JP2003140144A - Method for manufacturing scattering reflection substrate and reflective liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a scattering reflection substrate provided with excellent reflection characteristics with a convenient method, and to provide a bright reflective liquid crystal display device with high chroma including the scattering reflection substrate. SOLUTION: The method for manufacturing the scattering reflection substrate is provided with a step to form a resin layer 23 on an insulating substrate 11, a step to dispose a reflection layer 19 on the resin layer 23 and a step to form projecting and recessing parts on the surface of the reflection layer 19 by heating the insulating substrate 11 equipped with the resin layer 23 and the reflection layer 19 or a step to form an inorganic insulation film on the reflection layer 19 with a sputtering method and simultaneously to form projecting and recessing parts on the surface of the reflection layer 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a scattering / reflection substrate that scatters and reflects external light, and a method of manufacturing a reflective liquid crystal display device using the scattering / reflection substrate.

[0002]

2. Description of the Related Art A reflection type liquid crystal display device is a liquid crystal display device which uses natural light as a light source and does not require a light source such as a backlight, and includes a liquid crystal layer, a pair of insulating substrates sandwiching the liquid crystal layer, and a metal reflector. Composed of and. The conventional twisted nematic (TN) method or the super twisted nematic (STN) method requires two polarizing plates, so that natural light passing through the two polarizing plates loses 3/4 of that. And the display becomes dark. Further, since the position of the metal reflection plate must be arranged outside the polarizing plate, that is, outside the insulating substrate, when light is obliquely incident on the reflection type liquid crystal display device, it is recognized as an image. There has been a problem that reflected light is reflected twice on the liquid crystal layer side surface of one insulating substrate and the metal reflective film surface. In addition, since the pixel through which the incident light passes and the pixel through which the reflected light passes are different from each other, when the contrast is lowered or color display is performed by using a color filter, color mixture is caused and color reproducibility is deteriorated. The phenomenon was happening.

In order to solve these problems, the polarizing plate 1
A TN method or STN method capable of displaying on a single sheet, a phase transition type guest-host method capable of displaying without using a polarizing plate, and the like have been proposed. In any case, since the number of polarizing plates can be reduced, the display can be brightened. In addition, the reflector is the liquid crystal layer side of one insulating substrate,
That is, since it can be provided inside the liquid crystal cell, it is possible to solve the above-mentioned problem of double reflection, reduction in contrast, and color mixture of color filters.

However, in the conventional reflection type liquid crystal display device in which the internal reflection plate, which is the reflection layer provided inside the liquid crystal cell, is a mirror surface, the specular reflection direction of incident light is bright, but at other angles it becomes abruptly dark, The viewing angle characteristics are very poor. Therefore, in order to improve the viewing angle characteristics, there has been proposed a scattering reflection substrate in which a fine uneven reflection surface is formed on an internal reflection plate to impart scattering properties.

As a scattering / reflecting substrate having such a concavo-convex reflecting surface, generally, a photosensitive resin is placed on an insulating substrate, and the photosensitive resin is exposed to light by means of photolithography or the like, and an unexposed area is exposed. After forming a fine uneven pattern on the surface of the photosensitive resin by utilizing the difference in dissolution with a developing solution,
Means for forming a metal film such as aluminum having excellent reflection characteristics on the surface thereof has been devised. However, the method using the photolithography means has a problem that the manufacturing process becomes complicated and the manufacturing cost becomes high.

[0006]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing a scattering reflection substrate having good reflection characteristics by a simple method. Another object of the present invention is to provide a bright, high-saturation reflective liquid crystal display device that incorporates this scattering / reflecting substrate.

[0007]

The scattering reflection substrate of the present invention comprises a step of forming a resin layer on an insulating substrate, a step of providing a reflection layer on the resin layer, a resin layer and the reflection layer. And heating the insulating substrate provided to form irregularities on the surface of the reflective layer.

Alternatively, the scattering reflection substrate of the present invention comprises a step of forming a resin layer on an insulating substrate, a step of providing a reflection layer on the resin layer, and a method of sputtering an inorganic insulating film on the reflection layer. And the step of forming irregularities on the surface of the reflective layer at the same time.
Also, after the step of forming irregularities on the surface of this reflective layer,
It is preferable to have a step of heating an insulating substrate provided with a resin layer, a reflective layer, and an inorganic insulating film.

The resin layer used in this step is preferably transparent at least in the visible light region.
It is preferable that the film thickness is from 5 μm to 5 μm.

The reflecting layer used in this step is characterized by being formed of a metal reflecting film, and the metal reflecting film is preferably made of aluminum or aluminum alloy.
The inorganic insulating film used in this step is preferably a silicon oxide film.

Further, in the method of manufacturing a reflection type liquid crystal display device of the present invention, a step of forming a resin layer on at least one insulating substrate of a pair of insulating substrates, and providing a reflecting layer on the resin layer. And a step of heating an insulating substrate having a resin layer and a reflective layer to form irregularities on the surface of the reflective layer, an insulating substrate having irregularities formed on the surface of the reflective layer, and the other insulating substrate It is characterized by having a step of enclosing a liquid crystal between and.

Alternatively, in the method of manufacturing a reflective liquid crystal display device of the present invention, a step of forming a resin layer on at least one insulating substrate of a pair of insulating substrates, and a reflective layer on the resin layer. The method is characterized by including a step of providing and a step of forming an inorganic insulating film on the reflective layer by a sputtering method and at the same time forming irregularities on the surface of the reflective layer.

Further, as a method of manufacturing the reflective liquid crystal display device of the present invention, a step of heating an insulating substrate having a resin layer, a reflective layer and an inorganic insulating film after the step of forming irregularities on the surface of the reflective layer. May be provided.

Further, the method of manufacturing the reflection type liquid crystal display device of the present invention comprises a color filter forming step of forming a color filter layer after the step of forming irregularities on the surface of the reflecting layer, and an overcoat on the color filter layer. Overcoat layer forming step of forming a layer, an electrode forming step of forming an electrode on the overcoat layer, an alignment film setting step of setting an alignment film subjected to an alignment treatment on the electrode, and another insulating substrate An electrode forming step of forming an electrode on the other side, an alignment film setting step of setting an alignment-treated alignment film on the electrode of the other insulating substrate, and one insulating substrate and the other insulating substrate are bonded by a sealing material. It is characterized by having a matching step.

[Operation] The scattering reflection substrate manufactured by the manufacturing method of the present invention comprises a first substrate made of an insulating substrate,
It has a transparent resin layer that is cured by heat or light, and a reflective layer having an uneven reflective surface on the surface. The uneven reflection surface is formed by the internal stress difference between the resin layer and the reflection layer. As a method of generating an internal stress difference, a method of utilizing internal stress generated inside the reflective layer during formation of the reflective layer on the resin layer and during formation of the inorganic insulating film in the reflective layer, resin layer and reflective layer A method of utilizing internal stress generated by heat treatment due to a difference in thermal expansion coefficient between the two, utilizing internal stress generated inside the reflective layer during film formation of the reflective layer and internal stress generated by heat treatment There is a way. In either method, the surface of the reflective layer on the resin layer is deformed in the process of relaxing the generated internal stress difference, and an uneven reflective surface is formed on the surface of the reflective layer.

By such a method, it is possible to form a scattering reflection substrate having good reflection characteristics, and it is possible to realize a bright reflection type liquid crystal display device with a small parallax. Furthermore, different reflection characteristics can be obtained by the respective methods, and the reflection type liquid crystal display device can be used properly according to the application.

Further, the scattering reflection substrate can be formed by a simple process such as coating a resin layer, forming a reflection layer, and heat treatment. In addition, the uneven shape of the uneven reflection surface that controls the collection and reflection angle of external light is the thickness (volume) of the transparent resin layer.
By controlling the temperature of heat treatment during the heat treatment of transparent resin, it is possible to change and control the degree of curing of the resin, and it is possible to optimize the amount of resin deformation caused by internal stress. Is.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the scattering reflection substrate and the reflection type liquid crystal display device according to the present invention will be described below with reference to the drawings.

[First Embodiment: FIG. 1, FIG. 2, FIG. 3, FIG. 4 and FIG. 5] FIG. 1C is a sectional view showing a scattering reflection substrate 41 in the present embodiment. As shown in FIG. 1 (c),
The scattering / reflecting substrate 41 includes a resin layer 23 and a reflecting layer 19 on the first substrate 11 made of a transparent insulating glass substrate, and the reflecting layer 19 has an uneven reflecting surface 39 on its surface.

The reflection layer 19 is composed of a metal reflection film made of an aluminum film, and is a metal reflection film (reflection layer 19).
Has a thickness of about 10 nm to 200 nm. When the film thickness is 10 nm to 100 nm, the metal reflection film (reflection layer 19) functions as a semi-transmission film, and has a function of transmitting half of the light and reflecting half of the light. The resin layer 23 is formed of a transparent resin material that is cured by light and heat, and has a film thickness of about 1.0 μm to 5.0 μm.

The uneven reflection surface 39 of FIG. 1C is formed in an irregular pattern, and the unevenness of the unevenness is 0.1 μm.
To 1.0 μm, and the average distance between convex portions is 4 μm
m to about 10 μm.

Next, a manufacturing method for forming the structure of the scattering reflection substrate in this embodiment shown in FIG. 1C will be described with reference to FIGS. 1A to 1C. Figure 1
As shown in (a), first, as a heat or photocurable transparent resin layer 23 on the first substrate 11 made of an insulating glass substrate, for example, a photocurable resin manufactured by Nippon Steel Chemical Co., Ltd. Resin solution, V259PR-0 with viscosity of 15 cps
17X is placed on the first substrate by spin coating,
Next, it was baked for 2 minutes on a hot plate heated to 90 ° C. to form a resin layer 23 on the first substrate 11 with a film thickness of 3.5 μm.

Next, as shown in FIG. 1B, the first
After heat-treating the substrate 11 of No. 2 in a clean oven at 220 ° C. for 60 minutes, an aluminum film having a thickness of 130 nm is formed as a metal reflection film of a reflection layer on the transparent resin layer 23 by a sputtering method, and the reflection is performed. Form layer 19. Although the aluminum film is used as the metal reflection film in the present embodiment, an aluminum alloy may be used. As the reflective layer, other than the aluminum film or aluminum alloy, any metal film having good reflectivity can be used.

Next, the first substrate 11 is heat-treated at 220 ° C. for 1 hour in a clean oven to generate internal stress due to the difference in thermal expansion coefficient between the resin layer 23 and the metal reflection film 19, and the inside In the process of relaxing the stress, the surface of the resin layer 23 on the metal reflection film (reflection layer 19) side is deformed,
As shown in FIG. 1C, the surface of the metal reflective film (reflective layer 19) forms irregularities on the surface of the metal reflective film (reflective layer 19) to form an irregular reflective surface 39. The heating temperature is 14
A temperature of 0 ° C. to 250 ° C. can be adopted. Since the reflection characteristics of the unevenness of the surface change depending on the heating temperature, the optimum heating temperature is selected depending on the resin layer or the reflection layer used. The scattering reflection substrate 41 is formed as described above.

Next, FIG. 2 shows the results of measuring the reflection characteristics of the formed scattering reflection substrate 41. As shown in FIG. 3, the reflection characteristic was measured by setting the scattering reflection substrate 41 as the sample 47 to be measured so that the uneven reflection surface 39 faces upward. The light source 43 is arranged so that the incident angle α of the incident light with respect to the normal direction of the sample 47 to be measured is −30 degrees, and the luminance meter 45 is a luminance meter centered on the point where the incident light is irradiated. 45 was arranged so as to rotate, and the luminance meter 45 was rotated so that the reflection angle β of the reflected light was changed and the change in reflectance was measured. The reflection angle β was set to -10 degrees to 70 degrees. Regarding the reflectance, the reflectance of the standard white plate measured in advance by the same method was set as 100, and the reflectance was expressed as a relative ratio to the reflectance of the standard white plate.

In FIG. 2, the horizontal axis shows the reflection angle β, and the vertical axis shows the relative reflectance with respect to the reflectance of the standard white plate. It can be said that if the reflectance on the vertical axis is high, the orthogonal reflectance is high, and if the range of the reflection angle on the horizontal axis is wide, the scattering property is high. The characteristic of the scattering reflector manufactured in the present embodiment is shown by a curve a in FIG. As shown by the curve a in FIG. 2, the reflection characteristic of the scattering reflection substrate 41 of the present embodiment exceeds 100% when the reflection angle is 15 degrees to 45 degrees, and the center of the regular reflection angle is 30 degrees. As a result, a sufficiently high reflectance could be obtained within a range of ± 15 degrees.

As described above, it was possible to manufacture a bright scattering / reflecting substrate having good reflection characteristics, having a small parallax. Further, unlike the conventional method, a photolithography process is not required, and the scattering reflection substrate is formed by simple steps such as a coating step of the resin layer 23, a film forming step of the metal reflection film (reflection layer 19), and a heat treatment step. Could be formed.

Next, a reflection type liquid crystal display device using the scattering reflection substrate of this embodiment will be described. FIG. 4 is a cross-sectional view showing the manufacturing process of the reflective liquid crystal display device in this embodiment. Hereinafter, description will be given with reference to FIG. As shown in FIG. 4, the reflective liquid crystal display device of the present embodiment has a liquid crystal layer 2
1, a lower substrate 29 and an upper substrate 31 facing each other so as to sandwich the liquid crystal layer 21, a sealing material (not shown) for sealing the liquid crystal layer 21, and a liquid crystal layer 21 opposite to the upper substrate 31. And a polarizing plate 27 provided on the side (outside). The structures of the lower substrate 29 and the upper substrate 31 will be described below.

The lower substrate 29 includes a scattering / reflecting substrate 41, a color filter layer 33, an overcoat layer 35 formed to cover the color filter layer 33, a first electrode 15, and a first electrode 15. It is composed of an alignment film (not shown) formed so as to cover it, and a lead electrode (not shown) connected to the first electrode 15. The scattering reflection substrate 41 is the scattering reflection substrate 41 shown in FIG.
Is used.

The color filter layers 33 are red,
Using a color resist in which pigments adjusted in blue and green are dispersed in a photosensitive resin, a red filter R, a blue filter B, and a green filter G each having a thickness of 0.5 μm are used. It is possible.

On the color filter layer 33, an acrylic thermosetting resin is used for the purpose of flattening the surface irregularities generated in the process of forming the color filter layer 33 and for protecting the color filter surface. Consisting of 3.
An overcoat layer 35 of 0 μm is provided. further,
A first electrode 15 made of an indium tin oxide film is provided on the overcoat layer 35 for the purpose of applying a voltage to the liquid crystal to drive the liquid crystal display device.

The upper substrate 31 is a second substrate 13 made of a transparent insulating glass substrate and a second electrode 17 made of an indium tin oxide film provided on the second substrate 13.
It is composed of an alignment film (not shown) formed so as to cover the second electrode 17, and a lead electrode (not shown) connected to the second electrode 17.

The lower substrate 29 and the upper substrate 31 configured as described above face each other so that the first electrode 15 and the second electrode 17 face each other and their stripe patterns are orthogonal to each other. Are arranged. Then, a pixel is formed at a portion where the stripe pattern of the first electrode 15 and the stripe pattern of the second electrode 17 intersect, and in each pixel, the first electrode 15 and the first electrode 15 are connected from the driving power source through the extraction electrode. The liquid crystal layer 21 is driven and phase-modulated by an arbitrary voltage applied between the liquid crystal layer 21 and the second electrode 17. The combination of the phase modulation amount in the liquid crystal layer 21 and the deflecting action in the polarizing plate 27 switches the emission of the light reflected by the concave-convex reflecting surface 39 to display black and white. In the present embodiment, a normally black type that can obtain white display when no voltage is applied is used. Then, an arbitrary image is represented by the plurality of pixels.

Next, a manufacturing method for forming the structure of the reflective liquid crystal display device according to this embodiment will be described with reference to FIG. The method for manufacturing the scattering / reflecting substrate 41 is shown in FIG.
It was manufactured by the previous manufacturing method illustrated in FIGS.

Next, the uneven reflection surface 39 of the scattering reflection substrate 41
A red filter base material in which a red pigment is dispersed in a photosensitive resin, for example, a photosensitive color ink material V2302R manufactured by Nippon Steel Chemical Co., Ltd. is applied by a spin coating method to a film thickness of 0.57 μm, Baking was performed for 2 minutes on a hot plate heated to 90 degrees.

Next, using an exposure device using a high-pressure mercury lamp as a light source, a portion where the red filter R is to be formed is exposed through a photomask with an exposure amount of 200 mJ / cm ² , and then, a value of 0.
Development was carried out for 1 minute with a developer of 01w% sodium carbonate, and a red filter R was obtained in a portion which was insoluble in the developer. After that, similarly, in the order of blue and green, the blue filter B
And a green filter G are formed in a pattern shape, and a color filter forming step of forming the color filter layer 33 on the uneven reflection surface 39 is performed.

Next, as a transparent overcoat layer 35, an Optomer SS6777 (trade name) manufactured by JSR is formed on these color filter layers 33 by a spin coating method with a film thickness of 3.0 μm. Furthermore, from 220 degrees to 240
The overcoat layer 35 is heat-cured for 2 hours in a temperature range of 100 degrees Celsius, and at the same time, unreacted substances not involved in the heat-curing are gasified and removed. In this way, the overcoat forming step of forming the overcoat layer is performed. The overcoat layer 35 plays a role of improving chemical resistance, sputtering resistance and flatness of the color filter layer 33.

Next, a transparent conductive film made of an indium tin oxide film is formed with a film thickness of 110 nm by a sputtering method. Next, a positive photoresist is applied to the entire surface of the indium tin oxide film by a spin coating method, and a photolithography process is performed by an exposure process and a development process using a photomask. It is formed in a pattern shape. Then, using the photoresist as an etching mask, patterning is performed to form a first pattern.
The electrode forming step of forming the electrode 15 of FIG. The etching treatment of the indium tin oxide film is performed by a wet etching treatment using a mixed solution of ferric chloride and hydrochloric acid.
After that, the photoresist used as the etching mask was replaced with a resist stripper, for example, N-320 manufactured by Nagase & Co.
It is removed by a wet peeling method using (trade name).

Further, an alignment film (not shown) is formed so as to cover the first electrode 15, and the lower substrate 29 is prepared through an alignment film installation step of performing an alignment treatment.

Next, the upper substrate 31 will be described. Similarly to the lower substrate 29, a transparent conductive film made of an indium tin oxide film is provided on the upper substrate 31 and the glass substrate 13.
A film having a thickness of 110 nm is formed by a sputtering method. Next, a positive photoresist is applied to the entire surface of the indium tin oxide film by a spin coating method, and photolithography is performed by an exposure process and a development process using a photomask, and the photoresist is applied to the second electrode 17. It is formed in a pattern shape. Then, using the photoresist as an etching mask, patterning is performed to form the second electrode 1
An electrode forming step for forming 7 is performed. The etching process of the indium tin oxide film and the peeling of the photoresist are the same as those at the time of manufacturing the lower substrate 29. Further, similarly to the lower substrate 29, an upper substrate 31 is formed through an alignment film installation step of forming an alignment film (not shown) so as to cover the second electrode 17.

Next, the lower substrate 29 and the upper substrate 31 are
The first electrode 15 on the first substrate 11 and the second electrode 17 on the second substrate 13 face each other, and further, the first electrode 1
The stripe pattern 5 and the stripe pattern of the second electrode 17 are arranged so as to be orthogonal to each other. By arranging in this way, a pixel is formed at a portion where the first electrode 15 and the second electrode 17 intersect. Then, the lower substrate 29
A sealing material (not shown) is formed between the upper substrate 31 and the upper substrate 31, and a bonding process for bonding both substrates is performed. Then, as shown in FIG. 4, the liquid crystal layer 21 is enclosed between the substrates by the sealing material.

For the liquid crystal layer 21, a super twisted nematic liquid crystal having a twist orientation of 240 ° was used. A polarizing plate 27 is provided on the opposite side of the second substrate 13 from the liquid crystal layer 21.
To provide. Further, in order to prevent coloring due to the birefringence effect of the liquid crystal layer 21, between the second substrate 13 and the polarizing plate 27,
A retardation plate may be provided. The reflective liquid crystal display device is manufactured as described above.

Next, the results of measuring the reflection characteristics of the formed reflection type liquid crystal display device are shown in FIG. In addition, the measurement of the reflection characteristics was performed by the above-described measurement method of FIG. The reflective liquid crystal display device was placed at the position of the sample 47 to be measured with the polarizing plate 27 facing up. The incident angle α, the arrangement position of the luminance meter 45, and the like were the same as those when the scattering reflection substrate 41 was measured.
The reflection characteristic of the reflection type liquid crystal display device manufactured in the present embodiment is shown by a curve a in FIG. 5, and the reflection angle is 15 degrees to 4 degrees.
At 5 degrees, it exceeded 100%, and a sufficiently high reflectance could be obtained within a range of ± 15 degrees centering on the regular reflection angle of 30 degrees.

As described above, there is no need for a photolithography process as in the conventional method, and the scattering reflection is performed by a simple process such as a coating process of the resin layer 23, a film forming process of the metal reflection film 19 and a heat treatment process. Since the substrate can be formed, it is possible to realize a bright reflective liquid crystal display device having good reflection characteristics, a small parallax, and a simple process.

[Second Embodiment: FIG. 2, FIG. 5, FIG. 6, FIG. 7] FIG. 6 is a cross-sectional view showing a method of manufacturing the scattering reflection substrate 41 in the present embodiment. This will be described below with reference to FIG. As shown in FIG. 6C, the scattering reflection substrate 41 of the present embodiment has a resin layer 23, a reflection layer 19, and an inorganic insulating film 2 on a first substrate 11 made of an insulating glass substrate.
5 is provided on the surface of the reflective layer 19, and the uneven reflective surface 3
9 is provided. The reflective layer 19 is a metal reflective film made of an aluminum film, and the inorganic insulating film 25 is a silicon oxide film. The film thickness of the metal reflection film (reflection layer 19) was the same as in the first embodiment. Further, the material and film thickness of the resin layer 23 are the same as those in the first embodiment, and the uneven reflection surface 39 is used.
The uneven steps were almost the same.

Next, a manufacturing method for forming the structure of the scattering reflection substrate in this embodiment will be described with reference to FIGS.
This will be described with reference to (c). First, the same resin solution as that of the first embodiment is used as the heat or photocurable transparent resin layer 23 on the first substrate 11 which is a glass substrate of an insulating substrate, and the same method is used. A resin layer 23 having a thickness of 0.5 μm was formed.

Next, as in the first embodiment, as shown in FIG.
As shown in (b), an aluminum film was formed as a metal reflection film (reflection layer 19) by sputtering with a thickness of 130n.
The film was formed with a film thickness of m.

Subsequently, as shown in FIG. 6C, a silicon oxide film was formed as the inorganic insulating film 25 on the reflective layer 19 by sputtering to have a film thickness of 20 nm. In this film forming process, a large internal stress is generated in the inorganic insulating film 25 made of a silicon oxide film, and in the process of relaxing this internal stress, the surface of the resin layer 23 on the reflective layer 19 side is deformed and the surface is The uneven reflection layer 37 having the uneven reflection surface 39 was formed. As described above, the scattering reflection substrate 4
1 was produced.

In this embodiment, the inorganic insulating film has a thickness of 20 nm.
The thickness of this inorganic insulating film was 20 nm.
When it was made larger, the unevenness of the uneven reflection surface was made larger and deeper. Therefore, it is possible to control the reflection characteristics by adjusting the thickness of the inorganic insulating film.

Next, FIG. 2 shows the results of measuring the reflection characteristics of the manufactured scattering reflection substrate 41. In addition, as shown in FIG. 3, the measurement of the reflection characteristic was performed by using the measurement method described in the first embodiment, and the scattering reflection substrate 41 manufactured in the present embodiment was placed on the sample 47 to be measured.

The reflection characteristic of the scattering reflection substrate 41 of this embodiment is shown by the curve b in FIG. The curve b exceeds 100% when the reflection angle is from 10 degrees to 50 degrees, and a sufficiently high reflectance can be obtained within a range of ± 20 degrees centering on the regular reflection angle of 30 degrees. As described above, the scattering reflection substrate manufactured by the manufacturing method of the present invention has good reflection characteristics, has a small parallax, and can realize bright scattering reflection. Further, although the reflectance is lower than that of the scattering / reflecting substrate manufactured in the first embodiment, the range of the scattering angle exceeding 100% is wide, and the scattering / reflecting substrate manufactured in the first embodiment is large. The one with higher scattering property was obtained.

Further, unlike the conventional method, a photolithography step is not required, a step of applying the resin layer 23, a step of forming a metal reflection film (reflection layer 19), and a step of forming an inorganic insulating film by a sputtering method. It was possible to form the scattering reflection substrate by a simple process.

Next, a reflection type liquid crystal display device using the scattering reflection substrate according to the present embodiment described above will be described. FIG. 7 is a cross-sectional view showing the method of manufacturing the reflective liquid crystal display device of this embodiment. Hereinafter, description will be given with reference to FIG. 7.

Instead of the scattering / reflecting substrate used in the first embodiment described above, FIG. 6C manufactured in this embodiment.
A reflective liquid crystal display device is manufactured by using the scattering reflection substrate 41 of FIG. The manufacturing method is the same as in the first embodiment. However, the difference from the first embodiment is that the inorganic insulating film 25 is formed on the reflection layer 19 in the scattering reflection substrate 41. As shown in FIG. 7, the reflective liquid crystal display device of the present embodiment seals the liquid crystal layer 21, the lower substrate 29 and the upper substrate 31 facing each other so as to sandwich the liquid crystal layer 21, and the liquid crystal layer 21. And a polarizing plate 27 provided on the opposite side (outside) of the liquid crystal layer 21 of the upper substrate 31.

Also in the method of manufacturing the reflection type liquid crystal display device of this embodiment, the lower substrate 29 and the upper substrate 31 are manufactured similarly to the first embodiment. Similar to the first embodiment, the lower substrate 29 is formed by a color filter forming step of forming the color filter 33 on the scattering reflection substrate 41,
An overcoat layer forming step of forming the overcoat layer 35 on the color filter 33, and the overcoat layer 3
5 for forming the first electrode 15 on the electrode 5.

Further, the same method as in the first embodiment can be used for the upper substrate 31, and the electrode forming step of forming the second electrode 17 on the other glass substrate 13 and the second electrode 1
The upper substrate 31 is manufactured by an alignment film installation step of forming an alignment film (not shown) on the substrate 7.

Then, as in the first embodiment, the lower substrate 29 and the upper substrate 31 are separated from each other by the first electrode 15 on the first substrate 11 and the second electrode 17 on the second substrate 13. The stripe patterns of the first electrode 15 and the stripe pattern of the second electrode 17 are arranged so as to face each other and be orthogonal to each other. By arranging in this way, a pixel is formed at a portion where the first electrode 15 and the second electrode 17 intersect. Then, as shown in FIG. 7, a sealing material (not shown) is formed between the lower substrate 29 and the upper substrate 31,
The liquid crystal layer 21 is enclosed by this sealing material. The same material as that of the first embodiment is used for the liquid crystal layer 21.

FIG. 5 shows the result of measurement of the reflection characteristics of the reflection type liquid crystal display device formed as described above. For the measurement of the reflection characteristics, the above measuring method shown in FIG. 3 was adopted. The reflection characteristic of the reflective liquid crystal display device of this embodiment is shown by the curve b in FIG.
Indicate. 100 at a reflection angle of 10 to 50 degrees
%, And a sufficiently high reflectance could be obtained within a range of ± 20 degrees around the regular reflection angle of 30 degrees.

As described above, the photolithography process as in the conventional method is not required, and the coating process of the resin layer 23, the film forming process of the metal reflection film (reflection layer 19), and the sputtering method of the inorganic insulating film 25 are performed. Such as the film formation process by
Since the scattering reflection substrate can be formed in a simple process, a bright reflection type liquid crystal display device having good reflection characteristics, a small parallax, and a bright liquid crystal display device could be manufactured.

[Third Embodiment: FIGS. 2, 5, 8 and 9] FIG. 8 is a cross-sectional view showing a scattering reflection substrate 41 in the present embodiment. This will be described below with reference to FIG. As shown in FIG. 8, the scattering reflection substrate 41 of the third embodiment has a resin layer 23, a reflection layer 19, and an inorganic insulating film 25 on the first substrate 11 made of an insulating glass substrate. And a concave-convex reflective surface 39 is provided on the surface of the reflective layer 19. The structure of each layer in FIG. 8 employs the same material and the same film thickness as in the previous embodiment.

Next, a method for manufacturing the scattering reflection substrate in this embodiment shown in FIG. 8 will be described. The method for manufacturing the scattering / reflecting substrate of this embodiment is the same as that of the second embodiment shown in FIG.
The process is the same as that shown in FIG.

First, similarly to the second embodiment of FIG. 6A, a heat or photocurable transparent resin layer 23 is formed on the first substrate 11 which is a glass substrate of an insulating substrate. ,
As shown in FIG. 6B, an aluminum film is formed as a metal reflection film (reflection layer 19) by a sputtering method,
The film was formed with a film thickness of 0 nm. Furthermore, as shown in FIG. 6C, a silicon oxide film was formed as the inorganic insulating film 25 on the reflective layer 19 by sputtering to have a film thickness of 20 nm. As described above, unevenness was formed on the surface of the reflective layer as shown in FIG. 6C, and the uneven reflective layer 37 having the uneven reflective surface 39 was formed.

Next, in this embodiment, after the step of forming irregularities on the surface of the reflective layer, the first substrate 11 provided with the resin layer, the reflective layer and the inorganic insulating film is placed in a clean oven in a clean oven.
A heating process of heat treatment at 20 ° C. for 1 hour is performed. The heating temperature can be from 140 ° C. to 250 ° C., but the optimum heating temperature is appropriately set. By this heating step, internal stress is generated again due to the difference in thermal expansion coefficient between the metal reflection film forming the resin layer 23 and the reflection layer 19 and the inorganic insulating film 25. The surface of the layer 23 on the reflective layer 37 side is further deformed, and the uneven reflective surface 39 is formed on the surface of the reflective layer 37. The depth of the unevenness is deeper after the heating step than before the heating step, and the size of the unevenness becomes large. In this way, the scattering reflection substrate 41 as shown in FIG. 8 is formed.

Next, FIG. 2 shows the results of measuring the reflection characteristics of the formed scattering reflection substrate 41. For the measurement of the reflection characteristic, the previously described measurement method of FIG. 3 was adopted. A curve c in FIG. 2 is the reflection characteristic of the scattering reflection substrate 41 of this embodiment. The curve c is 10 when the reflection angle is 5 degrees to 55 degrees.
It was over 0%, and a sufficiently high reflectance could be obtained within a range of ± 25 degrees around the regular reflection angle of 30 degrees. The scattering reflection substrate manufactured in this embodiment is 100% more than the curves a and b manufactured in the previous embodiment.
It was possible to obtain a scattering / reflecting substrate having a wide range of reflection angles exceeding 10 and having a higher scattering property as a reflection characteristic. As described above, by using the manufacturing method of the present embodiment, it is possible to realize a bright scattering / reflecting substrate that has excellent reflection characteristics, has a small parallax, and is bright.

Further, unlike the conventional method, a photolithography step is not required, a step of applying the resin layer 23, a step of forming the metal reflection film 19, a step of forming an inorganic insulating film by a sputtering method, and a heat treatment. By carrying out the steps, as shown in FIG. 2, a scattering / reflecting substrate having higher scattering characteristics could be formed.

Next, a reflection type liquid crystal display device using the scattering reflection substrate according to the present embodiment described above will be described. FIG. 9 is a cross-sectional view showing the reflective liquid crystal display device in this embodiment. This will be described below with reference to FIG.

A reflective liquid crystal display device is manufactured by using the scattering reflection substrate 41 of FIG. 8 manufactured in this embodiment instead of the scattering reflection substrate used in the second embodiment described above. The manufacturing method of the reflective liquid crystal display device is the same as that of the second embodiment. As shown in FIG. 9, the reflective liquid crystal display device of the present embodiment seals the liquid crystal layer 21, the lower substrate 29 and the upper substrate 31 facing each other so as to sandwich the liquid crystal layer 21, and the liquid crystal layer 21. And a polarizing plate 27 provided on the opposite side (outside) of the liquid crystal layer 21 of the upper substrate 31.

Also in the method of manufacturing the reflective liquid crystal display device of this embodiment, the lower substrate 29 and the upper substrate 31 are formed as in the previous embodiment. Similar to the first embodiment, the formation of the lower substrate 29 includes a color filter forming step of forming the color filter 33 on the scattering reflection substrate 41, and an overcoat layer forming step of forming the overcoat layer 35 on the color filter 33. And an electrode forming step of forming the first electrode 15 on the overcoat layer 35.

The same method as in the previous embodiment can be used for the upper substrate 31, and the second glass substrate 13 is provided with the second method.
Forming step of forming the electrode 17 of the second electrode 17
The upper substrate 31 is manufactured by an alignment film installation step of forming an alignment film (not shown) on the alignment film.

Then, as in the previous embodiment, the lower substrate 2
9 and the upper substrate 31, the first electrode 15 on the first substrate 11 and the second electrode 17 on the second substrate 13 face each other, and as shown in FIG. A sealant (not shown) is formed between the upper substrate 31 and the liquid crystal layer 21 by the sealant. The liquid crystal layer 21 is also made of the same material as in the above embodiment.

FIG. 5 shows the result of measurement of the reflection characteristics of the reflection type liquid crystal display device thus formed. For the measurement of the reflection characteristic, the above-described measurement method illustrated in FIG. 3 was adopted. FIG. 5 shows the reflection characteristics of the reflective liquid crystal display device of this embodiment.
It is shown by the curve c in the inside. When the reflection angle was from 5 degrees to 55 degrees, it exceeded 100%, and a sufficiently high reflectance could be obtained within a range of ± 25 degrees centering on the regular reflection angle of 30 degrees.

As described above, the photolithography step as in the conventional method is not required, and the step of applying the resin layer 23, the step of forming the metal reflection film 19, and the step of forming the inorganic insulating film by the sputtering method are performed. Further, since the scattering / reflection substrate can be formed by a simple process such as a heat treatment process, a bright reflective liquid crystal display device having good reflection characteristics, a small parallax, and a bright process can be realized.

[0073]

As described above, in the scattering reflection substrate used in the reflection type liquid crystal display device of the present invention, the transparent resin layer which is cured by heat or light and the metal reflection film provided on the upper surface are subjected to heat treatment, Internal stress due to the difference in thermal expansion coefficient is generated between the resin layer and the metal reflection film, and in the process of relaxing this internal stress, the surface of the resin layer on the metal reflection film side is deformed, An uneven reflection surface is formed on the surface of the reflection layer formed.

The scattering reflection substrate used in the reflection type liquid crystal display device of the present invention has an inorganic insulating film in the step of forming the reflecting layer and the inorganic insulating film on the transparent resin layer which is cured by heat or light. Internal stress is generated in the surface of the resin layer, and in the process of relaxing the internal stress, the surface of the resin layer on the reflective layer side is deformed to form an uneven reflective surface on the surface of the reflective layer.

Further, the scattering reflection substrate used in the reflection type liquid crystal display device of the present invention has the inorganic insulating film in the step of forming the reflecting layer and the inorganic insulating film on the transparent resin layer which is cured by heat or light. Internal stress is generated in the, and in the process of relaxing this internal stress, the surface of the resin layer on the reflective layer side is deformed, and further heat treatment is performed on the resin layer and the reflective layer to form a gap between the resin layer and the reflective layer. In addition, due to the difference in the coefficient of thermal expansion, internal stress is generated again, and in the process of relaxing this internal stress, the surface of the resin layer on the reflective layer side is further deformed, forming an uneven reflective surface on the surface of the reflective layer. ing.

By such a method, it is possible to manufacture a scattering reflection substrate having good reflection characteristics, and it is possible to realize a bright reflection type liquid crystal display device with a small parallax. Furthermore, different reflection characteristics can be obtained by the respective methods, and it becomes possible to use the reflection type liquid crystal display device properly depending on the application.

Further, the reflection characteristics can be changed depending on the type and thickness of the resin layer, the type and thickness of the reflective layer, the type and thickness of the inorganic insulating layer, the heat treatment method, etc. It is possible to control the reflection characteristic.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a process of manufacturing a scattering reflection substrate of the present invention.

FIG. 2 is a diagram showing the reflection characteristics of the scattering reflection substrate of the present invention.

FIG. 3 is a schematic diagram for explaining a method for evaluating the reflection characteristics of the scattering reflection substrate of the present invention.

FIG. 4 is a cross-sectional view showing a reflective liquid crystal display device manufactured by the manufacturing method of the present invention.

FIG. 5 is a diagram showing reflection characteristics of a reflective liquid crystal display device manufactured by the manufacturing method of the present invention.

FIG. 6 is a cross-sectional view showing a method for manufacturing the scattering reflection substrate of the present invention.

FIG. 7 is a cross-sectional view showing a reflective liquid crystal display device manufactured by the manufacturing method of the present invention.

FIG. 8 is a cross-sectional view showing a scattering reflection substrate manufactured by the manufacturing method of the present invention.

FIG. 9 is a cross-sectional view showing a reflective liquid crystal display device manufactured by the manufacturing method of the present invention.

[Explanation of symbols]

11 First substrate 13 Second substrate 15 First electrode 17 Second electrode 19 Reflective layer 21 Liquid crystal layer 23 Resin layer 25 Inorganic insulation film 29 Lower substrate 31 upper substrate 33 Color filter layer 37 Concavo-convex reflective layer 39 uneven reflective surface 41 Scatter reflection board

Continued front page    F-term (reference) 2H042 BA03 BA12 BA15 BA20 DA02                       DA12 DA14 DA18                 2H090 HA04 HA07 HB03X HC08                       HD01 JB01 JC03 LA01 LA20                 2H091 FA02Y FA16Y FA41X FB02                       FB08 FC02 LA16 LA18

Claims (17)

[Claims] 1. A step of forming a resin layer on an insulating substrate, a step of providing a reflecting layer on the resin layer, and a step of heating the insulating substrate having the resin layer and the reflecting layer to perform the reflection. And a step of forming irregularities on the surface of the layer. 2. A step of forming a resin layer on an insulating substrate, a step of providing a reflective layer on the resin layer, an inorganic insulating film formed on the reflective layer by a sputtering method, and at the same time the reflective layer is formed. And a step of forming irregularities on the surface of the layer. 3. The method according to claim 2, further comprising a step of heating an insulating substrate having a resin layer, a reflective layer and an inorganic insulating film, after the step of forming irregularities on the surface of the reflective layer. A method for manufacturing the scattering reflection substrate according to. 4. The method of manufacturing a scattering / reflecting substrate according to claim 1, wherein the resin layer is transparent at least in a visible light region. 5. The method of manufacturing a scattering / reflecting substrate according to claim 1, wherein the resin layer has a film thickness of 1 μm to 5 μm. 6. The method of manufacturing a scattering reflection substrate according to claim 1, wherein the reflection layer is made of a metal reflection film. 7. The method according to claim 6, wherein the metal reflection film is made of aluminum or aluminum alloy. 8. The method of manufacturing a scattering reflection substrate according to claim 2, wherein the inorganic insulating film is made of a silicon oxide film. 9. A step of forming a resin layer on at least one of the pair of insulating substrates, a step of providing a reflecting layer on the resin layer, and a step of providing the resin layer and the reflecting layer. Liquid crystal is sealed between the step of heating the insulating substrate to form irregularities on the surface of the reflective layer, the insulating substrate having irregularities on the surface of the reflective layer, and the other insulating substrate. A method of manufacturing a reflection type liquid crystal display device, the method including: 10. A step of forming a resin layer on at least one of the pair of insulating substrates, a step of providing a reflecting layer on the resin layer, and an inorganic insulating layer on the reflecting layer. Forming a film by a sputtering method and simultaneously forming irregularities on the surface of the reflecting layer, and enclosing a liquid crystal between the insulating substrate having the irregularities formed on the surface of the reflecting layer and the other insulating substrate. A method for manufacturing a reflection type liquid crystal display device having the following. 11. The method according to claim 10, further comprising the step of heating an insulating substrate provided with a resin layer, a reflective layer and an inorganic insulating film after the step of forming irregularities on the surface of the reflective layer. A method for manufacturing the reflective liquid crystal display device described. 12. The method of manufacturing a reflective liquid crystal display device according to claim 9, wherein the resin layer is transparent at least in a visible light region. 13. The method of manufacturing a reflective liquid crystal display device according to claim 9, wherein the resin layer has a film thickness of 1 μm to 5 μm. 14. The method of manufacturing a reflective liquid crystal display device according to claim 9, wherein the reflective layer comprises a metal reflective film. 15. The metal reflective film is made of aluminum or an aluminum alloy.
5. The method for manufacturing the reflective liquid crystal display device according to item 4. 16. The method of manufacturing a reflective liquid crystal display device according to claim 10, wherein the inorganic insulating film is a silicon oxide film. 17. A color filter forming step of forming a color filter layer after the step of forming irregularities on the surface of the reflective layer, an overcoat layer forming step of forming an overcoat layer on the color filter layer, An electrode forming step of forming an electrode on the overcoat layer, an alignment film setting step of setting an alignment film subjected to an alignment treatment on the electrode, an electrode forming step of forming an electrode on the other insulating substrate, and the other An alignment film setting step of setting an alignment film that has been subjected to an alignment treatment on an electrode of an insulating substrate, and a bonding step of bonding one insulating substrate and the other insulating substrate with a sealing material. 9. The method for manufacturing a reflective liquid crystal display device according to claim 9 or 10.