JPS61213709A - Method for inspecting appearance of electronic parts - Google Patents

Abstract

PURPOSE:To detect the flaw of a lead with high reliability, by applying illumination to the lead of electronic parts from the side opposite to the image pick-up side of the lead to form the silhouette image of the lead and picking up said image by a TV camera to detect the flaw of the lead. CONSTITUTION:Objective part 1000 are successively set in the visual fields of TV cameras 1005, 1006 for the purpose of inspection by a supply rail 1009 and a feed-out rail 1010. The illumination light generated by a light source 1007 transmits through light guides 1003, 1004 to be allowed to irradiate a diffusion reflective body 1002 from both ends of said guides. Therefore, the TV cameras can pick up the silhoutte image of the lead. The image signals of the TV cameras are supplied to an image processor 1008 and the number of white picture elements in the window region generated on the basis of the reference position of the parts of which the image is picked up are counted at every region and, if the counted value is smaller than a definite value, the presence of a bent lead in said region is judged to judge the parts as an inferior one.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for inspecting the appearance of electronic components, and particularly to a method for inspecting the appearance of electronic components.
The present invention relates to a lead visual inspection method suitable for detecting defects in the shape of leads and defects in single bends in a dual-line electronic component inspection process.

[Background of the invention]

Conventionally, as described in Japanese Patent Laid-Open No. 59-28353, a visual inspection was performed by an operator, and the electronic component feeding mechanism was improved so that the electronic component could be clearly seen by the operator. However, visual inspection by one worker was abolished,
No consideration was given to how to automate it.

[Purpose of the invention]

The purpose of the present invention is to prevent lead bending and breakage of electronic components.

An object of the present invention is to provide an external appearance inspection method for electronic components that automatically detects defects such as shape defects with high reliability.

[Summary of the invention]

Defects such as bent, broken, and poor shape leads of electronic components are defects related to the shape of the leads. The shape, or contour, can be determined by obtaining a silhouette image. Therefore, illumination is applied to the leads from the opposite side of the imaging side of the leads, darkening the leads and brightening the background of the leads to create a silhouette image of the leads with good contrast.Next, this silhouette image is captured with a TV camera. , automatically determines whether the lead has deviated from its intended predetermined position.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. It is composed of an imaging device for imaging a plurality of leads or a single lead of the target part 1000, an illumination device for obtaining a silhouette image of the leads, and an image processing device for detecting defects in the leads from the captured lead images. The imaging device used in this embodiment includes a -dimensional line sensor and a TV camera.

The configuration is such that two TV cameras shown at 1005 and 1006 are used to capture lead images. Illumination light generated by light source 1007 is transmitted through light guides 1003 and 1004.

The diffuse reflector 1002 is irradiated from both ends thereof. Therefore, the TV camera can capture a silhouette image of the lead, making the lead dark and the background image bright.

Image processing device 1008L: , TV camera 1005.
A video signal 1006 is supplied, a lead defect is detected, and the determination result 1011, that is, whether the target part is a good product or a defective product is output. The target parts are supply rail 1
009 and delivery rail 1010 to set within the field of view of the TV camera for sequential inspection.

In FIG. 1, the mechanism section and control section for supply and delivery are omitted.

FIG. 7 is a diagram illustrating the optical properties of the diffuse reflector 1002 for obtaining a lead silhouette image.

End surfaces 7008 and 7009 on which illumination light 7006 and 7007 from the light source 1007 are incident are transmissive surfaces. Further, the upper surface 7005 and the lower surface 7004 are completely reflective surfaces (mirrors) by performing a vapor deposition process, and the surfaces 7003 and 7002, which serve as the background of the leads, are diffusing surfaces. A diagonal surface 7001 is a total reflection surface that reflects the incident light.

FIG. 3 is a diagram illustrating an optical path transmitted through the diffuse reflector 1002. The light ray 3000 that has been transmitted through the light guide 1003 while repeating reflection is transmitted to the diffuse reflector 100.
2, the total reflection surface 7
The light reflected by 001 becomes scattered light 3012.3013. A silhouette image of the lead is obtained by scattering light from behind the lead. Lead 3001.3002.30
03° 3004 is configured to be imaged by the TV camera 1006, and leads 3005°, 3006, 3007, and 3008 are imaged by the TV camera 1005.

Figure 4 is based on the lead image taken with a TV camera.
FIG. 3 is an explanatory diagram of a method for extracting lead defects. An image 4012 shows a binarized read image captured by a TV camera. A portion 4001 corresponding to the background of the lead becomes brighter. Also, the lead 4010 and the portion 40 where there is no diffused light
00.4009 becomes dark. now.

It is assumed that lead 4010 is a normal lead. Further, the lead 4011 is assumed to be a lead with a bent defect. Window areas 4002 to 4008 are generated on the screen. This window area is
Occurs around the lead, based on the normal lead position.

For example, lead 4010 is window area 4002.4003
There are no leads or dark areas. However.

Window area 40 corresponding to lead 4011 with bending defect
05, 4006, a part of the dark part enters the window area 4006.

Therefore, lead defects can be detected by counting the number of white pixels or black pixels in this window area.

FIG. 5 is a configuration diagram of the image processing device 1008.

A video signal of one TV camera is selected by a circuit 5000 for selecting - of a plurality of TV cameras 1005 and 1006, and then an image binarization circuit 5001 selects the video signal.
The video signal is binarized and stored in the image memory 5002. Window area generation circuit 5003 generates window areas 4002 to 4009 shown in FIG. 4, and supplies their address coordinates to image memory 5002. As a result, certain pixel data within the window area are sequentially read out from the image memory 5002 and sent to the white pixel number counting circuit 5004. In the circuit 5004, the number of pixel data of 1, that is, the number of white pixels, is counted for each window area. The count value of each window area is sent to the count value determination circuit 5005, and if the count value is a constant value,
If it is smaller, it is determined that there is a bent lead in that window area, and the product is defective.

The determination result 1011 is reported to the operator or sent to the control unit, which is omitted in this embodiment.

FIG. 6 is a diagram showing the procedure of the present invention. Step 60
00, the lead image is binarized and stored in the image memory. Next, in step 6001, a window area is generated in the image based on the standard lead position, and step 600
2, the number of white pixels within the window area is counted. step 600
In step 3, it is determined whether the count value is larger than a predetermined value, and if the number of white pixels is smaller than the predetermined value, step 6
At 006, the target component is determined to be defective. On the other hand, if the count value is thicker than the predetermined value, in step 6004, steps 6001 to 6001 are performed in all window areas.
It is checked whether the processing up to 03 has been completed, and if the processing has not been completed in all window areas, the process returns to step 6001. Furthermore, when the process is completed in all window areas, the target part is determined to be a good product in step 6005.

FIG. 2 is a diagram illustrating another example of the configuration of the diffuse reflector 2006. The diffusing surfaces 2003 and 2004 are set on the slopes of the V-shaped grooves, and the incident light 2004 from below is scattered by the diffusing surfaces 2003 and 2004, and the transmitting surface 20
From 01 and 2002, the background of the lead will be illuminated. Upper surface 2000 is a total reflection surface. In this example,
Illumination light is supplied from below.

FIG. 8 is a diagram illustrating another example of the configuration of the diffuse reflector 8000. Light emitting elements 8003.8004.8005.8006.8007 are inside the diffuse reflector 8000.
．． 8008, 8009, and 8010 are installed, and the light emitting elements apply illumination to the diffusion surfaces 8001 and 8002. This illumination light is scattered at the diffusing surface 8001.8002 and leads 3001.3002.3003
．． 3004.3005.3006゜3007, 3008
Illuminated from behind. The silhouette image of the lead is on TV
Images are taken by cameras 1005 and 1006.

FIG. 9 is a diagram illustrating another embodiment of the diffuse reflector 1002, in which air bubbles 9 are formed in a transparent material such as glass or plastic.
000 is mixed in, and the incident light 90 (11) is diffusely reflected by the bubbles.The side surface of the reflector 1002, which becomes the background of the lead, is a diffusing surface.
If the mixing density is high, one normal transmission surface may be sufficient. moreover,
As a substitute for air bubbles 9000, small pieces of metal may be incorporated into the transparent body.

〔Effect of the invention〕

According to the present invention, defects such as bends and breaks in leads can be detected extremely quickly and with high reliability, and the processing equipment required is simple, thereby automating the visual inspection process of electronic components and improving reliability. It has a great effect on improvement and economicization.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a lead defect detection method. Figure 2 is a diagram explaining the optical properties of another embodiment of the diffuse reflector, Figure 3 is a diagram explaining the optical path transmitted through the diffuse reflector, and Figure 4 is a diagram explaining the window area of the lead image. 5 is a block diagram of the image processing device, FIG. 6 is a diagram showing the defect detection procedure, FIG. 7 is a diagram explaining the optical properties of the diffuse reflector, and FIGS. 8 and 9 are diagrams showing the procedure for defect detection. FIG. 2 is a diagram showing the configuration of another embodiment of the diffuse reflector. 1000...Target part, 1001...Lead, 10
05...TV camera, 1002...diffuse reflector,
100g... Image processing device, 4002... Window area,
4010... Normal lead image, 4011... Lead image with bending defect, 5003... Window area generation circuit. Child 1st 2nd mouth 3 ro'f1 φ eye'fI t eye\, 7th

Claims (1)

[Claims] 1. Generate a silhouette image of an electronic component by illumination, capture an image of the silhouette image, generate a plurality of window areas based on the reference position of the imaged electronic component, and create a white area within the window area. Alternatively, a method for inspecting the appearance of electronic components, comprising counting the number of black pixels and comparing the counted value with a predetermined value.