JPH08327997A - Method for manufacturing color liquid crystal display device - Google Patents

Abstract

(57) [Abstract] [Purpose] A colored pattern of three primary colors constituting a color liquid crystal display device is formed by a thermal transfer method. [Constitution] Sublimation dye 3 is formed on a glass substrate SUB2 on which a black matrix BM and a dyeing layer 1 are formed in advance by a thermal transfer method.
Is transferred, the width of the voltage pulse applied to the heating element 4 for heating the thermal transfer film carrying the sublimable dye 3 is adjusted to adjust the amount of heat required for sublimation and diffusion of the sublimable dye.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device, and more particularly to a method of manufacturing a color liquid crystal display device having a color filter formed of a coloring layer formed by applying the principle of a thermal transfer system.

[0002]

2. Description of the Related Art A liquid crystal display device is classified into a simple matrix type and an active matrix type, depending on the pixel selection method.

In a simple matrix type liquid crystal display device, a liquid crystal such as STN is sealed between two sets of intersecting electrodes, and pixels are formed at the intersections of the electrodes.

On the other hand, the active matrix type liquid crystal display device has a non-linear element (switching element) corresponding to each of a plurality of pixel electrodes arranged in a matrix.
Since the liquid crystal in each pixel is theoretically always driven (duty ratio 1/1), the active method has a higher contrast than the simple matrix method which adopts the time division driving method. It is becoming an indispensable technology especially for color liquid crystal display devices. A thin film transistor (TFT) is known as a typical switching element.

The basic structure of a liquid crystal display device is such that a liquid crystal composition is filled between one transparent substrate and the other substrate on which individual electrodes or switching elements are formed. A color liquid crystal display device is configured by including a color filter. A vertical electric field method in which a common electrode is formed on the one substrate side and a lateral electric field method in which a common electrode is also formed on the other substrate side are known.

FIG. 6 is an exploded perspective view showing each component of a liquid crystal module adopting a TFT type liquid crystal display device as an example of a color liquid crystal display device to which the present invention is applied.
SHD is a frame-shaped shield case (metal frame) made of a metal plate, LCW is a liquid crystal display window as its display area,
PNL is a liquid crystal display panel, SPB is a light diffusion plate, MFR is an intermediate frame, PCB3 is an inverter circuit, BL is a backlight, BLS is a backlight support, and LCA is a lower case. Due to the relation, the respective members are stacked to assemble the liquid crystal module MDL.

The module MDL is a shield case SH.
The whole is fixed by the claw CL and the hook FK provided on D.

The intermediate frame MFR is formed in a frame shape so as to form an opening corresponding to the display window LCW, and the frame portion has a diffusion plate SPB, a backlight support BLS, and various circuit components in accordance with the shapes and thicknesses thereof. There are irregularities and openings for heat dissipation.

The lower case LCA also serves as a reflector for backlight light, and a reflection mountain RM is formed corresponding to the fluorescent tube BL so as to reflect light efficiently.

The backlight is not limited to the back lighting system shown in the figure, but there is also a back lighting system which employs a side lighting system in which a light source is arranged on the side surface of the liquid crystal display panel PNL. In this case, a surface light source structure mainly including a light guide is provided below the diffusion plate SPB.

FIG. 7 is a cross-sectional view of an essential part of a liquid crystal element for explaining a structural example of the TFT type liquid crystal display device shown in FIG. 6, and shows a lower glass substrate SUB1 and an upper glass substrate SUB2 with a liquid crystal composition layer LC sandwiched therebetween. Consists of.

On the lower glass substrate SUB1 side, a gate electrode GT, gate insulating films AOF and GI, a semiconductor layer AS,
The thin film transistor TFT1 including the source / drain electrodes SD1 and SD2 and the transparent pixel electrode ITO1 are provided, and the protective film PSV1 and the lower alignment film ORI1 are further stacked.

The upper glass substrate SUB2 also has a black matrix BM as a light-shielding film and a color filter FIL.
(R), FIL (G), FIL (B), protective film PSV
2. The common transparent pixel electrode ITO2 (COM) and the upper alignment film ORI2 are laminated.

A silicon oxide film SIO formed by a dipping process or the like is provided on the opposing surfaces of the lower glass substrate SUB1 and the upper glass substrate SUB2, and the above layers are laminated on the silicon oxide film SIO. Has been done.

Between the lower glass substrate SUB1 and the upper glass substrate SUB2, a liquid crystal composition layer (hereinafter also simply referred to as a liquid crystal layer or liquid crystal) LC is sealed along the edge thereof except for a liquid crystal filling port. A seal pattern SL made of epoxy resin or the like is provided on the. The material of the seal pattern SL is, for example, epoxy resin.

The common transparent pixel electrode ITO2 (COM) on the upper glass substrate SUB2 side is connected to the lead wiring INT formed on the lower glass substrate SUB1 with silver paste material AGP at least at one place (four corners in the figure). There is. The lead wiring INT is formed in the same manufacturing process as a gate terminal and a drain terminal (not shown).

The alignment films ORI1, ORI2, the transparent pixel electrode ITO1, and the common transparent pixel electrode ITO2 are formed inside the seal pattern SL.

The polarizing plates POL1 and POL2 are formed on the outer surfaces of the lower glass substrate SUB1 and the upper glass substrate SUB2, respectively.

Further, the liquid crystal composition layer LC is sealed in a region partitioned by a seal pattern SL between a lower alignment film ORI1 and an upper alignment film ORI2 which set the orientation of liquid crystal molecules. The lower alignment film ORI1 is formed on the protective film PSV1 on the lower glass substrate SUB1 side.

This liquid crystal display device has a lower glass substrate SU.
The layers described above are stacked on the B1 side and the upper glass substrate SUB2 side, respectively, and the seal pattern SL is formed on the upper glass substrate SUB2 side, on which the lower transparent glass substrate SU is formed.
Liquid crystal is injected from the opening of the seal pattern SL by overlapping B1 and the injection port is sealed with an epoxy resin or the like to form a liquid crystal composition layer, and then the lower glass substrate SUB is formed at a predetermined position.
It is obtained by cutting 1 and the upper glass substrate SUB2.

Therefore, the i-type semiconductor layer AS of the thin film transistor TFT1 is sandwiched by the black matrix BM and the gate electrode GT, which are the upper and lower light-shielding films, and the external natural light and the backlight are not exposed. The black matrix BM is formed in a grid shape around each color pixel, and each grid partitions the effective area of one color pixel. As a result, the contour of each color pixel becomes clear and the contrast is improved. That is, the black matrix BM has the functions of blocking the i-type semiconductor layer AS and improving the contrast.

As shown in FIG. 6, the black matrix BM is also formed in a frame shape in the peripheral portion and extends to the outside of the seal pattern SL, so that the reflected light caused by the structure of a mounting machine such as a personal computer is generated. Leakage light is prevented from entering the matrix portion.

On the other hand, the black matrix BM is retained inside the edge of the substrate SUB2 by about 0.3 to 1.0 mm, and is formed so as to avoid the cut region of the substrate SUB2.

In the area defined by the black matrix BM, a plurality of color filters FIL forming a pixel pattern are formed.
(Generally, red (R): FIL (R), green (G): FI
L (G), blue (B): FIL (B) is adopted, but yellow, magenta, and cyan, which are complementary colors to these colors, are also adopted) are arranged according to a predetermined rule. .

For example, the color filter FIL (G) is formed on the side of the upper glass substrate SUB2, and the black matrix BM is partially overlapped and surrounded by the surrounding area to define a predetermined area.

Conventionally, the black matrix is obtained by a method of obtaining a grid pattern by a photoetching method after depositing metal chromium or the like, or by adding a coloring agent for blackening to a photosensitive resin and applying it, followed by photolithography. A method of forming a grid pattern using a process is known.

As a method of forming a color filter substrate for a liquid crystal display device, a dyeing method mainly using a photolithography process, a pigment dispersion method, or an electrodeposition method,
Printing methods and the like are known.

In a pigment dispersion method using a photolithography process as a typical method for forming the black mask and the color filter, a black matrix is first formed and then a predetermined pigment (for example, a red pigment) is dispersed in the photosensitive material. Forming a red filter by applying a conductive material onto the black matrix, exposing through a mask having an opening only in the red filter region and developing, and subsequently forming green and blue filters in the same manner. To do.

An active matrix type liquid crystal display device using thin film transistors is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-309921, "1.
2.5-inch active matrix color liquid crystal display ", Nikkei Electronics, pages 193-210,
Known for publication on December 15, 1986 by Nikkei McGraw-Hill, Inc. In this example, the active matrix method has been described, but the low-priced super twisted nematic (STN) liquid crystal and twisted nematic (T
N) Since a thin film transistor does not exist in a color liquid crystal display device using a liquid crystal, this light shielding black matrix pattern BM is not necessarily required. The present invention relates to a general color liquid crystal display device, and in this case as well, it is applicable except for the black matrix process.

Conventionally, as a method of forming a color filter for a liquid crystal device, a dyeing method mainly using a photolithography process, a pigment dispersion method, an electrodeposition method, or a printing method is known.

FIG. 8 is a process chart for explaining a method of manufacturing a color filter substrate using a pigment dispersion method using the most general photolithography process.

In the figure, in the black matrix BM forming step, metal chromium (Cr) or the like is used to form a pattern by a photo-etching method, and a photosensitive resin is provided with a coloring agent for blackening. For example, there is one formed by using a photolithography process (hereinafter also simply referred to as a photolithography process) after adding and coating.

To form the black matrix BM using a Cr film, a Cr film is formed on a -1 transparent substrate and then -2C.
A photoresist is applied on the r film, exposed through an exposure mask having openings of → -3 black matrix pattern, developed by → -4, and etched by -5,
→ −6 It is formed through a process of peeling the photoresist.

Further, the formation of the black matrix by the pigment dispersion system is carried out by applying a black resist to a transparent substrate -1, exposing it through an exposure mask having openings of a black matrix pattern, and developing it by -3. , →
-4 is formed through a curing step.

In the above or in the black matrix BM
In the step of forming a colored pixel on the substrate on which the colored pixel is formed, a photosensitive material having -1 pigment particles added therein is applied, and then a red (R) colored coloring material is applied,
-2 through the exposure mask corresponding to the red colored portion,
→ -3 development, →→ -4 post-baking is performed to color red pixels.

Similarly, a -5 green (G) color coloring material is applied, and as in the above, -6 exposure, -7 development, -8
Post-baking is performed to color green pixels, -9 blue (R) color coloring material is applied, and -10 exposure, -11 development and -12 post-baking are performed to color green pixels in the same manner as above. As a result, the required three-color coloring pattern is formed.

FIG. 9 is a sectional view of an essential part for explaining the structure of a general color filter formed by the manufacturing method described with reference to FIG.

In the figure, ITO2 is a transparent electrode formed on the surface of the color filter, PSV2 is a transparent protective film formed on the colored layer (colored color pixels), and FIL.
(R), FIL (G), and FIL (B) are colored pixels of each color, SUB2 is a glass substrate, and BM is a black matrix.

The silicon oxide film SIO may not be formed depending on the application of the liquid crystal display device and the material of the transparent substrate SUB2.

As shown in the figure, the structure of the color filter is usually a colored layer FIL in which pattern regions are separated in a mosaic or vertical stripe pattern for each pixel or each color.
(R), FIL (G), FIL (B) on the protective film layer P
The SV2 is formed, and the transparent electrode ITO2 is further formed on the SV2.

By forming the color filter structure in this way, it is possible to secure heat resistance to a temperature of about 200 ° C. by vapor deposition or sputtering when forming the transparent electrode ITO2 and heat treatment to the heat treatment in the subsequent module process to a practically acceptable level. A color filter having good color reproducibility is formed.

On the other hand, a method of collectively coloring the three primary colors for the purpose of reducing the manufacturing cost and improving the production capacity has been studied for practical use, and the thermal transfer method is one of them.

The thermal transfer method applied to color printing used in color copying and video printers will be described below.

FIG. 10 is an explanatory view of a thermal transfer system used for color printing, in which (a) shows a schematic manufacturing process and (b) shows.
[Fig. 3] is a typical schematic view of a manufacturing apparatus.

In the figure, the resist coating step (a) is a step of forming an image receiving paper, and in this example, as shown in (b), the image receiving paper has a base paper coated with a dyeing resin layer, and An abnormal transfer prevention layer is laminated thereon.

The abnormal transfer preventive layer prevents the ink from being thermally diffused to an excessive area during thermal transfer.

Next, the image receiving paper is colored by a thermal transfer process. The thermal transfer film 2 is obtained by applying a stick resistant layer on one side of a base film such as polyethylene terephthalate,
The other is coated with a coloring agent.

The color of the colorant is achieved by a color mixing method using the three primary colors of yellow (Y), cyan (C) and magenta (M).

At present, two types of thermal transfer methods are generally used depending on the type of coloring material. In the first method, a coloring agent such as a pigment is mixed with wax to form a coloring material, and the wax is transferred together with the wax to the object to be colored by heating. The advantage of using this colorant is that plain paper can be used for the object to be colored.

In the second method, as shown in FIG. 9 (b), a thermal transfer film 2 in which a mixture of a sublimable dye and a binder resin is applied as an ink layer 3 on a base film is used. The portion transferred when heated is a dye, and the phenomenon of dye sublimation due to heating is used. A transparent polymer dyeing resin film layer is required as the dyeing layer.

However, in the present invention in which this thermal transfer method is applied to the manufacture of a color filter substrate of a liquid crystal display device, a dye-proof area is formed to prevent the dye from thermally diffusing to an extra area from the structure of the color filter. The abnormal transfer prevention layer described above is not used.

In the present invention, a transparent substrate such as a glass substrate is used instead of the base paper, and the method using wax has a problem in heat resistance. Therefore, the second method is adopted as a better method. are doing. Although the thermal head is used as the heating element 4, a laser may be used.

An example of applying the second method of the thermal transfer method to a color filter of a color liquid crystal display device is described by D. Harrison and MC Olydfield, “The Youth of Color Filter Arrays, Proceedings of the Nineth International Congress on Advances. Innon
Impact Printing Technologies, 382
Pp. 384, 1993 (DJ Harrison and MCOlidfie
ld, "The Use of Thermal Dye Transfer Technology fo
r the Fabrication of Color Filter Arrays ", Proceed
ings of the 9th International Congress on Advances
in Non-Impact Printing Technologies, page 382-38
4 (1993)) and US Pat. No. 5,166,126.

[0054]

As shown in FIG. 7, the colored layer of the color filter which becomes the pixel pattern in the above-mentioned prior art is formed by a method mainly based on the photolithography process. In that case, the manufacturing process becomes long, which is the biggest cause of cost increase.

Further, the photolithography process always involves an exposure process using light, and is a method that requires a highly accurate mask as the pattern becomes finer. Further, a wet development process using a liquid chemical is an essential condition for patterning the exposed polymer layer.

Next, as coloring layers, red (R), green (G),
In order to form the three colors of blue (B), the above-mentioned exposure,
There is a problem that the developing process is required at least three times.

When the liquid crystal display device is actually used, a plurality of colored layers are formed separately, so that the film thickness of each color becomes uneven, and the transparent electrode for driving the liquid crystal on the protective film is well formed. If it cannot be formed, or if it is assembled with the counter electrode substrate holding a certain gap through the protective film, the transparent electrode, and the alignment film, there is a problem that the variation in the film thickness of the liquid crystal layer between each pixel becomes large. It was

In particular, for the STN type liquid crystal display device, in order to improve the response speed and the viewing angle characteristics, it is necessary to make the thickness variation of the liquid crystal layer smaller than that of the TN type liquid crystal display device. Therefore, if the liquid crystal layer in the display surface has a variation in film thickness, color unevenness occurs in that portion, which is extremely disadvantageous for stabilizing the optical characteristics.

On the other hand, as shown in FIG. 9, it is possible to simplify the coloring process by adopting a conventional thermal transfer system using a sublimable dye as a manufacturing process.

However, in the case where the coloring base layer (adhesion layer) formed on the glass substrate is colored by the thermal transfer method, compared with the case where the sublimation dedicated paper (image receiving paper in FIG. 9) is colored, Due to low thermal conductivity and large heat capacity, a large amount of heat energy is required to increase the coloring density. For example, when a thermal head is used as a heating element and thermal transfer is performed on the dyeing base layer on the glass substrate, the applied voltage needs to be 1.5 times or more as compared with the sublimation dedicated paper. Therefore, the power consumption at the time of thermal transfer is large, and the temperature of the heating element is high, so that the donor sheet (thermal transfer film) is easily burnt out, the life of the heating element is shortened, and the heating element and the donor sheet (thermal transfer film). Problems such as deterioration of slipperiness between and occur.

An object of the present invention is to adopt a thermal transfer system as a manufacturing process, increase a coloring density while reducing a heat generation temperature load of a heating element, have high productivity and have a color filter having an excellent optical characteristic. It is to provide a method for manufacturing a liquid crystal display device.

[0062]

That is, in order to achieve the above object, the first invention according to claim 1 is a transparent substrate provided with a color filter comprising a colored layer pattern of three primary colors formed by a thermal transfer method. In a method for manufacturing a color liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates including, a thermal transfer film carrying a sublimation dye on a dyeing layer applied on the transparent substrate is placed, The heating in the dyeing step includes at least a dyeing step of transferring the sublimation dye to the dyeing layer by heating the thermal transfer film by a heating element that heats by applying a pulse to color the dyeing layer. It is characterized in that the color density of the dye-receiving layer is adjusted by changing the length of the application time of the electric pulse applied to the body.

In the second aspect of the present invention, the application time of the electric pulse to the heating element is the minimum heat capacity that can secure the amount of the dye required for forming the colored layer. The dyeing layer is colored for a period of time or more.

Further, a third invention according to claim 3 is
The heating element colors the dyeing layer at a temperature equal to or higher than the diffusion start temperature of the dye per one thermal transfer.

Further, the fourth invention according to claim 4 is
The thickness of the colored layer is 1 μm or more.

The fifth invention according to claim 5 is
It is characterized in that the layer to be colored is composed of a set of yellow, magenta and cyan, or a set of red, green and blue.

[0067]

In the structure of the first invention, the dyeing layer applied on the transparent substrate is colored by placing a thermal transfer film carrying a sublimation dye on the dyeing layer and applying an electric pulse. The sublimation dye is transferred to the dye-receiving layer by heating the thermal transfer film with a heating element that generates heat.

At this time, the color density of the dyed layer is adjusted by changing the length of the application time of the electric pulse applied to the heating element.

In the structure of the second aspect of the invention, the application time of the electric pulse to the heating element is equal to or longer than the time for obtaining the minimum heat capacity that can secure the amount of the dye required for forming the colored layer. By doing so, the dyeing layer is colored.

Further, in the configuration of the third invention,
The dyeing layer is colored by setting the temperature of the heating element to a temperature not lower than the diffusion start temperature of the dye for one thermal transfer of the dyeing layer.

Further, in the configuration of the above-mentioned fourth invention,
By setting the thickness of the colored layer to 1 μm or more, the optical density after coloring is secured.

Then, in the configuration of the fifth invention,
A so-called full-color display is possible by configuring the colored layer with a set of yellow, magenta, and cyan colors, or a set of red, green, and blue.

As described above, in the present invention, the coloring density (optical density) of the dyeing layer is changed by changing the length of the electric pulse application time to the heating element used for thermal transfer, that is, the pulse width.
Is adjusted.

The formation of the black matrix and the transparent pixel electrodes other than the color filter constituted by the colored layer adopts a normal photolithography technique.

On the other hand, as the material of the black matrix, the dye-adhering layer, the protective film and the transparent pixel electrode, a commercially available material or the material disclosed in the official gazette described in the section of Examples described later is used.

Further, in order to form the black matrix, the protective film and the transparent pixel electrode, ordinary vapor deposition, sputtering or coating method is used.

By coloring the dyeing layer by the above-mentioned thermal transfer method according to the present invention, the dye diffusion property of the dyeing layer formed on the glass substrate is improved and the coloring density is increased. Therefore, even if the maximum heat generation temperature of the heating element is lowered, it is possible to obtain a colored layer having a coloring density that satisfies the specifications of the color filter for the color liquid crystal display device.

Further, burnout of the thermal transfer film and deterioration of the sliding property between the heating element and the thermal transfer film are prevented.

[0079]

Embodiments of the present invention will now be described in detail with reference to the drawings.

In all the drawings, components having the same function are designated by the same reference numerals, and repeated description thereof will be omitted as much as possible.

FIG. 1 shows a voltage characteristic of a heating applied pulse to a heating element and a temperature characteristic of the heating element in a coloring step of a dyeing layer for explaining an embodiment of a method for manufacturing a color liquid crystal display device according to the present invention. 3A and 3B are explanatory views of the positional relationship between the heating element and the color filter side substrate, wherein (a) is a voltage pulse applied to the heating element, (b) is a heating temperature characteristic of the heating element, and (c) is a heating element and a color filter. It is a schematic diagram which shows the positional relationship of a board | substrate.

In the figure, 1 is a dyeing layer, 2 is a thermal transfer film, 3 is a sublimable dye, 4 is a heating element (thermal head), and FIL (1) is a first colored layer (first color filter). , FIL (2) is the second position of the first colored layer (first color filter), FIL (N) is the Nth position of the first colored layer (first color filter), BM is a black matrix, SUB2 is a glass substrate, and SIO is a silicon oxide film. The black matrix BM and the dyed layer 1 are previously formed on the glass substrate SUB2.

As shown in (c), the thermal transfer film 2 coated with the sublimable dye of the first color is placed on the dyed layer 1, and the first colored layer of the dyed layer 1 is first placed. First position FIL
The heating element 4 is located at the dyed position in (1). At this position, a pulse having the width T _ON 1 shown in (a) is applied to the heating element 4. As a result, the sublimable dye 3 applied to the thermal transfer film 2 colors the first position FIL (1) of the dyeing layer 1.

Next, the heating element 4 moves to the dyeing position of the second colored layer FIL (2) of the first colored layer of the dyeing layer 1 and is covered by the second colored layer FIL (2) of the first colored layer. At the same time when the heating element 4 is located at the dyeing position, a pulse of width T _ON 2 is applied to the heating element 4.

Hereinafter, the width T is synchronized with the movement of the heating element 4 to the dyed position of the Nth position FIL (N) of the first colored layer.
_{Apply ON} N pulse.

Pixels of the same color are required to have a uniform color density within the plane of the color filter. Therefore, when the heating element 4 is sufficiently cooled during the off time when no voltage pulse is applied, Pulse application time, that is, pulse width T _ON 1 to T
_ON N is the same on the surface to be colored.

The transfer color density of the colored layer colored in this way is the energy applied with the applied voltage, the applied current and the applied time applied to the heating element 4, the thermal transfer film 2 of the heating element 4 and the deposition. It changes depending on the pressure applied to the dye layer 1 or the like.

In general, when the sublimation paper is colored in the thermal transfer process, the applied voltage time required for one thermal transfer is 0.
5 to 5 milliseconds. However, in order to color the dyeing layer 1 on the glass substrate by the thermal transfer process, since the glass substrate has a small thermal conductivity and a large heat capacity, the sublimable dye is sublimated and diffused. The required applied energy is larger than in the case of sublimation paper.

When the applied energy is large, the maximum heat generation temperature increases when the application time is shortened and the applied voltage value is increased, the thermal transfer film 2 burns out, and the sliding property between the thermal transfer film 2 and the heating element 4 is increased. Of the sublimation dye, heat fusion of the sublimable dye to the dyeing layer 1, and the like.

Therefore, in order to lower the maximum heat generation temperature, the applied voltage value is reduced and the application times T _ON 1 to T _ON N are adjusted to supply the amount of heat necessary for the sublimation dye to sublime and diffuse. .

FIG. 2 shows the voltage characteristics of the heating applied pulse to the heating element and the temperature of the heating element in the coloring step of the dyeing layer for further explaining one embodiment of the method for manufacturing a color liquid crystal display device according to the present invention. 4A and 4B are explanatory diagrams of the characteristics and the positional relationship between the heating element and the substrate on the color filter side, where FIG. 7A is a voltage pulse applied to the heating element, FIG.
(C) is a schematic diagram showing a positional relationship between a heating element and a color filter substrate.

In the figure, the applied voltage value to the heating element 4 is reduced so that the application time T _ON 1 to T _ON N ≧ 10 milliseconds.

FIG. 3 shows the voltage characteristics of the heating applied pulse to the heating element and the temperature of the heating element in the coloring step of the dyeing layer for further explaining one embodiment of the method for manufacturing a color liquid crystal display device according to the present invention. 4A and 4B are explanatory diagrams of the characteristics and the positional relationship between the heating element and the substrate on the color filter side, wherein (a) is a voltage pulse applied to the heating element, (b) is a heating temperature characteristic of the heating element,
(C) is a schematic diagram showing a positional relationship between a heating element and a color filter substrate.

In the figure, the time T1, T2, ... TN in which the temperature of the heating element 4 is 100 ° C. or more per transfer
Setting to ≧ 10 milliseconds, the dyeing layer 1 is colored by a thermal transfer process.

The times T1, T2, ... TN in which the temperature of the heating element 4 is 100 ° C. or higher can be realized by adjusting any one or a combination of applied voltage and current, and applied time.

FIG. 4 is a process chart for explaining an example of a method of manufacturing a color film substrate constituting a color liquid crystal device according to the present invention.

First, (a) the black matrix BM is formed on the glass substrate SUB2 or on the coating layer SIO on the glass substrate SUB2.

Next, (b) a photosensitive resin, which is a transparent dye-receiving layer 1, is coated and formed on the black matrix BM,
A colored layer pattern corresponding to each pixel or each color, that is, a color filter layer FIL by the photolithography process.
The portions to be (R), FIL (G), and FIL (B) are formed in advance.

In this example, a photosensitive resin is used as the dye-receiving layer 1. That is, a resin composition in which an acryloyl group is added with a negative-type photosensitive aromatic-containing material is mainly used, and is applied by spin coating or the like in a film thickness range of about 1 to 1.5 μm.

Instead of repeatedly performing the photolithography process for each primary color on the dyeing layer 1 as in the conventional case, a pattern of all colors is formed at once by one photolithography process.

This pattern is formed in a mosaic shape or a vertical stripe shape corresponding to the color arrangement of the color filter. The cross-sectional shape of the pattern of the three primary colors is formed such that the patterns for each pixel or each color are divided into regions with gaps separated by grooves. Thereafter, (c) the thermal transfer film 2 coated with the sublimable dye 3 is placed on the layer 1 to be colored, and a predetermined area is heated by the heating element 4 (thermal head) for coloring.

This is because, in this example, the dye-receiving layer 1 can be made thin and the gaps between the color patterns are separated, so that deeper coloring is possible.

Further, (d) in order to improve the heat resistance of the color filter, the protective film PSV2 is formed by color filter layers FIL (R), FIL (G), which are colored layer patterns,
Form on FIL (B) and in their gaps.

According to the structure of the color filter substrate manufactured in this example, the dye-adhering layers of the respective colors are separated, and the dye-proof region between them is formed by the protective film PSV2. Therefore, the liquid crystal display device after dyeing is performed. It is possible to effectively prevent the color mixture caused by the horizontal diffusion of the sublimable dye caused by various kinds of heating in the assembling process and the fading of the coloring pattern itself.

Incidentally, (e) the transparent electrode ITO2 is formed on the protective film PSV2 by sputtering.

According to this example, heat resistance is improved to prevent color mixture of dyes, the gap variation between ITO1 and ITO2, which is a liquid crystal driven transparent electrode in each pixel, is minimized, and optical characteristics are improved. An excellent and highly reliable color liquid crystal display device can be provided.

FIG. 5 is a process chart for explaining another example of the method for manufacturing a color film substrate constituting the color liquid crystal device according to the present invention. FIL in the figure represents a colored layer, which is different from FIG. FIL (R), FIL (G), FIL
The layer (B) is formed by coloring the continuous transparent dye-receiving layer 1 with a sublimation dye, and the colored layers are not colored FIL.
The area is divided at (T), and the structure is such that the colors do not overlap.

First, (a) the black matrix BM is formed on the glass substrate SUB2 or on the coating layer SIO on the glass substrate SUB2.

In consideration of the light shielding effect, 800 to 12 in this example.
A metal chromium film having a film thickness of about 00Å was used. The black matrix BM is not limited to metallic chrome,
It is also possible to use a multilayer film of metallic aluminum, nickel or chromium oxide and chromium.

In some cases, the film is formed by using a photosensitive organic film to which a coloring agent for making black is added, and in that case, the film thickness is determined from the required transmittance value. As a material when using an organic film, CK-5 manufactured by Fuji Hunt Co., Ltd.
001 (trade name) and DCFK series (trade name) manufactured by Nippon Kayaku Co., Ltd., all of which are mixed systems of carbon and black pigment or carbon and three primary color pigments.

The method of forming the black matrix BM pattern uses a photolithography process in order to improve the overall dimensional accuracy and to serve as a reference for forming other colored pixels.

As described above, the black matrix B is previously prepared.
On the glass substrate SUB2 on which M is formed, the transparent dye-receiving layer 1 is applied by spin coating or the like to have a film thickness of 1 μm or more, and then heated and dried.

Various materials can be considered as the material for the dyeing layer 1, but in this example, a resin composition containing an acryloyl group, which is a negative-type photosensitive aromatic-containing material, is mainly used. .

A novolac resin can also be used as the aromatic-containing material. These photosensitive resin compositions are disclosed in JP-A-4-175755 and JP-A-4-17.
An example is also shown in Japanese Patent No. 5754. Others, US Pat. No. 4,923,860, US Pat. No. 4,96
No. 2,081 and US Pat. No. 5,073,534
The materials described in the specification and the like may be used, and polycarbonate, vinyl chloride, polyurethane, polyester, polyamide, polyacrylonitrile, polycaprolactone and the like can also be used.

In this example, since the patterning of the colored layer is not necessary, a non-photosensitive material can be used, and polyester resin Byron # 200 (trade name) manufactured by Toyobo, cellulose acetate resin, polystyrene, polypropylene, polyethylene terephthalate, Acrylic resin or the like can be used.

Next, (b) the black matrix B
A thermal transfer film 2 made of a base film of polyethylene terephthalate having a thickness of, for example, about 4 μm, which is coated with a sublimable dye 3 in advance so as to cover the transparent dye-receiving layer 1 formed on M.
A desired area is partially heated by the heating element 4 (thermal head) through the, and the sublimation layer 1 is colored by utilizing the sublimation property of the dye.

The sublimable dye 3 must be selected according to the type of the dyeing layer 1 to be thermally transferred. In this example, commercially available disperse dyes and cationic dyes manufactured by Nippon Kayaku Co., Ltd. were used.

For example, as the three primary colors, red is Kayaset Red B or Kayaset Scarlet 926, and green is Kayaset Yellow AG and Kayaset Blue 7.
14 mixtures, one set using Kayaset Blue 714 for blue, or Kayaset Yellow A- for yellow.
One set using Kayaset Blue 714 for G and cyan and Kayaset Red B for magenta is adopted (all the above names are trade names).

As the method of partial heating described above, a thermal head is used as the heating element 4, but a laser may be used.
Generally, a laser is suitable for forming a pattern with high definition.

In this example, the colored layers, that is, the color filters FIL (R), FIL (G), and FIL (B) are divided by providing a transparent non-colored area FIL (T) of the adhered layer in the dye-proof area. Therefore, even if the dyes are diffused in the horizontal direction by sputtering during the formation of the transparent electrode ITO2 and various annealing processes thereafter, color mixture is prevented and the dye is covered in the black matrix region.

In this example, the end portions of the color filters FIL (R), FIL (G), and FIL (B), which are colored layers, are formed so as to overlap the black matrix, but the sublimation dye 3 and Depending on the combination of the layers 1 to be colored, the diffusivity may be large, and the transparent uncolored region F
It is also necessary to expand IL (T).

Further, (c) the color filters FIL (R), FIL (G,) FIL which are colored layers are formed by forming the protective film PSV2 in order to improve the heat resistance of the color filter.
It is formed on (B). Although it depends on the material to be colored, since the sublimable dye is used, the color filters FIL (R), FIL (G), which are colored layers, are near the sublimation temperature of the dye.
Decolorization occurs from the boundary of FIL (B), which is observed as deterioration of the color filter.

Therefore, the protective film layer PSV2 is formed on the colored layer in order to prevent vertical diffusion and sublimation of the dye.

Although various materials can be considered as the material of the protective film layer PSV2, the transparent electrode ITO2 is formed to finally form the electrode base film of the liquid crystal display device.
For example, it is possible to form a flat surface of 0.2 μm or less, and the adhesiveness to the material of the seal SL (FIG. 7) that adheres the upper and lower electrode substrates (that is, the color filter substrate and the TFT substrate) is good. , LC material to be enclosed LC
Various chemical and physical characteristics such as no influence on (Fig. 7) are required.

In this example, the aminosilane modified epoxy resin described in JP-A-4-96920, a glycidyl ether compound of a novolac resin, a novolac resin and an organic solvent were mixed in a predetermined amount, and a coating of about 2 to 3 μm was used. .

Besides, an epoxy thermosetting resin having good adhesion to glass can also be used. Since this thermosetting resin can set the heat distortion temperature high,
It also improves the heat resistance of the color filter itself, and has sufficient flatness as a base of the transparent electrode ITO2.

Then, (d) a transparent electrode ITO2 is formed on the protective film PSV2 by sputtering, and a pattern is formed using a photolithography process.

In the case of the active matrix type, in the case where the portion where the transparent electrode ITO2 is not formed is hidden in advance by using a frame having an opening in the center and then film formation is performed by sputtering or the like, and pattern formation by photolithography is not performed. There is also.

According to this example, heat resistance is improved to prevent color mixture of dyes, the gap variation between ITO1 and ITO2, which is a transparent electrode for driving liquid crystal in each pixel, is minimized, and optical characteristics are improved. An excellent and highly reliable color liquid crystal display device can be provided.

[0130]

As described above, according to the color liquid crystal display device and the method for manufacturing the same according to the present invention, when the sublimation dye is used to dry-color the dyeing layer, the heat generation temperature of the heating element is controlled. It is possible to increase the color density at a relatively low temperature, and as a result, prevent the thermal transfer film from burning out, prevent the fusion of the sublimable dye, improve the slipperiness between the thermal transfer film and the heating element, and significantly The cost can be reduced by simplifying the manufacturing process.

The optical characteristics of the color filter manufactured according to the present invention are superior to those of the system using a pigment by using a dye, and the film thickness of each pattern portion of the three primary colors is the same. The coating further improves the flatness, and minimizes the variation in the gap between the upper and lower substrates, which is the factor that most affects the optical characteristics of the liquid crystal element when manufacturing the liquid crystal display device.

As a result, variations in optical characteristics such as contrast in the liquid crystal display device can be suppressed.

Further, by forming a dye-proof region between each color pattern of the colored layer to be a color filter and coating each color pattern with a material having good heat resistance,
It is possible to provide a color liquid crystal display device having an excellent function by overcoming the low heat resistance which is a defect of the sublimation dye.

[Brief description of drawings]

FIG. 1 is a diagram showing one example of a method for manufacturing a color liquid crystal display device according to the present invention, in which a voltage characteristic of a heating applied pulse to a heating element and a temperature characteristic and heat generation of the heating element in a coloring step of a dyeing layer for explaining an embodiment. It is explanatory drawing of the positional relationship of a body and a color filter side board | substrate.

FIG. 2 is a graph showing a voltage characteristic of a heating applied pulse to a heating element and a temperature characteristic of the heating element in a coloring step of a dyeing layer for further explaining one example of a method for manufacturing a color liquid crystal display device according to the present invention. It is explanatory drawing of the positional relationship of a heat generating body and a color filter side board | substrate.

FIG. 3 is a diagram showing a voltage characteristic of a heating applied pulse to a heating element and a temperature characteristic of the heating element in a coloring step of a dyeing layer for further explaining one example of a method for manufacturing a color liquid crystal display device according to the present invention. It is explanatory drawing of the positional relationship of a heat generating body and a color filter side board | substrate.

FIG. 4 is a process chart illustrating an example of a method of manufacturing a color film substrate that constitutes a color liquid crystal device according to the present invention.

FIG. 5 is a process drawing for explaining another example of a method for manufacturing a color film substrate that constitutes a color liquid crystal device according to the present invention.

FIG. 6 is an exploded perspective view showing each component of a liquid crystal module adopting a TFT type liquid crystal display device as an example of a color liquid crystal display device to which the present invention is applied.

FIG. 7 is a cross-sectional view of a main part of a liquid crystal element for explaining a structural example of the TFT type liquid crystal display device shown in FIG.

FIG. 8 is a process diagram illustrating a method of manufacturing a color filter substrate using a pigment dispersion method using the most general photolithography process.

9 is a cross-sectional view of a main part for explaining the structure of a general color filter formed by the manufacturing method described in FIG.

FIG. 10 is an explanatory diagram of a thermal transfer system used for color printing.

[Explanation of symbols]

1 Adhesion layer 2 Thermal transfer film 3 Sublimation dye 4 Heating element SHD Shield case (metal frame) LCW Liquid crystal display window PNL Liquid crystal display panel (liquid crystal element) SPB Light diffusion plate MFR Intermediate frame PCB3 Inverter circuit BL backlight BLS backlight Support LCA Lower case MDL Liquid crystal module ITO1, ITO2 Transparent electrodes PSV2, PSV3 Protective film FIL (FIL (R), FIL (G), FIL (B))
Colored layer (color filter) SUB1, SUB2 Glass substrate (substrate) BM Black matrix.

Claims (5)

[Claims] 1. A method for manufacturing a color liquid crystal display device, comprising a liquid crystal layer sandwiched between a pair of substrates including a transparent substrate having a color filter having a color layer pattern of three primary colors formed by a thermal transfer method, A thermal transfer film carrying a sublimation dye is placed on a dyeing layer applied on a substrate, and the sublimation dye is applied to the dyeing layer by heating the thermal transfer film by a heating element that generates heat when an electric pulse is applied. At least including a dyeing step of coloring the dyeing layer, by changing the length of the application time of the electric pulse applied to the heating element in the dyeing step, the coloring density of the dyeing layer. A method for manufacturing a color liquid crystal display device, which comprises adjusting. 2. The dyeing layer according to claim 1, wherein an electric pulse is applied to the heating element for at least a time for obtaining a minimum heat capacity capable of securing an amount of the dye necessary for forming the colored layer. A method for manufacturing a color liquid crystal display device, characterized in that: 3. The method for manufacturing a color liquid crystal display device according to claim 2, wherein the heating element colors the dyeing layer at a temperature equal to or higher than the diffusion start temperature of the dye per one thermal transfer. 4. The method according to claim 1, 2 or 3,
A method of manufacturing a color liquid crystal display device, wherein the thickness of the colored layer is 1 μm or more. 5. The combination according to claim 1, wherein the layer to be colored is a set of yellow, magenta and cyan colors,
Alternatively, there is provided a method of manufacturing a color liquid crystal display device, which is constituted by a combination of red, green and blue.