JP2996873B2 - Method for manufacturing resin substrate for liquid crystal display element, resin substrate for liquid crystal display element, and liquid crystal display element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a resin substrate for a liquid crystal display element having an electrode pattern on the surface, a resin substrate for a liquid crystal display element, and a liquid crystal display element.

[0002]

2. Description of the Related Art A resin substrate for a liquid crystal display element having an electrode pattern on its surface (hereinafter referred to as an electrode laminated resin substrate) has been conventionally manufactured through the steps shown in FIGS. That is, as shown in FIG. 1A, first, a flat resin substrate 51 is manufactured. This resin substrate 51
Usually, a pair of molding dies (not shown) are arranged to face each other with a molding space corresponding to the thickness dimension of the resin substrate 51 therebetween, and molding is performed by casting a transparent resin into the molding space.

After that, as shown in FIG. 1B, the surface of the resin substrate 51 is ITO-coated by magnetron sputtering or the like.
A transparent conductive film 52 made of (Indium Tin Oxide) is laminated. Then, as shown in FIG.
2 is patterned into a predetermined electrode pattern by wet etching, whereby the above-described electrode laminated resin substrate is manufactured.

In the electrode laminated resin substrate as described above, as shown in FIGS. 1D and 1E, a top coat film 53 as an electrode protection insulating film and an alignment film 54 are further formed on the electrode forming surface. The layers are sequentially stacked (for example, see JP-A-4-3066).
No. 16, publication No. 16).

[0005] A pair of resin substrates obtained in this manner are opposed to each other, and a liquid crystal is sealed between them to produce a liquid crystal display element comprising the resin substrate.

[0006]

However, in the conventional manufacturing method described above, after the resin substrate 51 is formed,
Since the transparent conductive film 52 is formed on the entire surface of the resin substrate 51,
The stress caused by the difference in the coefficient of linear expansion between the resin substrate 51 and the transparent conductive film 52 is not dispersed. As a result, the process of lowering the temperature from the high temperature state to the room temperature during the formation of the transparent conductive film 52 and the subsequent temperature increase There is a problem that cracks occur in the transparent conductive film 52 during the processing.

On the other hand, if the heat resistance of the resin as the substrate material is low, the transparent conductive film 52 needs to be sputtered without heating the resin substrate 51 or formed by low-temperature sputtering. The transparent conductive film 52 formed under such conditions
Is limited in its densification. As a result, for example, there is a problem in that the transparent conductive film 52 is cracked or peeled off by a heating process in a baking step or the like necessary for forming the top coat film 53 thereafter.

Further, if the glass transition temperature (Tg) of the resin as the substrate material is low, the top coat film 53 cannot be heat-treated at a temperature higher than Tg.
Only those with low film strength can be obtained. Similarly, the alignment film 54
However, since heat treatment cannot be performed at a temperature higher than Tg, there is a problem that it is difficult to obtain a material having good orientation characteristics.

In order to reduce these problems, a resin material having a high heat resistance of, for example, 120 ° C. or more is used as a substrate material corresponding to a top coat film or an alignment film which needs to be formed by a high temperature process. Must be selected. Also,
The material of the top coat film 53 and the alignment film 54 is
For example, it is necessary to select a material having a Tg of 1 or less, and the selection range of each material is greatly restricted. As a result, there is a problem that the manufacturing cost is increased.

Further, in the above-described electrode laminated resin substrate, a step corresponding to the thickness of the transparent conductive film 52 is formed at a portion where the electrode pattern is formed after the patterning of the transparent conductive film 52 and at a portion where the electrode pattern is not formed. Even when the film 53 and the alignment film 54 are formed, the above-mentioned steps remain as they are, and the surface cannot be smooth. For this reason, in a liquid crystal display element manufactured using such a resin substrate, color unevenness and display unevenness due to non-uniform cell gap are caused, and there is a problem that display quality is deteriorated.

[0011]

According to a first aspect of the present invention, there is provided a method of manufacturing a resin substrate for a liquid crystal display element, comprising: a pair of molding dies sandwiching a predetermined molding space; In a method of manufacturing a resin substrate for a liquid crystal display element, which sets a molding position opposite to the molding space and fills the molding space with a transparent resin to form a resin substrate, the molding surface facing the molding space in one molding die is transparent. Form a conductive film,
After patterning the transparent conductive film into a predetermined electrode pattern, the molding die is set at a molding position and the transparent resin is filled into a molding space, and then the molded body made of the transparent resin is molded together with the transparent conductive film from the molding surface. By peeling, a resin substrate with electrodes is manufactured.

According to a second aspect of the present invention, there is provided a method of manufacturing a resin substrate for a liquid crystal display element according to the first aspect, wherein the molding surface is formed as a smooth surface, and the transparent conductive film is formed on the smooth surface. It is characterized by:

According to a third aspect of the present invention, there is provided a method of manufacturing a resin substrate for a liquid crystal display element, comprising the steps of:
It is characterized in that the molding surface is subjected to a surface treatment for improving releasability, and the transparent conductive film is formed on the treated surface.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a resin substrate for a liquid crystal display element according to the first, second or third aspect, wherein a coating layer provided to cover a surface of the resin substrate with electrodes is formed on the molding surface. After the film is formed in advance, and then the film formation and patterning of the transparent conductive film and the molding of the transparent resin are sequentially performed, the molded body is separated from the molding surface together with the coating layer and the transparent conductive film.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a resin substrate for a liquid crystal display element, wherein the coating layer is formed on a molding surface in order and the insulating film for protecting an electrode is formed. Characterized by comprising a laminated body of:

According to a sixth aspect of the present invention, there is provided a method of manufacturing a resin substrate for a liquid crystal display element according to the fifth aspect, wherein fine irregularities for orienting liquid crystal are formed on the molding surface on which the alignment film is formed. It is characterized by doing.

According to a seventh aspect of the present invention, there is provided a resin substrate for a liquid crystal display element, which is manufactured by the manufacturing method according to any one of the first to sixth aspects.

According to an eighth aspect of the present invention, at least one of the liquid crystal display elements has a pair of substrates made of the resin substrate for a liquid crystal display element of the seventh aspect facing each other, and a liquid crystal is sealed between these substrates. Features.

[0019]

In the method of manufacturing a resin substrate for a liquid crystal display element according to the first aspect, a transparent conductive film is formed and patterned in advance on a surface of a molding die for molding the resin substrate.
Then, molding of the transparent resin is performed using this mold,
When the molded body is released from the mold, the transparent conductive film on the surface of the mold is separated from the mold and taken into the surface of the molded body. Thus, a resin substrate with electrodes made of a transparent conductive film is manufactured.

In this case, the transparent conductive film is formed on the surface of the mold, and the film forming conditions, for example, the sputtering temperature can be set higher according to the heat resistance of the mold. Become. For this reason, a dense and uniform transparent conductive film can be obtained.

In addition, when the temperature of the transparent resin substrate is lowered from the molding temperature to room temperature during molding, or when a heat treatment process is performed in a subsequent manufacturing process, the transparent conductive material taken into the surface of the resin substrate at this time. The film is already in a subdivided state after patterning. For this reason, the thermal stress generated at the time of temperature change is dispersed by the difference in the thermal expansion coefficient between the resin substrate and the transparent conductive film. Therefore, as described above, a dense and uniform transparent conductive film can be obtained, and the occurrence of cracks in the transparent conductive film can be reduced by further dispersing the thermal stress.

In the manufacturing method according to the second aspect of the present invention, since the molding surface of the mold is smooth, the resin-coated substrate formed using this mold has the entire surface on which the transparent conductive film is formed. It becomes a smooth surface along the molding surface of the mold. That is, at the time of molding the resin substrate, the molding resin material also enters between the patterned transparent conductive films, thereby obtaining a molded body in which the surface of the resin substrate and the surface of the transparent conductive film are flush with each other.

For this reason, a step due to the thickness of the transparent conductive film does not occur on the surface. Therefore, a liquid crystal display device manufactured using this substrate has uneven color due to non-uniform cell gap.
Display unevenness does not occur, and the display performance is improved.

In the manufacturing method according to the third aspect, since the molding surface is subjected to a surface treatment for improving the releasability, it is not necessary to form the entire mold with a material having a high releasability, and the transparent conductive film is used. It is possible to select a less expensive material such as a glass plate that satisfies requirements such as heat resistance required for film formation. By performing a surface treatment on the surface with a material having a high release property, the use of expensive materials can be suppressed as much as possible, and the manufacturing cost of the entire mold can be reduced, so that the entire manufacturing Costs can be reduced.

In the manufacturing method according to the fourth aspect, when the coating layer covering the surface of the resin substrate with electrodes is, for example, an insulating film for protecting the electrodes, the insulating surface for protecting the electrodes is formed on the molding surface before the molding of the resin substrate. A film and a transparent conductive film are formed. In this case, the temperature condition at the time of forming the electrode protection insulating film is not restricted by the Tg (heat resistance) of the resin substrate material. By forming the film under a higher temperature processing condition, the electrode having sufficient film strength can be obtained. A protective insulating film can be obtained. As a result, in a liquid crystal display element manufactured using this resin substrate, the occurrence of a so-called vertical leakage defect is reduced, and the display quality is improved.

When the coating layer is, for example, an alignment film,
Before forming the resin substrate, the alignment film is formed on a molding surface in advance, and then a transparent conductive film is formed. Also in this case, as described above, the temperature condition at the time of forming the alignment film depends on the T
Since the film thickness is not limited by g, by forming a film under a higher temperature condition, a film with sufficient alignment characteristics can be formed.

Further, the selection range of the resin substrate material and the insulating film material and the alignment film material for protecting the electrodes is expanded, and it becomes possible to select a cheaper material, so that the manufacturing cost can be further reduced.

In the manufacturing method according to the fifth aspect, before forming the resin substrate, an alignment film, an insulating film for protecting electrodes, and a transparent conductive film are sequentially formed on the forming surface. For this reason,
Neither the high-temperature heat treatment process at the time of forming each of the electrode protection insulating film nor the transparent conductive film required after the formation of the resin substrate becomes necessary after the formation of the resin substrate. As a result, an inexpensive material having even lower heat resistance can be used as the resin substrate material, so that the manufacturing cost can be further reduced.

In the manufacturing method according to the sixth aspect, fine irregularities formed on the molding surface are transferred to the surface of the alignment film formed on this surface. Therefore, during the manufacturing process of the liquid crystal display element manufactured by this, the rubbing process for the alignment film becomes unnecessary, and the number of processes is reduced.
The overall manufacturing cost can be further reduced.

A seventh aspect of the present invention is manufactured by the above manufacturing method.
In the resin substrate for a liquid crystal display element described above, the conditions for forming the transparent conductive film, the insulating film for protecting the electrode, and the alignment film are not restricted by the heat resistance of the resin substrate material. An electrode pattern of the film can be obtained, and an insulating film for protecting the electrode having high film strength and an alignment film having excellent alignment characteristics are provided. Further, the flatness of the surface is maintained.

The liquid crystal display element according to claim 8, which is manufactured using such a resin substrate for a liquid crystal display element,
Since there is no color unevenness or display unevenness, and a vertical leakage defect is suppressed, display quality is improved. In addition, since the cheaper materials can be selected as the various constituent materials, the overall manufacturing cost can be reduced.

[0032]

【Example】

[Embodiment 1] A specific embodiment of a method for manufacturing a resin substrate for a liquid crystal display element according to the present invention will be described below with reference to FIGS. In FIG. 1A,
1 shows one molding die (hereinafter, referred to as an upper die) 1 incorporated in a resin substrate molding device (not shown). This upper mold 1
It consists of a flat metal plate. A surface treatment layer 2 made of a fluorine-based resin such as Teflon (trade name) is provided on the lower surface of the upper mold 1 in FIG. Is provided.

On the surface treatment layer 2 of the upper mold 1,
First, as shown in FIG. 1B, I as a transparent conductive film
A TO (Indium Tin Oxide) film 3 is formed by a magnetron sputtering method. Examples of sputtering conditions at this time are as follows: target material; ITO (In + Sn oxide sintered body); introduced gases; Ar and O ₂ ; sputtering degree; 2.0 × 10 ⁻² Torr;
6 nm / min, ITO film thickness; 200 nm, and
The sputtering temperature is 200 ° C. This sputtering temperature is 3
It is also possible to set the temperature to 00 ° C. or higher.

After that, using a YAG laser (SFL9400 manufactured by MIT Corporation), a wavelength of 532 nm was used.
The ITO film 3 is patterned into a predetermined electrode pattern by direct drawing of a laser having an energy density of 1.0 × 10 ⁷ J / m ² , and is composed of the ITO film 3 as shown in FIGS. An upper mold 1 with an electrode pattern is manufactured.

Thereafter, as shown in FIG. 2A, the upper mold 1 with the electrode pattern is assembled to face the other mold (hereinafter, referred to as a lower mold) 4 in the resin substrate molding apparatus. At this time, for example, the thickness of the resin molded body 8 described later is set to, for example,
When the thickness is 0.3 mm, the molding space 5 corresponding to the thickness of the sheet is required.
The molding positions of the upper mold 1 and the lower mold 4 are set such that the upper mold 1 and the lower mold 4 are provided between the two molds 1 and 4. The lower mold 4 is made of a smooth flat plate made of glass, and has a surface facing the molding space 5, like the upper mold 1,
For example, a surface treatment layer 7 made of a fluorine resin is provided.

By injecting and filling a resin material into the molding space 5, as shown in FIG.
Is cast molded, for example. Polyethyl methacrylate, a thermoplastic resin, was used as a molding material, and was used as a melt heated to 250 ° C. to prevent air bubbles from entering.
It is poured between the molds 1.4 preheated to 50 ° C. After the injection, it is allowed to cool slowly.

Thereafter, the molded resin substrate 8 is released from the mold by cooling and decompression. At this time, the ITO film 3 is peeled off from the surface treatment layer 2 in the upper mold 1, and FIG.
As shown in FIG. 5D, the mold is integrally released from the resin substrate 8 while being embedded in the surface of the resin substrate 8. Thus, a resin substrate 9 having a transparent electrode pattern with a smooth surface (hereinafter, referred to as an electrode-formed resin substrate) 9 is manufactured.

As shown in FIG. 2E, a top coat film 11 as an electrode protection insulating film is further provided on the surface of the electrode forming resin substrate 9 manufactured through the above steps. This film 11 is formed on the electrode forming resin substrate 9 by the IT
On the surface on which the O film 3 is formed, a silica coating ink containing Ti-Si as a main component is applied by an offset printing method or the like, and then fired to form a film.

Next, as shown in FIG. 4F, an alignment film material obtained by dissolving polyetheramide in a solvent is applied onto the top coat film 11 by an offset printing method or the like in substantially the same manner as the formation of the top coat film 11. After the application, the alignment film 12 is formed by firing. The two films 11 and 12 covering the surface of the substrate 9 are the top coat film 11
Is 50 to 150 nm in thickness, and the alignment film 12 is 10 to 10 in thickness.
It is provided at 0 nm.

After forming the alignment film 12 as described above, the surface of the alignment film 12 is subjected to a rubbing treatment, and then the pair of electrode forming resin substrates 9 thus obtained are bonded to each other. A liquid crystal cell is manufactured. At the time of this bonding, a thermosetting epoxy sealing material is printed on one of the electrode forming resin substrates 9 in a predetermined pattern by screen printing or the like, and the other electrode forming resin substrate 9 has a liquid crystal thickness. The plastic beads, which are spacers for securing, are sprayed so as to be uniformly dispersed. Thereafter, the liquid crystal is filled in the cell, and then sealing with a UV-curable epoxy material and pasting of a polarizing plate having a predetermined angle are sequentially performed to manufacture a liquid crystal display element.

As described above, in the method of manufacturing the resin substrate for a liquid crystal display element according to the present embodiment, the ITO film 3 was previously formed on the surface of the upper die 1 made of a smooth flat plate and patterned. Thereafter, a resin is cast to manufacture the electrode forming resin substrate 9. In this method, the resin also flows between the adjacent ITO films 3 after patterning, and as a result,
The electrode forming surface of the resin substrate 9 follows the smooth surface of the upper die 1 and is a flat surface as a whole. this is,
Even when the thickness of the ITO film 3 exceeds, for example, 200 nm, no step occurs due to the thickness. As a result, in the liquid crystal display element manufactured using the electrode-forming resin substrate 9, color unevenness and display unevenness due to non-uniform cell gap are eliminated, and display quality is improved.

On the other hand, the ITO film 3 formed on the upper mold 1 shown in FIGS.
As shown in (c) and (d), no crack is observed in the ITO film 3 in the state of being taken into the surface of the resin substrate 8. That is, the ITO film 3 is formed on the surface of the upper mold 1, and the sputtering temperature at this time may be set higher according to the heat resistance of the upper mold 1 made of metal or the surface treatment layer 2, for example. it can. In addition, when the resin material is cooled from the molding temperature to room temperature during molding of the resin substrate 8 or when the temperature is increased, the ITO film 3 taken into the surface of the resin substrate 8 is already in a finely divided state after patterning. is there.
For this reason, at the time of the above temperature change, the thermal stress generated due to the difference in the thermal expansion coefficient between the resin substrate 8 and the ITO film 3 is dispersed. Thus, a dense and uniform transparent conductive film is obtained,
In addition, since the thermal stress is dispersed, the occurrence of cracks in the ITO film 3 is reduced.

Further, as described above, the dense and uniform ITO
As a result of obtaining the film 3, it is possible to form the ITO film 3 having a small resistivity and a high transmittance.
The liquid crystal display element can be increased in size and quality.

When a transparent conductive film made of a metal oxide is formed as in the case of the ITO film 3 described above, the degree of oxidation is reduced without deteriorating the transparency of the transparent conductive film. Extensibility increases. This allows the transparent conductive film to follow the expansion or deformation of the resin substrate, thereby more reliably preventing the transparent conductive film from cracking.

Embodiment 2 Another embodiment of the present invention is described below with reference to FIGS. For convenience of explanation, members having the same functions as the members shown in the drawings of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. The same applies to other embodiments described later.

In the method of manufacturing a resin substrate for a liquid crystal display element according to the present embodiment, as shown in FIG. 3A, as in the previous embodiment, a metal smooth surface provided with a surface treatment layer 2 is provided. An upper mold 1 made of a flat plate is manufactured. In this case, the surface treatment layer 2 is formed by forming a nickel layer by sputtering.

Then, as shown in FIG. 2B, first, a top coat film 11 is formed on the surface treatment layer 2. This film 11 is manufactured by Tokyo Ohka Kogyo Co., Ltd .;
It is formed by applying a silica coating ink using a film as a raw material by an offset printing method or the like and baking at a peak of 200 ° C. for 60 minutes.

Thereafter, an ITO film 3 is formed on the top coat film 11 in the same manner as in the above embodiment (FIG. 10C).
The TO film 3 is patterned (FIG. 4D). The upper mold 1 having the ITO film 3 and the top coat film 11 thus obtained is assembled into a resin substrate molding apparatus so as to face the lower mold 4 having the surface treatment layer 7 as shown in FIG. The resin is injected into the molding space 5, and as shown in FIG.
The resin substrate 8 is molded.

Thereafter, when the resin substrate 8 is released from the mold, the surface of the resin substrate 8 having the ITO film 3 embedded in the surface is further covered with a top coat film 11, as shown in FIG. The resin substrate 9 is manufactured.

The electrode forming resin substrate 9 manufactured as described above is thereafter further covered with an alignment film 12, as shown in FIG. 4D, and the alignment film 12 is subjected to a rubbing treatment. Thereafter, as in the above embodiment, a liquid crystal is filled in a liquid crystal cell manufactured by bonding the pair of electrode-forming resin substrates 9 to each other, and a liquid crystal display element is manufactured.

In this embodiment, since the top coat film 11 is further provided on the surface of the upper mold 1 before molding the resin, the firing temperature at the time of film formation is not limited to the heat resistant temperature of the resin substrate. This can be performed at a temperature higher than the glass transition temperature (Tg) of the material. Therefore, the top coat film 11 having sufficient film strength can be obtained. As a result, in a liquid crystal display element manufactured using such an electrode-forming resin substrate 9, so-called vertical leakage defects are reduced. Also,
An inexpensive top coat film forming material requiring a heat treatment of Tg or more can be used, and the manufacturing cost can be reduced.

Further, since the top coat film 11 is formed before the resin substrate 8 is formed, it is not necessary to use a resin having high heat resistance of 120 ° C. or more as the resin substrate material, and the selection range is wide. Become. For this reason, it is possible to use an inexpensive resin material having low heat resistance, and thus it is possible to further reduce the manufacturing cost.

Embodiment 3 Still another embodiment of the present invention will be described below with reference to FIGS.

In the method of manufacturing a resin substrate for a liquid crystal display element according to the present embodiment, the alignment film 12 and the ITO film 3 are formed on the upper mold 1 before the resin substrate 8 is formed. That is, as shown in FIG. 5A, an upper mold 1 made of glass having a surface treatment layer 2 made of a nickel film is manufactured in substantially the same manner as in the second embodiment. As shown in FIG. 2B, an alignment film 12 is formed. This alignment film 12
The aromatic polyamide, for example, an alignment film material dissolved in a solvent polyether amide, for example, offset printing,
It is formed by baking at 170 ° C. peak for 90 minutes.

Thereafter, an ITO film 3 is formed on the alignment film 12 (FIG. 3C), and the ITO film 3 is patterned (FIG. 3D). The upper mold 1 with the ITO film 3 and the alignment film 12 thus obtained is incorporated in a resin substrate molding apparatus so as to face the lower mold 4 having the surface treatment layer 7, as shown in FIG. The resin is injected into the molding space 5,
As shown in FIG. 2B, the resin substrate 8 is formed.

Thereafter, when the resin substrate 8 is released, as shown in FIG. 3C, the surface of the resin substrate 8 having the ITO film 3 embedded therein is covered with an alignment film 12. 9 is produced.

The electrode-forming resin substrate 9 with the alignment film is then subjected to a rubbing treatment, and then liquid crystal is sealed between the pair of electrode-forming resin substrates 9 as in the above-described embodiments. Thus, a liquid crystal display device is manufactured.

In this embodiment, since the alignment film 12 is formed on the upper mold 1 before the molding of the resin substrate material, the upper mold 1 is made of a material having high heat resistance. The firing temperature at the time of film formation is not limited to the heat-resistant temperature of the resin substrate 8,
This can be performed at Tg or more. Therefore, sufficient alignment characteristics can be obtained, and an alignment film material requiring a heat treatment of Tg or more can be used. As a result, a stable alignment tilt angle can be obtained with an inexpensive alignment film that requires a heat treatment of Tg or more. Further, since the alignment film 12 is formed before the resin substrate 8 is formed, also in this case, it is possible to select an inexpensive resin having low heat resistance as the resin substrate material, thereby reducing the manufacturing cost. It becomes possible to reduce.

[Embodiment 4] Still another embodiment of the present invention will be described below with reference to FIGS.

In the method of manufacturing a resin substrate for a liquid crystal display element according to the present embodiment, before forming the resin substrate 8, the alignment film 12, the top coat film 11, and the ITO film 3 are sequentially formed on the upper mold 1. . In other words, as shown in FIG. 7A, a glass upper mold 1 having a surface treatment layer 2 made of a nickel layer is manufactured in substantially the same manner as in the second embodiment. As shown in FIG. 2B, an alignment film 12 and a top coat film 11 are sequentially formed under the same conditions as in the above-described embodiment. Then, top coat film 1
1, an ITO film 3 is formed (FIG. 3 (c)).
The film 3 is patterned (FIG. 2D).

The upper die 1 with the ITO film 3, the top coat film 11, and the alignment film 12 thus obtained is provided with the surface treatment layer 7, as shown in FIG. The resin substrate 8 is assembled into the resin substrate molding apparatus so as to face the lower mold 4, and the resin is injected into the molding space 5 to form the resin substrate 8 as shown in FIG.

Thereafter, when the resin substrate 8 is released from the mold, as shown in FIG. 3C, the top coat film 11 and the alignment film 12 are further formed on the surface of the resin substrate 8 in which the ITO film 3 is embedded. The electrode forming resin substrates 9 sequentially laminated are manufactured.

The electrode-forming resin substrate 9 is then subjected to a rubbing treatment in the same manner as in the third embodiment, and then liquid crystal is sealed between the pair of electrode-forming resin substrates 9 to form a liquid crystal display device. Is done.

In this embodiment, the top coat film 11 and the alignment film 12 are provided on the surface of the resin substrate 8 at the same time as the resin substrate 8 is formed. Since the high-temperature heat treatment process at the time of forming each film with the alignment film is eliminated, an inexpensive material with lower heat resistance can be used as the resin substrate material.

[Embodiment 5] Still another embodiment of the present invention will be described below with reference to FIGS.

In the method of manufacturing a resin substrate for a liquid crystal display element according to the present embodiment, as shown in FIG. 9A, predetermined irregularities 1a are formed on the surface of an upper mold 1 made of a flat plate made of glass. I have. The unevenness 1a is formed as a repetitive shape of a slope aligned in one direction, for example, a saw-tooth shape, the angle of the slope is about 10 °, the interval between the ridge lines of the slope is about 1 μm, and the step of the slope is about 0 °. .2 μm.

The surface of the upper mold 1 on which the irregularities 1a are formed is coated with nickel by sputtering to provide a surface treatment layer 2. In the surface treatment layer 2, the above-mentioned uneven shape on the surface of the upper mold 1 is exposed as it is.

On the surface treatment layer 2 in the upper mold 1,
As shown in FIG. 3B, similarly to the above-described embodiment, the alignment film 12 is formed.
And a top coat film 11 are sequentially formed, and an ITO film 3 is formed as shown in FIG.
The O film 3 is patterned (FIG. 4D).

The upper mold 1 with the ITO film 3, the top coat film 11, and the alignment film 12 thus obtained is provided with a surface treatment layer 7 as shown in FIG. Is installed in the resin substrate molding apparatus so as to face the lower mold 4,
As shown in FIG. 2B, the resin substrate 8 is molded.

After that, when the resin substrate 8 is released, as shown in FIG. 4C, the top coat film 11 and the alignment film 12 are further formed on the surface of the resin substrate 8 in which the ITO film 3 is embedded. The electrode forming resin substrates 9 sequentially laminated are manufactured. In the electrode forming resin substrate 9, irregularities formed in advance on the upper mold 1 are transferred to the surface of the alignment film 12 serving as a surface layer,
This functions to orient the liquid crystal at a predetermined tilt angle.

Therefore, when the liquid crystal is sealed with the pair of electrode forming resin substrates 9 opposed to each other and a liquid crystal display element is manufactured, a rubbing process for aligning the liquid crystal is not required. Since the number of processes is reduced by one,
Overall manufacturing costs are reduced.

In each of the above embodiments, an example is shown in which the surface treatment layer 2 made of a fluorine-based resin or nickel is provided on the surface of the upper mold 1. However, the surface treatment layer 2 may be made of, for example, tantalum or gold. It is also possible to form with a thin film. The ITO film 3 was formed by magnetron sputtering.
It is also possible to form a film by a VD method or the like, and the patterning of the formed ITO film 3 can also be performed by a dry etching method or a wet etching method instead of the above-described direct drawing by a laser beam. Further, a conductive polymer may be used as the transparent conductive film instead of the ITO film 3 and formed by printing, spin coating, dipping, or the like.

On the other hand, as a molding material for molding the resin substrate 8, a thermoplastic resin other than the polyethyl methacrylate mentioned in the above examples, for example, polycarbonate, polyarylate, polymethyl methacrylate, polyethylene terephthalate, polyether sulfone It is also possible to use these materials, and it is also possible to form them by injection molding using these materials. Further, as molding materials, alkyl methacrylates represented by methyl methacrylate, bifunctional methacrylates, alkyl acrylates represented by methyl acrylate, bifunctional acrylates, styrene, divinylbenzene, epoxy methacrylate, various epoxy monomers, these resins The monomer alone and the mixture can be cross-linked and polymerized by heating, pressurizing, and UV irradiation together with the polymerization initiator to form a molded product.

Further, on the upper mold 1 after the ITO film 3 is formed and patterned, a switching element such as a color filter and a TFT element, or a gas barrier film is further formed on the surface thereof. It is also possible to incorporate the mold 1 into a resin substrate molding apparatus and to mold and mold the resin substrate 8.

[0075]

As described above, in the method for manufacturing a resin substrate for a liquid crystal display element according to the first aspect of the present invention, a pair of molding dies are set at opposing molding positions with a predetermined molding space interposed therebetween.
In the method for manufacturing a resin substrate for a liquid crystal display element, which forms a resin substrate by filling the molding space with a transparent resin, a transparent conductive film is formed on a molding surface facing the molding space in one molding die. After patterning the transparent conductive film into a predetermined electrode pattern, the molding die is set at the molding position, the transparent resin is filled in the molding space, and then the molded body made of the transparent resin is separated from the molding surface together with the transparent conductive film. Thus, a resin substrate with electrodes is manufactured.

Thus, the conditions for forming the transparent conductive film can be set higher according to the heat resistance of the mold, and a dense and uniform transparent conductive film can be obtained. In addition, after the resin substrate is formed, since the transparent conductive film is already in a finely divided state after patterning, thermal stress due to a difference in thermal expansion coefficient between the resin substrate and the transparent conductive film is dispersed. As a result, there is an effect that generation of cracks in the transparent conductive film can be reduced.

A method of manufacturing a resin substrate for a liquid crystal display element according to a second aspect is such that the molding surface is formed as a smooth surface, and the transparent conductive film is formed on the smooth surface.

As a result, the entire surface of the resin substrate with electrodes is formed as a smooth surface, and no step corresponding to the thickness of the electrodes is formed on the surface. The element does not cause color unevenness and display unevenness due to non-uniform cell gap, and as a result, it has an effect that display performance of the liquid crystal display element can be improved.

A third aspect of the present invention is a method of manufacturing a resin substrate for a liquid crystal display element, wherein the molding surface is subjected to a surface treatment for enhancing releasability, and the transparent conductive film is formed on the treated surface. .

Thus, it is not necessary to form the entire mold with a material having high mold release properties, and a less expensive material such as a glass plate can be selected. By performing a surface treatment on the surface with a material having a high release property, the use of expensive materials can be suppressed as much as possible, and the manufacturing cost of the entire mold can be reduced, so that the entire manufacturing There is an effect that it is possible to reduce costs.

According to a fourth aspect of the present invention, in the method of manufacturing a resin substrate for a liquid crystal display element, a coating layer provided to cover the surface of the resin substrate with electrodes is previously formed on the molding surface, and then the transparent conductive film is formed. After the patterning and the molding of the transparent resin are sequentially performed, the molded body is separated from the molding surface together with the coating layer and the transparent conductive film.

Thus, in the case where, for example, an insulating film for protecting an electrode is provided as a coating layer, an insulating film for protecting an electrode having a sufficient film strength can be obtained by forming the film under a higher temperature processing condition. . As a result, in a liquid crystal display element manufactured using this resin substrate, the occurrence of a so-called vertical leakage defect is reduced, and the display quality is improved.
In the case where an alignment film is provided as the coating layer, a film with sufficient alignment characteristics can be formed. further,
Since the selection range of each material is widened and a cheaper material can be selected, there is an effect that the manufacturing cost can be reduced.

According to a fifth aspect of the present invention, in the method of manufacturing a resin substrate for a liquid crystal display element, the coating layer is formed of a laminate of an alignment film and an electrode protection insulating film formed sequentially on a molding surface.

Thus, after forming the resin substrate, it is not necessary to perform any of the high-temperature heat treatment processes at the time of forming the insulating film for protecting the electrode and the transparent conductive film. This makes it possible to use a simple material, thereby producing an effect that the manufacturing cost can be further reduced.

A method of manufacturing a resin substrate for a liquid crystal display element according to a sixth aspect of the invention has a structure in which fine irregularities for orienting liquid crystals are formed on the molding surface on which the alignment film is formed.

As a result, during the manufacturing process of the liquid crystal display element,
Since the rubbing process for the alignment film is not required, there is an effect that the overall manufacturing cost can be further reduced.

Therefore, the resin substrate for a liquid crystal display element according to claim 7, which is manufactured by the above-described manufacturing method, has a crack-free dense and uniform transparent conductive film electrode pattern, and has a high film strength. It has an insulating film for use and an alignment film having excellent alignment characteristics, and further has features such as maintaining the flatness of the surface. Therefore, the liquid crystal display element according to claim 8, which is manufactured using such a resin substrate for a liquid crystal display element, has no color unevenness or display unevenness, has good display performance, and is inexpensive as various materials. By being able to select one, the overall manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a view showing a manufacturing process of a resin substrate for a liquid crystal display element according to an embodiment of the present invention.
(C) is a schematic cross-sectional view showing a processing step of an upper mold incorporated in the resin substrate molding apparatus, and (d) is a sectional view of FIG.
FIG.

2A and 2B show a step that follows the manufacturing step of FIG. 1; FIG. 2A is a schematic cross-sectional view of a main part of a resin substrate molding apparatus incorporating the above upper die, and FIG. FIG. 4 is a schematic cross-sectional view of a main part showing a molding state of the resin substrate in the resin substrate molding apparatus, and FIGS. 4C, 4E, and 4F are schematic cross-sectional views showing the subsequent processing steps of the resin substrate molded above. FIG. 3D is a schematic plan view of FIG.

3 (a) to 3 (f) show a process of manufacturing a resin substrate for a liquid crystal display element according to another embodiment of the present invention.
(D) is a schematic cross-sectional view showing the processing steps of the upper mold incorporated in the resin substrate molding apparatus.

FIG. 4 shows a step that follows the manufacturing step of FIG. 3; FIG. 4 (a) is a schematic cross-sectional view of a main part of a resin substrate molding apparatus incorporating the above upper die, and FIG. FIGS. 3C and 3D are schematic cross-sectional views showing the subsequent processing steps of the resin substrate formed as described above, showing the molding state of the resin substrate in the resin substrate molding apparatus. FIGS.

5 (a) to 5 (d) show a manufacturing process of a resin substrate for a liquid crystal display element according to still another embodiment of the present invention. FIGS. It is a cross-sectional schematic diagram which shows the processing process of.

FIG. 6 shows a step that follows the manufacturing step of FIG. 5, wherein FIG. 6 (a) is a schematic cross-sectional view of a main part of a resin substrate molding apparatus incorporating the upper die, and FIG. FIG. 3 is a schematic cross-sectional view of a main part showing a molding state of the resin substrate in the resin substrate molding apparatus, and FIG. 3C is a schematic cross-sectional view showing the resin substrate molded as described above.

FIGS. 7A to 7D show a process for manufacturing a resin substrate for a liquid crystal display element according to still another embodiment of the present invention. FIGS. It is a cross-sectional schematic diagram which shows the processing process of.

8A and 8B show a step that follows the manufacturing step of FIG. 7; FIG. 8A is a schematic cross-sectional view of a main part of a resin substrate molding apparatus incorporating the upper die, and FIG. FIG. 3 is a schematic cross-sectional view of a main part showing a molding state of the resin substrate in the resin substrate molding apparatus, and FIG. 3C is a schematic cross-sectional view showing the resin substrate molded as described above.

9 (a) to 9 (d) show a manufacturing process of a resin substrate for a liquid crystal display element according to still another embodiment of the present invention. It is a cross-sectional schematic diagram which shows the processing process of.

10 shows a step that follows the manufacturing step of FIG. 9, wherein FIG. 10 (a) is a schematic cross-sectional view of a main part of a resin substrate molding apparatus incorporating the above upper mold, and FIG. FIG. 4 is a schematic cross-sectional view of a main part showing a molding state of the resin substrate in the resin substrate molding apparatus, and FIG.

11 (a) to 11 (e) are cross-sectional schematic views of a transparent resin substrate sequentially formed along the manufacturing process, showing a conventional manufacturing process of the resin substrate.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Upper die (molding die) 1a Unevenness 2 Surface treatment layer 3 ITO film (transparent conductive film) 4 Lower die (molding die) 5 Molding space 6 Side wall 7 Surface treatment layer 8 Resin substrate 9 Electrode forming resin substrate 11 Top coat film ( Insulating film for electrode protection) 12 Alignment film

Claims (8)

(57) [Claims] 1. Production of a resin substrate for a liquid crystal display element in which a pair of molding dies are set at molding positions opposed to each other across a predetermined molding space, and the molding space is filled with a transparent resin to form a resin substrate. In the method, a transparent conductive film is formed on a molding surface facing the molding space in one molding die, and after patterning this transparent conductive film into a predetermined electrode pattern, the molding die is set at a molding position and is transparent. Manufacturing a resin substrate with an electrode by filling a resin into a molding space and then peeling the molded body made of the transparent resin from a molding surface together with a transparent conductive film to produce a resin substrate with electrodes; Method. 2. The method according to claim 1, wherein the molding surface is formed as a smooth surface, and the transparent conductive film is formed on the smooth surface. 3. The resin for a liquid crystal display element according to claim 1, wherein the molding surface is subjected to a surface treatment for enhancing releasability, and the transparent conductive film is formed on the treated surface. Substrate manufacturing method. 4. A coating layer provided to cover the surface of the resin substrate with electrodes is previously formed on the molding surface, and thereafter, the film formation and patterning of the transparent conductive film and the molding of the transparent resin are sequentially performed. And releasing the molded body from the molding surface together with the coating layer and the transparent conductive film.
Or a method for producing a resin substrate for a liquid crystal display element according to item 3. 5. The production of a resin substrate for a liquid crystal display device according to claim 4, wherein said coating layer comprises a laminate of an orientation film and an insulating film for protecting electrodes sequentially formed on a molding surface. Method. 6. The method for manufacturing a resin substrate for a liquid crystal display element according to claim 5, wherein fine irregularities for aligning the liquid crystal are formed on the molding surface on which the alignment film is formed. 7. A resin substrate for a liquid crystal display element manufactured by the manufacturing method according to claim 1. 8. A liquid crystal display device comprising a pair of substrates, at least one of which is formed of the resin substrate for a liquid crystal display device according to claim 7, opposed to each other, and a liquid crystal is sealed between these substrates.