JPS6214449A - Bend detecting method for semiconductor element lead - Google Patents

Abstract

PURPOSE:To detect with high precision the bend of a lead by a method wherein the bent portion of an external lead and its end are recognized by two TV cameras and the quantity of the bend is determined on the basis of the relative positioning of the lead end image and lead base image. CONSTITUTION:A TV camera 3 recognizes the position of the end 2a of an external lead 2 and a TV camera 4 recognizes the position of the bent portion 2b of the external lead 2. The lead end image and the lead base image, covering the end 2a and the bent portion 2b, a picked up by the TV cameras 3 and 4, are respectively indicted by X/Y coordinates. The bend is represented by the difference between the two sets of coordinates. Computation is accomplished for each lead for the detection of the quantity of bend in the lead.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a lead bending inspection method for semiconductor devices.

[Conventional technology]

Conventionally, the inspection method by image processing using the TV left camera 4 is as shown in FIGS. 4(a) and 4(b).
By simultaneously performing image processing on the entire external lead 2 on each side, the quality of the external lead 2 is determined by comparing it with the data read from the reference sample.

[゛Problem that the invention attempts to solve]

The above-described inspection method using image processing using the conventional TV left camera 4 simultaneously Ki! !
! As the number of external leads 2 increases, the field of view needs to be widened in order to detect the external leads 2, and the precision per pixel deteriorates, resulting in the drawback that only a limited number of external leads 2 can be detected.

Furthermore, as shown in FIGS. 4(a) and 4(b), conventionally, the entire external lead 2 of the semiconductor element 1 is recognized at once from above or below and from the left and right sides using the TV left camera 4. The criteria for determining the relative position of the case and leads becomes unstable due to variations in the bending position due to the bending position, and sealing deviations in the sealing process between the lead frame and case in glass cases, etc., resulting in lead bending in the Y direction every time the product type or loft changes. The drawback was that the inspection accuracy was low.

The present invention provides a lead bend inspection method for individually inspecting lead bends in each lead of a semiconductor element.

[Failure to solve the problem]

The lead bend detection method of the present invention uses a TV camera to recognize the bent part and the tip of an external lead of a semiconductor device, obtain images of the tip of the external lead and the bent part, and detect the lead based on the relative position of both images. It is characterized by determining the curvature of.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. In Figure 1 (&) and (b), the TV camera 3
The tip position 2a of the external lead 2 is recognized by the TV camera 4, and the bent position 2b of the external lead 2 is recognized by the TV camera 4.

That is, each external lead 2 is recognized by two TV cameras 3.4.

In FIG. 2, the recognized position of a lead tip image 8 in which the tip 2a of the external lead 2 is recognized by the TV camera 3 is indicated by an X coordinate 9 and a Y coordinate 10. In this case, 6.7 is the monitor's X, Y coordinate reference line. 5 is a coordinate monitor.

In FIG. 3, the bent portion 2btl-TV of the external lead 2
The recognized position of the lead root image 11 recognized by the camera 4 is indicated by an X coordinate 12 and a Y coordinate 13.

The amount of deviation between the recognized coordinates of the lead tip image 8 and the lead base image 11 shown in FIGS. 2 and 3 is calculated as the lead bend amount for each lead, thereby detecting the lead bend.

〔Effect of the invention〕

As explained above, the present invention recognizes the bent portion and the tip of the external lead using two TV cameras in the lead bending inspection, and determines the relative position of the lead tip image and the lead root image as the amount of lead bending. , it is possible to accurately detect variations in the bending position in the lead bending process, sealing deviation in the sealing process, etc. Also, since the amount of bending of each external lead is determined one by one, there is no limit to the number of external leads. This has an effect that can be applied to a wide variety of lead bend detections.

[Brief explanation of drawings]

FIG. 1(a) is a side view showing the lead bend detection method of the present invention, FIG. 1(b) is a front view of the same, and FIG.
Figure 3 is a monitor diagram recognized by a TV camera, and Figure 4 is a monitor diagram recognized by a TV camera.
) is a front view showing the conventional method, and (b) is a side view of the same. DESCRIPTION OF SYMBOLS 1...Semiconductor element, 2...External lead, 3...TV camera for recognizing the tip of the external lead, 4...TV camera for recognizing the bent portion of the external lead, 5...Coordinate monitor, 6...
・Monitor X coordinate reference line, 7... Monitor Y coordinate reference line, 8... External lead tip image, 9... External lead tip X coordinate, 10... External lead tip Y coordinate, 11.
... External lead bent part image, 12... External lead bent part X coordinate, 13... External lead bent part Y coordinate O Patent applicant Kyushu NEC Co., Ltd. 〕 figure

Claims (1)

[Claims] (1) In the lead bend inspection of semiconductor devices, images of the bent portion and tip of the external lead of the semiconductor device are taken with a TV camera, images of the bent portion and tip of the lead are obtained, and the relative positions of the two images are taken. 1. A method for detecting lead bending of a semiconductor device, the method comprising inspecting the bending amount of a lead.