JPH06241741A - Lead inspection device - Google Patents

Abstract

PURPOSE:To make a lead appearance inspection such as the lead floating and pitch of an IC package with high precision with a simple structure. CONSTITUTION:An IC package 1 is put on an end plate 2, and the lead real image of the IC package 1 and the lead virtual image reflected on a mirror face are picked at the inclination angle within the range of 1 deg.-10 deg. against the horizontal plane of a CCD camera 6 picking a lead tip section 8 from the side direction of the IC package 1. The picked images are inspected by the pattern matching method. The inspection can be made with high precision with a simple lighting system while being rarely affected by the dust and burrs of the leads of the IC package 1. The optical system can be easily designed and adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead inspection apparatus for inspecting lead appearance such as lead floating and pitch of an IC package.

[0002]

2. Description of the Related Art As shown in FIG.
The package 1 is placed on the mirror plate 2, the CCD camera 6 is set at a certain angle of inclination with respect to the horizontal plane, and the lead real image of the lead tip portion 8 and the lead virtual image reflected on the mirror surface are captured. FIG. 4 shows an image captured by the method of FIG. 3, and shows the lower edge portion 2 of the lead of the real lead image 20.
3 and the upper edge portion 32 of the lead of the virtual lead image 30 are respectively detected, and the lead float H is calculated by calculating from the distance between the two points. When obtaining the lead pitch P, the lead pitch P is obtained by detecting the side edge portion 24 of the lead and the side edge portion 25 of the adjacent lead of the real lead image 20 and calculating the distance between the two points.

Further, as shown in FIG. 5, the IC package 1
Is placed on the stand 3, the CCD camera 6 is set at an inclination angle of 0 degree with respect to the horizontal plane, and the images of the lead tip 8 and the edge 11 of the stand are captured. FIG. 6 shows an image captured by the method of FIG. 5, in which the lower edge portion 23 of the lead and the flat edge portion 26 of the stand are respectively detected and
The lead float H is obtained by calculating the distance between the points. When the lead pitch P is obtained, the side edge portion 24 of the lead and the side edge portion 25 of the adjacent lead are respectively detected, and the distance between the two points is calculated to calculate the lead pitch P.
Are seeking.

[0004]

However, in the above-mentioned conventional example, since the method of detecting the edge portion is used, it is easily affected by dust and burrs. In FIGS. 4 and 6, if dust or burr is attached to the lead portion, an image 22 including the dust or burr is obtained. For example, when detecting the lower edge of the lead, the true lower edge is the position of the point P1, but the position of the point P2 is detected as the lower edge due to the influence of dust and burrs. Therefore, in the case of edge detection, there is a problem that dust and burrs directly affect the measurement error.

Further, when the edge detection is performed, the contrast between each lead tip image 27 and the image 28 of the other portion is strengthened, and the edge detection cannot be accurately performed unless the lead tip image 27 is captured as a very beautiful image. However, it is difficult to capture a clean lead tip image even if the diffusion plate 10 is used as shown in FIG. 3 and FIG.

In the case shown in FIG. 3, the CCD camera 6 is tilted to some extent, but the tilt angle is not clear, and it is necessary to investigate the influence of the tilt angle on the inspection accuracy each time and determine the tilt angle. It was

Therefore, the present invention solves the above-mentioned conventional problems, is less susceptible to dust and burrs, and has a simple structure for the illumination system, which enables highly accurate lead appearance inspection of the IC package. The purpose of the present invention is to provide a lead inspection device that can be easily designed and adjusted by clarifying the inclination angle of the CCD camera.

[0008]

In order to solve the above-mentioned problems, a lead inspection apparatus of the present invention is a lead inspection apparatus for inspecting the appearance of leads such as lead floating and pitch of an IC package, in which the IC package is placed on a mirror surface. , Said I
The image of the IC package is read by capturing the image of the actual lead of the IC package and the image of the virtual lead image reflected on the mirror surface when the inclination angle of the camera that captures the image of the lead from the side direction of the C package is in the range of 1 to 10 degrees with respect to the horizontal plane. A means for inspecting a lead real image and a lead virtual image of the IC package captured by using a pattern matching method is used to perform a lead inspection using image processing.

[0009]

Embodiments of the present invention will be described below with reference to FIGS.

In FIG. 1, an end plate 2 whose upper surface is a mirror surface is placed on a stand 3. The end plate 2 is fixed to the stand 3 by a fixture 4. The IC package 1 is placed on the end plate 2. The CCD camera 6 is attached at an angle A with respect to the horizontal plane, and the range of the angle A is 1 degree to 1 degree.
The range is 0 degree. A lens 7 is attached to the CCD camera 6 so as to have a predetermined magnification. An illumination 9 is attached in front of the lens 7 so as to illuminate the lead tip 8 of the IC package 1. Since the surface of the lead tip portion 8 does not usually have a uniform roughness, it is necessary to illuminate the lead tip portion 8 with a strong light amount in order to capture an image of the lead tip portion 8. Therefore, it is preferable to use a halogen light source as the light source of the illumination 9.

FIG. 2 is an image in which the lead tip portion 8 is captured by the CCD camera 6 with the configuration shown in FIG.
The lead real images 20 of the IC package 1 are captured in a row above the screen 40, and the virtual lead images 30 reflected on the mirror surface are captured in a row below the screen 40.

In order to measure the lead float H, first, a lead real image image 21 which is one of several lead real images 20 is registered in a memory for image processing, and the lead real image image 21 which is the reference is arbitrarily selected. Point Q1 is decided. Similarly, one of several lead virtual images 30 is registered as a reference read virtual image 31 in a memory for image processing, and an arbitrary point R1 is determined in the reference read virtual image 31. Next, based on the reference read real image 21 registered in the memory for image processing, several lead real images 20 captured in a row on the screen 40 are searched for by pattern matching and set as the reference. Points Q2, Q3, Q4, Q5 and Q6 corresponding to the point Q1 in the read real image 21 are obtained. Similarly, for the lead virtual image 30,
Based on the reference virtual lead image 31 registered in the memory for image processing, several lead virtual images 30 captured in a row at the bottom of the screen 40 are searched for by pattern matching and used as the reference virtual lead image. Point R in image 31
Points R2, R3, R4, R5, and R6 corresponding to 1 are obtained, respectively. Here, the lead float H can be obtained by calculating the difference between the Y coordinates of the point Q2 obtained from the lead real image 20 and the point R2 obtained from the lead virtual image 30 corresponding to the point Q2. Similarly, the floating of each lead can be obtained from the corresponding points of the read real image 20 and the read virtual image 30 such as point Q3 and point R3, point Q4 and point R4.

To measure the lead pitch P, the lead pitch P can be obtained from the difference between the X coordinates of the point Q2 in the real lead image 20 and the point Q3 of the adjacent lead. Similarly,
The pitch of each lead can be obtained by sequentially obtaining the difference between the X-coordinates of the adjacent leads such as the point Q3 and the point Q4.

When one side of the IC package 1 cannot be captured in an image on one screen, the CCD camera 6 is placed on the X-stage 5 which can be laterally fed, and the CCD camera 6 is moved in the lateral direction to thereby move the IC package. All leads on one side can be inspected. The same can be said when the stand 3 on which the IC package 1 is placed is placed on the X-stage which can be laterally fed.

Reed real image 20 and lead virtual image 3 respectively.
When searching for 0 by pattern matching, even if the lead image 8 has dust or burrs and the captured image is the image 22 containing dust or burrs, it is based on the reference real lead image 21. Therefore, when the pattern matching is performed, the image 22 including dust and burrs has a low degree of similarity to the reference real lead image 21, but a point Q6 corresponding to the point Q1 in the reference real lead image 21.
Does not affect the position of. Therefore, there is an advantage that it is not directly affected by dust and burrs.

If the mounting angle of the CCD camera 6 is within the range of 1 to 10 degrees with respect to the horizontal plane, the measured value of the lead float H will be a substantially constant value.

When the illumination is attached, the lead real image 20 and the lead virtual image 30 can be obtained by pattern matching even if contrast is not so strong between the lead portion and other portions.
Can be found, so a simple configuration is sufficient.

[0018]

As described above, the lead inspection apparatus of the present invention puts the IC package on the mirror surface, captures the lead real image and the lead virtual image of the IC package in the image, and performs pattern matching to thereby remove dust, burrs, and the like. The illumination system can be inspected with high accuracy with a simple structure. Further, since the tilt angle of the CCD camera is made clear, there is an effect that the design and adjustment are easy.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a lead inspection apparatus of the present invention.

FIG. 2 is a diagram showing a captured image of the lead inspection apparatus of the present invention.

FIG. 3 is a diagram showing a configuration of a conventional lead inspection device.

FIG. 4 is a diagram showing an image captured by a conventional lead inspection apparatus.

FIG. 5 is a diagram showing a configuration of a conventional lead inspection device.

FIG. 6 is a diagram showing a captured image of a conventional lead inspection apparatus.

[Explanation of symbols]

 1 ・ ・ ・ IC package 2 ・ ・ ・ End plate 3 ・ ・ ・ Stand 4 ・ ・ ・ Fixing tool 5 ・ ・ ・ X-stage 6 ・ ・ ・ CCD camera 7 ・ ・ ・ Lens 8 ・ ・ ・ Lead tip 9 ..Illumination 10 ... Diffusion plate 11 ... Edge of stand 20 ... Real image of lead 21 ... Real image of lead image 22 ... Image containing dust and burrs 23 ... Lead Lower edge part 24 ... Lead side edge part 25 ... Adjacent lead side edge part 26 ... Stand flat edge part 27 ... Lead tip image 28 ... Other part image 30 ... Lead virtual image 31 ... Reference lead virtual image image 32 ... Lead upper edge portion 40 ... Screen

Claims (2)

[Claims] 1. A lead inspection apparatus for inspecting lead appearance such as lead float and pitch of an IC package, wherein the IC package is placed on a mirror surface and a tilt angle of a camera for capturing an image of a lead portion from a side direction of the IC package is set. The lead inspection of the IC package is performed by image processing by capturing an image of the lead real image of the IC package and an image of a lead virtual image reflected on a mirror surface within a range of 1 to 10 degrees with respect to a horizontal plane. apparatus. 2. The lead inspection apparatus according to claim 1,
A lead inspection apparatus for inspecting a captured image of a lead real image and a lead virtual image of the IC package by using a pattern matching method.