JPH06324340A - Production of ferroelectric liquid crystal element - Google Patents

Abstract

PURPOSE:To produce a ferroelectric liquid crystal element without orientation defect. CONSTITUTION:Transparent electrodes 12a, 12b and orientation controlling layers 14a, 14b are formed on glass substrates 11a, 11b, respectively, and the orientation controlling layers 14a, 14b are treated by rubbing. The glass substrates 11a, 11b are cleaned and dried at low temp. as <100 deg.C. Further, these glass substrates 11a, 11b are sealed with a UV-curing sealing agent at low temp. (<100 deg.C), and a ferroelectric liquid crystal is injected at low temp. as <100 deg.C.

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 ferroelectric liquid crystal device, and more particularly to a method of manufacturing a ferroelectric liquid crystal in which alignment defects are prevented from occurring.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal device of a type in which transmitted light rays are controlled by combining with a polarizer by utilizing a refractive index anisotropy of a ferroelectric liquid crystal has been proposed by Clark and Lagerwall. (JP-A-56-107216, U.S. Pat. No. 436).
7924 specification). This ferroelectric liquid crystal has bistability and generally has a non-helical chiral smectic C phase (SmC ^* ) or chiral smectic H phase (SmH ^* ) in a specific temperature region. Then, when an electric field is applied to the ferroelectric liquid crystal, the liquid crystal molecules exhibit an alignment state corresponding to the electric field vector.
However, the transition between the states does not occur continuously but changes intermittently with a predetermined threshold value. As a result, two optically stable states (bistability), which are the first optically stable state and the second optically stable state, appear. Further, since the above-mentioned optically stable state is also a thermodynamically stable state, energy is required for transition between the states, so that the alignment state during electric field application is maintained even after the electric field is applied (memory characteristic).
There is a characteristic. Furthermore, since it responds quickly to changes in the electric field and has a wide viewing angle, it is expected to be applied to a large-sized liquid crystal element that can operate at high speed.

[0003]

However, the liquid crystal element using the ferroelectric liquid crystal has a drawback that an alignment defect is likely to occur, and this defect appears as a decrease in contrast or display unevenness. That is, the orientation including the chevron structure of the smectic phase is 2 in C1 and C2 as shown in FIG.
It can be explained by different types of orientation models. In FIG. 3, reference numeral 31 indicates a smectic layer, reference numeral 32 indicates a C1 oriented region, and reference numeral 33 indicates a C2 oriented region. Smectic liquid crystals generally have a layered structure, but S
When the transition from the A phase to the SC phase or the SC * phase occurs, the phase interval shrinks, so that the layer has a bent structure (chevron structure) at the center of the upper and lower substrates 11a and 11b as shown in FIG. As shown in the figure, there may be two bending directions, C1 and C2, but as is well known, the liquid crystal molecules at the substrate interface form an angle with the substrate by rubbing (as described above, the alignment film interface of the substrate becomes The angle formed by the liquid crystal and the liquid crystal is referred to as a "pretilt angle"), and the direction is a direction in which the liquid crystal molecules lift their heads toward the rubbing direction A (the tip becomes floating). Due to this pretilt, the C1 orientation and the C2 orientation are not elastically energy-equivalent, and a transition occurs at a certain temperature as described above. In addition, mechanical strain may cause dislocation. When the layered structure of FIG. 3 is viewed in plan, the boundary 34 when the C1 orientation is changed to the C2 orientation in the rubbing direction A
Is a zigzag lightning bolt and is called a lightning defect.
Boundary 35 from transitioning from C1 to C1 has a wide, gentle curve and is called a hairpin defect.

The presence or absence of such defects depends on the pretilt angle α of the alignment state of the liquid crystal element using the ferroelectric liquid crystal.
When the pretilt angle α is large (specifically α ≧ 10 °), a good alignment state without alignment defects can be obtained. That is, the above-mentioned C1 orientation state has four orientation states and is different from the conventional C1 orientation state. Among them, two of the four C1 orientation states are bistable states (uniform states). Is forming. Here, if the apparent tilt angle in the absence of an electric field is θa, of the four states in the C1 orientation state, the state showing the relationship of two expressions is called the uniform state.

.THETA.>. THETA.a> .THETA. / 2 Equation 2 In the uniform state, it is considered that the director is not twisted between the upper and lower substrates in view of its optical properties. FIG. 4A is a schematic view showing the arrangement of directors at respective positions between the substrates in each state of C1 orientation. 5 in the figure
1 to 54 show the state in which the director is projected on the bottom surface of the cone in each state and viewed from the bottom surface, 51 and 52 are the spraying state, and 53 and 54 are the arrangement of the directors considered to be the uniform state. As can be seen from the figure, in the two states 53 and 54 of the uniform, the positions of the liquid crystal molecules at either the upper or lower substrate interface are replaced with the positions in the splay state. FIG. 4B shows the C2 orientation, and there are two states 55 and 56 due to internal switching without interface switching. The uniform state of the C1 orientation produces a larger tilt angle θa than the conventionally used bistable state of the C2 orientation, and the luminance is large and the contrast is high.

However, it has been difficult to stably manufacture a liquid crystal device having such a large pretilt angle (α ≧ 10 °) because its alignment state changes depending on the number of manufacturing processes and the manufacturing process.

[0007] Therefore, an object of the present invention is to provide a ferroelectric liquid crystal device which stably achieves a good alignment state and has a high display quality.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the first invention is to wash and dry a substrate on which an electrode and an uniaxially oriented alignment film are formed. A first step of curing, a second step of bonding the cleaned and dried pair of substrates with a seal member and then curing the seal member, and degassing between the pair of substrates sealed by the seal member. Third, after injecting ferroelectric liquid crystal
In the method for manufacturing a ferroelectric liquid crystal device, which comprises the steps of
It is characterized in that it is carried out at a temperature of 00 ° C. or lower.

In this case, it is preferable that the uniaxial alignment treatment is performed so that the angle between the interface of the alignment film and the ferroelectric liquid crystal is 10 ° or more.

Further, the uniaxial orientation treatment may be performed by rubbing a polymer thin film.

Further, the uniaxial orientation treatments at the upper and lower interfaces of the substrate intersect, and the intersection angle θ _c is 20 °>
It may be that θ _c > 0 °.

On the other hand, a second aspect of the present invention is the first step of cleaning and drying a substrate on which an electrode and an alignment film subjected to uniaxial alignment treatment are formed, and a ferroelectric liquid crystal between a pair of bonded substrates. And a third step of injecting a ferroelectric liquid crystal in the third step, after the uniaxial alignment treatment in the first step. When the time of heating to 100 ° C. or higher is set to t1 and the time of heating to 80 ° C. or higher after injecting the liquid crystal is set to t2, the relationship of 2t1> t2 ≧ t1 is established. .

In this case, it is preferable that the heat history applied after the uniaxial alignment treatment and before the liquid crystal is injected is approximately equal to the heat history applied after the liquid crystal is injected.

Further, the uniaxial orientation treatment may be performed by rubbing a polymer thin film.

Furthermore, the uniaxial orientation treatments at the upper and lower interfaces of the substrate intersect, and the intersection angle θ _c is 20 °.
> Θ _c > 0 ° may be set.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

First, the structure of the liquid crystal element will be described with reference to FIG.

As shown in FIG. 1, the liquid crystal element includes a pair of upper and lower substrates 11a and 11b arranged in parallel, and each of the substrates 11a and 11b has a thickness of about 4 mm.
00-3000Å transparent electrodes 12a, 12b are formed. Further, on these transparent electrodes 12a, 12b, insulating films 13a, 13b having a thickness of 100-3000Å are formed.
Is formed, and on the insulating films 13a and 13b, an alignment control layer (alignment film) 1 having a thickness of 50 to 1000 Å is formed.
4a and 14b are formed. The ferroelectric liquid crystal 15 is arranged between the upper substrate 11a and the lower substrate 11b. In addition, the above-mentioned insulating films 13a and 13b
May be a coating and baking type inorganic oxide, a sputtered film, or a multilayer film composed of two or more layers. A high molecular polymer is usually used for the orientation control layers 14a and 14b, but when it is necessary to give a large pretilt angle as in the present invention, it is preferable to use a fluorine-containing polyimide or the like. The value of the pretilt angle is preferably 10 to 30 °. As the uniaxial orientation treatment method, a method of rubbing a polymer, which is usually a polymer thin film, is used. In addition, when rubbing the upper and lower substrates 11a and 11b, the upper and lower rubbing directions can intersect in the range of 0-20 °. As a result, the uniform states 53 and 54 described above can be stabilized, and higher contrast can be obtained. In the present invention, a ferroelectric liquid crystal 15 having a chiral smectic phase state can be used. Specifically, the chiral smectic C phase (Sm * C), H
Phase (Sm * H), I phase (Sm * I), K phase (Sm * K)
Alternatively, a G-phase (Sm * G) liquid crystal can be used. As a particularly preferable liquid crystal, a liquid crystal exhibiting a cholesteric phase on the high temperature side can be used, and for example, a pyrimidine-based mixed liquid crystal exhibiting the phase transition temperature and the physical property values described below can be used.

Pyrimidine liquid crystal A

[0020]

[Outer 1] Cone angle Θ = 14 ° (30 ° C.) Layer inclination angle δ = 11 ° (〃) Apparent tilt angle θa = 11.5 ° (〃) In this embodiment, the pretilt angle α is 10 ° or more. A ferroelectric liquid crystal device was manufactured by performing uniaxial alignment treatment so that the heat history from the uniaxial alignment treatment to the liquid crystal injection was suppressed to 100 ° C. or less.

As a result, the pretilt angle α of the manufactured liquid crystal element is maintained at 10 ° or more, and a stable large pretilt angle can be achieved. Then, it is possible to stably create a good uniform alignment state without alignment defects such as zigzag defects. Hereinafter, an experiment conducted by the present inventor to confirm the effect will be described.

The glass substrates 11a and 11b used in this experiment
Has a size of 7.5 cm × 7.5 cm, and the transparent electrodes 12a and 12b are formed on the surfaces of the substrates 11a and 11b. Further, a thin film of tantalum oxide (insulating films 13a and 13b) is formed on the transparent electrodes 12a and 12b by a sputtering method, and a 1% NMP solution of fluorine-based polyimide is further applied thereon by a spinner 270. The alignment control layers 14a and 14b were formed by firing at 1 ° C. for 1 hour. next,
The substrates 11a and 11b were rubbed to set the pretilt angle α to 10 ° or more. Further, the rubbing directions are twisted in the clockwise direction when viewed from above the cell from the same direction and parallel to each other, so that the crossing angle θ _c between them is 10 ° and the cell thickness of 1.5 μm is maintained. , 11
A cell was created by bonding b. In the step of washing and drying the cell after rubbing (first step), IPA (isopropyl alcohol) was used as the washing liquid so that the drying could be performed at a low temperature (80 ° C.). In addition, in the step of bonding the upper and lower substrates 11a and 11b (second step), a UV curing seal is used as a seal member so that it can be cured by UV light and heat history is not added.

Five cells were prepared by such a method, and four cells among them were set at 80 ° C., 100 ° C., 120 ° C., 1
Heat treatment was performed at 50 ° C. for 6 hours. The remaining one cell was not heat-treated. Further, in the step (third step) of injecting the liquid crystal between the substrates 11a and 11b bonded by the UV curing seal, first, the substrates 11a and 11b are deaerated, and then phenylpyrimidine is used as a main component. Ferroelectric liquid crystal having a cone angle of 14 ° (however, room temperature) was injected at a low temperature of 85 ° C. Further, after the injection, the chiral smectic C phase was gradually cooled.

The phase transition temperature of the ferroelectric liquid crystal is as follows.

[0025]

[Outside 2] A liquid crystal element was prepared in this manner, and the alignment state of the liquid crystal was examined in each of the following four cases.

1. Orientation state before driving 2. Alignment state when driven at a driving voltage of 25V at 2.15 ° C. 3.30 ° C.-4.45 ° C. Note that the driving voltage used has the waveform shown in FIG. 2 (b). That is, the Com signal and the Seg signal are combined, and the peak-to-peak voltage Vpp is set to 50V. Also,
The pulse width was appropriately adjusted within a range where liquid crystal switching can be normally performed. In addition, the pretilt angle is determined by the so-called crystal rotation method (Jpn. J. Appl. Phy.
s. Vo. 119 (1980) NO. short No
The method described in tes2013). The liquid crystal for measuring the pretilt angle was a standard liquid crystal in which 20% by weight of a compound represented by the following structural formula was mixed with ferroelectric liquid crystal CS-1014 manufactured by Chisso Corporation.

[0027]

[Chemical 1] The mixed liquid crystal composition had a Sm of 10 to 50 ° C.
Phase A is shown. Then, the measurement method is such that while rotating the glass substrate in a plane perpendicular to the glass substrate and including the uniaxial orientation treatment axis,
A helium-neon laser beam with a deflection surface that makes an angle of ° is emitted from a direction perpendicular to the rotation axis, and on the opposite side, the transmitted light intensity is obtained with a photodiode through a deflection plate that has a transmission axis parallel to the incident deflection surface. It was measured. At this time, the angle formed by the center angle of the hyperbolic group of transmitted light intensity formed by interference and the line perpendicular to the glass substrate was defined as φx, and the pretilt angle α was calculated by substituting it in the following formula.

[0028]

[Equation 1] n ₀ : ordinary light refractive index n _e : extraordinary light refractive index Table 1 shows the experimental results.

[0029]

[Table 1] From the experimental results shown in Table 1, the following matters can be understood.

That is, regarding the orientation state in which the driving voltage is not applied (before driving), the heat treatment temperature of 100 ° C. or less and the untreated state show a good uniform state. When the temperature was 120 ° C. or higher, C2 orientation was mixed. Further, when driven at a temperature of 15 ° C., C2 orientation was mixed even in the heat treatment temperature of 100 ° C. Then, with respect to the liquid crystal in which the C2 orientation was mixed, it was confirmed that zigzag defects were generated, and that the contrast was remarkably lowered. The heat treatment temperature is 8
When the temperature is 0 ° C or less, the driving temperature is 30 ° C or 45 ° C.
Even if the temperature was raised to 0 ° C, C2 orientation was not observed.

When a heat history of 100 ° C. or higher is applied in this way, C2 orientation is mixed and zigzag defects occur, but it is also confirmed that the zigzag defects become more remarkable as the temperature of the heat history increases. did. Although not shown in Table 1, it was also confirmed that when the pretilt angle α was set to less than 10 °, the C2 orientation was mixed with the uniform orientation of the C1 orientation, and zigzag defects were generated. Such defects become remarkable when the driving voltage is increased or the temperature of the liquid crystal element is decreased.

Further, the inventor of the present invention conducted the same experiment by increasing the heat treatment time from 6 hours to 20 hours. The experimental results are shown in Table 2.

[0033]

[Table 2] By comparing the sample heat-treated for 20 hours in this experiment with the sample heat-treated for 6 hours in the above experiment, the following was found. That is, in the sample treated at a temperature of 100 ° C. or higher, when the heat treatment time is extended, C2
Mixing of states becomes significant, and zigzag defects also increase. On the other hand, when the treatment is performed at a temperature of 80 ° C. or lower, good uniform orientation can be obtained even if the heat treatment time is extended. From this, the thermal history is 10 regardless of the heat treatment time.
It was confirmed that if the temperature is lower than 0 ° C, good uniform orientation can be obtained.

The present inventor further extended the heat treatment time and conducted the experiment for 30 hours, but at a temperature of 80 ° C. or lower, a good uniform state was obtained.

Next, a second embodiment of the present invention will be described.

In the present embodiment, the time for which a heat history of 100 ° C. or more is applied after the uniaxial alignment treatment until the liquid crystal is injected is t1, and the time of applying a heat history of 80 ° C. or more after the liquid crystal is injected is t1. When t2 is set, the relation of 2t1> t2 ≧ t1 is established.

As a result, the liquid crystal was in a uniform uniform state. Hereinafter, an experiment conducted by the present inventor to confirm the effect will be described.

Also in this embodiment, a cell was prepared in the same manner as the above-mentioned embodiment. That is, the glass substrates 11a and 11b used in this experiment had a size of 7.5 cm × 7.5 cm, and the transparent electrodes 12 were formed on the surfaces of the substrates 11a and 11b.
a and 12b were formed. In addition, these transparent electrodes 12
A thin film of tantalum oxide (insulating film 13
a, 13b) was formed by a sputtering method, and a 1% NMP solution of fluorine-based polyimide was applied thereon by a spinner and baked at 270 ° C. for 1 hour to form alignment control layers 14a, 14b. Next, the substrates 11a and 11b were rubbed to set the pretilt angle α to 10 ° or more. Further, the rubbing directions are twisted in the clockwise direction when viewed from above the cell from the same direction and parallel to each other, so that the crossing angle θ _c between them is 10 ° and the cell thickness of 1.5 μm is maintained. , 11b were stuck together to form a cell. In the step of washing and drying the cell after rubbing (first step), IPA (isopropyl alcohol) was used as the washing liquid so that the drying could be performed at a low temperature (80 ° C.). In addition, in the step of bonding the upper and lower substrates 11a and 11b (second step), a UV curing seal is used as a seal member so that it can be cured by UV light and heat history is not added.

Five cells were prepared by the above method, and four of them were heat-treated at 100 ° C. for 6 hours. The remaining one cell was not heat-treated. Further, in these cells, as in the above-mentioned example, a cone angle 1 containing phenylpyrimidine as a main component was used.
Ferroelectric liquid crystal of 4 ° (at room temperature) was injected. In addition,
The temperature during this injection was 88 ° C., and the injection time was 1 hour. Then, after heat treatment was performed at 100 ° C. for 6 hours as described above, each of the four samples injected with the liquid crystal was treated with 100
Heat treatment was performed at 3 ° C. for 3 hours, 6 hours, 10 hours, and 20 hours. In addition, the heat treatment was omitted after the injection for the sample that was not heat treated before the liquid crystal injection. Then, these samples were gradually cooled to the chiral smectic C phase. Further, as in the above-described embodiment, 1. Alignment state before driving 2. Orientation state when driven at a driving voltage of 25 V at 2.15 ° C. Each orientation state of 3.30 ° C. 〃 4.45 ° C. 〃 was investigated.

The drive voltage having the waveform shown in FIG. 2 (b) was used, and the pretilt angle was measured by the crystal rotation method as in the above embodiment.

The experimental results are shown in Table 3.

[0042]

[Table 3] In this experiment, before driving the liquid crystal element, the C1 twist state was found to be mixed in those that were not heat-treated (untreated) and those that were heat-treated only for a short time of 3 hours. On the other hand, in the case of performing the heat treatment for 6 to 20 hours, a good uniform state was observed at least before driving. on the other hand,
When these samples were driven at each temperature, the one subjected to the heat treatment for 20 hours showed a mixture of C2 states at a driving temperature of 15 ° C. and many zigzag defects were generated. Also,
Regarding the one that was heat-treated for 6 hours, a mixture of C1 twist states was observed at a temperature of 45 ° C., and it was confirmed that the contrast was significantly lowered.

From the above experimental results, the time for applying a thermal history of 100 ° C. or more after the uniaxial alignment treatment until the liquid crystal is injected is set to t1 (t1 = 0, 6 hours in this embodiment), and the liquid crystal is injected. After that, the time for applying a thermal history of 80 ° C. or higher is t2 (t2 = 0, 3, 6, 1 in this embodiment).
0,20), defects are generated under the conditions of t2 <t1 (heat treatment for 3 hours) 2t1 <t2 (heat treatment for 20 hours), and t2 ≦ t1 (heat treatment for 6 hours). No defects occurred under the conditions of (1). That is, 2t1> t
It can be seen that under the condition of 2 ≧ t1, uniform uniform orientation can be obtained regardless of whether or not driving is performed.

It is considered that this is because the pretilt angle is affected by the thermal history, and the effects on the pretilt angle are opposite at t1 and t2.
That is, t1 affects the direction of decreasing the pretilt angle,
It is considered that t2 affects the direction of increasing the pretilt angle. Therefore, t1 and t2 must be managed in order to stably create the alignment state (t1 = 0 hours, t2 = 0 hours) controlled by the uniaxial alignment treatment.

Further, the present inventor conducted another experiment in order to confirm the effect of this embodiment. That is, the cells before the liquid crystal injection are subjected to heat treatment at temperatures of 50 ° C., 80 ° C., 100 ° C., and 120 ° C. for 3, 6, 10, 20, and 50 hours, respectively, and the cells before being subjected to the heat treatment are subjected to the pre-driving The orientation state was investigated. The results are shown in Table 4.

[0046]

[Table 4] From this experiment, it was confirmed that the samples subjected to the heat treatment at a temperature of 100 ° C. or higher showed a large change in the orientation state, but the heat treatment temperatures of 50 ° C. and 80 ° C. did not show a large change in the orientation state. From this experiment, it was found that the thermal history from the uniaxial alignment treatment to the liquid crystal injection largely affects the alignment state at a temperature of 100 ° C. or higher. The value of 100 ° C. is sufficiently smaller than the α dispersion point and β dispersion point of the polyimide alignment film.

Further, the present inventor heat-treats the cell before liquid crystal injection at 100 ° C. for 6 hours, and after the liquid crystal injection, the temperature is 50 ° C., 80 ° C., 100 ° C., and the time is 3, 6, 10,
After heat treatment for 20 to 50 hours, the alignment state before driving was examined together with the cells not subjected to heat treatment. The results are shown in Table 5.
Shown in.

[0048]

[Table 5] From this experiment, even if the thermal history of liquid crystal is 80 ° C
At the above temperatures, changes in the alignment state could be observed with time, but at 50 ° C no change in the alignment state was observed. From this experiment, it is understood that the temperature of 80 ° C. or higher has a great influence on the alignment state in the thermal history after the liquid crystal injection. Also,
This value of 80 ° C is the α dispersion point or β of the polyimide alignment film.
The value is sufficiently smaller than the dispersion point, and is smaller than the case of thermal history before liquid crystal injection. Considering these points, it is considered that the temperature affected by the thermal history is determined not by the α dispersion point or β dispersion point of the polyimide alignment film but by the relationship between the liquid crystal material and the alignment film.

[0049]

As described above, according to the first invention, the pretilt angle α of the manufactured liquid crystal element is maintained at 10 ° or more, and a stable large pretilt angle can be achieved. Then, it is possible to stably create a good uniform alignment state without alignment defects such as zigzag defects.

Also according to the second aspect of the present invention, it is possible to stably obtain a good uniform orientation state without a twist state or a zigzag defect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of a liquid crystal element.

FIG. 2 is a diagram for explaining drive waveforms.

FIG. 3 is a diagram for explaining C1 orientation and C2 orientation.

FIG. 4 is a diagram for explaining twist orientation and uniform orientation.

[Explanation of symbols]

 11a, 11b Substrate 12a, 12b Electrode (transparent electrode) 13a, 13b Insulating film 14a, 14b Alignment film (alignment control layer) 15 Ferroelectric liquid crystal

Claims (8)

[Claims] 1. A first step of cleaning and drying a substrate on which an electrode and an alignment film subjected to a uniaxial alignment treatment are formed, and a step of bonding the washed and dried pair of substrates with a seal member and then the seal. Manufacture of a ferroelectric liquid crystal device including a second step of curing a member, and a third step of injecting a ferroelectric liquid crystal after deaeration between a pair of substrates sealed by the sealing member In the method, the first step, the second step, and the third step are performed 100 times.
A method for manufacturing a ferroelectric liquid crystal element, which is performed at a temperature of ℃ or less. 2. The ferroelectric property according to claim 1, wherein the uniaxial alignment treatment is performed so that an angle formed between the interface of the alignment film and the ferroelectric liquid crystal is 10 ° or more. Liquid crystal device manufacturing method. 3. The method for manufacturing a ferroelectric liquid crystal device according to claim 1, wherein the uniaxial alignment treatment is performed by rubbing a polymer thin film. 4. The uniaxial orientation treatment at the upper and lower interfaces of the substrate intersects each other, and the intersection angle θ _c is 20 °> θ _c >.
It is 0 degree, The manufacturing method of the ferroelectric liquid crystal element of any one of Claim 1 thru | or 3 characterized by the above-mentioned. 5. A first step of cleaning and drying a substrate on which an electrode and an alignment film subjected to uniaxial alignment treatment are formed, and a third step of injecting a ferroelectric liquid crystal between a pair of bonded substrates.
In the method for manufacturing a ferroelectric liquid crystal device, the method includes the step of, and a temperature of 100 ° C. or higher until the ferroelectric liquid crystal is injected in the third step after the uniaxial alignment treatment in the first step. Ferroelectric liquid crystal, characterized in that the relationship of 2t1> t2 ≧ t1 is established when the heating time is t1 and the heating time after injection of the liquid crystal is 80 ° C. or more is t2. Device manufacturing method. 6. The ferroelectric liquid crystal according to claim 5, wherein the thermal history applied after the uniaxial alignment treatment and before the liquid crystal is injected is approximately equal to the thermal history applied after the liquid crystal is injected. Device manufacturing method. 7. The method of manufacturing a ferroelectric liquid crystal device according to claim 5, wherein the uniaxial alignment treatment is performed by rubbing a polymer thin film. 8. The uniaxial orientation treatment at the upper and lower interfaces of the substrate intersects each other, and the intersection angle θ _c is 20 °> θ _c >.
It is 0 degree, The manufacturing method of the ferroelectric liquid crystal element as described in any one of Claims 5 thru | or 7 characterized by the above-mentioned.