JPS59212877A - Alignment mark for preparing color film layer of multicolor image display liquid crystal apparatus and method of making same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the manufacture of a multicolor image display liquid crystal device, and particularly to an alignment mark provided on a substrate for forming a color filter layer at a predetermined position, and a method for forming the alignment mark.

Such a multicolor image display liquid crystal device, as shown in a partial cross section in FIG. A color filter layer (3) that has been dyed in a desired color, and a liquid crystal (
4).

The color filter layer is the second color filter layer, as disclosed in Japanese Patent Application No. 39667/1983 filed by the present applicant under the name of "Multicolor Image Display Liquid Crystal Device".
(a) As shown in the figure, a first color filter layer (3) and a second color filter layer (3) are formed on each electrode (21 42); In some cases, a plurality of layers may be formed, such as forming the first and second color filter layers (3) (3) on top of each other in 2). In addition, the second
In FIG. 11 and FIG. 2(+)J, the same reference numerals are given to the same parts as in FIG. 1, and the same applies to the other figures hereinafter.

By the way, the above color filter layer (3) (31) was disclosed by the present applicant in Japanese Patent Application No. 56-201987 (Japanese Unexamined Patent Publication No. 58-1988) under the title "Method for manufacturing multicolor image display device". As disclosed in the patent application, it is formed by the method shown in FIGS. 3 to 7.

As shown in the third diagram, a dyeing agent (5), for example, water-soluble protein with dichromate added as a photosensitizer, is applied onto the substrate +1j on which the electrode (2) is formed using a spinner or the like. It is applied by machine and then dried. Next, as shown in Figure 4, a predetermined pattern (for example, a position corresponding to the part where the electrode (2) is formed on the substrate surface) is placed above the layer of the dyeing agent (5). positioning and exposing the mask plate (6) for exposure of the dyeing material (pattern made photosensitive);
After curing only the required portions of the dyeing agent layer, the uncured portions were dissolved and removed with warm water, as shown in Figure 5.
A dyed layer (7) consisting of a cured film of the dyed agent (5) is obtained.

After that, as shown in the sixth figure, on the layer to be dyed (7),
Apply oil-based positive photoresist (8) and dry.
Each filter color, for example, red (print, green (q), blue (13)
If you want to dye the three colors red (■Listed (q), blue (B), among the mask plates for forming a resist layer that are prepared separately, for example, use the mask plate for exposing the resist resist for red color. (9
) is positioned and exposed to light, only the part to be dyed red is photodegraded, and developed with a special developer to form a red resisting layer 00) as shown in Figure 7, and the layer to be dyed (7) Only the desired part of the sample is dyed red.

After that, the resist dyeing layer 00) is peeled off with a solvent, etc., and in the same manner, a resist dyeing layer is formed for each color of green and blue, and then dyed, and the color filter layer (3) is colored in a predetermined arrangement. form.

The color filter layer formed by the above method has high color purity, good color balance, thin and uniform film thickness, and can be mass-produced at low cost, so it has extremely practical value. expensive.

However, during the formation of this color filter layer, the positioning of the mask plate (6) for exposing the dyeing agent and the mask plate (9) for exposing the resist dyeing resist with respect to the substrate (1) has so far been a repetitive process. there were.

In other words, the positioning method in this trench is performed by visually observing the electrode (2) formed on the substrate (1) and using the electrode (2) as a base.
, - or ■x203, etc., and a dyeing agent (5) coated on the electrode (2).
The second reason is that the photoresist has a color, which makes it difficult to identify the electrode (2) during positioning. The dyeing agent (5) is a dichromate added as a photosensitizer, so it exhibits a pale orange color. The dark green color is brown in color.

In order to overcome this difficulty, alignment marks are printed on the substrate (1) using a paint that will be visible even if it is applied to the staining agent (5) or photoresist (8) layer. However, it is difficult to obtain the necessary accuracy using general printing methods such as screen IJ printing.

This is because multicolor image display liquid crystal devices are
As shown in Figure a) and Figure 2(b), the electrode (2) and the electrode (
Since the liquid crystal between 2') displays by controlling the amount of transmitted light or reflected light using the applied voltage, misalignment of the color filter layer with respect to the electrodes may cause color shift in the image, and the dyed material may This is because positioning of the exposure mask plate (6) and the resist resist exposure mask plate (9) requires extremely high precision (normally an error within 10 μ?n).

Therefore, in order to satisfy such high precision, before applying the dyeing agent (5), for example, a colored metal oxide or the like is deposited on a part of the substrate, a photoresist is applied, and the shape of the alignment mark is formed. A possible method is to form highly accurate, colored, and easy-to-print alignment marks by layering patterned mask plates, exposing them to light, developing them, and etching them. However, this method is not suitable for mass production and is undesirable because it requires many additional complicated steps, such as a vapor deposition step, an etching step, and many other complicated steps.

Therefore, as another method, when forming the electrode (2),
When applying this soil KM staining agent (5) to form an alignment mark together with the electrode (2), this mark is transparent like the electrode, so it is difficult to identify). One possible method is to expose the alignment marks and make them easier to see by applying a mask plate to prevent the formation of a film.・However, since it is necessary to apply the dyeing agent (5) to a very uniform film thickness and it is applied with a spinner, it is not easy to apply the dyeing agent (5) through such a mask plate. isn't it.

As a method similar to the above method, the above and 11iJ
Similarly, alignment marks are formed together with the electrodes,
If you apply the staining agent without using the mask plate (naturally, the staining agent will also be applied on the alignment marks), apply wax etc. to the areas other than the alignment marks, and then apply the staining agent on the alignment marks. The dyeing agent is water''!
However, with this method, when removing wax, etc., the layer of dyeing agent may bleed or scratches may appear, which may affect the quality of the color filter layer. decreases, which is not desirable.

As described above, conventional alignment marks and their creation methods cannot obtain sufficient positioning accuracy, lack mass productivity, result in high costs, and are difficult to use when dyeing agent (5) is applied. In addition, there were many disadvantages such as damage to the layer of dyeing agent.

An object of the present invention is to provide a reference for positioning an article, such as the mask plate for exposure to dyeing agent, which is used when forming a color filter layer of a multicolor image display liquid crystal device. By providing alignment marks,
In particular, even if a material that is difficult to transmit light, such as a staining agent or photoresist, is applied to the upper layer of this alignment mark, the markings can be seen during positioning work, and it is highly accurate and simple. It is an object of the present invention to provide an alignment mark that can be formed in a similar manner, and to provide a method for creating this alignment mark.

Hereinafter, an alignment mark and a method for creating the same according to the present invention will be described with reference to the drawings.

The feature of the alignment mark according to the present invention is that the substrate (1+
When forming electrode (2), it is formed at the same time using the same old material as electrode (2) and in the same method as that, and it is applied to the alignment mark like a dyeing agent. The substance that makes this alignment mark difficult to see is the substrate (1
The reason is that two release layers, which will be described later, are formed before being applied to the first layer.

Although the method for forming the electrode (2) and the alignment mark is not specified in the present invention, a method using photoetching, for example, is suitable.

That is, first of all, as shown in Figure 8, ■n203
A material constituting a transparent electrode (hereinafter referred to as electrode material) (2-0) such as 5XO3 or 5XO3 is formed into a thin film on a substrate (1) by a known method such as sputtering or vacuum evaporation. In the present invention, this thin film (2-0) constitutes an electrode and an alignment mark, and the film thickness is as follows:
The thickness may be sufficient as long as it can function as an electrode of a liquid crystal device, and is preferably about 6 to 10 ttm, for example.

Next, as shown in Figure 9, a negative photoresist (positive type is also acceptable) is applied on the electrode material (2-0) to etch the electrode (2) and alignment marks into a predetermined pattern. Apply and dry this photoresist 0υ
The electrode forming mask plate 02 is positioned and attached above the film and exposed. This electrode forming mask plate α is
Electricity to be formed on the substrate (1)! The area (+2-a) corresponding to (2) is made transparent (the above photoresist 0υ
It is a positive type and has light shielding properties) and a mask plate with a shift pattern.

However, in the present invention, in addition to this pattern, in order to form the alignment mark, a mask plate is used which has a pattern in which the region (12-b) corresponding to the alignment mark is also transparent (light-shielding). . FIG. 10 is a partial plan view of the electrode forming mask plate Q2+ viewed from above. The mask plate +12 shown in FIG. 10 is one example, and the present invention is not limited thereto, and the alignment mark may have any shape.

As described above, the 7 otoresist (11) shown in FIG.
is exposed to light, developed, and the portions of the layer of the electrode material 00) other than those on which the electrodes and alignment marks are to be formed are exposed from the photoresist layer and subjected to etching treatment. II+ is completely removed to obtain the electrode (2) and alignment mark 03) as shown in Figure 11.

The method for forming the alignment mark described above is as follows:
This is just one example, and the present invention is not limited to this method. In short, in the present invention, the alignment mark may be formed in the same layer as the layer in which the electrode (2) is formed.

After the alignment mark according to the present invention is formed on the substrate as described above, as shown in FIG.
A release layer 04) is formed to cover 1. This release layer (
14) is before a dyeing agent etc. is applied on the substrate (1), that is, before a layer such as a dyeing agent etc. that makes the west alignment mark θ3) difficult to see is provided on the alignment mark 031. must be formed.

In addition, this release layer can be made of, for example, polyvinyl alcohol (
It is formed by applying a releasable resin such as PVA (hereinafter referred to as PVA). In addition to PVA, such releasable resins include, for example, Melcoat Clear (product name of Washin Chemical Co., Ltd.) '=! It was experimentally confirmed that Take Sky Coat S (product name of Nikka Seiko Co., Ltd.) is preferable.

Note that application of these releasable resins by, for example, screen printing is simple and suitable for mass production. However, as a result of experiments, it has been found that the film thickness is preferably about 30 to 50 μm.

However, the point is that what is formed above the alignment mark can be easily peeled off and removed, and in the present invention, the coating method and film thickness are very limited.

The substrate on which the release layer has been formed in the desired areas in this way is then coated with the dyeing agent over the entire surface and dried, and then this release layer is peeled off, at the same time the dyeing agent on the release layer is also removed. Therefore, the alignment mark is exposed, and subsequent alignment with the corresponding alignment mark attached to the dyeing agent exposure mask plate (6) becomes easy.

In addition, when positioning the mask plate for forming the resisting layer, the peeling layer formed before applying the dyeing agent (5) should be
Since it has been peeled off before positioning the dyeing agent exposure mask plate (6), it is necessary to reapply a releasable resin for each color before applying the photoresist for forming the resisting layer. be.

As described above, the alignment mark according to the present invention is formed together with the electrode in the layer in which the electrical contact necessary for manufacturing a multicolor image display liquid crystal device is to be formed, and by the same method as that. Therefore, high precision can be maintained and an improvement in the quality of multicolor image display liquid crystal devices can be expected.

However, in the alignment mark according to the present invention, the peeling layer formed on the upper layer makes it possible to easily remove a film layer such as a dyeing agent attached above together with the peeling layer to easily expose the alignment mark. This makes it very easy to see when positioning a mask board, etc.

Moreover, the alignment mark according to the present invention is formed together with the electrode, and there is no need for any other process to form the alignment mark other than applying a removable resin (step 5). It does not reduce the productivity or increase the cost of the display liquid crystal device, and since it is easy to see, positioning work is expedited and quality is stable, so it is expected to improve productivity and reduce costs.

[Brief explanation of the drawing]

FIG. 1, FIG. 2(a) and FIG. 2(b) are, respectively,
FIG. 6 is a partial vertical cross-sectional view showing a different example of a multicolor image display liquid crystal device. 3 to 7 are longitudinal cross-sectional views showing a method of forming a color filter layer in the above multicolor image display liquid crystal device. FIG. 8, FIG. 9, FIG. 11, and FIG. 12 are longitudinal cross-sectional views sequentially showing a method for forming an alignment mark according to the present invention. FIG. 10 shows a part of the first resist exposure mask plate provided with a pattern for forming alignment marks.
This is a town map. (11 (11 substrates (2) (21 electrodes (3
) (3) Color filter layer (4) Liquid crystal (5) Dyeing agent (6) Dyeing agent exposure mask plate (7) Dyeing layer (8) Photoresist (9) Mask plate
(10) Resistant layer 01) Photoresist (1 electrode formation mask plate + 131' alignment mark (1)
4) Release layer patent applicant representative Patent attorney So Takezawa −
The same patent attorney, Yo Oshima. Figure 8 Figure 10 Figure 11

Claims (2)

[Claims] (1) In a multicolor image display liquid crystal device that obtains multicolor display by using color filters laminated on electrodes, the electrodes are placed on the substrate surface on which the electrodes and the color filter layer are formed. An alignment mark for forming a color filter layer of a multicolor image display device, characterized in that it is formed of the same material and by the same method as in the above, and is provided with a release layer as an upper layer. (2) When forming an electrode on the substrate 1m on which the electrode and the color filter layer are to be formed, an alignment mark is formed using the same material as the electrode and by the same method as that, and then, 6. After forming a release layer on the upper layer of the alignment mark portion and further superimposing a required film layer on top of the release layer, removing the release layer, the upper film layer is removed together with the release layer. . A method for creating an alignment mark for creating a color filter layer of a multicolor image display device, the method comprising exposing the alignment mark.