JP2002257749A - Inspection device, inspection method, and method of manufacturing color filter using thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely discriminate a defect to be detected from a defect not required to be detected, so as to provide an inspection device of high precision, and to provide an inspection method and a color filter manufacturing method using the inspection device. SOLUTION: This inspection device for inspecting an appearance of a product has a function for discriminating the defect for which a detection signal is to be detected from the defect for which the detection siganl is not rerquired to be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an inspection apparatus and an inspection method, and more particularly to a method of manufacturing a color filter.

[0002]

2. Description of the Related Art Devices for detecting defects such as foreign matter, in particular,
At present, the following types of inspection devices detect defects such as foreign substances on a color filter substrate consisting of a black matrix (light shielding layer) formed on a transparent substrate and transparent colored layers of red, blue and green. It has become mainstream.
That is, the inspection substrate is irradiated with inspection illumination from the light source device, and the light reflected by the inspection substrate is received by the photoelectric conversion element. Next, the light received by the photoelectric conversion element is converted into an electric signal, and the electric signal is processed to detect a defect.

[0003] In such a defect inspection apparatus, the prior art has been developed with an emphasis on increasing the defect detection limit level so that even smaller defects can be detected. Defects and adhered foreign substances that do not need to be detected are detected, and determination is made using the same threshold, so that excessive detection has occurred. For this reason, it is necessary to correct the defect detected by the inspection device by a visual inspection of a person, which makes it difficult to quickly and accurately deal with the defect.

[0004]

An object of the present invention is to separate the defects to be detected from the defects which need not be detected without impairing the original detection capability of the inspection device. An inspection apparatus that performs the inspection and determines the acceptability of the inspected object based on the detection result of only the defect to be detected,
It is to provide an inspection method.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an inspection apparatus for detecting a defect of an object to be inspected by processing a detection signal obtained by inspecting the object to be inspected. An inspection apparatus characterized in that it has a function of separating defects that need not be performed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the inspection apparatus of the present invention will be described below.

Although the hardware configuration of the present invention is not particularly limited, a specific example is the same as in the prior art, which has a light source device for irradiating the object to be inspected with the inspection illumination. The illumination has a photoelectric conversion element for receiving light reflected by the object to be inspected and converting the light into an electric signal,
There is an example having a signal processing device for processing the electric signal. Hereinafter, an embodiment of the present invention will be described by taking this optical system as an example. Here, as the photoelectric conversion element, it is preferable to use a CCD line sensor which is simpler in signal processing and most commonly used. Also, as the configuration of the optical system, to reduce equipment costs,
In addition, it is preferable that the optical system be composed of a pair of optical systems for ease of management. The optical system is of a reflection type, and the characteristic difference between the defect signal generated when detecting a defect to be detected and the disturbance signal generated when detecting a defect that is not necessary to be detected tends to be noticeable. Illumination systems are preferred. Defects that do not need to be detected are, for example, those that are removed in a later process such as adhered foreign substances and become non-defective products, minute projections that are smaller than product standards, and polished using a polishing tape or a polishing pad to become non-defective products. Among the detected objects, such as protrusions and noise generated during signal processing, the detected objects cannot be used as a basis for determining a defective product to be inspected. As the light source device for the inspection light source, a halogen lamp is preferably used.
A xenon lamp, a fluorescent lamp, a laser, or the like may be used.

[0008] Regarding the signal processing of the inspection apparatus of the present invention,
Up to the point where the reflected light from the object to be inspected is converted into an electric signal, the same as in the related art, but as a result of signal processing of the electric signal, a defect to be detected and a defect not to be detected are determined based on signal characteristics. Is determined. Utilizing the information of the defect that does not need to be detected, the inspection judgment can be corrected to improve the accuracy of the inspection judgment. The following is a description of preferred examples.

First, a defect to be detected and a defect that does not need to be detected are in the same region (for example, a coordinate position on a substrate plane,
In the following, description will be given of an example of coordinates). As the unifying method, for example, if a defect to be detected and a defect that does not need to be detected are detected at the same coordinates, the defect to be detected is determined to be noise caused by the influence of the defect that does not need to be detected. Then, there is a method of ignoring the defect to be detected. Of course, even in the case of a substrate on which such a detection has been made, if a defect to be detected is detected at another coordinate, and a defect that does not need to be detected is not found from that coordinate, this detection is performed. The defect to be detected is not ignored, and therefore, it is determined that the substrate has a defect to be detected that is not ignored. Even when there is no defect to be detected, it is preferable to detect a defect that does not need to be detected. This is because the collected information on the defects that need not be detected is useful for knowing abnormalities in the manufacturing process such as a decrease in the cleanliness of the manufacturing process. When the quality of the object to be inspected is determined, only the detection result of the defect to be detected which has not been ignored is used. At the time of signal processing, a method of distinguishing between a detection signal of a defect to be detected and a detection signal of a defect that does not need to be detected can be selected according to the form of each signal.
Although methods such as pattern matching can be used,
In order to simplify the signal processing, it is preferable to set two thresholds, and to discriminate between a defect to be detected and a defect that does not need to be detected depending on which threshold is detected.

The same coordinates (or parts) include not only completely identical but also substantially identical neighborhoods. The neighborhood is not necessarily unconditional depending on the size and type of the device substrate, etc., but if it is roughly indicated, it may be 0.02% to 1.00% of the size of the device substrate.
% (Preferably 0.1% to 0.3%). When the value is below the lower limit of the numerical range, the automatic inspection means has, it is not possible to completely absorb the coordinate variation caused by machine accuracy, and it is not preferable to determine the same defect as another defect. This is because different defects existing in the place are determined to be the same defect, which is not preferable. When the size of the substrate is different in the vertical and horizontal directions like a rectangle, the square root of the area of the substrate is defined as the size of the substrate.

The inspection apparatus of the present invention is useful for the purpose of automatically inspecting for defects on the order of microns, and is preferably used for inspection of substrates for flat panel displays which require high precision. More preferably, it is used for filter inspection.

[0012]

The details of the preferred embodiment of the present invention are shown below, but do not limit the effectiveness of the present invention. In addition, even if a defect to be detected is detected, a case in which a defect that is not required to be detected at the same coordinates is detected, and as a result, a case where it is determined that the defect is not a detection target is hereinafter referred to as an AB case. . That is, in FIG. 2, it is determined that there is a defect in the defect detection processing 5 (Y).
This is the case (Y) after which it is determined that there is a defect in the disturbance detection processing 6 near the defect.

Embodiment 1 (1) Hardware Configuration As a hardware configuration, an inspection apparatus (CMF-510 manufactured by Takano Corporation) for a coaxial incident-light optical system as shown in FIG.
0) was used. In addition, the light source device is MHOREX MH
Using a F-100LR, a 4096 pixel CCD line sensor was used as a photoelectric conversion element. In FIG. 1, the distance from the color filter substrate 1 to the CCD line sensor 2 is 1
96 mm, the distance from the light source 3 to the color filter substrate 1 is 105 mm, and the light radiated horizontally from the light source 3 to the color filter substrate 1 is bent 90 ° downward by the half mirror 4 at a position 20 mm from the light source 3 to form a color filter. The light was perpendicularly incident on the substrate. A distance of 85 mm was set so that the optical axes of the incident light and the reflected light overlapped. (2) Software Configuration The software configuration will be described with reference to the flowchart shown in FIG. Processing equipment is Takano MF-
5500 was used. First, the reflected light from the color filter substrate 1 is converted into an electric signal by the CCD line sensor 2. Next, a defect detection process 5 shown in FIG. 2 is performed. FIG. 3 shows an example of the signal obtained at this time. The portion detected by the threshold value A for determining the defect to be detected is a portion detected by the threshold value B for determining a defect which does not need to be detected near the same coordinates as shown in FIG. Processing 6 is performed to determine whether there is any. If there is no part detected by the threshold value B in the processing of 6, the part is determined to be a defect to be detected. If there is a portion detected with the threshold B, it is determined that the defect does not need to be detected. Further, it is determined whether there is a part to be detected at the threshold B shown in FIG.
If there is a portion to be detected by the threshold B, it is determined that the defect does not need to be detected, and if there is no portion to be detected by the threshold B, a process 7 of determining a normal portion is performed. This series of processing is performed for the entire inspection area arbitrarily set for the object to be inspected, and after the inspection of the entire inspection area is completed, it is determined whether there is a defect to be detected as shown in FIG. Then, the process 8 for determining the quality of the inspected object is performed. The threshold A and the threshold B can be arbitrarily set, respectively, and in this example and the comparative example, the threshold A was 170 and the threshold B was 30. (3) Confirmation of Effect The pinhole inspection of the color filter was actually performed using the inspection apparatus having the configuration described in (1) and (2). The color filter used for the verification was obtained by forming a resin black matrix on a non-alkali glass substrate, forming each of the RGB transparent coloring layers and the O / C protective film layer thereon, and then forming an ITO thin film. The automatic inspection device of the present invention was installed and operated in this color filter manufacturing process. The detection signal of the device is decomposed into 256 gradations,
The binarization level is set to 170, and those exceeding this are set as defects to be detected, and the binarization level of the threshold B is set to 50, and those below this are extracted as unnecessary to detect. According to the inspection apparatus of the present invention, 90% (of which 35% are AB cases) were judged as non-defective. The remaining 10% were defects that should be detected. It has been confirmed that the inspection apparatus of the present invention makes it almost impossible to detect a case that is erroneously determined to be detected due to a defect that does not need to be detected, such as dust or foreign matter.

COMPARATIVE EXAMPLE 1 When a board similar to the test (3) was inspected using a conventional inspection apparatus, 60% of non-defective products were inspected, and 35% of the remaining 40% were defects that did not need to be detected. there were.

Embodiment 2 An apparatus having the configuration described in (1) and (2) of Embodiment 1
The effect was also verified for the ITO pinhole inspection of the color filter with pillars. The color filter with pillars is formed by forming a resin black matrix on a non-alkali glass substrate, forming RBG transparent colored layers and each laminated pillar on the matrix at a pitch of one for every three pixels, and protecting O / C. A film layer is formed, an ITO film is formed, and a color filter formed in the same manner as the color filter used in (3) of the first embodiment is acrylic-coated at a pitch of one for every three pixels. A resin having a column having a height of 5 μm formed using a resin was used. According to the inspection apparatus of the present invention, 80% (of which 40%
(A-B case) was judged as a non-defective product. The remaining 20% were defects that should be detected. It has been confirmed that the inspection apparatus of the present invention makes it almost impossible to detect a case that is erroneously determined to be detected due to a defect that does not need to be detected, such as dust or foreign matter.

COMPARATIVE EXAMPLE 2 When a board similar to the test of the above (1) was inspected by a conventional inspection apparatus, 50% of non-defective products were used, and 30% of the remaining 50% were defects that did not need to be detected. there were.

[0017]

According to the inspection apparatus of the present invention, excessive detection can be suppressed and a defect to be detected with higher accuracy can be detected. In addition, by using the inspection apparatus and the inspection method of the present invention, it is possible to more accurately determine the quality of the inspected object based on the inspection result of the defect to be detected, thereby improving the yield in color filter manufacturing and enabling early process feedback. Becomes

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an optical system of an inspection apparatus as an example of an embodiment of the inspection apparatus of the present invention.

FIG. 2 is a data processing flowchart of an inspection apparatus as an example of an embodiment of the inspection apparatus of the present invention.

FIG. 3 is an example of a detection signal when an inspection apparatus according to the present invention detects an ITO pinhole and an attached foreign matter.

[Explanation of symbols]

 1: Color filter substrate 2: CCD line sensor 3: Light source 4: Half mirror 5: Defect detection process 6: Disturbance detection process near defect 7: Disturbance detection process 8: Color filter substrate determination process

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G051 AA73 AB04 AB07 BB03 CA03 CB01 EA11 EA12 EB01 EB05 2G086 EE05 EE10 2H048 BA02 BA11 BB02 BB14 BB42 2H088 FA11 HA12 MA20 2H091 FA02Y FC30 LA30

Claims (10)

[The claims] In an inspection apparatus for processing a detection signal obtained by inspecting an object to be inspected to detect a defect of the object to be inspected, the inspection signal is classified into a defect to be detected and a defect not to be detected. An inspection apparatus characterized by having a function to perform. 2. The inspection apparatus according to claim 1, wherein the inspection signal includes a light source device and a photoelectric conversion element, and the detection signal irradiates the inspection object with inspection light from the light source device, and reflects the light reflected by the inspection object. 2. The inspection apparatus according to claim 1, wherein the detection signal is a detection signal obtained by receiving light by the photoelectric conversion element and performing photoelectric conversion. 3. The quality of an object to be inspected is determined based on the detection result of the defect to be detected.
Or the inspection device according to 2. 4. The inspection apparatus according to claim 1, wherein the inspection apparatus has a function of ignoring a defect to be detected detected in a substantially same part as a part in which the unnecessary defect is detected. 5. The apparatus according to claim 2, wherein at least a part of an optical path from the light source device to the object to be inspected and an optical path from the object to be inspected to the photoelectric conversion element overlap. Inspection equipment. 6. A method according to claim 1, wherein at least two threshold values are set, and a defect to be detected or a defect that does not need to be detected is discriminated according to whether any of the threshold values is detected. Inspection device as described. 7. The inspection apparatus according to claim 1, wherein the object to be inspected is a substrate for a flat panel display. 8. The inspection apparatus according to claim 1, wherein the object to be inspected is a liquid crystal color filter. 9. A color filter inspection method using the inspection device according to claim 7. Description: 10. A method for manufacturing a color filter using the inspection method according to claim 9.