JP3895447B2 - Liquid crystal display element and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a liquid crystal display element that is excellent in impact properties and realizes a good display quality, and a manufacturing method thereof.
[0002]
[Prior art]
  2. Description of the Related Art Conventionally, there is known a liquid crystal display element in which a pair of substrates are bonded to each other so that a surface on which an electrode is formed is on the inside and liquid crystal is sealed in a gap therebetween. In such a liquid crystal display element, when the distance between the opposing substrates changes as a result of deformation of the substrate due to external pressure, the threshold voltage changes, the electrode shorts between the opposing substrates, or the disorder of the orientation of the liquid crystal molecules. As a result, good display becomes impossible. For this reason, in order to keep the distance between a pair of substrates constant, a method of arranging spacers between the substrates is known. Conventionally, (1) a method of dispersing spherical particles, (2) an organic or inorganic system One of the methods for forming the column is generally used.
[0003]
  Specific examples of the method (1) include a dry method in which pearl particles made of an organic resin such as a divinylbenzene polymer are dispersed in a nitrogen atmosphere and sprayed on a substrate, or the pearl particles are alcoholized. A method of mixing in a solution or the like and spraying it on a substrate in a mist form is known.
[0004]
  However, the method (1) has the following problems. The first problem is that the fine particles have the property of aggregating with each other, so that it is difficult to evenly distribute them on the substrate and it is difficult to achieve a uniform cell thickness. As a second problem, since it is difficult to control the arrangement of the fine particles, the fine particles dispersed in the pixel portion may cause an alignment defect, which may deteriorate the display quality. Can be mentioned. Furthermore, the third problem is that it is difficult to obtain sufficient strength against the external pressure because the substrate is supported by point contacts with the pearl particles as the spacer.
[0005]
  On the other hand, in the method (2), more specifically, an organic or inorganic film is formed to a predetermined thickness, and a resist film is further formed thereon, and then mask exposure is performed to form pillars as spacers. It is a method of forming. Instead of the resist film, for example, a photosensitive organic resin such as photosensitive polyimide or photosensitive acrylic resin can be used.
[0006]
  Thus, in the method (2), the pillars can be selectively formed outside the pixels. In addition, it has the advantage that the contact surface between the substrate and the pillar can be formed in an arbitrary pattern, and is superior in the uniformity of cell thickness, strength against external pressure, and display quality compared to the method (1). Yes.
[0007]
  In recent years, ferroelectric liquid crystal has attracted attention as a liquid crystal material. Ferroelectric liquid crystal has excellent properties such as being capable of high-speed response due to spontaneous polarization, but it has more regular alignment of molecules. Since it has a structure close to a crystal, it has a problem that it is difficult to return to its original state when the regularity of molecular orientation is disturbed by external pressure, that is, it is weak against impact. For this reason, in order to overcome the above-described problems of the ferroelectric liquid crystal, it is necessary to have a substrate structure with excellent impact properties. As a method for manufacturing such a liquid crystal display element, the method (2) is considered to be a more promising candidate compared to the method (1).
[0008]
[Problems to be solved by the invention]
  In the configuration of the conventional liquid crystal display element, (A) after forming an alignment control layer on an insulating substrate, a spacer is formed on the alignment control layer, and the top of the spacer on one substrate and the other substrate are formed. A structure in which a pair of substrates are bonded together by adhesion to an orientation control layer. (B) After forming a spacer on an insulating substrate, an orientation control layer is formed so as to cover the spacer, and the top of the spacer on one substrate And a liquid crystal display element having a structure in which a pair of substrates are bonded together by bonding the alignment control layer of the first substrate to the alignment control layer of the other substrate.
[0009]
  However, the above-described conventional configuration has the following various problems.
[0010]
  First, in (A), since the spacer is formed on the orientation control layer, there is a problem that the manufacturing process of the spacer may cause contamination, alteration, destruction, etc. of the orientation control layer. Spacers are formed on the substrate after the alignment treatment by photolithography using a photosensitive polyimide or a photoresist, but the solvent used in this photolithography process has an adverse effect on the alignment control layer. There is a possibility of effect. In such a case, since the alignment control ability of the alignment control layer is reduced, the alignment of liquid crystal molecules becomes non-uniform, and a reduction in display quality is inevitable. Further, considering that the alignment control layer is not affected, there is a problem that the material of the spacer or the alignment control layer is restricted.
[0011]
  On the other hand, in (B), since the alignment control layer is softened by heating under pressure in order to bond the alignment control layers to each other, there is a problem that the alignment control force of the alignment control layer may be adversely affected. . In such a case, since the alignment control ability of the alignment control layer changes, the alignment of the liquid crystal molecules becomes non-uniform and the display quality is inevitably lowered. In addition, when organic solvent-soluble polyimide is used as the orientation control layer, imidization does not proceed by heating compared to the polyamic acid type, so there is a problem that sufficient adhesive strength cannot be obtained, and there are restrictions on the orientation control layer material. Arise. Note that in (A), a pair of substrates is bonded to each other by adhesion between a spacer on one substrate and an orientation control layer on the other substrate. Therefore, since the spacer is softened instead of the orientation control layer, display quality is not deteriorated due to softening of the orientation control layer, which is a problem in (B).
[0012]
  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display element that has a uniform cell thickness, has sufficient shock resistance, and can realize good display quality without unevenness. And providing a manufacturing method thereof.
[0013]
[Means for Solving the Problems]
  BookIn order to solve the above problems, a liquid crystal display element according to the invention is a liquid crystal display element in which liquid crystal is sealed between a pair of substrates, at least one of which is light transmissive, and at least one of the pair of substrates.On the insulating film formed so as to cover the insulating substrate and the plurality of electrodes.A columnar or wall-like spacer having a uniform height, and the one substrate excluding a portion located at the top of the spacerThe surface of the insulation filmTo coverDepending on the material repelled by the spacerAn alignment control layer is provided, and a portion located at the top of the spacer is bonded to the alignment control layer of the other substrate, whereby the pair of substrates are bonded to each other.
[0014]
  According to said structure, a pair of board | substrate is bonded together by the column-shaped or wall-shaped spacer which has uniform height, maintaining a uniform space | interval. In addition, since the pair of substrates forms the alignment control layer after the spacer is formed, the display quality deteriorates due to contamination, alteration, destruction, etc. of the alignment control layer due to the spacer formation process. Material constraints can be avoided.
[0015]
  Further, in the above configuration, the orientation control layer is provided so as to cover the substrate surface except for the top portion of the spacer, and a pair is formed by adhesion between the top portion of the spacer formed on one substrate and the orientation control layer of the other substrate. The substrate is attached. For this reason, since the spacer is softened without softening the alignment control layer, it is possible to avoid deterioration in display quality due to softening of the alignment control layer and insufficient adhesive strength that occur when the alignment control layers are bonded to each other.
[0016]
  As described above, according to the above-described configuration, it is possible to provide a liquid crystal display element that can make the cell thickness uniform with higher accuracy than before, and has good display quality without unevenness and excellent shock resistance.
[0017]
  According to the above configuration,By the material repelled by the spacer so as to cover the surface of the insulating film on one substrateSince the orientation control layer is provided, the spacer repels the orientation control layer.
[0018]
  As a result, when the orientation control layer is provided, the spacer repels the orientation control layer even if the orientation control layer is applied by spin coating or roll coating so as to cover the entire upper layer of the insulating substrate on which the spacer is formed. Therefore, the orientation control layer can be applied so as to cover the upper layer of the insulating substrate other than the spacer formation region. Accordingly, since there is no need to remove the alignment control layer on the spacer as in the prior art, the alignment control layer is not contaminated or damaged, and a liquid crystal display element that realizes good display quality with a simple manufacturing method is provided. Can offerThe
[0019]
  Main departureThe pair of substrates are bonded together by adhesion between the spacer on one substrate and the orientation control layer on the other substrate, so that the orientation control layer only needs to be formed on the insulating substrate except at least the top of the spacer. The alignment control layer may or may not be formed on the spacer side surface.
[0020]
  BookThe liquid crystal display element according to the invention isIn addition to the above configuration,The spacer is made of a photosensitive organic resin.
[0021]
  According to said structure, a spacer consists of photosensitive organic resin. When the spacer material is an inorganic or non-photosensitive organic resin, the spacer is formed by photolithography using a photoresist. However, in the case of a photosensitive organic resin, it is not necessary to use a photoresist, and therefore, a simpler manufacturing method is used. It is possible to provide a liquid crystal display element excellent in display quality and shock resistance.
[0022]
  BookThe liquid crystal display element according to the invention isIn addition to the above configuration,The spacer is a region between a plurality of electrodes on the one substrate.On the insulation filmIt is arranged and has optical isotropy.
[0023]
  According to the above configuration, the spacer is formed outside the pixel region. For this reason, it is possible to avoid a decrease in aperture ratio and display quality that occurs when a spacer is formed in a pixel. Furthermore, since the spacer has optical isotropy, it can function as a black matrix.
[0024]
  BookThe liquid crystal display element according to the invention isIn addition to the above configuration,The liquid crystal is a ferroelectric liquid crystal.
[0025]
  According to the above configuration, since the ferroelectric liquid crystal has spontaneous polarization and can have a high-speed response due to its memory property, for example, a liquid crystal display element capable of displaying a large-capacity and high-definition image is provided. Can be provided.
[0026]
  Ferroelectric liquid crystals, for example, have a molecular alignment close to that of crystals compared to nematic liquid crystals, so that once the regularity of molecular orientation is disturbed by external pressure, it is difficult to return to its original state, that is, it is vulnerable to impact. However, according to the above configuration, sufficient substrate strength is realized, so that the above-mentioned drawbacks are eliminated, and as a result, a liquid crystal display element that exhibits excellent characteristics of ferroelectric liquid crystal is provided. It becomes possible to do.
[0027]
  BookIn order to solve the above-described problems, a method for manufacturing a liquid crystal display element according to the invention is the method for manufacturing a liquid crystal display element in which liquid crystal is sealed between a pair of substrates each having at least one light transmission property. On at least one of the substratesOn the insulating film formed to cover the insulating substrate and the plurality of electrodesA first step of forming a plurality of columnar or wall-like spacers of uniform height, and the one substrate except for a portion located at the top of the spacerInsulating film surfaceTo coverDepending on the material repelled by the spacerThe method includes a second step of forming an orientation control layer and a third step of bonding a portion located on the top of the spacer to the orientation control layer of the other substrate.
[0028]
  According to the above method, first, a spacer is formed on the upper layer of the insulating substrate in the first step. In addition, an electrode, a light shielding layer, an insulating film, or the like can be formed on each substrate as needed before or after the first step. Thereafter, in the second step, an orientation control layer is formed so as to cover the upper layer of the insulating substrate excluding the spacer top. Thus, by forming the spacer prior to the formation of the alignment control layer, the alignment control layer is prevented from being contaminated or damaged by the solvent or the like used in the spacer formation process.
[0029]
  As a result, it is possible to provide a liquid crystal display element capable of realizing good display quality without unevenness. Further, by selectively forming the orientation control layer so as to cover the upper layer of the insulating substrate other than the top of the spacer, the pair of substrates is bonded to the top of the spacer of one substrate and the orientation control layer of the other substrate. It is pasted together. In this way, by selectively forming the alignment control layer so as to cover the insulating substrate upper layer other than the top of the spacer, the display quality deteriorates due to the softening of the alignment control layer that occurs when the alignment films are bonded to each other, and the adhesive strength is insufficient. Can be avoided.
[0030]
  BookIn the liquid crystal display element manufacturing method according to the invention, in the second step,An orientation control layer is formed by a material repelled by the spacer so as to cover the surface of the insulating film.It is characterized by forming.
[0031]
  According to the above method, in order to selectively form the alignment control layer outside the spacer formation region, it is utilized that the spacer repels the alignment control layer.
[0032]
  As a method of forming the alignment control layer so as to cover the insulating substrate upper layer outside the spacer formation region, first, the alignment control layer is formed so as to cover the entire insulating substrate upper layer including the spacer, and then the spacer is formed by photolithography or the like. A method of removing the upper alignment control layer is mentioned. However, in the case of this method, there is a problem that good display quality cannot be obtained because the alignment control layer is contaminated or damaged by the photolithography process.
[0033]
  However, in the method of the present invention, the spacer repels the alignment control layer even if the alignment control layer is applied by spin coating or roll coating so as to cover the entire upper layer of the insulating substrate on which the spacer is formed. The orientation control layer can be applied so as to cover the upper layer of the insulating substrate other than the spacer formation region. Therefore, since there is no need to remove the alignment control layer above the spacer as in the conventional method, the alignment control layer is not contaminated or damaged, and good display quality can be realized with a simple manufacturing method. It becomes possible.
[0034]
  In order for the spacer to repel the orientation control layer, the wettability of the orientation control layer with respect to the spacer surface may be made worse than that with respect to the region on the insulating substrate other than the spacer by the following method.
(1) Select a spacer material or an orientation control layer material that will deteriorate the wettability of the orientation control layer with respect to the spacer.
(2) Add surfactant to spacer or orientation control layer material
(3) Surface treatment with insulating substrate after spacer formation
  In the present invention, the pair of substrates are bonded together by adhesion between the spacer on one substrate and the alignment control layer on the other substrate. Therefore, if the alignment control layer is formed at least on the insulating substrate excluding the top of the spacer. The alignment control layer may or may not be formed on the side surface of the spacer.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
  One embodiment of the present invention will be described with reference to FIGS. 1 and 2 as follows.
[0036]
  FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid crystal display element according to an embodiment of the present invention. The present liquid crystal display element has a configuration in which a pair of substrates 10 and 20 are bonded to each other and a liquid crystal 7 is sealed in a gap therebetween.
[0037]
  The substrate 10 includes an insulating substrate 1a, a plurality of electrodes 2a arranged in parallel to each other, a light shielding layer 3a, and an insulating film 4a formed so as to cover the insulating substrate 1a, the electrode 2a, and the light shielding layer 3a. And a spacer 6 formed on the surface of the insulating film 4a, and an orientation control layer 5a formed so as to cover the surface of the insulating film 4a excluding the top of the spacer 6.
[0038]
  The substrate 20 includes an insulating substrate 1b, a plurality of electrodes 2b arranged in parallel to each other, an insulating film 4b, and an orientation control layer 5b stacked on the surface of the insulating film 4b. The substrates 10 and 20 are bonded together by bonding the top of the spacer 6 formed on the insulating substrate 1a and the orientation control layer 5b formed on the insulating substrate 1b.
[0039]
  The insulating substrates 1a and 1b are made of a transparent material such as glass or plastic. In addition, as the electrodes 2a and 2b, transparent electrodes made of ITO (Indium Tin Oxide) are generally used, but electrodes using other metals may be used. The light shielding layer 3a is formed of a metal such as Cr, Mo, Al, or an opaque organic resin.
[0040]
  For the liquid crystal 7, a ferroelectric liquid crystal composition is used. Since the ferroelectric liquid crystal has excellent characteristics such as a high-speed response and a memory property, a large-capacity and high-definition image can be displayed.
[0041]
  The liquid crystal display element of the present embodiment having the above-described configuration is manufactured by the following steps. That is, first, a film having a thickness of about 100 nm is formed on the surface of the insulating substrate 1a with a metal such as molybdenum or an opaque organic resin, and this film is patterned by photolithography, as shown in FIG. Then, a light shielding layer 3a having a predetermined pattern is formed.
[0042]
  Next, an ITO film having a thickness of about 100 nm is formed thereon by sputtering, and this is patterned by photolithography to form the electrode 2a. As a result, as shown in FIG. 2B, the light shielding layer 3a is disposed along both ends of the electrode 2a.
[0043]
  Furthermore, on this, SiO₂As shown in FIG. 2C, an insulating film 4a having a uniform surface is formed. The insulating film 4a can be omitted in some cases.
[0044]
  On the insulating film 4a, for example, a negative photosensitive acrylic resin V-259 manufactured by Nippon Steel Chemical Co., Ltd. is applied by spin coating so that the film thickness after firing becomes 1.5 μm. Next, a photomask is applied between the light-shielding layer 3a and the region where the electrode 2a is not formed, and a spacer is to be formed, and UV irradiation is performed to remove the non-exposed portion. As a result, spacers 6 are formed as shown in FIG. The spacer 6 can be formed in an arbitrary shape such as a columnar shape, a wall shape, or a stripe shape by variously changing the pattern and arrangement position of the photomask.
[0045]
  Next, an alignment film PSI-A-2101 manufactured by Chisso was applied by spin coating so as to have a film thickness of 50 nm, baked at about 200 ° C. for 1 hour, and then subjected to rubbing treatment on the surface, as shown in FIG. ), The orientation control layer 5a is formed.
[0046]
  As described above, when the alignment control layer 5a is formed, the spacer 6 repels the alignment control layer material, so that the alignment control layer 5a is formed on the substrate 10 excluding the top of the spacer 6 as shown in FIG. It can be provided so as to cover the upper layer. This will be described in detail later.
[0047]
  Through the above steps, the substrate 10 can be formed. For the substrate 20, the electrode 2b, a light shielding layer (not shown), and the insulating film 4b are sequentially formed on the insulating substrate 1b by the same process as described above, and the orientation control layer 5b is formed on the insulating film 4b. It is produced by doing.
[0048]
  Next, these substrates 10 and 20 are opposed so that the rubbing directions of the orientation control layers 5a and 5b are the same, and 0.9 kg / cm at about 180 ° C. for 1 hour.²The spacer 6 and the orientation control layer 5b are adhered by applying the pressure of In addition, substrate 1
The liquid crystal display element is completed by sealing the liquid crystal 7 in the gap between 0 and 20.
[0049]
  The liquid crystal display element actually produced by the above process was able to make the cell thickness uniform with an accuracy within ± 0.03 μm. Further, since the vicinity of the spacer 6 is hidden by the light shielding layer 3a and the light shielding layer on the substrate 20 side, uniform orientation, switching characteristics, and a high aperture ratio can be obtained in the pixel display portion.
[0050]
  In addition to the negative photosensitive organic resin described above, the spacer 6 can be made of non-photosensitive organic resin such as polyimide or acrylic resin, or metal such as Cr, Mo, or Al. However, in the case of the photosensitive organic resin, since a photoresist is unnecessary, there is an advantage that it can be manufactured more easily and at low cost. The spacer 6 can be formed in any region on the insulating substrate 1a. However, it is desirable to form the spacer 6 outside the pixel display region in order not to deteriorate the display quality.
[0051]
  In the above configuration, the configuration in which the spacer 6 is provided only on the substrate 10 side has been described. However, the necessary spacer 6 is provided in a distributed manner on both the substrates 10 and 20, and the top of the spacer on one substrate is the other. It is also possible to adopt a configuration in which the substrates 10 and 20 are bonded to each other by adhering to an orientation control layer in a region where there is no spacer in the substrate.
[0052]
  Further, the insulating films 4a and 4b are not essential, and may be omitted if no leak current occurs between the substrates 10 and 20. In addition to the various films described above, an overcoat film or the like may be formed as necessary.
[0053]
  As described above, the orientation control layer 5a is formed so as to cover the region other than the top of the spacer 6 and the surface of the insulating film 4a. PSI-A-2101 used as the orientation control layer 5a has poor wettability with respect to V-259 used as the spacer 6, and SiO used as the insulating film 4a.₂Good for. For this reason, when the orientation control layer 5a is spin-coated, the orientation control layer 5a is not repelled on the surface of the spacer 6, but is uniformly formed in a region other than the spacer 6 and on the surface of the insulating film 4a. It is also possible to selectively form the orientation control layer 5a in a region other than the spacer 6 and on the surface of the insulating film 4a by screen printing.
[0054]
  As described above, the liquid crystal display element according to the present embodiment includes the pair of substrates 10 and 20, and one substrate 10 is insulated on the insulating substrate 1 a on the electrode 2 a, the light shielding layer 3 a, and if necessary. After the film 4a is formed, a spacer 6 is further formed on these upper layers, and the orientation control layer 5a is laminated so as to cover the upper layer of the insulating film 4a in a region other than the spacer 6. The other substrate 20 has a configuration in which the orientation control layer 5b is laminated on the upper layer of the insulating substrate 1b so as to cover the entire upper layer on which the electrode 2b and, if necessary, the insulating film 4b are formed.
[0055]
  Since the orientation control layer 5a is formed after the formation of the spacer 6, there is no contamination, alteration, destruction, etc. of the orientation control layer 5a due to the spacer formation step, so that good display quality can be obtained.
[0056]
  The orientation control layer 5a is formed so as to selectively cover the region other than the spacer 6 and the upper layer of the insulating film 4a. As a result, the substrates 10 and 20 are bonded together by bonding the top of the spacer 6 on the insulating substrate 1a and the orientation control layer 5b on the insulating substrate 1b. In other words, the substrate may be bonded by softening only the spacer 6 without softening the orientation control layer. At the heating temperature of 180 ° C. in the bonding step, the orientation control layer is not softened, and only the spacer 6 is softened. Further, the firing temperature of the orientation control layer is lower than 200 ° C. Therefore, the heating in the bonding process does not affect the alignment regulating force of the alignment control layer. For this reason, it is possible to avoid a decrease in the alignment control ability due to the softening of the alignment control layer, which has been apt to occur when bonding the alignment films between the conventional alignment films, and to prevent restrictions on the alignment control layer material. It is possible to provide a liquid crystal display element excellent in shock resistance.
[0057]
  Further, the spacer 6 is formed of an optically isotropic material, that is, a material having no refractive index anisotropy, and the spacer 6 is completely adhered to the facing orientation control layer 5b of the substrate 20 without a gap. As a result, the spacer 6 is quenched under crossed Nicols. That is, under the above conditions, the spacer 6 also functions as a black matrix, so that an effect of improving the contrast by shielding the portion other than the pixel region is obtained.
[0058]
  Further, in the vicinity of the spacer 6, the alignment and switching characteristics of the liquid crystal become uneven and display unevenness may occur. However, according to the configuration of this embodiment, the vicinity of the spacer 6 is hidden by the light shielding layer 3 a. Therefore, even if slight display unevenness occurs, the actual display state is not affected and high display quality can be obtained.
[0059]
  [Comparative Example 1]
  Here, a liquid crystal display element manufactured by a conventional process is cited as a comparative example, and the comparison with the liquid crystal display element of the present embodiment described above is performed. In addition, the same code | symbol is attached | subjected to the structure similar to the structure demonstrated by above-described embodiment, and the detailed description is abbreviate | omitted.
[0060]
  In the conventional liquid crystal display device, as shown in FIG. 3, after the spacer 6 is formed, the orientation control layer 5a is formed so as to cover the entire upper layer of the spacer 6 and the insulating film 4a. The alignment control layer 5a on the conductive substrate 11a and the alignment control layer 5b on the insulating substrate 1b are bonded together.
[0061]
  The manufacturing process of the conventional liquid crystal display element is as follows.
[0062]
  The electrode 2a, the light shielding layer 3a, the insulating film 4a, and the spacer 6 are formed on the surface of the insulating substrate 11a by a process similar to the process described with reference to FIGS. 2 (a) to 2 (d).
[0063]
  Next, this insulating substrate 11a is immersed in an isopropyl solution of a silane coupling agent SH6020 manufactured by Toray Dow Corning, and then washed with water. Next, an alignment film PSI-A-2101 manufactured by Chisso Corporation was applied by a spin coating method so as to have a film thickness of 50 nm, baked at about 200 ° C. for 1 hour, and then subjected to rubbing treatment on the surface, and the alignment control layer 5a Form. The substrate 11 is manufactured through the above steps.
[0064]
  Next, these substrates 11 and 20 are made to face each other so that the rubbing directions of the orientation control layers 5a and 5b are the same, and 0.9 kg / cm at about 250 ° C. for 1 hour.²The orientation control layers 5a and 5b are adhered by applying a pressure of Further, the liquid crystal display element is completed by sealing the liquid crystal 7 in the gap between the substrates 11 and 20.
[0065]
  As described above, in the liquid crystal display element according to Comparative Example 1, the wettability of the surface of the spacer 6 is improved by the silane coupling agent treatment, and the alignment control layer 5a covers the entire upper layer of the spacer 6 and the insulating film 4a. This is different from the embodiment of the present invention in that the substrates 11 and 20 are bonded by the orientation control layers 5a and 5b as a result.
[0066]
  Since the orientation control layer 5a is formed after the spacer 6 is formed, the orientation control layer 5a is not contaminated, altered, destroyed, or the like in the spacer forming step, as in the present embodiment.
[0067]
  However, the alignment control layer 5a of the comparative example is formed so as to cover the upper layer of the spacer 6 and the insulating film 4a. As a result, the substrates 11 and 20 are bonded together by softening the orientation control layer 5a on the insulating substrate 11a and the orientation control layer 5b on the insulating substrate 1b. For this purpose, the heating temperature in the bonding step necessary is 250 ° C., which is higher than the firing temperature of the orientation control layer, 200 ° C. Therefore, the heating in the bonding process has an influence on the alignment regulating force of the alignment control layer, and good alignment cannot be obtained as compared with the present embodiment. In addition, when the heating temperature of the bonding process was 200 ° C., which is the same as that of the present embodiment, good adhesive strength was not obtained.
[0068]
  As described above, when the liquid crystal display element manufactured by the conventional process described above and the liquid crystal display element according to the embodiment of the present invention are compared, it has been found that the latter is superior in the bonding strength and display quality of the substrate.
[0069]
  [Comparative Example 2]
  In another conventional liquid crystal display element, as shown in FIG. 4, a spacer 6 is formed on an upper layer of the alignment control layer 5a, and the substrates 40 and 20 are aligned on the spacer 6 on the insulating substrate 21a and the alignment on the insulating substrate 1b. It is the structure bonded together by adhesion | attachment with the control layer 5b.
[0070]
  The manufacturing process of the conventional liquid crystal display element is as follows.
[0071]
  The electrode 2a, the light shielding layer 3a, and the insulating film 4a are formed on the surface of the insulating substrate 21a by a process similar to that described with reference to FIGS. 2 (a) to 2 (c).
[0072]
  Next, an orientation film PSI-A-2101 manufactured by Chisso Corporation is applied on the insulating film 4a by a spin coating method so as to have a film thickness of 50 nm, and is baked at about 200 ° C. for 1 hour. Formed.
[0073]
  Next, a negative photosensitive acrylic resin V-259 manufactured by Nippon Steel Chemical Co., Ltd. is applied onto the orientation control layer 5a by a spin coating method so that the film thickness after firing becomes 1.5 μm. Next, a photomask is applied between the light-shielding layer 3a and the region where the electrode 2a is not formed, and a spacer is to be formed, and UV irradiation is performed to remove the non-exposed portion, followed by baking at about 180 ° C. for 1 hour. By doing so, the spacer 6 was formed.
[0074]
  After the spacer 6 was formed in this way, the alignment control film 5a was rubbed to complete the substrate 40. Next, the substrates 40 and 20 are bonded to each other by bonding the spacer 6 and the orientation control layer 5b, and the liquid crystal 7 is sealed in the gap to complete the liquid crystal display element as shown in FIG.
[0075]
  As described above, in the liquid crystal display element according to the comparative example 2, since the spacer 6 is formed on the alignment control layer 5a, the formation process of the spacer 6 affects the alignment control layer 5a.
[0076]
  Embodiments of the present invention and the liquid crystal display device manufactured by the conventional process as described aboveInWhen compared with such a liquid crystal display element, it was found that the latter was superior in display quality.
[0077]
【The invention's effect】
  BookAs described above, the liquid crystal display element of the invention is at least one of the pair of substrates.On the insulating film formed to cover the insulating substrate and the plurality of electrodes.A columnar or wall-like spacer having a uniform height, and the one substrate excluding a portion located at the top of the spacerInsulating film surfaceTo coverDepending on the material repelled by the spacerAn alignment control layer is provided, and the pair of substrates are bonded to each other by bonding a portion located at the top of the spacer to the alignment control layer of the other substrate.
[0078]
  As a result, the alignment control layer can be formed after the spacer is formed, thus avoiding deterioration of display quality due to contamination, alteration, destruction, etc. of the alignment control layer due to the spacer formation process, and restrictions on the material of the spacer or alignment control layer. can do.
[0079]
  In addition, since the pair of substrates are bonded to each other by adhesion between the spacer and the orientation control layer, it is possible to avoid display quality degradation, insufficient adhesive strength, and restrictions on the orientation control layer material due to softening of the orientation control layer.
[0080]
  Therefore, it is possible to realize a good display quality without unevenness and to provide a liquid crystal display element excellent in shock resistance.
[0081]
  further,Even if the alignment control layer is applied so as to cover the entire upper layer of the insulating substrate on which the spacer is formed, the alignment control layer can be selectively formed on the upper layer of the insulating substrate except for the top of the spacer. Therefore, the alignment control layer is not contaminated, broken, and the like, and it is possible to provide a liquid crystal display element with good display quality.
[0082]
  BookThe liquid crystal display element of the invention is as described above.the aboveIn the structure, the spacer is made of a photosensitive organic resin.
[0083]
  Therefore, since a photoresist is not required in the spacer forming step, it is possible to provide a liquid crystal display element having shock resistance and good display quality by a simpler and cheaper manufacturing method.
[0084]
  BookThe liquid crystal display element of the invention is as described above.the aboveIn the configuration, the spacer is a region between the plurality of electrodes on the one substrate.On the insulation filmIt is the structure which is arrange | positioned and has optical isotropy.
[0085]
  Therefore, when the spacer is formed outside the pixel region, it is possible to avoid a decrease in aperture ratio and display quality that occurs when the spacer is formed in the pixel.
[0086]
  In addition, since the spacer has optical isotropy, the spacer can function as a black matrix.
[0087]
  BookThe liquid crystal display element of the invention is as described above.the aboveIn the configuration, the liquid crystal is a ferroelectric liquid crystal.
[0088]
  Thereby, the ferroelectric liquid crystal is sandwiched between the substrates having excellent shock resistance, so that the disadvantage of the ferroelectric liquid crystal that is weak against external pressure is solved. Therefore, it is possible to provide a liquid crystal display element that exhibits the excellent characteristics of the ferroelectric liquid crystal.
[0089]
  BookThe manufacturing method of the liquid crystal display element of the invention is as described above, on at least one of the pair of substrates,On the insulating film formed to cover the insulating substrate and multiple electrodesA first step of forming a plurality of columnar or wall-like spacers of uniform height, and the one substrate except for a portion located at the top of the spacerInsulating film surfaceTo coverDepending on the material repelled by the spacerThe method includes a second step of forming an orientation control layer and a third step of bonding a portion located on the top of the spacer to the orientation control layer of the other substrate.
[0090]
  Thus, since the spacer is formed prior to the formation of the alignment control layer, the alignment control layer is prevented from being contaminated or damaged by the solvent or the like used in the spacer formation process. Further, by selectively forming the orientation control layer so as to cover the insulating substrate upper layer other than the top of the spacer, that is, since the orientation control layer is not formed on the top of the spacer, the pair of substrates is a spacer of one substrate. Are bonded together by adhesion between the top of the substrate and the orientation control layer of the other substrate. Therefore, it is possible to avoid deterioration of display quality and insufficient adhesive strength due to softening of the alignment control layer, which occurs in the case of bonding between alignment films. Therefore, there is an effect that it is possible to provide a liquid crystal display element having good display quality without unevenness and excellent shock resistance.
[0091]
  BookThe manufacturing method of the liquid crystal display element of the invention is the second step,By the material repelled by the spacer so as to cover the surface of the insulating filmIn this method, the orientation control layer is selectively formed outside the spacer formation region.
[0092]
  As a result, the spacer repels the orientation control layer, so even if the orientation control layer is applied so as to cover the entire insulating substrate upper layer on which the spacer is formed, the orientation control layer is selected as the insulating substrate upper layer excluding the top of the spacer. Can be formed. Therefore, the alignment control layer is not contaminated, broken, and the like, and it is possible to provide a liquid crystal display element with good display quality.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid crystal display element according to an embodiment of the present invention.
FIGS. 2A to 2E are cross-sectional views showing respective stages of the manufacturing process of the liquid crystal display element.
FIG. 3 is a cross-sectional view showing a schematic configuration of a liquid crystal display device manufactured by a conventional manufacturing process.
FIG. 4 is a cross-sectional view showing a schematic configuration of another liquid crystal display element manufactured by a conventional manufacturing process.
[Explanation of symbols]
  10.20 Substrate
  5a ・ 5b Orientation control layer
          6 Spacer
          7 Liquid crystal (ferroelectric liquid crystal)

Claims (5)

In a liquid crystal display element in which liquid crystal is sealed between a pair of substrates, at least one of which is light transmissive,
At least one of the pair of substrates includes a columnar or wall-shaped spacer having a uniform height on an insulating film formed so as to cover the insulating substrate and the plurality of electrodes . An orientation control layer is provided by a material repelled by the spacer so as to cover the surface of the insulating film of the one substrate except for the portion located at the top, and the portion located at the top of the spacer is the other substrate. A liquid crystal display element, wherein the pair of substrates are bonded to each other by being adhered to the orientation control layer. The spacer, the liquid crystal display device of claim 1 Symbol mounting characterized by comprising the photosensitive organic resin. The spacer, the disposed on the insulating film in a region between the plurality of electrodes on one substrate, and a liquid crystal display device according to claim 1 or 2, wherein the having optical isotropy. Wherein the liquid crystal, the liquid crystal display device according to any one of claims 1 to 3, characterized in that a ferroelectric liquid crystal. In a method for manufacturing a liquid crystal display element in which liquid crystal is sealed between a pair of substrates, at least one of which has optical transparency,
A first step of forming, on at least one of the pair of substrates, a plurality of columnar or wall spacers having a uniform height on an insulating film formed so as to cover the insulating substrate and the plurality of electrodes ; ,
A second step of forming an orientation control layer with a material repelled by the spacer so as to cover the surface of the insulating film of the one substrate except for a portion located at the top of the spacer;
And a third step of bonding a portion located on the top of the spacer to the orientation control layer of the other substrate.

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