JP2000298208A - Color filter, method of manufacturing the same, and EL display and liquid crystal display using the same - Google Patents

Abstract

(57) Abstract: Provided is a low-resistance color filter with a bus electrode and a manufacturing method thereof that minimizes manufacturing steps such as a transparent electrode patterning step using an etchant. A plurality of stripe-shaped relief patterns (3) having a reverse tapered cross-section are formed on a substrate (1) and a metal pattern formed between the relief patterns and in contact with a tapered portion of one of the relief patterns. 7 and at least a transparent electrode 8 formed on the relief pattern and in contact with the metal pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter with a bus electrode which can be used for an organic electroluminescence display (hereinafter, referred to as an organic EL display) or a liquid crystal display as a home / business information display terminal, and a method of manufacturing the same. And a manufacturing process such as a transparent electrode patterning process using an etchant is minimized.

[0002]

2. Description of the Related Art Organic EL displays and liquid crystal displays are gradually becoming popular in the future as flat panel displays replacing cathode ray tubes (CRTs) because of their advantages such as light weight, space saving and low power consumption. It is expected that CRTs will eventually replace CRTs due to advances in technology and high definition technology.

The structure of an organic EL display has a structure in which a light emitting medium composed of an organic thin film is sandwiched between a transparent anode and a cathode, and an example thereof is disclosed in Japanese Patent Application Laid-Open No. 63-264692. A two-layer structure in which such a hole transport layer and an electron injection light emitting layer are laminated, or a three layer in which a hole transport layer, an organic light emitting layer, and an electron transport layer are laminated as disclosed in JP-A-2-216790. There are structures.

Here, as a method of colorizing the organic EL display, there are a method of causing the light emitting medium to emit R, G, and B light, and a method of causing the light emitting medium to emit white light, but passing through the R, G, and B color filters. There is a method of coloring R, G, B.

The anode material needs to have a small energy barrier difference from the hole injection / transport layer and a high translucency. Generally, an oxide of indium and tin (hereinafter referred to as an oxide) is used.
ITO) and oxides of magnesium and zinc are used.

On the other hand, a liquid crystal display has a structure in which, for example, in the case of a simple matrix drive using a nematic liquid crystal or a smectic liquid crystal, the liquid crystal is sandwiched between opposing substrates in which stripe electrodes are orthogonal to each other.

Here, as a method of colorizing a liquid crystal display, although a backlight emits white light,
There is a method of transmitting R, G, B color filters and coloring R, G, B.

[0008] As the electrodes, ITO having a resistivity of about 20 Ω / cm ² is generally used.

In any of the displays, it is necessary to narrow the electrode pattern width and lengthen the wiring in order to increase the display area and the capacity of the display contents. However,
The above-mentioned ITO electrode has higher electrical resistance than general good conductive metals, such as copper, aluminum, chromium, and silver. Therefore, it causes problems such as uneven brightness, increased heat generation and increased power consumption due to the delay effect of the voltage signal. There is.

For this reason, many techniques have been disclosed to reduce the electrical resistance of the ITO electrode. JP Hei 10-1
In the publication No. 06751, the stripe-shaped ITO transparent electrode is patterned, and a metal pattern having a lower electric resistance than the ITO is provided on both sides in parallel, so that the electric resistance is reduced to 1/10.
There is a statement that will be. However, in this method, the thickness of the metal pattern must be set to about 70% of the thickness of the ITO pattern in order to prevent the step of the organic thin film from being cut by the step between the ITO and the metal pattern. It is difficult to reduce the resistance of the device.

In JP-A-2-63019, first, aluminum is patterned in a stripe shape. Thereafter, an insulating film is applied on the entire surface, and patterned by photolithography so that a reverse tapered through hole is formed on the aluminum. Next, ITO and aluminum are brought into contact with each other through through holes by depositing ITO by sputtering. Finally, using an etchant
A technique for patterning ITO has been disclosed. By using such an ITO electrode with a bus electrode, the electric resistance can be reduced to 1 /
It is stated that it will be 100 to 1/300. However, as described above, each of the metal film, the insulating film, and the ITO film requires a patterning step after the film formation, and there is a problem that the manufacturing process is complicated.

In Japanese Patent Application Laid-Open No. 9-230318, after a metal is patterned in a stripe shape on a glass substrate, the space between the metal wirings is buried flat with an insulator. Next, after the ITO film is formed, patterning is performed using an etchant. However, this method causes a problem if the edge of the ITO pattern is slightly shifted from the edge of the metal wiring. If it protrudes, there is a problem of color mixing when colorized. If it is shifted in the opposite direction, there is a problem that the etching solution used for patterning the ITO causes corrosion of the metal wiring.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a color filter having a low-resistance bus electrode and a transparent electrode patterning method using an etching solution. An object of the present invention is to provide a manufacturing method in which manufacturing steps such as manufacturing steps are minimized, and a display and a liquid crystal display using the manufacturing method.

[0014]

According to a first aspect of the present invention, a plurality of stripe-shaped relief patterns having a reverse tapered cross section, which are colored chromatically, are formed on a substrate. A color filter comprising at least a metal pattern in contact with a tapered portion of one of the relief patterns and a transparent electrode formed on the relief pattern and in contact with the metal pattern.

The invention described in claim 2 is the first invention.
The color filter is characterized by having a stripe-shaped partition pattern extending in a direction substantially perpendicular to the direction in which the metal pattern extends on the color filter.

[0016] The invention according to claim 3 provides the invention according to claim 1.
Or a light emitting medium and a cathode are sequentially laminated on the color filter according to any one of the above items.

The invention described in claim 4 is the first invention.
Or a liquid crystal display wherein the color filter according to any one of 2) and a rear substrate are overlapped, and liquid crystal is injected into a gap therebetween and sealed.

Further, according to a fifth aspect of the present invention, there is provided a method for forming a plurality of stripe-shaped relief patterns having a reverse tapered cross-section on a substrate, the method comprising: A step of forming a metal thin film, a step of patterning the metal thin film in contact with one tapered portion, and separating it from the other tapered portion, and forming a metal pattern between the relief patterns; A method of manufacturing a color filter, comprising a step of patterning a transparent electrode at the same time as forming a film thereon.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A process for manufacturing a color filter according to the present invention will be described below with reference to the drawings.

As the substrate 1 used in the present invention, a light-transmitting insulating substrate, for example, a quartz substrate, a glass substrate, a plastic substrate, or the like can be used.

First, R (red), G (green), B
A negative resist 2 in which a pigment or dye of one color selected from chromatic colors such as (blue) and preferably a UV-absorbing substance is dispersed is applied and dried (see FIG. 1A). ). Here, as the UV absorbing substance, besides organic substances such as benzophenone type, phenylsalicylic acid type, cyanoacrylate type, benzotriazole type and oxalic acid anilide type, inorganic substances such as glass powder and cerium oxide powder can be used.

Next, UV exposure is performed using a photomask on which a stripe pattern having an appropriate pitch is formed.
It is exposed up to a certain depth from the surface of the resist,
The portion below that remains unexposed. When development is performed in this state, the exposed portion of the surface remains undissolved but the unexposed portion is removed. Therefore, if conditions are selected, a relief pattern 3 having a reverse tapered cross section can be obtained. To improve the reverse taper shape, it is necessary to use UV
Preferably, an absorbent material is included.

The above steps are performed by, for example, R (red), G
By performing (green) and B (blue), a plurality of striped relief patterns are completed on the substrate (FIG. 1).
(See (b)).

Next, a metal thin film 4 is formed on the substrate 1 having the relief pattern 3 by vapor deposition or plating.
(See FIG. 1 (c)). Then, a resist 5 is applied on the metal thin film 4 (see FIG. 1D), and a resist pattern 6 is formed by a predetermined photolithography method (FIG. 1).
(e)), the metal thin film 4 is separated from the one tapered portion (3A) by etching, and is substantially in contact with the other tapered portion (3B). By patterning, a metal pattern 7 is formed (see FIG. 1 (f)). Hereinafter, this metal pattern 7 is called a bus electrode.

The conductive material used for the bus electrode is N
It is preferably selected from i, Cu, Cr, Fe, Co, Au, Ag, Pt, Rh, Pb, Sn or alloys containing one or more of these metal elements.

It is desirable that the electric resistance between both ends of the bus electrode be as low as possible. The electric resistance value is desirably 1000Ω or less, and more desirably 100Ω or less. Further, the width of the bus electrode is preferably not more than 1/2 of the maximum width of one pixel, and more preferably not more than 1/4, in order to secure the aperture ratio of the display. 1/20 to secure electrical resistance
It is desirable that this is the case.

It is desirable that the height of the bus electrode is usually 0.1 μm or more, and it is desirable that the height is equal to the height of the relief pattern having the reverse tapered shape. Also, to prevent the bus electrode from restricting the light emission direction and narrowing the viewing angle,
It is desirable to form it at a height of 50 μm or less.

For example, for a width of 100 μm, 2 × 10 ⁻⁶ Ω / c
using a copper-based metal with a resistivity of m
m, the width of the bus electrode must be equal to the pixel width.
If the quarter is 25 μm and the height is 5 μm, the electric resistance between both ends of the bus electrode is about 10Ω. This value is several hundredth of the resistance value of the ITO pattern alone.

Further, by previously forming a layer made of a light-absorbing substance at a contact portion between the bus electrode and the substrate, this portion also has a function of preventing reflection of external light and a function as a black stripe. It is possible to improve the contrast of the display.

Next, ITO, which is a transparent conductive film, is formed by a sputtering method. Here, as the transparent conductive film,
ITO, indium zinc oxide composite oxide, zinc aluminum oxide and the like can be used. As can be seen from FIGS. 1 (f) and (g), the metal pattern is separated from one tapered portion (3A) and is in contact with the other tapered portion (3B).
The O film is patterned at the same time as the O film is formed, and the transparent electrode 8 is formed. Thereby, since there is no step between the metal pattern and the transparent electrode, disconnection of the step can be prevented. In addition, since the ITO patterning step can be omitted, the bus electrode can be prevented from being corroded by an etchant used for etching the ITO.

FIG. 1 (h) is a perspective view of the completed color filter with bus electrodes, which is the color filter according to the first aspect and the manufacturing method according to the fifth aspect.

Further, it is preferable to fill the gap 9 between the relief patterns with a negative resist or the like.

Further, a manufacturing process of an organic EL display using a color filter with a bus electrode (claim 3) will be described with reference to FIG.

A resist layer 10 is formed on the color filter (see FIG. 2 (a)), and a direction substantially perpendicular to the extending direction of the metal pattern (the direction of arrow A in FIG. 1 (h)) is obtained by photolithography. A stripe-shaped partition pattern (see FIG. 2 (b)) extending in the direction of arrow B in FIG. 1 (h) is formed. In this method, the gap 9 between the relief patterns shown in FIG.
Can be filled with a resist for forming a partition pattern, so that a hole filling step can be omitted. In addition,
The width of the gap is desirably 1 to 500 μm.

This “work” -shaped partition pattern is made of organic EL.
This is a partition for attaching and separating the cathode of the display at the same time (Japanese Patent Application Nos. 10-117236 and 10-247412).
. The formation principle will be described with reference to FIG.

A negative resist layer 18 mixed with a pigment or dye, preferably a UV-absorbing substance, is formed on a substrate 19, and a UV is applied by using a photomask 16 on which a stripe-shaped pattern having an appropriate pitch is formed. Exposure 15 is performed (FIG. 3
(See (a)). At this time, the resist is exposed up to a certain depth from the surface of the resist (the photosensitive portion 17 is formed), but the UV light is absorbed by the resist, so that it cannot reach the deep portion and the lower portion remains unexposed. When development is performed in this state, the photosensitive portion on the surface remains without being dissolved, but the unexposed portion is removed (
(See FIG. 3 (b)). Since the portions below the surface layer are all unexposed portions, development proceeds from the side and a skirt having a forward taper is formed (see FIG. 3 (c)). Also, by selecting the conditions, it becomes possible to form the "work" -shaped partition pattern 20 having a longer skirt than the eaves (see FIG. 3D).

On the substrate on which the partition pattern has been formed,
An EL display can be manufactured by sequentially vacuum-depositing a luminescent medium including a hole transport layer and an electron transport luminescent layer, and a metal cathode serving as a second electrode line, and sealing them with a sealing layer (FIG. 2 ( c), (d)). Note that an inorganic light emitting material can be used for the light emitting medium.

The manufacturing process of a liquid crystal display (claim 4) using the color filter of the present invention will be described.

Forming a resist layer on the color filter,
A stripe-shaped partition pattern extending in a direction substantially perpendicular to the extending direction of the metal pattern is formed by photolithography (claim 2). According to this method, the gap 9 between the relief patterns in FIG. 1 (g) can be filled with the resist 10 for forming the partition pattern, so that the hole filling step can be omitted. Next, the color filter and the rear substrate are overlapped, and the two are adhered to each other by a partition pattern by heating, a liquid crystal is injected, and the periphery is sealed, whereby a liquid crystal display can be manufactured. In addition,
A liquid crystal display can also be formed by maintaining the distance between the color filter and the rear substrate with beads, injecting liquid crystal, and bonding and sealing the periphery without providing a partition pattern.

[0040]

EXAMPLES [Production of Color Filter] A negative resist in which a red pigment and a UV-absorbing substance were dispersed was applied and dried on a glass substrate to form a resist layer.

Next, using a photomask on which a stripe pattern having a pitch of 300 μm and a width of 20 μm is formed,
After the resist layer was exposed to UV, it was developed to form a striped relief pattern having a reverse tapered cross section.

The pigment was changed to green and blue, and the above steps were repeated to form a plurality of striped relief patterns.

Next, a metal thin film made of Cu having a thickness of about 3 μm, which is almost the same as that of the tapered portion, was formed on a glass substrate on which a stripe-shaped relief pattern having an inversely tapered cross section was formed.

Next, a resist layer was formed on the metal thin film, exposed to UV through a photomask, and developed to form a resist pattern.

Next, after etching the metal thin film, the resist pattern 6 is removed, and the metal pattern is cut off from one of the tapered portions and adhered to the other tapered portion. A patterned bus electrode was formed.

Next, as a transparent electrode, a 0.1 μm film of ITO was formed by sputtering. At this time, since there was a stripe-shaped relief pattern having an inversely tapered cross section on the substrate, the transparent electrode was formed at the same time as the transparent electrode was formed, and the transparent electrode was cut off at the tapered portion.

Further, on the color filter, a partition wall forming material is applied on the same plane as the extending direction of the metal pattern, and is patterned by photolithography to form a stripe-shaped “work” extending substantially perpendicular to the metal pattern.
-Shaped partition pattern (Japanese Patent Application No. 10-117236, Japanese Patent Application No. 10-247
No. 412), and a color filter with a bus electrode with a partition pattern was completed. It should be noted that the partition wall forming material filled the gaps between the relief patterns.

[Manufacture of EL Display] On the color filter provided with the partition pattern, a luminescent medium comprising a hole transport layer and an electron transport luminescent layer, and a metal cathode serving as a second electrode line are sequentially vacuum deposited and sealed. An organic EL display was fabricated by sealing with a stop layer.

[Manufacture of Liquid Crystal Display] The color filter provided with the partition pattern is superposed on the rear substrate, and heated and adhered to each other with the partition pattern keeping the distance therebetween, nematic liquid crystal is injected, and the periphery is sealed. As a result, a liquid crystal display was produced.

[0050]

As described above, according to the first aspect of the present invention, a metal pattern (metal bus electrode) having a low electric resistance is provided between the relief patterns in parallel with the transparent electrode line. In addition, the electric resistance of the transparent electrode can be reduced to several hundredths of the case where only the transparent electrode is used. Further, since there is no step between the transparent electrode and the metal pattern, disconnection of the step can be prevented.

According to the second aspect of the present invention, the transparent electrode can be patterned at the same time as the film formation, and the patterning step of the transparent electrode can be omitted.

According to the third aspect of the present invention, an EL display having a bus electrode with low electric resistance can be obtained.

According to the fourth aspect of the present invention, a liquid crystal display having a bus electrode with low electric resistance can be obtained.

According to the fifth aspect of the present invention, the color filter according to the first aspect can be easily manufactured.

[0055]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a method for manufacturing a color filter of the present invention.

FIG. 2 is an explanatory diagram when a color filter of the present invention is used for an EL display.

FIG. 3 is an explanatory view showing the principle of forming a “work” -shaped partition pattern.

[Explanation of symbols]

Reference Signs List 1 substrate 2 resist layer 3 relief pattern 3A side where taper of relief pattern is not in contact with bus electrode 3B side where taper of relief pattern is in contact with bus electrode 4 metal thin film 5 resist layer 6 resist pattern 7 metal pattern (bus electrode) 8 transparent electrode Reference Signs List 9 gap between relief patterns 10 partition pattern 11 relief pattern 12 light emitting medium 13 cathode 14 sealing layer 15 UV exposure light 16 photomask 17 photosensitive part 18 resist layer 19 substrate 20 partition pattern

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 33/26 H05B 33/26 Z (72) Inventor Katsuhiro Suzuki 1-5-1, Taito, Taito-ku, Tokyo F-term in Toppan Printing Co., Ltd. (Reference) 2H048 BA45 BB02 BB07 BB08 BB14 BB41 BB44 2H091 FA02Y FA14Y FA43X FA44X FB08 FB12 FB13 FC23 GA01 GA02 GA03 LA12 3K007 AB04 AB06 AB18 BA06 BB06 CA01 CB03 CB01 DA01

Claims (5)

[Claims] A plurality of stripe-shaped relief patterns colored in a chromatic color and having an inversely tapered cross section, and a metal pattern formed between the relief patterns and in contact with a tapered portion of one of the relief patterns. And a transparent electrode formed on the relief pattern and in contact with the metal pattern. 2. A color filter having a stripe-shaped partition pattern extending in a direction substantially perpendicular to a direction in which a metal pattern extends on the color filter according to claim 1. 3. An EL display comprising: a luminescent medium and a cathode sequentially laminated on the color filter according to claim 1 or 2. 4. A liquid crystal display, wherein the color filter according to claim 1 and a back substrate are superimposed, and a liquid crystal is injected into a gap therebetween and sealed. 5. A step of forming a plurality of stripe-shaped relief patterns colored in a chromatic color and having an inversely tapered cross section on a substrate, a step of depositing a metal thin film on the substrate having the relief pattern, The metal thin film is in contact with one tapered portion, and is patterned so as to be separated from the other tapered portion, a step of forming a metal pattern between the relief patterns, on the relief pattern,
A method of manufacturing a color filter, comprising: a step of patterning a transparent electrode at the same time as applying a film.