JP2003228074A - Color filter with spacer column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter with a spacer column, in which the column never peels off from a transparent conductive film in a cleaning process of a panel assembling stage of a liquid crystal display even when the spacer column is of about 8×8 μm size and is circular and to provide a manufacturing method. <P>SOLUTION: The spacer column is formed on the transparent conductive film 4 of ≥1.76 nm in center line mean roughness (Ra). The transparent conductive film is formed on color filter pixels 3 which have their surfaces polished almost to 1.7 nm center line mean roughness (Ra). The color filter pixels are polished almost to 1.7 nm center line mean roughness (Ra), the transparent conductive film of ≥1.76 nm in center line mean roughness (Ra) is formed, and the spacer column is formed on the transparent conductive film. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used in a liquid crystal display device, and more particularly to a color filter provided with spacer columns having a spacer function.

[0002]

2. Description of the Related Art Instead of a bead spacer used for forming a gap between substrates of a liquid crystal display device, a color filter with spacer columns having a protrusion having a spacer function has been put into practical use. The spacer pillars formed on the color filter are, for example, adhered to the transparent conductive film on the transparent conductive film of the color filter in which the black matrix, the color filter pixels, and the transparent conductive film are sequentially formed on the glass substrate. It is formed by photolithography using a photosensitive resin having good properties.

The size and shape of the spacer column is such that the horizontal cross section is a rectangle with rounded corners of about 13 × 19 μm, or a rhombus with rounded corners of a diagonal length (20 × 20 μm) to (15 × 15 μm). Was often used. 2. Description of the Related Art In recent years, with the increase in definition and quality of liquid crystal display devices, there has been a demand for finer spacer columns, and their size and shape are 12 ×.
The horizontal cross section of about 12 μm has changed to a circle and the horizontal cross section of about 8 × 8 μm.

The size and shape of this spacer column is approximately 1
When the size of the circular filter is about 2 × 12 μm or more, there is no problem with the spacer pillar color filter, that is, the spacer pillar is not peeled off from the transparent conductive film and is manufactured as a liquid crystal display device through a panel assembly process of the liquid crystal display device. To be done. However, the size and shape of the spacer column is approximately 8
If the size is smaller than a circle of about 8 μm, a part of the spacer pillar may be peeled off from the transparent conductive film in the cleaning process after the spacer pillar is formed, the inspection process, and the cleaning process in the panel assembly process of the liquid crystal display device. There is.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in a color filter with spacer columns, the size and shape of the spacer column is more than a circle of about 8 × 8 μm. Provided with a spacer pillar color filter that does not peel off the spacer pillar from the transparent conductive film in the cleaning process after the spacer pillar is formed, the inspection process, and the cleaning process in the panel assembly process of the liquid crystal display device even if the size is small. The task is to do so. Another object of the present invention is to provide a method for manufacturing the above color filter with spacer columns.

[0006]

The present invention is a color filter with a spacer pillar in which at least a color filter pixel, a transparent conductive film, and a spacer pillar are sequentially formed on a glass substrate, and the spacer pillar has a center line. Average roughness (Ra)
A color filter with a spacer pillar, which is formed on a transparent conductive film having a thickness of 1.76 nm or more.

According to the present invention, in the color filter with spacer pillars according to the present invention, the transparent conductive film is formed on a color filter pixel whose surface is polished to a center line average roughness (Ra) of about 1.7 nm. A color filter with a spacer pillar, which is a transparent conductive film.

The present invention also provides a method of manufacturing a color filter with spacer pillars, wherein 1) at least a color filter pixel is formed on a glass substrate, and the surface of the color filter pixel has a center line average roughness (Ra) of 1 2) Center line average roughness (Ra) polished to nearly 0.7 nm. Center line average roughness (R) on the color filter pixel whose surface was polished to near 1.7 nm.
a) A transparent conductive film having a thickness of 1.76 nm or more is formed, and 3) A spacer pillar is formed on the transparent conductive film by photolithography using a photosensitive resin, and a color filter with a spacer pillar is manufactured. It is a manufacturing method of an attached color filter.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A color filter with spacer columns according to the present invention will be described below based on its embodiments. FIG. 1 is a sectional view schematically showing an embodiment of a color filter with spacer columns according to the present invention. As shown in FIG. 1, a color filter (10) with spacer pillars according to the present invention comprises a black matrix (2), color filter pixels (3), a transparent conductive film (4), and a spacer on a glass substrate (1). The pillars (5) are sequentially formed.

The center line average roughness (Ra) of the surface (A) of the transparent conductive film (4) is 1.76 nm or more. That is, the spacer pillar (5) has a center line average roughness (Ra) of 1.
It is formed on the transparent conductive film (4) having a thickness of 76 nm or more.
Further, the center line average roughness (Ra) of the surface (B) of the color filter pixel (3) was polished to be close to 1.7 nm. That is, the transparent conductive film (4) is formed on the color filter pixel (3) having a center line average roughness (Ra) of about 1.7 nm. The center line average roughness (Ra) of the transparent conductive film (4) is preferably 1.76 nm or more and about 5 nm or less.

The adhesion strength between the transparent conductive film (4) and the spacer pillar (5) depends on the materials of the transparent conductive film (4) and the spacer pillar (5), the cleanliness of the surface of the transparent conductive film (4), the spacer pillar (5). 5), which is determined by the horizontal cross-sectional area, process conditions, etc.
When the horizontal cross-sectional area of the spacer column is reduced to about 8 × 8 μm, the surface (A) of the transparent conductive film (4), which is the base of the spacer column (5), is roughened and the spacer column (5) The larger the contact area of the bottom surface of) to the underlying layer is, the transparent conductive film (4)
We paid attention to the fact that the anchor effect of No. 2 becomes large and the adhesion strength is improved.

Generally, when a color filter pixel (3) is formed by photolithography using a photosensitive coloring resin, the center line average roughness (Ra) of the surface of the formed color filter pixel (3) is several nm. ing. In addition, the surface of the color filter pixel (3) in this state has a small amount of residue generated during the process of forming the color filter pixel (3) by photolithography, but it is transparent to remove this residue. Polishing treatment is performed before forming the conductive film (4).

That is, this polishing treatment is carried out in order to prevent the residue from disturbing the adhesion between the color filter pixel (3) and the transparent conductive film (4). However, if this polishing process is excessively performed, the surface of the color filter pixel (3) becomes smooth, and thus the surface of the transparent conductive film (4) formed on the color filter pixel (3) becomes smooth. However, the adhesion strength between the transparent conductive film (4) and the spacer columns (5) becomes small.

A sample was specifically prepared, and the relationship between the adhesion strength of the spacer column and the center line average roughness (Ra) of the transparent conductive film was determined as follows. <Preparation of Sample> First, a color filter pixel having a surface center line average roughness (Ra) of about 5 nm, 4 nm, and 3 nm was formed on a glass substrate by photolithography using a photosensitive coloring resin. The surface of this color filter pixel was polished to have a center line average roughness (Ra) of approximately 2.0 to 1.0 nm. Then, a transparent conductive film was formed into a sample.

This polishing was performed using a flat plate polishing machine.
JIS hardness 8 as a polishing pad on the plate of a flat plate polishing machine
A polyurethane foam cloth of No. 5 was attached, and a polishing liquid in which an alumina abrasive having a primary particle of 0.1 μm (secondary particle of 30 μm) was dispersed was used as the polishing liquid, and the polishing liquid was dropped on a polishing pad. The film surface side was placed face to face, the polishing pressure was about 1.5 × 10 ⁴ Pa, and the rotation speed was about 30 rpm. Further, as the transparent conductive film, ITO (Indi
um Tin Oxide) was formed into a film having a thickness of 150 nm by a sputtering method. Color filter pixels before polishing, color filter pixels after polishing, and I of the obtained sample
Table 1 shows the center line average roughness (Ra) after the TO film formation.

[0016]

[Table 1]

As shown in Table 1, by polishing the color filter pixels, the sample 1 having a surface roughness of about 5.2 nm before polishing was polished to a center line average roughness of about 1.7 nm after polishing, and so on. Sample 2 having a pre-polishing of about 4.1 nm had a centerline average roughness (Ra) of about 1.3 nm after polishing and Sample 3 having a pre-polishing of about 3.2 nm had a centerline average roughness (Ra) of about 1.1 nm.
The center line average roughness (Ra) of the sample surface on which the ITO film was formed after polishing to the color filter pixel was 1.761 nm, respectively.
It became 1.386 nm and 1.201 nm.

The center line average roughness (Ra) is measured by A
FM (Atomic Force Microscop)
y), atomic force microscope) was used. Specifically, a scanning probe microscope system SPI3800 (trade name, system number) manufactured by Seiko Instruments Inc., and a multi-functional sample SPM unit (trade name, model number) were used. This system has the performance of vertical tracking range: 5 μm or more and horizontal / vertical resolution (contact AFM): 0.2 nm (in-plane) /0.01 nm (vertical).

<Evaluation of Adhesion Strength> For the evaluation method of the adhesion strength of the spacer pillar (5) to the transparent conductive film (4), for example, 1) an adhesive tape is adhered to the transparent conductive film on which the spacer pillar is formed. After that, peel off the adhesive tape and observe the peeling state of the spacer pillars. For example, 2) Wash the transparent conductive film on which the spacer pillars are formed with a sponge brush to remove the spacer pillars. Although a simple method such as a brush method for observing can be mentioned, none of these methods is suitable because it is not possible to detect the peeling of the spacer pillars that occur during the cleaning process in the panel assembly process of the liquid crystal display device. .

Further, for example, 3) there is a swab rubbing method in which the transparent conductive film on which the spacer columns are formed is rubbed with a cotton swab and the peeled state of the spacer columns is observed, but it is not suitable for quantitative evaluation. In this evaluation, an ultrasonic method was used in which the sample was immersed in an ultrasonic bath filled with pure water and the state of the spacer column peeling was observed. This method is excellent in detection accuracy of the peeling state of the spacer column, and can perform quantitative evaluation.

Further, the evaluation of the adhesion strength was carried out under a washing condition which is more severe than the washing treatment in the panel assembling process of the liquid crystal display device. That is, even if peeling did not occur in the actual cleaning treatment, in the present evaluation, it was performed under the condition that peeling occurred in most of them. Specifically, Honda Electronics Co., Ltd .: Powerful 3 frequency multi ultrasonic cleaner Model W-
Using 118, the sample was immersed in an ultrasonic bath at 28 kHz for 120 seconds, and the state where the spacer columns were peeled off was observed after drying with N ₂ purge. The results of the observation are shown in Table 2. The vibrator of this ultrasonic cleaning machine is a Langevin type vibrator with special bolts.

[0022]

[Table 2]

As shown in Table 2, in the evaluation by the above-mentioned ultrasonic method, the spacer column residual rate of sample 1 is 50.2%, but this sample 1 does not peel off in the actual cleaning process. That is, the spacer columns having a size of about 8 × 8 μm do not peel off when formed on the transparent conductive film having a center line average roughness (Ra) of 1.76 nm or more. The sample is one in which one spacer column is formed on each of 225 color filter pixels. 50.2% of the spacer column residual rate shown in Table 2 represents [{total spacer columns (225) -peeled spacer columns (112)} / total spacer columns (225))] × 100.

[0024]

EFFECTS OF THE INVENTION The present invention is a color filter with spacer pillars, in which the spacer pillars are formed on a transparent conductive film having a center line average roughness (Ra) of 1.76 nm or more. Even if the spacer pillar is as small as approximately 8 × 8 μm, the spacer pillar may be peeled off from the transparent conductive film in the cleaning process after the spacer pillar is formed, the inspection process, and the cleaning process in the panel assembly process of the liquid crystal display device. It becomes a color filter with spacer pillars.

Further, according to the present invention, 1) the center line average roughness (R) is measured on the surface of the color filter pixel formed on the glass substrate.
a) polishing to near 1.7 nm, 2) forming a transparent conductive film having a center line average roughness (Ra) of 1.76 nm or more on the color filter pixel, and 3) forming spacer columns on the transparent conductive film. Since we manufacture color filters with spacer pillars,
Even if the size and shape of the spacer pillar is small, such as a circle of about 8 × 8 μm, the spacer pillar does not come off from the transparent conductive film during the cleaning process in the panel assembly process of the liquid crystal display device. A method of manufacturing a color filter is provided.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing an embodiment of a color filter with spacer columns according to the present invention.

[Explanation of symbols]

1 ... Glass substrate 2 ... Black matrix 3 ... Color filter pixel 4 ... Transparent conductive film 5: Spacer pillar 10 ... Color filter with spacer columns according to the present invention

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H048 BA45 BA48 BB08 BB10 BB28                 2H089 LA09 MA07X NA05 NA14                       NA15 NA17 QA14 TA12                 2H091 FA02Y FB04 FC10 FC15                       GA01 GA03 GA08 LA12 LA15

Claims (3)

[Claims] 1. A color filter with a spacer column, in which at least a color filter pixel, a transparent conductive film, and a spacer column are sequentially formed on a glass substrate, the spacer column having a center line average roughness (Ra) of 1. A color filter with a spacer pillar, which is formed on a transparent conductive film having a thickness of 76 nm or more. 2. The center line average roughness (R
2. The color filter with a spacer pillar according to claim 1, which is a) a transparent conductive film formed on a color filter pixel whose surface is polished to a thickness of approximately 1.7 nm. 3. A method of manufacturing a color filter with spacer columns, 1) at least a color filter pixel is formed on a glass substrate, and the surface of the color filter pixel has a center line average roughness (Ra) of approximately 1.7 nm. 2) Center line average roughness (Ra) The center line average roughness (R) was measured on the color filter pixel whose surface was polished to near 1.7 nm.
a) A transparent conductive film having a thickness of 1.76 nm or more is formed, and 3) A spacer pillar is formed on the transparent conductive film by photolithography using a photosensitive resin, and a color filter with a spacer pillar is manufactured. Of manufacturing colored filter with light.