JPH0197903A - Production of color filter - Google Patents

Abstract

PURPOSE:To flatten the surface of a substrate, on which a color filter part is formed, with an easy method by printing a pigment ink on the surface of the substrate to form the color filter part, forming a resin layer on the color filter part and pressurizing the surface of the resin layer with a roll to level the surface. CONSTITUTION:A color filter part 1 (red 1R, green 1G, blue 1B, and black 1BK) is formed by printing red, green, blue, and black ink on a substrate 11 so that the ink thickness will be 2-3mum after baking, and these ink are baked by heating. An epoxy resin to form a resin layer 21 is coated on the color filter part 1 with 3mum thickness. This substrate 11 where the resin layer 21 is coated on the color filter part 1 is allowed to pass between rolls 61 and 62 lined with silicone rubber while being pressurized, and the resin layer 21 is hardened by heating. Thus, the resin layer to be a flattened layer of the color filter part is formed very thin with the flat surface by the easy method.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a color filter used in a color liquid crystal display element.

A conventional liquid crystal display element is basically constructed by sandwiching a liquid crystal between two electrode substrates. When constructing a color liquid crystal display element, as shown in FIG. 2, three primary colors, namely red IR,
Green IG, blue IB and a light shielding layer to prevent color mixing (
A color filter portion 1 made of black (IBK) is formed on one substrate 11 in a striped or mosaic shape. In order to flatten the uneven surface of the color filter section 1, a resin layer 21 is coated on the color filter section 1 by a spin code method or the like.Next, a transparent electrode 31 is formed on the resin layer 21. is formed. A transparent electrode 32 is formed on the other substrate 12.

The liquid crystal LC is sandwiched between these two substrates 11 and 12. Reference numeral 51 denotes a sealing material for forming a liquid crystal cell between the two substrates 11 and 12 with a certain gap. After the light passes through the filter section 1 and a spectral component is selected, the amount of light transmitted is adjusted by the liquid crystal LC, which is a light shutter, and colored light is observed by humans as emitted light.

As a method of forming the above color filter portion at low cost, a method of printing pigment ink on the substrate surface using a lithographic plate, an intaglio plate, or the like has been considered.

Problems to be Solved by the Invention However, when the color filter portion is formed by the above-described printing method, the surface of the color filter becomes uneven with a size of 1 μm or more, which disturbs the alignment of liquid crystal molecules, which is an extremely undesirable problem. Especially when the gap of the liquid crystal cell is small, e.g. 5μ
In liquid crystal display elements with a size of less than m, there is a problem in that differences in cell gaps occur in some areas, causing display unevenness.

In order to improve these above-mentioned problems, a method has been proposed in which a resin layer is applied on the color filter section to reduce surface irregularities.

However, even if this method is used, the unevenness on the surface of the resin layer cannot be made sufficiently small.In our study, when the thickness of the resin layer is 3 μm, the unevenness on the surface of the resin layer is 0.
It was about 5 to 0.6 μm. - On the other hand, the thickness of the resin layer is 1
If the size is set to 0 μm, the unevenness on the surface of the resin layer will be 0.2 to 0.
．． Although it can be made as small as 3 μm, there is a problem that cranks may enter the resin layer during thermosetting of the resin layer or during formation of a transparent electrode film.

The present invention has been made in view of the above-mentioned points, and provides a method for manufacturing a color filter that can flatten the surface of a substrate on which a color filter portion is formed by a simple method.

Means for Solving the Problems In order to solve the above problems, the present invention includes a step of printing pigment ink on the surface of a substrate to form a color filter section, and forming a resin layer on the color filter section. process and
This method includes a step of flattening the unevenness on the surface of the resin layer by applying pressure with a roller.

Function: According to the present invention, the surface of the substrate on which the color filter portion is printed is flattened by the above-described manufacturing method.

There are two types of unevenness on the surface of the printed color filter section. One is relatively small irregularities caused by pigment particles in the ink, and the other is relatively large irregularities that occur when ink is transferred from a printing plate to a substrate during printing. Although the resin layer formed on the color filter portion considerably eliminates the unevenness caused by the pigment particles in the former, the unevenness caused during printing in the latter remains without being sufficiently flattened. By pressing this with a roller, the unevenness that occurred during printing is flattened.

Note that it is possible to flatten the surface of the printed color filter section by applying pressure with a roller, but according to our study, this method does not flatten sufficiently, and the surface unevenness is approximately 0.8 μm. Met.

EXAMPLE Hereinafter, a method for manufacturing a color filter according to an example of the present invention will be described with reference to the drawings.

In the present invention, first, as shown in FIG. 1, red, green, blue, and black inks are printed on a substrate 11 made of glass so that the thickness after baking is 2 μm to 3 μm.
Color filter sections 1 for each color (red IR, green IG, blue IB, black IBK) are formed. These are then heated and baked.

Next, an epoxy resin, which will become the resin layer 21 shown in FIG. 3, was coated onto the color filter portion l to a thickness of 3 μm using a roll coater method.

Further, as shown in FIG. 3, the substrate coated with the resin layer 21 on the color filter portion l is passed between rolls 61 and 62 lined with silicone rubber while being pressurized.
At this time, the rolls 61 and 62 are being rotated in the direction of the arrow shown in FIG. 3, and the substrate 11 is also being moved in the direction of the arrow shown in FIG. Thereafter, the resin layer 21 is cured by heating.

Thereby, the color filter of the present invention is obtained.

The surface of the color filter substrate thus obtained (the surface of the resin layer 41) was smooth, with only irregularities of about 0.1 μm observed.

In the above process, when the resin M21 is pressurized between the rolls, if the roll 61 is wetted with kerosene or silicone oil, the releasability between the resin layer 21 and the roll 61 will be further improved. This has a positive effect on the flatness of layer 21.

In addition, in the description of the present invention, a color filter having a configuration in which the color filter portion l is located between the substrate 11 and the transparent electrode 31 has been described, but a color filter having a configuration in which the color filter portion is located above the transparent electrode provided on the substrate is used. The present invention is also effective for color filters.

Effects of the Invention As described above, according to the present invention, the resin layer serving as the flattening layer of the color filter portion can be formed to be extremely thin and have a flat surface using an extremely simple method.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a color filter and a method for flattening a resin layer on the color filter portion, which is used to explain an embodiment of the present invention, and FIG. 2 is a cross-sectional view, which is used to explain a color liquid crystal display element. be. ■...Color filter section, 11...Substrate, 22...Resin layer, 61.62...
roll. Name of agent: Patent attorney Toshio Nakao 6'f, f
2--One come true Figure 2 I

Claims (1)

[Claims] A step of printing pigment ink on the surface of a substrate to form a color filter section, a step of forming a resin layer on the color filter section, and a step of applying pressure with a roller to flatten unevenness on the surface of the resin layer. A method for manufacturing a color filter comprising: