JPS5839373A - Pattern recognition device - Google Patents

Abstract

PURPOSE:To perform accurate pattern recognition by irradiating isolated points on a pattern to be recognized with light beam, and then judging the size and shape of an obtained split picture through a picture processing circuit. CONSTITUTION:Isolated points at some part of a semiconductor wafer where dicing is to be done are irradiated with light beam, and picked up by a TV camera 20 to obtain a composite picture of split pictures. The picture value is converted by a binary coding circuit 21 into a binary signal. The binary-coded signal is supplied to a white mask extracting circuit 24 through a smoothing circuit 23. The circuit 24 extracts a white mask from the smoothed picture and stored position coordinates in the white mask in a local memory circuit 25. Then, a mixing circuit 26 mixes all of the binary-coded signal, smoothed signal, and extracted signal of white-mask from the circuits 23-25 into one, and transfers the composite signal to a monitor display circuit 27. Consequently, accurate pattern recognition is performed accurately even with the resolution of a conventional TV camera.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pattern recognition device that is being put into practical use or being promoted in semiconductor manufacturing equipment and the like.

In general, visual pattern recognition is a technology that has recently attracted attention as an effective method for saving labor in production. Taking the case of semiconductor manufacturing as an example, visual pattern recognition (hereinafter simply referred to as pattern recognition) will be described as follows. That is, as the schematic configuration is shown in FIG. 1, for example, in order to automate the positioning of the object to be recognized, a light beam 3 in the shape of a beam is irradiated onto the object to be recognized from the light source 2, and the TV
A camera 4 takes a picture, converts the video signal from analog to digital, and transmits it to an image processing circuit 6 via a binarization circuit 5, which converts the video signal into a binary value, detects the deviation from the target position, and However, in this pattern recognition, the resolution of the TV camera 4 is not sufficient to judge the minute traces of the image. Furthermore, if an attempt was made to solve the problem by improving the functionality of the image processing circuit 6, there would be problems such as the difficulty in manufacturing the circuit elements, resulting in high costs and lack of practicality.

This invention is proposed in consideration of the above ode, and is capable of providing a pattern recognition device that has sufficient functions even at the resolution of the current TV camera. A pattern recognition device that irradiates each point with a light beam, inputs each to a TV camera to obtain a composite split image, and determines the size and shape of the sprint image by an image processing circuit that detects and performs calculation processing of position coordinates. It is characterized by Next, a specific embodiment of the present invention will be described.

As an example, the application to dicing work for cow conductor wafers will be described, or the conventional dicing work based on the premise will be explained. FIG. 2 shows an example of a multi-i inverted mesa power transistor element 8.8. . . . The dividing line that divides into sections, that is, the dicing schedule II9.91
The third diagram shows the detailed circle A enlarged along ...
As shown in the figure, bevel esotinge mI0,1(1,...
...is established. Then, in order to perform pattern recognition, the wafer is temporarily fixed and placed on a transparent M-transparent die, and a parallel light beam is irradiated from below the die to form the bevel-etched grooves 10, 10. . . . is provided, and the planned dicing lines 9, 9 for wafers are
．． . . . Only the portions to be diced 11, 11 . While forming a rough pattern of..., irradiate light from a separate light source onto the wafer from above,
Pattern recognition is performed by photographing with a T4 camera in the same manner as shown in FIG. ...... The following sprint image is obtained based on the outline pattern.

That is, the desired two points B of Wehno shown in FIG.
Images B' and C'' obtained by photographing the details including O, respectively, are
As shown in Fig. 4), a composite image is created by combining the upper half image and the lower half image.Therefore, as shown in Fig. 4m), the dicing area 11, that is, the wafer, is transmitted from below. The electric signal level, that is, the white level, formed by photoelectric conversion by the TV camera in the part where the light penetrates, and the electric signal level, that is, the black level, that is formed only by the light reflected from above to the wafer in the part 12 that is not diced. In order to display the ry coordinates of the area 11 to be diced, which will be the white level, a TV camera is used to draw the binarized image on the display, and as described below, the microcomputer etc.・Make the grade 1. In other words, the principle of this invention is that, as shown in the fourth □□□ knowledge, the dicing scheduled area llc/) is the white level generation area (hereinafter referred to as white mask W).
A column line 13 of several focuses along the y-axis direction of the image,
2 i(
t< conversion information, that is, the starting frame of line 13, the final coordinates, and the width dimension of the white mask W are memorized and determined, and the white mask W is
This involves calculating the center line and the inclination with respect to the y-axis direction.

FIG. 5 is a block diagram showing a schematic configuration of a pattern and 78 recognition device showing an embodiment of the present invention, and 2Q is a
A camera 21 is a known binarization circuit that binarizes the digital signal transferred from the data bus of the microcomputer while comparing it with an analog video signal of the TV camera.・A synchronization signal generation circuit that generates a drive signal that serves as a vertical scanning reference, an external synchronization signal, and a memory edge signal to be stored in a microcomputer, 23tI'i, to make the binary signal stricter 24 is a circuit for extracting a required white mask from the smoothed both image signals; 25 is a local memory circuit for storing position coordinates in the white mask;
26 is a binary signal and a smoothed signal.

This is a mixing circuit for mixing and synthesizing all the white mask extraction signals and transmitting the result to the monitor display circuit 27.

Next, the outline of each circuit will be explained with reference to block diagrams. First, FIG. 6 is a block diagram of a binarization circuit, in which digital data 29 transferred from a data bus of a 28Fi microcomputer is
4 a video signal from the camera and a digital-to-analog conversion circuit provided for the purpose of making it comparable for binarization; 30 is the video signal which is raw analog information obtained from the TV camera; 31 is the video signal; 32 is an amplifier that also serves as a buffer; 33 is a digital-to-analog converter; A comparator that discriminates whether or not the level exceeds the level and outputs the white level or black level as a binary signal 34, and 35 selects and switches between the video signal 30 and the binarized signal 34, and synchronizes with an external block. This is a merging switching circuit that selects various synchronization signals, cursor signals, etc. 36 to output as a monitor signal 37.

FIG. 7 is a block diagram of the smoothing circuit, and shows the binary signal 34 output from the binarizing circuit 21.

For each column line 13 shown in FIG. 4(B), shift registers 28, 3Q, 40 and line memories 41', 42 are provided.
and address counter 43. It is constructed by connecting several stages of blocks 45 consisting of AND output gates 44.

FIG. 8 is a block diagram of the white mask extraction circuit, showing the launches 461 to 46 and 47. which temporarily hold the smoothed image signal of the smoothing circuit shown in FIG. ~47n, line memories 481 to 48n and 491 to 49 that have a relatively small capacity or have a large number of bits and are vertically connected to each launch.
rL1 address counter 50 and or gate 51
1 to 51fi and Nantes gates 52°, 53, and 54, which determine whether or not the white level is continuous. Note that this white mask extraction circuit stores line memories 481 to 4Bn as fixed lines E.
If the line memories 491 to 49n are selected and used for the movable line F, the boundary between the white level zone and the black level zone, that is, the outline of one image, can be clearly distinguished. The circuit cooperates with a smoothing circuit 23 so that accurate binarized x-y coordinates are obtained.

FIG. 9 is a block diagram of the local memory circuit, in which the output signal 56 of the white mask extraction circuit and the synchronization signal 36' of the external block are input, and the column line 1 shown in FIG.
In order to set the X-axis and Y-axis limits of 3, the microcomputer usually converts the data from latches 57 and 58 that hold the data transferred via digital switches and the output signal level into data. The digital ratio ta60.61 is used to compare the output data from the white level counter 59, and the result of the comparison is outputted and receives a latch pulse, and the white/level counter 59L and ? It mainly consists of a local memory 62 that stores divided capacities in the X-axis and y-axis directions set in advance in the microcomputer.

Incidentally, as for the synchronizing signal generating circuit 22, the mixing circuit 26, and the monitor display circuit, conventionally known circuits may be applied, and their explanations in the embodiments are omitted.

As a result of the above, the pattern recognition system according to this embodiment can be applied to the upper dicing start point (E point) and the upper dicing end point (E point) on the semiconductor wafer.
0 points) in advance, and for each sprint image,
By detecting and calculating the position coordinates, it is possible to accurately determine the center m9 on the dicing schedule (11), the degree of bending in the be able to.

Although the above embodiment described the division into ~ semiconductor wafers, this generation 8LJ should not be limited to this.9- It can also be used, for example, when processing a sheet-like work according to an accurate set pattern. Can be done.

According to this invention, a light beam is irradiated to various points separated from each other in a pattern to be recognized, and the resulting sprint image is detected by position coordinates using a binarization circuit, a smoothing circuit, a white mask extraction circuit, a local memory circuit, etc. - Accurate pattern recognition is possible through arithmetic processing, resulting in extremely high feasibility and workability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a conventional pattern recognition device, FIG. 2 is a plan view of a semiconductor wafer, FIG. 3 is an enlarged schematic diagram of the small circle AK, and FIGS. The figures relate to the present invention; FIG. 4 is an enlarged schematic diagram showing (A) and υ) t/'i sprint images; FIG. 5 is a block diagram of a pattern recognition device according to an embodiment of the present invention; and FIG. is a block diagram of the binarization circuit, FIG. 7 is a block diagram of the smoothing circuit, FIG. 8 is a block diagram of the white mask extraction circuit, and FIG. 9 is a block diagram of the local memory circuit. . B...B point, 0...0 point, D...Sprint image, 20...-TV camera, 21...Binarization circuit, 23. ...
...Smoothing file F? , 24... White mask extraction circuit, 25... Local memory circuit. ll-

Claims (1)

[Claims] In a pattern recognition device that processes a video signal obtained by irradiating a light beam onto a pattern to be recognized and photographing it with a TV camera, the light beam is irradiated at various distant points on the pattern to be recognized, and each is input to the TV camera. A pattern recognition device characterized in that a synthesized split image is obtained and the size and shape of the splint image is determined by an image processing circuit that performs position coordinate detection and arithmetic processing.