JPH11326917A - Liquid crystal display element and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain uniform cell thickness and to make a display good by specifying the relation of thickness and Young's modulus of a substrate, the arrangement pitch of a wall-like spacer, a pressure in the case of press-sticking the substrate and the changes in the cell thickness allowed for a liquid crystal display element. SOLUTION: Polymer walls 40 (wall-like spacers) having the width W, height H and length B are provided in a stripe shape between a pair of substrates 48a and 48b. In the case that the thickness of the substrate 48b is made to A, the Young's modulus of the substrate 48b is mode to E and the pitch of the polymer walls (the distance up to the center position of one polymer wall 40 in the X-direction) is made to L, this liquid crystal cell satisfies the condition of PL<4> /EA<3> <=Vπ<5> /48, wherein P is a pressure applied in the case of sticking the substrates 48a,/ 48b by press-sticking in a process for manufacturing the liquid crystal cell and V is the deviation amt. in the cell thickness allowed in the liquid crystal cell. The polymer walls 40 are formed over the whole longitudinal direction of the substrate 48b and its length is equal to the length B of the substrate 48b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly to a liquid crystal display capable of displaying a large screen and high definition.

[0002]

2. Description of the Related Art Ferroelectric liquid crystals have excellent features such as memory characteristics, high-speed response, and a wide viewing angle, and are capable of high-resolution, large-capacity display by a simple matrix method [NA Clark and ST Lagerwall: Appl. Phys. Lett
36 (1980) 899.]. FIG. 11 is a schematic sectional view showing an example of a conventional structure of a ferroelectric liquid crystal display device.

[0003] A conventional ferroelectric liquid crystal display device has two glass substrates 12a and 12b. On the surface of one glass substrate 12a, indium tin oxide (generally ITO)
) Are arranged in parallel with each other, and a transparent insulating film 14a made of SiO ₂ or the like is formed thereon.

A transparent scanning electrode 13 made of ITO or the like is provided on the surface of the other glass substrate 12b facing the signal electrode.
b are arranged in parallel with each other in a direction orthogonal to the signal electrodes 13a, and the scanning electrodes 13b are also made of SiO ₂
And the like.

[0005] On each of the transparent insulating films 14a and 14b, an alignment film 15a and a uniaxially-aligned film such as a rubbing process are applied.
15b is formed. As the alignment films 15a and 15b,
An organic polymer film such as a polyimide film, a nylon film, and a polyvinyl alcohol film, and a SiO oblique deposition film are used. When organic polymer films are used as the alignment films 15a and 15b, an alignment process is usually performed so that liquid crystal molecules are aligned substantially parallel to the electrode substrate.

Hereinafter, the signal electrode 13a, the transparent insulating film 1
The glass substrate 12 a on which the alignment film 4 a and the alignment film 15 a are sequentially stacked is referred to as an electrode substrate 10. Similarly, scan electrode 1
The glass substrate 12b on which the transparent insulating film 3b, the transparent insulating film 14b, and the alignment film 15b are sequentially laminated is referred to as an electrode substrate 11.

The electrode substrates 10 and 11 are bonded together with a sealant 16 except for a part of the injection port, and the alignment films 15a and 1
The ferroelectric liquid crystal 17 is introduced from the injection port into the gap formed between 5b. Thereafter, the inlet is sealed with a sealant 30.

[0008] The electrode substrate 1 bonded in this manner.
0.11 is sandwiched between two polarizing plates 18a and 18b arranged so that the polarization axes are orthogonal to each other. When the display area is large, spherical spacers 19 are scattered so that the two electrode substrates 10 and 11 face each other in parallel with a constant cell thickness.

As shown in FIG. 12, the ferroelectric liquid crystal molecule 20 has a spontaneous polarization 21 in a direction orthogonal to the long axis direction of the molecule.
have. Therefore, the molecules 20 of the ferroelectric liquid crystal receive a force proportional to the vector product of the electric field created by the voltage applied between the signal electrode 13a and the scanning electrode 13b and the spontaneous polarization 21 and the conical trajectory 22 Exercise on the surface of.

Therefore, as seen from the observer, the molecules 20 of the ferroelectric liquid crystal switch between the positions A and B on both axes of the conical trajectory 22 as shown in FIG. At this time, for example, one of the polarization axes of the polarizing plates 18a and 18b is oriented in the direction 38 of the molecular long axis when the molecule 20 is at the position A.
a, and the other polarization axis is aligned with the direction 38b, a dark field is obtained when the molecule 20 switches to position A. Also, when the molecule 20 switches to position B, a bright field caused by birefringence is obtained.

The orientation states of the molecules 20 of the ferroelectric liquid crystal at the positions A and B are equivalent in elastic energy. Thereby, even after the electric field generated by the signal electrode 13a and the scanning electrode 13b is removed, the alignment state, that is, the optical state of the molecule 20 is maintained. This is the so-called memory effect of the ferroelectric liquid crystal. This memory effect is a characteristic not found in conventional nematic liquid crystals, and in addition to the high-speed response due to spontaneous polarization, the display device using ferroelectric liquid crystal can perform high-resolution large-capacity display with a simple matrix method. I have.

However, when a large-sized liquid crystal display device is realized by using a ferroelectric liquid crystal or the like, there are the following problems. That is, in the large-sized liquid crystal display device, the substrate is easily deformed due to bending due to the weight of the substrate itself, impact due to external force, and the like. In particular, in the case of ferroelectric liquid crystals, once the alignment of the liquid crystal is disturbed by external pressure or the like, it is difficult to restore the alignment even if the external pressure is removed. However, this results in a remarkably different light transmission amount between these regions.

For this reason, a method of preventing deformation of a substrate by inserting a spherical spacer inside a liquid crystal cell or imparting adhesiveness to the spacer has been widely used.
In addition, a method of forming a wall structure made of a polymer resin (hereinafter, referred to as a polymer wall) inside a liquid crystal cell is also known. In the configuration having such a polymer wall, the deformation of the substrate of the liquid crystal cell and the flow of the liquid crystal are suppressed, and the display failure due to these is improved.

[0014]

However, the liquid crystal display device having a polymer wall as described above has a problem to be further solved as described below.

That is, in a liquid crystal display device having a polymer wall, if the adhesion between the substrates via the polymer wall is sufficiently strengthened, there is an effect of preventing the substrate from being compressed and tensilely deformed. However, if the adhesion between the substrates is insufficient, there is a problem that the cell thickness changes due to the deformation of the substrate due to the compression / pulling of the substrate, resulting in display failure. The deformation of the substrate is small near the polymer wall, but large in the region between the adjacent polymer walls.

One of the causes of such substrate deformation is that a pair of substrates are pressed against each other with a uniform pressure in the cell bonding step. In this case, if both substrates are adhered while applying an excessive pressure, the substrate is deformed in a region between adjacent polymer walls.

As a result, since the cell thickness becomes non-uniform, the voltage applied to the liquid crystal becomes non-uniform, which causes a malfunction of the liquid crystal. Further, if the cell thickness is non-uniform, the amount of transmitted light is also non-uniform, causing a decrease in luminance and poor color tone, which causes a problem that gradation display becomes difficult.

Further, the liquid crystal display device has various factors,
Where the liquid crystal is not filled, that is, bubbles and cavities are generated. Bubbles and cavities appear as display defects of the liquid crystal display device as shown in FIG. Conventionally, T
In N liquid crystals, it is known that outgassing from the substrate surface of the liquid crystal cell or volume shrinkage of the liquid crystal during cooling causes bubbles.

Even in a liquid crystal cell having a polymer wall, various types of bubbles or cavities are generated due to factors other than the above, such as surface irregularities of a substrate. Bubbles or cavities appearing in a liquid crystal display device having a polymer wall include a cavity 25 of a type that is generated in parallel along the longitudinal direction of a polymer wall (not shown) and a polymer wall 110 as shown in FIG. Vertical type cavity 2
There are six.

Some small-sized bubbles or cavities completely disappear due to external force or reheating of the liquid crystal cell. However, even if the size at the time of generation is small, it becomes mechanically unstable. There are also different types of bubbles or cavities.

A bubble or cavity of a mechanically unstable type increases in size when a driving voltage is applied to the place where the bubble is generated or when the substrate is deformed near the place where the bubble is generated, and the display characteristics of the liquid crystal display device are increased. Will be impaired.

The present invention has been made in view of the above-described problems, and provides a liquid crystal display element capable of maintaining a uniform cell thickness and capable of providing a good display, and a method of manufacturing such a liquid crystal display element. Make it an issue.

[0023]

According to a first aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising: a pair of substrates each having at least an electrode and an alignment control layer having a striped wall shape. The method for manufacturing a liquid crystal display element bonded with a space between the spacers includes a step of forming a wall-shaped spacer on one of the pair of substrates and a step of bonding the pair of substrates by pressure bonding. A is the thickness, E is the Young's modulus of the substrate, L is the pitch at which the wall-like spacers are arranged, P is the pressure at which the substrate is pressed in the above process, and the amount of change in cell thickness allowed for the liquid crystal display element. the If is V, wherein the ^{PL 4 / EA 3 ≦ Vπ 5} /48 is established.

According to the above-described manufacturing method, even if a pressure P is applied in the step of bonding a pair of substrates by pressure bonding, the amount of change in cell thickness due to the pressure P falls within the allowable range (V). Thereby, the uniformity of the cell thickness can be improved and a liquid crystal display element free from display defects can be provided.

According to a second aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, wherein a pair of substrates each having at least an electrode and an alignment control layer are bonded to each other at intervals by a striped wall spacer. A step of forming a wall-shaped spacer having a pitch L and a height H on one of the pair of substrates, and a step of pressing another substrate with a pressure P against the substrate on which the wall-shaped spacer is formed. , E the Young's modulus of the other substrate, when the thickness is a, wherein the ^{PL 4 / EA 3 H ≦ π} 5/48 is established.

According to the above-described manufacturing method, even if a pressure P is applied in the step of pressing another substrate against the substrate after forming the wall-shaped spacer on one of the pair of substrates, the pressure P The amount of deflection of the substrate can be kept within a range where the substrate on which the wall-shaped spacer is formed and the other substrate do not contact each other. In addition, other substrates are
It includes the other of the pair of substrates, a transfer substrate used to transfer an adhesive to the upper surface of the wall-shaped spacer for bonding the pair of substrates, and the like. Thereby, a liquid crystal display element free from display defects due to substrate deformation can be provided.

The liquid crystal display element according to claim 3, wherein a pair of substrates each having at least an electrode and an alignment control layer are bonded to each other at intervals by a striped wall spacer. Where P is the withstand pressure limit pressure and V is the displacement of the cell thickness at which a change in the liquid crystal alignment occurs, the pitch L, height H, width W, and Young's modulus E of the above-mentioned wall spacer are PLH ² / EW ² ≦ 2V. It is characterized by satisfying.

According to the above configuration, when an external force such as an impact is applied, if the magnitude of the external force is smaller than the withstand pressure limit pressure P, the displacement of the cell thickness caused by the external force becomes
It falls within a range that does not affect the change in the liquid crystal alignment. Thereby, a liquid crystal display element having excellent shock resistance can be provided.

The liquid crystal display device according to the fourth aspect is the third aspect.
In the configuration described above, a resin layer is provided on at least one of the substrates, the thickness of the resin layer is h _P , the height of the wall-shaped spacer main portion is h _W , the Young's modulus of the resin layer is E _P , and the wall-shaped spacer is Assuming that the Young's modulus of the main part is E _W , H = h _P + h _W , E = (E _P h _P + E _W h _W ) / (h _P
+ H _W ).

According to the above structure, for example, even in a structure having a resin layer such as a color filter, the thickness of the resin layer and the height of the wall spacer are adjusted according to the respective Young's moduli. The amount of displacement of the cell thickness when an external force smaller than the withstand pressure limit pressure is applied can be kept within a range that does not affect the change in the liquid crystal alignment. As a result, a liquid crystal display device having excellent shock resistance can be provided.

According to a fifth aspect of the present invention, there is provided a liquid crystal display device comprising a pair of substrates each having at least an electrode and an alignment control layer, each of which is bonded to each other at intervals by a striped wall spacer. A,
If the Young's modulus of the substrate is E, the pitch of the wall spacer is L, the adhesive force between the pair of substrates is G, the length of the unevenness on the substrate surface is λ, and the height of the unevenness is Δ, GλL ⁶ / Δ ² A ⁶ E ≧ 0.05.

According to the above configuration, even if irregularities are generated on the substrate surface due to various factors in the manufacturing process, the influence of the peeling stress generated between the substrates can be reduced. As a result, a liquid crystal display element without bubbles and cavities can be provided.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, wherein a pair of substrates each having at least an electrode and an alignment control layer are bonded to each other at intervals by a striped wall spacer. A step of forming a wall-shaped spacer on one of the pair of substrates and a step of bonding the pair of substrates by pressure bonding, wherein the thickness of the substrate is A, the Young's modulus of the substrate is E, When the pitch at which the spacers are arranged is L and the pressure at which the substrate is pressed in the above step is P, PL ⁴ / EA ³ ≦ 0.00065 [mm] holds.

If P, L, E, and A satisfy the above conditions, the amount of change in cell thickness in the step of bonding a pair of substrates by pressure bonding is set to a range (0) that does not affect the change in liquid crystal alignment. ... 1 μm or less. Thereby, the uniformity of the cell thickness can be improved and a liquid crystal display element free from display defects can be provided.

8. The liquid crystal display device according to claim 7, wherein a pair of substrates each having at least an electrode and an alignment control layer are bonded to each other at intervals by a striped wall spacer. The pitch L, the height H, the width W, and the Young's modulus E of the wall-shaped spacer satisfy PLH ² / EW ² ≦ 0.2 [μm], where P is the withstand pressure limit pressure.

If P, L, H, E, and W satisfy the above conditions, when an external force such as an impact is applied, if the magnitude of the external force is smaller than the pressure limit pressure P, the external force The amount of displacement of the cell thickness caused by the change is within a range (within 0.1 μm) that does not affect the change of the liquid crystal alignment. Thereby, a liquid crystal display element having excellent shock resistance can be provided.

The liquid crystal display device according to the present invention is a liquid crystal display device wherein a pair of substrates each having at least an electrode and an alignment control layer are bonded to each other at a distance by a striped wall spacer. A,
When the pitch of the wall-shaped spacer is L, L ⁶ / A ⁶ ≧ 0.00015 is satisfied.

As long as L and A satisfy the above conditions, even if irregularities occur on the substrate surface due to various factors in the manufacturing process, the influence of the peeling stress generated between the substrates is reduced. Can be. As a result, a liquid crystal display element without bubbles and cavities can be provided.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] An embodiment according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the liquid crystal cell (liquid crystal display element) according to this embodiment has a pair of substrates 48a and 48b.
In this configuration, a polymer wall 40 (wall-like spacer) having a width W, a height H, and a length B is provided in a stripe shape. Each of the substrates 48a and 48b is provided with a transparent electrode made of, for example, ITO, an insulating film, an alignment film, and the like (neither is shown) as necessary.

In this liquid crystal cell, the thickness of the substrate 48b is A,
The Young's modulus of the substrate 48b is E, and the pitch of the polymer walls 80 (the distance from the center position of one polymer wall 40 to the center position of the adjacent polymer wall 40 in the X direction in the drawing) is L. , The condition shown in Equation 1 below holds. Note that P indicates a pressure applied when the substrates 48a and 48b are bonded to each other by pressure bonding in a manufacturing process of the liquid crystal cell, and V indicates a displacement of a cell thickness allowed in the liquid crystal cell. The polymer wall 40 is formed over the entire length of the substrate 48b in the length direction.
Its length is equal to the length B of the substrate 48b.

[0042]

(Equation 1)

The process of deriving the above conditions will be described below.

In the manufacturing process of the liquid crystal cell, the substrate 4
When bonding the substrates 8a and 48b by crimping,
Assuming that the pressure applied to b is P, the amount of deformation の of the substrate 48b under this pressure P is from the polymer wall 40 in a direction orthogonal to the longitudinal direction of the polymer wall 40 (X direction in the figure). Is given by the following equation 1 as a function of the distance x.

[0045]

(Equation 2)

Here, B is the length of the substrate 48b (Y in the figure)
E is the Young's modulus of the substrate 48b, I
Is the moment of inertia of the substrate 48b. Usually, the Young's modulus of a glass substrate is about 6500 to 7500 kg / mm ² , and that of a resin substrate is about 10 to 500 kg / mm ² . The moment of inertia I of the substrate 48b is represented by the following equation.

[0047]

(Equation 3)

Here, when the above equation 2 is solved under the boundary condition that the substrate deformation amount ξ (x) = 0 is satisfied at x = 0 and x = L, the following solution is obtained.

[0049]

(Equation 4)

From this equation ⁴ , it can be seen that the maximum deformation of the substrate 48b is given by 48PL ⁴ / π ⁵ A ³ E. Considering the uniformity of the display characteristics of the liquid crystal cell, the substrate 4
It is desirable that the deformation amount of 8b is equal to or less than a predetermined value. That is, assuming that this predetermined value is V, 48PL ⁴ / π ⁵ A
From ³ E ≦ V, the number 1 of the is derived.

FIG. 2 shows that in the above-mentioned liquid crystal cell, the pressure P was set at 1 kgf / cm ² and the pitch L of the polymer wall 40 was changed.
Is a graph showing the results obtained by measuring the maximum value of the amount of deformation ξ (x) of the substrate 48b with respect to the pitch L while changing the value of L in various ways. FIG. 2 shows that the maximum value of the amount of deformation ξ (x) of the substrate 48 b increases in proportion to the fourth power of the pitch L of the polymer walls 40. This is consistent with the L dependence of the amplitude in Equation 4.

In the case of the liquid crystal cell according to the present embodiment, in consideration of the uniformity of the display characteristics of the liquid crystal display device, it is required that the amount of change in the cell thickness is 0.1 μm or less, that is, V = 0.1 μm. Therefore, based on Equation 4, it is preferable that the pitch L of the polymer walls 40 and the thickness A of the substrate 48b satisfy the following relationship.

[0053]

(Equation 5)

Further, the substrate 48b is a glass substrate,
The Young's modulus E of this glass substrate is 7500 kg / mm ² ,
Assuming that the pressure P at the time of producing the cell is 0.01 kgf / mm ² , based on the above Equation 5, in the liquid crystal cell according to the present embodiment, the pitch L of the polymer walls 40 and the thickness A of the substrate 48 b It is further preferable that the relationship shown in the following Expression 6 is established between

[0055]

(Equation 6)

Here, a more specific example of the structure of the above-described liquid crystal cell and a method of manufacturing the same will be described with reference to FIG. First, a 200 nm-thick indium tin oxide (ITO) film is formed on the entire surface of a glass substrate 50a having a thickness of A = 0.7 mm by sputtering evaporation or EB evaporation. Next, a photoresist is spin-coated. Next, after the above photoresist was formed into a stripe pattern by photolithography using a photomask for forming an ITO electrode and an ultraviolet exposure apparatus,
Is immersed in a 47% by weight aqueous solution of hydrogen bromide for 10 minutes to etch the signal line 51a.

As the photoresist, for example, TSMR-8800 manufactured by Tokyo Ohka Kogyo Co., Ltd. can be used. In the above etching step, the width of the signal line 51a is 385 μm, the length of the pixel portion is 192 mm, and the width between the adjacent signal lines 51a is 51 mm.
μm.

Next, the glass substrate 50a on which the signal lines 51a are formed is washed with pure water and dried, and then a black matrix 56 is formed of resin or Si. A negative photosensitive acrylic resin (V-259PA: manufactured by Nippon Steel Chemical Co., Ltd.) is spin-coated thereon, and the height is 1.5 μm, the width of the lower side of the trapezoid is 15 μm, and the upper side is 1 by photolithography with a proximity gap of 50 μm.
A 0 μm polymer wall 54 is formed. Here, the pitch L of the polymer walls 54 was 2 mm.

On the polymer wall 54, silicon oxide SiO
_An insulating film 52a made of ₂ or silicon nitride SiN;
An alignment film 53a made of polyimide is sequentially formed, and a uniaxial alignment process by rubbing is performed on the alignment film 53a.

Through the above steps, the signal line substrate 58a is manufactured.

Similarly, the scanning lines 51 are placed on the glass substrate 50b.
b, an insulating film 52b, and an alignment film 53b are sequentially formed to form a scanning line substrate 58b and a signal line substrate 5b.
The substrate 8a and the scanning line substrate 58b are opposed to each other, the temperature is kept at 200 ° C., and the two substrates are adhered for 1 hour at a pressure of 1 kg / cm ² while evacuating. Thereafter, a liquid crystal cell is completed by injecting liquid crystal. The Young's modulus of the glass substrates 50a and 50b used here was 7500 kg /
mm ² .

As a result of examining the non-uniformity of the cell thickness of the liquid crystal cell thus produced, the polymer walls 54.5
It was found that the cell thickness in the central portion between the four was smaller than the cell thickness in the vicinity of the polymer wall 54 by about 0.01 μm. However, this value falls within a range in which preferable display characteristics can be realized.

On the other hand, the pitch L of the polymer walls 54 is 3.6 m
When a liquid crystal cell was prepared in the same manner as above except for the above conditions, the cell thickness at the center between the adjacent polymer walls 54 was 0.1 μm. This value is
This is a limit value within a range in which preferable display characteristics can be realized.

Note that the above values of L, A, and P are:
This satisfies the above-mentioned conditions of Expressions 5 and 6.

Embodiment 2 Another embodiment according to the present invention will be described with reference to FIGS. 4 and 5.
It is as follows.

The liquid crystal cell according to the present embodiment includes a signal line substrate 68a and a scanning line substrate 68b as shown in FIG.

The signal line substrate 68a is formed on the surface of the glass substrate 60a by forming signal lines 61a, 61 formed in stripes.
and black matrices 66 formed so as to fill the intervals between the signal lines 61a. On the upper layer of the black matrix 66, the polymer wall 6 has a width along the longitudinal direction of the black matrix 66 and a width smaller than that of the black matrix 66.
4 (wall-like spacers) are formed. This polymer wall 6
4 has a trapezoidal shape in a cross section perpendicular to the longitudinal direction. Further, an insulating film 62a and an alignment film 63a are sequentially laminated so as to cover the signal lines 61a, the black matrix 66, and the polymer wall 64.

Similarly, the scanning line substrate 68b is formed on the surface of the glass substrate 60b by a scanning line 61 formed in a stripe shape.
.., 61b, an insulating film 62b, and an alignment film 63b are sequentially laminated.

The signal line substrate 68a and the scanning line substrate 68b are arranged so that the signal lines 61a and the scanning lines 61b are orthogonal to each other.
The alignment film 63a on the upper surface of the substrate 4 and the alignment film 63b on the scanning line substrate 68b side are firmly adhered by the adhesive layer 65. The liquid crystal (not shown) includes alignment films 63a and 6a.
The space formed between 3b is filled.

Next, an example of a method for manufacturing the above-described liquid crystal cell will be described with reference to FIGS. Note that the material names, manufacturing conditions, and the like shown in the following description are merely examples, and the present invention is not limited thereto.

First, a film having a thickness of 2
A film of indium tin oxide (ITO) having a thickness of 00 nm is formed by sputtering evaporation or EB evaporation. Next, a photoresist is spin-coated. Next, ITO
The photoresist is formed into a stripe pattern by photolithography using a photomask for electrode formation and an ultraviolet exposure apparatus, and then immersed in a 47% by weight aqueous solution of hydrogen bromide at 35 ° C. for 10 minutes to etch the signal line 61a. Do.

The photoresist may be, for example, TSMR-8800 manufactured by Tokyo Ohka Kogyo Co., Ltd. In the above etching step, the width of the signal line 61a is 385 μm, the length of the pixel portion is 192 mm, and the width between the adjacent signal lines 61a and 61a is 15 μm.
μm.

Next, the glass substrate 60a on which the signal lines 61a are formed is washed with pure water and dried, and then a black matrix 66 is formed of resin or Si.

Subsequently, a negative photosensitive acrylic resin (V
-259PA: manufactured by Nippon Steel Chemical Co., Ltd.), and a polymer wall 64 having a height of 1.5 μm, a width of a trapezoidal lower side of 15 μm, and an upper side of 10 μm is formed by photolithography with a proximity gap of 50 μm. In addition, the pitch L of the polymer wall 64 was set to 6 mm.

An insulating film 62a made of silicon oxide SiO ₂ or silicon nitride SiN and an alignment film 63a made of polyimide are sequentially formed thereon, and the alignment film 63a is subjected to a uniaxial alignment process by rubbing.

Through the above steps, the signal line substrate 68a is manufactured as shown in FIG.

Next, an adhesive layer 65 is formed on the surface of the alignment film 63a on the upper surface of the polymer wall 64 by the processes shown in FIGS. 5B to 5D. First, as shown in FIG. 5B, an adhesive resin film diluted with a solvent is formed on a transfer substrate 67 used to transfer the adhesive to the alignment film 63a on the upper surface of the polymer wall 64. Here, a two-part epoxy adhesive (base agent 1) diluted with 25 cc of n-butyl cellosolve was used.
g, curing agent 1 g: manufactured by Konishi Co., Ltd., trade name "Bond E")
Is formed by spin coating to a thickness of 200 nm.

Alternatively, a similar adhesive layer 65 may be formed by forming a polyimide film on the transfer substrate 67 and spraying the diluted two-liquid epoxy adhesive described above by a spray method.

Thereafter, the solvent contained in the adhesive layer 65 is dried at 80 ° C. for 180 seconds, and then, as shown in FIG. In a flat state, the pieces are once bonded by air-pressing at a pressure of 1 kgf / cm ² . At this time, the alignment film 63 a on the upper surface of the polymer wall 64 is brought into contact with the adhesive layer 65. Finally, the signal line substrate 68a and the transfer substrate 6
Peel 7 off. As a result, as shown in FIG. 5D, the adhesive layer 65 is moved from the transfer substrate 67 to the signal line substrate 68.
The pattern is transferred to the alignment film 63a on the upper surface of the polymer wall 64 of FIG.

The conditions required for the transfer substrate 67 are that there is no deterioration of the adhesive resin due to the solvent and that there is no obstacle to the transfer of the adhesive resin.

The signal line substrate 68a and the scanning line substrate 68b thus manufactured are opposed to each other, and a liquid crystal cell is manufactured by evacuating and injecting a liquid crystal into the bonded gap.

The magnitude of the pressure P applied in the step of pressing the signal line substrate 68a and the transfer substrate 67 (see FIG. 5 (c)) is determined by comparing the surface of the transfer substrate 67 with the signal line substrate 68.
The signal line substrate 68 is deformed such that the surface of the
It is necessary to control to a range that does not occur in a.

That is, it is necessary that the displacement amount 基板 of the substrate expressed by the above equation 4 is smaller than the height H of the polymer wall 64. That is, based on Equation 4, the condition shown in Equation 7 below is satisfied between the pressure P in the pressure bonding step, the pitch L and height H of the polymer wall 64, and the Young's modulus E and thickness A of the transfer substrate 67. It is necessary to hold. The values of P, L, H, E, and A shown in the present embodiment satisfy this condition.

[0084]

(Equation 7)

In this embodiment, the transfer substrate 67
When transferring the adhesive layer 65 from the to the signal line substrate 68a,
The amount of deformation of the transfer substrate 67 was 0.8 μm. Therefore,
Since the height H of the polymer wall 64 was 1 μm, the adhesive layer 65 was not transferred to a portion other than the upper surface of the polymer wall 64.

However, for comparison, when the pitch L of the polymer walls 64 was 6.5 mm and a liquid crystal cell was prototyped in the same manner as described above, the transfer substrate 67 was transferred in the transfer step shown in FIG. The substrate is deformed by 1.1 μm, and the alignment film 63a is formed.
In, the adhesive was transferred to portions other than the upper surface of the polymer wall 64. Note that the value of L does not satisfy Equation 7 above.

As described above, in this embodiment, the pressure P in the pressure bonding step, the pitch L / height H of the polymer wall 64, and the Young's modulus E / thickness A of the transfer substrate 67 are expressed by the following equation (7). The condition is satisfied.

Thus, the amount of deformation of the transfer substrate 67 caused by the application of the pressure P in the transfer step is determined so that the adhesive of the transfer substrate 67 is not transferred to the portion of the alignment film 63a other than the upper surface of the polymer wall 64. Can be in the range.

Third Embodiment Still another embodiment according to the present invention will be described below with reference to FIGS. 6 and 7.

In the liquid crystal cell according to the present embodiment, as shown in FIG. 6, a polymer wall 70 (wall-like spacer) having a width W, a height H and a length B is provided between a pair of substrates 78a and 78b. This is a configuration provided in a stripe shape. The pitch of the polymer walls 70 (the distance from the center position of one polymer wall 70 in the X direction in the figure to the center position of the adjacent polymer wall 70) is L.

Each of the substrates 78a and 78b has a transparent electrode made of, for example, ITO, an insulating film, a color filter,
And an alignment film and the like (neither is shown) are provided as needed.

In the liquid crystal cell according to this embodiment, even when a so-called external force such as an external impact is applied, the polymer wall 7
The pitch and the like of the polymer walls 70 are determined so that the amount of change in the cell thickness due to the deformation of 0 falls within a range in which the alignment of the liquid crystal is not disordered.

That is, in the present liquid crystal cell, assuming that the magnitude of the external force is P, the pitch L, the height H, and the width W of the polymer wall 70 are set so as to satisfy the following equation (8).
Here, E is the Young's modulus of the polymer wall 70,
V indicates that the alignment of the liquid crystal is disordered in the liquid crystal cell.
This is the critical value of the cell thickness displacement.

[0094]

(Equation 8)

Here, the process of deriving the condition of Equation 8 will be described. First, when the pressure P is applied to the present liquid crystal cell, how the substrate 78b is displaced with the deformation of the polymer wall 70 is analyzed.

As shown in FIG. 6, the polymer walls 70 are formed at a pitch L, and the length B (the length in the Y direction in the figure) is equal to the length of the substrate 78b. An equation for such substrate deformation is derived. Here, unlike in the first embodiment, it is assumed that the substrate 78b does not bend even when pressure is applied.

[0097]

(Equation 9)

Note that E represents the Young's modulus E of the polymer wall 70.
_W is given. The styrene or acrylic resin generally used as a material for the polymer wall 70 has a Young's modulus of 1
It takes a value of about 0 to 500 kg / mm ² . Equation 7 above
Is solved under the boundary condition that ξ (z) = 0 when z = 0, the following solution is obtained.

[0099]

(Equation 10)

Here, when the height H of the polymer wall 70 is substituted for the height z, the displacement ξ of the substrate 78b due to the pressure P is obtained. From this, Equation 8 can be derived.

When a resin layer (thickness: h _C ) such as a color filter is provided together with the polymer wall 70, the height of the polymer wall 70 (here, h _W Sum) and the thickness h _C of the resin layer (h _W +
h _C ) and the Young's modulus E, the Young's modulus (E _W ) of the polymer wall 70 and the Young's modulus of the color filter (E _C ).
As an average value _{between, (E W h W + E} C h C) / (h C +
h _W ).

Here, the pressure P was applied while changing the pitch L of the polymer walls 70 variously, and the shock resistance was evaluated. The shock resistance is indicated by the value of the pressure P when the orientation of the liquid crystal changes. FIG. 7 is a graph showing the result. The height H of the polymer wall 70 used here was 5 μm, and the width W was 5 μm.
Is 10 μm and the Young's modulus E is 37.5 kg / mm ² .

FIG. 7 shows that the pitch L of the polymer walls 70 and the pressure P when the orientation of the liquid crystal changes are in inverse proportion. When the result shown in FIG. 7 is applied to Expression 10, it can be seen that the displacement of the liquid crystal is changed by the displacement of the substrate of about 0.1 μm.

As a result, the orientation of the liquid crystal is determined by the external pressure P
It can be seen that the cell structure should satisfy the following condition by substituting 0.1 μm for V in Eq.

[0105]

[Equation 11]

Here, the structure and the manufacturing process of the liquid crystal cell according to the present embodiment will be described with reference to more specific examples. The liquid crystal cell according to this specific example is almost the same as the configuration example described with reference to FIG. 3 in Embodiment 1 except that the size of each part is different. Explanation will be given while doing.

First, a glass substrate 5 having a thickness A = 0.7 mm
A 200 nm-thick indium tin oxide (ITO) film is formed on the entire surface of Oa by sputtering evaporation or EB evaporation. Next, a photoresist is spin-coated. Next, after the above photoresist was formed into a stripe pattern by photolithography using a photomask for forming an ITO electrode and an ultraviolet exposure apparatus,
Is immersed in a 47% by weight aqueous solution of hydrogen bromide for 10 minutes to etch the signal line 51a.

As the photoresist, for example, TSMR-8800 manufactured by Tokyo Ohka Kogyo Co., Ltd. can be used. In the above etching step, the width of the signal line 51a is 385 μm, the length of the pixel portion is 192 mm, and the width between the adjacent signal lines 51a is 51 mm.
μm.

Next, the glass substrate 50a on which the signal lines 51a are formed is washed with pure water and dried, and then a black matrix 56 is formed of resin or Si. A negative photosensitive acrylic resin (V-259PA: manufactured by Nippon Steel Chemical Co., Ltd.) is spin-coated thereon, and the height H is 5 μm, the width of the lower side of the trapezoid is 15 μm, and the upper side is 1 by photolithography with a proximity gap of 50 μm.
A 0 μm polymer wall 54 is formed. The polymer wall 54
Since the cross section is trapezoidal, its width is not constant, but the width of the short side (that is, the upper side) may be W.

Here, the Young's modulus E of the polymer wall 54 is 3
It is 7.5 kg / mm ² . Further, the pitch L of the polymer walls 54 is set to be smaller than 0.1 mm.

Next, the silicon oxide S
iO ₂ or silicon nitride SiN and the like insulating film 52a
And an alignment film 53a made of polyimide are sequentially formed,
The alignment film 53a is subjected to a uniaxial alignment process by rubbing.

Through the above steps, the signal line substrate 58a is manufactured.

Similarly, the scanning lines 51 are provided on the glass substrate 50b.
b, an insulating film 52b, and an alignment film 53b are sequentially formed to form a scanning line substrate 58b and a signal line substrate 5b.
The substrate 8a and the scanning line substrate 58b are opposed to each other, the temperature is kept at 200 ° C., and the two substrates are adhered for 1 hour at a pressure of 1 kg / cm ² while evacuating. Thereafter, a liquid crystal cell is completed by injecting liquid crystal.

As a result of examining the shock resistance of the liquid crystal cell thus manufactured, even when a pressure of 30 kg / cm ² was applied, the amount of change in the cell thickness was within a range where the orientation of the liquid crystal did not change (here, 0.1 μm). Less).

When L = 0.1 mm, 3
When a pressure of 0 kg / cm ² was applied, a change in the cell thickness of 0.1 μm occurred, and a change in the orientation of the liquid crystal was observed. In addition, a cell manufactured similarly with L = 0.3 mm is 10
When a pressure of kg / cm ² is applied, a change in cell thickness accompanying a change in the orientation of the liquid crystal occurs, and the shock resistance is further deteriorated.

[Embodiment 4] Still another embodiment of the present invention will be described below with reference to FIGS. 4, 5, and 8 to 14.

The liquid crystal cell according to the present embodiment includes a pair of substrates 88a and 88b as shown in FIG. A polymer wall 80 (wall-shaped spacer) having a width W, a height H, and a length B is provided on the substrate 88a in a stripe shape.
The substrate 88a is formed by the adhesive layer 84 formed on the upper surface of the substrate 88a.
And the substrate 88b are bonded to each other. In addition,
Let the pitch of the polymer walls 80 be L.

Each of the substrates 88a and 88b has a transparent electrode made of, for example, ITO, an insulating film, a color filter,
And an alignment film and the like (neither is shown) are provided as needed.

In this liquid crystal cell, as shown in FIG. 8, when the substrates 88a and 88b are bonded to each other, a crack 81 is formed between the adhesive layer 84 and the substrate 88b due to surface unevenness of one of the substrates. Even if the substrate 88a and the substrate 88b
The following conditions are satisfied so as not to generate bubbles or cavities in a liquid crystal (not shown) introduced between the first and second liquid crystals.

[0120]

(Equation 12)

G is a peeling adhesive force acting between the adhesive layer 84 and the substrate 88b (hereinafter simply referred to as an adhesive force), and λ is a typical length of the surface unevenness of the substrate 88a (λ ≧ L
N, N: integer), Δ is the size of the surface irregularities of the substrate 88a,
E indicates the Young's modulus of the substrate 88b.

Hereinafter, the process of deriving Equation 12 will be described.

It is considered that the cavities generated in the liquid crystal are caused by surface irregularities of the substrate. That is, on one of the pair of substrates constituting the liquid crystal cell,
In the case where surface irregularities occur due to some factor, when the other substrate is bonded to this substrate, the latter substrate also undergoes substrate deformation reflecting the surface irregularities of the former substrate. As a result, a peeling stress F is generated at a bonding portion between the polymer wall formed on one substrate and the other substrate, and a crack is generated.

In the vicinity of a crack, the cell thickness becomes large, and in the case of a liquid crystal having a high viscosity, it becomes impossible to follow the change in the cell thickness. As a result, in order to minimize the surface of the liquid crystal near the polymer wall, a cavity, which is a portion not filled with the liquid crystal, is generated.

Here, how the peeling stress F leads to the generation of a cavity will be described in more detail.

The surface irregularities generated on the substrate of the liquid crystal cell mainly include 1) a size larger than the pitch of the polymer walls and uniformly occurring in the length B direction of the substrate, and 2) a pitch of the polymer walls. It is divided into two types: a smaller size and a case where it is scattered on the substrate. The former occurs when a film is formed using a wiring material or the like, and the latter occurs when there are small protrusions or dust on the substrate.

First, the former case will be described with reference to FIG. As shown in FIG. 8, a typical length λ is provided on the surface of the substrate 88a in which the polymer walls 80 are formed at the pitch L.
It is assumed that ≧ LN (N: integer) and that there are surface irregularities having a size of Δ. Here, it is particularly assumed that the surface irregularities are uniform in the longitudinal direction of the substrate.

The substrate 88a and the other substrate 88b are
When the bonding is performed via the polymer wall 80, the substrate 88b having the Young's modulus E is deformed by about Δ / N. Due to this deformation, a peeling stress F acting on the substrate 88b on the polymer wall in a direction of peeling the substrate 88b from the substrate 88a is generated. Peeling stress F
Is represented by the following Expression 13.

[0129]

(Equation 13)

The stress F is applied to the substrate 88 on the polymer wall 80.
It occurs uniformly along b. On the other hand, there is an adhesive layer 84 having an adhesive force G between the polymer wall 80 and the substrate 88b.
The stress F and the adhesive force G act as a force for generating the crack 81 and a force for suppressing the same, and when the length of the crack 81 generated between the substrate 88b and the polymer wall 80 is Γ, The following equation 14 holds.

[0131]

[Equation 14]

Equation 14 indicates that when the stress F decreases, the crack 8
1 indicates that the length Γ increases, and it can be seen that the crack 81 is unstable. That is, cracks longer than this length Γ become longer and shorter cracks gradually disappear.
Therefore, Γ in Expression 14 represents the critical length of the crack 81.

On the other hand, as shown in FIG. 9, a crack 91 having a size smaller than the pitch of the polymer wall 80 is formed.
In the case of, small protrusions 86 (or dust)
And the length D does not increase, and the crack 9
1 is stable.

In this case, the polymer wall 8 near the projection 86
The peeling stress f acts between 0 and the substrate 88b. The size D of the crack 91 in this case is given by
It is represented by

[0135]

(Equation 15)

This indicates that the crack 91 does not increase when the stress f decreases, and in this case, the crack 91 does not increase.
Is stable regardless of the size D.

The cracks of this type are caused by small projections and dust as described above. When the substrate deformation due to the cracks reaches the order of the size of the projections and dust,
No more size. For this reason, cracks 91 of the type shown in FIG. 9 are generally smaller than cracks 81 of the type shown in FIG.

As an example, stress f = 10 kg, Young's modulus E = 7500 kg / mm ² , adhesive force G of adhesive layer 84 =
Assuming 0.02 kg / mm, the size D of the crack 91 is:
It becomes 100 μm.

When such a crack 91 exists,
Although the cavities do not expand, the cavities cannot be eliminated even if realignment treatment is performed by applying an external force to the liquid crystal cell. Therefore, small projections and dust that cause cavities are not generated during cell fabrication.
It is an essential solution.

On the other hand, when there is an unstable and expanding type crack such as the crack 81 shown in FIG. 8, the cavity also expands in accordance with the expansion of the crack 81. As a result, when the crack 81 is longer than the critical length, the cavity can be temporarily eliminated by applying an external force to the liquid crystal cell or performing a realignment treatment such as heating, but as time passes, The cavity reappears. On the other hand, when the crack 81 is shorter than the critical length, if the cavity is eliminated by performing reorientation treatment such as heating, the cavity will not appear again.

In order to suppress the generation of cavities, the essential solution is to increase the typical length λ of the unevenness on the substrate surface and reduce the size Δ of the unevenness on the surface of the substrate. Of the substrate 88b or the thickness A of the substrate 88b.
Is considered as the next best solution.

FIG. 10 shows the relationship between the pitch L of the polymer walls 80 and the length of the generated cavity.
When a crack is formed in the bonded portion of the glass, the cell volume of the portion changes, and a cavity is formed. Therefore, the length of the cavity is substantially equal to the length of the crack. From FIG.
It can be seen that the length of the cavity is proportional to the sixth power of the pitch L of the polymer wall 80. The longer the pitch L between the polymer walls 80, the wider the area where no cavity is generated.

This result is consistent with the expression (14). From FIG. 10, it can be seen that in order to eliminate the cavity, it is necessary that the critical length 長 of the crack represented by Expression 14 is larger than the typical length λ of the surface irregularities of the substrate. This leads to Equation 12 described above.

Here, the Young's modulus of the glass substrate E = 750
0 kg / mm ² , the adhesive force G of an adhesive generally used as a material for the adhesive layer 84 is 0.02 kg / mm ² , the length λ of the substrate unevenness is 5 mm, and the size Δ is 0.2 μm
Then, the following condition is derived from Expression 12.

[0145]

(Equation 16)

Here, the structure and the manufacturing process of the liquid crystal cell according to the present embodiment will be described using more specific examples. Note that the liquid crystal cell according to this specific example is substantially the same as the configuration example described with reference to FIGS. 4 and 5 in Embodiment 2, except that the size and the like of each part are different. The description will be made with reference to FIGS. Further, the material names, manufacturing conditions, and the like shown in the following description are merely examples, and the present invention is not limited thereto.

First, a glass substrate 60a having a thickness of 1.1 mm was used.
Of indium tin oxide (IT) having a thickness of 600 nm
The film O) is formed by sputtering evaporation or EB evaporation. Next, a photoresist is spin-coated. Next, the photoresist is formed into a stripe pattern by photolithography using a photomask for forming an ITO electrode and an ultraviolet exposure apparatus.
The signal line 61a is etched by immersing in a 10% by weight aqueous solution of hydrogen bromide for 10 minutes.

As the photoresist, for example, TSMR-8800 manufactured by Tokyo Ohka Kogyo Co., Ltd. or the like can be used. In the above etching step, the width of the signal line 61a is 385 μm, the length of the pixel portion is 192 mm, and the width between the adjacent signal lines 61a and 61a is 15 μm.
μm.

Next, the glass substrate 60a on which the signal lines 61a are formed is washed with pure water and dried, and then a black matrix 66 is formed of resin or Si.

However, the signal line board 68a at this time is
Due to the unevenness of the film formation of ITO when forming the signal line 61a,
In the direction perpendicular to the polymer wall 64, the surface has a surface irregularity having a size Δ = 0.002 mm over a typical length λ = 5 mm.

Subsequently, a negative photosensitive acrylic resin (V
-259PA: Nippon Steel Chemical Co., Ltd.), spin-coated by photolithography with a proximity gap of 50 μm, height 1 μm, width of trapezoidal lower side 15
A polymer wall 64 of 10 μm on the upper side is formed. In addition,
The pitch L of the polymer walls 64 is set to 0.26 mm.

An insulating film 62a made of silicon oxide SiO ₂ or silicon nitride SiN and an alignment film 63a made of polyimide are sequentially formed thereon, and the alignment film 63a is subjected to a uniaxial alignment process by rubbing.

Through the above steps, the signal line substrate 68a is manufactured as shown in FIG.

Next, an adhesive layer 65 is formed on the surface of the alignment film 63a on the upper surface of the polymer wall 64 by the processes shown in FIGS. 5B to 5D. First, as shown in FIG. 5B, an adhesive resin film diluted with a solvent is formed on a transfer substrate 67 used to transfer the adhesive to the alignment film 63a on the upper surface of the polymer wall 64. Here, a two-part epoxy adhesive (base agent 1) diluted with 25 cc of n-butyl cellosolve was used.
g, curing agent 1 g: manufactured by Konishi Co., Ltd., trade name "Bond E")
Is formed by spin coating to a thickness of 200 nm.

Alternatively, a similar adhesive layer 65 may be formed by forming a polyimide film on the transfer substrate 67 and spraying the diluted two-part epoxy adhesive described above by a spray method.

Thereafter, the solvent contained in the adhesive layer 65 was dried at 80 ° C. for 180 seconds, and then, as shown in FIG. In a flat state, the pieces are once bonded by air-pressing at a pressure of 1 kgf / cm ² . At this time, the alignment film 63 a on the upper surface of the polymer wall 64 is brought into contact with the adhesive layer 65. Finally, the signal line substrate 68a and the transfer substrate 6
Peel 7 off.

As a result, as shown in FIG. 5D, the adhesive layer 65 is transferred from the transfer substrate 67 to the alignment film 63a on the upper surface of the polymer wall 64 of the signal line substrate 68a. The conditions required for the transfer substrate 67 are that there is no deterioration of the adhesive resin due to the solvent and that there is no obstacle to the transfer of the adhesive resin.

The thus prepared signal line substrate 68a has
Scanning line substrate 68b having a thickness of 1.1 mm and a Young's modulus E
With a pressure of 1 kg / cm ² while evacuating.
Bonded over time. The adhesive force G of the adhesive layer 65
Is 0.02 kg / mm.

The signal line substrate 68a thus bonded is
Liquid crystal is injected into the gap between the liquid crystal cell and the scanning line substrate 68b to complete a liquid crystal cell as shown in FIG.

In this liquid crystal cell, no cavity was generated, and the size 裂 of the crack generated between the adhesive layer 65 and the scanning line substrate 68b was 5.9 mm. This value is longer than the typical length λ = 5 mm of the surface irregularities generated on the scanning line substrate 68b.

The value of L in the case where Γ = 5 mm was obtained from the above Expression 14, and it was L = 0.253 mm. That is, according to the above example, it is understood that no cavity is generated when the critical length 亀 of the crack is longer than the typical length λ of the unevenness on the substrate surface. The manufacturing conditions such as the size of each part shown in the above example satisfy the conditions shown in Expression 12.

For comparison with the above example, the polymer wall 64
When a pitch L of 0.25 mm was set to 0.25 mm and a liquid crystal cell was prototyped by the same process, a cavity as shown in FIG. 14 was generated. In this case, the size 裂 of the crack generated between the adhesive layer 65 and the scanning line substrate 68b was 4.7 mm. This value is shorter than the typical length λ = 5 mm of the surface irregularities generated on the scanning line substrate 68b. From this, the critical length 裂 of the crack is the typical length λ of the substrate surface irregularities.
It has been shown that cavities occur when shorter.

[0163]

As described above, the method for manufacturing a liquid crystal display element according to the first aspect includes a step of forming a wall-shaped spacer on one of a pair of substrates and a step of bonding the pair of substrates by pressure bonding. A, the thickness of the substrate is A, the Young's modulus of the substrate is E, the pitch at which the wall-shaped spacers are arranged is L, the pressure at which the substrate is crimped in the process is P, the cells allowed for the liquid crystal display element. When the amount of change in thickness of the ^{V, PL 4 / EA 3 ≦} Vπ 5/48 is established.

Thus, even if pressure P is applied in the step of bonding a pair of substrates by pressure bonding, the amount of change in cell thickness due to this pressure P falls within an allowable range. Therefore, there is an effect that the uniformity of the cell thickness is improved and a liquid crystal display element free from display defects can be provided.

A method of manufacturing a liquid crystal display element according to claim 2, wherein a step of forming a wall-shaped spacer having a pitch L and a height H on one of a pair of substrates, and a step of pressing the other substrate at a pressure P, and the Young's modulus of the other substrate E, when a thickness of ^{a, PL 4 / EA 3 H} ≦ π 5/48 is established.

Thus, after forming the wall-shaped spacer on one of the pair of substrates, even if pressure is applied to the other substrate such as the other substrate or the transfer substrate, a pressure is applied to this substrate. The amount of deflection of the substrate due to this pressure can be kept within a range where the substrate on which the wall-shaped spacer is formed and the other substrate do not come into contact with each other. As a result, it is possible to provide a liquid crystal display element free from display defects and transfer defects due to substrate deformation.

In the liquid crystal display device according to the present invention, assuming that the withstand pressure limit pressure of the liquid crystal display device is P and the displacement of the cell thickness at which the change of the liquid crystal alignment occurs is V, the pitch L of the wall-shaped spacer, the height H, The width W and the Young's modulus E are such that PLH ² / EW ² ≦ 2V is satisfied.

According to the above configuration, when an external force such as an impact is applied, if the magnitude of the external force is smaller than the withstand pressure limit pressure P, the displacement of the cell thickness caused by the external force becomes
It falls within a range that does not affect the change in the liquid crystal alignment. Thereby, there is an effect that a liquid crystal display element having excellent shock resistance can be provided.

In the liquid crystal display element according to the fourth aspect, a resin layer is provided on at least one of the substrates, the thickness of the resin layer is h _P , the height of the main portion of the wall-shaped spacer is h _W , and the Young's modulus of the resin layer is Is E _P and the Young's modulus of the wall-shaped spacer main portion is E _W , H = h _P + h _W , E = (E _P h _P + E _W h _W ) / (h _P
+ H _W ).

According to the above configuration, even in a configuration having a resin layer such as a color filter, for example, the thickness of the resin layer and the height of the wall-shaped spacer are adjusted according to the respective Young's moduli. The amount of displacement of the cell thickness when an external force smaller than the withstand pressure limit pressure is applied can be kept within a range that does not affect the change in the liquid crystal alignment. As a result, there is an effect that a liquid crystal display element having excellent shock resistance can be provided.

In the liquid crystal display element according to the fifth aspect, the thickness of the substrate is A, the Young's modulus of the substrate is E, the pitch of the wall spacer is L, the adhesive force between the pair of substrates is G, and the unevenness of the substrate surface is provided. Is the length of λ and the height of the unevenness is Δ, GλL ⁶ / Δ ² A ⁶ E ≧ 0.05 holds.

According to the above configuration, even if unevenness is generated on the substrate surface due to various factors in the manufacturing process, the influence of the peeling stress generated between the substrates can be reduced. As a result, it is possible to provide a liquid crystal display element having no bubbles or cavities.

A method of manufacturing a liquid crystal display element according to claim 6, wherein a pair of substrates each having at least an electrode and an alignment control layer are bonded at a distance by a striped wall spacer. A step of forming a wall-shaped spacer on one of the pair of substrates and a step of bonding the pair of substrates by pressure bonding, wherein the thickness of the substrate is A, the Young's modulus of the substrate is E, Assuming that the pitch at which the spacers are arranged is L and the pressure at which the substrate is pressed in the above step is P, the following holds: PL ⁴ / EA ³ ≦ 0.00065 [mm].

As a result, the amount of change in cell thickness in the step of bonding a pair of substrates by pressure bonding can be kept within a range that does not affect the change in liquid crystal alignment (within 0.1 μm). This has the effect that the liquid crystal display element with improved display performance and no display defects can be provided.

A liquid crystal display element according to claim 7, wherein a pair of substrates each having at least an electrode and an alignment control layer are bonded to each other at intervals by a striped wall spacer. When the withstand pressure limit pressure is P, the pitch L, height H, width W, and Young's modulus E of the above-mentioned wall-shaped spacer satisfy PLH ² / EW ² ≦ 0.2 [μm].

As a result, if the magnitude of the external force is smaller than the withstand pressure limit pressure P, the displacement of the cell thickness caused by the external force does not affect the change in the liquid crystal alignment (0.1 to 0.1).
(within μm). As a result, there is an effect that a liquid crystal display element having excellent shock resistance can be provided.

The liquid crystal display element according to the present invention is a liquid crystal display element in which a pair of substrates each having at least an electrode and an alignment control layer are bonded at intervals by a striped wall spacer. A,
Assuming that the pitch of the wall-shaped spacer is L, the configuration holds that L ⁶ / A ⁶ ≧ 0.00015.

Thus, even if irregularities are generated on the substrate surface due to various factors in the manufacturing process, the influence of the peeling stress generated between the substrates can be reduced. As a result, it is possible to provide a liquid crystal display element having no bubbles or cavities.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic structure of a liquid crystal cell according to an embodiment of the present invention.

FIG. 2 Deformation amount of substrate with respect to pitch of polymer wallξ
It is a graph which shows the result of having measured the maximum value of (x).

FIG. 3 is a cross-sectional view showing a more specific configuration example of the liquid crystal cell according to the embodiment.

FIG. 4 is a cross-sectional view illustrating a configuration of a liquid crystal cell according to another embodiment of the present invention.

5 (a) to 5 (d) are cross-sectional views showing steps of manufacturing the liquid crystal cell shown in FIG.

FIG. 6 is a cross-sectional view illustrating a configuration of a liquid crystal cell according to still another embodiment of the present invention.

FIG. 7 is a graph showing the relationship between the pitch of polymer walls and shock resistance.

FIG. 8 shows a configuration of a liquid crystal cell according to still another embodiment of the present invention, in which a relatively large unevenness is present on the surface of the substrate, so that a crack is generated between the polymer wall and the substrate. FIG.

FIG. 9 is a perspective view showing a state in which cracks are generated between the polymer wall and the substrate due to the presence of relatively small irregularities on the substrate surface in the liquid crystal cell.

FIG. 10 is a graph showing the relationship between the pitch of a polymer wall and the length of a cavity.

FIG. 11 is a cross-sectional view illustrating a schematic configuration of an example of a conventional ferroelectric liquid crystal display device.

FIG. 12 is a schematic diagram illustrating an electric field response of ferroelectric liquid crystal molecules.

FIG. 13 is a schematic diagram illustrating a state of switching of ferroelectric liquid crystal molecules.

FIG. 14 is a plan view showing a liquid crystal cell having a cavity.

[Explanation of symbols]

 48a / 48b Substrate 40 Polymer wall (wall-like spacer)

Continuation of the front page (71) Applicant 390040604 United Kingdom THE SECRETARY OF STATE FOR DEFENSE IN HER BRITANNIC MAJES TY'S GOVERNMENT OF THE THE UNERED KINGDOM OF GREEN BRIGHTNOR BRIGHTNOR BIRTH Road (No address) Defense Evaluation and Research Agency (72) Inventor Mitsuhiro Shigeta 22-22 Nagaikecho, Abeno-ku, Osaka, Osaka Inside Sharp Corporation (72) Inventor Hideki Uchida Osaka, Osaka 22-22, Nagaike-cho, Abeno-ku, Sharp Corporation (72) Inventor Kazuhiko Tamai, 22-22, Nagaike-cho, Abeno-ku, Osaka City, Osaka Nobuyuki Ito 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Japan, inside Sharp Corporation (72) Inventor Yuka Sasaki 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka inside Sharp Corporation (72) Inventor Kabe Masaaki Shosha Co., Ltd. 22-22 Nagaikecho, Abeno-ku, Osaka City (72) Inventor Tomoaki Furukawa Sharp Co., Ltd. 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka (72) Inventor Yoshihiro Sakari Osaka, Osaka (22) Inventor Hisashi Akiyama 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka

Claims (8)

[Claims] 1. A method of manufacturing a liquid crystal display device, comprising: a pair of substrates each having at least an electrode and an orientation control layer, each of which is bonded at intervals by a stripe-shaped wall spacer. A step of forming a spacer, and a step of bonding a pair of substrates by pressure bonding, wherein the thickness of the substrate is A, the Young's modulus of the substrate is E, the pitch at which the wall-shaped spacers are arranged is L, When the pressure at the time of crimping the substrate P, and the variation of the cell thickness that is acceptable for the liquid crystal display device is V, the manufacture of liquid crystal display element characterized by ^{PL 4 / EA 3 ≦ Vπ 5} /48 is established Method. 2. A method of manufacturing a liquid crystal display device comprising a pair of substrates each having at least an electrode and an orientation control layer, each of which is bonded at a distance by a striped wall spacer. L, a step of forming a wall-shaped spacer having a height H, and a step of pressing another substrate with a pressure P on the substrate on which the wall-shaped spacer has been formed, wherein the Young's modulus of the other substrate is E, When the thickness of the a, a method of manufacturing a liquid crystal display element characterized by ^{PL 4 / EA 3 H ≦ π} 5/48 is established. 3. A liquid crystal display device in which a pair of substrates each having at least an electrode and an orientation control layer are bonded at intervals by a striped wall spacer, wherein the liquid crystal display device has a withstand pressure limit of P, A liquid crystal characterized in that the pitch L, height H, width W, and Young's modulus E of the wall-shaped spacer satisfy PLH ² / EW ² ≦ 2V, where V is the displacement of the cell thickness at which the change in alignment occurs. Display element. 4. A resin layer is provided on at least one of the substrates, the thickness of the resin layer is h _P , the height of the main portion of the wall-shaped spacer is h _W , the Young's modulus of the resin layer is E _P , and the wall-shaped spacer is Assuming that the Young's modulus of the main part is E _W , H = h _P + h _W , E = (E _P h _P + E _W h _W ) / (h _P
+ H _W ). The liquid crystal display device according to claim 3, wherein 5. A liquid crystal display device in which a pair of substrates each having at least an electrode and an orientation control layer are bonded at intervals by a striped wall spacer.
The thickness of the substrate is A, the Young's modulus of the substrate is E, the pitch of the wall spacer is L, the adhesive force between the pair of substrates is G, the length of the irregularities on the substrate surface is λ, and the height of the irregularities is A liquid crystal display element characterized in that, when Δ, GλL ⁶ / Δ ² A ⁶ E ≧ 0.05 is satisfied. 6. A method for manufacturing a liquid crystal display device, comprising a pair of substrates each having at least an electrode and an alignment control layer, each of which is bonded at a distance by a striped wall spacer. A step of forming a spacer, and a step of bonding a pair of substrates by pressure bonding, wherein the thickness of the substrate is A, the Young's modulus of the substrate is E, the pitch at which the wall-shaped spacers are arranged is L, A method for manufacturing a liquid crystal display element, wherein PL ⁴ / EA ³ ≦ 0.00065 [mm] is satisfied, where P is the pressure at which the substrate is pressed. 7. In a liquid crystal display device in which a pair of substrates each having at least an electrode and an orientation control layer are bonded at a distance by a stripe-shaped wall-shaped spacer, a pressure limit pressure of the liquid crystal display device is P. A pitch L, a height H, a width W, and a Young's modulus E of the wall-like spacer satisfy PLH ² / EW ² ≦ 0.2 [μm]. 8. A liquid crystal display device in which a pair of substrates each having at least an electrode and an alignment control layer are bonded to each other at intervals by a striped wall spacer.
A liquid crystal display device characterized in that when the thickness of the substrate is A and the pitch of the wall-like spacer is L, L ⁶ / A ⁶ ≧ 0.00015 is satisfied.