JP2010175433A - In-line method of inspecting transparent conductive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of inspecting a transparent electrode which can prevent serious troubles requiring to reexamine all of color filter substrates between sampling inspection periods and be free from decrease of productivity even when all of color filter substrates are reexamined. <P>SOLUTION: In the in-line method of inspecting a transparent conductive film, existence or nonexistence of the transparent conductive film on the color filter is determined by forming the color filter and the transparent conductive film on a transparent substrate, passing the substrate through between a UV light source and a UV-ray sensor on a convey line, and measuring a transmittance of a portion where the transparent substrate and the transparent conductive film are laminated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a color filter substrate for a liquid crystal display device, and more particularly to an inspection method for in-line inspection for the presence or absence of a transparent conductive film formed on a color filter.

  In a color filter substrate used for a color liquid crystal display device, a transparent conductive film (hereinafter referred to as an ITO film) for applying a voltage for driving a liquid crystal is usually formed on the color filter by sputtering after forming the color filter. Form.

  In the color filter manufacturing process, it is necessary to reliably manage whether the ITO film is properly formed. However, whether or not the ITO film is applied to a desired portion on the color filter and the film thickness is within a desired range on the color filter is determined for all the manufactured color filter substrates, particularly in a large area. Inspecting and confirming the color filter substrate is accompanied by a significant decrease in productivity, and it is considered unnecessary in practice because of the stability of the ITO film manufacturing process.

  Therefore, in general, a color filter substrate is sampled at an appropriate timing, and if an abnormality is found, a detailed inspection is performed to identify the cause of the abnormality and restore the original state (patent) Reference 1).

JP 2003-262666 A

In the present invention, if an abnormality is detected in the sampling inspection only by the sampling inspection after the ITO film is formed, a precise re-inspection is performed on a considerable number of color filter substrates manufactured before and after the sampling inspection. The need to come out. In this case, in order to maintain productivity, it is necessary to prepare a considerable number of ITO inspection apparatuses that are generally low in the number of processed sheets per unit time and very expensive. Or, in order to maintain productivity, it may occur that the inspection points of the ITO film are narrowed down.
In view of this, the present invention can prevent the occurrence of a large trouble that necessitates a total inspection of the color filter substrates manufactured in a certain time span including the sampling inspection time, and inspects the total number of color filter substrates. In addition, an object of the present invention is to provide an ITO film inspection method that does not reduce productivity.

  In order to achieve the above object, according to the first aspect of the present invention, after a color filter and a transparent conductive film are formed on a transparent substrate, the substrate passes between an ultraviolet light source and an ultraviolet sensor installed on a transport line. And determining the presence or absence of the transparent conductive film on the color filter by measuring the transmittance of the laminated portion of the transparent substrate and the transparent conductive film. .

  The invention according to claim 2 is a method for inspecting an in-line transparent conductive film according to claim 1, wherein the transmittance of the wavelength is measured using a light source having high luminance near 450 nm and near 600 nm. It is what.

According to the present invention, the transmittance of the laminated portion of the transparent substrate and the transparent electrode at the inner connecting portion other than the portion effective as the color filter multi-faced with the peripheral portion of the color filter substrate is measured by a simple method of transmittance measurement. Multiple points can be measured.
Therefore, it is possible to obtain reliable information as to whether or not the transparent electrode is formed on the color filter in the same manner.
In addition, transmittance measurement has high measurement reliability, can be measured in a short time, and the device configuration is simple. Therefore, it does not spend much cost for inspection, and even if it is introduced into the color filter manufacturing process by an inline method, the color filter substrate There is no reduction in productivity.

The top view explaining an example of arrangement | positioning of a color filter board | substrate, a light emission light source, and an ultraviolet sensor. The figure explaining an example of the film thickness of a transparent electrode, and the wavelength dependence of the transmittance | permeability.

As shown in FIG. 1, the light source 21, 22, 23 and the optical sensor 3 in the ultraviolet to visible region for measuring the transmittance convey the color filter substrate 4 on which the transparent electrode has been formed to the next process. It is desirable to install it at an appropriate position of the substrate transport unit 1, particularly at a position where the color filter substrate 4 is temporarily stopped.
The light emitting light sources 21, 22, 23 and the light sensor 3 are installed on the line in the direction perpendicular to the conveying direction with the color filter substrate 4 interposed therebetween, and are selected according to the imposition position, the number of necessary monitoring points, and the like. It is desirable to use it. It is preferable to install a plurality of light emitting light sources such as a light source 21 that covers a wide ultraviolet region, a visible light source 22 having a wavelength of 450 nm, and a visible light source 23 having a wavelength of 600 nm. Since the reliability of film thickness measurement may be lacking with only a single wavelength, it is preferable to calculate the film thickness using at least two or more wavelengths in combination. The measurement position is preferably other than the part where the color filter is formed.
In FIG. 1, the light sensor is installed on the back side of the color filter substrate in correspondence with the light source, and is shown by a broken broken line for easy understanding.

FIG. 2 is a diagram for explaining an example of the wavelength dependence of the film thickness and transmittance of the transparent electrode.
For example, when monitoring whether the desired film thickness of the transparent electrode is around 1300 mm, is the transmittance in the range of 95% to 97% at a wavelength of 450 nm, and whether the transmittance is in the range of 91% to 93% at 600 nm? Can be judged by no. When monitoring whether the desired film thickness is in the vicinity of 1700 mm, it is determined whether the transmittance is in the range of 84% to 86% at a wavelength of 450 nm, and whether the transmittance is in the range of 96% to 98% at 600 nm. To do. Since the range of transmittance to be obtained depends on the tolerance of the film quality or film thickness of the transparent electrode, the wavelength dependence of the film thickness and transmittance of the transparent electrode shown in FIG. It is desirable to calculate in advance.

  The UV transmittance of 300 nm or less is sufficiently low for transparent electrodes compared to transparent substrates such as glass. Therefore, if a transparent substrate is used as a reference, highly reliable information on the presence or absence of the transparent electrode can be obtained. . Therefore, if there is only the presence or absence of a transparent electrode, it is possible to quickly check only by the transmittance of ultraviolet rays.

1. Substrate transport unit 2, light emission source 21, ultraviolet ray 22, 450 nm
23, 600 nm
3. Optical sensor 4, color filter substrate

Claims (2)

  After forming the color filter and the transparent conductive film on the transparent substrate, the substrate is passed between the ultraviolet light source and the ultraviolet sensor installed on the transport line, and the transmittance of the laminated portion of the transparent substrate and the transparent conductive film is determined. An in-line transparent conductive film inspection method, wherein the presence or absence of a transparent conductive film on the color filter is determined by measurement.   The in-line transparent conductive film inspection method according to claim 1, wherein the transmittance of the wavelength is measured using a light source having high luminance near 450 nm and near 600 nm.

Images