The effect of supplementing the low illuminance, which is a drawback of fluorescent tube illumination, and solving the problem of extracting each region in the inspection is achieved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a final appearance inspection device for a printed circuit board.

FIG. 2 is a sensitivity characteristic of a color CCD camera.

FIG. 3 is a front view and a side view showing a lighting device.

[Explanation of symbols]

1 Inspection camera 2 Confirmation camera 3 Control processing unit 4 Inspection monitor 5 Confirmation monitor 6 camera drive 7 stages 8 Drive control unit 9 Camera controller 10 Image input / processing section 11 Data storage 12 Lighting device 20 Lighting device case 21 Fluorescent tube 1 22 Fluorescent tube 2 23 Fluorescent tube 3 24 Fluorescent tube 4

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koichi Yonekura             3-20-1, Tenjin Stock Exchange, Koga City, Fukuoka Prefecture             Inside the Shoga Electric Works Koga Plant F term (reference) 2G051 AA65 AA90 AB20 BA20 CA04                       EA17

Claims (2)

[Claims] 1. An illumination device used to extract an arbitrary region from a color image captured by a color CCD camera, which uses a fluorescent tube having characteristics matching the sensitivity characteristics of the color CCD camera. An illumination device that enables imaging with fluorescent tube illumination. 2. A final appearance inspection device for a printed wiring board, which uses the illumination device according to claim 1 and is capable of extracting an arbitrary region from a color image taken by a color CCD camera.