JP2530440B2 - Method for manufacturing ferroelectric liquid crystal device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a ferroelectric liquid crystal device such as a liquid crystal display device or a liquid crystal-optical shutter array, and more specifically, the initial alignment state of liquid crystal molecules. The present invention relates to a method for manufacturing a ferroelectric liquid crystal device having a color filter with improved display and driving characteristics, which can obtain a uniform monodomain liquid crystal phase having no alignment defects.

[Prior Art] As a conventional liquid crystal element, for example, M. Shut (M.
"Applied Physics Letters" by Schadt and W. Helfrich
Physics Letters ") Volume 18, Issue 4 (Published February 15, 1971), pages 127-128," Voltage Dependant Optical Activity of a Twisted Nematic Liquid Crystal (Physics Letters "). “Voltag
e Dependent Optical Activity of a Twisted Nematic
Liquid crystal ") is known, which uses twisted nematic liquid crystal. This TN liquid crystal is a crosstalk during time-division driving using a matrix electrode structure with high pixel density. However, the number of pixels is limited because of the problem of occurrence of.

Further, a display element of a type in which a switching element formed by a thin film transistor is connected to each pixel and switching is performed for each pixel is known, but a process of forming a thin film transistor on a substrate is extremely complicated, and a large-area display element is required. There are problems that are difficult to create.

To solve these problems, Clark (Cl
ark) et al. in U.S. Pat. No. 4,367,924 propose a ferroelectric liquid crystal device.

FIG. 2 schematically shows an example of a cell for explaining the operation of the ferroelectric liquid crystal. 21a and 21b are In ₂ O ₃ , SnO
₂ or a substrate (glass plate) covered with a transparent electrode made of a thin film such as ITO (Indium Tin Oxide), in which a plurality of liquid crystal molecular layers 22 are oriented so as to be perpendicular to the glass surface.
^* Phase or SmH ^* phase liquid crystal is enclosed. A bold line 23 represents a liquid crystal molecule.
_{Has a} dipole moment ( _P⊥ ) 24 in the direction perpendicular to the molecule. When a voltage above a certain threshold is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is unraveled, and all the dipole moments (P _⊥ ) 24 are oriented in the electric field direction. Can be changed. The liquid crystal molecules 23 have an elongated shape, and exhibit refractive index anisotropy in the major axis direction and the minor axis direction thereof. Therefore, for example, if polarizers arranged in a crossed Nicols position above and below a glass surface are placed. It is easily understood that the liquid crystal optical modulation element has optical characteristics that change depending on the polarity of voltage application.

The liquid crystal cell preferably used in the ferroelectric liquid crystal device of the present invention can be made sufficiently thin (for example, 10 μm or less). As the liquid crystal phase becomes thinner in this way, as shown in FIG. 3, the helical structure of the liquid crystal molecules unravels and becomes a non-helical structure even when no electric field is applied.
The dipole moment Pa or Pb takes either the upward (34a) or downward (34b) state. When an electric field Ea or Eb having a different polarity or more than a certain threshold is applied to such a cell as shown in FIG. 3, the dipole moment becomes
Depending on the electric field vector of Ea or Eb, the direction is changed to the upward 34a or the downward 34b, and the liquid crystal molecules are oriented to either the first stable state 33a or the second stable state 33b accordingly.

As described above, there are two advantages of using such a ferroelectric liquid crystal as an optical modulation element. The first is that the response speed is extremely fast, and the alignment of the second liquid crystal molecules has bistability. The second point will be further explained with reference to FIG. 3, for example. When an electric field Ea is applied, the liquid crystal molecules are aligned in the first stable state 33a, but this state is stable even when the electric field is cut off. When a reverse electric field Eb is applied, the liquid crystal molecules are oriented in the second stable state 33b and the orientation of the molecules is changed. However, even when the electric field is cut off, the liquid crystal molecules remain in this state. Further, as long as the applied electric field Ea does not exceed a certain threshold value, the respective alignment states are maintained. In order to effectively realize such a high response speed and bistability, it is preferable that the cell be as thin as possible.

In order for the ferroelectric liquid crystal element to exhibit a predetermined driving characteristic, the ferroelectric liquid crystal arranged between the pair of parallel substrates is kept between the two stable states regardless of the electric field application state. It is necessary to be in a state of molecular alignment so that the conversion of the For example, for a ferroelectric liquid crystal having a chiral smectic phase, a region (monodomain) is formed in which the liquid crystal molecular layer of the chiral smectic phase is perpendicular to the substrate surface, and thus the liquid crystal molecular axis is arranged almost parallel to the substrate surface. Need to be However, in the conventional ferroelectric liquid crystal element, the alignment state of the liquid crystal having such a monodomain structure was not always formed satisfactorily, and therefore, the actual condition was that sufficient characteristics were not obtained.

FIG. 4 is a sectional view of a conventional ferroelectric liquid crystal device.
FIG. 5 is a schematic explanatory view showing a state of alignment defects appearing in a conventional ferroelectric liquid crystal device.

That is, the conventional ferroelectric liquid crystal element 40 shown in FIG.
Has a pair of parallel substrates 41 and 42, and the substrates 41 and 42 are provided with striped transparent electrodes 43 and 44 forming a matrix electrode structure, respectively.

Generally, a color filter is composed of red (R), green (G), and blue (B) dyes or a layer containing the dyes. However, since the film thickness of each dye layer is different regardless of the forming method, 2000Å A step A of about 1 μm is formed. As a result, when the alignment control is performed by utilizing the temperature lowering process, the above-mentioned step A causes the alignment defect in the ferroelectric liquid crystal 47 with the step A as a boundary. Also, this step A
On the substrates 41 and 42 on which the alignment control films 45 and 46 respectively exist.
Is provided, a step C formed in accordance with the step A also occurs in the alignment control film with almost the thickness of the pixel, and an alignment defect occurs in the ferroelectric liquid crystal 47 in the same manner as described above.

FIG. 5 is a sketch of the ferroelectric liquid crystal device observed with a crossed Nicols polarization microscope. White lines 51 in the drawing correspond to the lines of the spacer (not shown) used for the liquid crystal device, and the line 52 And 53 are observed corresponding to the step C on the substrate 41 in FIG. The portion 54 in the figure is a ferroelectric liquid crystal sandwiched between the counter electrodes. A large number of edge lines 55 appearing in the polarizing microscope represent alignment defects of the ferroelectric liquid crystal.

If there is a step of 1000 Å or more on the surface in contact with the ferroelectric liquid crystal as described above, an alignment defect is generated from the step and the monodomain formation of the ferroelectric liquid crystal is disturbed.

[Problems to be Solved by the Invention] The present inventors have clarified through experiments that such a step on the substrate causes an alignment defect with respect to the ferroelectric liquid crystal.

An object of the present invention is to provide a method for manufacturing a ferroelectric liquid crystal device, which can prevent the occurrence of the above-mentioned alignment defects and can sufficiently exhibit the high-speed response and the memory effect characteristics originally possessed by the ferroelectric liquid crystal device. To do.

[Means for Solving Problems] The inventors of the present invention have focused on the initial orientation in the temperature decreasing process in which the ferroelectric liquid crystal transitions from the isotropic phase (high temperature state) to the liquid crystal phase (low temperature state). The present inventors have found a ferroelectric liquid crystal device having a structure capable of satisfying both the operating characteristics of the device based on the bistability of the dielectric liquid crystal and the monodomain property of the liquid crystal layer.

The liquid crystal element of the present invention is based on such findings, and more specifically, there is no step on the surface in contact with the liquid crystal layer,
In other words, it is characterized in that the initial alignment property in the temperature lowering process is made good by preventing abrupt changes in the film thickness of the liquid crystal layer, and a monodomain without alignment defects is formed.

That is, according to the present invention, a ferroelectric liquid crystal is sandwiched between a pair of parallel substrates on which transparent electrodes are formed, and a color filter for each pixel is formed flat at least between one transparent electrode and the substrate without any gap. In the method for producing an organic liquid crystal element, (a) a low-temperature-curable polyamino-based resin having a photosensitive group in its molecule is provided on the substrate with a coloring material having a low transmittance for light having a photosensitive wavelength. A dispersed first color resin film is formed, and the first color resin film is exposed to light having a photosensitive wavelength through a mask and developed to form a patterned first color resin layer. A first step, and (b) dispersing a coloring material having a low transmittance for light having a photosensitive wavelength of the resin in the low-temperature-curable polyamino resin on the substrate on which the first coloring resin layer is formed. Forming a second colored resin film The colored resin film is exposed to light of a photosensitive wavelength through a mask and the substrate in a region where the first colored resin layer and the second colored resin layer are to be formed, and is developed, whereby the patterned second colored film is formed. A second step of forming a resin layer, and (c) the low temperature curable polyamino resin on the substrate on which the first and second colored resin layers are formed, with respect to the photosensitive wavelength light of the resin. By forming a third colored resin film in which a colored material having a transmission characteristic is dispersed, exposing the photosensitive resin to light having a photosensitive wavelength through a substrate without developing a mask, and developing the third colored resin film. , Patterned third
And a third step of forming the colored resin layer of (1), and the colored layer of each pixel of the color filter is formed flat with no gaps by the method of manufacturing a ferroelectric liquid crystal element.

 Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the basic structure of a ferroelectric liquid crystal element produced by the manufacturing method of the present invention. In FIG. 1, a ferroelectric liquid crystal element 1 has substrates 2 and 3 using transparent plates such as glass plates or plastic plates, and a ferroelectric liquid crystal 4 is sandwiched between them. On each of the substrates 2 and 3, there are disposed transparent electrodes 5 and 6 in the form of stripes forming a matrix electrode structure. On the transparent electrodes, alignment control films 7 and 8 are formed. R (red), G
The (green) and B (blue) color filters are formed to have substantially equal film thicknesses.

In the substrate having the above structure, the step due to the thickness of the color filter and the gap between the pixels is corrected,
Even if the transparent electrode and the alignment control film are sequentially formed on the pixel, the substrate surface can be kept substantially flat.

In the present invention, the step of the color filter substrate can be set to 1000 Å or less by the above-mentioned flattening, but it is preferably set to 500 Å or less. This step is 1000Å
Above this, the liquid crystal element using the non-planarizing layer formed to have a thickness of 1200 Å or more, in particular, will have the edge defect of the edge line shown in FIG.

Next, a method for producing the color filter used in the present invention will be described with reference to the drawings.

6 (a) to 6 (g) are process charts showing a typical aspect of the process of forming a color pixel of the present invention. .

First, as shown in FIG. 6 (a), a low-temperature curable polyamino-based resin (hereinafter referred to as a photosensitive polyamino-based resin) having a monochromatic photosensitive group in its molecule is formed on a substrate 61. A patterned first colored resin layer 62 of a colored resin is formed by dispersing a colored material having a low transmittance for the photosensitive wavelength light of the photosensitive polyamino resin. The photosensitive wavelength of the colored resin is 450 nm or less, and any colored resin film having a low light transmittance of 450 nm or more may be used.

Hereinafter, a method for forming the patterned first colored resin layer 62 shown in FIG. 6 (a) to which the present invention is applied will be described. A photosensitive polyamino resin liquid (NMP solution) in which a predetermined amount of a coloring material having a spectral characteristic of a photosensitive polyamino resin having a low transmittance for light having a photosensitive wavelength is mixed on a substrate 61.
The colored resin film of the first color is applied and formed on a predetermined substrate 61 with a spinner so as to have a predetermined film thickness, and prebaked under an appropriate temperature condition. Then, with light having the sensitivity of the photosensitive colored resin (for example, a high pressure mercury lamp),
The colored resin film is exposed through a photomask having a predetermined pattern shape corresponding to the pattern to be formed,
Light curing of the pattern part is performed.

Then, the colored resin film having a photo-cured portion is ultrasonically developed with a solvent that dissolves only the unexposed portion (for example, a solvent containing N-methyl-2-pyrrolidone-based solvent as a main component) and then rinsed. (Eg 1,1,1-trichloroethane etc.). Then, a post-baking process is performed to form a patterned first colored resin layer 62 as shown in FIG. 6 (a).

The substrate on which the first colored resin layer 62 having a low transmittance for the photosensitive wavelength light of the colored resin thus formed is formed.
61, and then, as shown in FIG. 6 (b), a photosensitive polyamino compound containing a predetermined amount of a coloring material having a spectral characteristic of the photosensitive polyamino resin having a low transmittance with respect to light having a photosensitive wavelength. Using a resin solution (NMP solution), a second colored resin film 63 'is formed on a predetermined substrate 61 using a spinner so as to have a predetermined film thickness, and prebaked under appropriate temperature conditions. To do.

Then, as shown in FIG. 6 (c), a predetermined pattern shape corresponding to the pattern to be formed is formed from the substrate 61 side by using a photosensitive wavelength light 65 (for example, a high pressure mercury lamp) having the sensitivity of the photosensitive coloring resin. The colored resin film 63 ′ is exposed through the photomask 64 that it has, and the pattern portion is photocured.

Then, the colored resin film 63 'having a photo-cured portion is ultrasonically developed with a solvent that dissolves only the unexposed portion (for example, a solvent containing N-methyl-2-pyrrolidone-based solvent as a main component) by ultrasonic wave, Rinse treatment (for example, 1,1,1-trichloroethane or the like) is performed. Then, post bake treatment is performed,
Patterned second colored resin layer 63 as shown in FIG. 6 (d).
Is formed.

The first and second colored resin layers 62 and 63 of two colors, which are formed in this way and have a low transmittance for the light of the photosensitive wavelength,
Next, as shown in FIG. 6 (e), a photosensitive polyamino resin containing a predetermined amount of a coloring material having a transmission characteristic for the photosensitive wavelength light of the photosensitive polyamino resin is formed on the substrate 61 on which the film is formed. Using a resin solution (NMP solution), a third colored resin film 66 'is formed on a predetermined substrate 61 by a spinner so as to have a predetermined film thickness, and prebaked under appropriate temperature conditions. To do. Then, as shown in FIG. 6 (f),
Sensitive wavelength light having the sensitivity of the photosensitive colored resin from the substrate 61 side
65 (for example, a high-pressure mercury lamp), expose the colored resin film,
Light curing of the pattern part is performed.

Then, the colored resin film 66 'on which the photo-cured portion is formed,
A solvent that dissolves only the unexposed portion (for example, N-methyl-
After ultrasonic development using a 2-pyrrolidone-based solvent or the like as a main component, a rinse treatment (for example, 1,1,1-trichloroethane or the like) is performed. Next, a post-baking treatment is performed to form a patterned third colored resin layer 66 as shown in FIG. 6 (g).

Through the above steps, a color filter having no gaps between the colored resin layers is formed as shown in FIG. 6 (g). Since the first and second colored resin layers have low transmittance of the resin to the photosensitive wavelength light, it is possible to perform light exposure that allows the colored resin film in an unnecessary portion to be dissolved and removed by development. .

As described above, the method for producing the color filter shown in FIGS. 6 (a) to 6 (g) describes only the steps essential for carrying out the method of the present invention. Can be added.

The photosensitive polyamino-based resin forming the colored resin layer having the color filter in the present invention, a cured film obtained at 200 ℃ or less, for example, a cured film can be formed by heat of about 150 ℃ × 30 minutes, for example, Aromatic polyamide resins and polyimide resins that have a photosensitive group in their molecule, especially those that do not have specific light absorption properties in the visible light wavelength range (400 to 700 nm) (light transmittance of about 90% or more) Thing)
Is preferred. In this respect, an aromatic polyamide resin is particularly preferable.

The photosensitive group in the present invention may be any aromatic chain having a photosensitive hydrocarbon unsaturated group as shown below, for example: (1) benzoic esters (Wherein R ₁ is CHX = CY-COO-Z-, X is -H or -C ₆ H ₅ ,
Y is -H or -CH _3, Z is - or an ethyl group or a glycidyl group) (2) Benzyl acrylate (Wherein, Y represents —H or CH ₃ ) (3) Diphenyl ethers (Wherein R ₂ is _{CHX = CY-CONH-, CH 2} = CY-COO- (CH 2) 2
-OCO or CH ₂ = containing one or more CY-COO-CH _2- , X,
(Y represents the above meaning) (4) Chalcones and other compound chains (Wherein R ₃ represents H-, an alkyl group or an alkoxy group) Etc.

Specific examples of aromatic polyamide resins and polyimide resins having these groups in the molecule are lysocoat PA-
Examples include 1000 (manufactured by Ube Industries, Ltd.) and Lithocoat PI-400 (manufactured by Ube Industries, Ltd.).

In general, the photosensitive resin used in the photolithography process varies depending on its chemical structure, but few of them have excellent durability such as heat resistance, light resistance and solvent resistance as well as mechanical properties. On the other hand, the above-mentioned photosensitive polyamino resin of the present invention is a resin system having excellent durability in terms of chemical structure as well, and the color filter formed by using them also has very good durability. Becomes

The coloring material forming the colored resin layer of the color filter in the present invention is not particularly limited as long as it can obtain desired spectral characteristics among organic pigments, inorganic pigments, dyes and the like. In this case, each material can be used alone or as a mixture of some of them. However, when using a dye,
Although the performance of the color filter is governed by the durability of the dye itself, use of the resin system of the present invention makes it possible to form a dye having excellent performance as compared with an ordinary dyed color filter. Therefore, an organic pigment is most preferable as the coloring material in consideration of the color characteristics and various performances of the color filter.

Organic pigments include azo pigments such as soluble azo pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, and indigo pigments, anthraquinone pigments, perylene pigments, perinone pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments. A condensed polycyclic pigment containing a pigment, a phthalone pigment, a methine / azomethine pigment, a metal complex pigment, or a mixture of some of these pigments is used.

In the present invention, the colored resin used to form the colored resin layer is prepared by blending the photosensitive polyamino resin solution with the coloring material having the desired spectral characteristics in a proportion of about 10 to 50% by ultrasonic waves or After sufficiently dispersing with a triple roll or the like, a filter having a large particle size is removed to prepare.

The colored resin layer of the color filter in the present invention is formed by applying the colored resin on a substrate by a coating device such as a spinner or a roll coater, and forming it in a pattern by a photolithography process, the layer thickness of which has a desired spectral characteristic. However, it is usually 0.5 to 5 μm, preferably 1 to 2 μm.

Although the colored resin layer of the color filter of the present invention is composed of a good material having sufficient durability itself, in particular, in order to protect the colored resin layer from various environmental conditions, , Organic resin such as polyamide, polyimide, polyurethane, polycarbonate, silicon-based resin or Si ₃ N ₄ , SiO ₂ , SiO, Al ₂ O ₃ , T on the surface of the colored resin layer.
An inorganic film such as a ₂ O ₃ can be provided as a protective film by spin coating, roll coating, or vapor deposition. Further, the film thickness of the protective film 9 can determine the film thickness of the ferroelectric liquid crystal 4, and therefore varies depending on the type of liquid crystal material, the required response speed, etc. It is set to 20 μ, preferably 0.5 μ to 10 μ.

Examples of the material of the alignment control film used in the present invention include polyvinyl alcohol, polyimide, polyamideimide, polyester, polycarbonate, pyrivinylacetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose resin, melamine resin, and urea. Resins such as resin and acrylic resin, photosensitive polyimide, photosensitive polyamide, cyclic rubber photoresist, phenol novolac photoresist or electron beam photoresist (polymethylmethacrylate, epoxidized-1,4-polybutadiene, etc.), etc. It can be selected and formed. The orientation control film 7 generally depends on the film thickness of the ferroelectric liquid crystal, but is generally 10Å to 1 μ,
It is preferably set in the range of 100Å to 3000Å.

A particularly suitable liquid crystal material for use in the present invention is a liquid crystal having bistability and having ferroelectricity. Specifically, the chiral smectic C phase (SmC
^* ), H phase (SmH ^* ), I phase (SmI ^* ), J phase (SmJ ^* ), K phase (S
Liquid crystals of mK ^* ), G phase (SmG ^* ) or F phase (SmF ^* ) can be used.

For this ferroelectric liquid crystal,
De Physique Le Terreq ”(“ LE JOURNAL DE PHYSIQ
UE LETTRES ") 1975, 36 (L-69)," Ferroelectric Liquid Crystals "(" Ferroelect
ric Liquid Crystals ”);“ Applied Physics Letters ”1980
Year 36 (11), "Submicro Second Bistable Electro-Optic Switching In Liquid Crystals"("Submicro Second Bistable
Electrooptic Switching in Liquid Crystals ");
"Solid State Physics", 1981 16 (141), "Liquid Crystal", etc., and the ferroelectric liquid crystals disclosed therein can be used in the present invention.

Specific examples of the ferroelectric liquid crystal include, for example, desiloxybenzylidene-p'-amino-2-methylbutyl cinnamate (DOBAMBC), hexyloxybenzylidene-p '.
-Amino-2-chloropropyl cinnamate (HOBACP
C), 4-o- (2-methyl) -butylresorcylidene-4′-octylaniline (MBRA8).

When an element is formed using these materials, since the liquid crystal compound is maintained in a temperature state in which it becomes a chiral smectic phase, the element can be supported by a block or the like in which a heater is embedded, if necessary.

[Operation] In the method for manufacturing a ferroelectric liquid crystal device according to the present invention, the first and second colored resin layers are colored by dispersing a coloring material of the photosensitive polyamino-based resin having a low transmittance for light having a photosensitive wavelength. Since the resin film is formed in a pattern by the photolithography process, it is possible to perform light exposure that can easily dissolve and remove the coloring resin film in an unnecessary portion by development. Then, the third coloring resin layer is formed into a photosensitive polyamino-based resin layer. Since the colored resin film having a transmission characteristic for the light of the photosensitive wavelength of the resin is formed by the photolithography process, it is possible to form a flat color filter on the substrate with no gaps between pixels.

In addition, the substrate having the color filter produced by the present invention has good flatness, and the liquid crystal phase sandwiched between the substrates having good flatness is gradually changed from the isotropic phase to the liquid crystal phase in the temperature decreasing process. By cooling, the liquid crystal phase region gradually expands to form a uniform monodomain liquid crystal phase.

For example, the above-mentioned DOBA showing a ferroelectric liquid crystal phase as a liquid crystal.
Explaining MBC as an example, smectic A phase (SmA phase) at about 115 ° C when gradually cooling from the isotropic phase of DOBAMBC
Phase transition to. At this time, rubbing or SiO _{2 on the} substrate
When the alignment treatment such as oblique vapor deposition is performed, a monodomain in which the molecular axes of liquid crystal molecules are parallel to the substrate and aligned in one direction is formed. Further, as the cooling is further advanced, a phase transition to a chiral smectic C phase (SmC ^* phase) occurs at a specific temperature of about 90 to 75 ° C. depending on the thickness of the liquid crystal layer. If the thickness of the liquid crystal layer is about 2 μm or less, SmC ^*
The phase spiral unravels and exhibits bistability.

[Examples] Hereinafter, the present invention will be described more specifically with reference to Examples.

Example 1 By the steps shown in FIGS. 6A to 6G, R,
G and B three color pixels were formed.

First, a green colored resin material [Lionol Green 6Y] is formed on Corning's # 7059 glass substrate 61.
K (trade name, manufactured by Toyo Ink Co., CI No. 74265) is PA-1000
C (Product name, Ube Industries, Polymer content = 10%, Solvent: N
-Methyl-2-pyrrolidone, pigment: polymer = 1: 2 blended) to prepare a photosensitive colored resin material] and applied to a film thickness of 2.0 μm by a spinner coating method.

Next, the colored resin film was prebaked at 80 ° C. for 30 minutes, and then exposed with g-line (λ = 4358Å) through a pattern mask corresponding to the pattern shape to be formed.

After completion of the exposure, development is carried out using ultrasonic waves with a dedicated developing solution (developing solution containing N-methyl-2-pyrrolidone as a main component) that dissolves only the unexposed portion of the colored resin film, and a dedicated rinsing solution ( Rinse solution containing 1,1,1-trichloroethane as the main component)
Then, post-baking was performed at 150 ° C. for 30 minutes to form a green colored resin layer 62 having a pattern shape. (See FIG. 6 (a)) Next, on the substrate 61 on which the patterned green colored resin layer 62 is formed, as a second color, a red colored resin material [Irgazin Red BPT (trade name) is used. , Ciba-Geigy, CI No. 71127) PA-1000C
(Product name, manufactured by Ube Industries, Polymer content = 10%, solvent: N-
Methyl-2-pyrrolidone, pigment: polymer = 1: 2 blended)
The photosensitive colored resin material prepared by being dispersed in a coating solution] was applied to a film thickness of 2.0 μm by a spinner coating method. (See FIG. 6 (b)) Next, after prebaking the colored resin layer at 80 ° C. for 30 minutes, the g-line is applied from the substrate 61 side through a pattern mask 64 corresponding to the pattern shape to be formed. (Λ = 4358
Å) Exposed at 65.

After completion of the exposure, development is carried out using ultrasonic waves with a dedicated developing solution (developing solution containing N-methyl-2-pyrrolidone as a main component) that dissolves only the unexposed portion of the colored resin film, and a dedicated rinsing solution ( Rinse solution containing 1,1,1-trichloroethane as the main component)
Then, post-baking was performed at 150 ° C. for 30 minutes to form a red colored resin layer 63 having a pattern shape. (See FIG. 6 (d)) Further, in this way, the two colored resin patterns 62, 63 are formed.
A blue colored resin material [Heliogen Blue L7080 (trade name, manufactured by BASF Corp., C.
I. No.74160) was dispersed in PA-1000C (trade name, manufactured by Ube Industries, Ltd., polymer content = 10%, solvent: N-methyl-2-pyrrolidone, pigment: polymer = 1: 2 blended) to prepare a photosensitive film. Blue resin material] was applied to a film thickness of 2 μm by a spinner coating method. (See FIG. 6 (e)) Next, after prebaking the colored resin layer at 80 ° C. for 30 minutes, the entire surface was exposed from the side of the substrate 61 with the g-line (λ = 4358Å). (See FIG. 6 (f)) After the exposure, ultrasonic waves are used in a dedicated developer (a developer containing N-methyl-2-pyrrolidone as a main component) that dissolves only the unexposed portion of the colored resin film. And develop it, and then use a special rinse solution (rinse solution containing 1,1,1-trichloroethane as the main component)
Then, post-baking was performed at 150 ° C. for 30 minutes to form a blue colored resin layer 66 having a pattern shape.

In this way, there is no gap between the colored resin patterns on the substrate 61, and the color filters 6 of three colors having the same film thickness are formed.
2,63,66 could be formed. (See FIG. 6 (g)) Next, a negative resist (ODUR; made by Tokyo Ohka) was applied and formed on the formed color filter as the protective film 9 in FIG.

Further, as shown in FIG. 1, ITO was formed into a film with a thickness of 500 Å by a sputtering method to form a transparent electrode 5. As the orientation control film 7, a polyimide forming solution (Hitachi Chemical Industries "PIQ") was applied by a spinner rotating at 3000 rpm and heated at 150 ° C. for 30 minutes to form a 2000 Å polyimide film. Then, the surface of this polyimide coating film was rubbed.

The color filter substrate thus formed and the opposing substrate 3 were attached to each other to form a cell, and the ferroelectric liquid crystal was injected and sealed to obtain a liquid crystal element. Observation of this liquid crystal element with a crossed Nicol polarizing microscope confirmed that no liquid crystal molecules had any alignment defects.

[Effects of the Invention] As described above, according to the present invention, it is possible to prevent the occurrence of alignment defects by forming a flat color filter having no gaps between pixels on a substrate, and to improve the ferroelectricity. It is possible to provide a ferroelectric liquid crystal element that can sufficiently exhibit the characteristics of liquid crystal.

[Brief description of drawings]

FIG. 1 is a sectional view showing the basic structure of a ferroelectric liquid crystal element produced by the manufacturing method of the present invention, and FIGS. 2 and 3 are perspective views schematically showing the ferroelectric liquid crystal used in the present invention. FIG. 4 is a cross-sectional view of a conventional ferroelectric liquid crystal device, FIG. 5 is a schematic explanatory view showing the state of alignment defects appearing in the conventional ferroelectric liquid crystal device, and FIGS. 6 (a) to 6 (g). FIG. 6A is a process diagram showing a process of forming a color pixel of the present invention. 1 …… Ferroelectric liquid crystal element 2,3,61 …… Substrate 4 …… Ferroelectric liquid crystal 5,6 …… Transparent electrode 7,8 …… Alignment control film 9 …… Protective film 62,63,66 …… Colored resin layer 63 ′, 66 ′ …… Colored resin film 64 …… Photomask 65 …… Sensitive wavelength light

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Miki Tamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Nobuyuki Sekimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (56) References JP-A-60-237441 (JP, A)

Claims (2)

(57) [Claims] 1. A ferroelectric liquid crystal in which a ferroelectric liquid crystal is sandwiched between a pair of parallel substrates on which transparent electrodes are formed, and a color filter of each pixel is formed flat without any gap between at least one transparent electrode and the substrate. In the method for producing a liquid crystal element, (a) a coloring material having a low transmittance for the photosensitive wavelength light of the resin is dispersed in a low temperature curable polyamino resin having a photosensitive group in the molecule on the substrate. Forming a first colored resin layer, and exposing the first colored resin film to light having a photosensitive wavelength through a mask and developing the first colored resin film to form a patterned first colored resin layer. 1), and (b) disperse on the substrate on which the first colored resin layer is formed a coloring material having a low transmittance for the photosensitive wavelength light of the resin in the low temperature curable polyamino resin. To form a second colored resin film The patterned second colored resin is formed by exposing the oil film to light having a photosensitive wavelength through a mask and the substrate in a region where the first colored resin layer and the second colored resin layer are formed and developing the same. A second step of forming a layer, and (c) the low-temperature curable polyamino resin on the substrate on which the first and second colored resin layers are formed transmits the photosensitive wavelength light of the resin. By forming a third colored resin film in which a colored material having characteristics is dispersed, exposing the third colored resin film to light having a photosensitive wavelength through a substrate without passing through a mask, and developing the film, Patterned third
And a third step of forming the colored resin layer, and the colored layer of each pixel of the color filter is formed flat without gaps by the method of manufacturing a ferroelectric liquid crystal element. 2. The coloring material having a low transmittance for the photosensitive wavelength light is a green coloring material or a red coloring material, and the coloring material having a transmission characteristic for the photosensitive wavelength light is a blue coloring material. 2. A method of manufacturing a ferroelectric liquid crystal device according to item 1 above.