JPH07104516B2 - Method for manufacturing multicolor display device - Google Patents

Description

The present invention relates to a method for manufacturing a multicolor display device to which a color filter is applied, and in particular, a driving electrode is provided on the color filter in order to reduce the driving voltage. The present invention relates to a method for manufacturing a multicolor display device.

[Outline of Invention]

The present invention forms a transparent conductive film on a color filter, then coats a positive resist on the entire surface, and then exposes the positive resist from the back surface of the color filter with light of 400 nm or less using the color filter as a photomask, and develops the color filter. By etching the transparent conductive film in the gap, it is possible to accurately form the driving electrode only on the color filter though it is a very simple method.

[Conventional technology]

In recent years, liquid crystal display devices have become multicolored by combining them with color filters. At first, a color filter was installed on the driving electrode and the liquid crystal was driven through the color filter. However, as the size and the number of pixels increase, there is a strong demand for reduced voltage driving, and the voltage loss for the color filter is large. In order to avoid this, a method of forming a driving electrode on the color filter is being developed.

FIG. 4 shows an example of a multicolor liquid crystal display device using color filters. In FIG. 4, 41 is a transparent substrate made of glass, 42 is an electrode made of a transparent conductive film, and 43 is a color filter formed by an electrodeposition method, a dyeing method, a printing method or the like. In the case of the dyeing method or the printing method, 42 electrodes are not necessary. Reference numeral 44 is a drive electrode made of a transparent conductive film formed on the color filter so as to match the pattern, and is formed in the step shown in FIG. In FIG. 5 (a), 51 is a transparent substrate.
Reference numeral 52 is a transparent electrode, and 53 is a color filter, which is formed from a solution containing an electrodeposition polymer and a dye by an electrodeposition method. A transparent conductive film 5 made of ITO is formed on the entire surface of this substrate by sputtering, vapor deposition or the like.
4 is formed. In FIG. 5B, a resist 55 is applied on the entire surface of the transparent conductive film. In FIG. 5C, the photomask 56 is aligned so as to match the color filter pattern, and the resist is exposed by the light 57. In FIG. 5 (d), the resist is developed to expose the transparent conductive film in the gap between the color filters. In FIG. 5 (e), the transparent conductive film in the gap between the color filters is etched to remove the residual resist, and the drive electrode 58 is formed only on the color filter. Returning to FIG. 4, the method of manufacturing the multicolor liquid crystal device will be described. The substrate 41 having the driving electrodes 44 thus formed and the substrate 46 having the other driving electrodes 45 are opposed to each other to form a liquid crystal. By sandwiching 47, a multicolor liquid crystal display device is constructed. The multicolor liquid crystal display device configured as described above can be driven at a low voltage without a voltage loss due to the color filter.

[Problems to be Solved by the Invention]

In the method of manufacturing the multicolor liquid crystal display device described with reference to FIGS. 4 and 5, when forming the drive electrode on the color filter, a highly accurate photomask having the same pattern as the color filter pattern is required. To do. As the color filter pattern becomes finer, it is difficult to make a photomask without defects, and the photomask becomes more expensive. In addition, the alignment of the color filter and the photomask is also required at the time of exposure, and the finer the pattern becomes, the more difficult it is technically, the more complicated the apparatus and the process, and the higher the probability of failure.

[Means for Solving the Problems]

Therefore, the present invention aims to form a highly accurate driving electrode on a color filter by a simple process. The color filter itself is used as a photomask, and the transparent electrode is transparent to the color filter as a means for patterning by self-alignment. A conductive film and a positive resist are sequentially formed,
By exposing the positive resist with light of 400 nm or less from the back surface of the color filter, only the positive resist in the gaps between the color filters is exposed, and by developing and etching, the transparent electrode is accurately formed only on the color filter. Is.

[Action]

Currently, as the color filter for multi-color display devices, the three primary colors in additive color mixture, that is, red, green, and blue are often used, and their spectral characteristics show that the transmittance is almost 0 at 400 nm or less as shown in FIG. Has become. That is, it can be used as a photomask for light of 400 nm or less, and it is possible to perform elf alignment. However, in general, few light sources used for resist exposure generate only light of 400 nm or less. As a light source, a mercury lamp or a metal halide lamp is generally used. For example, the emission spectrum of a high pressure mercury lamp is g line (435 nm), h line (405 nm), i line (365n) as shown in FIG.
m) are the three main types, with some strength and spread depending on the type. Many metal halide lamps have a broad spread rather than a clear line spectrum. If the light source is i-line (365nm) that is 400nm or less
If there is a light source that hardly emits light of 400 m or more by itself, the object of the present invention can be achieved by using the light value. However, when the resist is exposed with a color filter as a photomask with an actual light source, g-line (435 nm), h-line (4 nm)
05 nm) also occurs, especially the blue filter transmits around 450 nm, so light leakage occurs, and the resist on the color filter that should not be exposed is exposed.
The transparent conductive film on the color filter is removed by development and etching.

Therefore, the present inventors have added an ultraviolet ray transmitting optical filter for blocking light of 400 nm or more having the spectral characteristic shown in FIG. 3 to the conventional light source, and the light passing through this optical filter is used as a photomask for the color filter. As a result, it was found that by exposing by self-alignment, light leakage through the color filter can be completely eliminated, and high resolution can be obtained. According to this method, by simply adding an ultraviolet transmitting optical filter to the conventional exposure light source,
The transparent electrode can be formed on the color filter with great accuracy and is extremely useful in practice.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples.

(Embodiment 1) FIG. 1 shows a sectional view of an embodiment of a multicolor liquid crystal display device according to the present invention. 11 is a substrate made of glass, 12 is a transparent electrode made of ITO, and 13 is a color filter, which is formed by applying a voltage to the transparent electrode 12 in a solution containing an electrodepositable polymer and a dye to cause electrodeposition. Reference numeral 14 is a driving transparent electrode made of ITO whose pattern is matched with that of the color filter, and is manufactured in the step shown in FIG. In FIG. 2 (a), 21 is a glass substrate and
An ITO transparent electrode 22 and a color filter 23 are formed. Furthermore, a transparent conductive film 24 made of TIO is formed thereon by sputtering, vapor deposition or the like. In FIG. 2 (b), positive resist 25 (OFPR 800 manufactured by Tokyo Ohka) is applied over the entire surface. In FIG. 2 (c), a high pressure mercury lamp is used as a light source from the rear surface of the substrate, and the ultraviolet transparent optical filter 26 is used to
The positive resist is exposed with light 27 using the color filter as a photomask. At this time, the ultraviolet transmission optical filter may be either a thin film interference type or a type in which a visible light absorbing substance is mixed in glass. In Fig. 2 (d), the positive resist was developed and the IT in the gap of the color filter
Expose O. In FIG. 2 (e), the ITO in the gap between the color filters is etched to remove the residual resist, and the drive electrode 28 is formed only on the color filter.
Neither a precise photomask nor accurate alignment is required in this process, and the defect rate was greatly improved while being simple. Hereinafter, returning to FIG. 1 and continuing the description, the substrate 11 having the transparent electrode 14 thus formed and the substrate 16 having the other driving electrode 15 are opposed to each other, and the liquid crystal 17 is held therebetween. A multicolor liquid crystal display device was manufactured. Although this multi-color liquid crystal display device was manufactured by a simple method, it had no defects due to defects and was suitable for low voltage driving.

(Example 2) The transparent electrode 12 was directly produced on the spray substrate 11 by a dyeing method in which the color filter 13 in Example 1 was formed by patterning photosensitive gelatin and dyeing it with a dye. Hereinafter, a transparent electrode 14 is formed on the color filter to form a multicolor liquid crystal display device in the same manner as in Example 1 except that the exposure light source in Example 1 is a metal halide lamp, and the same effects as in Example 1 are obtained. Was obtained.

(Comparative Example) The transparent electrode was formed on the color filter by directly irradiating the light of the light source from the back surface of the color filter without using the ultraviolet transmitting optical filter 26 in Example 1.
Light of 400 nm or more leaked on the blue filter and the resist was exposed, and the transparent electrode was not etched.

〔The invention's effect〕

As described above in detail in the examples and comparative examples, the method for manufacturing a multicolor display device according to the present invention does not require a precise photomask or accurate alignment as in the conventional case, and a color filter As a mask, a highly accurate transparent electrode pattern can be formed on a color filter by self-alignment. Also, since all that is needed is an optical filter that produces light of 400 nm or less, it is a multicolor display device suitable for low-voltage drive that is extremely simple and has no defects without complicating conventional manufacturing equipment. Can be manufactured in large quantities.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a multicolor display device according to the present invention, FIGS. 2A to 2E are cross-sectional views showing a process for manufacturing a transparent electrode on a color filter according to the present invention, and FIG. 3 is each filter. Of the spectral characteristics of the light source and the luminance spectrum of the light source,
FIG. 5 is a sectional view of a conventional multicolor display device, FIG.
FIG. 6E is a sectional view showing a conventional process for producing a transparent electrode on a color filter. 11,16,21,41,46,51 …… Substrate 12,14,15,28,44,45,58 …… Transparent electrode 13,23,43,53 …… Color filter 17,47 …… Liquid crystal 24, 54 …… Transparent conductive film 25,55 …… Resist 26 …… Ultraviolet transmitting optical filter 56 …… Photo mask 27,57 …… Light

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-63-70828 (JP, A) JP-A-59-114572 (JP, A) JP-A-59-189318 (JP, A) JP-A-62- 32616 (JP, A)

Claims (4)

[Claims] 1. A method of manufacturing a multicolor liquid crystal display device using a color filter, the step of forming a plurality of color filters on a transparent substrate, the step of forming a transparent conductive film on the entire surface of the color filter, and the step of forming a transparent film on the color filter. Step of applying a positive resist on the entire surface of the conductive film. Step of exposing the positive resist with light of 400 nm or less from a light source on the back surface of the substrate using the color filter as a photomask. After development, the transparent conductive film in the gap between the color filters is etched. A method of manufacturing a multicolor display device, comprising the step of leaving the transparent conductive film only on the color filter. 2. The light emitting device according to claim 1, wherein the light of 400 nm or less is created by adding an optical filter that blocks light of 400 nm or more and transmits light of 400 nm or less to a light source. Manufacturing method of multicolor display device. 3. The method for manufacturing a multicolor display device according to claim 1, wherein the light source is a mercury lamp or a metal halide lamp. 4. A color filter is formed on a substrate to form a plurality of conductive layers which are insulated from each other, and then a solution in which an electrodeposition polymer and a dye are dispersed is formed on the conductive layers. The method for manufacturing a multicolor display device according to claim 1, wherein the multicolor display device is selectively formed by electrodeposition.