JPS60117380A - Pattern processing method - Google Patents

Abstract

PURPOSE:To remove unevenness in the vicinity of the boundary of patterns only without removing minute defects by removing only empty areas in the vicinity of the boundary of the patterns in the preprocessing of patterns at the time of inspection by detecting the patterns optically. CONSTITUTION:Each part represented by A, B, C, and D at the left side of the figure shows sensors respectively and sensors B and D shown by squares with black dots correspond to black (1) and each of the sensors C corresponds to white (0). The A, B, C, and D at the right side show outputs of preprocessing of patterns and are connected with the sensors by means of an inverter 11, AND gate 12, and OR gate 13. When black appears at the marginal part of a pattern and unevenness occurs at this part, the A at the outside of the B is white and the B is connected with the D by black, and therefore, unevenness in the vicinity of the boundary of patterns disappears by preprocessing. When the disconnected part of the line is preprocessed, the A is not white and the B is connected by black with the D. Therefore, the disconnected part is left as white, namely as a disconnected part.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a pattern processing method, and particularly to a pattern processing method in an apparatus for optically detecting and inspecting a pattern.

(2) Background of the Technology For example, devices for inspecting patterns of circuits formed on printed circuit boards used in microcomputers, etc., and in particular, devices for automatically inspecting patterns, have been developed. To automatically inspect a pattern, first read the pattern optically, convert the result into an electrical signal, and observe this electrical signal in another electrical circuit (1) to check for defects. . At that time, preprocessing is performed prior to the inspection. The present invention relates to a method for this pretreatment.

(3) Prior Art and Problems In pattern inspection apparatuses, preprocessing is always performed on detected patterns in order to prevent malfunctions of defect detection circuits. Since the first read pattern itself contains noise and has uneven edges, it is difficult to inspect the read pattern as it is, so preprocessing is performed to eliminate noise and unevenness.

The pattern is visually represented by light and white, with black appearing as a thin and short bar, and black and white electrically corresponding to "1" and "0".Especially near the boundaries of the pattern (also called edges). Since uneven parts are likely to occur in the pattern, it is desirable to eliminate the uneven parts, because otherwise the pattern will be detected as having defects.

One pattern is shown in FIG. The illustrated pattern is composed of the above-mentioned black bars and white (2), but the figure schematically shows a sandy background instead of the black bars. Although some of the unevenness on the edge is shown exaggerated on edge 1, similar unevenness also exists on other edges. In the pattern shown in Figure 1, the unevenness on edge 1 appears as a defect despite the absence of a defect, but the areas indicated by 2 and 3 in the figure are actually poor pattern spacing and disconnections. Defects exist.

When the pattern shown in Fig. 1 is preprocessed according to the prior art, the second
The pattern shown in the figure is obtained. Although it is good that the unevenness of the edge 1 is eliminated, the patterns are connected in areas where the pattern spacing is defective, and the disconnected i portions are also connected. This preprocessing removes minute defects, but even if the pattern shown in FIG. 2 is inspected, accurate detection will not be possible.

The above phenomenon is caused by the following pretreatment in the conventional method. Referring to FIG. 3, A,
Each part indicated by B and C represents a sensor, and the sensors A and B with sandy background correspond to (3) and black (1), and each of the sensors C corresponds to white (0). In the conventional method, when A=B=1, C-
1, and preprocessed to make everything black (1) as shown in FIG. 4, and this operation was performed in four directions.

As a result, not only the uneven edges were removed as described in 7 above, but other minute defects were also removed.

(41) Purpose of the Invention In view of the above-mentioned conventional problems, an object of the present invention is to provide a pattern preprocessing method with high inspection reliability in an apparatus that optically detects and inspects a pattern.

(5) Structure and object of the invention According to the present invention, pattern preprocessing when optically detecting and inspecting a pattern is performed by removing only the air area near the boundary of the pattern. This is achieved by providing a pattern processing method that

(6) Examples of the invention Embodiments of the present invention will be explained in detail below with reference to the drawings.

(4) The inventor of the present invention discovered that if the uneven edges of a pattern are left as they are, even if the pattern is good, it may be judged as defective during inspection. Although only the irregularities are removed, we recognize that other defects other than the edges must be left as they are, even if they are minute defects, and we consider the principles shown in Figures 5 and 6. Ta. That is, in FIG. 5, sensors A and C each represent white (0), and sensors B and D represent black (1). In the figure, black is represented with a sandy background. 0, and if B=D=0, then C=].The result is shown in Figure 6,
In the present invention, such sensors are provided in eight directions.

FIG. 7 shows a circuit for realizing the above operation,
In the figure, 11 is an inverter, 12 is an AND gate,
13 indicates an OR gate, respectively.

To explain the above operation with reference to FIG. 8, taking the area near the pattern boundary as an example, a black mark 4 appears outside the edge 1, which is the ethos of the pattern, and an empty (5') area appears at the edge. In other words, let's say that unevenness has occurred in this area. Applying Figure 5 to this, A outside B is white, and as described above, B to D are connected in black as in Figure 6, and the unevenness near the pattern boundary disappears. .

Next, the disconnected portion 3' will be explained with reference to FIG.

If we apply Fig. 5 to the broken line, since A is not white, there will be no connection from B to D in black, and the broken line will remain white, that is, the broken line itself.

The result of preprocessing the pattern shown in FIG. 1 in this way is shown in FIG. 10, and while the unevenness near the pattern boundary has disappeared, the pattern spacing defects and wire breakage have been maintained as they are and can be inspected. That will happen.

Note that even if the logical 1 and 0 of the above-mentioned embodiments are replaced, the small pattern removal process is possible, so the range of application of the present invention is not limited to the above-mentioned case.

(7) Effects of the Invention As explained in Group i above, according to the present invention, only the irregularities near the pattern boundaries can be removed without removing minute (6) defects, thereby improving the reliability of pattern inspection. - It is very effective for humans.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a pattern, FIG. 2 is a diagram showing the result of preprocessing the pattern in FIG. 1 by a conventional method, FIGS. 3 and 4 are diagrams showing the principle of conventional pattern preprocessing, 5 and 6 are diagrams showing the principle of pattern preprocessing of the present invention, and FIG.
Figure 8 shows a circuit for implementing the method of the invention.
9 and 9 are diagrams showing an embodiment of the method of the present invention, and FIG. 10 is a diagram showing the result of preprocessing the pattern of FIG. 1 according to the present invention. 1-Edge area (near the boundary), 2-Poor pattern spacing area,
3- Pattern disconnection part, 4- Black pattern, 11- Inverter, 12- AND gate, 13- OR gate (7)

Claims (1)

[Claims] A pattern processing method characterized in that pattern preprocessing when optically detecting and inspecting a pattern removes only the air space near the boundary of the pattern.