JPH04310808A - Inspecting apparatus for external appearance of solder - Google Patents

Abstract

PURPOSE:To facilitate determination of the quality of a soldered state and to reduce a mistake in determination by generating an inspective window at a back fillet of a lead. CONSTITUTION:An illuminating element 4 applying an illuminating light 3 to a back fillet part of a lead of a package component 2, cameras 6 to 9 provided aslant for taking in a reflected light 5, A/D conversion circuits 10 to 13 converting image data into digital values, a window generating circuit 15 generating an inspective window 14 at a back fillet part of the component 2, and a determination circuit 16 determining the quality, are provided. When the illuminating light is applied to the back fillet part of the lead, a strong reflected light 5 returns and the total sum of output data inside the inspective window 14 becomes large when soldering is good, while the sum becomes small when the soldering is bad. The determination circuit 16 determines an article as good when the total sum of the digital output data inside the inspective window 14 is larger than a threshold value, while determining the article as bad when the sum is smaller.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering appearance inspection apparatus.

0002

[Prior Art] As a conventional technique, for example,
There is an inspection device as shown in Publication No.-10251.

As shown in FIG. 4, this inspection device includes a ring-shaped illumination device 20 that illuminates a component 2 mounted on a printed circuit board 1, a camera 21 that captures an image of reflected light, and a camera 21. It has a binarization circuit 22 that binarizes output data of , an area extraction circuit 23 that extracts a bright area of reflected light, and a determination circuit 24 that makes a pass/fail judgment from the output data of the area extraction circuit 23. .

The camera 21 captures the reflected light when the lighting device 20 irradiates the component 2 and converts the image data into a binarization circuit 2.
Output to 2. The binarization circuit 22 binarizes the image data. Here, if the soldered part is a good product, there will be a small number of large and bright areas in the binarized image data, and if the soldered part is a defective product, the binarized image data will be complicated and complicated. It is characterized by containing many small bright areas. Based on the above, the determination circuit 24 determines that the product is defective when the number of bright areas is large, and determines that the product is non-defective when the number of bright areas is small.

[0005]

[Problems to be Solved by the Invention] In the conventional technology described above, even when the soldered part at the tip of the lead is a good product, the fillet shape is complex and the number of bright areas in the image data is larger than when the soldered part is a defective product. This method has the disadvantage that there are many errors in determining pass/fail.

[0006]

[Means for Solving the Problems] The soldering appearance inspection apparatus of the present invention includes a lighting device that illuminates the back fillet portion of a lead of a surface mount component on a printed circuit board, a camera that takes in reflected light from the lighting device, and a camera that captures reflected light from the lighting device. A/D that converts the analog grayscale signal of the captured image into digital values.
A conversion circuit, a window generation circuit that generates an inspection window in the back fillet portion, and a pass/fail judgment circuit that compares the data obtained from the A/D conversion circuit with a pass/fail judgment standard to judge whether it is good or bad. be done.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a perspective view of the generation of an inspection window.

The soldering appearance inspection apparatus shown in FIG. 1 includes an illumination section 4 that irradiates illumination light 3 onto the back fillet portion of the lead of a mounted component 2 on a board 1, and a reflected light 5 obtained by the illumination light 3. Cameras 6 to 9 installed diagonally as shown in FIG. 2 for capturing, A/D conversion circuits 10 to 13 that convert image data a to d output from the cameras 6 to 9 into digital values, and 2, a window generation circuit 15 generates an inspection window 14 in the back fillet portion of the mounted component 2, and image data of reflected light within the inspection window 14, that is, output data e~ of the A/D conversion circuits 10 to 13. It is configured to include a determination circuit 16 that determines whether the soldering condition is good or bad based on h.

In FIG. 1, an illumination section 4 irradiates illumination light 3 onto the back fillet portion of a lead of a mounted component. Here, as shown in Figure 2, if the soldering part is good, strong reflected light 5 will return to the camera, but if the soldering part is defective, the reflected light 5 will be diffusely reflected and only weak light will return to the camera. do not have. Therefore, if the soldered part is a good product, the sum of the digital output data within the inspection window 14 will be a relatively large value, and if it is a defective product, it will be a relatively small value. The determination circuit 16 determines that if the sum of the digital output data within the inspection window 14 is larger than a preset threshold value, it is a "good product", and if the value is smaller, it is a "defective product".

0010

[Effects of the Invention] The soldering appearance inspection device of the present invention generates an inspection window in the back fillet of the lead instead of the fillet at the tip of the lead, making it easier to judge the quality of the soldering condition and improving the defect detection rate. It has the effect of

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a perspective view of inspection window generation.

FIG. 3 is a layout diagram of an oblique camera.

FIG. 4 is a block diagram showing a conventional example.

[Explanation of symbols]

1 Board 2 Mounted parts 3. Illumination light 4. Lighting section 5 Reflected light 6～9,21 Camera 10-13 A/D conversion circuit 14 Inspection window 15 Window generation circuit 16, 24 Judgment circuit 17 Lead 18 Solder 19 Pad 20 Ring-shaped lighting device 22 Binarization circuit 23 Area extraction circuit a~d Image data e~h Digital data

Claims (1)

[Claims] 1. A light that illuminates the back fillet of a lead of a surface-mounted component on a printed circuit board, a camera that captures reflected light from the light, and an analog grayscale signal of an image captured by the camera that is converted into a digital value. A
A/D conversion circuit, a window generation circuit that generates an inspection window in the back fillet portion, and a pass/fail judgment circuit that compares the data obtained from the A/D conversion circuit with a pass/fail judgment criterion to judge pass/fail. A soldering appearance inspection device characterized by: