JPH0466020B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an apparatus for correcting defects in a group of light-shielding patterns of the same shape that are regularly arranged in large numbers.
In particular, when a part or all of a pattern to be blocked has a defect that allows light to pass through, the present invention relates to an apparatus that can correct the defect without the need to accurately locate the correction site with the naked eye.

(Prior Art) Conventionally, photographic plates used in exposure processes such as corrosion processing of metal materials are those in which a light-shielding pattern is formed on a transparent substrate such as a transparent film or a glass plate in either positive or negative form. However, if a defect occurs that allows light to pass through without forming a light-shielding pattern in a part of the area that should be light-shielded, by additionally forming a light-shielding pattern on the defective area before use. The defects were being corrected. The usual method of repair is for the repairer to observe the light-blocking pattern under magnification, apply ink to the tip of a brush, and carefully fill in the defective area.

In addition, if the light-shielding pattern is made of a light-shielding metal film, the repair person uses a magnifying glass to observe the area under magnification using a video imaging device, and forms a mask or the like precisely over the defective area. A known method is to form a light-shielding film using a vapor deposition method or a coating method to correct the problem.

(Problem to be Solved by the Invention) However, not only in the case of the above-mentioned visual inspection and manual correction, but also in the method of correcting a light-shielding metal pattern using a mask, the position and shape of the defect to be corrected cannot be determined. Accurate identification is required with the naked eye through a magnifying glass or video image, which requires the skill of the corrector to make accurate corrections, and accurate corrections generally avoid inefficiency due to long hours of work. There were problems such as not having one. Moreover, in recent years, there has been an increasing need for precise patterns among the patterns that are subject to corrosion processing of metal materials, and along with this, the details of defect correction in photolithography have also become more precise, making it possible to identify precise positions with the naked eye. This is becoming increasingly difficult.

SUMMARY OF THE INVENTION Therefore, the present invention provides an apparatus that roughly identifies the defective area while observing a light-shielding pattern enlarged and displayed on a display device, thereby automatically measuring the exact position of the defect and also accurately correcting the defect. The purpose is to

(Means for Solving the Problem) By the way, when the light-shielding pattern of the photographic original plate consists of a regular repetition of a large number of isolated patterns of the same shape, as in the case of a shadow mask original plate for a color television receiver, Since a normal light-shielding pattern exists around the defect, the position and shape of the defective light-shielding pattern can be automatically calculated from the shape and position of this normal pattern based on the arrangement rule.

The present invention has been made based on such technical reasons, and in other words, the invention according to claim 1 is directed to a photograph in which a large number of light-shielding patterns of the same shape are regularly arranged on a light-transmitting substrate. A device for correcting light-transmitting defects existing in an original plate includes (a) a moving stage on which the photographic original is placed and moves in the X, Y, and Z directions; (b) an imaging device that photographs the defective area and its vicinity. (c) a display device that magnifies and displays an image taken by the imaging device; (d) a correction head capable of printing a pattern identical to the normal form of a single light-shielding pattern; (e) the imaging device described above. The shape of a group of normal light-shielding patterns in the vicinity of the above-mentioned defect photographed by the device, or the shape of a normal part of a light-shielding pattern with a partial defect, the normal form of a single light-shielding pattern, and the reference part of the above-mentioned correction head. (f) calculating means for calculating the representative position of the defective light-shielding pattern by comparing corresponding predetermined arrangement rules of representative positions; The present invention is characterized by comprising a correction means for aligning a representative position of the light-shielding pattern with a reference portion of the correction head and operating the correction head to form a normal-shaped light-shielding pattern.

(Operation) According to the invention as claimed in claim 1, first, a photographic original is placed on a moving stage, an appropriate part of the photographic original is enlarged and displayed using an imaging device and a display device, and while observing this display screen, , the movable stage is freely moved in each of the X, Y, and Z directions, the focal length is adjusted, and the defect site and its vicinity are displayed on the screen.

Next, the normal light-shielding pattern photographed by the imaging device is compared with the normal form of a single light-shielding pattern and the rules for the arrangement of representative positions, and the calculation device calculates the defective light-shielding pattern. Calculate representative positions. Here, the term "representative position" refers to the position of the light-shielding pattern that corresponds to the part that serves as a reference for the position of the correction head when making corrections using the correction head; for example, it has the same shape as the normal shape of the above-mentioned light-shielding pattern. Assuming that the central part of the correction head having a discharge portion of 1 is the reference part of this correction head, a representative position of the light-shielding pattern provided on the photographic original is selected at the center of this light-shielding pattern. Since a large number of light-shielding patterns are arranged, there are as many representative positions of a single light-shielding pattern as there are light-shielding patterns, and since the light-shielding patterns are arranged regularly, These representative positions are also arranged regularly. Since there is a normal light-shielding pattern around the defective light-shielding pattern, this normal light-shielding pattern is included in the image of the defective site and its vicinity taken by the imaging device. Therefore, the shape of the normal light-shielding pattern around the defective light-shielding pattern is photographed, and the typical position of the defective light-shielding pattern is automatically determined by a calculation device according to the above arrangement rule. It can be calculated.

Finally, the defect can be accurately corrected by aligning the reference portion of the correction head with the representative position of the defective light-shielding pattern thus calculated and specified and operating it.

(Example) Hereinafter, a case in which the present invention is applied to correction of a photographic original plate for a shadow mask will be described in detail with reference to the drawings.

As shown in enlarged views in FIGS. 1a and 1b, the shadow mask photographic original plate 5 has circular light-shielding patterns 2 of the same diameter on one side of a transparent substrate 1 in the form of a matrix with rows and columns in the diagonal direction. A defect (hereinafter referred to as a "chip") 3, which is composed of a large number of regularly arranged light-shielding patterns 2 and in which a part of one light-shielding pattern 2 transmits light, or a defect 3 in which one light-shielding pattern 2 completely disappears. defects (hereinafter referred to as "defects") 4 tend to exist.

These chips 3 and defects 4 can be detected relatively easily by visual inspection, etc., partly because the light-shielding patterns 2 are regularly arranged. For example, defects can be easily found by placing an inspection sheet made of a transparent film with checkerboard lines on the photographic original 5 and searching each square section with a magnifying glass. By such a visual inspection, a mark or the like is placed in advance at the approximate position of the defect existing in the photographic master plate 5 for shadow mask, and then the photographic master plate 5 for use in the shadow mask is subjected to the correction apparatus of the present invention.

Referring to FIG. 2, the correction device of the present invention will be described. The photographic original plate 5 whose approximate position of the defect has been found in advance is placed so that the defective part is directly under the magnifying lens 9 attached to the imaging device 8. The photographic original plate 5 is placed and fixed on the moving stage 6 with the film side facing up. Since the general position of the defect is known in advance using a landmark or the like, it is easy to magnify and capture the defect site and its vicinity. The moving stage 6 is equipped with three stage drive devices 7 so that it can move in the horizontal direction (X, Y direction) and vertical direction (Z direction), but in the illustrated embodiment, only one stage drive device 7 is shown. be. In addition, transmitted illumination 1 for 5 photographic originals
0. Install reflected lighting 11 so that both lighting systems can be used. The image magnified by the objective lens 9 is input to the imaging device 8 and displayed on the television display tube 15 via the binarization circuit 12.

The photographic original plate 5 is originally a binarized pattern that can be clearly distinguished into light-transmitting areas and light-blocking areas, but the imaging device 8
The output is an analog signal with some density gradation caused by light dirt and optical system shading. In the present invention, in order to facilitate subsequent image processing, 2
digitize and apply digital image processing.

By moving the moving stage 6 appropriately in the X, Y, and Z directions while observing this displayed image with the naked eye, the chip 3 or the chip 4 and its surroundings can be accurately focused approximately at the center of the screen of the television display tube 15. A light-shielding pattern 2 can be displayed.

The signal from the binarization circuit 12 is also input to the central processing unit (hereinafter simply referred to as CPU) 14, and compared with the shape and arrangement rules of a normal circular light-shielding pattern, the chip 3 or 4 is detected. Measure and calculate representative positions. In this case, the representative position corresponds to the center position of the light-shielding pattern that is the source of the chipping 3 or the chipping 4. The representative position of the chip 3 can also be found by measuring the remaining normal shape of the isolated pattern where the chip 3 exists and comparing it with the normal shape. It may be calculated based on the measurement of the mutual positional relationship with the light shielding pattern. The representative position of the defect calculated within the screen can be redefined in an appropriate coordinate system by taking into account the position on the moving stage 6.

To explain this point using the screen images 3a and 3b, a concrete example is shown.
, and if the defect is so slight that the perfect shape of the light-shielding pattern 2 can be fully predicted, move the moving stage 6 slightly to move the cursor placed at the center of the screen of the television display tube 15. Scale 18
Move chip 3 to the center of the area surrounded by. When the chip 3 is moved to the center, input this position information to the CPU 14 and compare it with the normal shape described above. Based on the position of the moving stage 6,
It is possible to calculate a representative position of a defective light-shielding pattern using an appropriate coordinate system.

More accurate calculation of the representative position of the light-shielding pattern having the notch 3 can also be performed by the following method.

In other words, if the normal shape of the light-shielding pattern is circular as shown in this example, any three points among the normal edges of chip 3 are sequentially moved to the center point of the cursor area, and the position information of each point is obtained. Input to CPU14. Since the normal shape of the light-shielding pattern is circular, the CPU 14 calculates the coordinates of the center point of the circle based on the position of the moving stage 6, and the thus calculated coordinates of the center point can be used as the representative position.

When the defect is a defect 4, or even if it is a defect 3, the extent of the defect is so large that it is impossible to predict the complete shape of the light-shielding pattern, the method shown in FIG. 3b is versatile and convenient. . In other words, the same is true for any type of defect, but in the case of a defect, a defect is the absence of a light-shielding pattern where it should exist, so in order to identify the representative position of the defect, it is necessary to The relationship with a normal light-shielding pattern is used. In the example shown in Figure 3b, the light-shielding patterns are circular with equal length from the center point (representative position), and are regularly arranged in a matrix with rows and columns in the diagonal direction, so If the midpoint C of the line segment defined by the closest points A and B of the adjacent light-shielding patterns is determined, it is the center point (representative position) of the missing circular light-shielding pattern. In addition, the line segment DE and the line segment formed by the closest points D and E of adjacent light-shielding patterns at different angles.
A representative position can also be calculated by finding the intersection of AB. These methods differ depending on how the light-shielding patterns are arranged, but in any case, as long as the light-shielding patterns are the same and the arrangement is regular, the CPU 14 can automatically calculate the representative position. It is a matter of nature.

Next, the coordinate values determined by this method are displayed on the numerical display 16 as appropriate. On the other hand, the correction head 13
is placed in advance at a certain distance from the imaging device 8, and by operating the moving stage 6 and aligning the representative position of the defect with the position corresponding to the correction head 13, the representative position of the defect is determined. can be set directly below the correction head 13. Thereafter, the correction head 13 is operated to form a light-shielding film in the same shape as the isolated pattern, and then the light-shielding film is dried and arced to complete the repair of the defect. The correction head 13 used here has a correction liquid discharge part at the tip of the head, and the shape of the discharge part is the same as that of a single isolated light-shielding pattern. A correction head is set directly above a representative defect, and after lowering the correction head until it reaches the surface of the photographic original plate 5, a correction liquid is discharged from the discharge portion. As the correction fluid, a mixture of a thermosetting resin or an ultraviolet curable resin with a dye having a light blocking property is used. The light-shielding film formed from the curable resin mixed with this dye can be easily removed and retouched before drying and solidifying, and has good adhesion after drying and solidifying, so it is usually This is more desirable than a light-shielding film made of water-soluble black ink or ink. It is important for the accuracy of the correction position that the correction head 13 be fixed to its support with high precision and stability. , it is generally difficult to maintain high accuracy. Therefore, in practice,
Adjust the position of the correction head as necessary on keyboard 1.
7 to the CPU 14 so that the corrected coordinate values can be displayed on the numerical display 16.

(Effects of the Invention) According to the invention described in claim 1, it is possible to automatically calculate the representative position of the defective light-shielding pattern by the calculation device, and to detect the defect based on the calculated representative position. Since it is possible to accurately correct the correction position, there is no need to accurately specify the correction position with the naked eye, and even though there is an increasing need for precise patterns among patterns that are subject to corrosion processing of metal materials, efficiency is high. This has the effect of allowing targeted and accurate correction.

[Brief explanation of drawings]

Figures 1a and b are partially enlarged views showing examples of defects in photographic original plates, Figure 2 is a schematic explanatory view showing an embodiment of the defect correction device according to the present invention, and Figures 3a and b are representative positions of defects. FIG. 2 is an explanatory diagram for explaining a method for identifying a 1... Translucent substrate, 2... Light blocking pattern, 3
...Chips, 4...Missing, 5...Original photo, 6...
Moving stage, 7... Stage drive device, 8...
Imaging device, 9... Magnifying lens, 10... Transmitted illumination, 11... Reflected illumination, 12... Binarization circuit, 1
3... head for correction, 14... central processing unit (CPU), 15... television display tube, 16... numerical display, 17... keyboard.

Claims (1)

[Scope of Claims] 1. In an apparatus for correcting a light-transmitting defect existing in a photographic original plate, which is formed by regularly arranging a large number of light-shielding patterns of the same shape on a light-transmitting substrate, A moving stage on which the defective part is placed and moved in the X, Y, and Z directions; (b) An imaging device that photographs the defective area and its vicinity; (c) A display device that enlarges and displays the image taken by the imaging device. (d) A correction head capable of printing a pattern identical to the normal form of a single light-shielding pattern; (e) A defect in a normal light-shielding pattern group or part near the defect photographed by the imaging device. The defect is determined by comparing the shape of a normal part of a certain light-shielding pattern with the normal shape of a single light-shielding pattern and the rule of arrangement of representative positions predetermined corresponding to the reference part of the correction head. (f) calculating means for calculating a representative position of a light-shielding pattern with a defect; A photolithography defect correction device comprising: a correction means that is operated to form a normal light-shielding pattern.