JPH08152412A - Appearance inspection device - Google Patents

Abstract

PURPOSE: To achieve a stable inspection for distinguishing color difference and brightness difference with a sufficient resolution by providing a color coordinate conversion part, a color coordinate data retention part, an inspection data retention part, and a control means. CONSTITUTION: The image of the reflection light of a TAB tape 19 to be inspected is picked up by a color CCD camera 4 and the image is passed to a color image processing part 14 and is converted into brightness and chromaticity information by a color coordinate conversion part 15. In this case, inspection data retained at an inspection data retention part 18 are interpreted and color coordinate data are read from a color coordinate data retention part 18 based on data for specifying color coordinates described in the inspection data. The color coordinate data are passed to the color coordinate conversion part 15 and color coordinate conversion is performed according to an inspection target. The converted image information is subjected to binarization processing according to a binarization threshold stored at the retention part 18 for every picked-up image screen by a color extraction part 16 and is subjected to binarization image processing by a judgment part 8 to judge conformity/non- conformity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an appearance inspection apparatus for processing color images of a plurality of colors in the field of FA to judge the quality of electronic parts, cream solder, TAB tape, etc. on a printed circuit board. .

[0002]

2. Description of the Related Art Generally, TAB tapes and mounting boards are manufactured by automatic machines in most cases. When an automatic machine is used as described above, due to various factors, defective products such as lead etching defects and surface stains and scratches in the case of TAB tape, and printing defects and mounting defects in the case of mounting boards may occur. Therefore, the inspection process is indispensable in manufacturing.

However, if such inspections rely on visual inspections by inspection workers, it is not possible to completely eliminate the occurrence of inspection errors, and in recent years the size and pitch of the inspection object have become smaller and narrower. With the adoption of TAB tape, visual inspection has reached its limit.

Therefore, automatic inspection machines for TAB tapes and mounting boards have become important, but various companies have proposed various methods such as a black and white camera, a color camera, a three-dimensional camera and an X-ray camera. . Considering various performances such as accuracy, tact, and cost, the tact is particularly important in an in-line inspection machine, and an inspection by a color camera, which has a short imaging time and a large amount of information, is drawing attention.

A conventional mounting board inspection apparatus using a color image will be described below with reference to the drawings.

FIG. 4 shows a conventional device for inspecting a component mounting board by a color image, which is disclosed in Japanese Patent Laid-Open No. 62-180250. In FIG. 4, 1 is a printed circuit board to be inspected, 2 is an XY table on which the printed circuit board is placed, 3 is illumination for illuminating the printed circuit board, 4 is a color image capturing unit, and 5 is a signal from the image capturing unit. Processing unit, 6, 7,
Reference numerals 8, 9, and 10 denote an image input unit, an image processing unit, a determination unit, a memory, a control unit, which constitute the processing unit 5, 11 is an image controller, 12 is a table controller, and 13 is a determination result output unit.

With respect to the inspection apparatus for a component mounting board having such components, the relationship between these components and the operation thereof will be described below. First, the printed board 1 to be inspected on the XY table 2 is illuminated by the illumination 3 and the color image capturing section 4 captures an image. Then, the processing unit 5 that processes the signal of the image pickup unit 4 processes the image,
The determination result is output to the determination result output unit 12. At this time, in the processing unit 5, the output image signal of the image pickup unit 4 is sent to the memory 9 through the image input unit 6 and stored therein. The image signal thus stored in the memory 9 is judged to be good or bad by the image processing unit 7, the judgment unit 8, and the control unit 10, and is output to the judgment result output unit 13.

At this time, parts such as a board, electronic parts, and cream solder are distinguished by the difference in color information of each pixel. On the other hand, when the image is picked up by the black and white camera, the number of parts that cannot be identified increases because only the brightness information is used for identification. In this way, the conventional example of FIG. 4 realizes a component mounting board inspection apparatus using a color image.

[0009]

However, in order to distinguish the lead portion, the resist portion, the resin-sealed portion on the TAB tape, the component on the mounting substrate, and the like on the TAB tape by the above-described conventional configuration, it is necessary to distinguish them from the following. There is such a problem. Figure 2
FIG. 3 is a diagram in which chromaticity and luminance of each pixel when an image of a substrate is imaged are plotted. As can be seen here, the chromaticity information of most parts that must be distinguished is the maximum value of 10
%, And the brightness information of the lead part is very high. At this time, if the light amount of the illumination unit is increased to increase the resolution of chromaticity, the luminance of the lead unit is saturated, and the color extraction accuracy of the lead unit deteriorates. On the contrary, in order to improve the color extraction accuracy of the lead portion, it is necessary to reduce the light amount of the illumination portion, and the resist portion and the resin sealing portion cannot be distinguished. FIG. 3 is a diagram showing an example in which the amount of light is increased, and the lead portion is in a state close to white (R, G maximum). Generally, the CCD sensor of a color CCD camera is less sensitive to blue light than other colors, so that other colors (R,
When the gain is increased to the same signal level as in G), there is also a tendency that the noise amount relatively increases in the case of an object having a low signal level.

For this reason, there is a problem that it is difficult to obtain sufficient color resolution for both high and low signal levels in the case of the conventional image pickup means under normal light amount.

The characteristic of the human eye is the logarithmic characteristic,
The fact that the resolution of the difference in the hue of dark color is high is a phenomenon that matches this.

In order to solve the above problems, the present invention distinguishes the difference in color and the difference in brightness of the lead portion, resist portion, resin sealing portion and the like with sufficient resolution, and an appearance inspection capable of stably realizing quality inspection. A device is provided.

[0013]

In order to solve the above-mentioned problems, an appearance inspection apparatus of the present invention comprises an image pickup means for picking up a color image, and three primary colors of the object picked up by the image pickup means. Color coordinate conversion means for converting into a space of luminance and chromaticity, color coordinate data holding means for holding the calculation coefficient in the color coordinate conversion means, and inspection data holding means for holding the inspection data having the information of the inspection object. A control means for decoding the inspection data and switching to the operation coefficient data registered in advance in the color coordinate data holding means is provided.

Further, in the appearance inspection apparatus of the present invention, as an operation coefficient held in the color coordinate conversion means, in order to inspect an object to be inspected having high brightness, the light quantity sensitivity in the image pickup means is the darkest among the three primary colors. Holds the calculation coefficient that calculates the brightness only from and the calculation coefficient that calculates the brightness and chromaticity from other than blue, which has a low light intensity sensitivity to inspect an object with low brightness. In addition, a control means for immediately switching the calculation coefficient according to each inspected object is provided.

[0015]

The visual inspection apparatus of the present invention uses the color coordinate conversion system for calculating the brightness from only blue for the lead having a large signal level at the time of inspection, and for the resist having a small signal level and the resin sealing portion. Uses a color coordinate conversion system that calculates luminance and chromaticity from color signals other than blue, so that both the lead part and the resist part or resin encapsulation part can be accurately identified by the conventional method with a constant amount of incident light. It was possible to identify things that were difficult to do,
The quality of the inspection object can be inspected.

At this time, since the color coordinate conversion system is changed according to the inspection object, a sufficient resolution can be obtained for each color video signal output of the lead portion, the resist portion, the resin sealing portion and the like.

As described above, by providing the means for switching the color coordinate conversion system according to the inspection object, the resist portion and the resin sealing portion which have a small signal and require a high resolution, and the signal has a large luminance and the brightness is saturated. It is possible to easily and easily identify the lead portion and accurately inspect the quality of the lead, the resist, and the resin sealing.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the appearance inspection apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the arrangement of an appearance inspection apparatus according to the first embodiment of the present invention. In FIG. 1, 14 is a color image processing unit for performing color coordinate conversion and color extraction, 15 is a color coordinate conversion unit, 16 is color extraction means, and 17
Is color coordinate data holding means, 18 is inspection data holding means,
Reference numeral 19 is a TAB tape to be inspected.

With respect to the mounting board inspecting apparatus having such components, the relationship between these components and the operation thereof will be described below. In the first embodiment, the reflected light from the TAB tape 19 as the inspection target is imaged by the color CCD camera 4 for imaging. At this time, the illumination 3 or the diaphragm of the color CCD camera 4 is adjusted to a level at which a signal of an object having a small signal level such as resist or resin sealing can be sufficiently discriminated. The captured image is passed to the color image processing unit 14 and converted into luminance and chromaticity information by the color coordinate conversion unit 15. At that time, the control unit 10 controls the inspection data holding unit 1
The inspection data held in 8 is read, and the color coordinate data is read from the color coordinate data holding unit 17 based on the data designating the color coordinates described in the inspection data. The difficult-to-read color coordinate data is passed to the color coordinate conversion unit 15 to perform color coordinate conversion according to the inspection target. The image information converted by the color coordinate conversion unit 15 is converted by the color extraction unit 16 into
Binary processing is performed according to the binarization threshold value stored in the inspection data holding unit 18 for each imaging screen. Next, the determination unit 8 performs binary image processing to determine pass / fail.

Further, according to the second embodiment of the present invention, as the data held in the color coordinate data holding unit 17, the color coordinate conversion is performed only for the lead portion having a large signal level and only the blue color having a low light intensity sensitivity. The calculation data shown in the equation (1) is used, and for other resist portions and resin-sealed portions having a low signal level, the blue color, which is easily affected by noise when the signal level is low, is excluded. The operation data shown in the equation (Equation 2) for realizing the color coordinate conversion is used.

[0022]

[Equation 1]

[0023]

[Equation 2]

By sequentially switching the color coordinate conversion system according to the inspection object during the inspection in this way, it is possible to stably identify both the lead portion having a high signal level and the resist portion or resin sealing portion having a low signal level. It is possible to configure an appearance inspection device that performs inspection accurately and stably inspects the quality of leads, resists, and resin sealing.

[0025]

As described above, according to the present invention, in the inspection device for inspecting the quality of the electronic component mounting board or the TAB tape by using the color image capturing means of a plurality of colors, the color coordinate conversion is performed according to the inspection object. By providing the means for switching the coordinate data of the system, in the configuration using the normal image pickup means as in the conventional example, it is necessary to distinguish between the resist portion having a low signal level, the resin sealing portion and the lead portion having a high signal level. The contradictory problems can be overcome, and the color difference of the resist portion, the resin sealing portion, the lead portion and the like can be recognized with sufficient resolution, and the quality of the electronic component mounting board and the TAB tape can be stably inspected.

[Brief description of drawings]

FIG. 1 is a block diagram of a visual inspection apparatus according to first and second embodiments of the present invention.

FIG. 2 is a diagram showing a color distribution of leads, resists, and resin sealing parts on a TAB tape.

FIG. 3 Leads on the TAB tape when the amount of light is increased,
Diagram showing color distribution of resist and resin encapsulation

FIG. 4 is a block diagram of a conventional mounting board inspection apparatus.

[Explanation of symbols]

 1 Printed circuit board 2 XY table 3 Illumination 4 Color CCD camera 8 Recognition determination unit 10 Control unit 14 Color image processing unit 15 Color coordinate conversion unit 16 Color extraction unit 17 Color coordinate data holding unit 18 Inspection data holding unit 19 TAB tape

Claims (3)

[Claims] 1. An image pickup means for picking up a color image, a color coordinate conversion means for converting the three primary colors of the color of the object picked up by the image pickup means, and a color coordinate conversion means for changing the three colors.
An appearance inspection apparatus characterized in that the luminance is calculated only from the blue color having the most light intensity sensitivity in the image pickup means among the primary colors. 2. An image pickup unit for picking up a color image, a color coordinate conversion unit for converting the three primary colors of the object imaged by the image pickup unit, and a color coordinate conversion unit for selecting one of the three primary colors. An appearance inspection apparatus characterized in that brightness and chromaticity are calculated from a light amount sensitivity other than a bluish blue color, which is the most in the image pickup means. 3. Color coordinate conversion means, color coordinate data holding means for holding a plurality of types of calculation coefficients for calculating color coordinates, inspection data holding means for holding inspection data having information of the inspection object, The control data is provided with control means for decoding the inspection data and switching to the operation coefficient data registered in advance in the color coordinate holding means, and the control means immediately switches the operation coefficient according to each inspected object during execution of the inspection. The appearance inspection apparatus according to claim 1 or 2, wherein: