JPH01262637A - Visual inspection of semiconductor pellet - Google Patents

Abstract

PURPOSE:To automate inspection and the decision of the result of inspection by superposing the binary-coded picture of a pellet to be inspected to that of a reference pellet. CONSTITUTION:A video signal 12, the binary-coded picture 3 of the external shape of a pellet extracted from the signal 12 and the binary-coded picture 14 of a pellet electrode extracted from the signal 12 are registered previously regarding the reference pellet 11 of an LED. A video signal 22 and binary coded pictures 23, 24 are read similarly regarding a pellet to be inspected 21. The quantities of displacement are calculated by superposing each binary-coded picture regarding the external forms of each pellet and electrodes and matching rates to a reference pattern registered are computed, breaking, cracking, etc., are decided, and nondefective/defective are judged by the decision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for inspecting the appearance of semiconductor pellets, and is particularly applicable to a method of inspecting the appearance of semiconductor pellets having electrodes formed on their upper surfaces.

(Prior Art) An example of an LED pellet formed by a semiconductor device manufacturing process in which a semiconductor wafer is processed, processed, and divided to form semiconductor pellets (hereinafter abbreviated as pellets) is
The figure shows a front view, in which 101 is a pellet and 102 is an electrode formed on the main surface of the pellet.

The above pellet 101. During the manufacturing process, the electrode 102 on the pellet may be cracked, chipped, deformed, or damaged on the main surface of the pellet and the 111tf! What misalignment etc. will occur? Regarding these, in the visual inspection, the appearance v1. Visual inspection is performed using a mirror.

(Problem to be Solved by the Invention) According to the above-mentioned conventional technology, inspections such as pellet cracking, chipping, electrode deformation, and positional deviation of the electrode with respect to the main surface of the pellet are visually performed under a microscope. As a result, accuracy is affected by the skill level of the inspector, making inspection standards ambiguous, which is a serious issue that needs to be resolved.

The present invention was made to improve the drawbacks of the above-mentioned conventional techniques, and provides a method for automating inspection and judgment of its results.

[Structure of the invention]

(Means for Solving the Problems) A semiconductor pellet appearance inspection method according to the present invention registers a binary image of the external shape and electrode pattern of a semiconductor pellet set to a predetermined standard.

A binarized image of the outer shape and electrode pattern of the test pellet is read, and this binarized image is superimposed on the binarized image of the reference pellet to determine the amount of deviation between the outer shape and the electrode pattern, and the registered reference pattern. Judging whether there are any chips, cracks, etc. based on the matching rate against
This is used to judge defects.

(Function) The present invention can automate the visual inspection of semiconductor pellets, and can clearly determine whether the pellets are good or bad based on inspection standards.

(Example) An example of the present invention will be described below with reference to the drawings.

As shown in FIG. 1(a), for example, a video signal 12 is obtained for a (good quality) pellet serving as a reference for an LED.

A binarized image 13 of the pellet outer shape extracted from this video signal 12 and a binarized image 14 of the pellet electrode further extracted from the video signal 12 are registered. .

Next, as shown in FIG. 1(b), for the pellet ring to be tested, a video signal 22 and this video signal 22 are
A binarized image 23 of the pellet external shape extracted from the video signal 12 and a binarized image 24 of the electrode extracted from the video signal 12
Read. Next, as shown in FIG. 1(c), the binarized images of the pellet outline and electrode are superimposed to determine the amount of deviation and the matching rate with respect to the registered reference pattern, and the chipping is determined.

Cracks, etc. are determined, and a good/defective determination is made based on these.

That is, the above judgment is made by first comparing the binarized images 14.24 of each of the reference electrode pattern and the test electrode pattern with respect to chipping, dirt, etc. of the ffi electrode, and confirming that the amount of discrepancy 34 is within the limit. Determine whether or not (Fig. 1(a)) (...) σ1 for the pellet external shape.

Compare the binarized images 13.23 for each of the reference pellet pattern and the test pellet pattern, and determine whether the amount of mismatch is within the 33 limit (FIG. 1(b));
(Fast) The amount of deviation between the reference pellet and its electrode is 0 (-41
), but the outer shape pattern 2 of the test pellet is
It is determined whether or not the center-to-center deviation amount 25 between the electrode pattern 24 and the electrode pattern 24 is within a limit (FIG. 1(C)). Then, the results of the above items (i) to (iii) are combined to determine whether the product is good or bad.

Although the above embodiment has been described with respect to an LED chip, it is needless to say that the present invention is not limited to this and can be applied to a wide range of general semiconductor device chips.

〔Effect of the invention〕

According to the pellet appearance inspection method according to the present invention, it is possible to automate the inspection process, and it has the remarkable advantage that it can completely avoid the conventional problem of inspection accuracy being influenced by the skill level of the inspector and inspection standards being ambiguous. be.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating an embodiment of the present invention, in which (a) is a line diagram of a binarized image extracted for a reference pellet, and (b)
) is a line diagram of the binarized image extracted for the test pellet,
(C) is a diagram for checking the amount of deviation between the pellet and the electrode, and FIG. 2 is a front view of the pellet. 1-11 (reference) pellet 12 --- Video signal (of reference pellet) 13 ---
--- Binary image of pellet external shape 14 --- Binarized image of pellet electrode --- Test pellet 22 --- Video signal (of test pellet) 23 ---
-Binarized image of one test pellet external shape 24--Binarized image of one test pellet electrode 25-111 Amount of deviation between the centers of the pellet external pattern and electrode pattern in the test pellet 33-- --Amount of discrepancy between the pellet external shapes of the reference pellet and the test pellet 34-1--Amount of discrepancy between the electrodes of the reference pellet and the test pellet Agent Patent attorney Norihiro Ogo, +-Violation of spirit-F, :=-I 5 Nii Otsu A I Kamematsu: t)
；Niji binary ratio box f turtle Figure 1 [Vt 荊) (fZ) →

Claims (1)

[Claims] A binary image of the external shape and electrode pattern of a semiconductor pellet set to a predetermined standard is registered, and a binary image of the external shape and electrode pattern of the test pellet is read, and this binary image is transferred to the standard pellet. The appearance of the semiconductor pellet is superimposed on a binarized image, and chips, cracks, etc. are determined based on the amount of deviation between the external shape and the electrode pattern, and the matching rate with respect to the registered reference pattern, and the good/bad appearance of the test pellet is determined. Inspection method.