JPS61129512A - Inspecting instrument for curvature of lead - Google Patents

Abstract

PURPOSE:To detect the inward or outward curvature of an IC lead by providing a couple of linear image sensors so that the same part of the IC lead is viewed in different directions. CONSTITUTION:The linear image sensors 13a and 13b observe leads A0-A6 on the same line (h) from different positions which are at distance larger than IC width. The sensors 13a and 13b observe tips of the leads A0-A6 and their output signals are binary-coded by binarization circuits 15a and 15b by using a proper threshold level, obtaining information on the leads A0-A6. A central processor 7 calculates the center position of each lead from the binary-coded image data on, for example, the leads A1-A5, find lead intervals from the position information, and further computes the difference of the leak intervals. The processor 7 makes a large/small decision on the interval difference to decide whether the leads curve or not. Thus, the dead area is eliminated by using two linear sensors and then lead curvature in any direction is detected. Further, the processing of data is simple and decision making is attained at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a visual inspection of an IC, and particularly to an apparatus for detecting bent leads of an IC.

[Conventional technology]

A conventional device of this type is shown in FIG. In Figure 5,
1 is the IC guide, 2 is the IC to be inspected, and 3 is the IC
2 (7) Take images ■TV camera, 4 is light source for lighting, 5
is a sampling binarization circuit that samples and binarizes the video signal from the ITV camera 3 and outputs binary image data;
6 is an image memory that stores binary image data; 7 is a read AO-A from the binary image data stored in the image memory 6;
Find the tip point of 6 and read AO from the spacing of the tip points etc.
This is a central processing unit that detects bends in A6.

Next, the operation of the apparatus configured as described above will be explained. When the IC 2 that has been sent over the IC guide 1 comes in front of the field of view of the ITV camera 3, its image is read. Since the lead AO'-A6 has a metallic luster and the mold part is made of black resin, if the IC guide 1 is made of a material with poor reflectance and appropriate lighting is provided to the IC2, the lead AO-A6 can be Only the reflected light can be made into strong reflected light. In this case, in the binary image data output from the sampling binarization circuit 5, as shown in FIG. The data is as follows. In this way, only leads AO to A6 can be extracted.

The binary image data output from the sampling binarization circuit 5 is input to the image memory 6 and stored therein. The central processing unit 7 processes this binary image data and reads AO~
Find the tip coordinates of A6 or the center coordinates of lead AO-A6, and then calculate the lead spacing DOI shown in Figure 6 from the coordinates.
, 012. D23. D34. D45 and D56 are determined, and a widening of the lead interval or pinching is detected, and it is determined whether or not the leads AO-A6 are bent.

[Problem that the invention seeks to solve]

In such a conventional device, since the lead AO-A6 is observed from a position directly facing the side surface of the IC2, it is possible to detect bending in the pitch direction of the lead, but there is a problem that bending inward or outward cannot be detected. Yes, also 2
Since the lead position is determined by processing dimensional coordinates, there is a problem in that complex image processing is required.

The present invention has been made in view of these points, and its purpose is to provide a device that can detect not only the bending of the lead in the pitch direction but also the bending inward and outward, and which is easy to process. It's about doing.

Means for Solving Problem C] To achieve such an object, the present invention provides a pair of one-dimensional image sensors configured to view the same part of the lead from different directions, and a pair of one-dimensional image sensors. A binarization circuit that binarizes the signal output from the sensor, an image memory that stores the binarized signal as binary image data, and determines the quality of the lead from the binary image data in this image memory. A central processing unit is also provided.

[Effect]

In the present invention, from two types of information with different observation positions,
It is determined whether or not the lead is bent.

〔Example〕

A first embodiment of the lead bending inspection device according to the present invention is described below.
As shown in the figure. In FIG. 1, 13a and 13b are one-dimensional image sensors, and 15a and 15b are binarization circuits that binarize the video signal output from the one-dimensional image sensors 13a and 13b. In FIG. 1, the same or equivalent parts as in FIG. 5 are given the same reference numerals.

Next, the arrangement in this embodiment will be explained.

The -dimensional image sensors 13a and 13b observe the same line h of the tips of the leads AO to A6 shown in FIG. 1 from different positions at a distance sufficiently long compared to the IC width.

At this time, the -dimensional image sensors 13a, 13b and the IC
2 and 2 should be equally spaced from each other. In addition, the observation target is a portion at the same position from the tip of the lead for all leads.

The operation of the apparatus configured and arranged in this way will be explained using FIGS. 1 to 3. As shown in FIG. 1, the tips of the leads AO to A6 are observed using the -dimensional image sensors 13a and 13b, and the output signals are set to 2 at an appropriate threshold level.
When the data is binarized using the digitizing circuits 15a and 15b, information as shown in FIG. 2 or 3 is obtained. Figure 2,
In FIG. 3, the number "1" in the frame indicates the lead part, and the number rOJ indicates the background thereof. FIG. 2 shows information when the leads A1 to A5 are not bent, and the lead spacing between the leads A1 to A5 is 012. D23.
D34. All D45s have regular dimensions, l.

In FIG. 2, information regarding leads AO and A6 is omitted. Figure 3 shows information when lead A2 has a bend, and the lead spacing D of lead Al-7A5.
12, D23. D34. D45 is l-α, l+α.

1, e. The central processing unit 7 calculates the center position of each lead from the binary image data of leads A1 to A5 as shown in FIGS. 2 and 3, and calculates the lead interval D from the position information.
12. D23. D34. D45 is determined, and then the difference in lead spacing is calculated. In the case of the lead spacing shown in FIG. 2, the difference is D12-D23=D23-D34'=D34
-045=O, and as shown in Figure 3, if the lead spacing D12 and D23 deviate from the normal dimensions,
D12-D23=<1-α)-(l+α)=-2α
, D23-D34=<1+α)-l=α,D
34-D45=1-1=Q, which may deviate from rOJ. The central processing unit 7 determines the magnitude of this difference and determines whether or not there is lead bending.

Since lead bending is determined in this manner, if two -dimensional image sensors are used to eliminate blind spots, lead bending in any direction can be detected.

FIG. 4 is a diagram showing the line-of-sight planes of the -dimensional image sensors 13a and 13b and the positional relationship of the leads AO-A6,
The figure shows a state in which lead A2 is bent.

As described above, in this embodiment, a blind spot is eliminated by using a pair of one-dimensional image sensors, so that bending of the lead in any direction can be detected, and data processing can be easily performed and judgment can be made at high speed.

Furthermore, by calculating the difference in lead spacing, it is possible to calculate twice the deviation of the lead spacing from the normal dimension, so that highly accurate determination can be made.

〔Effect of the invention〕

As explained above, the present invention eliminates blind spots in detection by using a pair of one-dimensional image sensors that are set to view the same part of an IC lead from different directions, so lead bending in any direction can be detected and data can be This has the effect of making it easy to process and make decisions quickly.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a lead bending inspection device according to the present invention, FIGS. 2 and 3 are image data diagrams showing binary image data, and FIG. 4 is a line-of-sight plane of a one-dimensional image sensor. 5 is a configuration diagram showing a conventional lead bending inspection device, and FIG. 6 is a binary image diagram of the conventional device. 2...IC, 4...Light source for illumination, 6...Image memory, 7...Central processing unit, 13a, 13
b... Image sensor, 15a. 15b... Binarization circuit, AO-A6... Lead, DOI, D12. D23. D34. D45, D5
6...Lead interval.

Claims (1)

[Claims] a pair of one-dimensional image sensors configured to view the same part of an IC lead from different directions; a binarization circuit that binarizes the signal output from the pair of one-dimensional image sensors; The quality of the lead is determined based on the image memory that stores the signal as binary image data, and the size of the difference in the interval between adjacent leads calculated from the lead position calculated from the binary image data in this image memory. A lead bending inspection device comprising: a central processing unit for determining lead bending;