JPH05144915A - Image pick-up device for lead detection - Google Patents

Abstract

PURPOSE:To perform binary treatment of an image sufficiently and to detect an edge of a lead accurately by locating the leads of an IC package in the place to correspond to a slant mirror and by casting the illumination light on the rear face of the leads from a light source and by leading the light to an industrial camera. CONSTITUTION:An IC package 10 to be inspected is located on a stage 2. The stage 2 is provided with slant mirrors 3 facing downwards and slant mirrors 4 facing upwards which are located below the slant mirrors 3. The slant mirrors 3 face a lower end part of leads of the IC package 10 and face industrial cameras 7 located horizontally. The slant mirrors 4 face a light source 5 for illumination. In order to catch an image from above the IC package 10 and the leads 9, an industrial camera 8 is installed. By this method, an edge of the lead 9 can be discriminated in the image process and thereby an accurate binary image can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device for inspecting leads of an IC package by image processing.

[0002]

2. Description of the Related Art For example, as a lead deformation inspection of a flat type IC package, an electrode plate sandwiching method, an optical pulse train interval measuring method, a photo sensor on / off method, an image processing method, etc. have been proposed. In the methods other than the image processing method, only so-called lead bending is detected. However, the image processing method detects the edge of the lead, and thus, in addition to the lead bending, there is a variation in the vertical direction of the end portion of the lead. Since it is possible to measure variations in the protruding length of the leads when viewed from above the IC package, it is an excellent inspection method.

An appropriate image pickup device is required for such image processing. In the conventional imaging method, since an image of reflected light is taken by an industrial camera, binarization processing is insufficient in the process of image processing, and there is a problem in reliability of lead edge detection. It was

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks as a system for capturing an image with transmitted light instead of the system for capturing reflected light of an image.

[0005]

In view of the above object, the present invention places an IC package on the upper surface of a stage, places the leads of the IC package at positions corresponding to the tilt mirror integrated with the stage, and illuminates from below the tilt mirror. A light source for use is placed, and the illumination light from this light source is emitted from the back surface of the lead and guided to the industrial camera. According to such an image of the transmitted light method, the edge of the lead to be inspected becomes clear, so that the image processing is reliable and the inspection of the deformation of the lead is reliable.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an image pickup apparatus 1 for lead inspection according to the present invention.
Is shown. The IC package 10 to be inspected is mounted on the mounting surface 21 on the upper side of the I-shaped stage 2 when viewed from the front. The stage 2 has a downward tilting mirror 3 on both sides, for example, and an upward tilting mirror 4 below the tilting mirror 3. In addition,
The stage 2 is made of metal and is fixed on the base 11 to prevent electrostatic charge. The tilted mirrors 3 and 4 are formed in a state in which the surface of the stage 2 is mirror-finished so as to have a good reflection efficiency, and are usually tilted at 45 degrees with respect to the vertical line.

The tilted mirror 3 faces the lower end portion of the lead 9 of the IC package 10, and the industrial camera 7 in the horizontal direction.
Is facing. The lower tilt mirror 4 faces the light source 5 for illumination. The luminous flux from the light source 5 is
To prevent it from becoming scattered light, for example, an L-shaped optical path guide 6
Is guided from the light source 5 to the industrial camera 7 via the lower tilt mirror 4 and the upper tilt mirror 3. Then, the IC is placed above the IC package 10.
An industrial camera 8 is installed to capture the image of the package 10 and the leads 9 from above.

The leads 9 of the IC package 10 are of the J type, for example, and when the IC package 10 is placed on the mounting surface 21 of the stage 2, the lower ends of the leads 9 are
The tilt mirror 3 is located at a substantially intermediate position and faces the tilt mirror 3 and the industrial camera 7. In this state, the light source 5
When the illumination light is applied to the tilting mirror 4, the light flux strikes the lower tilting mirror 4 from the lower tilting mirror 4 to the upper tilting mirror 3 without being scattered to the outside by the optical path guide 6, and is reflected there to the industrial camera 7. Although it is guided, it is shielded from light by many leads 9 in the process. Therefore, when viewed from the industrial camera 7, the lead 9 is an image of a light flux from the rear surface, that is, transmitted light. Industrial camera 7 has lead 9
The image formed by the transmitted light is converted from an optical image into an image of an electrical signal, and the image is sent to an image processing device (not shown).

FIG. 2 shows an image of the transmitted light at this time. The tilted mirror 3 is brightened by the light flux for illumination, but the side surface of the IC package 10 and the leads 9
The outer surface of the appears as a dark area. Therefore, the image processing apparatus performs the binarization processing on the image, extracts the dark image from the light background, observes the shape on the image, and reads the lead 9
Deformation, that is, the inclination of the lead 9, the vertical variation of the lower end portion of the lead 9, the change in the protruding length of the lead 9 from the side surface of the IC package 10, and the like are measured and compared with a reference value to determine the quality. Judge.

At the same time, the industrial camera 8 on the upper side captures the upper surfaces of the left and right leads 9 together with the upper surface of the IC package 10, especially its outer diameter line, and sends it to the image processing apparatus as an image viewed from above. Illumination of the industrial camera 8 may be transmitted illumination by the light source 5, and illumination from obliquely above is used together with this transmitted illumination.

In the above embodiment, the IC package 10 is used.
Corresponding to the formation of the leads 9 on both sides of the, the industrial cameras 7 are provided on both sides. However, when the inspection of the left and right leads 9 is performed at different stations, the industrial cameras 7 The camera 7 will be provided corresponding to one lead 9. Further, when the deformation viewed from above the lead 9 is not an item to be inspected, the upper industrial camera 8 is omitted.

[0012]

According to the present invention, the lead of the IC package becomes a dark portion and the background is imaged as a bright portion. Therefore, the edge of the lead can be clearly discriminated in image processing, and an accurate binarized image can be obtained. In addition, since uniform illumination can be easily formed in the longitudinal direction of the IC package, there is no variation in illumination in the longitudinal direction of the leads, errors in edge detection of a plurality of leads are eliminated, and measurement reliability is improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional front view of an image pickup apparatus for lead inspection according to the present invention.

FIG. 2 is an explanatory diagram of an image by transmitted light by an image pickup device for lead inspection of the present invention.

[Explanation of symbols]

1 Imaging device for lead inspection 2 Stage 3 Tilt mirror 4 Tilt mirror 5 Light source 6 Optical path guide 7 Industrial camera 8 Industrial camera 9 Lead 10 IC package 11 Base

Claims (2)

[Claims] 1. An IC to be inspected on the upper surface of a stage (2)
A mounting surface (21) of the package (10) is formed, and a downward tilting mirror (3) is provided on the side surface of the stage (2) below the mounting surface (21). An image pickup device (1) for lead inspection, characterized in that a light source (5) for illumination is arranged below, and an industrial camera (7) is arranged in the horizontal direction of the tilt mirror (3). 2. An IC to be inspected on the upper surface of the stage (2)
A mounting surface (21) of the package (10) is formed, and a downward tilting mirror (3) and an upward tilting mirror (4) are provided on the side surface of the stage (2) below the mounting surface (21), A light source (5) for illumination is arranged at a position facing the tilt mirror (4), and a stage (is provided between the light source (5) and the lower tilt mirror (4) and the upper tilt mirror (3). An optical path guide (6) is provided so as to be opposed to 2), an industrial camera (7) is arranged in the horizontal direction of the tilt mirror (3), and an industrial camera (7) is provided above the placing surface (21). 8) An image pickup device (1) for lead inspection, wherein the image pickup device (1) is provided downward.